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+                  The Aperture Photometry Package
+                 ----------------------------------
+
+The apphot package contains routines which perform aperture
+photometry in circular and polygonal apertures using fractional pixel
+techniques. No point spread function fitting techniques are employed.
+The photometry routines are most suitable for use on uncrowded
+or moderately crowded fields.
+
+The apphot directory structure is listed below. The package organization
+is by task, for example the center subdirectory contains routines
+specific to the center task or by function, for example the nlfit
+directory contains the non-linear least squares fitting routines.
+The wphot task shares alot of code with the phot task. Similarly
+the polymark task shares some code with the polyphot task.
+The .h files are all in lib as many of them are shared by several tasks.
+
+             |-aplib---------apphot routines used by several tasks
+             |-aputil--------miscellaneous useful routines
+             |-center--------routines specific to centering, the center task
+             |-daofind-------routines specific to the daofind task
+             |-doc-----------apphot documentation
+|-apphot-----|-fitpsf--------routines specific to the fitpsf task
+             |-fitsky--------routines specific to sky fitting, the fitsky task
+	     |-lib-----------apphot definitions or .h files
+             |-phot----------routines specific to the qphot/phot tasks
+             |-polyphot------routines specific to the polyphot/polymark tasks
+             |-radprof-------routines specific to the radprof task
+	     |-wphot---------routines specific to the wphot task
+             |-test----------directory of test data
+
+
+Lindsey Davis
+NOAO IRAF GROUP
+November 1991
diff --git a/noao/digiphot/apphot/Revisions b/noao/digiphot/apphot/Revisions
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+.HELP revisions Jun88 noao.digiphot.apphot
+.nf
+
+
+apphot/wphot/apwmag.x
+    Minor typo where procedure closed with a ']'  (8/19/09, MJF)
+
+apphot/wphot/t_wphot.x
+    A call to apstats() was being passed 'cl' instead of 'ap' (8/19/09, MJF)
+
+apphot/phot/apqradsetup.x 
+apphot/phot/apradsetup.x 
+apphot/wphot/apbwphot.x
+    The ap_wmag() was incorrectly being used as apwmag() (8/17/09, MJF)
+
+apphot/aputil/apvectors.x
+    Modified so the calculation is done in floating point (8/15/09, MJF)
+
+apphot/daofind/apfdcolon.x
+    A call to apsets() was mistakenly using a closed 'cl' pointer instead
+    of the 'ap' apphot struct pointer (8/15/09, MJF)
+
+apphot/radprof/apfrprof.x
+    The cvrject() subroutine was called w/ an extra argument (7/12/09, MJF)
+
+apphot/aputil/apnlfuncs.x
+    1.	Comments now say whether a parameter is a variance or a sigma.
+    2.  Check for zero variance or sigma were improved.  The default value
+    	is a sigma of 6 or a variance of 36.
+    3.  CGAUSS1D was setting the wrong variable (z instead of r2) when
+    	a zero variance is found.
+    (3/18/09, Valdes: reported by Jason Quinn)
+
+aplib/apwparam1.x
+     The CLEAN parameter was being printed with UN_CSCALEUNIT units instead
+     of UN_CSWITCH (7/8/08, MJF)
+
+aplib/apwparam1.x
+     The format string had 'yyy' instead of 'yyyy'.
+      (5/27/08, Valdes)
+
+apphot/fitpsf/apsffit.x
+apphot/phot/apmag.x
+apphot/phot/apremag.x
+apphot/wphot/apwmag.x
+apphot/wphot/apwremag.x
+     Fixed some procedure calls being closed with a ']' instead of a ')'
+     (2/17/08, MJF)
+
+=======
+V2.12.3
+=======
+
+apphot/aputil/apnlfuncs.x
+    Catch error when the input sigma is zero.  (5/2/05, Valdes)
+
+=======
+V2.12.2
+=======
+
+apphot/aputil/aptopt.x
+    Catch error when the input sigma is zero.  (2/24/03, Valdes)
+
+apphot/center/t_center.x
+apphot/fitpsf/t_fitpsf.x
+apphot/fitsky/t_fitsky.x
+apphot/phot/t_phot.x
+apphot/phot/t_qphot.x
+apphot/polyphot/t_polyphot.x
+apphot/radprof/t_radprof.x
+apphot/wphot/t_wphot.x
+    The handling of the "default" parameter value for coordinate lists
+    failed when the input list had more than one image.  The way this
+    was done relied on a string not being modified but it was being
+    modified in a call to apfroot.  (9/30/02, Valdes)
+
+=======
+V2.12.1
+=======
+
+apphot/center/apcenter.x
+apphot/fitpsf/apfitpsf.x
+apphot/fitsky/apsky.x
+apphot/phot/apphot.x
+apphot/polyphot/apyhot.x
+apphot/radprof/apradprof.x
+apphot/wphot/apwphot.x
+    Fixed problems with the 'v' that can occur if the same star is measured
+    with different parameters without an intervening cursor move.
+
+    Davis, June 20, 2002
+
+apphot/fitsky/mkpkg
+    declaration. Added a missing <imhdr.h> file dependency to the apsky.x
+    declaration.
+
+    Davis, December 13, 2001
+
+apphot/daofind/mkpkg
+    Removed an unnecessary ../lib/display.h file dependency from the apbfdfind
+    declaration. Added a missing ../lib/display.h file dependency to the
+    apfdcolon.x declaration.
+
+    Davis, December 13, 2001
+
+apphot/aputil/appcache.x
+    Added a call setting IM_BUFFRAC to 0 to the memory caching code in the
+    apphot package tasks in order to force the imio buffer to be the size of
+    the input image.
+
+    Davis, December 10, 2001
+
+apphot/center/apcenter.x
+    Fixed a boolean / integer conversion problem in the interactive variable.
+    This bug should not be present in released code.
+    
+    Davis, September 19, 2001
+
+apphot/polyphot/apymkinit.x
+    The call to ap_defsetup was missing the fwhmpsf argument. Since
+    this is never used in the code this bug may not cause a problem.
+
+    Davis, September 19, 2001
+
+apphot/aplib/apwres2.x
+     The pargr routine was being called with a double precision constant
+     0.0d0 argument.
+
+    Davis, September 19, 2001
+
+apphot/fitsky/apcentroid.x
+    Fixed a real/double type mismatch in a call to alimr.
+
+    Davis, September 19, 2001
+
+apphot/
+    Modified all the apphot tasks to accept input coordinates in logical, tv,
+    physical, or world coordinates and to write the output coordinates in
+    logical, tv, or physical coordinates. One consequence of this is that
+    the apphot tasks will now work correctly off image sections in interactive
+    mode. Another is that users can work on image sections while preserving
+    the coordinate system of the entire image.
+
+    Davis, May 30, 2000
+
+apphot/
+    Modified all the apphot tasks to strip the directory information from
+    the input image and coordinate file names written to the output files,
+    to the terminal, and to the plot headers. The colon commands will still
+    read and write full image and coordinate file path names. This change
+    improves the likelyhood  that the full root image name will be written
+    to the output. This root image name is used by the photometric calibration
+    code to construct images sets.
+
+    Davis, April 19, 2000
+
+apphot/*/mkpkg
+    Added some missing file dependencies and deleted some unecessary ones
+    from the mkpkg files.
+
+    Davis, September 20, 1999
+
+apphot/polyphot/apyfit.x
+apphot/polyphot/appyerrors.x
+apphot/aplib/apwres2.x
+    Improved the error reports for polyphot in the case where the effective
+    aperture is 0, which may occur if the polygon is off the image or due
+    to fractional pixel effects.
+
+    Davis, August 10, 1999
+
+apphot/polyphot/apyget.x
+apphot/polyphot/apmkpylist.x
+apphot/polyphot/ayphot.x
+apphot/polyphot/apyradsetup.x
+    Modified the polygon drawing code (the g keystroke command) to flush
+    the graphics buffer after every polygon segement is drawn instead
+    of after the polygon is complete.
+
+    Davis, July 9, 1999
+
+apphot/aputil/apotime.x
+    Modified the code which reads the time of observation value from the image
+    header to extract the time field from the date-obs keyword if it is
+    present.
+
+    Davis, May 11, 1999
+
+apphot/aputil/apdate.x
+    Modified the date and time photometry file keyword encoding tasks to
+    write the date and time in the proper fits format and in units of GMT.
+    Note that GMT is deactivated in digiphotx because the necessary routine
+    is not yet in the system.
+
+    Davis, May 11, 1999
+
+apphot/aputil/apfnames.x
+    Modified the default input and output file nameing routines to handle
+    input images with kernel sections and cluster indices more gracefully.
+
+    Davis, January 17, 1999
+
+apphot/aplib/apwparam1.x
+apphot/aputil/apdate.x
+    Modified the apphot output file writing routines to write the "DATE"
+    keyword in the new FITS standard format, eg. yyyy-mm-dd instead of
+    mm-dd-yy.
+
+    Davis, December 29, 1998
+
+apphot/daofind/t_daofind.x
+    Modified the default output file naming code to support names of the
+    form "directory/default" as well as "default" in interactive mode
+    as well as non-interactive mode.
+
+    Davis, February 13, 1998
+
+apphot/daofind/apfind.x
+    Modified the centering routines to protect against a rare floating
+    divide by 0 condition.
+
+    Davis, June 24, 1997
+
+apphot/aptest.cl
+    Modified the rfits calling sequence so that the test script will
+    run correctly with the new version of rfits.
+
+    Davis, May 29, 1997
+
+apphot/daofind/apfind.x
+    Modified the routine that computes the new roundness parameter to check
+    for <= 0.0 quantities in the denominator of the new roundness statistic.
+    Zero valued quantities can in rare cases cause a divide by zero or
+    floating operand error.
+
+    Davis, July 21, 1996
+
+apphot/lib/polyphotdef.h
+apphot/aplib/apset1.x
+apphot/aplib/apset2.x
+apphot/aplib/apset.x
+apphot/aplib/apstat1.x
+apphot/aplib/apstat2.x
+apphot/aplib/apstat.x
+apphot/aplib/apwres2.x
+apphot/aplib/aparrays.x
+apphot/aplib/aprcursor1.x
+apphot/aplib/mkpkg
+apphot/phot/apmag.x
+apphot/phot/apremag.x
+apphot/phot/appinit.x
+apphot/phot/appfree.x
+apphot/phot/appplot.x
+apphot/phot/apmeasure.x
+apphot/phot/apcomags.x
+apphot/phot/mkpkg
+apphot/wphot/apwmag.x
+apphot/wphot/apwremag.x
+apphot/wphot/apgmeasure.x
+apphot/wphot/aptmeasure.x
+apphot/wphot/mkpkg
+apphot/radprof/apfrprof.x
+apphot/radprof/aprpindex.x
+apphot/radprof/aprpplot.x
+apphot/radprof/aprmmeasure.x
+apphot/polyphot/apyfit.x
+apphot/polyphot/mkpkg
+    Modified the aperture sum routines to work in double precision where
+    appropriate. This avoids rounding errors that become visible when
+    working on synthetic data or data with neglible sky noise.
+
+    Davis, July 18, 1996
+
+apphot/doc/qphot.hlp
+    Fixed some typos / omissions in the qphot help page.
+
+    Davis, April 11, 1996
+
+apphot/apphot.cl
+apphot/apphot.men
+    Replaced the txdump task with the more general pdump task and added the
+    pcalc, pconvert, prenumber, pselect, and psort tasks to the apphot
+    package.
+
+    Davis, March 15, 1996
+
+apphot/aplib/apwres1.x
+apphot/daofind/apfind.x
+    Fixed a serious bug in the daofind centering code which resulted
+    in incorrect fractional pixel corrections being computed. This error
+    can most easily be detected by plotting the histogram of the fractional
+    pixel corrections for an image with a large number of detected objects.
+    The histogram will be modulated with "peaks" around the .33 and .66
+    fractional pixel values.
+
+    This bug is also present in the standalone version of daophot ii. User
+    should obtain a new version of daophot ii from Peter Stetson.
+
+    Added a new roundness statistic to daofind. This statistic is sensitive
+    to objects which are elongated in directions other than x and y.
+
+    Davis, March 15, 1996
+
+apphot/center/apcenter.x
+apphot/fitpsf/apfitpsf.x
+apphot/fitsky/apsky.x
+apphot/phot/apphot.x
+apphot/phot/apqphot.x
+apphot/polyphot/apyphot.x
+apphot/radprof/apradprof.x
+apphot/wphot/apwphot.x
+    The new m keystroke command was doing exactly the same thing as the n
+    keystroke command due to a confusion of the key and colonkey variables.
+
+    Davis, Feb 12, 1996
+
+apphot/doc/centerpars.hlp
+apphot/center/mkpkg
+apphot/center/apfitcen.x
+apphot/center/aprefitcen.x
+apphot/center/apcplot.x
+apphot/aputil/apgtools.x
+    Modified the centering algorithm code to recognize 3 separate cases:
+    1) cthreshold = 0.0 invokes the default thresholding technique for
+    each algorithm, 2) cthreshold = +val sets the threshold to  some
+    value above (below) the local data minimum (maximum), 3) cthreshold=INDEF
+    or undefined turns off all thresholding. This change does not
+    change the default behavior of the code.
+
+    Changed the definition of local data minimum from the minimum pixel
+    in the centering box to the minimum median value for each row in the
+    centering box. This gives a value much closer to the background values
+    and protects against very low valued pixels in the centering box defining
+    the thresholding level.
+
+    Davis, Sept 29, 1995
+
+apphot/fitsky/apskybuf.x
+    Changed the misleading error return code from AP_SKY_OUTOFBOUNDS to
+    AP_NSKY_TOO_SMALL in the case when all the sky  are out of the good
+    data range.
+
+    Davis, June 22, 1995
+
+apphot/daofind/apfind.x
+    Added a check to avoid a divide by zero error in the code which computes
+    the x and y positions of the detected objects. The divide by zero error
+    can occur when the datamin value is too high for the image and there
+    are not enough points to accurately compute the new x and y position.
+
+    Davis, June 19, 1995
+
+apphot/aplib/mkpkg
+apphot/aplib/apwres1.x
+apphot/aplib/apwres2.x
+apphot/aplib/apwres3.x
+apphot/aplib/apwres4.x
+apphot/doc/phot.hlp
+apphot/doc/polyphot.hlp
+apphot/doc/qphot.hlp
+apphot/doc/radprof.hlp
+apphot/doc/wphot.hlp
+    Added a FLUX column to the output of the PHOT, POLYPHOT, QPHOT, RADPROF,
+    and WPHOT tasks and updated the appropriate help pages.
+
+    Davis, Nov 14, 1994
+
+apphot/daofind/apfdstars.x
+apphot/daofind/apbfdfind.x
+    Added a missing check for an INDEF value of sigma that could cause
+    a floating point overflow in daofind when run from the APPHOT package
+    with the default parameters.
+
+    Davis, Oct 20, 1994
+
+apphot/aplib/apwres2.x
+    Added a check to make sure that the OTIME and IFILTER fields do not
+    overflow the 23 character space allotted for them in the output file.
+
+    Davis, Oct 12, 1994
+
+apphot/center/t_center.x
+apphot/daofind/t_daofind.x
+apphot/fitpsf/t_fitpsf.x
+apphot/fitsky/t_fitsky.x
+apphot/phot/t_phot.x
+apphot/phot/t_qphot.x
+apphot/polyphot/t_polymark.x
+apphot/polyphot/t_polyphot.x
+apphot/radprof/t_radprof.x
+apphot/wphot/t_wphot.x
+    Fixed a bug in the default input and output file naming code which was
+    causing the directory specifications to be stripped from the names.
+
+    Davis, Oct 4, 1994
+
+apphot/phot/apphot.x
+apphot/phot/apqphot.x
+apphot/wphot/apwphot.x
+apphot/polyphot/apyphot.x
+apphot/radprof/apradprof.x
+apphot/phot/phot.key
+apphot/phot/qphot.key
+apphot/wphot/wphot.key
+apphot/polyphot/polyphot.key
+apphot/radprof/radprof.key
+apphot/doc/phot.hlp
+apphot/doc/qphot.hlp
+apphot/doc/wphot.hlp
+apphot/doc/polyphot.hlp
+apphot/doc/radprof.hlp
+    Added a new keystroke command 'a' to the phot, qphot, wphot, polyphot
+    and radprof commands. The a keystroke command compute a sky value
+    by averaging several sky values sampled in different regions of the
+    image. Basically it is a loop over the the t keystroke command.
+    The sky value in each region is computed using the current algorithm
+    and geometry and the individual sky, sky sigma and sky skew values
+    are averaged to produce a final sky, sigma and skew, whereas the
+    number of sky pixels and number of rejected sky pixels are summed.
+    The a keystroke command is intended for use with the p and o keystroke
+    commands to produce an offset sky measurement capability.
+
+    Davis, Feb 10, 1994
+
+apphot/fitpsf/apsffit.x
+apphot/fitpsf/apsfrefit.x
+apphot/aplib/apwres4.x
+    1. Modified the fitpsf task fitting routines so that the  parameter and
+    parameter error arrays are initialized to INDEF (instead of being left
+    with the values from the previous fit), in the case that the
+    fitting box is entirely off the image or that that there are too few
+    pixels in the fitting box to fit the model psf. 
+    2. Modified the output formatting routines to print the errors in 
+    the fitted rsigma (function=radgauss), xsigma and ysigma (function=
+    elgauss), and rgyrat and ellip (function=moments) to three decimal
+    places instead of two.
+
+    Davis, Jan 17, 1994
+
+apphot/center/t_center.x
+apphot/fitpsf/t_fitpsf.x
+apphot/fitsky/t_fitsky.x
+apphot/phot/t_phot.x
+apphot/polyphot/t_polyphot.x
+apphot/phot/t_qphot.x
+apphot/phot/t_radprof.x
+apphot/wphot/t_wphot.x
+    If the number of input images was greater than one, the number of output
+    files exactly equal to one, and the input coordinate file for the image
+    did not contain any decodable coordinates the coordinate file rather
+    than the empty output file is deleted. This was ocurring because the
+    output file was not being correctly stored each time through the image
+    loop and empty output files are deleted by the apphot tasks.
+
+    Davis, Dec 31, 1993
+
+apphot/fitsky/aprefitsky.x
+    The SCALE parameter in the call to ap_crossor was incorrectly
+    dereferenced as AP_SCALE(sky) instead of AP_SCALE(ap).
+
+    Davis, Sep 13, 1993
+
+apphot/aplib/apinpars2.x
+    The shiclip parameter, default = 0.0, was incorrectly being set to the
+    value of the sloclip parameter at startup time.
+
+    Davis, Sep 9, 1993
+
+apphot/center/aprefitcen.x
+    The CMAXITER parameter was incorrectly referenced in the call to 
+    the ap_lgctr1d routine inside the routine aprefitcenter.
+    This centering routine is not often used, and the bug is trigggered
+    only if an object is recentered using different algorithm parameters
+    but the same image data, something only likely to occur in interactive
+    mode.
+
+    Davis, Sep 6, 1993
+
+apphot/center/apcencolon.x
+    The arugument cmdstr in the routine apcentercolon was declared as
+    "char cmdstr" instead of "char cmdstr[ARB]. This has not caused any
+    errors in the code but is poor style.
+
+    Davis, Sep 6, 1993
+
+apphot/phot/apgqppars.x
+apphot/doc/qphot.hlp
+apphot/fitskypars.par
+apphot/doc/fitskypars.hlp
+    Changed the default sky fitting algorithm for the qphot and phot tasks from
+    "mode" to "centroid" with histogram smoothing, to minimize problems
+    with data taken at low light levels which have poorly sampled 
+    histograms.
+
+    Davis, Aug 14, 1993
+
+apphot$
+    The sky fitting routines were revised. Two new parameters, ploclip and
+    phiclip, which define the percentage of  pixels to clip on the low
+    and high sides of the sky pixel distribution were added to fitskypars. The
+    fitskypars parameter skreject was split into two parameters
+    sloreject and shireject which define the low and high side rejection
+    parameters respectively. For the mean, median, and mode algorithms
+    the first rejection cut is now made below sky - min (smax - sky, sky - smin,
+    sloreject * skysigma) and above sky + min (smax - sky, sky - smin, 
+    shireject * skysigma) where sky is the first estimate of the mean, median,
+    and median of the sky pixels respectively, instead of below and above the
+    skreject rejection limits alone. The median is computed using
+    the average of 5% of the pixels around the median instead of 10 pixels.
+    All the histogram dependent algorithms: histplot, centroid, gauss,
+    crosscor, ofilt now use the median of the sky pixels as the center
+    of the histogram, and define the extent of the
+    histogram in a manner similar to that used for the first cut in
+    the mean, median, and mode algorithms. The sigma parameter is
+    no longer used to define the extent and binsize of the sky histogram.
+    Instead the computed sky sigma is used.
+
+    Added m and n keys to the apphot tasks. These keys operate in the same
+    way as the :m and :n keys which have no arguments.
+
+    Added the o key to the apphot tasks. This behaves in the same way
+    as the p key but outputs the results to the output results file.
+
+    Davis, Feb 24, 1993
+
+apphot/aputil/apgflags.x
+    Removed this routine which was not being used and referenced gio.h from
+    the apphot library.
+
+    Davis, Feb 11, 1993
+
+apphot/daofind
+
+    Added the findpars pset to the daofind task and removed the parameter
+    threshold from datapars to findpars. All the detection algorithm
+    parameters moved to findpars.
+
+    Changed the name of the output convolved image to starmap. Added
+    an option to output the best fit sky image skymap.
+
+    Davis, Sept 17, 1992
+
+apphot$
+    Modified all tasks (daofind, center, fitpsf, fitsky, phot, polymark,
+    polyphot, qphot, radprof, and wphot) that were designed to draw marks
+    on the image display to use the imd kernel. All graphics
+    drawing commands are done with portable gio calls. A temporary routine
+    which uses the imd interface to fetch the display device viewport and
+    window is called each time a new image is mapped. A warning message
+    is issued if the image is not loaded in the display and the default
+    full frame viewport is used.  All display drawing is done to the
+    current frame, even if the current frame is not the frame containing
+    the image. The imd kernel does not support the gflush command so
+    a gframe command is used instead. This can create a messy metacode
+    file but is a reasonable approximation for interactive use. 
+
+    Davis, Sep 2, 1992
+
+apphot$phot/apphotcolon.x
+apphot$phot/apqcolon.x
+apphot$radprof/aprpcolon.x
+apphot$wphot/apwpcolon.x
+apphot$wphot/aptmeasure.x
+apphot$wphot/apgmeasure.x
+apphot$aplib/apverify1.x
+apphot$daofind/apfcolon.x
+apphot$fitpsf/apppsf.x
+apphot$fitpsf/apsfcolon.x
+apphot$polyphot/apycolon.x
+    Added some missing sfree statements.
+
+    Davis, Sep 2, 1992
+
+apphot$fitsky/aplgsky,x
+    The test "if (ier != AP_OK)" was being made instead of the proper test
+    "if (iter < 0)". The local variable ier was never defined or used which 
+    tripped a bug in the DEC fortran compiler.
+		
+    Davis, August 3, 1992
+
+apphot$datapars.par
+apphot$centerpars.par
+apphot$doc/datapars.hlp
+apphot$doc/centerpars.hlp
+apphot$lib/noisedef.h
+apphot$lib/noise.h
+apphot$lib/centerdef.h
+apphot$lib/center.h
+apphot$center/apcinit.x
+apphot$center/apcencolon.x
+apphot$center/apcshow.x
+apphot$center/apcconfirm.x
+apphot$center/apcplot.x
+apphot$center/apfitcen.x
+apphot$center/refitcen.x
+apphot$aplib/apinit.x
+apphot$aplib/apnscolon.x
+apphot$aplib/apnshow.x
+apphot$aplib/apinpars.x
+apphot$aplib/apoutpars.x
+apphot$aplib/aprcursor1.x
+apphot$aplib/apverify1.x
+apphot$aplib/apset2.x
+apphot$aplib/apstat2.x
+apphot$aplib/apwparam1.x
+    Changed the units of the cthreshold parameter to sigma and moved it
+    to the centerpars parameter set.
+
+    Davis, July 7, 1992
+
+apphot$center/t_center.x
+apphot$fitpsf/t_fitpsf.x
+apphot$fitsky/t_fitsky.x
+apphot$phot/t_phot.x
+apphot$phot/t_qphot.x
+apphot$polyphot/t_polyphot.x
+apphot$radprof/t_radprof.x
+apphot$wphot/t_wphot.x
+    1. The apphot tasks center, fitspf, fitsky, phot, qphot, polyphot,
+    radprof, anbd wphot were not closing the coordinate files correctly
+    in the case that coords="default" was the length of the coordinate
+    list was being incorrectly set to 1.
+
+    Davis, June 24, 1992
+
+apphot$aplib/apapcolon.x
+    1. The interactive :image <imname> command was not updating the time of
+    observation correctly since the obstime keyword was not being read.
+
+    Davis, June 23, 1992
+
+apphot$polyphot/apyfit.x
+    1. Improved the precision of the polyphot fractional pixel algorithm.
+
+    Davis, April 1, 1992
+
+apphot$polyphot/apyfit.x
+    1. The intersection points of an image line and a polygon could
+    be incorrectly translated into a list of ranges if the polygon was
+    concave and contained a side collinear with the image line.
+
+    Davis, February 25, 1991
+
+apphot$daofind/apfdstars.x
+    1. Removed an extraneous "include <fset.h> statement from daofind.
+
+    Davis, November 20, 1991
+
+    *** Ran spplint on the apphot code
+
+apphot$daofind/apfshow.x
+apphot$aplib/apnshow.x
+apphot$aplib/apqshow.x
+apphot$aplib/apwparam1.x
+    1. Fixed several places in the code where the boolean function itob
+    was declared an integer.
+
+apphot$aplib/apoutpars.x
+    1. Removed an extra maxch argument  from all the clppset calls.
+
+apphot$fitpsf/apppfpars.x
+apphot$phot/apqppars.x
+    1. Removed an extra argument from the clpstr call.
+
+apphot$aplib/aprcursor2.x
+    1. The call to ap_rparam in ap_cpapert was being made with the integer
+    argument PSFAPERT instead of the string argument KY_PSFAPERT.
+
+apphot$fitsky/apskycolon.x
+    1. The calls to ap_apcolon and ap_nscolon were being made with a type
+    real junk variable instead of a type in junk variable. This was harmless.
+
+apphot$fitsky/apspshow.x
+    1. Changed a pargi call to a pargb call.
+
+    Davis, Oct 7, 1991
+
+apphot$test/aptest.cl
+    1. Made some minor formatting changes to the aptest CL script.
+
+    Davis, Aug 23, 1991
+
+apphot$aplib/apfrprof.x
+    1. Radprof was incorrectly normalizing the integral of the total intensity,
+    by failing to multiply by the step size.
+
+    Davis, Aug 23, 1991
+
+apphot$aplib/apwres2.x
+apphot$radprof/apprprof.x
+    1. Changed the unit on output for the radial profile and fwhm from "pixels"
+    to "scale".
+
+    Davis, Aug 23, 1991
+
+apphot$aplib/apwres1.x
+    1. Changed the unit for RAPERT on output from "pixels" to "scale".
+
+    Davis, Aug 23, 1991
+
+apphot$
+    1. Support for picking up the time of observation, for example UT,  was
+    added to all the apphot routines. 
+
+    2. Apphot will now print out INDEF for all object which have bad data
+    inside the photometry apertures.
+
+    3. Whitespace  is stripped from the filter id and the iraf version
+    definition before either of these quantities is written to the photometry
+    files.
+
+    4. The output file header parameters are now 23 characters long instead
+    of 15.
+
+    5. The numerical values of the error codes have been changed for book-
+    keeping purposes.
+
+    Davis, August 1, 1991
+
+apphot$apselect/
+    1. Added the replacement task for apselect, txdump, to the package. 
+
+    2. Added the pexamine task to the package.
+
+    3. Removed the apselect subdirectory.
+
+    Davis, July 29, 1991
+
+apphot$qphot/
+apphot$polymark/
+apphot$nlfit/
+
+    1. Moved all the routines in the qphot subdirectory into the phot 
+    subdirectory and deleted the qphot subdirectory.
+
+    2. Moved all the routines in the polymark subdirectory into the polyphot 
+    subdirectory and deleted the polymark subdirectory.
+
+    3. Removed the old nlfit library from the apphot package and replaced it
+    with the new version which has been installed in the math package.
+    The affected algorithms are the gauss centering algorithm, the gauss
+    sky fitting algorithm, and the fitpsf task radial and elliptical gaussian
+    function fitting algorithms.
+
+    4. The errors computed by the gauss centering routine are smaller in the
+    new version than the old version as the old code was dividing by sqrt
+    (nfree) instead of sqrt (npts).
+
+    Davis, July 28, 1991
+
+apphot$fitpsf/apsffit.x
+apphot$fitpsf/apsfrefit.x
+apphot$fitpsf/apsfradgauss.x
+apphot$fitpsf/apsfelgauss.x
+    1. The errors computed by the fitpsf radial and elliptical gaussian
+    fitting routines are smaller in the new version than the old version
+    as the old code was dividing by sqrt (nfree) instead of sqrt (npts).
+
+    2. The error output for rsigma in the fitpsf radial gaussian fitting
+    routine and for xsigma/ysigma in the elliptical gaussian fitting routines
+    in the old code was actually the error in rsigma ** 2 or xsigma ** 2
+    and ysigma ** 2 respectively.  These errors were too small.
+
+    Davis, July 28, 1991
+
+apphot$center/apfitcen.x
+apphot$center/aprefitcen.x
+apphot$center/apgctr1d.x
+apphot$center/aplgctr1d.x
+apphot$aputil/aptopt.x
+apphot$aputil/apqzero.x
+    1. Modified all the centering routines so that the fitted centers are
+    contrained to stay in the fitting box after each iteration. The gauss
+    algorithm in particular could runaway when fitting objects near the
+    edge of the frame or very weak objects.
+
+    2. Fixed a bug in the optimal filter algorithm wherein the
+    normalization procedure could fail if there wa no star in the
+    centering box.
+
+    Davis, May 30, 1991
+
+apphot$center/apcconfirm.x
+apphot$fitsky/apsconfirm.x
+apphot$phot/appconfirm.x
+apphot$wphot/apwconfirm.x
+apphot$polyphot/apyconfirm.x
+apphot$radprof/aprconfirm.x
+apphot$fitpsf/appsfconfirm.x
+    1. Modified all the apphot task verify routines to verify datamin and
+    datamax.
+
+    Davis, Mar 29, 1991
+
+apphot$nlfit/nliter.x
+apphot$nlfit/nlacpts.x
+    1. Modified nlfit routines to get rid of the wtflag argument in those
+    routines where it was not actually used.
+
+    Davis, Nov 20, 1990
+
+apphot$aputil/apwlimr.x
+apphot$fitpsf/apsfradgauss.x
+apphot$fitpsf/apsfelgauss.x
+apphot$fitpsf/apsffit.x
+apphot$fitpsf/apsfrefit.x
+    1. Modified the fitpsf task so the the radial gaussian and elliptical
+    gaussian fitting routines use the maximum (emission objects) or
+    minimum (absorption objects) pixel position as the first guess for
+    a good position instead of the center position.
+
+    Davis, Nov 16/1990
+
+apphot$daofind/apbfdfind.x
+apphot$daofind/apconvolve.x
+apphot$daofind/apfdstars.x
+    1. Fixed a bug in the batch mode execution of DAOFIND wherein
+    DAOFIND quit with an "cannot write pixel file error" when run on
+    a previously existing convolved image.  This bug was introduced by the
+    Mar 12 1990 bugfix.
+
+    Davis, Nov 8, 1990
+
+apphot$polyphot/t_polyphot.x
+apphot$lib/polyphot.h
+    1. Changed the default size of MAX_NVERTICES from 100 to 900 to satisfy
+    some surface photometry people. Removed a redundant MAX_NVERTICES
+    declaration in t_polyphot.x
+
+    Davis, Aug 24, 1990
+
+apphot$phot/apmagbuf.x
+   1. Phot was refusing to fit stars whose apertures were < 1.0 pixels from
+   the edge of the image because the out-of-bounds criterion was too
+   conservative. I modified the code to remove this problem.
+
+    Davis, Aug 6, 1990
+
+apphot$daofind/apbfdfind.x
+apphot$daofind/apfdstars.x
+apphot$daofind/apfind.x
+    1. Changed the daofind program to automatically include the relative
+    error in the detection threshold.
+
+Davis, July 17, 1990
+
+apphot$fitsky/apskybuf.x
+    1. In a few cases due to fractional pixel effects the skyfitting
+    routines were not preallocating sufficient space to hold the sky
+    pixels resulting in a memory corruption error.
+
+    Davis, June 27, 1990
+
+apphot$aplib/apfrprof.x,mkpkg
+    1. Modified radprof so that it would integrate 2*PI*r*I instead of
+    just I itself.
+
+    Davis, June 18, 1990
+
+apphot$aplib/apfdres.x
+    1. Renamed the round and sharp parameters to roundness and sharp to
+    remove and ambiguity in the naming convention.
+
+    Davis, May 24, 1990
+
+apphot$daofind/apconvolve.x
+    1. Added an imflush after the last write in apconolve which cured
+    a "pixel file is truncated error". This error showed up when
+    daofind was run on an image that was 641 by 1025 but not on
+    one that was 640 by 1024. Apparently this problem has been there
+    all along but only occurs very rarely.
+
+    Davis, Mar 29, 1980
+
+apphot$aptest.cl
+apphot$aptest.par
+    1. Added the aptest task to the apphot package.
+
+    Davis, Mar 19, 1990
+
+apphot$aplib/
+    1. Fixed two bugs in the output formating code. Long file names could
+    overflow the fixed format space allotted and destroy the syntax of the
+    file making it impossible for apselect to decode it. Second the COORDS
+    parameter was mistakenly typed as integer instead of string.
+    Davis, Mar 14, 1990
+
+apphot$daofind/
+    1. Fixed a bug which was causing daofind to fail to compute the convolved
+    image when the input and output images were in hhh format. The hhh format
+    was failing the test [if (IM_PIXFILE(im) == EOS)] as the pixel
+    file names are set at different places in the oif and stf kernel.
+    The test was dangerous and redundant, and has been removed.
+
+    Davis, Mar 12, 1990
+
+apphot$qphot/mkpkg
+    1. Removed a duplicate entry for apqcolon.x from the mkpkg file.
+
+    Davis, Feb 20, 1990
+
+apphot$center/apcsnratio.x
+    1. Recoded this routine slightly to avoid an optimizer bug in
+    the 386i version.
+
+    Davis, Feb 13, 1990
+
+apphot$center/apcinit.x
+apphot$fitsky/apsinit.x,apsplot.x
+apphot$phot/appplot.x
+    1. The sky fitting algorithm string was not being correctly set if
+    salgorithm was "gauss" or "median" resulting in garbage in the output
+    file header. The correct algorithm was being used.
+
+    2. A floating point error would occur if salgorithm = "constant",
+    sigma = "INDEFR" and radial profile plotting was enabled. The problem
+    occurred because the plot was trying to draw the 3 * sigma of the
+    sky line by adding the sky value and the sky sigma which is INDEFR.
+
+    3. Disabled plotting the centering pixel buffer in the case where
+    "calgorithm" was none and the sky pixel buffer when salgorithm is
+    "none".
+
+    Davis, Feb 7, 1990
+
+apphot$fitpsf/apfitpsf.x
+apphot$fitpsf/aprefitpsf.x
+    Fixed a bug in the weighting scheme for fitpsf in which the gain was
+    not scaling the image intensities correctly. I also added a check
+    for 0 valued weights.
+
+    Davis, Jan29, 1990
+
+apphot$
+    Added a setup menu mode to all the apphot tasks. When the user types
+    i they enter the setup menu instead of a pre-defined set of commands.
+    The default setup is still available as the v key, but each parameter
+    can now be set individually as well.
+
+    The documentation has been brought up-to-date.
+
+    Davis, Jan 29, 1990
+
+apphot$phot/t_phot.x
+
+    Added calls to ap_airmass and ap_filter to the phot task as the filter
+    and airmass were not updating correctly.
+
+    Davis, Jan 16, 1990
+
+apphot$
+    Four new parameters airmass, xairmass, filter, ifilter were added to
+    the datapars task  to permit users to pick up the filter and airmass
+    quantities form the image headers for later transmission to calibration
+    programs.
+
+    Davis, Nov 28, 1989
+
+apphot$radprof.par
+    The default value of the verbose parameter in radprof was yes
+    instead of no as it should have been.
+
+    Davis, Nov 28, 1989
+
+apphot$
+    Added a new algorithm "mean" to the sky fitting options.
+
+    Davis, Nov 17, 1989
+
+apphot$
+    Added an update parameter to all the apphot tasks. If verify is yes
+    and the task is run in non-interactive mode update will update
+    the critical parameters into the psets.
+
+    Davis, Nov 16, 1989
+
+apphot$radprof/t_radprof.x
+    Removed a defunct define MAX_NAPERTS 15 statement from the
+    radprof task. It now uses the definition in phot.h like all
+    the other tasks.
+
+    Davis, Nov 9, 1989
+
+apphot$daofind/
+    Changed daofind so that a new .coo file is output everytime daofind
+    is run in interactive mode.
+
+    Davis, Oct 30, 1989
+
+apphot$fitsky/apmode.x
+    Made some subtle mods to the mode fitting algorithm. In particular
+    only the first cut is made around the median the remainder are around
+    the mode.
+
+    Davis, October 11, 1989
+
+apphot$
+    1.  apphot$center, fitsky, phot, wphot, polyphot, fitpsf and radprof tasks
+    Activated the datamin and datamax parameters. Pixels outside
+    this range are rejected from sky fitting algorithms and from the
+    non-linear least squares fits in fitpsf and radprof. If a bad pixel
+    is in the centering aperture or in a photometry aperture a magnitude
+    is still computed but a warning message is issued.
+
+    The only task where these parameters are not currently implemented
+    is daofind, pending algorithm review.
+
+    2. apphot$polyphot/apyphot.x
+    Added a keystroke option to fit polygons that are not shifted to the
+    current cursor position.
+
+    3. apphot$fitsky/aprefitsky.x
+    Fixed an error in the stellar position reported on the plot in the
+    radplot option for sky fitting. The last cursor position was not
+    being reported.
+
+    4. apphot$fitsky/apmode.x
+    Changed the cut to one around the mode. Things look ok.
+
+    Davis, October 10, 1989
+
+apphot$apselect/apkeywords.x
+    1. Fixed a bug in the apselect task. Apselect was not picking up changes
+    int the keywords (#K) values correctly. The pointer in the ky_addval
+    procedure was being incorrectly computed and the new value was being
+    put in the wrong place.
+
+    Davis, Sept 15, 1989
+
+apphot$
+    1. I removed the query for fwhmpsf from phot.
+
+    2. I fixed a serious problem in daofind when interactive = yes and
+    the task was rerun on the same convolved image but using a new
+    threshold. There was also a problem with the naming of the
+    temporary image.
+
+    Davis, Aug 22, 1989
+
+apphot$aplib/aprcursor.x
+apphot$aplib/apradpsf.x 
+
+    1. The prompt for the psf fitting box parameter box has been changed from
+    "centering radius" to "fitting box half width".
+    The prompt for the centering box parameter cbox has been changed from
+    "centering radius" to "centering box half width".
+
+    2. The code to quickly center the radial profile before fitting has
+    been added to the interactive setup routine. Somehow the fitpsf
+    task was overlooked when this update was made originally.
+
+    Davis, Aug 1, 1989
+
+apphot$aprcursor.x
+    The procedure ap_caper() inside apphot$aplib/aprcursor.x was define as
+    a type real procedure but called as a subroutine. I removed the type
+    real declaration.
+
+    Davis, July 31, 1989
+
+Version 2.8 export
+
+*************************************************************************
+
+apphot$
+    1. The inverse of the scale was being incorrectly printed out by
+    the :show command.
+
+    2. Fwhmpsf is in scale units not pixels as listed in datapars.
+
+    3. Exposure, ccdread and gain were not being updated correctly
+    in interactive mode.
+
+    Davis, June 20, 1989
+
+apphot$
+    1. A new parameter scale has been added to datapars and integrated into
+    the apphot tasks. All the radial profile plots will now display
+    units of scale and of pixels. The .hlp. .key and : commands
+    have all be changed appropritately. Testing is complete.
+
+    2. Some minor changes have been made to the quick look output formats.
+
+    3. A verbose and verify switch have been added to all the appropriate
+    tasks.
+
+     4. Daofind has been modifed so that the convolved image is automatically
+     up to date if any of the convolution kernel parameters have been
+     modified.
+
+    Davis, May 27, 1989
+
+apphot$
+    1. Add the verify switch to radprof and wphot.
+
+    2. Began separation of the scale and fwhmpsf parameter.
+       Scale was added to the apphot structure.
+
+    Davis, May 17, 1989
+
+apphot$
+    1. Fixed an error in the definition of the skyfile format in phot.hlp
+    and wphot.hlp. The are seven columns not five with the x and y position
+    in columns 1 and 2.
+
+    2. Added the verify switch to the center, fitsky, fitpsf and polyphot tasks.
+
+    Davis, Mar 20, 1989
+
+apphot$
+    1. Modified the prompts in datapars.par, centerpars.par, fitskypars.par
+    and photpars.par.
+
+    2. Added a confirm switch to the phot task.
+
+    Davis, Mar 15, 1989
+
+apphot$
+    1. Changed the interactive setup routine in daofind so that the radial
+    profile is centered before the interactive setup menu is entered.
+
+    2. A confirm switch has been added to the daofind task so that in batch
+    mode (the default) the user can check/confirm/modify the critical
+    task parameters. A similar 'v' for verify key has been added to 
+    the list of interactive menu setup commands.
+
+    Davis, Mar 14, 1989
+
+apphot$
+    1. Edited the daofind parameter file to make the prompts more illuminating.
+
+    2. Changed all the daofind subdirectory procedure names beginning with
+    ap to ap_. This continues the apphot cleanup begun in January.
+
+    3. Fixed a bug in the interactive daofind code. If no convolution image
+    was opened daofind was trying to delete a nonexistent image at 
+    task termination.
+
+    Davis, Mar 13, 1989
+
+apphot$apselect/
+    I changed all the apselect subdirectory procedure names to begin with
+    ap_. This continues the cleanup begun in January. Moved the apkeysdef.h
+    file into the aplib subdirectory with all the other .h files.
+
+    1. Davis, Mar 3, 1989
+
+apphot$
+    I changed all the .keys and .skeys file extensions to .key extensions.
+    This removes a problem with installations which do a strip operation.
+
+    Davis, Feb 3, 1989
+
+apphot$apyfit.x
+    I fixed a potential problem in polyphot. If a user specified a concave
+    polygon and the image line intersected the polygon exactly on a vertex
+    polyphot might not be able to tell whether a line segment was inside
+    or outside the polygon, causing a error in the total flux computation.
+    The affected routine was ap_yclip in apyfit.x
+
+    1. Davis, Jan 30, 1989
+
+apphot$
+    All the tasks doing interactive setup using a radial profile now
+    center the profile before plotting. This facilitates marking the full
+    width half maximum of the psf on the plot.
+
+    Davis, Jan 23, 1989
+
+apphot
+    1. Davis, Jan 21, 1989
+    Began cleanup of file and procedure names. All file names now begin with
+    ap. All procedure names begin with ap. Eventually I will clean up
+    the ap to ap_ convention. The subdirectories polyphot and polymark
+    have been completely overhauled. Note caution about updates is in order.
+
+apphot
+    1. Davis, Nov 11, 1988
+    Removed a call to imparse in apimroot.x and a call to iki_parse in
+    apoutname.x. The calls were changed to imgimage.
+
+apphot
+    1. Davis, Nov 3, 1988
+    Daofind was outputing an incorrect magnitude estimate due to an indexing
+    problem. The correct stellar position was being output.
+
+apphot
+    1. Davis, Oct 27, 1988
+    The :aperts coomand in qphot.keys, phot.keys and wphot.keys was changed
+    to the correct :apertures command. The corresponding help pages were
+    also modified.
+
+apphot
+    1. Davis, Oct 4, 1988
+    The statement z = z + p[4] was out of order in the routine cdgauss1d
+    in cgauss1d.x. The evaluation of the derivative with respect to sigma
+    was in error. This bug would not be noticed in the apphot code as 
+    sigma was being held constant whenever this routine was called.
+
+apphot
+    1. Davis, Sept 12, 1988
+    The APPHOT package was installed in the apphot subdirectory of the
+    digiphot package.
+
+apphot
+    1. Davis, Aug 15, 1988
+    If the i key (interactive setup option) was used after the first object
+    record was written to the database file then the changed parameters
+    were not being updated in the database file. The : commands were
+    being updated correctly. This problem has been fixed in all the
+    interactive tasks.
+
+apphot
+    1. Davis, Aug 18, 1988
+    Apselect will now accept a list of text files as input. 
+
+apphot
+    1. Davis, Aug 16, 1988
+    The apphot tasks now save the apertures string as well as the list
+    of apertures. The phot, qphot and wphot phot tasks will noe accept
+    a ranges syntax of the form ap1:apn:apstep. This syntax can be
+    mixed with the former syntax. In addition it is know possible to read
+    the apertures from a text file.
+
+apphot
+    1. Davis, Aug 11, 1988
+    Fixed a bug in the angle computation for the elliptical Gaussian fitting
+    routine in fitpsf. Positive angles from 0 to 90 were correct, the
+    rest were being forced to be positive.
+
+    2. It is now possible to change the image, coordinate file and output
+    file name from apphot interactive mode.
+
+apphot
+    1. Changed the maximum number of apertures from 15 to 100.
+    2. Changed apwparam to allocate astring of SZ_LINE long.
+
+    Davis, Aug 4, 1988
+
+apphot
+    1. Fixed a bug in polyget.x. The program was hanging in batch mode when
+    one tried to read a polygons file created by the imtool cursor readback
+    facility. I removed an incorrectly placed next statement.
+
+    Davis, Jul 29, 1988
+
+apphot
+    1. Added id strings to all the parameter files which request
+    algorithm names etc.
+
+    Davis, Jun 1, 1988
+
+apphot
+    1. I fixed a potentially serious problem in the way daofind handles
+    out of bounds regions. Daofind was accessing an out of bounds array
+    which accasionally would fail with divide by zeros NaNs etc.
+    The positions of stars near the edge of the image could be affected.
+
+    Davis, Apr29, 1988
+
+apphot$
+    1. Added a new parameter threshold and changed old parameter threshold
+    to cthreshold.
+
+    2. Daofind now reads the datapars file. It can now work on both emission
+    and absorption features.
+
+    3. Cleaned up the output and integrated with rest of apphot.
+
+    Davis, Apr22, 1988
+
+apphot$
+    1. Removed redundant MISC string definitions.
+
+    2. Added the DATAMIN and DATAMAX parameters required by daophot. This
+    required changes to the apphot structure, the get and put pars routines
+    and the set and stat calls.
+
+    Davis, Apr12, 1988
+
+apphot$
+    1. Added correct error code handling for the case where cbox <= 0.0
+    or dannulus = 0.0. The correct action but incorrect error code was
+    being returned.
+
+    2. Fixed the same bug in the code for fitpsf.
+
+    Davis, Apr4, 1988
+
+apphot$
+    1. Fixed a bug in decoding the apertures string. If a nonsensical
+    apertures string was given then the apertures could be decoded into
+    some strange number.
+
+    Davis, Apr4, 1988
+
+apphot$apselect.x
+    1. I fixed a bug in the apselect task which occurred when the user
+    requested all the output fields with the * command and the output
+    records contained array valued fields. The select buffer
+    was being allocated space equal to the number of unique keys, not
+    space for the total number of elements causing memory overflow
+    problems.
+
+    Davis, Apr1, 1988
+
+apphot$
+    1. Added a needed gdeactivate command to i setup key menus when they
+    terminate prematurely. Otherwise the terminal is left in graphics
+    mode.
+
+    2. A bug in the batch mode of running apphot tasks occurred if a single
+    output file was specified and there were no stars in the first file.
+    The header could be written several times and cause and error in apselect.
+
+    Davis, Mar31, 1988
+
+apphot$fitpsf/
+    1. I changed the initial guess for the sigma to be the fwhmpsf instead
+    of a small fraction of the fitting box as before. This affects both the
+    radial Gaussian and the elliptical Gaussian.
+
+    Davis, Mar15,1988
+
+apphot$
+    1. Floating divide by 0 errors were occurring in daofind when the threshold
+    was set to zero. These were arising in two different places. The
+    magnitude estimate is based on a ratio with respect to threshold
+    and the sharpness computation can blow up when the peak pixel is zero.
+
+    2. I have added a warning message to aptime.x, appadu.x and aprdnoise.x
+    so that they will print an error message if the header parameter
+    keyword cannot be found in the image header.
+
+    Davis, Mar8,1988
+
+apphot$
+    The graphics and image device opens have been moved outside of the
+    image loop in interactive mode.
+
+    Davis, Feb23,1988
+
+apphot$
+    1. All the next now print out a short help page at startup time if they
+    are run in interactive mode.
+
+    2. I changed the task termination sequence.  q from inside the cursor
+    loop calls up a verification sequence, return goes back into the cursor
+    loop, n exits the cursor loop and asks for the next image, q quits the
+    task and w quits the task and writes to the pset parameter files.
+
+    3. I have added the bell character to the end of all warning messages.
+    More specific error messages were added to tell people that they are
+    at the end of a coordinate lists etc.
+
+    Davis, Feb18,1988
+
+apphot$
+    I switched the exposure and itime parameters from the photpars and
+    polypars psets to the datapars pset where they more properly belong.
+
+    Davis, Feb9, 1988
+
+apphot$
+    If salgorithm = constant then the algorithm which computes the magnitude
+    errors will try to use the value of the sigma parameter to estimate the
+    random noise inside the aperture. If sigma is INDEFR it will use only the
+    poisson statistics of the star.
+
+    Davis, Feb 6, 1988
+
+apphot$
+    Moved the pfeature parameter from centerpars and placed it in datapars
+    where it logically belongs.
+
+    Corrected a radprof error in which the extracted pixel array was being
+    call out of bounds even when it wasn't.
+
+    Polyphot was centering on the cursor position even when no polygon
+    had been defined.
+
+    Davis, Feb 5, 1988
+
+apphot$radprof/,apphot$apselect/
+    Fixed a minor bug in apselect. If string parameters were exactly equal
+    to their formatted lengths then a single extra character would get
+    printed at the end of each selected field. This happened for example
+    when the photometry parameter was out of bounds.
+
+    In the radprof task the sky subtracted sums were being printed out
+    instead of the total sums. The mangnitudes were being computed
+    correctly.
+
+    Davis, Feb 2, 1988
+
+apphot$apselect/
+    Made extensive changes to the keyword and units string maintenance
+    facilities, mostly to make the package easier to maintain.
+
+    Changed the pfeature keyword to emission which makes more sense.
+
+    Davis, Jan 25, 1988
+
+apphot$t_apselect.x
+    Corrected a bug in the apselect program in which the package would
+    crash if the fields string was set to NULL. I included a check for
+    the null string in the t_apselect.x procedure.
+
+    Davis, Jan 20, 1988
+
+apphot$
+    I made the task lintran part of the apphot package. This allows the
+    user to manipulate the coordinate lists.
+
+    Davis, Jan 20, 1988
+
+apphot$polyphot/pyprint
+    I corrected an error in the format string for the polyphot magnitude
+    error which was shifting the number over 2 columns.
+
+    Davis, Jan 9, 1988
+
+apphot$daofind/apfind.x
+    A bug in the way daofind computed the convolution kernel for very
+    small kernels was discovered and corrected. The kernel is supposed to
+    be defined for all pixels < 2.0 pixels from the center. For small
+    kernels these elements were being left at zero. IN most cases this
+    causes no problems except for the fact that the sharpness parameter
+    was lower than seen from daofind and that the nomalization for the
+    magnitudes is different. Workarounds are to increase nsigma from the
+    default of 1.5.
+
+    Davis, Jan 6, 1988
+
+apphot$polyphot/polyfit.x
+    The itime normalization was not working correctly in the polyphot
+    task. The time was being picked up correctly but the zero-point
+    correction was not being made to the magnitude.
+
+    Davis, Dec 31, 1987
+
+apphot$polyphot/pybphot.x
+    Davis, Dec 30, 1987
+    I fixed a bug in the polyphot batch mode processing routine. An
+    "illegal file descriptor" error was occurring when polyphot was run
+    in batch mode with a null coordinate file list and a polygons list.
+
+apphot$
+    I continued the clean up of apphot output files. Some of these
+    bugs could cause problems for potential users of apselect.
+    Changed the units string for CERROR, SERROR, PERROR and RERROR to
+    "cerrors", "serrors", "rerrors" and "perrors" from "cerror",
+    "serror", "perror" and "rerror" respectively to make things consistent
+    with the other tasks.
+
+    I changed to polyphot units string for ZMAGNITUDE and EXPOSURE to
+    "zeropoint" and "keyword" respectively for consistency with the phot
+    bug.
+
+    Fixed a bug in the polyphot output file where a # was missing in front
+    of the line beginning with XCENTER.
+
+    Fixed a bug in the output of fitpsf with function = radgauss where
+    the SIGMA keyword was used for two different quantities and only the
+    first one was being output.
+
+    I changed the order of the output table headers from for example
+    #N#N#N #U#U#U and #F#F#F to #N#U#F #N#U#F and #N#U#F. I rechecked 
+    apselect on all this.
+
+    Davis, Dec 22, 1987
+
+apphot$
+    I added a comment about the definition of box in the fitpsf parameter
+    file.
+
+    Changed the output format of the center task slightly. The units for
+    HOST are now "computer". Similarly the units string for GAIN and
+    CCDREAD are now "keyword" and "keyword". These changes will affect
+    all tasks in the apphot package which use the datapars parameter set.
+
+    Changed the units string for SALGORITHM to "algorithm". I also corrected
+    an error in the COORDS keyword by changing it from CCORDS to COORDS.
+    I added an s to the ERROR units string, changing it from error to
+    errors.
+
+    I corrected a bug in the output file for the wphot task. The record
+    names, units and formats were not being written to the output file.
+    The problem was that the task name in the batch program had not
+    been changed from ophot to wphot. See also that the task statement
+    was incorrect.
+
+    Davis, Dec 21, 1987
+
+apphot$
+    I changed the default mode for the binary version of the  plotfile from
+    NEW_FILE to append. This avoids annoying cannot open plotfile
+    information when phot is run many times. The user must be aware
+    however that very long plot files can be generated. The affected
+    tasks are center, fitsky, phot, wphot, and radprof.
+
+    Davis, Dec 21, 1987
+
+apphot$apselect/apselect.x
+    I installed the new apselect in apphot. In the process I fixed the last
+    memory allocation bug which only showed up in the output of the radprof
+    program where the records were unusually long.
+
+    Davis, Dec 21, 1987
+
+apphot$radprof/apprprof.x
+    I fixed some minor bugs in the output format of radprof which were
+    causing apselect errors. First the records PRADIUS, INTENSITY, INTENSITY
+    should read PRADIUS, INTENSITY and TINTENSITY. The total intensity
+    record was never being read. I added a trailing slash at the end of the
+    magnitude record to indicate that the record continued on to include
+    the radial profile. If the radial profile was long > 20 records a
+    segmentation violation would occur as the program was not reallocating
+    extra memory correctly.
+
+    Davis, Dec 21, 1987
+
+apphot$radprof/aprpinit.x
+    Radprof was not reading multiple appertures from the photpars parameter
+    file correctly. The problem was that the napert and weight arguments
+    were reversed in the call to ap_photsetup making napert always equal
+    to  1.
+
+    Davis, Dec 15, 1987
+
+apphot$apselect/
+    Array subscripts in the apselect task were not being handled correctly
+    on the sun machines. The problem was in the call to the stridx routine.
+    A character constant was being placed in the first argument which is
+    interpreted as an integer. This wa ok on Vax machines with their reverse
+    byte order but did not work on the Suns. I set up some character
+    constants and taht removed the problem.
+
+    Arrays and array elements were not always being handled correctly by the
+    expression parser. In fact arrays are curently illegal in expression.
+    The program will now abort with a more informative error message if
+    it detects an array in an expression. Array elements are permitted
+    however.
+
+    I added  some missing mfree statements which were causing random
+    segmentation violation errors from time to time.
+
+    Finally I made some changes for the sake of efficiency. For example
+    I call the routine apchoose only once instead of once for each record
+    in the output file.
+
+    Davis, Dec 15, 1987
+
+apphot$apphot.hd
+    Changed the name of the wphot help page from ophot.hlp to wphot.hlp
+    and the same of the source code file from t_ophot.x to t_wphot.x.
+    Ophot was the historical name of this package.
+
+    Corrected an error in the installation guide instructions on installing
+    the help database. The help apphot command was not functioning
+    correctly. The problem was a missing apphot defintion infront of the
+    .men, .sys etc commands.
+    
+    Davis, Dec 15, 1987
+
+apphot$apimroot.x
+    Fixed a bug in the output file name generating code. If output = default
+    and the image name specification included an image section then apphot
+    tasks would try to create an output file name of the form .extension.
+    version. The left square brackett made the image name appear like a
+    directory to fio. I included code to strip the image section off the
+    image name before constructing the output file name. The image
+    section information is however preserved in the output file.
+
+    Davis, Dec 10, 1987
+
+---------------------------------------------------------------------------
+
+    October 27, 1987 Alpha Test Version Released
+
+--------------------------------------------------------------------------
+.endhelp
diff --git a/noao/digiphot/apphot/aplib/apairmass.x b/noao/digiphot/apphot/aplib/apairmass.x
new file mode 100644
index 00000000..3dcb9cdf
--- /dev/null
+++ b/noao/digiphot/apphot/aplib/apairmass.x
@@ -0,0 +1,36 @@
+include <imhdr.h>
+include "../lib/apphot.h"
+
+# AP_AIRMASS -  Procedure to determine the image airmass.
+
+procedure ap_airmass (im, ap)
+
+pointer	im		# pointer to IRAF image
+pointer	ap		# pointer to apphot structure
+
+pointer	sp, key
+real	xair
+real	imgetr(), apstatr()
+
+begin
+	call smark (sp)
+	call salloc (key, SZ_FNAME, TY_CHAR)
+	call apstats (ap, AIRMASS, Memc[key], SZ_FNAME)
+	if (Memc[key] == EOS)
+	    xair = apstatr (ap, XAIRMASS)
+	else {
+	    iferr { 
+	        xair = imgetr (im, Memc[key])
+	    } then {
+		xair = apstatr (ap, XAIRMASS)
+		call eprintf ("Warning: Image %s  Keyword: %s not found\n")
+		    call pargstr (IM_HDRFILE(im))
+		    call pargstr (Memc[key])
+	    }
+	}
+	if (IS_INDEFR(xair) || xair <= 0.0)
+	    call apsetr (ap, XAIRMASS, INDEFR)
+	else
+	    call apsetr (ap, XAIRMASS, xair)
+	call sfree (sp)
+end
diff --git a/noao/digiphot/apphot/aplib/apapcolon.x b/noao/digiphot/apphot/aplib/apapcolon.x
new file mode 100644
index 00000000..1a906345
--- /dev/null
+++ b/noao/digiphot/apphot/aplib/apapcolon.x
@@ -0,0 +1,353 @@
+include <error.h>
+include "../lib/apphot.h"
+
+# AP_APCOLON -- Process colon commands for setting the top level apphot package
+# parameters.
+
+procedure ap_apcolon (ap, im, cl, out, stid, ltid, cmdstr, newimage,
+	newcenterbuf, newcenter, newskybuf, newsky, newbuf, newfit)
+
+pointer	ap			# pointer to the apphot structure
+pointer	im			# pointer to the iraf image
+int	cl			# coordinate file descriptor
+int	out			# output file descriptor
+int	stid			# output file sequence number
+int	ltid			# coordinate file sequence number
+char	cmdstr[ARB]		# command string
+int	newimage		# new image ?
+int	newcenterbuf, newcenter	# new centering parameters ?
+int	newskybuf, newsky	# new sky fitting parameters ?
+int	newbuf, newfit		# new photometry parameters ?
+
+bool	bval
+int	ncmd, ip
+pointer	sp, cmd, str
+real	rval
+
+bool	streq(), itob()
+int	strdic(), nscan(), btoi(), apstati(), ctowrd(), open()
+pointer	immap()
+real	apstatr()
+errchk	immmap, open
+
+begin
+	# Allocate working space.
+	call smark (sp)
+	call salloc (cmd, SZ_LINE, TY_CHAR)
+	call salloc (str, SZ_LINE, TY_CHAR)
+
+	# Get the command.
+	ip = 1
+	call sscan (cmdstr)
+	call gargwrd (Memc[cmd], SZ_LINE)
+	if (Memc[cmd] == EOS) {
+	    call sfree (sp)
+	    return
+	}
+
+	# Process the command.
+	ncmd = strdic (Memc[cmd], Memc[cmd], SZ_LINE, APCMDS)
+	switch (ncmd) {
+
+	case APCMD_FWHMPSF:
+	    call gargr (rval)
+	    if (nscan() == 1) {
+		call printf ("%s = %g %s\n")
+		    call pargstr (KY_FWHMPSF)
+		    call pargr (apstatr (ap, FWHMPSF))
+		    call pargstr (UN_ASCALEUNIT)
+	    } else {
+		call apsetr (ap, FWHMPSF, rval)
+		if (stid > 1)
+		    call ap_rparam (out, KY_FWHMPSF, rval, UN_ASCALEUNIT,
+			"full width half max of psf")
+		newcenterbuf = YES; newcenter = YES
+		newskybuf = YES; newsky = YES
+		newbuf = YES; newfit = YES
+	    }
+
+	case APCMD_SCALE:
+	    call gargr (rval)
+	    if (nscan () == 1) {
+		call printf ("%s = %g %s\n")
+		    call pargstr (KY_SCALE)
+		    call pargr (1.0 / apstatr (ap, SCALE))
+		    call pargstr (UN_AUNITS)
+	    } else if (rval > 0.0) {
+		call apsetr (ap, SCALE, (1.0 / rval))
+		if (stid > 1)
+		    call ap_rparam (out, KY_SCALE, (1.0 / rval), UN_AUNITS,
+			"scale in units / pixel")
+		newcenterbuf = YES; newcenter = YES
+		newskybuf = YES; newsky = YES
+		newbuf = YES; newfit = YES
+	    }
+
+	case APCMD_EMISSION:
+	    call gargb (bval)
+	    if (nscan() == 1) {
+		call printf ("%s = %b\n")
+		    call pargstr (KY_POSITIVE)
+		    call pargb (itob (apstati (ap, POSITIVE)))
+	    } else {
+		call apseti (ap, POSITIVE, btoi (bval))
+		if (stid > 1)
+		    call ap_bparam (out, KY_POSITIVE, bval, UN_ASWITCH,
+			"emission feature")
+		newcenterbuf = YES; newcenter = YES
+		newskybuf = YES; newsky = YES
+		newbuf = YES; newfit = YES
+	    }
+
+	case APCMD_FILTER:
+	    call gargstr (Memc[cmd], SZ_LINE)
+	    if (Memc[cmd] == EOS) {
+		call apstats (ap, FILTER, Memc[str], SZ_LINE)
+		call printf ("%s = %s\n")
+		    call pargstr (KY_FILTER)
+		    call pargstr (Memc[str])
+	    } else {
+	        if (ctowrd (Memc[cmd], ip, Memc[str], SZ_LINE) <= 0)
+		    Memc[str] = EOS
+		call apsets (ap, FILTER, Memc[str])
+		if (im != NULL)
+		    call ap_filter (im, ap)
+		if (stid > 1)
+		    call ap_sparam  (out, KY_FILTER, Memc[str], UN_AKEYWORD,
+			"filter keyword")
+	    }
+
+	case APCMD_FILTERID:
+	    call gargstr (Memc[cmd], SZ_LINE)
+	    if (Memc[cmd] == EOS) {
+		call apstats (ap, FILTERID, Memc[str], SZ_LINE)
+		call printf ("%s = %s\n")
+		    call pargstr (KY_FILTERID)
+		    call pargstr (Memc[str])
+	    } else {
+	        if (ctowrd (Memc[cmd], ip, Memc[str], SZ_LINE) <= 0)
+		    Memc[str] = EOS
+		call apsets (ap, FILTERID, Memc[str])
+	    }
+
+	case APCMD_OBSTIME:
+	    call gargstr (Memc[cmd], SZ_LINE)
+	    if (Memc[cmd] == EOS) {
+		call apstats (ap, OBSTIME, Memc[str], SZ_LINE)
+		call printf ("%s = %s\n")
+		    call pargstr (KY_OBSTIME)
+		    call pargstr (Memc[str])
+	    } else {
+	        if (ctowrd (Memc[cmd], ip, Memc[str], SZ_LINE) <= 0)
+		    Memc[str] = EOS
+		call apsets (ap, OBSTIME, Memc[str])
+		if (im != NULL)
+		    call ap_otime (im, ap)
+		if (stid > 1)
+		    call ap_sparam  (out, KY_OBSTIME, Memc[str], UN_AKEYWORD,
+			"obstime keyword")
+	    }
+
+	case APCMD_OTIME:
+	    call gargstr (Memc[cmd], SZ_LINE)
+	    if (Memc[cmd] == EOS) {
+		call apstats (ap, OTIME, Memc[str], SZ_LINE)
+		call printf ("%s = %s %s\n")
+		    call pargstr (KY_OTIME)
+		    call pargstr (Memc[str])
+		    call pargstr (UN_ATIMEUNIT)
+	    } else {
+	        if (ctowrd (Memc[cmd], ip, Memc[str], SZ_LINE) <= 0)
+		    Memc[str] = EOS
+		call apsets (ap, OTIME, Memc[str])
+	    }
+
+	case APCMD_AIRMASS:
+	    call gargstr (Memc[cmd], SZ_LINE)
+	    if (Memc[cmd] == EOS) {
+		call apstats (ap, AIRMASS, Memc[str], SZ_LINE)
+		call printf ("%s = %s\n")
+		    call pargstr (KY_AIRMASS)
+		    call pargstr (Memc[str])
+	    } else {
+	        if (ctowrd (Memc[cmd], ip, Memc[str], SZ_LINE) <= 0)
+		    Memc[str] = EOS
+		call apsets (ap, AIRMASS, Memc[str])
+		if (im != NULL)
+		    call ap_airmass (im, ap)
+		if (stid > 1)
+		    call ap_sparam  (out, KY_AIRMASS, Memc[str], UN_AKEYWORD,
+			"airmass keyword")
+	    }
+
+	case APCMD_XAIRMASS:
+	    call gargr (rval)
+	    if (nscan() == 1) {
+		call printf ("%s = %g %s\n")
+		    call pargstr (KY_XAIRMASS)
+		    call pargr (apstatr (ap, XAIRMASS))
+		    call pargstr (UN_ANUMBER)
+	    } else {
+		call apsetr (ap, XAIRMASS, rval)
+		#if (stid > 1)
+		    #call ap_rparam (out, KY_XAIRMASS, rval, UN_ANUMBER,
+			#"airmass")
+	    }
+
+	case APCMD_EXPOSURE:
+	    call gargstr (Memc[cmd], SZ_LINE)
+	    if (Memc[cmd] == EOS) {
+		call apstats (ap, EXPOSURE, Memc[str], SZ_LINE)
+		call printf ("%s = %s\n")
+		    call pargstr (KY_EXPOSURE)
+		    call pargstr (Memc[str])
+	    } else {
+	        if (ctowrd (Memc[cmd], ip, Memc[str], SZ_LINE) <= 0)
+		    Memc[str] = EOS
+		call apsets (ap, EXPOSURE, Memc[str])
+		if (im != NULL)
+		    call ap_itime (im, ap)
+		if (stid > 1)
+		    call ap_sparam  (out, KY_EXPOSURE, Memc[str], UN_AKEYWORD,
+			"exposure time keyword")
+		newfit = YES
+	    }
+
+	case APCMD_ITIME:
+	    call gargr (rval)
+	    if (nscan() == 1) {
+		call printf ("%s = %g %s\n")
+		    call pargstr (KY_ITIME)
+		    call pargr (apstatr (ap, ITIME))
+		    call pargstr (UN_ATIMEUNIT)
+	    } else {
+		call apsetr (ap, ITIME, rval)
+		#if (stid > 1)
+		    #call ap_rparam (out, KY_ITIME, rval, UN_ATIMEUNIT,
+			#"exposure time")
+		newfit = YES
+	    }
+
+	case APCMD_DATAMIN:
+	    call gargr (rval)
+	    if (nscan() == 1) {
+		call printf ("%s = %g %s\n")
+		    call pargstr (KY_DATAMIN)
+		    call pargr (apstatr (ap, DATAMIN))
+		    call pargstr (UN_ACOUNTS)
+	    } else {
+		call apsetr (ap, DATAMIN, rval)
+		if (stid > 1)
+		    call ap_rparam (out, KY_DATAMIN, rval, UN_ACOUNTS,
+			"minimim good data value")
+		newcenterbuf = YES; newcenter = YES
+		newskybuf = YES; newsky = YES
+		newbuf = YES; newfit = YES
+	    }
+
+	case APCMD_DATAMAX:
+	    call gargr (rval)
+	    if (nscan() == 1) {
+		call printf ("%s = %g %s\n")
+		    call pargstr (KY_DATAMAX)
+		    call pargr (apstatr (ap, DATAMAX))
+		    call pargstr (UN_ACOUNTS)
+	    } else {
+		call apsetr (ap, DATAMAX, rval)
+		if (stid > 1)
+		    call ap_rparam (out, KY_DATAMAX, rval, UN_ACOUNTS,
+			"maximum good data value")
+		newcenterbuf = YES; newcenter = YES
+		newskybuf = YES; newsky = YES
+		newbuf = YES; newfit = YES
+	    }
+
+	case APCMD_IMAGE:
+	    call gargwrd (Memc[cmd], SZ_LINE)
+	    call apstats (ap, IMNAME, Memc[str], SZ_FNAME)
+	    if (Memc[cmd] == EOS || streq (memc[cmd], Memc[str])) {
+		call printf ("%s: %s\n")
+		    call pargstr (KY_IMNAME)
+		    call pargstr (Memc[str])
+	    } else {
+		if (im != NULL) {
+		    call imunmap (im)
+		    im = NULL
+		}
+		iferr {
+		    im = immap (Memc[cmd], READ_ONLY, 0)
+		} then {
+		    call erract (EA_WARN)
+		    im = immap (Memc[str], READ_ONLY, 0)
+		} else {
+		    call apimkeys (ap, im, Memc[cmd])
+		    newimage = YES
+		    newcenterbuf = YES; newcenter = YES
+		    newskybuf = YES; newsky = YES
+		    newbuf = YES; newfit = YES
+		}
+	    }
+
+	case APCMD_COORDS:
+	    call gargwrd (Memc[cmd], SZ_LINE)
+	    call apstats (ap, CLNAME, Memc[str], SZ_FNAME)
+	    if (Memc[cmd] == EOS || streq (Memc[cmd], Memc[str])) {
+		call printf ("%s:  %s\n")
+		    call pargstr (KY_CLNAME)
+		    call pargstr (Memc[str])
+	    } else {
+		if (cl != NULL) {
+		    call close( cl)
+		    cl = NULL
+		}
+		iferr {
+		    cl = open (Memc[cmd], READ_ONLY, TEXT_FILE)
+		} then {
+		    cl = NULL
+		    call erract (EA_WARN)
+		    call apsets (ap, CLNAME, "")
+		    call apsets (ap, CLROOT, "")
+		    call printf ("Coordinate file is undefined.\n")
+		} else {
+		    call apsets (ap, CLNAME, Memc[cmd])
+		    call apfroot (Memc[cmd], Memc[str], SZ_FNAME)
+		    call apsets (ap, CLROOT, Memc[str])
+		    ltid = 0
+		}
+	    }
+
+	case APCMD_OUTPUT:
+	    call gargwrd (Memc[cmd], SZ_LINE)
+	    call apstats (ap, OUTNAME, Memc[str], SZ_FNAME)
+	    if (Memc[cmd] == EOS || streq (Memc[cmd], Memc[str])) {
+		call printf ("%s:  %s\n")
+		    call pargstr (KY_OUTNAME)
+		    call pargstr (Memc[str])
+	    } else {
+		if (out != NULL) {
+		    call close (out)
+		    out = NULL
+		    if (stid <= 1)
+		        call delete (Memc[str])
+		}
+		iferr {
+		    out = open (Memc[cmd], NEW_FILE, TEXT_FILE)
+		} then {
+		    call erract (EA_WARN)
+		    call printf ("Reopening output file: %s\n")
+			call pargstr (Memc[str])
+		    if (Memc[str] != EOS)
+		        out  = open (Memc[str], APPEND, TEXT_FILE)
+		    else
+			out = NULL
+		} else {
+		    call apsets (ap, OUTNAME, Memc[cmd])
+		    stid = 1
+		}
+	    }
+	default:
+	    call printf ("Unknown or ambiguous colon command\7\n")
+	}
+
+	call sfree (sp)
+end
diff --git a/noao/digiphot/apphot/aplib/aparrays.x b/noao/digiphot/apphot/aplib/aparrays.x
new file mode 100644
index 00000000..563608fd
--- /dev/null
+++ b/noao/digiphot/apphot/aplib/aparrays.x
@@ -0,0 +1,52 @@
+include "../lib/apphotdef.h"
+include "../lib/photdef.h"
+include "../lib/phot.h"
+
+# AP_ARRAYR -- Procedure to move apphot parameters stored as real arrays
+# into a user allocated array.
+
+procedure ap_arrayr (ap, param, array)
+
+pointer	ap		# pointer to apphot structure
+int	param		# parameter
+real	array[ARB]	# array
+
+pointer	phot
+
+begin
+	phot = AP_PPHOT(ap)
+	switch (param) {
+	case APERTS:
+	    call amovr (Memr[AP_APERTS(phot)], array, AP_NAPERTS(phot))
+	case MAGS:
+	    call amovr (Memr[AP_MAGS(phot)], array, AP_NAPERTS(phot))
+	case MAGERRS:
+	    call amovr (Memr[AP_MAGERRS(phot)], array, AP_NAPERTS(phot))
+	default:
+	    call error (0, "AP_ARRAYR: Unknown apphot real array")
+	}
+end
+
+
+# AP_ARRAYD -- Procedure to move apphot parameters stored as double arrays
+# into a user allocated array.
+
+procedure ap_arrayd (ap, param, array)
+
+pointer	ap		# pointer to apphot structure
+int	param		# parameter
+double	array[ARB]	# array
+
+pointer	phot
+
+begin
+	phot = AP_PPHOT(ap)
+	switch (param) {
+	case AREAS:
+	    call amovd (Memd[AP_AREA(phot)], array, AP_NAPERTS(phot))
+	case SUMS:
+	    call amovd (Memd[AP_SUMS(phot)], array, AP_NAPERTS(phot))
+	default:
+	    call error (0, "AP_ARRAYD: Unknown apphot double array")
+	}
+end
diff --git a/noao/digiphot/apphot/aplib/apfilter.x b/noao/digiphot/apphot/aplib/apfilter.x
new file mode 100644
index 00000000..b9bfcc9d
--- /dev/null
+++ b/noao/digiphot/apphot/aplib/apfilter.x
@@ -0,0 +1,41 @@
+include <imhdr.h>
+include "../lib/apphot.h"
+
+# AP_FILTER --  Procedure to set the image airmass.
+
+procedure ap_filter (im, ap)
+
+pointer	im		# pointer to IRAF image
+pointer	ap		# pointer to apphot structure
+
+pointer	sp, key, filt
+
+begin
+	call smark (sp)
+	call salloc (key, SZ_FNAME, TY_CHAR)
+	call salloc (filt, SZ_FNAME, TY_CHAR)
+
+	call apstats (ap, FILTER, Memc[key], SZ_FNAME)
+	Memc[filt] = EOS
+	if (Memc[key] == EOS)
+	    call apstats (ap, FILTERID, Memc[filt], SZ_FNAME)
+	else {
+	    iferr { 
+	        call imgstr (im, Memc[key], Memc[filt], SZ_FNAME)
+	    } then {
+	        call apstats (ap, FILTERID, Memc[filt], SZ_FNAME)
+		call eprintf ("Warning: Image %s  Keyword: %s not found\n")
+		    call pargstr (IM_HDRFILE(im))
+		    call pargstr (Memc[key])
+	    }
+	}
+
+	if (Memc[filt] == EOS) {
+	    call apsets (ap, FILTERID, "INDEF")
+	} else {
+	    call ap_rmwhite (Memc[filt], Memc[filt], SZ_FNAME)
+	    call apsets (ap, FILTERID, Memc[filt])
+	}
+
+	call sfree (sp)
+end
diff --git a/noao/digiphot/apphot/aplib/apfree.x b/noao/digiphot/apphot/aplib/apfree.x
new file mode 100644
index 00000000..30c6c396
--- /dev/null
+++ b/noao/digiphot/apphot/aplib/apfree.x
@@ -0,0 +1,25 @@
+include "../lib/apphotdef.h"
+
+# AP_NOISECLS -- Procedure to close up the noise structure and arrays.
+
+procedure ap_noisecls (ap)
+
+pointer ap		# pointer to apphot structure
+
+begin
+	if (AP_NOISE(ap) == NULL)
+	    return
+	call mfree (AP_NOISE(ap), TY_STRUCT)
+end
+
+
+# AP_DISPCLS -- Procedure to close up the dislay structure and arrays.
+
+procedure ap_dispcls (ap)
+
+pointer		ap		# pointer to the apphot structure
+
+begin
+	if (AP_PDISPLAY(ap) != NULL)
+	    call mfree (AP_PDISPLAY(ap), TY_STRUCT)
+end
diff --git a/noao/digiphot/apphot/aplib/apgaperts.x b/noao/digiphot/apphot/aplib/apgaperts.x
new file mode 100644
index 00000000..05558cc1
--- /dev/null
+++ b/noao/digiphot/apphot/aplib/apgaperts.x
@@ -0,0 +1,214 @@
+include <lexnum.h>
+include <ctype.h>
+
+# AP_GETAPERTS -- Procedure to extract real aperture values from a string
+
+int procedure ap_getaperts (str, aperts, max_naperts)
+
+char	str[ARB]		# string
+real	aperts[ARB]		# number of apertures
+int	max_naperts		# maximum number of apertures
+
+int	fd, naperts
+int	open(), ap_rdaperts(), ap_decaperts()
+errchk	open(), close()
+
+begin
+	naperts = 0
+
+	iferr {
+	    fd = open (str, READ_ONLY, TEXT_FILE)
+	    naperts = ap_rdaperts (fd, aperts, max_naperts)
+	    call close (fd)
+	} then {
+	    naperts = ap_decaperts (str, aperts, max_naperts)
+	}
+
+	return (naperts)
+end
+
+
+# AP_RDAPERTS -- Procedure to read out the apertures listed one per line
+# from a file.
+
+int procedure ap_rdaperts (fd, aperts, max_naperts)
+
+int	fd		# aperture list file descriptor
+real	aperts[ARB]	# list of apertures
+int	max_naperts	# maximum number of apertures
+
+int	naperts
+pointer	sp, line
+int	getline(), ap_decaperts()
+
+begin
+	call smark (sp)
+	call salloc (line, SZ_LINE, TY_CHAR)
+
+	naperts = 0
+	while (getline (fd, Memc[line]) != EOF && naperts < max_naperts) {
+	    naperts = naperts + ap_decaperts (Memc[line], aperts[1+naperts],
+	        max_naperts - naperts)
+	}
+
+	call sfree (sp)
+
+	return (naperts)
+end
+
+
+# AP_DECAPERTS -- Procedure to decode the aperture string.
+
+int procedure ap_decaperts (str, aperts, max_naperts)
+
+char	str[ARB]		# aperture string
+real	aperts[ARB]		# aperture array
+int	max_naperts		# maximum number of apertures
+
+char	outstr[SZ_LINE]
+int	naperts, ip, op, ndecode, nap
+real	apstart, apend, apstep
+bool	fp_equalr()
+int	gctor()
+
+begin
+	naperts = 0
+
+	for (ip = 1; str[ip] != EOS && naperts < max_naperts;) {
+
+	    apstart = 0.0
+	    apend = 0.0
+	    apstep = 0.0
+	    ndecode = 0
+
+	    # Skip past white space and commas.
+	    while (IS_WHITE(str[ip]))
+		ip = ip + 1
+	    if (str[ip] == ',')
+		ip = ip + 1
+
+	    # Get the number.
+	    op = 1
+	    while (IS_DIGIT(str[ip]) || str[ip] == '.') {
+		outstr[op] = str[ip]
+		ip = ip + 1
+		op = op + 1
+	    }
+	    outstr[op] = EOS
+
+	    # Decode the starting aperture.
+	    op = 1
+	    if (gctor (outstr, op, apstart) > 0) {
+	        apend = apstart
+	        ndecode = 1
+	    } else
+		apstart = 0.0
+
+	    # Skip past white space and commas.
+	    while (IS_WHITE(str[ip]))
+		ip = ip + 1
+	    if (str[ip] == ',')
+		ip = ip + 1
+
+	    # Get the ending aperture
+	    if (str[ip] == ':') {
+		ip = ip + 1
+
+		# Get the ending aperture.
+		op = 1
+		while (IS_DIGIT(str[ip]) || str[ip] == '.') {
+		    outstr[op] = str[ip]
+		    ip = ip + 1
+		    op = op + 1
+		}
+		outstr[op] = EOS
+
+	        # Decode the ending aperture.
+	        op = 1
+	        if (gctor (outstr, op, apend) > 0) {
+	            ndecode = 2
+	            apstep = apend - apstart
+		}
+	     }
+
+	    # Skip past white space and commas.
+	    while (IS_WHITE(str[ip]))
+		ip = ip + 1
+	    if (str[ip] == ',')
+		ip = ip + 1
+
+	    # Get the step size.
+	    if (str[ip] == ':') {
+		ip = ip + 1
+
+		# Get the step size.
+		op = 1
+		while (IS_DIGIT(str[ip]) || str[ip] == '.') {
+		    outstr[op] = str[ip]
+		    ip = ip + 1
+		    op = op + 1
+		}
+		outstr[op] = EOS
+
+		# Decode the step size.
+		op = 1
+		if (gctor (outstr, op, apstep) > 0) {
+		    if (fp_equalr (apstep, 0.0))
+			apstep = apend - apstart
+		    else
+			ndecode = (apend - apstart) / apstep + 1
+		    if (ndecode < 0) {
+			ndecode = -ndecode
+			apstep = - apstep
+		    }
+		}
+	    }
+
+	    # Negative apertures are not permitted.
+	    if (apstart <= 0.0 || apend <= 0.0)
+		break
+
+	    # Fill in the apertures.
+	    if (ndecode == 0) {
+		;
+	    } else if (ndecode == 1) {
+		naperts = naperts + 1
+		aperts[naperts] = apstart
+	    } else if (ndecode == 2) {
+		naperts = naperts + 1
+		aperts[naperts] = apstart
+		if (naperts >= max_naperts)
+		    break
+		naperts = naperts + 1
+		aperts[naperts] = apend
+	    } else {
+		for (nap = 1; nap <= ndecode && naperts < max_naperts;
+		    nap = nap + 1) {
+		    naperts = naperts + 1
+		    aperts[naperts] = apstart + (nap - 1) * apstep
+		}
+	    }
+	}
+
+	return (naperts)
+end
+
+
+# GCTOR -- Procedure to convert a character variable to a real number.
+# This routine is just an interface routine to the IRAF procedure gctod.
+
+int procedure gctor (str, ip, rval)
+
+char	str[ARB]	# string to be converted
+int	ip		# pointer to the string
+real	rval		# real value
+
+double	dval
+int	nchars
+int	gctod()
+
+begin
+	nchars = gctod (str, ip, dval)
+	rval = dval
+	return (nchars)
+end
diff --git a/noao/digiphot/apphot/aplib/apgqverify.x b/noao/digiphot/apphot/aplib/apgqverify.x
new file mode 100644
index 00000000..b7114e37
--- /dev/null
+++ b/noao/digiphot/apphot/aplib/apgqverify.x
@@ -0,0 +1,68 @@
+include <ttyset.h>
+include <fset.h>
+
+define	QUERY "[Hit return to continue, n next image, q quit, w quit and  save parameters]"
+
+# APGQVERIFY -- Print a message in the status line asking the user if they
+# really want to quit, returning YES if they really want to quit, NO otherwise.
+
+int procedure apgqverify (task, ap, ch)
+
+char	task[ARB]	# name of the apphot task
+pointer	ap		# pointer to apphot structure
+int	ch		# character keystroke command
+
+pointer	tty
+int	getci(), strmatch()
+pointer	ttyodes()
+
+begin
+	tty = ttyodes ("terminal")
+	call ttyclearln (STDOUT, tty)
+	call ttyso (STDOUT, tty, YES)
+
+	call printf (QUERY)
+	call flush (STDOUT)
+	call fseti (STDIN, F_RAW, YES)
+	if (getci (STDIN, ch) == EOF)
+	    ;
+	call fseti (STDIN, F_RAW, NO)
+	call ttyso (STDOUT, tty, NO)
+	call ttyclearln (STDOUT, tty)
+	call printf ("\n")
+	call flush (STDOUT)
+
+	call ttycdes (tty)
+
+	if (ch == 'q') {
+	    return (YES)
+	} else if (ch == 'w') {
+	    if (strmatch ("^center", task) > 0) {
+	        call ap_pcpars (ap)
+	    } else if (strmatch ("^fitsky", task) > 0) {
+		call ap_pspars (ap)
+	    } else if (strmatch ("^phot", task) > 0) {
+		call ap_ppars (ap)
+	    } else if (strmatch ("^wphot", task) > 0) {
+		call ap_wpars (ap)
+	    } else if (strmatch ("^qphot", task) > 0) {
+		call ap_qppars (ap)
+	    } else if (strmatch ("^polyphot", task) > 0) {
+		call ap_pypars (ap)
+	    } else if (strmatch ("^radprof", task) > 0) {
+		call ap_rpars (ap)
+	    } else if (strmatch ("^fitpsf", task) > 0) {
+		call ap_ppfpars (ap)
+	    } else if (strmatch ("^daofind", task) > 0) {
+		call ap_fdpars (ap)
+	    } else if (strmatch ("^polymark", task) > 0) {
+		;
+	    }
+	    return (YES)
+	} else if (ch == 'n') {
+	    return (YES)
+	} else {
+	    return (NO)
+	}
+
+end
diff --git a/noao/digiphot/apphot/aplib/apgsvw.x b/noao/digiphot/apphot/aplib/apgsvw.x
new file mode 100644
index 00000000..00f35e90
--- /dev/null
+++ b/noao/digiphot/apphot/aplib/apgsvw.x
@@ -0,0 +1,162 @@
+# Copyright(c) 1986 Association of Universities for Research in Astronomy Inc.
+
+include <imio.h>
+include <imhdr.h>
+include <math.h>
+
+# AP_GSWV -- Set the data window and viewport for the image display.
+
+procedure ap_gswv (id, image, im, max_nframes)
+
+pointer	id			# pointer to the image display graphics stream
+char	image			# the input image name
+pointer	im			# pointer to the input image
+int	max_nframes		# the maximum number of display frames
+
+real	vx1, vx2, vy1, vy2
+
+begin
+	if (id == NULL)
+	    return
+	call ap_gsview (image, im, max_nframes, vx1, vx2, vy1, vy2)
+	call gsview (id, vx1, vx2, vy1, vy2)
+	call gswind (id, 1.0, real (IM_LEN(im,1)), 1.0, real (IM_LEN(im,2)))
+end
+
+
+# AP_GSVIEW -- Map the viewport and window of the image display.
+
+procedure ap_gsview (image, im, max_nframes, vx1, vx2, vy1, vy2)
+
+char	image			# the input image name
+pointer	im			# pointer to the input image
+int	max_nframes		# the maximum number of display frames
+real	vx1, vx2, vy1, vy2	# the output viewport
+
+int	i, frame, wcs_status, dim1, dim2, step1, step2
+pointer	sp, rimname, frimage, frimname, frim, iw
+real	x1, x2, y1, y2, fx1, fx2, fy1, fy2, junkx, junky
+bool	streq()
+pointer	imd_mapframe(), iw_open()
+
+begin
+	# Allocate some memory.
+	call smark (sp)
+	call salloc (rimname, SZ_FNAME, TY_CHAR)
+	call salloc (frimage, SZ_FNAME, TY_CHAR)
+	call salloc (frimname, SZ_FNAME, TY_CHAR)
+
+	# Get the root image name.
+	call imgimage (image, Memc[rimname], SZ_FNAME)
+
+	# Loop through the defined image frames searching for the one
+	# which has the image loaded.
+
+	frame = 0
+	do i = 1, max_nframes {
+	    frim = imd_mapframe (i, READ_ONLY, NO)
+	    iw = iw_open (frim, i, Memc[frimage], SZ_FNAME, wcs_status)
+	    call imgimage (Memc[frimage], Memc[frimname], SZ_FNAME)
+	    if (streq (Memc[rimname], Memc[frimname])) {
+		frame = i
+		break
+	    } else {
+	        call iw_close (iw)
+	        call imunmap (frim)
+	    }
+	}
+
+	# Default to current frame if the image has not been displayes?
+	if (frame == 0) {
+	    call eprintf ("Warning: image %s is not loaded in the display\n")
+		call pargstr (Memc[rimname])
+	    vx1 = 0.0
+	    vx2 = 1.0
+	    vy1 = 0.0
+	    vy2 = 1.0
+	    call sfree (sp)
+	    return
+	}
+
+	# Find the beginning and end points of the requested image section.
+	# We already know at this point that the input logical image is
+	# 2-dimensional. However this 2-dimensional section may be part of
+	# n-dimensional image.
+
+	# X dimension.
+	dim1 = IM_VMAP(im,1)
+	step1 = IM_VSTEP(im,dim1)
+	if (step1 >= 0) {
+	    x1 = IM_VOFF(im,dim1) + 1
+	    x2 = x1 + IM_LEN(im,1) - 1
+	} else {
+	    x1 = IM_VOFF(im,dim1) - 1
+	    x2 = x1 - IM_LEN(im,1) + 1
+	}
+
+	# Y dimension.
+	dim2 = IM_VMAP(im,2)
+	step2 = IM_VSTEP(im,dim2)
+	if (step2 >= 0) {
+	    y1 = IM_VOFF(im,dim2) + 1
+	    y2 = y1 + IM_LEN(im,2) - 1
+	} else {
+	    y1 = IM_VOFF(im,dim2) - 1
+	    y2 = y1 - IM_LEN(im,2) + 1
+	}
+
+	# Get the frame buffer coordinates corresponding to the lower left
+	# and upper right corners of the image section.
+
+	call iw_im2fb (iw, x1, y1, fx1, fy1)
+	call iw_im2fb (iw, x2, y2, fx2, fy2)
+	if (fx1 > fx2) {
+	    junkx = fx1
+	    fx1 = fx2 
+	    fx2 = junkx
+	}
+	if (fy1 > fy2) {
+	    junky = fy1
+	    fy1 = fy2 
+	    fy2 = junky
+	}
+
+	# Check that some portion of the input image is in the display.
+	# If not select the default viewport and window coordinates.
+	if (fx1 > IM_LEN(frim,1) || fx2 < 1.0 || fy1 > IM_LEN(frim,2) ||
+	    fy2 < 1.0) {
+	    vx1 = 0.0
+	    vx2 = 1.0
+	    vy1 = 0.0
+	    vy2 = 1.0
+	    call iw_close (iw)
+	    call imunmap (frim)
+	    call sfree (sp)
+	    return
+	}
+
+	# Compute a new viewport and window for X.
+	if (fx1 >= 1.0)
+	    vx1 = max (0.0, min (1.0, (fx1 - 0.5) / IM_LEN(frim,1)))
+	else
+	    vx1 = 0.0
+	if (fx2 <= IM_LEN(frim,1))
+	    vx2 = max (0.0, min (1.0, (fx2 + 0.5) / IM_LEN(frim,1)))
+	else
+	    vx2 = 1.0
+
+	# Compute a new viewport and window for Y.
+	if (fy1 >= 1.0)
+	    vy1 = max (0.0, min (1.0, (fy1 - 0.5) / IM_LEN(frim,2)))
+	else
+	    vy1 = 0.0
+	if (fy2 <= IM_LEN(frim,2))
+	    vy2 = max (0.0, min (1.0, (fy2 + 0.5)  / IM_LEN(frim,2)))
+	else
+	    vy2 = 1.0
+
+	# Clean up.
+	call iw_close (iw)
+	call imunmap (frim)
+	call sfree (sp)
+end
diff --git a/noao/digiphot/apphot/aplib/apgtverify.x b/noao/digiphot/apphot/aplib/apgtverify.x
new file mode 100644
index 00000000..a2d8bed8
--- /dev/null
+++ b/noao/digiphot/apphot/aplib/apgtverify.x
@@ -0,0 +1,19 @@
+# APGTVERIFY -- Print a message in the status line asking the user if they
+# really want to quit, returning YES if they really want to quit, NO otherwise.
+
+int procedure apgtverify (ch)
+
+int	ch	# character keystroke command
+
+begin
+	if (ch == 'q') {
+	    return (YES)
+	} else if (ch == 'w') {
+	    return (YES)
+	} else if (ch == 'n') {
+	    return (NO)
+	} else {
+	    return (NO)
+	}
+
+end
diff --git a/noao/digiphot/apphot/aplib/apimbuf.x b/noao/digiphot/apphot/aplib/apimbuf.x
new file mode 100644
index 00000000..d600a15d
--- /dev/null
+++ b/noao/digiphot/apphot/aplib/apimbuf.x
@@ -0,0 +1,17 @@
+include "../lib/apphotdef.h"
+
+# AP_IMBUF -- Set the parameters for the image buffer.
+
+procedure ap_imbuf (ap, hwidth, sequential)
+
+pointer	ap		# pointer to the apphot structure
+int	hwidth		# halfwidth of the line buffer
+int	sequential	# optimize for sequntial i/o
+
+begin
+	AP_SEQUENTIAL(ap) = sequential
+	AP_HWIDTH(ap) = hwidth
+	if (AP_IMBUF(ap) != NULL)
+	    call mfree (AP_IMBUF(ap), TY_REAL)
+	AP_IMBUF(ap) = NULL
+end
diff --git a/noao/digiphot/apphot/aplib/apimkeys.x b/noao/digiphot/apphot/aplib/apimkeys.x
new file mode 100644
index 00000000..74105404
--- /dev/null
+++ b/noao/digiphot/apphot/aplib/apimkeys.x
@@ -0,0 +1,72 @@
+include "../lib/apphot.h"
+
+# APIMKEYS - Set the image name and keyword parameters after an image
+# is mapped.
+
+procedure apimkeys (ap, im, imname)
+
+pointer	ap			# pointer to the apphot structure
+pointer	im			# the image descriptor
+char	imname[ARB]		# the input image name
+
+pointer	sp, imroot, mw, ct
+int	apstati()
+pointer	mw_openim(), mw_sctran()
+errchk	mw_openim(), mw_sctran()
+
+begin
+	call smark (sp)
+	call salloc (imroot, SZ_FNAME, TY_CHAR)
+
+	# Set the image and root names.
+        call apsets (ap, IMNAME, imname)
+	call apimroot (imname, Memc[imroot], SZ_FNAME)
+	call apsets (ap, IMROOT, Memc[imroot])
+
+	# Set the wcs descriptors.
+	mw = apstati (ap, MW)
+	if (mw != NULL)
+	    call mw_close (mw)
+	iferr {
+	    mw = mw_openim (im) 
+	} then {
+	    call apseti (ap, MW, NULL)
+	    call apseti (ap, CTIN, NULL)
+	    call apseti (ap, CTOUT, NULL)
+	} else {
+	    call apseti (ap, MW, mw)
+	    switch (apstati (ap, WCSIN)) {
+	    case WCS_WORLD:
+		iferr (ct = mw_sctran (mw, "world", "logical", 03B))
+		    ct = NULL
+	    case WCS_PHYSICAL:
+		iferr (ct = mw_sctran (mw, "physical", "logical", 03B))
+		    ct = NULL
+	    case WCS_TV, WCS_LOGICAL:
+		ct = NULL
+	    default:
+		ct = NULL
+	    }
+	    call apseti (ap, CTIN, ct)
+	    switch (apstati (ap, WCSOUT)) {
+	    case WCS_PHYSICAL:
+		iferr (ct = mw_sctran (mw, "logical", "physical", 03B))
+		    ct = NULL
+	    case WCS_TV, WCS_LOGICAL:
+		ct = NULL
+	    default:
+		ct = NULL
+	    }
+	    call apseti (ap, CTOUT, ct)
+	}
+
+	# Set the keywords.
+	call ap_rdnoise (im, ap)
+        call ap_padu (im, ap)
+        call ap_itime (im, ap)
+        call ap_airmass (im, ap)
+        call ap_filter (im, ap)
+        call ap_otime (im, ap)
+
+	call sfree (sp)
+end
diff --git a/noao/digiphot/apphot/aplib/apinit.x b/noao/digiphot/apphot/aplib/apinit.x
new file mode 100644
index 00000000..19e87eee
--- /dev/null
+++ b/noao/digiphot/apphot/aplib/apinit.x
@@ -0,0 +1,106 @@
+include "../lib/apphotdef.h"
+include "../lib/apphot.h"
+include "../lib/noisedef.h"
+include "../lib/noise.h"
+include "../lib/displaydef.h"
+
+# AP_DEFSETUP -- Initialize the global apphot package parameters to their 
+# default values.
+
+procedure ap_defsetup (ap, fwhmpsf)
+
+pointer	ap			# pointer to the apphot package
+real	fwhmpsf			# the FWHM of the stellar images
+
+begin
+	# Initalize the file names.
+	AP_IMNAME(ap) = EOS
+	AP_IMROOT(ap) = EOS
+	AP_CLNAME(ap) = EOS
+	AP_CLROOT(ap) = EOS
+	AP_OUTNAME(ap) = EOS
+	AP_PLOTFILE(ap) = EOS
+	AP_OUTNAME(ap) = EOS
+
+	AP_WCSIN(ap) = WCS_LOGICAL
+	AP_WCSOUT(ap) = WCS_LOGICAL
+	AP_MW(ap) = NULL
+	AP_CTIN(ap) = NULL
+	AP_CTOUT(ap) = NULL
+
+	# Initialize the cursor positions.
+	AP_CWX(ap) = INDEFR
+	AP_CWY(ap) = INDEFR
+	AP_WX(ap) = INDEFR
+	AP_WY(ap) = INDEFR
+
+	# Set up the data characteristics.
+	AP_SCALE(ap) = DEF_SCALE
+	AP_FWHMPSF(ap) = fwhmpsf
+	AP_POSITIVE(ap) = DEF_POSITIVE
+	AP_DATAMIN(ap) = DEF_DATAMIN
+	AP_DATAMAX(ap) = DEF_DATAMAX
+
+	# Set up the image header keywords.
+	AP_EXPOSURE(ap) = EOS
+	AP_ITIME(ap) = DEF_ITIME
+	AP_FILTER(ap) = EOS
+	call strcpy (DEF_FILTERID, AP_FILTERID(ap), SZ_FNAME)
+	AP_AIRMASS(ap) = EOS
+	AP_XAIRMASS(ap) = DEF_XAIRMASS
+	AP_OBSTIME(ap) = EOS
+	call strcpy (DEF_OTIME, AP_OTIME(ap), SZ_FNAME)
+
+	# Set buffer parameters.
+	AP_SEQUENTIAL(ap) = NULL
+	AP_IMBUF(ap) = NULL
+	AP_HWIDTH(ap) = 0
+end
+
+
+# AP_NOISESETUP -- Procedure to intialize noise model parameters.
+
+procedure ap_noisesetup (ap, noise)
+
+pointer	ap	# pointer to apphot structure
+int	noise	# noise model
+
+pointer	nse
+
+begin
+	call malloc (AP_NOISE(ap), LEN_APNOISE, TY_STRUCT)
+	nse = AP_NOISE(ap)
+	AP_NOISEFUNCTION(nse) = noise
+	switch (noise) {
+	case AP_NCONSTANT:
+	    call strcpy ("constant", AP_NSTRING(nse), SZ_FNAME)
+	case AP_NPOISSON:
+	    call strcpy ("poisson", AP_NSTRING(nse), SZ_FNAME)
+	default:
+	    call strcpy ("poisson", AP_NSTRING(nse), SZ_FNAME)
+	}
+	AP_READNOISE(nse) = DEF_READNOISE
+	AP_SKYSIGMA(nse) = DEF_SKYSIGMA
+	AP_EPADU(nse) = DEF_EPADU
+	AP_GAIN(nse) = EOS
+	AP_CCDREAD(nse) = EOS
+end
+
+
+# AP_DISPSETUP -- Procedure to setup the display parameters.
+
+procedure ap_dispsetup (ap)
+
+pointer	ap		# pointer to apphot structure
+
+pointer	dsp
+
+begin
+	call malloc (AP_PDISPLAY(ap), LEN_DISPLAYSTRUCT, TY_STRUCT)
+	dsp = AP_PDISPLAY(ap)
+	AP_MKSKY(dsp) = DEF_MKSKY
+	AP_MKCENTER(dsp) = DEF_MKCENTER
+	AP_MKAPERT(dsp) = DEF_MKAPERT
+	AP_RADPLOTS(dsp) = DEF_RADPLOTS
+	AP_MKDETECTIONS(dsp) = DEF_MKDETECTIONS
+end
diff --git a/noao/digiphot/apphot/aplib/apinpars1.x b/noao/digiphot/apphot/aplib/apinpars1.x
new file mode 100644
index 00000000..cc332004
--- /dev/null
+++ b/noao/digiphot/apphot/aplib/apinpars1.x
@@ -0,0 +1,104 @@
+include "../lib/apphot.h"
+include "../lib/display.h"
+include "../lib/noise.h"
+include "../lib/find.h"
+
+# AP_GDAPARS-- Read in the data dependent parameters from the datapars file.
+
+procedure ap_gdapars (ap)
+
+pointer	ap			# pointer to the apphot structure
+
+int	noise
+pointer	sp, str, np
+bool	clgpsetb()
+int	strdic(), btoi()
+pointer	clopset()
+real	clgpsetr()
+
+begin
+	# Allocate workin space.
+	call smark (sp)
+	call salloc (str, SZ_LINE, TY_CHAR)
+
+	# Open the pset parameter file.
+	np = clopset ("datapars")
+
+	# Get the data dependent parameters.
+	call apsetr (ap, FWHMPSF, clgpsetr (np, "fwhmpsf"))
+	call apsetr (ap, SCALE, 1.0 / clgpsetr (np, "scale"))
+	call apseti (ap, POSITIVE, btoi (clgpsetb (np, "emission")))
+	call apsetr (ap, DATAMIN, clgpsetr (np, "datamin"))
+	call apsetr (ap, DATAMAX, clgpsetr (np, "datamax"))
+	call apsetr (ap, SKYSIGMA, clgpsetr (np, "sigma"))
+
+	# Get the noise function parameters.
+	call clgpset (np, "noise", Memc[str], SZ_LINE)
+	noise = strdic (Memc[str], Memc[str], SZ_LINE, NFUNCS)
+	call apsets (ap, NSTRING, Memc[str])
+	call apseti (ap, NOISEFUNCTION, noise)
+	call clgpset (np, "gain", Memc[str], SZ_LINE)
+	call apsets (ap, GAIN, Memc[str])
+	call apsetr (ap, EPADU, clgpsetr (np, "epadu"))
+	call clgpset (np, "ccdread", Memc[str], SZ_LINE)
+	call apsets (ap, CCDREAD, Memc[str])
+	call apsetr (ap, READNOISE, clgpsetr (np, "readnoise"))
+
+	# Get the image header parameters.
+	call clgpset (np, "exposure", Memc[str], SZ_LINE)
+	call apsets (ap, EXPOSURE, Memc[str])
+	call apsetr (ap, ITIME, clgpsetr (np, "itime"))
+	call clgpset (np, "airmass", Memc[str], SZ_LINE)
+	call apsets (ap, AIRMASS, Memc[str])
+	call apsetr (ap, XAIRMASS, clgpsetr (np, "xairmass"))
+	call clgpset (np, "filter", Memc[str], SZ_LINE)
+	call apsets (ap, FILTER, Memc[str])
+	call clgpset (np, "ifilter", Memc[str], SZ_LINE)
+	call apsets (ap, FILTERID, Memc[str])
+	call clgpset (np, "obstime", Memc[str], SZ_LINE)
+	call apsets (ap, OBSTIME, Memc[str])
+	call clgpset (np, "otime", Memc[str], SZ_LINE)
+	call apsets (ap, OTIME, Memc[str])
+
+	# Close the parameter set files.
+	call clcpset (np)
+
+	call sfree (sp)
+end
+
+
+# AP_GFIPARS -- Read in the object finding parametes from the findpars
+# parameter file.
+
+procedure ap_gfipars (ap)
+
+pointer	ap			# pointer to the apphot structure
+
+pointer	pp
+bool	clgpsetb()
+int	btoi()
+pointer	clopset()
+real	clgpsetr()
+
+begin
+	# Open the pset parameter file.
+	pp = clopset ("findpars")
+
+	# Get the kernel statistics.
+	call apsetr (ap, NSIGMA, clgpsetr (pp, "nsigma"))
+	call apsetr (ap, RATIO, clgpsetr (pp, "ratio"))
+	call apsetr (ap, THETA, clgpsetr (pp, "theta"))
+
+	# Get the image detection characteristics.
+	call apsetr (ap, THRESHOLD, clgpsetr (pp, "threshold"))
+	call apsetr (ap, SHARPLO, clgpsetr (pp, "sharplo"))
+	call apsetr (ap, SHARPHI, clgpsetr (pp, "sharphi"))
+	call apsetr (ap, ROUNDLO, clgpsetr (pp, "roundlo"))
+	call apsetr (ap, ROUNDHI, clgpsetr (pp, "roundhi"))
+
+	# Set the marking parameter.
+	call apseti (ap, MKDETECTIONS, btoi (clgpsetb (pp, "mkdetections")))
+
+	# Close the parameter set file.
+	call clcpset (pp)
+end
diff --git a/noao/digiphot/apphot/aplib/apinpars2.x b/noao/digiphot/apphot/aplib/apinpars2.x
new file mode 100644
index 00000000..ff9cf3eb
--- /dev/null
+++ b/noao/digiphot/apphot/aplib/apinpars2.x
@@ -0,0 +1,207 @@
+include "../lib/display.h"
+include "../lib/center.h"
+include "../lib/fitsky.h"
+include "../lib/phot.h"
+include "../lib/polyphot.h"
+
+# AP_GCEPARS -- Read in the centering algorithm parameters from the 
+# centerpars parameter file.
+
+procedure ap_gcepars (ap)
+
+pointer	ap			# pointer to the apphot structure
+
+int	function
+pointer	sp, str, pp
+bool	clgpsetb()
+int	strdic(), btoi(), clgpseti()
+pointer	clopset()
+real	clgpsetr()
+
+begin
+	call smark (sp)
+	call salloc (str, SZ_LINE, TY_CHAR)
+
+	# Open the pset parameter file.
+	pp = clopset ("centerpars")
+
+	# Get the centering parameters.
+	call clgpset (pp, "calgorithm", Memc[str], SZ_LINE)
+	function = strdic (Memc[str], Memc[str], SZ_LINE, CFUNCS)
+	call apsets (ap, CSTRING, Memc[str])
+	call apseti (ap, CENTERFUNCTION, function)
+	call apsetr (ap, CAPERT, clgpsetr (pp, "cbox") / 2.0)
+	call apsetr (ap, CTHRESHOLD, clgpsetr (pp, "cthreshold"))
+	call apsetr (ap, MINSNRATIO, clgpsetr (pp, "minsnratio"))
+	call apseti (ap, CMAXITER, clgpseti (pp, "cmaxiter"))
+	call apsetr (ap, MAXSHIFT, clgpsetr (pp, "maxshift"))
+	call apseti (ap, CLEAN, btoi (clgpsetb (pp, "clean")))
+	call apsetr (ap, RCLEAN, clgpsetr (pp, "rclean"))
+	call apsetr (ap, RCLIP, clgpsetr (pp, "rclip"))
+	call apsetr (ap, SIGMACLEAN, clgpsetr (pp, "kclean"))
+
+	call apseti (ap, MKCENTER, btoi (clgpsetb (pp, "mkcenter")))
+
+
+	# Close the parameter set file.
+	call clcpset (pp)
+
+	call sfree (sp)
+end
+
+
+# AP_GSAPARS -- Read in the sky fitting parameters from the fitskypars
+# parameter file.
+
+procedure ap_gsapars (ap)
+
+pointer	ap		# pointer to the apphot strucuture
+
+int	function
+pointer	sp, str, pp
+bool	clgpsetb()
+int	strdic(), clgpseti(), btoi()
+pointer	clopset()
+real	clgpsetr()
+
+begin
+	call smark (sp)
+	call salloc (str, SZ_LINE, TY_CHAR)
+
+	# Open the pset parameter file.
+	pp = clopset ("fitskypars")
+
+	# Get the sky fitting algorithm parameters.
+	call clgpset (pp, "salgorithm", Memc[str], SZ_LINE)
+	function = strdic (Memc[str], Memc[str], SZ_LINE, SFUNCS)
+	call apsets (ap, SSTRING, Memc[str])
+	call apseti (ap, SKYFUNCTION, function)
+	call apsetr (ap, SKY_BACKGROUND, clgpsetr (pp, "skyvalue"))
+	call apsetr (ap, ANNULUS, clgpsetr (pp, "annulus"))
+	call apsetr (ap, DANNULUS, clgpsetr (pp, "dannulus"))
+	call apsetr (ap, K1, clgpsetr (pp, "khist"))
+	call apsetr (ap, BINSIZE, clgpsetr (pp, "binsize"))
+	call apseti (ap, SMOOTH, btoi (clgpsetb (pp, "smooth")))
+	call apseti (ap, SMAXITER, clgpseti (pp, "smaxiter"))
+	call apsetr (ap, SLOCLIP, clgpsetr (pp, "sloclip"))
+	call apsetr (ap, SHICLIP, clgpsetr (pp, "shiclip"))
+	call apseti (ap, SNREJECT, clgpseti (pp, "snreject"))
+	call apsetr (ap, SLOREJECT, clgpsetr (pp, "sloreject"))
+	call apsetr (ap, SHIREJECT, clgpsetr (pp, "shireject"))
+	call apsetr (ap, RGROW, clgpsetr (pp, "rgrow"))
+
+	# Get the marking parameter.
+	call apseti (ap, MKSKY, btoi (clgpsetb (pp, "mksky")))
+
+	# Close the parameter set file.
+	call clcpset (pp)
+
+	call sfree (sp)
+end
+
+
+# AP_GPHPARS -- Get the photometry algorithm parameters from the photometry
+# file.
+
+procedure ap_gphars (ap)
+
+pointer	ap		# pointer to the apphot strucuture
+
+pointer	sp, str, pp
+bool	clgpsetb()
+int	btoi()
+pointer	clopset()
+real	clgpsetr()
+
+begin
+	call smark (sp)
+	call salloc (str, SZ_LINE, TY_CHAR)
+
+	# Open the pset parameter file.
+	pp = clopset ("photpars")
+
+	# Get the photometry parameters.
+	call clgpset (pp, "apertures", Memc[str], SZ_LINE)
+	call apsets (ap, APERTS, Memc[str])
+	call apsetr (ap, ZMAG, clgpsetr (pp, "zmag"))
+	call apseti (ap, MKAPERT, btoi (clgpsetb (pp, "mkapert")))
+	call apsets (ap, PWSTRING, "constant")
+	call apseti (ap, PWEIGHTS, AP_PWCONSTANT)
+
+	# Close the parameter set file.
+	call clcpset (pp)
+
+	call sfree (sp)
+end
+
+
+# AP_GPOPARS -- Get the polygonal aperture photometry parameters.
+
+procedure ap_gpopars (ap)
+
+pointer	ap		# pointer to the apphot strucuture
+
+pointer	sp, str, pp
+bool	clgpsetb()
+int	btoi()
+pointer	clopset()
+real	clgpsetr()
+
+begin
+	call smark (sp)
+	call salloc (str, SZ_LINE, TY_CHAR)
+
+	# Open the pset parameter file.
+	pp = clopset ("polypars")
+
+	# Get the parameters.
+	call apsetr (ap, PYZMAG, clgpsetr (pp, "zmag"))
+	call apseti (ap, MKPOLYGON, btoi (clgpsetb (pp, "mkpolygon")))
+
+	# Close the parameter set file.
+	call clcpset (pp)
+
+	call sfree (sp)
+end
+
+
+# AP_GWHPARS -- Get the photometry algorithm parameters from the photometry
+# file.
+
+procedure ap_gwhars (ap)
+
+pointer	ap		# pointer to the apphot strucuture
+
+int	weight
+pointer	sp, str, pp
+bool	clgpsetb()
+int	btoi(), strdic()
+pointer	clopset()
+real	clgpsetr()
+
+begin
+	call smark (sp)
+	call salloc (str, SZ_LINE, TY_CHAR)
+
+	# Open the pset parameter file.
+	pp = clopset ("photpars")
+
+	# Get the photometry parameters.
+	call clgpset (pp, "apertures", Memc[str], SZ_LINE)
+	call apsets (ap, APERTS, Memc[str])
+	call apsetr (ap, ZMAG, clgpsetr (pp, "zmag"))
+	call apseti (ap, MKAPERT, btoi (clgpsetb (pp, "mkapert")))
+	call apsets (ap, PWSTRING, "constant")
+	call apseti (ap, PWEIGHTS, AP_PWCONSTANT)
+
+	# Get the major parameters.
+	call clgpset (pp, "weighting", Memc[str], SZ_LINE)
+	weight = strdic (Memc[str], Memc[str], SZ_LINE, PWFUNCS)
+	call apsets (ap, PWSTRING, Memc[str])
+	call apseti (ap, PWEIGHTS, weight)
+
+	# Close the parameter set file.
+	call clcpset (pp)
+
+	call sfree (sp)
+end
diff --git a/noao/digiphot/apphot/aplib/apitime.x b/noao/digiphot/apphot/aplib/apitime.x
new file mode 100644
index 00000000..c01dfc9e
--- /dev/null
+++ b/noao/digiphot/apphot/aplib/apitime.x
@@ -0,0 +1,36 @@
+include <imhdr.h>
+include "../lib/apphot.h"
+
+# AP_ITIME -  Procedure to set the image exposure time .
+
+procedure ap_itime (im, ap)
+
+pointer	im		# pointer to IRAF image
+pointer	ap		# pointer to apphot structure
+
+pointer	sp, key
+real	itime
+real	imgetr(), apstatr()
+
+begin
+	call smark (sp)
+	call salloc (key, SZ_FNAME, TY_CHAR)
+	call apstats (ap, EXPOSURE, Memc[key], SZ_FNAME)
+	if (Memc[key] == EOS)
+	    itime = apstatr (ap, ITIME)
+	else {
+	    iferr { 
+	        itime = imgetr (im, Memc[key])
+	    } then {
+		itime = apstatr (ap, ITIME)
+		call eprintf ("Warning: Image %s  Keyword: %s not found\n")
+		    call pargstr (IM_HDRFILE(im))
+		    call pargstr (Memc[key])
+	    }
+	}
+	if (IS_INDEFR(itime) || itime <= 0.0)
+	    call apsetr (ap, ITIME, 1.0)
+	else
+	    call apsetr (ap, ITIME, itime)
+	call sfree (sp)
+end
diff --git a/noao/digiphot/apphot/aplib/apmark1.x b/noao/digiphot/apphot/aplib/apmark1.x
new file mode 100644
index 00000000..1982a679
--- /dev/null
+++ b/noao/digiphot/apphot/aplib/apmark1.x
@@ -0,0 +1,270 @@
+include <gset.h>
+include "../lib/apphot.h"
+include "../lib/center.h"
+include "../lib/fitsky.h"
+include "../lib/phot.h"
+include "../lib/polyphot.h"
+include "../lib/radprof.h"
+
+# APMARK -- Procedure to mark center, fitsky and phot parameters on the display.
+
+procedure apmark (ap, id, mkcenter, mksky, mkapert)
+
+pointer	ap		# apphot pointer
+pointer	id		# pointer to image display stream
+int	mkcenter	# mark the computed center
+int	mksky		# mark the sky annulus
+int	mkapert		# mark the aperture(s)
+
+int	i, marktype
+pointer	sp, temp
+real	inner_sky, outer_sky, apert
+int	apstati(), gstati()
+real	apstatr()
+errchk	greactivate, gdeactivate, gamove, gadraw, gmark
+
+begin
+	if (id == NULL)
+	    return
+	if (mkcenter == NO && mksky == NO && mkapert == NO)
+	    return
+	iferr {
+	    call greactivate (id, 0)
+	} then {
+	    return
+	}
+
+	marktype = gstati (id, G_PMLTYPE)
+
+	# Mark the center and shift on the display.
+	if (mkcenter == YES) {
+	    iferr {
+	        call gseti (id, G_PMLTYPE, GL_SOLID)
+	        call gamove (id, (apstatr (ap, XCENTER) - apstatr (ap, XSHIFT)),
+		    (apstatr (ap, YCENTER) - apstatr (ap, YSHIFT)))
+	        call gadraw (id, apstatr (ap, XCENTER), apstatr (ap, YCENTER))
+	        call gmark (id, apstatr (ap, XCENTER), apstatr (ap, YCENTER),
+		    GM_PLUS, -2.0, -2.0)
+	    } then
+		;
+	}
+
+	# Draw the sky annuli on the display.
+	if (mksky == YES) {
+	    iferr {
+	        call gseti (id, G_PMLTYPE, GL_DASHED)
+	        call gmark (id, apstatr (ap, SXCUR), apstatr (ap, SYCUR),
+		    GM_PLUS, -2.0, -2.0)
+	        inner_sky = 2.0 * apstatr (ap, SCALE) * apstatr (ap, ANNULUS)
+	        call gmark (id, apstatr (ap, SXCUR), apstatr (ap, SYCUR),
+		    GM_CIRCLE, -inner_sky, -inner_sky)
+	        outer_sky = 2.0 * apstatr (ap, SCALE) * (apstatr (ap,
+		    ANNULUS) + apstatr (ap, DANNULUS))
+	        call gmark (id, apstatr (ap, SXCUR), apstatr (ap, SYCUR),
+		    GM_CIRCLE, -outer_sky, -outer_sky)
+	    } then
+		;
+	}
+
+	# Draw the apertures on the display.
+	if (mkapert == YES) {
+	    iferr {
+		call smark (sp)
+	        call salloc (temp, apstati (ap, NAPERTS), TY_REAL)
+	        call ap_arrayr (ap, APERTS, Memr[temp])
+	        call gseti (id, G_PMLTYPE, GL_DASHED)
+	        call gmark (id, apstatr (ap, PXCUR), apstatr (ap, PYCUR),
+		    GM_PLUS, -2.0, -2.0)
+	        do i = 1, apstati (ap, NAPERTS) {
+		    apert = 2.0 * apstatr (ap, SCALE) * Memr[temp+i-1]
+		    call gmark (id, apstatr (ap, PXCUR), apstatr (ap, PYCUR),
+		        GM_CIRCLE, -apert, -apert)
+	        }
+	        call sfree (sp)
+	    } then 
+		call sfree (sp)
+	}
+
+	# Restore the mark type.
+	call gseti (id, G_PMLTYPE, marktype)
+
+	iferr {
+	    call gdeactivate (id, 0)
+	} then
+	    return
+end
+
+# APPYMARK -- Procedure to mark center, fitsky and polyphot parameters on the
+# display.
+
+procedure appymark (ap, id, x, y, nver, mkcenter, mksky, mkpolygon)
+
+pointer	ap		# apphot pointer
+pointer	id		# pointer to image display stream
+real	x[ARB]		# coordinates of x vertices
+real	y[ARB]		# coordinates of y vertices
+int	nver		# number of vertices
+int	mkcenter	# mark the computed center
+int	mksky		# mark the sky annulus
+int	mkpolygon	# mark the aperture(s)
+
+int	marktype, linetype
+real	inner_sky, outer_sky
+int	gstati()
+real	apstatr()
+errchk	greactivate, gdeactivate, gamove, gadraw, gmark, gline
+
+begin
+	if (id == NULL)
+	    return
+	if (mkcenter == NO && mksky == NO && mkpolygon == NO)
+	    return
+	iferr {
+	    call greactivate (id, 0)
+	} then
+	    return
+
+	marktype = gstati (id, G_PMLTYPE)
+	linetype = gstati (id, G_PLTYPE)
+
+	if (mkcenter == YES) {
+	    iferr {
+	        call gseti (id, G_PMLTYPE, GL_SOLID)
+	        call gamove (id, (apstatr (ap, XCENTER) - apstatr (ap, XSHIFT)),
+		    (apstatr (ap, YCENTER) - apstatr (ap, YSHIFT)))
+	        call gadraw (id, apstatr (ap, XCENTER), apstatr (ap, YCENTER))
+	        call gmark (id, apstatr (ap, XCENTER), apstatr (ap, YCENTER),
+		    GM_PLUS, -2.0, -2.0)
+	    } then
+		;
+	}
+
+	if (mksky == YES) {
+	    iferr {
+	        call gseti (id, G_PMLTYPE, GL_DASHED)
+	        call gmark (id, apstatr (ap, SXCUR), apstatr (ap, SYCUR),
+		    GM_PLUS, -2.0, -2.0)
+	        inner_sky = 2.0 * apstatr (ap, SCALE) * apstatr (ap, ANNULUS)
+	        call gmark (id, apstatr (ap, SXCUR), apstatr (ap, SYCUR),
+		    GM_CIRCLE, -inner_sky, -inner_sky)
+	        outer_sky = 2.0 * apstatr (ap, SCALE) * (apstatr (ap,
+		    ANNULUS) + apstatr (ap, DANNULUS))
+	        call gmark (id, apstatr (ap, SXCUR), apstatr (ap, SYCUR),
+		    GM_CIRCLE, -outer_sky, -outer_sky)
+	    } then
+		;
+	}
+
+	if (mkpolygon == YES) {
+	    iferr {
+	        call gseti (id, G_PLTYPE, GL_DASHED)
+	        call gmark (id, apstatr (ap, PYCX), apstatr (ap, PYCY),
+		    GM_PLUS, -2.0, -2.0)
+	        call gpline (id, x, y, nver)
+	    } then
+		;
+	}
+
+	call gseti (id, G_PMLTYPE, marktype) 
+	call gseti (id, G_PLTYPE, linetype) 
+
+	iferr (call gdeactivate (id, 0))
+	    return
+end
+
+
+# APRMARK -- Procedure to mark center, fitsky and radprof parameters on the
+# display.
+
+procedure aprmark (ap, id, mkcenter, mksky, mkapert)
+
+pointer	ap		# apphot pointer
+pointer	id		# pointer to image display stream
+int	mkcenter	# mark the computed center
+int	mksky		# mark the sky annulus
+int	mkapert		# mark the aperture(s)
+
+int	i, marktype
+pointer	sp, temp
+real	inner_sky, outer_sky, apert, radius, xc, yc
+int	apstati(), gstati()
+real	apstatr()
+errchk	greactivate, gdeactivate, gamove, gadraw, gmark
+
+begin
+	if (id == NULL)
+	    return
+	if (mkcenter == NO && mksky == NO && mkapert == NO)
+	    return
+
+	iferr {
+	    call greactivate (id, 0)
+	} then
+	    return
+
+	marktype = gstati (id, G_PMLTYPE)
+
+	# Mark the center and shift on the display.
+	if (mkcenter == YES) {
+	    iferr {
+	        call gseti (id, G_PMLTYPE, GL_SOLID)
+	        call gamove (id, (apstatr (ap, XCENTER) - apstatr (ap, XSHIFT)),
+		    (apstatr (ap, YCENTER) - apstatr (ap, YSHIFT)))
+	        call gadraw (id, apstatr (ap, XCENTER), apstatr (ap, YCENTER))
+	        call gmark (id, apstatr (ap, XCENTER), apstatr (ap, YCENTER),
+		    GM_PLUS, -2.0, -2.0)
+		call gflush (id)
+	    } then
+		;
+	}
+
+	# Draw the sky annuli on the display.
+	if (mksky == YES) {
+	    iferr {
+	        call gseti (id, G_PMLTYPE, GL_DASHED)
+	        call gmark (id, apstatr (ap, SXCUR), apstatr (ap, SYCUR),
+		    GM_PLUS, -2.0, -2.0)
+	        inner_sky = 2.0 * apstatr (ap, SCALE) * apstatr (ap, ANNULUS)
+	        call gmark (id, apstatr (ap, SXCUR), apstatr (ap, SYCUR),
+		    GM_CIRCLE, -inner_sky, -inner_sky)
+	        outer_sky = 2.0 * apstatr (ap, SCALE) * (apstatr (ap,
+		    ANNULUS) + apstatr (ap, DANNULUS))
+	        call gmark (id, apstatr (ap, SXCUR), apstatr (ap, SYCUR),
+		    GM_CIRCLE, -outer_sky, -outer_sky)
+		call gflush (id)
+	    } then
+		;
+	}
+
+	# Draw the apertures on the display.
+	if (mkapert == YES) {
+	    iferr {
+	        call smark (sp)
+	        call salloc (temp, apstati (ap, NAPERTS), TY_REAL)
+	        call gseti (id, G_PMLTYPE, GL_DASHED)
+	        call gmark (id, apstatr (ap, XCENTER), apstatr (ap, YCENTER),
+		    GM_PLUS, -2.0, -2.0)
+	        call ap_arrayr (ap, APERTS, Memr[temp])
+	        do i = 1, apstati (ap, NAPERTS) {
+		    apert = 2.0 * apstatr (ap, SCALE) * Memr[temp+i-1]
+		    call gmark (id, apstatr (ap, XCENTER), apstatr (ap,
+		        YCENTER), GM_CIRCLE, -apert, -apert)
+	        }
+	        xc = apstatr (ap, XCENTER)
+	        yc = apstatr (ap, YCENTER)
+	        radius = apstatr (ap, SCALE) * apstatr (ap, RPRADIUS)
+	        call gamove (id, xc - radius, yc - radius)
+	        call gadraw (id, xc + radius, yc - radius)
+	        call gadraw (id, xc + radius, yc + radius)
+	        call gadraw (id, xc - radius, yc + radius)
+	        call gadraw (id, xc - radius, yc - radius)
+	        call sfree (sp)
+	    } then
+		call sfree (sp)
+	}
+
+	call gseti (id, G_PMLTYPE, marktype) 
+
+	iferr (call gdeactivate (id, 0))
+	    return
+end
diff --git a/noao/digiphot/apphot/aplib/apmark2.x b/noao/digiphot/apphot/aplib/apmark2.x
new file mode 100644
index 00000000..96896e56
--- /dev/null
+++ b/noao/digiphot/apphot/aplib/apmark2.x
@@ -0,0 +1,46 @@
+include <gset.h>
+include "../lib/apphot.h"
+include "../lib/fitpsf.h"
+
+
+# AP_PFMARK -- Procedure to mark the psf fitting box on the display.
+
+procedure appfmark (ap, id, mkbox)
+
+pointer	ap		# pointer to the apphot procedure
+pointer	id		# pointer to the display stream
+int	mkbox		# mark the psf fitting box
+
+int	marktype
+real	radius, xc, yc
+int	gstati()
+real	apstatr()
+errchk	greactivate, gdeactivate, gamove, gadraw
+
+begin
+	if (id == NULL)
+	    return
+	if (mkbox == NO)
+	    return
+
+	iferr (call greactivate (id, 0))
+	    return
+
+	marktype = gstati (id,G_PMLTYPE)
+	iferr {
+            call gseti (id, G_PMLTYPE, GL_DASHED)
+            xc = apstatr (ap, PFXCUR)
+	    yc = apstatr (ap, PFYCUR)
+	    radius = apstatr (ap, SCALE) * apstatr (ap, PSFAPERT)
+	    call gamove (id, xc - radius, yc - radius)
+	    call gadraw (id, xc + radius, yc - radius)
+	    call gadraw (id, xc + radius, yc + radius)
+	    call gadraw (id, xc - radius, yc + radius)
+	    call gadraw (id, xc - radius, yc - radius)
+	} then
+	    ;
+        call gseti (id, G_PMLTYPE, marktype)
+
+	iferr (call gdeactivate (id, 0))
+	    return
+end
diff --git a/noao/digiphot/apphot/aplib/apnew.x b/noao/digiphot/apphot/aplib/apnew.x
new file mode 100644
index 00000000..b5da6fc1
--- /dev/null
+++ b/noao/digiphot/apphot/aplib/apnew.x
@@ -0,0 +1,46 @@
+include "../lib/apphot.h"
+
+# APNEW -- Procedure to determine whether the current star is the same as
+# the previous star and/or whether the current star belongs to the coordinate
+# list or not.
+
+int procedure apnew (ap, wx, wy, xlist, ylist, newlist)
+
+pointer	ap		# pointer to the apphot structure
+real	wx		# x cursor coordinate
+real	wy		# y cursor coordinate
+real	xlist		# x list coordinate
+real	ylist		# y list coordinate
+int	newlist		# integer new list
+
+bool	fp_equalr()
+int	newobject
+real	deltaxy
+real	apstatr()
+
+begin
+	deltaxy = apstatr (ap, FWHMPSF) * apstatr (ap, SCALE)
+
+	if (newlist == NO) {
+            if (! fp_equalr (wx, apstatr (ap, WX)) || ! fp_equalr (wy,
+	            apstatr (ap, WY)))
+		newobject = YES
+	    else
+		newobject = NO
+	} else if ((abs (xlist - wx) <= deltaxy) &&
+	        (abs (ylist - wy) <= deltaxy)) {
+	    wx = xlist
+	    wy = ylist
+	    newobject = NO
+	} else if (fp_equalr (wx, apstatr (ap, WX)) && fp_equalr (wy,
+		apstatr (ap, WY))) {
+	    wx = xlist
+	    wy = ylist
+	    newobject = NO
+	} else {
+	    newlist = NO
+	    newobject = YES
+	}
+
+	return (newobject)
+end
diff --git a/noao/digiphot/apphot/aplib/apnscolon.x b/noao/digiphot/apphot/aplib/apnscolon.x
new file mode 100644
index 00000000..34bc43fc
--- /dev/null
+++ b/noao/digiphot/apphot/aplib/apnscolon.x
@@ -0,0 +1,165 @@
+include <error.h>
+include "../lib/noise.h"
+
+# AP_NSCOLON -- Procedure to process colon commands for setting
+# noise fitting parameters.
+
+procedure ap_nscolon (ap, im, out, stid, cmdstr, newcenterbuf,
+        newcenter, newskybuf, newsky, newbuf, newfit)
+
+pointer	ap			# pointer to the apphot structure
+pointer	im			# pointer to the iraf image
+int	out			# output file descriptor
+int	stid			# output file sequence number
+char	cmdstr[ARB]		# command string
+int	newcenterbuf, newcenter	# new centering parameters ?
+int	newskybuf, newsky	# new sky fitting parameters ?
+int	newbuf, newfit		# new photometry parameters ?
+
+int	ncmd, stat, ip
+pointer	sp, cmd, str
+real	rval
+int	strdic(), nscan(), ctowrd()
+real	apstatr()
+errchk	immmap
+
+begin
+	call smark (sp)
+	call salloc (cmd, SZ_LINE, TY_CHAR)
+	call salloc (str, SZ_LINE, TY_CHAR)
+
+	# Get the command.
+	ip = 1
+	call sscan (cmdstr)
+	call gargwrd (Memc[cmd], SZ_LINE)
+	if (Memc[cmd] == EOS) {
+	    call sfree (sp)
+	    return
+	}
+
+	# Process the command.
+	ncmd = strdic (Memc[cmd], Memc[cmd], SZ_LINE, NCMDS)
+	switch (ncmd) {
+
+	case NCMD_NOISE:
+	    call gargwrd (Memc[cmd], SZ_LINE)
+	    if (Memc[cmd] == EOS) {
+		call apstats (ap, NSTRING, Memc[str], SZ_FNAME)
+		call printf ("%s = %s %s\n")
+		    call pargstr (KY_NSTRING)
+		    call pargstr (Memc[str])
+		    call pargstr (UN_NMODEL)
+	    } else {
+		stat = strdic (Memc[cmd], Memc[cmd], SZ_LINE, NFUNCS)
+		if (stat > 0) {
+		    call apseti (ap, NOISEFUNCTION, stat)
+		    call apsets (ap, NSTRING, Memc[cmd])
+		    if (stid > 1)
+		        call ap_sparam (out, KY_NSTRING, Memc[cmd], UN_NMODEL,
+		            "noise model")
+		    newcenterbuf = YES; newcenter = YES
+		    newskybuf = YES; newsky = YES
+		    newbuf = YES; newfit = YES
+		}
+	    }
+
+	case NCMD_SIGMA:
+	    call gargr (rval)
+	    if (nscan() == 1) {
+		call printf ("%s = %g %s\n")
+		    call pargstr (KY_SKYSIGMA)
+		    call pargr (apstatr (ap, SKYSIGMA))
+		    call pargstr (UN_NCOUNTS)
+	    } else {
+		call apsetr (ap, SKYSIGMA, rval)
+		if (stid > 1)
+		    call ap_rparam (out, KY_SKYSIGMA, rval, UN_NCOUNTS,
+			"standard deviation of 1 pixel")
+		newcenterbuf = YES; newcenter = YES
+		newskybuf = YES; newsky = YES
+		newbuf = YES; newfit = YES
+	    }
+
+	case NCMD_EPADU:
+	    call gargr (rval)
+	    if (nscan() == 1) {
+		call printf ("%s = %g %s\n")
+		    call pargstr (KY_EPADU)
+		    call pargr (apstatr (ap, EPADU))
+		    call pargstr (UN_NEPADU)
+	    } else {
+		call apsetr (ap, EPADU, rval)
+		if (stid > 1)
+		    call ap_rparam (out, KY_EPADU, rval, UN_NEPADU,
+			"photons per adu")
+		newcenterbuf = YES; newcenter = YES
+		newskybuf = YES; newsky = YES
+		newbuf = YES; newfit = YES
+	    }
+
+	case NCMD_GAIN:
+	    call gargstr (Memc[cmd], SZ_LINE)
+	    if (Memc[cmd]  == EOS) {
+		call apstats (ap, GAIN, Memc[str], SZ_LINE)
+		call printf ("%s = %s\n")
+		    call pargstr (KY_GAIN)
+		    call pargstr (Memc[str])
+	    } else {
+	        if (ctowrd (Memc[cmd], ip, Memc[str], SZ_LINE) <= 0)
+		    Memc[str] = EOS
+		call apsets (ap, GAIN, Memc[str])
+		if (im != NULL)
+		    call ap_padu (im, ap)
+		if (stid > 1)
+		    call ap_sparam  (out, KY_GAIN, Memc[str], UN_NKEYWORD,
+			"gain keyword")
+		newcenterbuf = YES; newcenter = YES
+		newskybuf = YES; newsky = YES
+		newbuf = YES; newfit = YES
+	    }
+
+	case NCMD_CCDREAD:
+	    call gargstr (Memc[cmd], SZ_LINE)
+	    if (Memc[cmd] == EOS) {
+		call apstats (ap, CCDREAD, Memc[str], SZ_LINE)
+		call printf ("%s = %s\n")
+		    call pargstr (KY_CCDREAD)
+		    call pargstr (Memc[str])
+	    } else {
+	        if (ctowrd (Memc[cmd], ip, Memc[str], SZ_LINE) <= 0)
+		    Memc[str] = EOS
+		call apsets (ap, CCDREAD, Memc[str])
+		if (im != NULL)
+		    call ap_rdnoise (im, ap)
+		if (stid > 1)
+		    call ap_sparam  (out, KY_CCDREAD, Memc[str], UN_NKEYWORD,
+			"read noise keyword")
+		newcenterbuf = YES; newcenter = YES
+		newskybuf = YES; newsky = YES
+		newbuf = YES; newfit = YES
+	    }
+
+	case NCMD_READNOISE:
+	    call gargr (rval)
+	    if (nscan() == 1) {
+		call printf ("%s = %g %s\n")
+		    call pargstr (KY_READNOISE)
+		    call pargr (apstatr (ap, READNOISE))
+		    call pargstr (UN_NELECTRONS)
+	    } else {
+		call apsetr (ap, READNOISE, rval)
+		if (stid > 1)
+		    call ap_rparam (out, KY_READNOISE, rval, UN_NELECTRONS,
+			"readout noise")
+		newcenterbuf = YES; newcenter = YES
+		newskybuf = YES; newsky = YES
+		newbuf = YES; newfit = YES
+	    }
+
+
+	default:
+	    call printf ("Unknown or ambiguous colon command\7\n")
+	}
+
+	call sfree (sp)
+end
diff --git a/noao/digiphot/apphot/aplib/apnshow.x b/noao/digiphot/apphot/aplib/apnshow.x
new file mode 100644
index 00000000..a0a173a0
--- /dev/null
+++ b/noao/digiphot/apphot/aplib/apnshow.x
@@ -0,0 +1,118 @@
+include "../lib/apphot.h"
+include "../lib/noise.h"
+
+# AP_NSHOW -- Procedure to display the current data parameters.
+
+procedure ap_nshow (ap)
+
+pointer	ap	# pointer to the apphot structure
+
+pointer	sp, str1, str2
+bool	itob()
+int	apstati()
+real	apstatr()
+
+begin
+	call smark (sp)
+	call salloc (str1, SZ_LINE, TY_CHAR)
+	call salloc (str2, SZ_LINE, TY_CHAR)
+
+	# Set the object charactersitics.
+	call printf ("\nData Characteristics\n")
+	call apstats (ap, IMNAME, Memc[str1], SZ_FNAME)
+	call printf ("    %s: %s (%.2f, %.2f)   %s: %g\n")
+	    call pargstr (KY_IMNAME)
+	    call pargstr (Memc[str1])
+	    call pargr (apstatr (ap, CWX))
+	    call pargr (apstatr (ap, CWY))
+	    call pargstr (KY_SCALE)
+	    call pargr (1.0 / apstatr (ap, SCALE))
+
+	call apstats (ap, OUTNAME, Memc[str1], SZ_FNAME)
+	call printf ("    %s: %s")
+	    call pargstr (KY_OUTNAME)
+	    call pargstr (Memc[str1])
+
+	call apstats (ap, CLNAME, Memc[str1], SZ_FNAME)
+	call printf ("    %s: %s\n")
+	    call pargstr (KY_CLNAME)
+	    call pargstr (Memc[str1])
+
+	call printf ("    %s = %g %s    %s = %b\n")
+	    call pargstr (KY_FWHMPSF)
+	    call pargr (apstatr (ap, FWHMPSF))
+	    call pargstr (UN_ASCALEUNIT)
+	    call pargstr (KY_POSITIVE)
+	    call pargb (itob (apstati (ap, POSITIVE)))
+
+	call printf ("    %s = %g %s    %s = %g %s\n")
+	    call pargstr (KY_DATAMIN)
+	    call pargr (apstatr (ap, DATAMIN))
+	    call pargstr (UN_ACOUNTS)
+	    call pargstr (KY_DATAMAX)
+	    call pargr (apstatr (ap, DATAMAX))
+	    call pargstr (UN_ACOUNTS)
+
+	call apstats (ap, EXPOSURE, Memc[str1], SZ_FNAME)
+	call printf ("    %s = %s    %s = %g %s\n")
+	    call pargstr (KY_EXPOSURE)
+	    call pargstr (Memc[str1])
+	    call pargstr (KY_ITIME)
+	    call pargr (apstatr (ap, ITIME))
+	    call pargstr (UN_ATIMEUNIT)
+
+	# Set the filter ID.
+	call apstats (ap, FILTER, Memc[str1], SZ_FNAME)
+	call apstats (ap, FILTERID, Memc[str2], SZ_FNAME)
+	call printf ("    %s = %s    %s = %s\n")
+	    call pargstr (KY_FILTER)
+	    call pargstr (Memc[str1])
+	    call pargstr (KY_FILTERID)
+	    call pargstr (Memc[str2])
+
+	# Set the airmass.
+	call apstats (ap, AIRMASS, Memc[str1], SZ_FNAME)
+	call printf ("    %s = %s    %s = %g\n")
+	    call pargstr (KY_AIRMASS)
+	    call pargstr (Memc[str1])
+	    call pargstr (KY_XAIRMASS)
+	    call pargr (apstatr (ap, XAIRMASS))
+
+	# Set the time of observation.
+	call apstats (ap, OBSTIME, Memc[str1], SZ_FNAME)
+	call apstats (ap, OTIME, Memc[str2], SZ_FNAME)
+	call printf ("    %s = %s    %s = %s\n")
+	    call pargstr (KY_OBSTIME)
+	    call pargstr (Memc[str1])
+	    call pargstr (KY_OTIME)
+	    call pargstr (Memc[str2])
+
+	# Set the noise model.
+	call printf ("\nNoise Model\n")
+	call apstats (ap, NSTRING, Memc[str1], SZ_FNAME)
+	call printf ("    %s = %s  %s    %s = %g %s\n")
+	    call pargstr (KY_NSTRING)
+	    call pargstr (Memc[str1])
+	    call pargstr (UN_NMODEL)
+	    call pargstr (KY_SKYSIGMA)
+	    call pargr (apstatr (ap, SKYSIGMA))
+	    call pargstr (UN_NCOUNTS)
+
+	call apstats (ap, GAIN, Memc[str1], SZ_LINE)
+	call printf ("    %s = %s    %s = %g %s\n")
+	    call pargstr (KY_GAIN)
+	    call pargstr (Memc[str1])
+	    call pargstr (KY_EPADU)
+	    call pargr (apstatr (ap, EPADU))
+	    call pargstr (UN_NEPADU)
+
+	call apstats (ap, CCDREAD, Memc[str1], SZ_LINE)
+	call printf ("    %s = %s    %s = %g %s\n")
+	    call pargstr (KY_CCDREAD)
+	    call pargstr (Memc[str1])
+	    call pargstr (KY_READNOISE)
+	    call pargr (apstatr (ap, READNOISE))
+	    call pargstr (UN_NELECTRONS)
+
+	call sfree (sp)
+end
diff --git a/noao/digiphot/apphot/aplib/apotime.x b/noao/digiphot/apphot/aplib/apotime.x
new file mode 100644
index 00000000..2da01e3e
--- /dev/null
+++ b/noao/digiphot/apphot/aplib/apotime.x
@@ -0,0 +1,52 @@
+include <imhdr.h>
+include "../lib/apphot.h"
+
+# AP_OTIME --  Fetch the time or epoch of the observation from the image
+# header.
+
+procedure ap_otime (im, ap)
+
+pointer	im		# pointer to IRAF image
+pointer	ap		# pointer to apphot structure
+
+char	timechar
+int	index
+pointer	sp, key, otime
+bool	streq()
+int	strldx()
+
+begin
+	call smark (sp)
+	call salloc (key, SZ_FNAME, TY_CHAR)
+	call salloc (otime, SZ_FNAME, TY_CHAR)
+
+	call apstats (ap, OBSTIME, Memc[key], SZ_FNAME)
+	Memc[otime] = EOS
+	if (Memc[key] == EOS)
+	    call apstats (ap, OTIME, Memc[otime], SZ_FNAME)
+	else {
+	    iferr { 
+	        call imgstr (im, Memc[key], Memc[otime], SZ_FNAME)
+	    } then {
+	        call apstats (ap, OTIME, Memc[otime], SZ_FNAME)
+		call eprintf ("Warning: Image %s  Keyword: %s not found\n")
+		    call pargstr (IM_HDRFILE(im))
+		    call pargstr (Memc[key])
+	    }
+	}
+	if (Memc[otime] == EOS) {
+	    call apsets (ap, OTIME, "INDEF")
+	} else if (streq ("DATE-OBS", Memc[key]) || streq ("date-obs",
+	    Memc[key])) {
+	    timechar = 'T'
+	    index = strldx (timechar, Memc[otime])
+	    if (index > 0)
+		call apsets (ap, OTIME, Memc[otime+index])
+	    else
+	        call apsets (ap, OTIME, "INDEF")
+	} else {
+	    call apsets (ap, OTIME, Memc[otime])
+	}
+
+	call sfree (sp)
+end
diff --git a/noao/digiphot/apphot/aplib/apoutpars1.x b/noao/digiphot/apphot/aplib/apoutpars1.x
new file mode 100644
index 00000000..c4894bbb
--- /dev/null
+++ b/noao/digiphot/apphot/aplib/apoutpars1.x
@@ -0,0 +1,99 @@
+include "../lib/apphot.h"
+include "../lib/noise.h"
+include "../lib/display.h"
+include "../lib/find.h"
+
+
+# AP_DAPARS -- Procedure to write out the current DATAPARS parameters
+# to the current DATAPARS parameter file.
+
+procedure ap_dapars (ap)
+
+pointer	ap		# pointer to apphot structure
+
+pointer	sp, str, np
+bool	itob()
+int	apstati()
+pointer	clopset()
+real	apstatr()
+
+begin
+	# Open the parameter sets.
+	call smark (sp)
+	call salloc (str, SZ_LINE, TY_CHAR)
+
+	np = clopset ("datapars")
+
+	# Set the noise model.
+	call apstats (ap, NSTRING, Memc[str], SZ_FNAME)
+	call clppset (np, "noise", Memc[str])
+
+	# Get the rest of the data dependent parameters.
+	call clppsetr (np, "fwhmpsf", apstatr (ap, FWHMPSF))
+	call clppsetr (np, "scale", 1.0 / apstatr (ap, SCALE))
+	call clppsetb (np, "emission", itob (apstati (ap, POSITIVE)))
+	call clppsetr (np, "datamin", apstatr (ap, DATAMIN))
+	call clppsetr (np, "datamax", apstatr (ap, DATAMAX))
+
+	call clppsetr (np, "sigma", apstatr (ap, SKYSIGMA))
+	call apstats (ap, GAIN, Memc[str], SZ_LINE)
+	call clppset (np, "gain", Memc[str])
+	call clppsetr (np, "epadu", apstatr (ap, EPADU))
+	call apstats (ap, CCDREAD, Memc[str], SZ_LINE)
+	call clppset (np, "ccdread", Memc[str])
+	call clppsetr (np, "readnoise", apstatr (ap, READNOISE))
+
+	call apstats (ap, EXPOSURE, Memc[str], SZ_LINE)
+	call clppset (np, "exposure", Memc[str])
+	call clppsetr (np, "itime", apstatr (ap, ITIME))
+
+	call apstats (ap, AIRMASS, Memc[str], SZ_LINE)
+	call clppset (np, "airmass", Memc[str])
+	call clppsetr (np, "xairmass", apstatr (ap, XAIRMASS))
+
+	call apstats (ap, FILTER, Memc[str], SZ_LINE)
+	call clppset (np, "filter", Memc[str])
+	call apstats (ap, FILTERID, Memc[str], SZ_LINE)
+	call clppset (np, "ifilter", Memc[str])
+
+	call apstats (ap, OBSTIME, Memc[str], SZ_LINE)
+	call clppset (np, "obstime", Memc[str])
+	call apstats (ap, OTIME, Memc[str], SZ_LINE)
+	call clppset (np, "otime", Memc[str])
+
+	# Close the pset files.
+	call clcpset (np)
+	call sfree (sp)
+end
+
+
+# AP_FIPARS -- Procedure to write out the current FINDPARS parameters
+# to the current FINDPARS parameter file.
+
+procedure ap_fipars (ap)
+
+pointer	ap		# pointer to apphot structure
+
+pointer	pp
+bool	itob()
+int	apstati()
+pointer	clopset()
+real	apstatr()
+
+begin
+	pp = clopset ("findpars")
+
+	call clppsetr (pp, "nsigma", apstatr (ap, NSIGMA) )
+	call clppsetr (pp, "ratio", apstatr (ap, RATIO))
+	call clppsetr (pp, "theta", apstatr (ap, THETA))
+
+	call clppsetr (pp, "threshold", apstatr (ap, THRESHOLD))
+	call clppsetr (pp, "sharplo", apstatr (ap, SHARPLO))
+	call clppsetr (pp, "sharphi", apstatr (ap, SHARPHI))
+	call clppsetr (pp, "roundlo", apstatr (ap, ROUNDLO))
+	call clppsetr (pp, "roundhi", apstatr (ap, ROUNDHI))
+
+	call clppsetb (pp, "mkdetections", itob (apstati (ap, MKDETECTIONS)))
+
+	call clcpset (pp)
+end
diff --git a/noao/digiphot/apphot/aplib/apoutpars2.x b/noao/digiphot/apphot/aplib/apoutpars2.x
new file mode 100644
index 00000000..79b929c4
--- /dev/null
+++ b/noao/digiphot/apphot/aplib/apoutpars2.x
@@ -0,0 +1,146 @@
+include "../lib/display.h"
+include "../lib/center.h"
+include "../lib/fitsky.h"
+include "../lib/phot.h"
+include "../lib/polyphot.h"
+
+
+# AP_CEPARS -- Procedure to write out the current CENTERPARS parameters
+# to the current CENTERPARS parameter file.
+
+procedure ap_cepars (ap)
+
+pointer	ap		# pointer to apphot structure
+
+pointer	sp, str, cp
+bool	itob()
+int	apstati()
+pointer	clopset()
+real	apstatr()
+
+begin
+	# Open the parameter set.
+	call smark (sp)
+	call salloc (str, SZ_LINE, TY_CHAR)
+	cp = clopset ("centerpars")
+
+	# Write the centering parameters.
+	call apstats (ap, CSTRING, Memc[str], SZ_FNAME)
+	call clppset (cp, "calgorithm", Memc[str])
+	call clppsetr (cp, "cbox", 2.0 * apstatr (ap, CAPERT))
+	call clppsetr (cp, "cthreshold", apstatr (ap, CTHRESHOLD))
+	call clppsetr (cp, "minsnratio", apstatr (ap, MINSNRATIO))
+	call clppseti (cp, "cmaxiter", apstati (ap, CMAXITER))
+	call clppsetr (cp, "maxshift", apstatr (ap, MAXSHIFT))
+	call clppsetb (cp, "clean", itob (apstati (ap, CLEAN)))
+	call clppsetr (cp, "rclean", apstatr (ap, RCLEAN))
+	call clppsetr (cp, "rclip", apstatr (ap, RCLIP))
+	call clppsetr (cp, "kclean", apstatr (ap, SIGMACLEAN))
+	call clppsetb (cp, "mkcenter", itob (apstati (ap, MKCENTER)))
+
+	# Close the pset file.
+	call clcpset (cp)
+	call sfree (sp)
+end
+
+
+# AP_SAPARS -- Procedure to write out the current FITSKYPARS parameters
+# to the FITSKYPARS file.
+
+procedure ap_sapars (ap)
+
+pointer	ap		# pointer to apphot structure
+
+pointer	mp, str, sp
+bool	itob()
+int	apstati()
+pointer	clopset()
+real	apstatr()
+
+begin
+	# Open the parameter sets.
+	call smark (mp)
+	call salloc (str, SZ_LINE, TY_CHAR)
+	sp = clopset ("fitskypars")
+
+	# Set the sky fitting parameters.
+	call apstats (ap, SSTRING, Memc[str], SZ_FNAME)
+	call clppset (sp, "salgorithm", Memc[str])
+	call clppsetr (sp, "annulus", apstatr (ap, ANNULUS))
+	call clppsetr (sp, "dannulus", apstatr (ap, DANNULUS))
+	call clppsetr (sp, "skyvalue", apstatr (ap, SKY_BACKGROUND))
+	call clppsetr (sp, "khist", apstatr (ap, K1))
+	call clppsetr (sp, "binsize", apstatr (ap, BINSIZE))
+	call clppsetb (sp, "smooth", itob (apstati (ap, SMOOTH))) 
+	call clppsetr (sp, "sloclip", apstatr (ap, SLOCLIP))
+	call clppsetr (sp, "shiclip", apstatr (ap, SHICLIP))
+	call clppseti (sp, "smaxiter", apstati (ap, SMAXITER))
+	call clppseti (sp, "snreject", apstati (ap, SNREJECT))
+	call clppsetr (sp, "sloreject", apstatr (ap, SLOREJECT))
+	call clppsetr (sp, "shireject", apstatr (ap, SHIREJECT))
+	call clppsetr (sp, "rgrow", apstatr (ap, RGROW))
+	call clppsetb (sp, "mksky", itob (apstati (ap, MKSKY)))
+
+	# Close up the pset files.
+	call clcpset (sp)
+	call sfree (mp)
+end
+
+
+# AP_PHPARS -- Procedure to write out the PHOTPARS parameters to the
+# PHOTPARS task.
+
+procedure ap_phpars (ap)
+
+pointer	ap		# pointer to apphot structure
+
+pointer	mp, str, pp
+bool	itob()
+int	apstati()
+pointer	clopset()
+real	apstatr()
+
+begin
+	# Open the parameter set.
+	call smark (mp)
+	call salloc (str, SZ_LINE, TY_CHAR)
+	pp = clopset ("photpars")
+
+	# Set the photometry parameters.
+	call apstats (ap, APERTS, Memc[str], SZ_LINE)
+	call clppset (pp, "apertures", Memc[str])
+	call clppsetr (pp, "zmag", apstatr (ap, ZMAG))
+	call apstats (ap, PWSTRING, Memc[str], SZ_FNAME)
+	call clppset (pp, "weighting", Memc[str])
+	call clppsetb (pp, "mkapert", itob (apstati (ap, MKAPERT)))
+
+	# Close the pset file.
+	call clcpset (pp)
+	call sfree (mp)
+end
+
+
+# AP_POPARS -- Procedure to write the current POLYPARS parameters to the
+# current POLYPARS parameter file.
+
+procedure ap_popars (ap)
+
+pointer	ap		# pointer to apphot structure
+
+pointer	pp
+bool	itob()
+int	apstati()
+pointer	clopset()
+real	apstatr()
+
+begin
+	# Open the psets.
+	pp = clopset ("polypars")
+
+	# Set the photometry parameters.
+	call clppsetr (pp, "zmag", apstatr (ap, PYZMAG))
+	call clppsetb (pp, "mkpolygon", itob (apstati (ap, MKPOLYGON)))
+
+	# Close the pset files.
+	call clcpset (pp)
+end
diff --git a/noao/digiphot/apphot/aplib/appadu.x b/noao/digiphot/apphot/aplib/appadu.x
new file mode 100644
index 00000000..121decaf
--- /dev/null
+++ b/noao/digiphot/apphot/aplib/appadu.x
@@ -0,0 +1,37 @@
+include <imhdr.h>
+include "../lib/noise.h"
+
+# AP_PADU -- Procedure to set the gain parameter for the noise model
+# computation.
+
+procedure ap_padu (im, ap)
+
+pointer	im		# pointer to IRAF image
+pointer	ap		# pointer to apphot structure
+
+pointer	sp, key
+real	padu
+real	imgetr(), apstatr()
+
+begin
+	call smark (sp)
+	call salloc (key, SZ_FNAME, TY_CHAR)
+	call apstats (ap, GAIN, Memc[key], SZ_FNAME)
+	if (Memc[key] == EOS)
+	    padu = apstatr (ap, EPADU)
+	else {
+	    iferr {
+	        padu = imgetr (im, Memc[key])
+	    } then {
+		padu = apstatr (ap, EPADU)
+		call eprintf ("Warning: Image %s  Keyword %s not found.\n")
+		    call pargstr (IM_HDRFILE(im))
+		    call pargstr (Memc[key])
+	    }
+	}
+	if (IS_INDEFR(padu) || padu <= 0.0)
+	    call apsetr (ap, EPADU, 1.0)
+	else
+	    call apsetr (ap, EPADU, padu)
+	call sfree (sp)
+end
diff --git a/noao/digiphot/apphot/aplib/apqrad.x b/noao/digiphot/apphot/aplib/apqrad.x
new file mode 100644
index 00000000..6c035d7f
--- /dev/null
+++ b/noao/digiphot/apphot/aplib/apqrad.x
@@ -0,0 +1,119 @@
+include <mach.h>
+include "../lib/apphot.h"
+include "../lib/center.h"
+
+define	RADIUS	15.0
+define	CRADIUS	5
+
+# AP_QRAD -- Simple radial profile plotter.
+
+procedure ap_qrad (ap, im, wx, wy, gd)
+
+pointer	ap			# pointer to apphot structure
+pointer	im			# pointero to the IRAF image
+real	wx, wy			# cursor coordinates
+pointer	gd			# pointer to graphics stream
+
+real	gwx, gwy, xcenter, ycenter, xc, yc, radius, rmin, rmax, imin, imax
+real	u1, u2, v1, v2, x1, x2, y1, y2, xold, yold
+pointer	gt, sp, pix, coords, index, r, cmd
+int	maxpix, npix, nx, ny, wcs, key, niter
+
+real	apstatr()
+pointer	ap_gtinit()
+int	ap_skypix(), clgcur(), apstati()
+int	nscan(), scan()
+
+begin
+	# Check for open graphics stream.
+	if (gd == NULL)
+	    return
+	call greactivate (gd, 0)
+	call gclear (gd)
+	call gflush (gd)
+
+	# Get the radius of the extraction region.
+	call printf ("Half width of extraction box (%4.1f) pixels:")
+	    call pargr (RADIUS)
+	call flush (STDOUT)
+	if (scan () == EOF)
+	    radius = RADIUS
+	else {
+	    call gargr (radius)
+	    if (nscan () < 1)
+	        radius = RADIUS
+	}
+	maxpix = (2 * int (radius) + 1) ** 2
+	    
+	# Allocate temporary space.
+	call smark (sp)
+	call salloc (coords, maxpix, TY_INT)
+	call salloc (index, maxpix, TY_INT)
+	call salloc (pix, maxpix, TY_REAL)
+	call salloc (r, maxpix, TY_REAL)
+	call salloc (cmd, SZ_LINE, TY_CHAR)
+
+	# Fit the center using 3 iterations.
+	xold = wx
+	yold = wy
+	niter = 0
+	repeat {
+	    call ap_ictr (im, xold, yold, CRADIUS, apstati (ap,
+	        POSITIVE), xcenter, ycenter)
+	    niter = niter + 1
+	    if (abs (xcenter - xold) <= 1.0 && abs (ycenter - yold) <= 1.0)
+		break
+	    xold = xcenter
+	    yold = ycenter
+	} until (niter >= 3)
+
+	# Fetch the pixels for the radial profile.
+	npix = ap_skypix (im, xcenter, ycenter, 0.0, radius, Memr[pix],
+	    Memi[coords], xc, yc, nx, ny)
+	if (npix <= 0) {
+	    call gdeactivate (gd, 0)
+	    call sfree (sp)
+	    return
+	}
+	call ap_index (Memi[index], npix)
+
+
+	# Store old viewport and window coordinates.
+	call ggview (gd, u1, u2, v1, v2)
+	call ggwind (gd, x1, x2, y1, y2)
+
+	# Initialize the plot and store the viewport and window limits.
+	#call apstats (ap, IMNAME, Memc[cmd], SZ_FNAME)
+	call apstats (ap, IMROOT, Memc[cmd], SZ_FNAME)
+	call ap_ltov (im, xcenter, ycenter, xcenter, ycenter, 1)
+	gt = ap_gtinit (Memc[cmd], xcenter, ycenter)
+
+	# Compute the radius values.
+	call ap_xytor (Memi[coords], Memi[index], Memr[r], npix, xc, yc, nx)
+	call alimr (Memr[r], npix, rmin, rmax)
+	call alimr (Memr[pix], npix, imin, imax)
+
+	# Plot radial profiles.
+	call gclear (gd)
+	call ap_rset (gd, gt, 0.0, rmax, imin, imax, apstatr (ap, SCALE))
+	call ap_plotrad (gd, gt, Memr[r], Memr[pix], npix, "plus")
+
+	# Go into cursor mode.
+	call printf ("Waiting for cursor mode command: [:.help=help,q=quit]")
+	while (clgcur ("gcommands", gwx, gwy, wcs, key, Memc[cmd], SZ_LINE) !=
+	    EOF) {
+	    if (key == 'q')
+		break
+	    call printf (
+	        "Waiting for cursor mode command: [:.help=help,q=quit]")
+	}
+
+	# Restore old window and viewport coordinates.
+	call gsview (gd, u1, u2, v1, v2)
+	call gswind (gd, x1, x2, y1, y2)
+
+	# Free plots and working space.
+	call ap_gtfree (gt)
+	call sfree (sp)
+	call gdeactivate (gd, 0)
+end
diff --git a/noao/digiphot/apphot/aplib/aprcursor1.x b/noao/digiphot/apphot/aplib/aprcursor1.x
new file mode 100644
index 00000000..594cbbeb
--- /dev/null
+++ b/noao/digiphot/apphot/aplib/aprcursor1.x
@@ -0,0 +1,584 @@
+include "../lib/apphot.h"
+include "../lib/noise.h"
+include "../lib/center.h"
+include "../lib/fitsky.h"
+include "../lib/phot.h"
+
+
+# AP_CFWHMPSF -- Read the fwhmpsf from the radial profile plot.
+
+real procedure ap_cfwhmpsf (ap, gd, out, stid, rmin, rmax, imin, imax)
+
+pointer	ap		# pointer to the apphot structure
+pointer	gd		# pointer to the grapics stream
+int	out		# output file descriptor
+int	stid		# sequence number in output file
+real	rmin, rmax	# x axis limits
+real	imin, imax	# y axis limits
+
+int	wcs, key, stat
+pointer	sp, cmd
+real	scale, fwhmpsf, xjunk, yjunk
+int	clgcur()
+real	apstatr(), ap_vfwhmpsf()
+
+begin
+	call smark (sp)
+	call salloc (cmd, SZ_LINE, TY_CHAR)
+	scale = apstatr (ap, SCALE)
+
+	# Mark the FWHM of the PSF on the plot.
+	call printf ("Mark half-width half-maximum of the psf (%g) pixels:")
+	    call pargr (apstatr (ap, FWHMPSF) * scale / 2.0)
+	call gscur (gd, apstatr (ap, FWHMPSF) * scale / 2.0, (imin + imax) /
+	    2.0)
+	stat = clgcur ("gcommands", xjunk, yjunk, wcs, key, Memc[cmd], SZ_LINE)
+	if (stat == EOF || xjunk <= 0.0 || xjunk > rmax)
+	    fwhmpsf = apstatr (ap, FWHMPSF)
+	else
+	    fwhmpsf = 2.0 * xjunk / scale
+
+	# Verify the results.
+	call apsetr (ap, FWHMPSF, fwhmpsf)
+	fwhmpsf = ap_vfwhmpsf (ap)
+
+	# Save the results.
+	if (out != NULL && stid > 1)
+	    call ap_rparam (out, KY_FWHMPSF, fwhmpsf, UN_ASCALEUNIT,
+		"full width half maximum of the psf")
+
+	call sfree (sp)
+
+	return (fwhmpsf)
+end
+
+
+# AP_CDATAMIN -- Read the good data minimum off the radial profile plot.
+
+real procedure ap_cdatamin (ap, gd, out, stid, rmin, rmax, imin, imax)
+
+pointer	ap		# pointer to the apphot structure
+pointer	gd		# pointer to the grapics stream
+int	out		# output file descriptor
+int	stid		# sequence number in output file
+real	rmin, rmax	# x axis limits
+real	imin, imax	# y axis limits
+
+int	wcs, key, stat
+pointer	sp, cmd
+real	datamin, xjunk, yjunk
+int	clgcur()
+real	apstatr(), ap_vdatamin()
+
+begin
+	call smark (sp)
+	call salloc (cmd, SZ_LINE, TY_CHAR)
+
+	# Mark the datamin on the plot.
+	call printf ("Mark the good data minimum (%g) counts:")
+	    call pargr (apstatr (ap, DATAMIN))
+	if (IS_INDEFR (apstatr (ap, DATAMIN)))
+	    call gscur (gd, (rmin + rmax) / 2.0, imin - 1.0)
+	else
+	    call gscur (gd, (rmin + rmax) / 2.0, apstatr (ap, DATAMIN))
+	stat = clgcur ("gcommands", xjunk, yjunk, wcs, key, Memc[cmd], SZ_LINE)
+	if (stat == EOF || yjunk < imin || yjunk > imax)
+	    datamin = apstatr (ap, DATAMIN)
+	else
+	    datamin = yjunk
+
+	# Verify the results.
+	call apsetr (ap, DATAMIN, datamin)
+	datamin = ap_vdatamin (ap)
+
+	# Store the results.
+	if (out != NULL && stid > 1)
+	    call ap_rparam (out, KY_DATAMIN, datamin, UN_ACOUNTS,
+	        "minimum good data value")
+	call sfree (sp)
+
+	return (datamin)
+end
+
+
+# AP_CDATAMAX -- Read the good data maximum off the radial profile plot.
+
+real procedure ap_cdatamax (ap, gd, out, stid, rmin, rmax, imin, imax)
+
+pointer	ap		# pointer to the apphot structure
+pointer	gd		# pointer to the grapics stream
+int	out		# output file descriptor
+int	stid		# sequence number in output file
+real	rmin, rmax	# x axis limits
+real	imin, imax	# y axis limits
+
+int	wcs, key, stat
+pointer	sp, cmd
+real	datamax, xjunk, yjunk
+int	clgcur()
+real	apstatr(), ap_vdatamax()
+
+begin
+	call smark (sp)
+	call salloc (cmd, SZ_LINE, TY_CHAR)
+
+	# Mark the datamax on the plot.
+	call printf ("Mark the good data maximum (%g) counts:")
+	    call pargr (apstatr (ap, DATAMAX))
+	if (IS_INDEFR (apstatr (ap, DATAMAX)))
+	    call gscur (gd, (rmin + rmax) / 2.0, imax + 1.0)
+	else
+	    call gscur (gd, (rmin + rmax) / 2.0, apstatr (ap, DATAMAX))
+	stat = clgcur ("gcommands", xjunk, yjunk, wcs, key, Memc[cmd], SZ_LINE)
+	if (stat == EOF || yjunk < imin || yjunk > imax)
+	    datamax = apstatr (ap, DATAMAX)
+	else
+	    datamax = yjunk
+
+	# Verify the result.
+	call apsetr (ap, DATAMAX, datamax)
+	datamax = ap_vdatamax (ap)
+
+	# Store the results.
+	if (out != NULL && stid > 1)
+	    call ap_rparam (out, KY_DATAMAX, datamax, UN_ACOUNTS,
+	        "maximum good data value")
+	call sfree (sp)
+
+	return (datamax)
+end
+
+
+# AP_CCAPERT -- Read the centering aperture of the radial profile plot.
+
+real procedure ap_ccapert (ap, gd, out, stid, rmin, rmax, imin, imax)
+
+pointer	ap		# pointer to the apphot structure
+pointer	gd		# pointer to the grapics stream
+int	out		# output file descriptor
+int	stid		# output file sequence number
+real	rmin, rmax	# x axis limits
+real	imin, imax	# y axis limits
+
+int	wcs, key, stat
+pointer	sp, cmd
+real	scale, capert, xjunk, yjunk
+int	clgcur()
+real	apstatr(), ap_vcapert()
+
+begin
+	call smark (sp)
+	call salloc (cmd, SZ_LINE, TY_CHAR)
+	scale = apstatr (ap, SCALE)
+
+	# Mark the centering aperture on the plot.
+	call printf ("Mark centering box half width (%g) pixels:")
+	    call pargr (apstatr (ap, CAPERT) * scale)
+	call gscur (gd, apstatr (ap, CAPERT) * scale, (imin + imax) / 2.0)
+	stat = clgcur ("gcommands", xjunk, yjunk, wcs, key, Memc[cmd], SZ_LINE)
+	if (stat == EOF || xjunk <= 0.0 || xjunk > rmax)
+	    capert = apstatr (ap, CAPERT)
+	else
+	    capert = xjunk / scale
+
+	# Verify the results.
+	call apsetr (ap, CAPERT, capert)
+	capert = ap_vcapert (ap)
+
+	# Store the results.
+	if (out != NULL && stid > 1)
+	    call ap_rparam (out, KY_CAPERT, 2.0 * capert, UN_CSCALEUNIT,
+	        "centering box width")
+	call sfree (sp)
+
+	return (capert)
+end
+
+
+# AP_CRCLEAN -- Read the cleaning radius off the radial profile plot.
+
+real procedure ap_crclean (ap, gd, out, stid, rmin, rmax, imin, imax)
+
+pointer	ap		# pointer to the apphot structure
+pointer	gd		# pointer to the grapics stream
+int	out		# output file descriptor
+int	stid		# sequence number in output file
+real	rmin, rmax	# x axis limits
+real	imin, imax	# y axis limits
+
+int	wcs, key, stat
+pointer	sp, cmd
+real	scale, rclean, xjunk, yjunk
+int	clgcur()
+real	apstatr(), ap_vrclean()
+
+begin
+	call smark (sp)
+	call salloc (cmd, SZ_LINE, TY_CHAR)
+	scale = apstatr (ap, SCALE)
+
+	# Mark the cleaning radius on the plot.
+	call printf (
+	    "Mark the centering algorithm cleaning radius (%g) pixels:")
+	    call pargr (apstatr (ap, RCLEAN) * scale)
+	call gscur (gd, apstatr (ap, RCLEAN) * scale, (imin + imax) /
+	    2.0)
+	stat = clgcur ("gcommands", xjunk, yjunk, wcs, key, Memc[cmd], SZ_LINE)
+	if (stat == EOF || xjunk <= 0.0 || xjunk > rmax)
+	    rclean = apstatr (ap, RCLEAN)
+	else
+	    rclean = xjunk / scale
+
+	# Verify the results.
+	call apsetr (ap, RCLEAN, rclean)
+	rclean = ap_vrclean (ap)
+
+	# Save the results.
+	if (out != NULL && stid > 1)
+	    call ap_rparam (out, KY_RCLEAN, rclean, UN_CSCALEUNIT,
+		"cleaning radius")
+	call sfree (sp)
+
+	return (rclean)
+end
+
+
+# AP_CRCLIP -- Read the clipping radius off the radial profile plot.
+
+real procedure ap_crclip (ap, gd, out, stid, rmin, rmax, imin, imax)
+
+pointer	ap		# pointer to the apphot structure
+pointer	gd		# pointer to the grapics stream
+int	out		# output file descriptor
+int	stid		# sequence number in output file
+real	rmin, rmax	# x axis limits
+real	imin, imax	# y axis limits
+
+int	wcs, key, stat
+pointer	sp, cmd
+real	scale, rclip, xjunk, yjunk
+int	clgcur()
+real	apstatr(), ap_vrclip()
+
+begin
+	call smark (sp)
+	call salloc (cmd, SZ_LINE, TY_CHAR)
+	scale = apstatr (ap, SCALE)
+
+	# Mark clipping radius on the plot.
+	call printf (
+	    "Mark the centering algorithm clipping radius (%g) pixels:")
+	    call pargr (apstatr (ap, RCLIP) * scale)
+	call gscur (gd, apstatr (ap, RCLIP) * scale, (imin + imax) /
+	    2.0)
+	stat = clgcur ("gcommands", xjunk, yjunk, wcs, key, Memc[cmd], SZ_LINE)
+	if (stat == EOF || xjunk <= 0.0 || xjunk > rmax)
+	    rclip = apstatr (ap, RCLIP)
+	else
+	    rclip = xjunk / scale
+
+	# Verify the results.
+	call apsetr (ap, RCLIP, rclip)
+	rclip = ap_vrclip (ap)
+
+	# Save the results.
+	if (out != NULL && stid > 1)
+	    call ap_rparam (out, KY_RCLIP, rclip, UN_CSCALEUNIT,
+	        "clipping radius")
+	call sfree (sp)
+
+	return (rclip)
+end
+
+
+# AP_CANNULUS -- Read the sky annulus of the radial profile plot.
+
+real procedure ap_cannulus (ap, gd, out, stid, rmin, rmax, imin, imax)
+
+pointer	ap		# pointer to the apphot structure
+pointer	gd		# pointer to the grapics stream
+int	out		# output file descriptor
+int	stid		# output file sequence number
+real	rmin, rmax	# x axis limits
+real	imin, imax	# y axis limits
+
+int	wcs, key, stat
+pointer	sp, cmd
+real	scale, annulus, xjunk, yjunk
+int	clgcur()
+real	apstatr(), ap_vannulus()
+
+begin
+	call smark (sp)
+	call salloc (cmd, SZ_LINE, TY_CHAR)
+	scale = apstatr (ap, SCALE)
+
+	# Mark the inner sky radius.
+	call printf ("Mark inner sky radius (%g) pixels:")
+	    call pargr (apstatr (ap, ANNULUS) * apstatr (ap, SCALE))
+	call gscur (gd, apstatr (ap, ANNULUS) * apstatr (ap, SCALE),
+	    (imin + imax) / 2.0)
+	stat = clgcur ("gcommands", xjunk, yjunk, wcs, key, Memc[cmd], SZ_LINE)
+	if (stat == EOF || xjunk < 0.0 || xjunk > rmax)
+	    annulus = apstatr (ap, ANNULUS)
+	else
+	    annulus = xjunk / scale
+
+	# Verify the result.
+	call apsetr (ap, ANNULUS, annulus)
+	annulus = ap_vannulus (ap)
+
+	# Save the results.
+	if (out != NULL && stid > 1)
+	    call ap_rparam (out, KY_ANNULUS, annulus, UN_SSCALEUNIT,
+		"radius of the inner sky annulus")
+	call sfree (sp)
+
+	return (annulus)
+end
+
+
+# AP_CRGROW -- Read the region growing radius off the radial profile plot.
+
+real procedure ap_crgrow (ap, gd, out, stid, rmin, rmax, imin, imax)
+
+pointer	ap		# pointer to the apphot structure
+pointer	gd		# pointer to the grapics stream
+int	out		# the output file descriptor
+int	stid		# output file sequence number
+real	rmin, rmax	# x axis limits
+real	imin, imax	# y axis limits
+
+int	wcs, key, stat
+pointer	sp, cmd
+real	scale, rgrow, xjunk, yjunk
+int	clgcur()
+real	apstatr(), ap_vrgrow()
+
+begin
+	call smark (sp)
+	call salloc (cmd, SZ_LINE, TY_CHAR)
+	scale = apstatr (ap, SCALE)
+
+	# Mark the inner sky radius.
+	call printf ("Mark region growing radius (%g) pixels:")
+	    call pargr (apstatr (ap, RGROW) * apstatr (ap, SCALE))
+	call gscur (gd, apstatr (ap, RGROW) * apstatr (ap, SCALE),
+	    (imin + imax) / 2.0)
+	stat = clgcur ("gcommands", xjunk, yjunk, wcs, key, Memc[cmd], SZ_LINE)
+	if (stat == EOF || xjunk < 0.0 || xjunk > rmax)
+	    rgrow = apstatr (ap, RGROW)
+	else
+	    rgrow = xjunk / scale
+
+	# Verify the region growing radius.
+	call apsetr (ap, RGROW, rgrow)
+	rgrow = ap_vrgrow (ap) 
+
+	# Save the results.
+	if (out != NULL && stid > 1)
+	    call ap_rparam (out, KY_RGROW, rgrow, UN_SSCALEUNIT,
+	        "region growing radius")
+	call sfree (sp)
+
+	return (rgrow)
+end
+
+
+# AP_CDANNULUS -- Read the sky annulus width off the radial profile plot.
+
+real procedure ap_cdannulus (ap, gd, out, stid, annulus, rmin, rmax, imin, imax)
+
+pointer	ap		# pointer to the apphot structure
+pointer	gd		# pointer to the grapics stream
+int	out		# output file descriptor
+int	stid		# output file sequence number
+real	rmin, rmax	# x axis limits
+real	imin, imax	# y axis limits
+
+int	wcs, key, stat
+pointer	sp, cmd
+real	scale, annulus, dannulus, xjunk, yjunk
+int	clgcur()
+real	apstatr(), ap_vdannulus()
+
+begin
+	call smark (sp)
+	call salloc (cmd, SZ_LINE, TY_CHAR)
+	scale = apstatr (ap, SCALE)
+
+	# Mark the outer sky radius.
+	call printf ("Mark outer sky radius (%g) pixels:")
+	    call pargr (apstatr (ap, SCALE) * (apstatr (ap, ANNULUS) +
+		apstatr (ap, DANNULUS)))
+	call gscur (gd, apstatr (ap, SCALE) * (apstatr (ap, ANNULUS) +
+	    apstatr (ap, DANNULUS)), (imin + imax) / 2.0)
+	stat = clgcur ("gcommands", xjunk, yjunk, wcs, key, Memc[cmd], SZ_LINE)
+	if (stat == EOF || (xjunk / scale < annulus) || xjunk > rmax)
+	    dannulus = apstatr (ap, DANNULUS)
+	else
+	    dannulus = (xjunk / scale - annulus)
+
+	# Verify the width of the annulus.
+	call apsetr (ap, DANNULUS, dannulus)
+	dannulus = ap_vdannulus (ap)
+
+	# Save the results.
+	if (out != NULL && stid > 1)
+	    call ap_rparam (out, KY_DANNULUS, dannulus, UN_SSCALEUNIT,
+	        "width of the sky annulus")
+	call sfree (sp)
+
+	return (dannulus)
+end
+
+
+# AP_CSIGMA -- Read the sky sigma from the radial profile plot.
+
+real procedure ap_csigma (ap, gd, out, stid, rmin, rmax, imin, imax)
+
+pointer	ap		# pointer to the apphot structure
+pointer	gd		# pointer to the grapics stream
+int	out		# output file descriptor
+int	stid		# sequence number in output file
+real	rmin, rmax	# x axis limits
+real	imin, imax	# y axis limits
+
+int	wcs, key, stat
+pointer	sp, cmd
+real	mean, sigma3, xjunk, yjunk
+int	clgcur()
+int	apstati()
+real	apstatr(), ap_vsigma()
+
+begin
+	call smark (sp)
+	call salloc (cmd, SZ_LINE, TY_CHAR)
+
+	# Estimate the mean sky.
+	if (apstati (ap, POSITIVE) == YES)
+	    mean = imin
+	else
+	    mean = imax
+	call printf ("Estimate sky sigma. Mark mean sky level (%g):")
+	    call pargr (mean)
+	call gscur (gd, (rmin + rmax) / 2.0, mean)
+	stat = clgcur ("gcommands", xjunk, yjunk, wcs, key, Memc[cmd], SZ_LINE)
+	if (stat == EOF || yjunk < imin || yjunk > imax)
+	    mean = mean
+	else
+	    mean = yjunk 
+
+	# Estimate the sky sigma.
+	if (IS_INDEFR (apstatr (ap, SKYSIGMA)))
+	    sigma3 = INDEFR
+	else
+	    sigma3 = 3.0 * apstatr (ap, SKYSIGMA)
+	call printf ("Next mark 3 sigma sky level (%g):")
+	    call pargr (sigma3)
+	if (IS_INDEFR(sigma3))
+	    call gscur (gd, (rmin + rmax) / 2.0, imin - 1.0)
+	else
+	    call gscur (gd, (rmin + rmax) / 2.0, mean + sigma3)
+	stat = clgcur ("gcommands", xjunk, yjunk, wcs, key, Memc[cmd], SZ_LINE)
+        if (stat == EOF || yjunk < imin || yjunk > imax) {
+	    sigma3 = apstatr (ap, SKYSIGMA)
+	    if (! IS_INDEFR (sigma3))
+		sigma3 = 3.0 * sigma3
+	} else
+	    sigma3 = abs (yjunk - mean)
+
+	# Verify the results.
+	if (IS_INDEFR(sigma3))
+	    call apsetr (ap, SKYSIGMA, INDEFR) 
+	else
+	    call apsetr (ap, SKYSIGMA, sigma3 / 3.0)
+	sigma3 = ap_vsigma (ap)
+
+	# Save the results.
+	if (out != NULL && stid > 1)
+	    call ap_rparam (out, KY_SKYSIGMA, sigma3, UN_NCOUNTS,
+	        "standard deviation of 1 sky pixel")
+
+	call sfree (sp)
+
+	if (IS_INDEFR(sigma3))
+	    return (sigma3)
+	else
+	    return (sigma3 / 3.0)
+end
+
+
+# AP_CAPER -- Read the apertures off the radial profile plot.
+
+procedure ap_caper (ap, gd, out, stid, outstr, rmin, rmax, imin, imax)
+
+pointer	ap		# pointer to the apphot structure
+pointer	gd		# pointer to the grapics stream
+int	out		# output file descriptor
+int	stid		# output file number sequence
+char	outstr[ARB]	# output apertures
+real	rmin, rmax	# x axis limits
+real	imin, imax	# y axis limits
+
+int	i, wcs, key, naperts
+pointer	sp, cmd, tstr, aperts
+real	scale, xjunk, yjunk
+int	clgcur()
+int	apstati(), strlen()
+real	apstatr()
+
+begin
+	call smark (sp)
+	call salloc (cmd, SZ_LINE, TY_CHAR)
+	call salloc (tstr, SZ_LINE, TY_CHAR)
+	scale = apstatr (ap, SCALE)
+
+	# Get the apertures.
+	naperts = apstati (ap, NAPERTS)
+	call salloc (aperts, naperts, TY_REAL)
+	call ap_arrayr (ap, APERTS, Memr[aperts])
+
+	# Encode the old aperture string.
+	outstr[1] = EOS
+	do i = 1, naperts - 1 {
+	    call sprintf (outstr[1+strlen(outstr)], SZ_FNAME,"%.2f,")
+		call pargr (Memr[aperts+i-1] * scale)
+	}
+	call sprintf (outstr[1+strlen(outstr)], SZ_FNAME,"%.2f")
+	    call pargr (Memr[aperts+naperts-1] * scale)
+
+	# Type prompt string.
+	call printf ("Mark apertures (%s) pixels [q=quit]:")
+	    call pargstr (outstr)
+	call gscur (gd, Memr[aperts] * scale, (imin + imax) / 2.0)
+
+	# Mark the apertures.
+	outstr[1] = EOS
+	Memc[tstr] = EOS
+	while (clgcur ("gcommands", xjunk, yjunk, wcs, key, Memc[cmd],
+	    SZ_LINE) != EOF) {
+	    if (key == 'q')
+		break
+	    if (xjunk <= 0.0 || xjunk > rmax)
+		next
+	    call sprintf (outstr[1+strlen(outstr)], SZ_FNAME,"%.2f,")
+		call pargr (xjunk / scale)
+	    call sprintf (Memc[tstr+strlen(Memc[tstr])], SZ_FNAME,"%.2f,")
+		call pargr (xjunk)
+	    call printf ("Mark apertures (%s) pixels [q=quit]:")
+	        call pargstr (Memc[tstr])
+	}
+	outstr[strlen(outstr)] = EOS
+
+	# Verify the results.
+	call apsets (ap, APERTS, outstr)
+	call ap_vaperts (ap, outstr, SZ_LINE)
+
+	# Save the results.
+	if (out != NULL && stid > 1)
+	    call ap_sparam (out, KY_APERTS, outstr, UN_PSCALEUNIT,
+	        "list of aperture radii")
+
+	call sfree (sp)
+end
diff --git a/noao/digiphot/apphot/aplib/aprcursor2.x b/noao/digiphot/apphot/aplib/aprcursor2.x
new file mode 100644
index 00000000..e24049b5
--- /dev/null
+++ b/noao/digiphot/apphot/aplib/aprcursor2.x
@@ -0,0 +1,144 @@
+include "../lib/apphot.h"
+include "../lib/radprof.h"
+include "../lib/fitpsf.h"
+
+# AP_CRPROF -- Read the radial profile size off the radial profile plot.
+
+real procedure ap_crprof (ap, gd, out, stid, rmin, rmax, imin, imax)
+
+pointer	ap		# pointer to the apphot structure
+pointer	gd		# pointer to the grapics stream
+int	out		# output file descriptor
+int	stid		# output file sequence number
+real	rmin, rmax	# x axis limits
+real	imin, imax	# y axis limits
+
+int	wcs, key, stat
+pointer	sp, cmd
+real	scale, radius, xjunk, yjunk
+int	clgcur()
+real	apstatr(), ap_vrpradius()
+
+begin
+	call smark (sp)
+	call salloc (cmd, SZ_LINE, TY_CHAR)
+	scale = apstatr (ap, SCALE)
+
+	# Estimate the minimum (maximum) data level.
+	# Mark maximum radius of the radial profile.
+	call printf ("Mark maximum radius for profile (%g) pixels:")
+	    call pargr (apstatr (ap, RPRADIUS) * scale)
+	call gscur (gd, apstatr (ap, RPRADIUS) * scale, (imin + imax) / 2.0)
+	stat = clgcur ("gcommands", xjunk, yjunk, wcs, key, Memc[cmd], SZ_LINE)
+	if (stat == EOF || xjunk < 0.0 || xjunk > rmax)
+	    radius = apstatr (ap, RPRADIUS)
+	else
+	    radius = xjunk / scale
+
+	# Verify the results.
+	call apsetr (ap, RPRADIUS, radius)
+	radius = ap_vrpradius (ap)
+
+	# Store the results.
+	if (out != NULL && stid > 1)
+	    call ap_rparam (out, KY_RPRADIUS, radius, UN_RSCALEUNIT,
+	        "fitting radius")
+
+	call sfree (sp)
+
+	return (radius)
+end
+
+
+# AP_CRPSTEP -- Read the radial profile size off the radial profile plot.
+
+real procedure ap_crpstep (ap, gd, out, stid, rmin, rmax, imin, imax)
+
+pointer	ap		# pointer to the apphot structure
+pointer	gd		# pointer to the grapics stream
+int	out		# output file descriptor
+int	stid		# output file sequence number
+real	rmin, rmax	# x axis limits
+real	imin, imax	# y axis limits
+
+int	wcs, key, stat
+pointer	sp, cmd
+real	scale, step, xjunk, yjunk
+int	clgcur()
+real	apstatr(), ap_vstep()
+
+begin
+	call smark (sp)
+	call salloc (cmd, SZ_LINE, TY_CHAR)
+	scale = apstatr (ap, SCALE)
+
+	# Mark the radial profile step size.
+	call printf ("Mark step size (%g) pixels:")
+	    call pargr (apstatr (ap, RPSTEP) * scale)
+	call gscur (gd, apstatr (ap, RPSTEP) * scale, (imin + imax) / 2.0)
+	stat = clgcur ("gcommands", xjunk, yjunk, wcs, key, Memc[cmd], SZ_LINE)
+	if (stat == EOF || xjunk < 0.0 || xjunk > rmax)
+	    step = apstatr (ap, RPSTEP)
+	else
+	    step = xjunk / scale
+
+	# Verify the results.
+	call apsetr (ap, RPSTEP, step)
+	step = ap_vstep (ap)
+
+	# Store the results.
+	if (out != NULL && stid > 1)
+	    call ap_rparam (out, KY_RPSTEP, step, UN_RSCALEUNIT,
+	        "step size in pixels")
+
+	call sfree (sp)
+
+	return (step)
+end
+
+
+# AP_CPAPERT -- Read the fitting radius on the radial profile plot.
+
+real procedure ap_cpapert (ap, gd, out, stid, rmin, rmax, imin, imax)
+
+pointer	ap		# pointer to the apphot structure
+pointer	gd		# pointer to the grapics stream
+int	out		# output file descriptor
+int	stid		# output file sequence number
+real	rmin, rmax	# x axis limits
+real	imin, imax	# y axis limits
+
+int	wcs, key, stat
+pointer	sp, cmd
+real	scale, psfapert, xjunk, yjunk
+int	clgcur()
+real	apstatr(), ap_vpsfapert()
+
+begin
+	call smark (sp)
+	call salloc (cmd, SZ_LINE, TY_CHAR)
+	scale = apstatr (ap, SCALE)
+
+	# Mark the fitting radius on the plot.
+	call printf ("Mark fitting box half width (%g) pixels:")
+	    call pargr (apstatr (ap, PSFAPERT) * scale)
+	call gscur (gd, apstatr (ap, PSFAPERT) * scale, (imin + imax) / 2.0)
+	stat = clgcur ("gcommands", xjunk, yjunk, wcs, key, Memc[cmd], SZ_LINE)
+	if (stat == EOF || xjunk <= 0.0 || xjunk > rmax)
+	    psfapert = apstatr (ap, PSFAPERT)
+	else
+	    psfapert = xjunk / scale
+
+	# Verify the results.
+	call apsetr (ap, PSFAPERT, psfapert)
+	psfapert = ap_vpsfapert (ap)
+
+	# Store the results.
+	if (out != NULL && stid > 1)
+	    call ap_rparam (out, KY_PSFAPERT, 2.0 * psfapert, UN_PSFSCALEUNIT,
+	        "width of the fitting box")
+
+	call sfree (sp)
+
+	return (psfapert)
+end
diff --git a/noao/digiphot/apphot/aplib/aprdnoise.x b/noao/digiphot/apphot/aplib/aprdnoise.x
new file mode 100644
index 00000000..e4fbda2c
--- /dev/null
+++ b/noao/digiphot/apphot/aplib/aprdnoise.x
@@ -0,0 +1,36 @@
+include <imhdr.h>
+include "../lib/noise.h"
+
+# AP_RDNOISE -  Procedure to set the image read noise parameter.
+
+procedure ap_rdnoise (im, ap)
+
+pointer	im		# pointer to IRAF image
+pointer	ap		# pointer to apphot structure
+
+pointer	sp, key
+real	rdnoise
+real	imgetr(), apstatr()
+
+begin
+	call smark (sp)
+	call salloc (key, SZ_FNAME, TY_CHAR)
+	call apstats (ap, CCDREAD, Memc[key], SZ_FNAME)
+	if (Memc[key] == EOS)
+	    rdnoise = apstatr (ap, READNOISE)
+	else {
+	    iferr {
+	        rdnoise = imgetr (im, Memc[key])
+	    } then {
+		rdnoise = apstatr (ap, READNOISE)
+		call eprintf ("Warning: Image %s  Keyword %s not found.\n")
+		    call pargstr (IM_HDRFILE(im))
+		    call pargstr (Memc[key])
+	    }
+	}
+	if (IS_INDEFR(rdnoise) || rdnoise <= 0.0)
+	    call apsetr (ap, READNOISE, 0.0)
+	else
+	    call apsetr (ap, READNOISE, rdnoise)
+	call sfree (sp)
+end
diff --git a/noao/digiphot/apphot/aplib/apset.x b/noao/digiphot/apphot/aplib/apset.x
new file mode 100644
index 00000000..2248f561
--- /dev/null
+++ b/noao/digiphot/apphot/aplib/apset.x
@@ -0,0 +1,72 @@
+define	MAXERR1		500
+define	MAXERR2		1000
+
+
+# APSETS -- Procedure to set an apphot string parameter.
+
+procedure apsets (ap, param, str)
+
+pointer	ap		# pointer to apphot structure
+int	param		# parameter
+char	str[ARB]	# string parameter
+
+begin
+	if (param <= MAXERR1)
+	    call ap1sets (ap, param, str)
+	else if (param <= MAXERR2)
+	    call ap2sets (ap, param, str)
+end
+
+
+# APSETI -- Procedure to set an integer apphot parameter.
+
+procedure apseti (ap, param, ival)
+
+pointer	ap		# pointer to apphot structure
+int	param		# parameter
+int	ival		# integer value
+
+begin
+	if (param <= MAXERR1)
+	    call ap1seti (ap, param, ival)
+	else if (param <= MAXERR2)
+	    call ap2seti (ap, param, ival)
+	else
+	    call error (0, "Unknown APPHOT integer parameter")
+end
+
+
+# APSETR -- Procedure to set a real apphot parameter.
+
+procedure apsetr (ap, param, rval)
+
+pointer	ap		# pointer to apphot structure
+int	param		# parameter
+real	rval		# real value
+
+begin
+	if (param <= MAXERR1)
+	    call ap1setr (ap, param, rval)
+	else if (param <= MAXERR2)
+	    call ap2setr (ap, param, rval)
+	else
+	    call error (0, "Unknown APPHOT real parameter")
+end
+
+
+# APSETD -- Procedure to set a double apphot parameter.
+
+procedure apsetd (ap, param, dval)
+
+pointer	ap		# pointer to apphot structure
+int	param		# parameter
+double	dval		# double value
+
+begin
+	if (param <= MAXERR1)
+	    call ap1setd (ap, param, dval)
+	else if (param <= MAXERR2)
+	    call ap2setd (ap, param, dval)
+	else
+	    call error (0, "Unknown APPHOT double parameter")
+end
diff --git a/noao/digiphot/apphot/aplib/apset1.x b/noao/digiphot/apphot/aplib/apset1.x
new file mode 100644
index 00000000..6c4d6f1b
--- /dev/null
+++ b/noao/digiphot/apphot/aplib/apset1.x
@@ -0,0 +1,330 @@
+include "../lib/apphotdef.h"
+include "../lib/apphot.h"
+include "../lib/centerdef.h"
+include "../lib/center.h"
+include "../lib/fitskydef.h"
+include "../lib/fitsky.h"
+include "../lib/photdef.h"
+include "../lib/phot.h"
+include "../lib/fitpsfdef.h"
+include "../lib/fitpsf.h"
+
+# AP1SETS -- Procedure to set an apphot string parameter.
+
+procedure ap1sets (ap, param, str)
+
+pointer	ap		# pointer to apphot structure
+int	param		# parameter
+char	str[ARB]	# string parameter
+
+int	naperts
+pointer	ctr, sky, phot, psf
+real	aperts[MAX_NAPERTS]
+int	ap_getaperts()
+
+begin
+	ctr = AP_PCENTER(ap)
+	sky = AP_PSKY(ap)
+	phot = AP_PPHOT(ap)
+	psf = AP_PPSF(ap)
+
+	switch (param) {
+	case IMNAME:
+	    call strcpy (str, AP_IMNAME(ap), SZ_FNAME)
+	case IMROOT:
+	    call strcpy (str, AP_IMROOT(ap), SZ_FNAME)
+	case CLNAME:
+	    call strcpy (str, AP_CLNAME(ap), SZ_FNAME)
+	case CLROOT:
+	    call strcpy (str, AP_CLROOT(ap), SZ_FNAME)
+	case PLOTFILE:
+	    call strcpy (str, AP_PLOTFILE(ap), SZ_FNAME)
+	case OUTNAME:
+	    call strcpy (str, AP_OUTNAME(ap), SZ_FNAME)
+	case EXPOSURE:
+	    call strcpy (str, AP_EXPOSURE(ap), SZ_FNAME)
+	case AIRMASS:
+	    call strcpy (str, AP_AIRMASS(ap), SZ_FNAME)
+	case FILTER:
+	    call strcpy (str, AP_FILTER(ap), SZ_FNAME)
+	case FILTERID:
+	    call strcpy (str, AP_FILTERID(ap), SZ_FNAME)
+	case OBSTIME:
+	    call strcpy (str, AP_OBSTIME(ap), SZ_FNAME)
+	case OTIME:
+	    call strcpy (str, AP_OTIME(ap), SZ_FNAME)
+
+	case CSTRING:
+	    call strcpy (str, AP_CSTRING(ctr), SZ_FNAME)
+
+	case SSTRING:
+	    call strcpy (str, AP_SSTRING(sky), SZ_FNAME)
+
+	case APSTRING:
+	    call strcpy (str, AP_APSTRING(phot), SZ_FNAME)
+	case APERTS:
+	    naperts = ap_getaperts (str, aperts, MAX_NAPERTS)
+	    if (naperts > 0) {
+		call strcpy (str, AP_APSTRING(phot), SZ_LINE)
+		AP_NAPERTS(phot) = naperts
+	        call realloc (AP_APERTS(phot), AP_NAPERTS(phot), TY_REAL)
+	        call realloc (AP_AREA(phot), AP_NAPERTS(phot), TY_DOUBLE)
+	        call realloc (AP_SUMS(phot), AP_NAPERTS(phot), TY_DOUBLE)
+	        call realloc (AP_MAGS(phot), AP_NAPERTS(phot), TY_REAL)
+	        call realloc (AP_MAGERRS(phot), AP_NAPERTS(phot), TY_REAL)
+	        call amovr (aperts, Memr[AP_APERTS(phot)], AP_NAPERTS(phot))
+	        call asrtr (Memr[AP_APERTS(phot)], Memr[AP_APERTS(phot)],
+	            AP_NAPERTS(phot))
+	    }
+	case PWSTRING:
+	    call strcpy (str, AP_PWSTRING(phot), SZ_FNAME)
+
+	case PSFSTRING:
+	    call strcpy (str, AP_PSFSTRING(psf), SZ_FNAME)
+
+	default:
+	    call error (0, "APSETS: Unknown apphot string parameter")
+	}
+end
+
+
+# AP1SETI -- Procedure to set an integer apphot parameter.
+
+procedure ap1seti (ap, param, ival)
+
+pointer	ap		# pointer to apphot structure
+int	param		# parameter
+int	ival		# integer value
+
+pointer	cen, sky, phot, psf
+
+begin
+	cen = AP_PCENTER(ap)
+	sky = AP_PSKY(ap)
+	phot = AP_PPHOT(ap)
+	psf = AP_PPSF(ap)
+
+	switch (param) {
+	case POSITIVE:
+	    AP_POSITIVE(ap) = ival
+	case WCSIN:
+	    AP_WCSIN(ap) = ival
+	case WCSOUT:
+	    AP_WCSOUT(ap) = ival
+	case MW:
+	    AP_MW(ap) = ival
+	case CTIN:
+	    AP_CTIN(ap) = ival
+	case CTOUT:
+	    AP_CTOUT(ap) = ival
+
+	case CENTERFUNCTION:
+	    AP_CENTERFUNCTION(cen) = ival
+	case CLEAN:
+	    AP_CLEAN(cen) = ival
+	case CMAXITER:
+	    AP_CMAXITER(cen) = ival
+
+	case SKYFUNCTION:
+	    AP_SKYFUNCTION(sky) = ival
+	case SMAXITER:
+	    AP_SMAXITER(sky) = ival
+	case SNREJECT:
+	    AP_SNREJECT(sky) = ival
+	case SMOOTH:
+	    AP_SMOOTH(sky) = ival
+	case NSKY:
+	    AP_NSKY(sky) = ival
+	case NSKY_REJECT:
+	    AP_NSKY_REJECT(sky) = ival
+
+	case PWEIGHTS:
+	    AP_PWEIGHTS(phot) = ival
+
+	case PSFUNCTION:
+	    AP_PSFUNCTION(psf) = ival
+	case NPARS:
+	    AP_PSFNPARS(psf) = ival
+	case MAXNPARS:
+	    AP_MAXNPARS(psf) = ival
+	case PMAXITER:
+	    AP_PMAXITER(psf) = ival
+	case PNREJECT:
+	    AP_PNREJECT(psf) = ival
+
+	default:
+	    call error (0, "APSETI: Unknown apphot integer parameter")
+	}
+end
+
+
+# AP1SETR -- Procedure to set a real apphot parameter.
+
+procedure ap1setr (ap, param, rval)
+
+pointer	ap		# pointer to apphot structure
+int	param		# parameter
+real	rval		# real value
+
+pointer	cen, sky, phot, psf
+
+begin
+	cen = AP_PCENTER(ap)
+	sky = AP_PSKY(ap)
+	phot = AP_PPHOT(ap)
+	psf = AP_PPSF(ap)
+
+	switch (param) {
+
+	case FWHMPSF:
+	    AP_FWHMPSF(ap) = rval
+	case SCALE:
+	    AP_SCALE(ap) =  rval
+	case WX:
+	    AP_WX(ap) = rval
+	case WY:
+	    AP_WY(ap) = rval
+	case ITIME:
+	    AP_ITIME(ap) = rval
+	case CWX:
+	    AP_CWX(ap) = rval
+	case CWY:
+	    AP_CWY(ap) = rval
+	case DATAMIN:
+	    AP_DATAMIN(ap) = rval
+	case DATAMAX:
+	    AP_DATAMAX(ap) = rval
+	case XAIRMASS:
+	    AP_XAIRMASS(ap) = rval
+
+	case CDATALIMIT:
+	    AP_CDATALIMIT(cen) = rval
+	case XSHIFT:
+	    AP_XSHIFT(cen) = rval
+	case YSHIFT:
+	    AP_YSHIFT(cen) = rval
+	case OXSHIFT:
+	    AP_OXSHIFT(cen) = rval
+	case OYSHIFT:
+	    AP_OYSHIFT(cen) = rval
+	case CXCUR:
+	    AP_CXCUR(cen) = rval
+	case CYCUR:
+	    AP_CYCUR(cen) = rval
+	case CAPERT:
+	    AP_CAPERT(cen) = rval
+	case CTHRESHOLD:
+	    AP_CTHRESHOLD(cen) = rval
+	case MAXSHIFT:
+	    AP_MAXSHIFT(cen) = rval
+	case MINSNRATIO:
+	    AP_MINSNRATIO(cen) = rval
+	case RCLEAN:
+	    AP_RCLEAN(cen) = rval
+	case RCLIP:
+	    AP_RCLIP(cen) = rval
+	case SIGMACLEAN:
+	    AP_SIGMACLEAN(cen) = rval
+	case OXINIT:
+	    AP_OXINIT(cen) = rval
+	case OYINIT:
+	    AP_OYINIT(cen) = rval
+	case XCENTER:
+	    AP_XCENTER(cen) = rval
+	case YCENTER:
+	    AP_YCENTER(cen) = rval
+	case OXCENTER:
+	    AP_OXCENTER(cen) = rval
+	case OYCENTER:
+	    AP_OYCENTER(cen) = rval
+	case XERR:
+	    AP_XERR(cen) = rval
+	case YERR:
+	    AP_YERR(cen) = rval
+
+	case ANNULUS:
+	    AP_ANNULUS(sky) = rval
+	case DANNULUS:
+	    AP_DANNULUS(sky) = rval
+	case SXCUR:
+	    AP_SXCUR(sky) = rval
+	case SYCUR:
+	    AP_SYCUR(sky) = rval
+	case OSXCUR:
+	    AP_OSXCUR(sky) = rval
+	case OSYCUR:
+	    AP_OSYCUR(sky) = rval
+	case K1:
+	    AP_K1(sky) = rval
+	case SLOREJECT:
+	    AP_SLOREJECT(sky) = rval
+	case SHIREJECT:
+	    AP_SHIREJECT(sky) = rval
+	case SLOCLIP:
+	    AP_SLOCLIP(sky) = rval
+	case SHICLIP:
+	    AP_SHICLIP(sky) = rval
+	case BINSIZE:
+	    AP_BINSIZE(sky) = rval
+	case RGROW:
+	    AP_RGROW(sky) = rval
+	case SKY_BACKGROUND:
+	    AP_SKYBACKGROUND(sky) = rval
+	case SKY_MODE:
+	    AP_SKY_MODE(sky) = rval
+	case SKY_SIGMA:
+	    AP_SKY_SIG(sky) = rval
+	case SKY_SKEW:
+	    AP_SKY_SKEW(sky) = rval
+
+	case PXCUR:
+	    AP_PXCUR(phot) = rval
+	case PYCUR:
+	    AP_PYCUR(phot) = rval
+	case OPXCUR:
+	    AP_OPXCUR(phot) = rval
+	case OPYCUR:
+	    AP_OPYCUR(phot) = rval
+	case ZMAG:
+	    AP_ZMAG(phot) = rval
+
+	case PK2:
+	    AP_PK2(psf) = rval
+	case PSFAPERT:
+	    AP_PSFAPERT(psf) = rval
+	case PFXCUR:
+	    AP_PFXCUR(psf) = rval
+	case PFYCUR:
+	    AP_PFYCUR(psf) = rval
+	case OPFXCUR:
+	    AP_OPFXCUR(psf) = rval
+	case OPFYCUR:
+	    AP_OPFYCUR(psf) = rval
+
+	default:
+	    call error (0, "APSETR: Unknown apphot real parameter")
+	}
+end
+
+
+# AP1SETD -- Procedure to set a double apphot parameter.
+
+procedure ap1setd (ap, param, dval)
+
+pointer	ap		# pointer to apphot structure
+int	param		# parameter
+double	dval		# double value
+
+pointer	cen, sky, phot, psf
+
+begin
+	cen = AP_PCENTER(ap)
+	sky = AP_PSKY(ap)
+	phot = AP_PPHOT(ap)
+	psf = AP_PPSF(ap)
+
+	switch (param) {
+	default:
+	    call error (0, "APSETD: Unknown apphot double parameter")
+	}
+end
diff --git a/noao/digiphot/apphot/aplib/apset2.x b/noao/digiphot/apphot/aplib/apset2.x
new file mode 100644
index 00000000..85200daf
--- /dev/null
+++ b/noao/digiphot/apphot/aplib/apset2.x
@@ -0,0 +1,227 @@
+include "../lib/apphotdef.h"
+include "../lib/apphot.h"
+include "../lib/displaydef.h"
+include "../lib/display.h"
+include "../lib/noisedef.h"
+include "../lib/noise.h"
+include "../lib/polyphotdef.h"
+include "../lib/polyphot.h"
+include "../lib/radprofdef.h"
+include "../lib/radprof.h"
+include "../lib/finddef.h"
+include "../lib/find.h"
+
+# AP2SETS -- Procedure to set an apphot string parameter.
+
+procedure ap2sets (ap, param, str)
+
+pointer	ap		# pointer to apphot structure
+int	param		# parameter
+char	str[ARB]	# string parameter
+
+pointer	nse, ply
+
+begin
+	nse = AP_NOISE(ap)
+	ply = AP_POLY(ap)
+
+	switch (param) {
+	case PYNAME:
+	    call strcpy (str, AP_PYNAME(ply), SZ_FNAME)
+	case PYROOT:
+	    call strcpy (str, AP_PYROOT(ply), SZ_FNAME)
+	case GAIN:
+	    call strcpy (str, AP_GAIN(nse), SZ_FNAME)
+	case NSTRING:
+	    call strcpy (str, AP_NSTRING(nse), SZ_FNAME)
+	case CCDREAD:
+	    call strcpy (str, AP_CCDREAD(nse), SZ_FNAME)
+	default:
+	    call error (0, "APSETS: Unknown apphot string parameter")
+	}
+end
+
+
+# AP2SETI -- Procedure to set an integer apphot parameter.
+
+procedure ap2seti (ap, param, ival)
+
+pointer	ap		# pointer to apphot structure
+int	param		# parameter
+int	ival		# integer value
+
+pointer	dsp, nse, ply, rprof
+
+begin
+	nse = AP_NOISE(ap)
+	dsp = AP_PDISPLAY(ap)
+	ply = AP_POLY(ap)
+	rprof = AP_RPROF(ap)
+
+	switch (param) {
+	case RPORDER:
+	    AP_RPORDER(rprof) = ival
+	case RPNREJECT:
+	    AP_RPNREJECT(rprof) = ival
+	case PYNVER:
+	    AP_PYNVER(ply) = ival
+	case PYBADPIX:
+	    AP_PYBADPIX(ply) = ival
+	case MKSKY:
+	    AP_MKSKY(dsp) = ival
+	case MKCENTER:
+	    AP_MKCENTER(dsp) = ival
+	case MKAPERT:
+	    AP_MKAPERT(dsp) = ival
+	case MKPOLYGON:
+	    AP_MKPOLYGON(dsp) = ival
+	case MKDETECTIONS:
+	    AP_MKDETECTIONS(dsp) = ival
+	case NOISEFUNCTION:
+	    AP_NOISEFUNCTION(nse) = ival
+	case MKPSFBOX:
+	    AP_MKPSFBOX(dsp) = ival
+	case RADPLOTS:
+	    AP_RADPLOTS(dsp) = ival
+	case RPNPTS:
+	    AP_RPNPTS(rprof) = ival
+	case RPNDATA:
+	    AP_RPNDATA(rprof) = ival
+	case RPNDATAREJ:
+	    AP_RPNDATAREJ(rprof) = ival
+	default:
+	    call error (0, "APSETI: Unknown apphot integer parameter")
+	}
+end
+
+
+# AP2SETR -- Procedure to set a real apphot parameter.
+
+procedure ap2setr (ap, param, rval)
+
+pointer	ap		# pointer to apphot structure
+int	param		# parameter
+real	rval		# real value
+
+pointer	nse, ply, rprof, fnd
+
+begin
+	nse = AP_NOISE(ap)
+	ply = AP_POLY(ap)
+	rprof = AP_RPROF(ap)
+	fnd = AP_PFIND(ap)
+
+	switch (param) {
+	case RPFWHM:
+	    AP_RPFWHM(rprof) = rval
+	case INORM:
+	    AP_INORM(rprof) = rval
+	case TNORM:
+	    AP_TINORM(rprof) = rval
+	case DNORM:
+	    AP_DNORM(rprof) = rval
+	case RPXCUR:
+	    AP_RPXCUR(rprof) = rval
+	case RPYCUR:
+	    AP_RPYCUR(rprof) = rval
+	case ORPXCUR:
+	    AP_ORPXCUR(rprof) = rval
+	case ORPYCUR:
+	    AP_ORPYCUR(rprof) = rval
+	case RPRADIUS:
+	    AP_RPRADIUS(rprof) = rval
+	    AP_RPNPTS(rprof) = int (AP_RPRADIUS(rprof) / AP_RPSTEP(rprof)) + 1
+	    call realloc (AP_RPDIST(rprof), AP_RPNPTS(rprof), TY_REAL)
+	    call realloc (AP_INTENSITY(rprof), AP_RPNPTS(rprof), TY_REAL)
+	    call realloc (AP_DINTENSITY(rprof), AP_RPNPTS(rprof), TY_REAL)
+	    call realloc (AP_TINTENSITY(rprof), AP_RPNPTS(rprof), TY_REAL)
+	case RPSTEP:
+	    AP_RPSTEP(rprof) = rval
+	    AP_RPNPTS(rprof) = int (AP_RPRADIUS(rprof) / AP_RPSTEP(rprof)) + 1
+	    call realloc (AP_RPDIST(rprof), AP_RPNPTS(rprof), TY_REAL)
+	    call realloc (AP_INTENSITY(rprof), AP_RPNPTS(rprof), TY_REAL)
+	    call realloc (AP_DINTENSITY(rprof), AP_RPNPTS(rprof), TY_REAL)
+	    call realloc (AP_TINTENSITY(rprof), AP_RPNPTS(rprof), TY_REAL)
+	case RPKSIGMA:
+	    AP_RPKSIGMA(rprof) = rval
+	case PYZMAG:
+	    AP_PYZMAG(ply) = rval
+	case PYMAG:
+	    AP_PYMAG(ply) = rval
+	case PYMAGERR:
+	    AP_PYMAGERR(ply) = rval
+	case PYX:
+	    AP_PYX(ply) = rval
+	case PYY:
+	    AP_PYY(ply) = rval
+	case PYMINRAD:
+	    AP_PYMINRAD(ply) = rval
+	case PYCX:
+	    AP_PYCX(ply) = rval
+	case PYCY:
+	    AP_PYCY(ply) = rval
+	case OPYCX:
+	    AP_OPYCX(ply) = rval
+	case OPYCY:
+	    AP_OPYCY(ply) = rval
+	case PYXMEAN:
+	    AP_PYXMEAN(ply) = rval
+	case PYYMEAN:
+	    AP_PYYMEAN(ply) = rval
+	case OPYXMEAN:
+	    AP_OPYXMEAN(ply) = rval
+	case OPYYMEAN:
+	    AP_OPYYMEAN(ply) = rval
+	case SKYSIGMA:
+	    AP_SKYSIGMA(nse) = rval
+	case EPADU:
+	    AP_EPADU(nse) = rval
+	case READNOISE:
+	    AP_READNOISE(nse) = rval
+	case THRESHOLD:
+	    AP_THRESHOLD(fnd) = rval
+	case RATIO:
+	    AP_RATIO(fnd) = rval
+	case THETA:
+	    AP_THETA(fnd) = rval
+	case NSIGMA:
+	    AP_NSIGMA(fnd) = rval
+	case SHARPLO:
+	    AP_SHARPLO(fnd) = rval
+	case SHARPHI:
+	    AP_SHARPHI(fnd) = rval
+	case ROUNDLO:
+	    AP_ROUNDLO(fnd) = rval
+	case ROUNDHI:
+	    AP_ROUNDHI(fnd) = rval
+	default:
+	    call error (0, "APSETR: Unknown apphot real parameter")
+	}
+end
+
+
+# AP2SETD -- Procedure to set a double apphot parameter.
+
+procedure ap2setd (ap, param, dval)
+
+pointer	ap		# pointer to apphot structure
+int	param		# parameter
+double	dval		# double value
+
+pointer	nse, ply, rprof, fnd
+
+begin
+	nse = AP_NOISE(ap)
+	ply = AP_POLY(ap)
+	rprof = AP_RPROF(ap)
+	fnd = AP_PFIND(ap)
+
+	switch (param) {
+	case PYNPIX:
+	    AP_PYNPIX(ply) = dval
+	case PYFLUX:
+	    AP_PYFLUX(ply) = dval
+	default:
+	    call error (0, "APSETD: Unknown apphot double parameter")
+	}
+end
diff --git a/noao/digiphot/apphot/aplib/apshowplot.x b/noao/digiphot/apphot/aplib/apshowplot.x
new file mode 100644
index 00000000..ed188d52
--- /dev/null
+++ b/noao/digiphot/apphot/aplib/apshowplot.x
@@ -0,0 +1,83 @@
+include "../lib/apphot.h"
+
+define	RADIUS	15.0
+define	CRADIUS	 5
+
+# AP_SHOWPLOT -- Plot a radial profile of a star.
+
+int	procedure ap_showplot (ap, im, wx, wy, gd, xcenter, ycenter, rmin,
+	rmax, imin, imax)
+
+pointer	ap			# pointer to the apphot structure
+pointer	im			# pointer to the image
+real	wx, wy			# the cursor coordinates
+pointer	gd			# pointer to the graphics stream
+real	xcenter, ycenter	# the centered coordinates
+real	rmin, rmax		# minimum and maximum radius
+real	imin, imax		# minimum and maximum intensity
+
+real	radius, xc, yc, xold, yold
+pointer	sp, r, skypix, coords, index, str, gt
+int	niter, lenbuf, nx, ny, nsky
+
+real	apstatr()
+pointer	ap_gtinit()
+int	ap_gvrad(), apstati(), ap_skypix()
+
+begin
+	call gclear (gd)
+	call gflush (gd)
+
+	# Set the pixel extraction parameters.
+	lenbuf = ap_gvrad (RADIUS, radius)
+
+	# Initialize.
+	call smark (sp)
+	call salloc (r, lenbuf, TY_REAL)
+	call salloc (skypix, lenbuf, TY_REAL)
+	call salloc (coords, lenbuf, TY_INT)
+	call salloc (index, lenbuf, TY_INT)
+	call salloc (str, SZ_LINE, TY_CHAR)
+
+	# Center the star.
+	niter = 0
+	xold = wx
+	yold = wy
+	repeat {
+	    call ap_ictr (im, xold, yold, CRADIUS, apstati (ap, POSITIVE),
+	        xcenter, ycenter)
+	    niter = niter + 1
+	    if (abs (xcenter - xold) <= 1.0 && abs (ycenter - yold) <= 1.0)
+		break
+	    xold = xcenter
+	    yold = ycenter
+	} until (niter >= 3)
+
+	# Fetch the pixels.
+	nsky = ap_skypix (im, xcenter, ycenter, 0.0, radius, Memr[skypix],
+	    Memi[coords], xc, yc, nx, ny)
+	if (nsky <= 0) {
+	    call sfree (sp)
+	    return (ERR)
+	}
+	call ap_index (Memi[index], nsky)
+
+	# Compute the radius and intensity values.
+	call ap_xytor (Memi[coords], Memi[index], Memr[r], nsky, xc, yc, nx)
+	call alimr (Memr[r], nsky, rmin, rmax)
+	call alimr (Memr[skypix], nsky, imin, imax)
+
+	# Plot the radial profiles.
+	#call apstats (ap, IMNAME, Memc[str], SZ_FNAME)
+	call apstats (ap, IMROOT, Memc[str], SZ_FNAME)
+	call ap_ltov (im, xcenter, ycenter, xc, yc, 1)
+	gt = ap_gtinit (Memc[str], xc, yc)
+	call ap_rset (gd, gt, 0.0, rmax, imin, imax, apstatr (ap, SCALE))
+	call ap_plotrad (gd, gt, Memr[r], Memr[skypix], nsky, "plus")
+
+	# Cleanup.
+	call ap_gtfree (gt)
+	call sfree (sp)
+
+	return (OK)
+end
diff --git a/noao/digiphot/apphot/aplib/apstat.x b/noao/digiphot/apphot/aplib/apstat.x
new file mode 100644
index 00000000..9ddc98ca
--- /dev/null
+++ b/noao/digiphot/apphot/aplib/apstat.x
@@ -0,0 +1,77 @@
+define	MAXERR1		500
+define	MAXERR2		1000
+
+# APSTATS -- Procedure to fetch an apphot string parameter.
+
+procedure apstats (ap, param, str, maxch)
+
+pointer	ap		# pointer to apphot structure
+int	param		# parameter
+char	str[ARB]	# string
+int	maxch		# maximum number of characters
+
+begin
+	if (param <= MAXERR1)
+	    call ap1stats (ap, param, str, maxch)
+	else if (param <= MAXERR2)
+	    call ap2stats (ap, param, str, maxch)
+	else
+	    call error (0, "APSTATS: Unknown apphot string parameter")
+end
+
+
+# APSTATI -- Procedure to set an integer apphot parameter.
+
+int procedure apstati (ap, param)
+
+pointer	ap		# pointer to apphot structure
+int	param		# parameter
+
+int	ap1stati(), ap2stati()
+
+begin
+	if (param <= MAXERR1)
+	    return (ap1stati (ap, param))
+	else if (param <= MAXERR2)
+	    return (ap2stati (ap, param))
+	else
+	    call error (0, "APSTATI: Unknown apphot integer parameter")
+end
+
+
+# APSTATR -- Procedure to set a real apphot parameter.
+
+real procedure apstatr (ap, param)
+
+pointer	ap		# pointer to apphot structure
+int	param		# parameter
+
+real	ap1statr(), ap2statr()
+
+begin
+	if (param <= MAXERR1)
+	    return (ap1statr (ap, param))
+	else if (param <= MAXERR2)
+	    return (ap2statr (ap, param))
+	else
+	    call error (0, "APSTATR: Unknown apphot real parameter")
+end
+
+
+# APSTATD -- Procedure to set a double apphot parameter.
+
+double procedure apstatd (ap, param)
+
+pointer	ap		# pointer to apphot structure
+int	param		# parameter
+
+double	ap1statd(), ap2statd()
+
+begin
+	if (param <= MAXERR1)
+	    return (ap1statd (ap, param))
+	else if (param <= MAXERR2)
+	    return (ap2statd (ap, param))
+	else
+	    call error (0, "APSTATD: Unknown apphot double parameter")
+end
diff --git a/noao/digiphot/apphot/aplib/apstat1.x b/noao/digiphot/apphot/aplib/apstat1.x
new file mode 100644
index 00000000..0df220ae
--- /dev/null
+++ b/noao/digiphot/apphot/aplib/apstat1.x
@@ -0,0 +1,316 @@
+include "../lib/apphotdef.h"
+include "../lib/apphot.h"
+include "../lib/centerdef.h"
+include "../lib/center.h"
+include "../lib/fitskydef.h"
+include "../lib/fitsky.h"
+include "../lib/photdef.h"
+include "../lib/phot.h"
+include "../lib/fitpsfdef.h"
+include "../lib/fitpsf.h"
+
+# AP1STATS -- Procedure to fetch an apphot string parameter.
+
+procedure ap1stats (ap, param, str, maxch)
+
+pointer	ap		# pointer to apphot structure
+int	param		# parameter
+char	str[ARB]	# string
+int	maxch		# maximum number of characters
+
+pointer	cen, sky, phot, psf
+
+begin
+	cen = AP_PCENTER(ap)
+	sky = AP_PSKY(ap)
+	phot = AP_PPHOT(ap)
+	psf = AP_PPSF(ap)
+
+	switch (param) {
+	case IMNAME:
+	    call strcpy (AP_IMNAME(ap), str, maxch)
+	case IMROOT:
+	    call strcpy (AP_IMROOT(ap), str, maxch)
+	case CLNAME:
+	    call strcpy (AP_CLNAME(ap), str, maxch)
+	case CLROOT:
+	    call strcpy (AP_CLROOT(ap), str, maxch)
+	case PLOTFILE:
+	    call strcpy (AP_PLOTFILE(ap), str, maxch)
+	case OUTNAME:
+	    call strcpy (AP_OUTNAME(ap), str, maxch)
+	case EXPOSURE:
+	    call strcpy (AP_EXPOSURE(ap), str, maxch)
+	case AIRMASS:
+	    call strcpy (AP_AIRMASS(ap), str, maxch)
+	case FILTER:
+	    call strcpy (AP_FILTER(ap), str, maxch)
+	case FILTERID:
+	    call strcpy (AP_FILTERID(ap), str, maxch)
+	case OBSTIME:
+	    call strcpy (AP_OBSTIME(ap), str, maxch)
+	case OTIME:
+	    call strcpy (AP_OTIME(ap), str, maxch)
+
+	case CSTRING:
+	    call strcpy (AP_CSTRING(cen), str, maxch)
+
+	case SSTRING:
+	    call strcpy (AP_SSTRING(sky), str, maxch)
+
+	case APSTRING:
+	    call strcpy (AP_APSTRING(phot), str, maxch)
+	case APERTS:
+	    call strcpy (AP_APSTRING(phot), str, maxch)
+	case PWSTRING:
+	    call strcpy (AP_PWSTRING(phot), str, maxch)
+
+	case PSFSTRING:
+	    call strcpy (AP_PSFSTRING(psf), str, maxch)
+
+	default:
+	    call error (0, "APSTATS: Unknown apphot string parameter")
+	}
+end
+
+
+# AP1STATI -- Procedure to set an integer apphot parameter.
+
+int procedure ap1stati (ap, param)
+
+pointer	ap		# pointer to apphot structure
+int	param		# parameter
+
+pointer cen, sky, phot, psf
+
+begin
+	cen = AP_PCENTER(ap)
+	sky = AP_PSKY(ap)
+	phot = AP_PPHOT(ap)
+	psf = AP_PPSF(ap)
+
+	switch (param) {
+	case POSITIVE:
+	    return (AP_POSITIVE(ap))
+	case WCSIN:
+	    return (AP_WCSIN(ap))
+	case WCSOUT:
+	    return (AP_WCSOUT(ap))
+	case MW:
+	    return (AP_MW(ap))
+	case CTIN:
+	    return (AP_CTIN(ap))
+	case CTOUT:
+	    return (AP_CTOUT(ap))
+
+	case CENTERFUNCTION:
+	    return (AP_CENTERFUNCTION(cen))
+	case CLEAN:
+	    return (AP_CLEAN(cen))
+	case CMAXITER:
+	    return (AP_CMAXITER(cen))
+
+	case SKYFUNCTION:
+	    return (AP_SKYFUNCTION(sky))
+	case SMAXITER:
+	    return (AP_SMAXITER(sky))
+	case SNREJECT:
+	    return (AP_SNREJECT(sky))
+	case SMOOTH:
+	    return (AP_SMOOTH(sky))
+	case NSKY:
+	    return (AP_NSKY(sky))
+	case NSKY_REJECT:
+	    return (AP_NSKY_REJECT(sky))
+
+	case NAPERTS:
+	    return (AP_NAPERTS(phot))
+	case PWEIGHTS:
+	    return (AP_PWEIGHTS(phot))
+
+	case MAXNPARS:
+	    return (AP_MAXNPARS(psf))
+	case NPARS:
+	    return (AP_PSFNPARS(psf))
+	case PMAXITER:
+	    return (AP_PMAXITER(psf))
+	case PSFUNCTION:
+	    return (AP_PSFUNCTION(psf))
+	case PNREJECT:
+	    return (AP_PNREJECT(psf))
+
+	default:
+	    call error (0, "APSTATI: Unknown apphot integer parameter")
+	}
+end
+
+
+# AP1STATR -- Procedure to set a real apphot parameter.
+
+real procedure ap1statr (ap, param)
+
+pointer	ap		# pointer to apphot structure
+int	param		# parameter
+
+pointer	cen, sky, phot, psf
+
+begin
+	cen = AP_PCENTER(ap)
+	sky = AP_PSKY(ap)
+	phot = AP_PPHOT(ap)
+	psf = AP_PPSF(ap)
+
+	switch (param) {
+
+	case FWHMPSF:
+	    return (AP_FWHMPSF(ap))
+	case SCALE:
+	    return (AP_SCALE(ap))
+	case WX:
+	    return (AP_WX(ap))
+	case WY:
+	    return (AP_WY(ap))
+	case ITIME:
+	    return (AP_ITIME(ap))
+	case CWX:
+	    return (AP_CWX(ap))
+	case CWY:
+	    return (AP_CWY(ap))
+	case DATAMIN:
+	    return (AP_DATAMIN(ap))
+	case DATAMAX:
+	    return (AP_DATAMAX(ap))
+	case XAIRMASS:
+	    return (AP_XAIRMASS(ap))
+
+	case CDATALIMIT:
+	    return (AP_CDATALIMIT(cen))
+	case XSHIFT:
+	    return (AP_XSHIFT(cen))
+	case YSHIFT:
+	    return (AP_YSHIFT(cen))
+	case OXSHIFT:
+	    return (AP_OXSHIFT(cen))
+	case OYSHIFT:
+	    return (AP_OYSHIFT(cen))
+	case CXCUR:
+	    return (AP_CXCUR(cen))
+	case CYCUR:
+	    return (AP_CYCUR(cen))
+	case CAPERT:
+	    return (AP_CAPERT(cen))
+	case CTHRESHOLD:
+	    return (AP_CTHRESHOLD(cen))
+	case MAXSHIFT:
+	    return (AP_MAXSHIFT(cen))
+	case MINSNRATIO:
+	    return (AP_MINSNRATIO(cen))
+	case RCLEAN:
+	    return (AP_RCLEAN(cen))
+	case RCLIP:
+	    return (AP_RCLIP(cen))
+	case SIGMACLEAN:
+	    return (AP_SIGMACLEAN(cen))
+
+	case OXINIT:
+	    return (AP_OXINIT(cen))
+	case OYINIT:
+	    return (AP_OYINIT(cen))
+	case XCENTER:
+	    return (AP_XCENTER(cen))
+	case YCENTER:
+	    return (AP_YCENTER(cen))
+	case OXCENTER:
+	    return (AP_OXCENTER(cen))
+	case OYCENTER:
+	    return (AP_OYCENTER(cen))
+	case XERR:
+	    return (AP_XERR(cen))
+	case YERR:
+	    return (AP_YERR(cen))
+
+	case SXCUR:
+	    return (AP_SXCUR(sky))
+	case SYCUR:
+	    return (AP_SYCUR(sky))
+	case OSXCUR:
+	    return (AP_OSXCUR(sky))
+	case OSYCUR:
+	    return (AP_OSYCUR(sky))
+	case ANNULUS:
+	    return (AP_ANNULUS(sky))
+	case DANNULUS:
+	    return (AP_DANNULUS(sky))
+	case K1:
+	    return (AP_K1(sky))
+	case SLOREJECT:
+	    return (AP_SLOREJECT(sky))
+	case SHIREJECT:
+	    return (AP_SHIREJECT(sky))
+	case SLOCLIP:
+	    return (AP_SLOCLIP(sky))
+	case SHICLIP:
+	    return (AP_SHICLIP(sky))
+	case BINSIZE:
+	    return (AP_BINSIZE(sky))
+	case RGROW:
+	    return (AP_RGROW(sky))
+	case SKY_BACKGROUND:
+	    return (AP_SKYBACKGROUND(sky))
+	case SKY_MODE:
+	    return (AP_SKY_MODE(sky))
+	case SKY_SIGMA:
+	    return (AP_SKY_SIG(sky))
+	case SKY_SKEW:
+	    return (AP_SKY_SKEW(sky))
+
+	case PXCUR:
+	    return (AP_PXCUR(phot))
+	case PYCUR:
+	    return (AP_PYCUR(phot))
+	case OPXCUR:
+	    return (AP_OPXCUR(phot))
+	case OPYCUR:
+	    return (AP_OPYCUR(phot))
+	case ZMAG:
+	    return (AP_ZMAG(phot))
+
+	case PSFAPERT:
+	    return (AP_PSFAPERT(psf))
+	case PK2:
+	    return (AP_PK2(psf))
+	case PFXCUR:
+	    return (AP_PFXCUR(psf))
+	case PFYCUR:
+	    return (AP_PFYCUR(psf))
+	case OPFXCUR:
+	    return (AP_OPFXCUR(psf))
+	case OPFYCUR:
+	    return (AP_OPFYCUR(psf))
+
+	default:
+	    call error (0, "APSTATR: Unknown apphot real parameter")
+	}
+end
+
+
+# AP1STATD -- Procedure to set a double apphot parameter.
+
+double procedure ap1statd (ap, param)
+
+pointer	ap		# pointer to apphot structure
+int	param		# parameter
+
+pointer	cen, sky, phot, psf
+
+begin
+	cen = AP_PCENTER(ap)
+	sky = AP_PSKY(ap)
+	phot = AP_PPHOT(ap)
+	psf = AP_PPSF(ap)
+
+	switch (param) {
+	default:
+	    call error (0, "APSTATD: Unknown apphot double parameter")
+	}
+end
diff --git a/noao/digiphot/apphot/aplib/apstat2.x b/noao/digiphot/apphot/aplib/apstat2.x
new file mode 100644
index 00000000..032b19e5
--- /dev/null
+++ b/noao/digiphot/apphot/aplib/apstat2.x
@@ -0,0 +1,215 @@
+include "../lib/apphotdef.h"
+include "../lib/apphot.h"
+include "../lib/displaydef.h"
+include "../lib/display.h"
+include "../lib/noisedef.h"
+include "../lib/noise.h"
+include "../lib/polyphotdef.h"
+include "../lib/polyphot.h"
+include "../lib/radprofdef.h"
+include "../lib/radprof.h"
+include "../lib/finddef.h"
+include "../lib/find.h"
+
+# AP2STATS -- Procedure to fetch an apphot string parameter.
+
+procedure ap2stats (ap, param, str, maxch)
+
+pointer	ap		# pointer to apphot structure
+int	param		# parameter
+char	str[ARB]	# string
+int	maxch		# maximum number of characters
+
+pointer	 nse, ply
+
+begin
+	nse = AP_NOISE(ap)
+	ply = AP_POLY(ap)
+
+	switch (param) {
+	case PYNAME:
+	    call strcpy (AP_PYNAME(ply), str, maxch)
+	case PYROOT:
+	    call strcpy (AP_PYROOT(ply), str, maxch)
+	case GAIN:
+	    call strcpy (AP_GAIN(nse), str, maxch)
+	case NSTRING:
+	    call strcpy (AP_NSTRING(nse), str, maxch)
+	case CCDREAD:
+	    call strcpy (AP_CCDREAD(nse), str, maxch)
+	default:
+	    call error (0, "APSTATS: Unknown apphot string parameter")
+	}
+end
+
+
+# AP2STATI -- Procedure to set an integer apphot parameter.
+
+int procedure ap2stati (ap, param)
+
+pointer	ap		# pointer to apphot structure
+int	param		# parameter
+
+pointer dsp, nse, ply, rprof
+
+begin
+	dsp = AP_PDISPLAY(ap)
+	nse = AP_NOISE(ap)
+	ply = AP_POLY(ap)
+	rprof = AP_RPROF(ap)
+
+	switch (param) {
+	case RPORDER:
+	    return (AP_RPORDER(rprof))
+	case RPNREJECT:
+	    return (AP_RPNREJECT(rprof))
+	case PYNVER:
+	    return (AP_PYNVER(ply))
+	case PYBADPIX:
+	    return (AP_PYBADPIX(ply))
+	case MKSKY:
+	    return (AP_MKSKY(dsp))
+	case MKCENTER:
+	    return (AP_MKCENTER(dsp))
+	case MKAPERT:
+	    return (AP_MKAPERT(dsp))
+	case MKPOLYGON:
+	    return (AP_MKPOLYGON(dsp))
+	case MKDETECTIONS:
+	    return (AP_MKDETECTIONS(dsp))
+	case NOISEFUNCTION:
+	    return (AP_NOISEFUNCTION(nse))
+	case MKPSFBOX:
+	    return (AP_MKPSFBOX(dsp))
+	case RADPLOTS:
+	    return (AP_RADPLOTS(dsp))
+	case RPNPTS:
+	    return (AP_RPNPTS(rprof))
+	case RPNDATA:
+	    return (AP_RPNDATA(rprof))
+	case RPNDATAREJ:
+	    return (AP_RPNDATAREJ(rprof))
+	default:
+	    call error (0, "APSTATI: Unknown apphot integer parameter")
+	}
+end
+
+
+# AP2STATR -- Procedure to set a real apphot parameter.
+
+real procedure ap2statr (ap, param)
+
+pointer	ap		# pointer to apphot structure
+int	param		# parameter
+
+pointer	nse, ply, rprof, fnd
+
+begin
+	nse = AP_NOISE(ap)
+	ply = AP_POLY(ap)
+	rprof = AP_RPROF(ap)
+	fnd = AP_PFIND(ap)
+
+	switch (param) {
+	case RPFWHM:
+	    return (AP_RPFWHM(rprof))
+	case INORM:
+	    return (AP_INORM(rprof))
+	case TNORM:
+	    return (AP_TINORM(rprof))
+	case DNORM:
+	    return (AP_DNORM(rprof))
+	case RPXCUR:
+	    return (AP_RPXCUR(rprof))
+	case RPYCUR:
+	    return (AP_RPYCUR(rprof))
+	case ORPXCUR:
+	    return (AP_ORPXCUR(rprof))
+	case ORPYCUR:
+	    return (AP_ORPYCUR(rprof))
+	case RPRADIUS:
+	    return (AP_RPRADIUS(rprof))
+	case RPSTEP:
+	    return (AP_RPSTEP(rprof))
+	case RPKSIGMA:
+	    return (AP_RPKSIGMA(rprof))
+	case PYZMAG:
+	    return (AP_PYZMAG(ply))
+	case PYMAG:
+	    return (AP_PYMAG(ply))
+	case PYMAGERR:
+	    return (AP_PYMAGERR(ply))
+	case PYX:
+	    return (AP_PYX(ply))
+	case PYY:
+	    return (AP_PYY(ply))
+	case PYMINRAD:
+	    return (AP_PYMINRAD(ply))
+	case PYXMEAN:
+	    return (AP_PYXMEAN(ply))
+	case PYYMEAN:
+	    return (AP_PYYMEAN(ply))
+	case OPYXMEAN:
+	    return (AP_OPYXMEAN(ply))
+	case OPYYMEAN:
+	    return (AP_OPYYMEAN(ply))
+	case PYCX:
+	    return (AP_PYCX(ply))
+	case PYCY:
+	    return (AP_PYCY(ply))
+	case OPYCX:
+	    return (AP_OPYCX(ply))
+	case OPYCY:
+	    return (AP_OPYCY(ply))
+	case SKYSIGMA:
+	    return (AP_SKYSIGMA(nse))
+	case EPADU:
+	    return (AP_EPADU(nse))
+	case READNOISE:
+	    return (AP_READNOISE(nse))
+	case THRESHOLD:
+	    return (AP_THRESHOLD(fnd))
+	case RATIO:
+	    return (AP_RATIO(fnd))
+	case THETA:
+	    return (AP_THETA(fnd))
+	case NSIGMA:
+	    return (AP_NSIGMA(fnd))
+	case SHARPLO:
+	    return (AP_SHARPLO(fnd))
+	case SHARPHI:
+	    return (AP_SHARPHI(fnd))
+	case ROUNDLO:
+	    return (AP_ROUNDLO(fnd))
+	case ROUNDHI:
+	    return (AP_ROUNDHI(fnd))
+	default:
+	    call error (0, "APSTATR: Unknown apphot real parameter")
+	}
+end
+
+
+# AP2STATD -- Procedure to set a double apphot parameter.
+
+double procedure ap2statd (ap, param)
+
+pointer	ap		# pointer to apphot structure
+int	param		# parameter
+
+pointer	nse, ply, rprof, fnd
+
+begin
+	nse = AP_NOISE(ap)
+	ply = AP_POLY(ap)
+	rprof = AP_RPROF(ap)
+	fnd = AP_PFIND(ap)
+
+	switch (param) {
+	case PYNPIX:
+	    return (AP_PYNPIX(ply))
+	case PYFLUX:
+	    return (AP_PYFLUX(ply))
+	default:
+	    call error (0, "APSTATD: Unknown apphot double parameter")
+	}
+end
diff --git a/noao/digiphot/apphot/aplib/apverify1.x b/noao/digiphot/apphot/aplib/apverify1.x
new file mode 100644
index 00000000..1ecd04b6
--- /dev/null
+++ b/noao/digiphot/apphot/aplib/apverify1.x
@@ -0,0 +1,582 @@
+include <math.h>
+include "../lib/apphot.h"
+include "../lib/noise.h"
+include "../lib/center.h"
+include "../lib/fitsky.h"
+include "../lib/phot.h"
+
+# AP_GVRAD -- Verify or get the radius of the extraction box.
+
+int procedure ap_gvrad (defradius, radius)
+
+real	defradius		# the default radius
+real	radius			# the output radius
+
+int	lenbuf
+int	scan(), nscan()
+
+begin
+	call printf (
+	    "Radius of extraction box in pixels (%4.1f) (CR  or value): ")
+	    call pargr (defradius)
+	call flush (STDOUT)
+
+	if (scan () == EOF)
+	    radius = defradius
+	else {
+	    call gargr (radius)
+	    if (nscan () < 1)
+	        radius = defradius
+	}
+	lenbuf = PI * radius * (radius + 1.0)
+
+	return (lenbuf)
+end
+
+
+# AP_VFWHMPSF -- Verify the full width maximum of the psf.
+
+real procedure ap_vfwhmpsf (ap)
+
+pointer	ap		# pointer to the apphot structure
+
+real	scale, fwhmpsf
+int	scan(), nscan()
+real	apstatr()
+
+begin
+	scale = apstatr (ap, SCALE) 
+	call printf ("FWHM of features in scale units (%g) (CR or value): ")
+	    call pargr (apstatr (ap, FWHMPSF))
+	call flush (STDOUT)
+
+	# Confirm the fwhmpsf.
+	if (scan() == EOF)
+	    fwhmpsf = apstatr (ap, FWHMPSF)
+	else {
+	    call gargr (fwhmpsf)
+	    if (nscan () != 1)
+	        fwhmpsf = apstatr (ap, FWHMPSF)
+	}
+
+	call printf ("\tNew FWHM of features: %g scale units  %g pixels\n")
+	    call pargr (fwhmpsf)
+	    call pargr (scale * fwhmpsf)
+	call apsetr (ap, FWHMPSF, fwhmpsf)
+
+	return (fwhmpsf)
+end
+
+
+# AP_VDATAMIN-- Verify the minimum good data value.
+
+real procedure ap_vdatamin (ap)
+
+pointer	ap		# pointer to the apphot structure
+
+real	datamin
+int	scan(), nscan()
+real	apstatr()
+
+begin
+	# Confirm the threshold parameter.
+	call printf ("Minimum good data value (%g) (CR or value): ")
+	    call pargr (apstatr (ap, DATAMIN))
+	call flush (STDOUT)
+	if (scan() == EOF)
+	    datamin = apstatr (ap, DATAMIN)
+	else {
+	    call gargr (datamin)
+	    if (nscan () != 1)
+	        datamin = apstatr (ap, DATAMIN)
+	}
+
+	call printf ("\tNew minimum good data value: %g counts\n")
+	    call pargr (datamin)
+	call apsetr (ap, DATAMIN, datamin)
+
+	return (datamin)
+end
+
+
+# AP_VDATAMAX-- Verify the maximum good data value.
+
+real procedure ap_vdatamax (ap)
+
+pointer	ap		# pointer to the apphot structure
+
+real	datamax
+int	scan(), nscan()
+real	apstatr()
+
+begin
+	# Confirm the threshold parameter.
+	call printf ("Maximum good data value (%g) (CR or value): ")
+	    call pargr (apstatr (ap, DATAMAX))
+	call flush (STDOUT)
+	if (scan() == EOF)
+	    datamax = apstatr (ap, DATAMAX)
+	else {
+	    call gargr (datamax)
+	    if (nscan () != 1)
+	        datamax = apstatr (ap, DATAMAX)
+	}
+
+	call printf ("\tNew maximum good data value: %g counts\n")
+	    call pargr (datamax)
+	call apsetr (ap, DATAMAX, datamax)
+
+	return (datamax)
+end
+
+
+# AP_VSIGMA -- Verify the standard deviation of the sky
+
+real procedure ap_vsigma (ap)
+
+pointer	ap		# pointer to the apphot structure
+
+real	skysigma
+int	scan(), nscan()
+real	apstatr()
+
+begin
+	# Confirm the sky sigma parameter.
+	call printf (
+	    "Standard deviation of background in counts (%g) (CR or value): ")
+	    call pargr (apstatr (ap, SKYSIGMA))
+	call flush (STDOUT)
+	if (scan() == EOF)
+	    skysigma = apstatr (ap, SKYSIGMA)
+	else {
+	    call gargr (skysigma)
+	    if (nscan () != 1)
+	        skysigma = apstatr (ap, SKYSIGMA)
+	}
+
+	call printf ("\tNew standard deviation of background: %g counts\n")
+	    call pargr (skysigma)
+	call apsetr (ap, SKYSIGMA, skysigma)
+
+	return (skysigma)
+end
+
+
+# AP_VCSTRING -- Verify the centering string.
+
+procedure ap_vcstring (ap, str, maxch)
+
+pointer	ap		# pointer to the apphot strucuture
+char	str[ARB]	# output string
+int	maxch		# maximum number of characters
+
+int	cfunc
+int	scan(), strdic(), nscan()
+
+begin
+	# Print the old centering algorithm.
+	call apstats (ap, CSTRING, str, maxch)
+	call printf ("Centering algorithm (%s) (CR or value): ")
+	    call pargstr (str)
+	call flush (STDOUT)
+
+	# Confirm the centering algorithm.
+	if (scan() != EOF) {
+	    call gargwrd (str, maxch)
+	    cfunc = strdic (str, str, maxch, CFUNCS)
+	    if (nscan () == 1 && cfunc > 0) {
+		call apseti (ap, CENTERFUNCTION, cfunc)
+		call apsets (ap, CSTRING, str)
+	    }
+	}
+
+	# Print the new result.
+	call apstats (ap, CSTRING, str, maxch)
+	call printf ("\tNew centering algorithm: %s\n")
+	    call pargstr (str)
+end
+
+
+# AP_VCAPERT -- Verify the centering aperture.
+
+real procedure ap_vcapert (ap)
+
+pointer	ap		# pointert to the apphot strucuture
+
+real	scale, capert
+int	scan(), nscan()
+real	apstatr()
+
+begin
+	# Get the apphot scale factor.
+	scale = apstatr (ap, SCALE)
+
+	# Print the old centering value.
+	call printf ("Centering box width in scale units (%g) (CR or value): ")
+	    call pargr (2.0 * apstatr (ap, CAPERT))
+	call flush (STDOUT)
+
+	# Get the new centering value.
+	if (scan() == EOF)
+	    capert = 2.0 * apstatr (ap, CAPERT)
+	else {
+	    call gargr (capert)
+	    if (nscan () != 1)
+	        capert = 2.0 * apstatr (ap, CAPERT)
+	}
+
+	# Type the new value.
+	call apsetr (ap, CAPERT, capert / 2.0) 
+	call printf ("\tNew centering box width: %g scale units  %g pixels\n")
+	    call pargr (capert)
+	    call pargr (scale * capert)
+
+	return (capert / 2.0)
+end
+
+
+# AP_VCTHRESHOLD -- Verify the centering threshold parameter.
+
+real procedure ap_vcthreshold (ap)
+
+pointer	ap		# pointer to the apphot structure
+
+real	skysigma, cthreshold
+int	scan(), nscan()
+real	apstatr()
+
+begin
+	# Get the sky sigma.
+	skysigma = apstatr (ap, SKYSIGMA)
+
+	# Print the old centering threshold.
+	call printf (
+	"Centering threshold in sigma above data minimum (%g) (CR or value): ")
+	    call pargr (apstatr (ap, CTHRESHOLD))
+	call flush (STDOUT)
+
+	# Confirm the centering threshold parameter.
+	if (scan() == EOF)
+	    cthreshold = apstatr (ap, CTHRESHOLD)
+	else {
+	    call gargr (cthreshold)
+	    if (nscan () != 1)
+	        cthreshold = apstatr (ap, CTHRESHOLD)
+	}
+
+	# Print the new centering threshold.
+	call apsetr (ap, CTHRESHOLD, cthreshold) 
+	call printf ("\tNew centering threshold: %g skysigma  %g counts\n")
+	    call pargr (cthreshold)
+	if (IS_INDEFR(skysigma))
+	    call pargr (INDEFR)
+	else
+	    call pargr (cthreshold * skysigma)
+
+	return (cthreshold)
+end
+
+
+# AP_VRCLEAN -- Verify the cleaning radius
+
+real procedure ap_vrclean (ap)
+
+pointer	ap		# pointer to the apphot structure
+
+real	scale, rclean
+int	scan(), nscan()
+real	apstatr()
+
+begin
+	# Confirm the cleaning radius.
+	scale = apstatr (ap, SCALE) 
+	call printf ("Cleaning radius in scale units (%g) (CR or value): ")
+	    call pargr (apstatr (ap, RCLEAN))
+	call flush (STDOUT)
+	if (scan() == EOF)
+	    rclean = apstatr (ap, RCLEAN)
+	else {
+	    call gargr (rclean)
+	    if (nscan () != 1)
+	        rclean = apstatr (ap, RCLEAN)
+	}
+
+	call apsetr (ap, RCLEAN, rclean)
+	call printf ("\tNew cleaning radius: %g scale units  %g pixels\n")
+	    call pargr (rclean)
+	    call pargr (scale * rclean)
+
+	return (rclean)
+end
+
+
+# AP_VRCLIP -- Verify the clipping radius.
+
+real procedure ap_vrclip (ap)
+
+pointer	ap		# pointer to the apphot structure
+
+real	scale, rclip
+int	scan(), nscan()
+real	apstatr()
+
+begin
+	# Confirm the clipping radius.
+	scale = apstatr (ap, SCALE) 
+	call printf ("Clipping radius in scale units (%g) (CR or value): ")
+	    call pargr (apstatr (ap, RCLIP))
+	call flush (STDOUT)
+	if (scan() == EOF)
+	    rclip = apstatr (ap, RCLIP)
+	else {
+	    call gargr (rclip)
+	    if (nscan () != 1)
+	        rclip = apstatr (ap, RCLIP)
+	}
+
+	call apsetr (ap, RCLIP, rclip)
+	call printf ("\tNew FWHM clipping radius: %g scale units  %g pixels\n")
+	    call pargr (rclip)
+	    call pargr (scale * rclip)
+
+	return (rclip)
+end
+
+
+# AP_VSSTRING -- Verify the sky fitting algorithm string.
+
+procedure ap_vsstring (ap, str, maxch)
+
+pointer	ap		# pointer to the apphot structure
+char	str[ARB]	# output string
+int	maxch		# maximum number of characteristics
+
+int	sfunc
+int	scan(), nscan(), strdic()
+
+begin
+	# Print the old salgorithm string.
+	call apstats (ap, SSTRING, str, maxch)
+	call printf ("Sky fitting algorithm (%s) (CR or value): ")
+	    call pargstr (str)
+	call flush (STDOUT)
+
+	# Confirm the sky fitting algorithm.
+	if (scan() != EOF) {
+	    call gargwrd (str, maxch)
+	    sfunc = strdic (str, str, maxch, SFUNCS)
+	    if (nscan () == 1 && sfunc > 0) {
+		call apseti (ap, SKYFUNCTION, sfunc)
+		call apsets (ap, SSTRING, str)
+	    }
+	}
+
+	# Print the new salgorithm string.
+	call apstats (ap, SSTRING, str, maxch)
+	call printf ("\tSky fitting algorithm: %s\n")
+	    call pargstr (str)
+end
+
+
+# AP_VANNULUS -- Verify the inner radius of sky annulus.
+
+real procedure ap_vannulus (ap)
+
+pointer	ap		# pointer to the apphot structure
+
+real	scale, annulus
+int	scan(), nscan()
+real	apstatr()
+
+begin
+	scale = apstatr (ap, SCALE)
+
+	# Print the old inner sky radius value.
+	call printf (
+	"Inner radius of sky annulus in scale units (%g) (CR or value): ")
+            call pargr (apstatr (ap, ANNULUS))
+	call flush (STDOUT)
+
+	# Verify the new value.
+	if (scan () == EOF)
+	    annulus = apstatr (ap, ANNULUS)
+	else {
+	    call gargr (annulus)
+	    if (nscan () != 1)
+	        annulus = apstatr (ap, ANNULUS)
+	}
+
+	# Print the old inner sky radius value.
+	call apsetr (ap, ANNULUS, annulus)
+	call printf (
+	    "\tNew inner radius of sky annulus: %g scale units %g pixels\n")
+	    call pargr (annulus)
+	    call pargr (scale * annulus)
+
+	return (annulus)
+end
+
+
+# AP_VDANNULUS -- Verify the width of the sky annulus.
+
+real procedure ap_vdannulus (ap)
+
+pointer	ap		# pointer to the apphot structure
+
+real	scale, dannulus
+int	scan(), nscan()
+real	apstatr()
+
+begin
+	scale = apstatr (ap, SCALE)
+
+	# Print the old sky annulus width.
+	call printf (
+	    "Width of the sky annulus in scale units (%g) (CR or value): ")
+	    call pargr (apstatr (ap, DANNULUS))
+	call flush (STDOUT)
+
+	# Confirm the width of the sky annulus.
+	if (scan() == EOF)
+	    dannulus = apstatr (ap, DANNULUS)
+	else {
+	    call gargr (dannulus)
+	    if (nscan () != 1)
+	        dannulus = apstatr (ap, DANNULUS)
+	}
+
+	# Print the new sky annulus width.
+	call apsetr (ap, DANNULUS, dannulus)
+	call printf (
+	    "\tNew width of the sky annulus: %g scale units %g pixels\n")
+	    call pargr (dannulus)
+	    call pargr (scale * dannulus)
+
+	return (dannulus)
+end
+
+
+# AP_VRGROW -- Verify the region growing radius
+
+real procedure ap_vrgrow (ap)
+
+pointer	ap		# pointer to the apphot structure
+
+real	scale, rgrow
+int	scan(), nscan()
+real	apstatr()
+
+begin
+	scale = apstatr (ap, SCALE)
+
+	# Print the old region growing radius.
+	call printf (
+	    "Region growing radius in scale units (%g) (CR or value): ")
+	    call pargr (apstatr (ap, RGROW))
+	call flush (STDOUT)
+
+	# Confirm the region growing radius.
+	if (scan() == EOF)
+	    rgrow = apstatr (ap, RGROW)
+	else {
+	    call gargr (rgrow)
+	    if (nscan () != 1)
+	        rgrow = apstatr (ap, RGROW)
+	}
+
+	# Print the region growing radius.
+	call apsetr (ap, RGROW, rgrow)
+	call printf (
+	    "\tNew region growing radius: %g scale units %g pixels\n")
+	    call pargr (rgrow)
+	    call pargr (scale * rgrow)
+
+	return (rgrow)
+end
+
+
+# AP_VAPERTS -- Verify the photometric apertures.
+
+procedure ap_vaperts (ap, str, maxch)
+
+pointer	ap		# pointer to the apphot structure
+char	str[ARB]	# output string
+int	maxch		# maximum number of characters
+
+int	i, naperts
+pointer	sp, aperts
+real	scale
+int	scan(), nscan(), ap_getaperts()
+real	apstatr()
+
+begin
+	call smark (sp)
+	call salloc (aperts, MAX_NAPERTS, TY_REAL)
+
+	scale = apstatr (ap, SCALE)
+
+	# Print the old aperture string.
+	call apstats (ap, APERTS, str, maxch)
+	call printf (
+	"File/list of aperture radii in scale units (%s) (CR or value): ")
+	    call pargstr (str)
+	call flush (STDOUT)
+
+	# Get the new apertures.
+	if (scan() == EOF)
+	    call apstats (ap, APERTS, str, maxch)
+	else {
+	    call gargwrd (str, maxch)
+	    if (nscan () != 1)
+	        call apstats (ap, APERTS, str, maxch)
+	}
+
+	# Print the new apertures.
+	naperts = ap_getaperts (str, Memr[aperts], MAX_NAPERTS)
+	do i = 1, naperts {
+	    call printf ("\tAperture radius %d: %g scale units %g pixels\n")
+		call pargi (i)
+		call pargr (Memr[aperts+i-1])
+		call pargr (scale * Memr[aperts+i-1])
+	}
+
+	call apsets (ap, APERTS, str)
+	call sfree (sp)
+end
+
+
+# AP_VPWSTRING -- Verify the weighting string.
+
+procedure ap_vpwstring (ap, str, maxch)
+
+pointer	ap		# pointer to the apphot structure
+char	str[ARB]	# output string
+int	maxch		# maximum number of characters
+
+int	wfunc
+int	scan(), nscan(), strdic()
+
+begin
+	# Print the old string.
+	call apstats (ap, PWSTRING, str, maxch)
+	call printf ("Weighting algorithm (%s) (CR or value): ")
+	    call pargstr (str)
+	call flush (STDOUT)
+
+	# Get the new value.
+	if (scan() != EOF) {
+	    call gargwrd (str, maxch)
+	    wfunc = strdic (str, str, maxch, PWFUNCS)
+	    if (nscan () == 1 && wfunc > 0) {
+		call apseti (ap, PWEIGHTS, wfunc)
+		call apsets (ap, PWSTRING, str)
+	    }
+	}
+
+	# Print the new value.
+	call apstats (ap, PWSTRING, str, maxch)
+	call printf ("\tNew weighting algorithm: %s\n")
+	    call pargstr (str)
+
+	call apsets (ap, PWSTRING, str)
+end
diff --git a/noao/digiphot/apphot/aplib/apverify2.x b/noao/digiphot/apphot/aplib/apverify2.x
new file mode 100644
index 00000000..b5f02f46
--- /dev/null
+++ b/noao/digiphot/apphot/aplib/apverify2.x
@@ -0,0 +1,188 @@
+include "../lib/apphot.h"
+include "../lib/noise.h"
+include "../lib/find.h"
+include "../lib/fitpsf.h"
+include "../lib/radprof.h"
+
+
+# AP_VTHRESHOLD -- Verify the full detection threshold.
+
+real procedure ap_vthreshold (ap)
+
+pointer	ap		# pointer to the apphot structure
+
+real	skysigma, threshold
+int	scan(), nscan()
+real	apstatr()
+
+begin
+	skysigma = apstatr (ap, SKYSIGMA)
+
+	# Confirm the threshold parameter.
+	call printf (
+	"Detection threshold in sigma (%g) (CR or value): ")
+	    call pargr (apstatr (ap, THRESHOLD))
+	call flush (STDOUT)
+	if (scan() == EOF)
+	    threshold = apstatr (ap, THRESHOLD)
+	else {
+	    call gargr (threshold)
+	    if (nscan () != 1)
+	        threshold = apstatr (ap, THRESHOLD)
+	}
+
+	call printf ("\tNew detection threshold: %g sigma %g counts\n")
+	    call pargr (threshold)
+	call apsetr (ap, THRESHOLD, threshold)
+	if (IS_INDEFR(skysigma))
+	    call pargr (INDEFR)
+	else
+	    call pargr (threshold * skysigma)
+
+	return (threshold)
+end
+
+# AP_VPFSTRING -- Verify the psf fitting function.
+
+procedure ap_vpfstring (ap, str, maxch)
+
+pointer	ap		# pointer to the apphot structure
+char	str[ARB]	# output string
+int	maxch		# maximum number of characters
+
+int	pfunc
+int	scan(), nscan(), strdic()
+
+begin
+	# Print the old string value.
+	call apstats (ap, PSFSTRING, str, maxch)
+	call printf ("Fitting function (%s) (CR or value): ")
+	    call pargstr (str)
+	call flush (STDOUT)
+
+	# Get the new value.
+	if (scan() != EOF) {
+	    call gargwrd (str, maxch)
+	    pfunc = strdic (str, str, maxch, PSFFUNCS)
+	    if (nscan () == 1 && pfunc > 0) {
+		call apseti (ap, PSFUNCTION, pfunc)
+		call apsets (ap, PSFSTRING, str)
+	    }
+	}
+
+	# Print the new value.
+	call apstats (ap, PSFSTRING, str, SZ_LINE)
+	call printf ("\tNew fitting function: %s\n")
+	    call pargstr (str)
+end
+
+
+# AP_VPSFAPERT -- Verify the point spread function fitting aperture.
+
+real procedure ap_vpsfapert (ap)
+
+pointer	ap		# pointer to the apphot strucuture
+
+real	scale, psfapert
+int	scan(), nscan()
+real	apstatr()
+
+begin
+	scale = apstatr (ap, SCALE)
+
+	# Print the old value.
+	call printf ("Fitting box width in scale units (%g) (CR or value): ")
+	    call pargr (2.0 * apstatr (ap, PSFAPERT))
+	call flush (STDOUT)
+
+	# Get the new value.
+	if (scan() == EOF)
+	    psfapert = 2.0 * apstatr (ap, PSFAPERT)
+	else {
+	    call gargr (psfapert)
+	    if (nscan () != 1)
+	        psfapert = 2.0 * apstatr (ap, PSFAPERT)
+	}
+
+	# Print the new  value.
+	call printf ("\tNew fitting box width: %g scale units  %g pixels\n")
+	    call pargr (psfapert)
+	    call pargr (scale 	* psfapert)
+	call apsetr (ap, PSFAPERT, psfapert / 2.0)
+
+	return (psfapert / 2.0)
+end
+
+
+# AP_VRPRADIUS -- Verify the radial profile fitting radius.
+
+real procedure ap_vrpradius (ap)
+
+pointer	ap		# pointer to the apphot strucuture
+
+real	scale, radius
+int	scan(), nscan()
+real	apstatr()
+
+begin
+	scale = apstatr (ap, SCALE)
+
+	# Print the old value.
+	call printf ("Fitting radius in scale units (%g) (CR or value): ")
+	    call pargr (apstatr (ap, RPRADIUS))
+	call flush (STDOUT)
+
+	# Get the new value.
+	if (scan() == EOF)
+	    radius = apstatr (ap, RPRADIUS)
+	else {
+	    call gargr (radius)
+	    if (nscan () != 1)
+	        radius = apstatr (ap, RPRADIUS)
+	}
+
+	# Print the new  value.
+	call printf ("\tNew fitting radius: %g scale units  %g pixels\n")
+	    call pargr (radius)
+	    call pargr (scale 	* radius)
+	call apsetr (ap, RPRADIUS, radius)
+
+	return (radius)
+end
+
+
+# AP_VSTEP -- Verify the profile step size.
+
+real procedure ap_vstep (ap)
+
+pointer	ap		# pointer to the apphot strucuture
+
+real	scale, step
+int	scan(), nscan()
+real	apstatr()
+
+begin
+	scale = apstatr (ap, SCALE)
+
+	# Print the old value.
+	call printf ("Step size in scale units (%g) (CR or value): ")
+	    call pargr (apstatr (ap, RPSTEP))
+	call flush (STDOUT)
+
+	# Get the new value.
+	if (scan() == EOF)
+	    step = apstatr (ap, RPSTEP)
+	else {
+	    call gargr (step)
+	    if (nscan () != 1)
+	        step = apstatr (ap, RPSTEP)
+	}
+
+	# Print the new  value.
+	call printf ("\tNew step size: %g scale units  %g pixels\n")
+	    call pargr (step)
+	    call pargr (scale * step)
+	call apsetr (ap, RPSTEP, step)
+
+	return (step)
+end
diff --git a/noao/digiphot/apphot/aplib/apwcs.x b/noao/digiphot/apphot/aplib/apwcs.x
new file mode 100644
index 00000000..21ff7831
--- /dev/null
+++ b/noao/digiphot/apphot/aplib/apwcs.x
@@ -0,0 +1,117 @@
+# Copyright(c) 1986 Association of Universities for Research in Astronomy Inc.
+
+include <imio.h>
+include "../lib/apphot.h"
+
+# AP_ITOL -- Convert coordinates from the input coordinate system to the
+# logical coordinate system.
+
+procedure ap_itol (ap, xin, yin, xout, yout, npts)
+
+pointer	ap			# the apphot package descriptor
+real	xin[ARB]		# the input x coordinate
+real	yin[ARB]		# the input y coordinate
+real	xout[ARB]		# the output x coordinate 
+real	yout[ARB]		# the output y coordinate
+int	npts			# the number of coordinates to convert
+
+double	xt, yt
+pointer	ct
+int	i
+int	apstati()
+
+begin
+	ct = apstati (ap, CTIN)
+	if (ct == NULL) {
+	    call amovr (xin, xout, npts)
+	    call amovr (yin, yout, npts)
+	    return
+	}
+
+	do i = 1, npts {
+	    call mw_c2trand (ct, double (xin[i]), double (yin[i]), xt, yt) 
+	    xout[i] = xt
+	    yout[i] = yt
+	}
+end
+
+
+# AP_LTOO -- Convert coordinates from the logical coordinate system to the
+# output coordinate system.
+
+procedure ap_ltoo (ap, xin, yin, xout, yout, npts)
+
+pointer	ap			# the apphot package descriptor
+real	xin[ARB]		# the input x coordinate
+real	yin[ARB]		# the input y coordinate
+real	xout[ARB]		# the output x coordinate 
+real	yout[ARB]		# the output y coordinate
+int	npts			# the number of coordinates to convert
+
+double	xt, yt
+pointer	ct
+int	i
+int	apstati()
+
+begin
+	ct = apstati (ap, CTOUT)
+	if (ct == NULL) {
+	    call amovr (xin, xout, npts)
+	    call amovr (yin, yout, npts)
+	    return
+	}
+
+	do i = 1, npts {
+	    call mw_c2trand (ct, double (xin[i]), double (yin[i]), xt, yt) 
+	    xout[i] = xt
+	    yout[i] = yt
+	}
+end
+
+
+# AP_LTOV -- Convert coordinate from the logical coordinate system to the
+# output coordinate system.
+
+procedure ap_ltov (im, xin, yin, xout, yout, npts)
+
+pointer	im			# the input image descriptor
+real	xin[ARB]		# the input x coordinate
+real	yin[ARB]		# the input y coordinate
+real	xout[ARB]		# the output x coordinate 
+real	yout[ARB]		# the output y coordinate
+int	npts			# the number of coordinates to convert
+
+int	i, index1, index2
+
+begin
+	index1 = IM_VMAP(im,1)
+	index2 = IM_VMAP(im,2)
+	do i = 1, npts {
+	    xout[i] = xin[i] * IM_VSTEP(im,index1) + IM_VOFF(im,index1)
+	    yout[i] = yin[i] * IM_VSTEP(im,index2) + IM_VOFF(im,index2)
+	}
+end
+
+
+# AP_VTOL -- Convert coordinate from the tv coordinate system to the
+# logical coordinate system.
+
+procedure ap_vtol (im, xin, yin, xout, yout, npts)
+
+pointer	im			# the input image descriptor
+real	xin[ARB]		# the input x coordinate
+real	yin[ARB]		# the input y coordinate
+real	xout[ARB]		# the output x coordinate 
+real	yout[ARB]		# the output y coordinate
+int	npts			# the number of coordinates to convert
+
+int	i, index1, index2
+
+begin
+	index1 = IM_VMAP(im,1)
+	index2 = IM_VMAP(im,2)
+	do i = 1, npts {
+	    xout[i] = (xin[i] - IM_VOFF(im,index1)) / IM_VSTEP(im,index1)
+	    yout[i] = (yin[i] - IM_VOFF(im,index2)) / IM_VSTEP(im,index2)
+	}
+end
diff --git a/noao/digiphot/apphot/aplib/apwparam1.x b/noao/digiphot/apphot/aplib/apwparam1.x
new file mode 100644
index 00000000..54086aeb
--- /dev/null
+++ b/noao/digiphot/apphot/aplib/apwparam1.x
@@ -0,0 +1,415 @@
+include <time.h>
+include "../lib/apphotdef.h"
+include "../lib/apphot.h"
+include "../lib/noise.h"
+include	"../lib/center.h"
+include "../lib/fitsky.h"
+include "../lib/phot.h"
+
+# AP_PARAM -- Procedure to write the apphot parameters to a text file.
+
+procedure ap_param (ap, out, task)
+
+pointer	ap		# pointer to the apphot structure
+int	out		# output file descriptor
+char	task[ARB]	# task name
+
+int	nchars
+pointer	sp, outstr, date, time
+bool	itob()
+int	strmatch(), envfind(), gstrcpy(), apstati()
+real	apstatr()
+
+begin
+	if (out == NULL)
+	    return
+	 
+	# Allocate working space.
+	call smark (sp)
+	call salloc (outstr, SZ_LINE, TY_CHAR)
+	call salloc (date, SZ_DATE, TY_CHAR)
+	call salloc (time, SZ_DATE, TY_CHAR)
+
+	# Write the id.
+
+	nchars = envfind ("version", Memc[outstr], SZ_LINE)
+	if (nchars <= 0)
+	    nchars = gstrcpy ("NOAO/IRAF", Memc[outstr], SZ_LINE)
+	call ap_rmwhite (Memc[outstr], Memc[outstr], SZ_LINE)
+	call ap_sparam (out, "IRAF", Memc[outstr], "version",
+	    "current version of IRAF")
+
+	nchars = envfind ("userid", Memc[outstr], SZ_LINE)
+	call ap_sparam (out, "USER", Memc[outstr], "name", "user id")
+
+	call gethost (Memc[outstr], SZ_LINE)
+	call ap_sparam (out, "HOST", Memc[outstr], "computer",
+	    "IRAF host machine")
+
+	call apdate (Memc[date], Memc[time], SZ_DATE)
+	call ap_sparam (out, "DATE", Memc[date], "yyyy-mm-dd", "date")
+	call ap_sparam (out, "TIME", Memc[time], "hh:mm:ss", "time")
+
+	call ap_sparam (out, "PACKAGE", "apphot", "name",
+	    "name of IRAF package")
+	call ap_sparam (out, "TASK", task, "name", "name of apphot task")
+	call fprintf (out, "#\n")
+
+	# Write out the apphot parameters.
+	call ap_rparam (out, KY_SCALE, 1.0 / apstatr (ap, SCALE), UN_AUNITS,
+	    "scale in units per pixel")
+	call ap_rparam (out, KY_FWHMPSF, apstatr (ap, FWHMPSF), UN_ASCALEUNIT,
+	    "full width half maximum of the psf")
+	call ap_bparam (out, KY_POSITIVE, itob (apstati (ap, POSITIVE)),
+	    UN_ASWITCH, "positive feature")
+	call ap_rparam (out, KY_DATAMIN, apstatr (ap, DATAMIN), UN_ACOUNTS,
+	    "minimum good data value")
+	call ap_rparam (out, KY_DATAMAX, apstatr (ap, DATAMAX), UN_ACOUNTS,
+	    "maximum good data value")
+
+	# Write out the image header keyword parameters.
+	call apstats (ap, EXPOSURE, Memc[outstr], SZ_FNAME)
+	if (Memc[outstr] == EOS)
+	    call strcpy ("\"\"", Memc[outstr], SZ_FNAME)
+	call ap_sparam (out, KY_EXPOSURE, Memc[outstr], UN_AKEYWORD,
+	    "exposure time keyword")
+	call apstats (ap, AIRMASS, Memc[outstr], SZ_FNAME)
+	if (Memc[outstr] == EOS)
+	    call strcpy ("\"\"", Memc[outstr], SZ_FNAME)
+	call ap_sparam (out, KY_AIRMASS, Memc[outstr], UN_AKEYWORD,
+	    "airmass keyword")
+	call apstats (ap, FILTER, Memc[outstr], SZ_FNAME)
+	if (Memc[outstr] == EOS)
+	    call strcpy ("\"\"", Memc[outstr], SZ_FNAME)
+	call ap_sparam (out, KY_FILTER, Memc[outstr], UN_AKEYWORD,
+	    "filter keyword")
+	call apstats (ap, OBSTIME, Memc[outstr], SZ_FNAME)
+	if (Memc[outstr] == EOS)
+	    call strcpy ("\"\"", Memc[outstr], SZ_FNAME)
+	call ap_sparam (out, KY_OBSTIME, Memc[outstr], UN_AKEYWORD,
+	    "obstime keyword")
+	call fprintf (out, "#\n")
+
+	# Write the noise model parameters.
+	call ap_wnse (ap, out)
+
+	# Write the centering parameters.
+	call ap_wctrs (ap, out)
+
+	# Write sky fitting parameters.
+	call ap_wskys (ap, out)
+
+	# Write the phot parameters.
+	call ap_wwphot (ap, out)
+
+	# Write the polyphot parameters.
+	call ap_wpoly (ap, out)
+
+	# Write the radial profile parameters.
+	call ap_wprofs (ap, out)
+
+	# Write the psf fitting parameters.
+	call ap_wpsf (ap, out)
+
+	# Write the header banner
+	if (strmatch ("^center", task) > 0)
+	    call ap_cphdr (ap, out)
+	else if (strmatch ("^fitsky", task) > 0)
+	    call ap_sphdr (ap, out)
+	else if (strmatch ("^phot", task) > 0)
+	    call ap_maghdr (ap, out)
+	else if (strmatch ("^qphot", task) > 0)
+	    call ap_maghdr (ap, out)
+	else if (strmatch ("^wphot", task) > 0)
+	    call ap_maghdr (ap, out)
+	else if (strmatch ("^polyphot", task) > 0)
+	    call ap_yhdr (ap, out)
+	else if (strmatch ("^fitpsf", task) > 0)
+	    call ap_pfhdr (ap, out)
+	else if (strmatch ("^radprof", task) > 0)
+	    call ap_rphdr (ap, out)
+	#else if (strmatch ("^daofind", task) > 0)
+	    #call ap_fdhdr (ap, out)
+
+	call sfree (sp)
+end
+
+
+# AP_WCTRS -- Procedure to write out the centering parameters.
+
+procedure ap_wctrs (ap, out)
+
+pointer	ap		# apphot pointer
+int	out		# output file descriptor
+
+pointer	sp, str
+bool	itob()
+int	apstati()
+real	apstatr()
+
+begin
+	if (out == NULL)
+	    return
+
+	call smark (sp)
+	call salloc (str, SZ_FNAME, TY_CHAR)
+
+	if (AP_PCENTER(ap) != NULL) {
+	    call apstats (ap, CSTRING, Memc[str], SZ_FNAME)
+	    call ap_sparam (out, KY_CSTRING, Memc[str], UN_CALGORITHM,
+		"centering algorithm")
+	    call ap_rparam (out, KY_CAPERT, 2.0* apstatr (ap, CAPERT),
+	        UN_CSCALEUNIT, "centering box width")
+	    call ap_rparam (out, KY_CTHRESHOLD, apstatr (ap, CTHRESHOLD),
+	        UN_CSIGMA, "threshold for centering")
+	    call ap_rparam (out, KY_MINSNRATIO, apstatr (ap, MINSNRATIO),
+		UN_CNUMBER, "minimum signal to noise ratio")
+	    call ap_iparam (out, KY_CMAXITER, apstati (ap, CMAXITER),
+	        UN_CNUMBER, "maximum number of iterations")
+	    call ap_rparam (out, KY_MAXSHIFT, apstatr (ap, MAXSHIFT),
+	        UN_CSCALEUNIT, "maximum shift")
+	    call ap_bparam (out, KY_CLEAN, itob (apstati (ap, CLEAN)),
+		UN_CSWITCH, "apply clean algorithm before centering")
+	    call ap_rparam (out, KY_RCLEAN, apstatr (ap, RCLEAN),
+	        UN_CSCALEUNIT, "cleaning radius")
+	    call ap_rparam (out, KY_RCLIP, apstatr (ap, RCLIP), UN_CSCALEUNIT,
+		"clipping radius")
+	    call ap_rparam (out, KY_SIGMACLEAN, apstatr (ap, SIGMACLEAN),
+	        UN_CSIGMA, "k-sigma clean rejection criterion")
+	    call fprintf (out, "#\n")
+	}
+
+	call sfree (sp)
+end
+
+
+# AP_WSKYS -- Procedure to write out the sky fitting  parameters.
+
+procedure ap_wskys (ap, out)
+
+pointer	ap		# apphot structure
+int	out		# output pointer
+
+pointer sp, str
+bool	itob()
+int	apstati()
+real	apstatr()
+
+begin
+	if (out == NULL)
+	    return
+
+	call smark (sp)
+	call salloc (str, SZ_FNAME, TY_CHAR)
+
+	if (AP_PSKY(ap) != NULL) {
+	    call apstats (ap, SSTRING, Memc[str], SZ_FNAME)
+	    call ap_sparam (out, KY_SSTRING, Memc[str], UN_SALGORITHM,
+		" sky fitting algorithm")
+	    call ap_rparam (out, KY_ANNULUS, apstatr (ap, ANNULUS),
+	        UN_SSCALEUNIT, "inner radius of sky annulus")
+	    call ap_rparam (out, KY_DANNULUS, apstatr (ap, DANNULUS),
+	        UN_SSCALEUNIT, "width of the sky annulus")
+	    call ap_rparam (out, KY_SKY_BACKGROUND, apstatr (ap,
+	        SKY_BACKGROUND), UN_SCOUNTS, "user supplied sky value")
+	    call ap_rparam (out, KY_K1, apstatr (ap, K1), UN_SSIGMA,
+		"half width of sky histogram")
+	    call ap_rparam (out, KY_BINSIZE, apstatr (ap, BINSIZE),
+	        UN_SSIGMA, "width of sky histogram bin")
+	    call ap_bparam (out, KY_SMOOTH, itob (apstati (ap, SMOOTH)),
+		UN_SSWITCH, "Lucy smooth the histogram")
+	    call ap_iparam (out, KY_SMAXITER, apstati (ap, SMAXITER),
+	        UN_SNUMBER, "maximum number of iterations")
+	    call ap_rparam (out, KY_SLOCLIP, apstatr (ap, SLOCLIP),
+	        UN_SPERCENT, "lower clipping limit")
+	    call ap_rparam (out, KY_SHICLIP, apstatr (ap, SHICLIP),
+	        UN_SPERCENT, "upper clipping limit")
+	    call ap_iparam (out, KY_SNREJECT, apstati (ap, SNREJECT),
+	        UN_SNUMBER, "maximum number of rejection cycles")
+	    call ap_rparam (out, KY_SLOREJECT, apstatr (ap, SLOREJECT),
+	        UN_SSIGMA, "lower k-sigma rejection criterion")
+	    call ap_rparam (out, KY_SHIREJECT, apstatr (ap, SHIREJECT),
+	        UN_SSIGMA, "upper k-sigma rejection criterion")
+	    call ap_rparam (out, KY_RGROW, apstatr (ap, RGROW), UN_SSCALEUNIT,
+		"region growing radius")
+	    call fprintf (out, "#\n")
+	}
+
+	call sfree (sp)
+end
+
+
+# AP_WNSE -- Porcedure to compute the noise model parameters.
+
+procedure ap_wnse (ap, out)
+
+pointer	ap		# apphot pointer
+int	out		# output file descriptor
+
+pointer	sp, str
+real	apstatr()
+
+begin
+	if (out == NULL)
+	    return
+	call smark (sp)
+	call salloc (str, SZ_FNAME, TY_CHAR)
+
+	if (AP_NOISE(ap) != NULL) {
+	    call apstats (ap, NSTRING, Memc[str], SZ_FNAME)
+	    call ap_sparam (out, KY_NSTRING, Memc[str], UN_NMODEL,
+	        "noise model")
+	    call ap_rparam (out, KY_SKYSIGMA, apstatr (ap, SKYSIGMA),
+	        UN_NCOUNTS, "standard deviation of 1 sky pixel")
+	    call apstats (ap, GAIN, Memc[str], SZ_FNAME)
+	    if (Memc[str] == EOS)
+	        call strcpy ("\"\"", Memc[str], SZ_FNAME)
+	    call ap_sparam (out, KY_GAIN, Memc[str], UN_NKEYWORD,
+	        "gain keyword")
+	    call ap_rparam (out, KY_EPADU, apstatr (ap, EPADU), UN_NEPADU,
+	        "electrons per adu")
+	    call apstats (ap, CCDREAD, Memc[str], SZ_FNAME)
+	    if (Memc[str] == EOS)
+	        call strcpy ("\"\"", Memc[str], SZ_FNAME)
+	    call ap_sparam (out, KY_CCDREAD, Memc[str], UN_NKEYWORD,
+	        "read noise keyword")
+	    call ap_rparam (out, KY_READNOISE, apstatr (ap, READNOISE),
+	        UN_NELECTRONS, "electrons")
+	    call fprintf (out, "#\n")
+	}
+
+	call sfree (sp)
+end
+
+
+# AP_WWPHOT -- Procedure to write out the photometry parameters.
+
+procedure ap_wwphot (ap, out)
+
+pointer	ap		# apphot structure pointer
+int	out		# output file descriptor
+
+pointer	sp, str
+real	apstatr()
+
+begin
+	if (out == NULL)
+	    return
+
+	call smark (sp)
+	call salloc (str, SZ_LINE, TY_CHAR)
+
+	if (AP_PPHOT(ap) != NULL) {
+	    call apstats (ap, PWSTRING, Memc[str], SZ_LINE)
+	    call ap_sparam (out, KY_PWSTRING, Memc[str], UN_PMODEL,
+		"photometric weighting scheme")
+	    call apstats (ap, APERTS, Memc[str], SZ_LINE)
+	    call ap_sparam (out, KY_APERTS, Memc[str], UN_PSCALEUNIT,
+		"list of apertures")
+	    call ap_rparam (out, KY_ZMAG, apstatr (ap, ZMAG), UN_PZMAG,
+		"zero point of magnitdue scale")
+	    call fprintf (out, "#\n")
+	}
+
+	call sfree (sp)
+end
+
+
+# AP_RPARAM -- Procedure to encode a real apphot parameter.
+
+procedure ap_rparam (out, keyword, value, units, comments)
+
+int	out		# output file descriptor
+char	keyword[ARB]	# keyword string
+real	value		# parameter value
+char	units[ARB]	# units string
+char	comments[ARB]	# comment string
+
+begin
+	if (out == NULL)
+	    return
+
+	call strupr (keyword)
+        call fprintf (out,
+	    "#K%4t%-10.10s%14t = %17t%-23.7g%41t%-10.10s%52t%-10s\n")
+	    call pargstr (keyword)
+	    call pargr (value)
+	    call pargstr (units)
+	    call pargstr ("%-23.7g")
+	    call pargstr (comments)
+end
+
+
+# AP_IPARAM -- Procedure to encode an apphot integer parameter.
+
+procedure ap_iparam (out, keyword, value, units, comments)
+
+int	out		# output file descriptor
+char	keyword[ARB]	# keyword string
+int	value		# parameter value
+char	units[ARB]	# units string
+char	comments[ARB]	# comment string
+
+begin
+	if (out == NULL)
+	    return
+
+	call strupr (keyword)
+        call fprintf (out,
+	    "#K%4t%-10.10s%14t = %17t%-23d%41t%-10.10s%52t%-10s\n")
+	    call pargstr (keyword)
+	    call pargi (value)
+	    call pargstr (units)
+	    call pargstr ("%-23d")
+	    call pargstr (comments)
+end
+
+
+# AP_BPARAM -- Procedure to encode an apphot boolean parameter.
+
+procedure ap_bparam (out, keyword, value, units, comments)
+
+int	out		# output file descriptor
+char	keyword[ARB]	# keyword string
+bool	value		# parameter value
+char	units[ARB]	# units string
+char	comments[ARB]	# comment string
+
+begin
+	if (out == NULL)
+	    return
+
+	call strupr (keyword)
+        call fprintf (out,
+	    "#K%4t%-10.10s%14t = %17t%-23b%41t%-10.10s%52t%-10s\n")
+	    call pargstr (keyword)
+	    call pargb (value)
+	    call pargstr (units)
+	    call pargstr ("%-23b")
+	    call pargstr (comments)
+end
+
+
+# AP_SPARAM -- Procedure to encode an apphot string parameter.
+
+procedure ap_sparam (out, keyword, value, units, comments)
+
+int	out		# output file descriptor
+char	keyword[ARB]	# keyword string
+char	value[ARB]	# parameter value
+char	units[ARB]	# units string
+char	comments[ARB]	# comment string
+
+begin
+	if (out == NULL)
+	    return
+
+	call strupr (keyword)
+        call fprintf (out,
+	    "#K%4t%-10.10s%14t = %17t%-23.23s%41t%-10.10s%52t%-10s\n")
+	    call pargstr (keyword)
+	    call pargstr (value)
+	    call pargstr (units)
+	    call pargstr ("%-23s")
+	    call pargstr (comments)
+end
diff --git a/noao/digiphot/apphot/aplib/apwparam2.x b/noao/digiphot/apphot/aplib/apwparam2.x
new file mode 100644
index 00000000..1c15f26c
--- /dev/null
+++ b/noao/digiphot/apphot/aplib/apwparam2.x
@@ -0,0 +1,104 @@
+include "../lib/apphotdef.h"
+include "../lib/polyphot.h"
+include "../lib/fitpsf.h"
+include "../lib/radprof.h"
+
+
+# AP_WPROFS -- Procedure to print out the profile fitting parameters.
+
+procedure ap_wprofs (ap, out)
+
+pointer	ap		# apphot structure pointer
+int	out		# output file descriptor
+
+pointer sp, str
+int	apstati()
+real	apstatr()
+
+begin
+	if (out == NULL)
+	    return
+
+	call smark (sp)
+	call salloc (str, SZ_FNAME, TY_CHAR)
+
+	if (AP_RPROF(ap) != NULL) {
+	    call ap_rparam (out, KY_RPRADIUS, apstatr (ap, RPRADIUS),
+	        UN_RSCALEUNIT, "fitting radius")
+	    call ap_rparam (out, KY_RPSTEP, apstatr (ap, RPSTEP),
+	        UN_RSCALEUNIT, "step size in radius")
+	    call ap_iparam (out, KY_RPORDER, apstati (ap, RPORDER), UN_RNUMBER,
+		"number of splines pieces")
+	    call ap_rparam (out, KY_RPKSIGMA, apstatr (ap, RPKSIGMA),
+	        UN_RSIGMA, "k-sigma rejection criterion")
+	    call ap_iparam (out, KY_RPNREJECT, apstati (ap, RPNREJECT),
+	        UN_RNUMBER, "maximum number of rejection cycles")
+	    call fprintf (out, "#\n")
+	}
+
+	call sfree (sp)
+end
+
+
+# AP_WPOLY -- Procedure to write out the polyphot parameters.
+
+procedure ap_wpoly (ap, out)
+
+pointer	ap		# apphot structure pointer
+int	out		# output file descriptor
+
+pointer	sp, str
+real	apstatr()
+
+begin
+	if (out == NULL)
+	    return
+
+	call smark (sp)
+	call salloc (str, SZ_FNAME, TY_CHAR)
+
+	if (AP_POLY(ap) != NULL) {
+	    call ap_sparam (out, "WEIGHTING", "constant", "model", "")
+	    call ap_rparam (out, KY_PYZMAG, apstatr (ap, PYZMAG), UN_PYZMAG,
+		"zero point of magnitdue scale")
+	    call fprintf (out, "#\n")
+	}
+
+	call sfree (sp)
+end
+
+
+# AP_WPSF -- Procedure to write the psf fitting parameters .
+
+procedure ap_wpsf (ap, out)
+
+pointer	ap		# apphot strucuture pointer
+int	out		# output file descriptor
+
+pointer	sp, str
+int	apstati()
+real	apstatr()
+
+begin
+	if (out == NULL)
+	    return
+	call smark (sp)
+	call salloc (str, SZ_FNAME, TY_CHAR)
+
+	if (AP_PPSF(ap) != NULL) {
+	    call apstats (ap, PSFSTRING, Memc[str], SZ_FNAME)
+	    call ap_sparam (out, KY_PSFUNCTION, Memc[str], UN_PSFMODEL,
+		"fitting function")
+	    call ap_rparam (out, KY_PSFAPERT, 2.0 * apstatr (ap, PSFAPERT),
+	        UN_PSFSCALEUNIT, "width of the fitting box")
+	    call ap_iparam (out, KY_PMAXITER, apstati (ap, PMAXITER),
+	        UN_PSFSCALEUNIT, "maximum number of iterations")
+	    call ap_rparam (out, KY_PK2, apstatr (ap, PK2), UN_PSFSIGMA,
+		"k-sigma rejection limit for the fit")
+	    call ap_iparam (out, KY_PNREJECT, apstati (ap, PNREJECT),
+	        UN_PSFNUMBER, "maximum number of rejection cycles")
+	    call fprintf (out, "#\n")
+	}
+
+	call sfree (sp)
+end
diff --git a/noao/digiphot/apphot/aplib/apwres1.x b/noao/digiphot/apphot/aplib/apwres1.x
new file mode 100644
index 00000000..3d7b490a
--- /dev/null
+++ b/noao/digiphot/apphot/aplib/apwres1.x
@@ -0,0 +1,437 @@
+include "../lib/apphot.h"
+include "../lib/find.h"
+include "../lib/center.h"
+include "../lib/fitsky.h"
+
+# define the #N, #U, and #F daofind strings
+
+define	FD_NSTR	"#N%4tXCENTER%14tYCENTER%24tMAG%33tSHARPNESS%45t\
+SROUND%57tGROUND%69tID%80t\\\n"
+define	FD_USTR "#U%4tpixels%14tpixels%24t#%33t#%45t#%57t#%69t#%80t\\\n"
+define	FD_FSTR	"#F%4t%%-13.3f%14t%%-10.3f%24t%%-9.3f%33t%%-12.3f%45t\
+%%-12.3f%57t%%-12.3f%69t%%-6d%80t\\\n"
+define	FD_WSTR	"%4t%-10.3f%-10.3f%-9.3f%-12.3f%-12.3f%-12.3f%-6d\n"
+
+# AP_WFDPARAM -- Write the daofind parameters to the output file.
+
+procedure ap_wfdparam (out, ap)
+
+int	out	# the output file descriptor
+pointer	ap	# pointer to the apphot structure
+
+pointer	sp, str
+real	apstatr()
+
+begin
+	if (out == NULL)
+	    return
+
+	call smark (sp)
+	call salloc (str, SZ_FNAME, TY_CHAR)
+
+	# Write out the parameters.
+	call ap_param (ap, out, "daofind")
+	#call apstats (ap, IMNAME, Memc[str], SZ_FNAME)
+	call apstats (ap, IMROOT, Memc[str], SZ_FNAME)
+	call ap_sparam (out, KY_IMNAME, Memc[str], "imagename", "image name")
+	call ap_rparam (out, KY_FWHMPSF, apstatr (ap, FWHMPSF), UN_ASCALEUNIT,
+	    "fwhm of the psf")
+	call ap_rparam (out, KY_THRESHOLD, apstatr (ap, THRESHOLD),
+	    UN_FSIGMA, "detection threshold in sigma")
+	call ap_rparam (out, KY_NSIGMA, apstatr (ap, NSIGMA), UN_FSIGMA,
+	    "size of the kernel in fwhmpsf")
+	call ap_rparam (out, KY_RATIO, apstatr (ap, RATIO), UN_FNUMBER,
+	    "ratio of ysigma to xsigma")
+	call ap_rparam (out, KY_THETA, apstatr (ap, THETA), UN_FDEGREES,
+	    "position angle in degrees")
+	call fprintf (out, "#\n")
+	call ap_rparam (out, KY_SHARPLO, apstatr (ap, SHARPLO), UN_FNUMBER,
+	    "lower sharpness bound")
+	call ap_rparam (out, KY_SHARPHI, apstatr (ap, SHARPHI), UN_FNUMBER,
+	    "higher sharpness bound")
+	call ap_rparam (out, KY_ROUNDLO, apstatr (ap, ROUNDLO), UN_FNUMBER,
+	    "lower roundness bound")
+	call ap_rparam (out, KY_ROUNDHI, apstatr (ap, ROUNDHI), UN_FNUMBER,
+	    "higher roundness bound")
+	call fprintf (out, "#\n")
+
+	# Write out the header banner.
+	call ap_fdhdr (ap, out)
+
+	call sfree (sp)
+end
+
+
+# AP_FDHDR -- Write the daofind column banner to the output file.
+
+procedure ap_fdhdr (ap, out)
+
+pointer	ap	# pointer to the apphot structure (unused)
+int	out	# output file descriptor
+
+begin
+	if (out == NULL)
+	    return
+
+	call fprintf (out, FD_NSTR)
+	call fprintf (out, FD_USTR)
+	call fprintf (out, FD_FSTR)
+	call fprintf (out, "#\n")
+end
+
+
+# APSTDOUT -- Print the daofind results on the standard output.
+
+procedure apstdout (density, ptrs, ncols, nbox, cols, x, y, sharp, round1,
+        round2, nstars, ntotal, threshold)
+
+real	density[ncols,nbox]	# array of densities
+int	ptrs[ARB]		# array of line pointers 
+int	ncols, nbox		# dimensions of the data
+int	cols[ARB]		# array of column numbers
+real	x[ARB]			# x coordinates
+real	y[ARB]			# y coordinates
+real	sharp[ARB]		# sharpness
+real	round1[ARB]		# first roundness parameter
+real	round2[ARB]		# second roundness parameter
+int	nstars			# number of detected stars in the line
+int	ntotal			# total number of detected objects
+real	threshold		# threshold for detection
+
+int	i, middle
+real	den
+
+begin
+	middle = 1 + nbox / 2
+	do i = 1, nstars {
+	    call printf (" %7.2f  %7.2f  %7.3f  %6.3f  %6.3f  %6.3f  %4d\n")
+		call pargr (x[i])
+		call pargr (y[i])
+		if (threshold <= 0.0)
+		    den = INDEFR
+		else
+		    den = -2.5 * log10 (density[cols[i],ptrs[middle]] /
+		        threshold)
+		call pargr (den)
+		call pargr (sharp[i])
+		call pargr (round1[i])
+		call pargr (round2[i])
+		call pargi (ntotal + i)
+	}
+end
+
+
+# APDTFOUT -- Write the daofind results to the output file.
+
+procedure apdtfout (fd, density, ptrs, ncols, nbox, cols, x, y, sharp, round1,
+	round2, nstars, ntotal, threshold, stid)
+
+int	fd				# the output file descriptor
+real	density[ncols, nbox]		# densities
+int	ptrs[ARB]			# array of line pointers
+int	ncols, nbox			# dimensions of the data
+int	cols[ARB]			# column numbers
+real	x[ARB]				# xcoords
+real	y[ARB]				# y coords
+real	sharp[ARB]			# sharpnesses
+real	round1[ARB]			# first roundness
+real	round2[ARB]			# second roundness
+int	nstars				# number of detected stars in the line
+int	ntotal				# total number of detected objects
+real	threshold			# threshold for detection
+int	stid				# output file sequence number
+
+int	i, middle
+real	den
+
+begin
+	if (fd == NULL)
+	    return
+
+	middle = 1 + nbox / 2
+	do i = 1, nstars {
+	    call fprintf (fd, FD_WSTR)
+		call pargr (x[i])
+		call pargr (y[i])
+		if (threshold <= 0.0)
+		    den = INDEFR
+		else
+		    den = -2.5 * log10 (density[cols[i],ptrs[middle]] /
+		        threshold)
+		call pargr (den)
+		call pargr (sharp[i])
+		call pargr (round1[i])
+		call pargr (round2[i])
+		call pargi (stid + ntotal + i - 1)
+	}
+end
+
+
+# define the #N, #U and #K id strings
+
+define	ID_NSTR	"#N%4tIMAGE%24tXINIT%34tYINIT%44tID%50tCOORDS%73tLID%80t\\\n"
+define	ID_USTR	"#U%4timagename%24tpixels%34tpixels%44t##%50tfilename%73t\
+##%80t\\\n"
+define	ID_FSTR	"#F%4t%%-23s%24t%%-10.3f%34t%%-10.3f%44t%%-6d%50t%%-23s%73t\
+%%-6d%80t \n"
+define	ID_WSTR "%-23.23s%24t%-10.3f%34t%-10.3f%44t%-6d%50t%-23.23s%73t\
+%-6d%80t%c\n"
+
+# AP_IDHDR -- Print the id column header strings.
+
+procedure ap_idhdr (ap, fd)
+
+pointer	ap		# apphot descriptor (unused)
+int	fd		# output file descriptor
+
+begin
+	if (fd == NULL)
+	    return
+	call fprintf (fd, ID_NSTR)
+	call fprintf (fd, ID_USTR)
+	call fprintf (fd, ID_FSTR)
+	call fprintf (fd, "#\n")
+end
+
+
+# AP_WID -- Write the id record to a file.
+
+procedure ap_wid (ap, fd, xpos, ypos, id, lid, lastchar)
+
+pointer	ap		# pointer to apphot structure
+int	fd		# output file descriptor
+real	xpos		# x position
+real	ypos		# y position
+int	id		# id of the star
+int	lid		# list number
+int	lastchar	# last character in record
+
+pointer	sp, imname, clname 
+
+begin
+	if (fd == NULL)
+	    return
+
+	call smark (sp)
+	call salloc (imname, SZ_FNAME, TY_CHAR)
+	call salloc (clname, SZ_FNAME, TY_CHAR)
+
+	# Print description of object.
+	call apstats (ap, IMROOT, Memc[imname], SZ_FNAME)
+	call apstats (ap, CLROOT, Memc[clname], SZ_FNAME)
+	if (Memc[clname] == EOS)
+	    call strcpy ("nullfile", Memc[clname], SZ_FNAME)
+	call fprintf (fd, ID_WSTR)
+	    call pargstr (Memc[imname])
+	    call pargr (xpos)
+	    call pargr (ypos)
+	    call pargi (id)
+	    call pargstr (Memc[clname])
+	    call pargi (lid)
+	    call pargi (lastchar)
+
+	call sfree (sp)
+end
+
+
+# define the #N, #U and #K center strings
+
+define	CTR_NSTR  "#N%4tXCENTER%15tYCENTER%26tXSHIFT%34tYSHIFT%42tXERR%50t\
+YERR%66tCIER%71tCERROR%80t\\\n"
+define	CTR_USTR  "#U%4tpixels%15tpixels%26tpixels%34tpixels%42tpixels%50t\
+pixels%66t##%71tcerrors%80t\\\n"
+define	CTR_FSTR  "#F%4t%%-14.3f%15t%%-11.3f%26t%%-8.3f%34t%%-8.3f%42t\
+%%-8.3f%50t%%-15.3f%66t%%-5d%71t%%-9s%80t \n"
+define  CTR_WSTR   "%4t%-11.3f%-11.3f%-8.3f%-8.3f%-8.3f%-15.3f%-5d%-9.9s\
+%80t%c\n"
+
+
+# AP_CHDR -- Print the center algorithm column header strings.
+
+procedure ap_chdr (ap, fd)
+
+pointer	ap		# apphot descriptor (unused)
+int	fd		# output file descriptor
+
+begin
+	if (fd == NULL)
+	    return
+	call fprintf (fd, CTR_NSTR)
+	call fprintf (fd, CTR_USTR)
+	call fprintf (fd, CTR_FSTR)
+	call fprintf (fd, "#\n")
+end
+
+
+# AP_WCRES -- Write out the centering algorithm results to a file.
+
+procedure ap_wcres (ap, fd, ier, lastchar)
+
+pointer	ap		# pointer to apphot structure
+int	fd		# output file descriptor
+int	ier		# error code
+int	lastchar	# last character written out
+
+pointer	sp, str
+real	apstatr()
+
+begin
+	if (fd == NULL)
+	    return
+
+	call smark (sp)
+	call salloc (str, SZ_LINE, TY_CHAR)
+	call ap_cserrors (ier, Memc[str], SZ_LINE)
+
+	# Print the computed centers.
+	call fprintf (fd, CTR_WSTR)
+	    call pargr (apstatr (ap, OXCENTER))
+	    call pargr (apstatr (ap, OYCENTER))
+	    call pargr (apstatr (ap, OXSHIFT))
+	    call pargr (apstatr (ap, OYSHIFT))
+	    call pargr (apstatr (ap, XERR))
+	    call pargr (apstatr (ap, YERR))
+	    call pargi (ier)
+	    call pargstr (Memc[str])
+	    call pargi (lastchar)
+
+	call sfree (sp)
+end
+
+
+# AP_CSERRORS -- Encode the centering task error messages into a string.
+
+procedure ap_cserrors (ier, str, maxch)
+
+int	ier		# error code
+char	str[ARB]	# output str
+int	maxch		# maximum number of characters
+
+begin
+	switch (ier) {
+	case AP_CTR_NOAREA:
+	    call strcpy ("OffImage", str, maxch)
+        case AP_CTR_OUTOFBOUNDS:
+	    call strcpy ("EdgeImage", str, maxch)
+	case AP_CTR_NTOO_SMALL:
+	    call strcpy ("TooFewPts", str, maxch)
+	case AP_CTR_SINGULAR:
+	    call strcpy ("Singular", str, maxch)
+	case AP_CTR_NOCONVERGE:
+	    call strcpy ("BadFit", str, maxch)
+	case AP_CTR_BADSHIFT:
+	    call strcpy ("BigShift", str, maxch)
+	case AP_CTR_LOWSNRATIO:
+	    call strcpy ("LowSnr", str, maxch)
+	case AP_CTR_BADDATA:
+	    call strcpy ("BadPixels", str, maxch)
+	default:
+	    call strcpy ("NoError", str, maxch)
+	}
+end
+
+
+# define the #N, #U and #K fitsky strings
+
+define	SKY_NSTR  "#N%4tMSKY%19tSTDEV%34tSSKEW%49tNSKY%56tNSREJ%66tSIER\
+%71tSERROR%80t\\\n"
+define	SKY_USTR  "#U%4tcounts%19tcounts%34tcounts%49tnpix%56tnpix%66t##\
+%71tserrors%80t\\\n"
+define	SKY_FSTR  "#F%4t%%-18.7g%19t%%-15.7g%34t%%-15.7g%49t%%-7d%56t\
+%%-9d%66t%%-5d%71t%%-9s%80t \n"
+define  SKY_WSTR  "%4t%-15.7g%-15.7g%-15.7g%-7d%-9d%-5d%-9.9s%80t%c\n"
+
+# AP_SHDR -- Print the sky fitting column header strings.
+
+procedure ap_shdr (ap, fd)
+
+pointer	ap		# apphot descriptor (unused)
+int	fd		# output file descriptor
+
+begin
+	if (fd == NULL)
+	    return
+
+	call fprintf (fd, SKY_NSTR)
+	call fprintf (fd, SKY_USTR)
+	call fprintf (fd, SKY_FSTR)
+	call fprintf (fd, "#\n")
+end
+
+
+# AP_WSRES -- Write the results of the sky fitting algorithms to the output
+# file.
+
+procedure ap_wsres (ap, fd, ier, lastchar)
+
+pointer	ap		# pointer to apphot structure
+int	fd		# output file descriptor
+int	ier		# error code
+int	lastchar	# last character
+
+int	apstati()
+real	apstatr()
+
+pointer	sp, str
+
+begin
+	if (fd == NULL)
+	    return
+
+	call smark (sp)
+	call salloc (str, SZ_LINE, TY_CHAR)
+	call ap_sserrors (ier, Memc[str], SZ_LINE)
+
+	# Print the computed sky value and statistics.
+	call fprintf (fd, SKY_WSTR)
+	    call pargr (apstatr (ap, SKY_MODE))
+	    call pargr (apstatr (ap, SKY_SIGMA))
+	    call pargr (apstatr (ap, SKY_SKEW))
+	    call pargi (apstati (ap, NSKY))
+	    call pargi (apstati (ap, NSKY_REJECT))
+	    call pargi (ier)
+	    call pargstr (Memc[str])
+	    call pargi (lastchar)
+
+	call sfree (sp)
+end
+
+
+# AP_SSERRORS -- Encode the sky fitting error messages in a string.
+
+procedure ap_sserrors (ier, str, maxch)
+
+int	ier		# integer error code
+char	str[ARB]	# the output string
+int	maxch		# maximum number of characters
+
+begin
+	switch (ier) {
+	case AP_NOSKYAREA:
+	    call strcpy ("OffImage", str, maxch)
+	case AP_SKY_OUTOFBOUNDS:
+	    call strcpy ("EdgeImage", str, maxch)
+	case AP_NOHISTOGRAM:
+	    call strcpy ("NoHist", str, maxch)
+	case AP_FLAT_HIST:
+	    call strcpy ("FlatHist", str, maxch)
+	case AP_NSKY_TOO_SMALL:
+	    call strcpy ("TooFewPts", str, maxch)
+	case AP_SKY_SINGULAR:
+	    call strcpy ("Singular", str, maxch)
+	case AP_SKY_NOCONVERGE:
+	    call strcpy ("BadFit", str, maxch)
+	case AP_NOGRAPHICS:
+	    call strcpy ("NoGraph", str, maxch)
+	case AP_NOSKYFILE:
+	    call strcpy ("NoFile", str, maxch)
+	case AP_EOFSKYFILE:
+	    call strcpy ("ShortFile", str, maxch)
+	case AP_BADSKYSCAN:
+	    call strcpy ("BadRecord", str, maxch)
+	case AP_BADPARAMS:
+	    call strcpy ("BadParams", str, maxch)
+	default:
+	    call strcpy ("NoError", str, maxch)
+	}
+end
diff --git a/noao/digiphot/apphot/aplib/apwres2.x b/noao/digiphot/apphot/aplib/apwres2.x
new file mode 100644
index 00000000..1c5d38a5
--- /dev/null
+++ b/noao/digiphot/apphot/aplib/apwres2.x
@@ -0,0 +1,347 @@
+include "../lib/apphotdef.h"
+include "../lib/photdef.h"
+
+include "../lib/apphot.h"
+include "../lib/fitsky.h"
+include "../lib/phot.h"
+include "../lib/polyphot.h"
+
+# define the #N, #U and #K phot/wphot strings
+
+define	MAG1_NSTR  "#N%4tITIME%19tXAIRMASS%34tIFILTER%57tOTIME%80t\\\n"
+define	MAG1_USTR  "#U%4ttimeunit%19tnumber%34tname%57ttimeunit%80t\\\n"
+define	MAG1_FSTR  "#F%4t%%-18.7g%19t%%-15.7g%34t%%-23s%57t%%-23s%80t \n"
+define	MAG1_WSTR  "%4t%-15.7g%-15.7g%-23.23s%-23.23s%80t\\\n"
+
+define  MAG2_NSTR  "#N%4tRAPERT%13tSUM%27tAREA%38tFLUX%52tMAG%59tMERR%66t\
+PIER%71tPERROR%80t\\\n"
+define  MAG2_USTR  "#U%4tscale%13tcounts%27tpixels%38tcounts%52tmag%59t\
+mag%66t##%71tperrors%80t\\\n"
+define  MAG2_FSTR  "#F%4t%%-12.2f%13t%%-14.7g%27t%%-11.7g%38t%%-14.7g%52t\
+%%-7.3f%59t%%-6.3f%66t%%-5d%71t%%-9s%80t \n"
+define  MAG2_WSTR  "%4t%-9.2f%-14.7g%-11.7g%-14.7g%-7.3f%-6.3f%-5d%-9.9s\
+%79t%2s\n"
+
+
+# AP_MHDR -- Print the phot/wphot/qphot column header strings.
+
+procedure ap_mhdr (ap, fd)
+
+pointer	ap		# apphot descriptor (unused)
+int	fd		# output file descriptor
+
+begin
+	if (fd == NULL)
+	    return
+
+	call fprintf (fd, MAG1_NSTR)
+	call fprintf (fd, MAG1_USTR)
+	call fprintf (fd, MAG1_FSTR)
+	call fprintf (fd, "#\n")
+
+	call fprintf (fd, MAG2_NSTR)
+	call fprintf (fd, MAG2_USTR)
+	call fprintf (fd, MAG2_FSTR)
+	call fprintf (fd, "#\n")
+end
+
+
+# AP_WMRES -- Write the results of the phot/qphot/wphot tasks to the output 
+# file.
+
+procedure ap_wmres (ap, fd, i, pier, endstr)
+
+pointer	ap		# pointer to apphot structure
+int 	fd		# output text file
+int	i		# index of variable length field
+int	pier		# photometric error
+char	endstr[ARB]	# termination string
+
+int	ier
+pointer	sp, str, phot
+real	sky_val
+real	apstatr()
+
+begin
+	# Initialize.
+	if (fd == NULL)
+	    return
+
+	phot = AP_PPHOT(ap)
+	call smark (sp)
+	call salloc (str, SZ_LINE, TY_CHAR)
+
+	# Write out the exposure time, airmass and filter information.
+	if (i <= 1) {
+	    call fprintf (fd, MAG1_WSTR)
+	        call pargr (apstatr (ap, ITIME))
+	        call pargr (apstatr (ap, XAIRMASS))
+	    call apstats (ap, FILTERID, Memc[str], SZ_FNAME)
+	        call pargstr (Memc[str])
+	    call apstats (ap, OTIME, Memc[str], SZ_FNAME)
+	        call pargstr (Memc[str])
+	}
+
+	# Write out the error code.
+	if (IS_INDEFR(Memr[AP_MAGS(phot)+i-1])) {
+	    if (pier != AP_APERT_OUTOFBOUNDS)
+		ier = pier
+	    else if (i > AP_NMAXAP(phot))
+	        ier = AP_APERT_OUTOFBOUNDS
+	    else
+	        ier = AP_OK
+	} else if (i >= AP_NMINAP(phot)) {
+	    ier = AP_APERT_BADDATA
+	} else {
+	    ier = AP_OK
+	}
+	call ap_pserrors (ier, Memc[str], SZ_LINE)
+
+	# Write out the photometry results.
+	call fprintf (fd, MAG2_WSTR)
+	if (i == 0) {
+	    call pargr (0.0)
+	    call pargr (0.0)
+	    call pargr (0.0)
+	    call pargr (INDEFR)
+	    call pargr (INDEFR)
+	    call pargi (ier)
+	    call pargstr (Memc[str])
+	    call pargstr (endstr)
+	} else {
+	    call pargr (Memr[AP_APERTS(phot)+i-1])
+	    call pargd (Memd[AP_SUMS(phot)+i-1])
+	    call pargd (Memd[AP_AREA(phot)+i-1])
+	    sky_val = apstatr (ap, SKY_MODE)
+	    if (IS_INDEFR(sky_val))
+		call pargr (0.0)
+	    else
+		call pargr (real (Memd[AP_SUMS(phot)+i-1] - sky_val *
+		    Memd[AP_AREA(phot)+i-1]))
+	    call pargr (Memr[AP_MAGS(phot)+i-1])
+	    if (Memr[AP_MAGERRS(phot)+i-1] > 99.999)
+		call pargr (INDEFR)
+	    else
+	        call pargr (Memr[AP_MAGERRS(phot)+i-1])
+	    call pargi (ier)
+	    call pargstr (Memc[str])
+	    call pargstr (endstr)
+	}
+
+	call sfree (sp)
+end
+
+
+# AP_PSERRORS -- Encode the photometric errors string.
+
+procedure ap_pserrors (ier, str, maxch)
+
+int	ier		# photometry error code
+char	str[ARB]	# output string
+int	maxch		# maximum length of string
+
+begin
+	switch (ier) {
+	case AP_APERT_NOAPERT:
+	    call strcpy ("OffImage", str, maxch)
+	case AP_APERT_OUTOFBOUNDS:
+	    call strcpy ("EdgeImage", str, maxch)
+	case AP_APERT_NOSKYMODE:
+	    call strcpy ("NoSky", str, maxch)
+	case AP_APERT_NEGMAG:
+	    call strcpy ("NoFlux", str, maxch)
+	case AP_APERT_BADDATA:
+	    call strcpy ("BadPixels", str, maxch)
+	default:
+	    call strcpy ("NoError", str, maxch)
+	}
+end
+
+
+# define the #N, #U and #K polyphot strings
+
+define	PY_NSTR1  "#N%4tITIME%19tXAIRMASS%34tIFILTER%57tOTIME%80t\\\n"
+define	PY_USTR1  "#U%4ttimeunit%19tnumber%34tname%57ttimeunit%80t\\\n"
+define	PY_FSTR1  "#F%4t%%-18.7g%19t%%-15.7g%34t%%-23s%57t%%-23s%80t \n"
+define	PY_WSTR1  "%4t%-15.7g%-15.7g%-23.23s%-23.23s%80t\\\n"
+
+define  PY_NSTR2  "#N%4tSUM%19tAREA%34tFLUX%49tMAG%58tMERR%66tPIER%71t\
+PERROR%80t\\\n"
+define  PY_USTR2  "#U%4tcounts%19tpixels%34tcounts%49tmag%58tmag%66t##%71t\
+perrors%80t\\\n"
+define	PY_FSTR2  "#F%4t%%-18.7g%19t%%-15.7g%34t%%-15.7g%49t%%-9.3f%58t\
+%%-7.3f%66t%%-5d%71t%%-9s%80t \n"
+define  PY_WSTR2  "%4t%-15.7g%-15.7g%-15.7g%-9.3f%-7.3f%-5d%-9.9s%80t\\\n"
+
+define	PY_NSTR3  "#N%4tPOLYGONS%24tPID%29tOLDXMEAN%38tOLDYMEAN%47t\
+XMEAN%56tYMEAN%65tMINRAD%74tNVER%80t\\\n"
+define	PY_USTR3  "#U%4tfilename%24t##%29tpixels%38tpixels%47t\
+pixels%56tpixels%65tpixels%74t##%80t\\\n"
+define	PY_FSTR3  "#F%4t%%-23s%24t%%-5d%29t%%-9.2f%38t%%-9.2f%47t\
+%%-9.2f%56t%%-9.2f%65t%%-9.2f%74t%%-5d%80t \n"
+define  PY_WSTR3  "%4t%-20.20s%-5d%-9.2f%-9.2f%-9.2f%-9.2f%-9.2f%-5d%80t\\\n"
+
+define  PY_NSTR4  "#N%4tXVERTEX%13tYVERTEX%80t\\\n"
+define  PY_USTR4  "#U%4tpixels%13tpixels%80t\\\n"
+define	PY_FSTR4  "#F%4t%%-12.2f%13t%%-9.2f%80t \n"
+define  PY_WSTR4  "%4t%-9.2f%-9.2f%79t%2s\n"
+
+
+# AP_PLHDR -- Print the polyphot column header strings.
+
+procedure ap_plhdr (ap, fd)
+
+pointer	ap		# apphot descriptor (unused)
+int	fd		# output file descriptor
+
+begin
+	if (fd == NULL)
+	    return
+
+	call fprintf (fd, PY_NSTR1)
+	call fprintf (fd, PY_USTR1)
+	call fprintf (fd, PY_FSTR1)
+	call fprintf (fd, "#\n")
+
+	call fprintf (fd, PY_NSTR2)
+	call fprintf (fd, PY_USTR2)
+	call fprintf (fd, PY_FSTR2)
+	call fprintf (fd, "#\n")
+
+	call fprintf (fd, PY_NSTR3)
+	call fprintf (fd, PY_USTR3)
+	call fprintf (fd, PY_FSTR3)
+	call fprintf (fd, "#\n")
+
+	call fprintf (fd, PY_NSTR4)
+	call fprintf (fd, PY_USTR4)
+	call fprintf (fd, PY_FSTR4)
+	call fprintf (fd, "#\n")
+end
+
+
+# AP_WLRES -- Write the results of the polyphot task to the output file.
+
+procedure ap_wlres (py, fd, xver, yver, nver, pid, pier)
+
+pointer	py		# pointer to apphot structure
+int	fd		# output file descriptor
+real	xver[ARB]	# coords of x vertices
+real	yver[ARB]	# coords of y vertices
+int	nver		# number of vertices
+int	pid		# polygon number
+int	pier		# photometric error
+
+int	i
+pointer	sp, str, pyname
+real	sky_val
+int	apstati()
+double	apstatd()
+real	apstatr()
+
+begin
+	if (fd == NULL)
+	    return
+
+	# Allocate space.
+	call smark (sp)
+	call salloc (pyname, SZ_FNAME, TY_CHAR)
+	call salloc (str, SZ_LINE, TY_CHAR)
+
+	# Write out the exposure time, airmass and filter id.
+	call fprintf (fd, PY_WSTR1)
+	    call pargr (apstatr (py, ITIME))
+	    call pargr (apstatr (py, XAIRMASS))
+	call apstats (py, FILTERID, Memc[str], SZ_FNAME)
+	    call pargstr (Memc[str])
+	call apstats (py, OTIME, Memc[str], SZ_FNAME)
+	    call pargstr (Memc[str])
+
+	# Write the photometry results.
+	call ap_spyerrors (pier, Memc[str], SZ_LINE)
+	sky_val = apstatr (py, SKY_MODE)
+	call fprintf (fd, PY_WSTR2)
+	    call pargd (apstatd (py, PYFLUX))
+	    call pargd (apstatd (py, PYNPIX))
+	    if (IS_INDEFR(sky_val))
+		call pargr (0.0)
+	    else
+		call pargr (real (apstatd (py, PYFLUX) - sky_val *
+		    apstatd (py, PYNPIX)))
+	    call pargr (apstatr (py, PYMAG))
+	    if (apstatr (py, PYMAGERR) > 99.999)
+		call pargr (INDEFR)
+	    else
+	        call pargr (apstatr (py, PYMAGERR))
+	    call pargi (pier)
+	    call pargstr (Memc[str])
+
+	# Write the polygon characteristics
+	#call apstats (py, PYNAME, Memc[pyname], SZ_FNAME)
+	call apstats (py, PYROOT, Memc[pyname], SZ_FNAME)
+	call fprintf (fd, PY_WSTR3)
+	    if (Memc[pyname] == EOS)
+		call pargstr ("nullfile")
+	    else
+	        call pargstr (Memc[pyname])
+	    call pargi (pid)
+	    call pargr (apstatr (py, OPYXMEAN))
+	    call pargr (apstatr (py, OPYYMEAN))
+	    call pargr (apstatr (py, OPYCX))
+	    call pargr (apstatr (py, OPYCY))
+	    call pargr (apstatr (py, PYMINRAD))
+	    call pargi (apstati (py, PYNVER))
+
+	# Write out the vertices of the polygon.
+	if (nver == 0) {
+	    call fprintf (fd, PY_WSTR4)
+		call pargr (INDEFR)
+		call pargr (INDEFR)
+		call pargstr ("  ")
+	} else {
+	    do i = 1, nver {
+	        call fprintf (fd, PY_WSTR4)
+	        if (nver == 1) {
+		    call pargr (xver[i])
+		    call pargr (yver[i])
+		    call pargstr ("  ")
+	        } else if (i == nver) {
+		    call pargr (xver[i])
+		    call pargr (yver[i])
+		    call pargstr ("* ")
+	        } else {
+		    call pargr (xver[i])
+		    call pargr (yver[i])
+		    call pargstr ( "*\\")
+	        }
+	    }
+	}
+
+	call sfree (sp)
+end
+
+
+# AP_SPYERRORS -- Encode the polygon fitting error in a string.
+
+procedure ap_spyerrors (ier, str, maxch)
+
+int	ier		# error code
+char	str[ARB]	# output string
+int	maxch		# maximum number of characters
+
+begin
+	switch (ier) {
+	case PY_NOPOLYGON:
+	    call strcpy ("NoPolygon", str, maxch)
+	case PY_OUTOFBOUNDS:
+	    call strcpy ("EdgeImage", str, maxch)
+	case PY_NOPIX:
+	    call strcpy ("NoPixels", str, maxch)
+	case PY_NOSKYMODE:
+	    call strcpy ("NoSky", str, maxch)
+	case PY_BADDATA:
+	    call strcpy ("BadPixels", str, maxch)
+	default:
+	    call strcpy ("NoError", str, maxch)
+	}
+end
diff --git a/noao/digiphot/apphot/aplib/apwres3.x b/noao/digiphot/apphot/aplib/apwres3.x
new file mode 100644
index 00000000..757361dc
--- /dev/null
+++ b/noao/digiphot/apphot/aplib/apwres3.x
@@ -0,0 +1,132 @@
+include "../lib/apphotdef.h"
+include "../lib/radprofdef.h"
+include "../lib/apphot.h"
+include "../lib/radprof.h"
+
+# define the #N, #U and #K radprof strings
+
+define  RP_NSTR1  "#N%4tPFWHM%14tINORM%29tTINORM%66tRIER%71tRERROR%80t\\\n"
+define  RP_USTR1  "#U%4tScale%14tcounts%29tcounts%66t##%71trerrors%80t\\\n"
+define  RP_FSTR1  "#F%4t%%-13.3f%14t%%-15.7f%29t%%-36.7f%66t%%-5d%71t\
+%%-9s%80t \n"
+define  RP_WSTR1  "%4t%-10.3f%-15.7g%-36.7g%-5d%-9.9s%80t\\\n"
+
+define  RP_NSTR2  "#N%4tPRADIUS%14tINTENSITY%29tTINTENSITY%80t\\\n"
+define  RP_USTR2  "#U%4tscale%14tcounts%29tcounts%80t\\\n"
+define  RP_FSTR2  "#F%4t%%-13.3f%14t%%-15.7f%29t%%-15.7f%80t \n"
+define  RP_WSTR2  "%4t%-10.3f%-15.7g%-15.7g%79t%2s\n"
+
+
+# AP_RHDR -- Print the radprof column header strings.
+
+procedure ap_rhdr (ap, fd)
+
+pointer	ap		# apphot descriptor (unused)
+int	fd		# output file descriptor
+
+begin
+	if (fd == NULL)
+	    return
+	call fprintf (fd, RP_NSTR1)
+	call fprintf (fd, RP_USTR1)
+	call fprintf (fd, RP_FSTR1)
+	call fprintf (fd, "#\n")
+	call fprintf (fd, RP_NSTR2)
+	call fprintf (fd, RP_USTR2)
+	call fprintf (fd, RP_FSTR2)
+	call fprintf (fd, "#\n")
+end
+
+
+# AP_WRRES -- Write the results of the radprof task to the output file.
+
+procedure ap_wrres (ap, fd, ier)
+
+pointer	ap	# pointer to apphot structure
+int	fd	# output text file descriptor
+int	ier	# radial profile error
+
+int	i, nrpts
+pointer	sp, str, rprof
+real	apstatr()
+
+begin
+	# Initialize.
+	if (fd == NULL)
+	    return
+	rprof = AP_RPROF(ap)
+	call smark (sp)
+	call salloc (str, SZ_LINE, TY_CHAR)
+
+	# Print the radprof parameters.
+	call ap_srerrors (ier, Memc[str], SZ_LINE)
+	call fprintf (fd, RP_WSTR1)
+	    call pargr (apstatr (ap, RPFWHM) / apstatr (ap, SCALE))
+	    call pargr (apstatr (ap, INORM))
+	    call pargr (apstatr (ap, TNORM))
+	    call pargi (ier)
+	    call pargstr (Memc[str])
+
+	# Print the radial profile.
+	nrpts = apstatr (ap, RPRADIUS) / apstatr (ap, RPSTEP) + 1
+	if (nrpts == 0) {
+	    call fprintf (fd, RP_WSTR2)
+	        call pargr (INDEFR)
+	        call pargr (INDEFR)
+	        call pargr (INDEFR)
+	        call pargstr ("  ")
+	} else {
+	    do i = 1, nrpts {
+		if (nrpts == 1) {
+	            call fprintf (fd, RP_WSTR2)
+		        call pargr (Memr[AP_RPDIST(rprof)+i-1] / AP_SCALE(ap))
+		        call pargr (Memr[AP_INTENSITY(rprof)+i-1])
+		        call pargr (Memr[AP_TINTENSITY(rprof)+i-1])
+		        call pargstr ("  ")
+	        } if (i == nrpts) {
+	            call fprintf (fd, RP_WSTR2)
+		        call pargr (Memr[AP_RPDIST(rprof)+i-1] / AP_SCALE(ap))
+		        call pargr (Memr[AP_INTENSITY(rprof)+i-1])
+		        call pargr (Memr[AP_TINTENSITY(rprof)+i-1])
+		        call pargstr ("* ")
+	        } else {
+	            call fprintf (fd, RP_WSTR2)
+		        call pargr (Memr[AP_RPDIST(rprof)+i-1] / AP_SCALE(ap))
+		        call pargr (Memr[AP_INTENSITY(rprof)+i-1])
+		        call pargr (Memr[AP_TINTENSITY(rprof)+i-1])
+		        call pargstr ("*\\")
+	        }
+	    }
+	}
+
+	call sfree (sp)
+end
+
+
+# AP_SRERRORS -- Encode the radial profile error message in a string.
+
+procedure ap_srerrors (ier, str, maxch)
+
+int	ier		# error code
+char	str[ARB]	# encoded error string
+int	maxch		# maximum number of characters
+
+begin
+    	switch (ier) {
+	case AP_RP_NOPROFILE:
+	    call sprintf (str, maxch, "%s")
+	        call pargstr ("OffImage")
+	case AP_RP_OUTOFBOUNDS:
+	    call sprintf (str, maxch, "%s")
+	        call pargstr ("EdgeImage")
+	case AP_RP_NPTS_TOO_SMALL:
+	    call sprintf (str, maxch, "%s")
+	        call pargstr ("TooFewPts")
+	case AP_RP_SINGULAR:
+	    call sprintf (str, maxch, "%s")
+	        call pargstr ("Singular")
+	default:
+	    call sprintf (str, maxch, "%s")
+	        call pargstr ("NoError")
+	}
+end
diff --git a/noao/digiphot/apphot/aplib/apwres4.x b/noao/digiphot/apphot/aplib/apwres4.x
new file mode 100644
index 00000000..67276ea1
--- /dev/null
+++ b/noao/digiphot/apphot/aplib/apwres4.x
@@ -0,0 +1,238 @@
+include "../lib/apphotdef.h"
+include "../lib/fitpsfdef.h"
+include "../lib/apphot.h"
+include "../lib/fitpsf.h"
+
+# define the #N, #U and #K fitpsf strings
+
+define  PSF_RNSTR1  "#N%4tXCENTER%14tYCENTER%24tRSIGMA%33tAMPLITUDE%48t\
+SKY%80t\\\n"
+define  PSF_RUSTR1  "#U%4tpixels%14tpixels%24tpixels%33tcounts%48t\
+counts%80t\\\n"
+define  PSF_RFSTR1  "#F%4t%%-13.3f%14t%%-10.3f%24t%%-9.2f%33t%%-15.7g%48t\
+%%-15.7g%80t \n"
+define  PSF_RWSTR1   "%4t%-10.3f%14t%-10.3f%24t%-9.2f%33t%-15.7g%48t\
+%-15.7g%80t\\\n"
+
+define  PSF_RNSTR2  "#N%4tEXCENTER%14tEYCENTER%24tERSIGMA%33tEAMPLITUDE%48t\
+ESKY%63tIER%68tERROR%80t\\\n"
+define  PSF_RUSTR2  "#U%4tpixels%14tpixels%24tpixels%33tcounts%48t\
+counts%63t##%68terrors%80t\\\n"
+define  PSF_RFSTR2  "#F%4t%%-13.3f%14t%%-10.3f%24t%%-9.3f%33t%%-15.7g%48t\
+%%-15.7g%63t%%-5d%68t%%-13s%80t \n"
+define  PSF_RWSTR2  "%4t%-10.3f%14t%-10.3f%24t%-9.3f%33t%-15.7g%48t\
+%-15.7g%63t%-5d%68t%-13.13s\n"
+
+define  PSF_ENSTR1  "#N%4tXCENTER%14tYCENTER%24tXSIGMA%33tYSIGMA%42t\
+ROT%49tAMPLITUDE%64tSKY%80t\\\n"
+define  PSF_EUSTR1  "#U%4tpixels%14tpixels%24tpixels%33tpixels%42t\
+deg%49tcounts%64tcounts%80t\\\n"
+define  PSF_EFSTR1  "#F%4t%%-13.3f%14t%%-10.3f%24t%%-9.2f%33t%%-9.2f%42t\
+%%-7.2f%49t%%-15.7g%64t%%-15.7g%80t \n"
+define  PSF_EWSTR1  "%4t%-10.3f%-10.3f%-9.2f%-9.2f%-7.2f%-15.7g%-15.7g%80t\\\n"
+
+define  PSF_ENSTR2  "#N%4tEXCENTER%14tEYCENTER%24tEXSIGMA%33tEYSIGMA%42t\
+EROT%49tEAMPLITDE%64tESKY%80t\\\n"
+define  PSF_EUSTR2  "#U%4tpixels%14tpixels%24tpixels%33tpixels%42t\
+deg%49tcounts%64tcounts%80t\\\n"
+define  PSF_EFSTR2  "#F%4t%%-13.3f%14t%%-10.3f%24t%%-9.3f%33t%%-9.3f%42t\
+%%-7.2f%49t%%-15.7g%64t%%-15.7g%80t \n"
+define  PSF_EWSTR2  "%4t%-10.3f%-10.3f%-9.3f%-9.3f%-7.2f%-15.7g%-15.7g%80t\\\n"
+
+define  PSF_ENSTR3  "#N%4tIER%9tERROR%80t\\\n"
+define  PSF_EUSTR3  "#U%4t##%9terrors%80t\\\n"
+define  PSF_EFSTR3  "#F%4t%%-8d%9t%%-13s%80t \n"
+define  PSF_EWSTR3  "%4t%-5d%-13.13s%80t \n"
+
+
+define  PSF_MNSTR1   "#N%4tXCENTER%14tYCENTER%24tRGYRAT%33tELLIP%42t\
+ROT%49tAMPLITUDE%64tSKY%80t\\\n"
+define  PSF_MUSTR1  "#U%4tpixels%14tpixels%24tpixels%33tratio%42tdeg%49t\
+counts%64tcounts%80t\\\n"
+define  PSF_MFSTR1  "#F%4t%%-13.3f%14t%%-10.3f%24t%%-9.2f%33t%%-9.2f%42t\
+%%-7.2f%49t%%-15.7g%64t%%-15.7f%80t \n"
+define  PSF_MWSTR1  "%4t%-10.3f%-10.3f%-9.2f%-9.2f%-7.2f%-15.7g%-15.7g%80t\\\n"
+
+define  PSF_MNSTR2  "#N%4tEXCENTER%14tEYCENTER%24tERGYRAT%33tEELLIP%42t\
+EROT%49tEAMPLITUDE%64tESKY%80t\\\n"
+define  PSF_MUSTR2  "#U%4tpixels%14tpixels%24tpixels%33tratio%42tdeg%49t\
+counts%64tcounts%80t\\\n"
+define  PSF_MFSTR2  "#F%4t%%-13.3f%14t%%-10.3f%24t%%-9.3f%33t%%-9.3f%42t\
+%%-7.2f%49t%%-15.7g%64t%%-15.7g%80t \n"
+define  PSF_MWSTR2  "%4t%-10.3f%-10.3f%-9.3f%-9.3f%-7.2f%-15.7g%-15.7g%80t\\\n"
+
+define  PSF_MNSTR3  "#N%4tIER%9tERROR%80t\\\n"
+define  PSF_MUSTR3  "#U%4t##%9terrors%80t\\\n"
+define  PSF_MFSTR3  "#F%4t%%-8d%9t%%-13s%80t \n"
+define  PSF_MWSTR3  "%4t%-5d%-13.13s%80t \n"
+
+
+# AP_WFRES -- Write the results of the fitpsf task to the output file.
+
+procedure ap_wfres (ap, fd, ier)
+
+pointer	ap	# pointer to apphot structure
+int	fd	# output file descriptor
+int	ier	# comment string
+
+pointer	psf
+
+begin
+	# Initialize.
+	if (fd == NULL)
+	    return
+	psf = AP_PPSF(ap)
+
+	# Print the parameters.
+	switch (AP_PSFUNCTION(psf)) {
+	case AP_RADGAUSS:
+	    call fprintf (fd, PSF_RWSTR1)
+		call pargr (Memr[AP_PPARS(psf)+1])
+		call pargr (Memr[AP_PPARS(psf)+2])
+		call pargr (Memr[AP_PPARS(psf)+3])
+		call pargr (Memr[AP_PPARS(psf)])
+		call pargr (Memr[AP_PPARS(psf)+4])
+	    call fprintf (fd, PSF_RWSTR2)
+		call pargr (Memr[AP_PPERRS(psf)+1])
+		call pargr (Memr[AP_PPERRS(psf)+2])
+		call pargr (Memr[AP_PPERRS(psf)+3])
+		call pargr (Memr[AP_PPERRS(psf)])
+		call pargr (Memr[AP_PPERRS(psf)+4])
+		call pargi (ier)
+	case AP_ELLGAUSS:
+	    call fprintf (fd, PSF_EWSTR1)
+		call pargr (Memr[AP_PPARS(psf)+1])
+		call pargr (Memr[AP_PPARS(psf)+2])
+		call pargr (Memr[AP_PPARS(psf)+3])
+		call pargr (Memr[AP_PPARS(psf)+4])
+		call pargr (Memr[AP_PPARS(psf)+5])
+		call pargr (Memr[AP_PPARS(psf)])
+		call pargr (Memr[AP_PPARS(psf)+6])
+	    call fprintf (fd, PSF_EWSTR2)
+		call pargr (Memr[AP_PPERRS(psf)+1])
+		call pargr (Memr[AP_PPERRS(psf)+2])
+		call pargr (Memr[AP_PPERRS(psf)+3])
+		call pargr (Memr[AP_PPERRS(psf)+4])
+		call pargr (Memr[AP_PPERRS(psf)+5])
+		call pargr (Memr[AP_PPERRS(psf)])
+		call pargr (Memr[AP_PPERRS(psf)+6])
+	    call fprintf (fd, PSF_EWSTR3)
+		call pargi (ier)
+	case AP_MOMENTS:
+	    call fprintf (fd, PSF_MWSTR1)
+		call pargr (Memr[AP_PPARS(psf)+1])
+		call pargr (Memr[AP_PPARS(psf)+2])
+		call pargr (Memr[AP_PPARS(psf)+3])
+		call pargr (Memr[AP_PPARS(psf)+4])
+		call pargr (Memr[AP_PPARS(psf)+5])
+		call pargr (Memr[AP_PPARS(psf)])
+		call pargr (Memr[AP_PPARS(psf)+6])
+	    call fprintf (fd, PSF_MWSTR2)
+		call pargr (Memr[AP_PPERRS(psf)+1])
+		call pargr (Memr[AP_PPERRS(psf)+2])
+		call pargr (Memr[AP_PPERRS(psf)+3])
+		call pargr (Memr[AP_PPERRS(psf)+4])
+		call pargr (Memr[AP_PPERRS(psf)+5])
+		call pargr (Memr[AP_PPERRS(psf)])
+		call pargr (Memr[AP_PPERRS(psf)+6])
+	    call fprintf (fd, PSF_MWSTR3)
+		call pargi (ier)
+	default:
+		;
+	}
+
+	# Print the error message.
+	switch (ier) {
+	case AP_NOPSFAREA:
+	    call pargstr ("OffImage")
+	case AP_PSF_OUTOFBOUNDS:
+	    call pargstr ("EdgeImage")
+	case AP_NPSF_TOO_SMALL:
+	    call pargstr ("TooFewPts")
+	case AP_PSF_SINGULAR:
+	    call pargstr ("Singular")
+	case AP_PSF_NOCONVERGE:
+	    call pargstr ("BadFit")
+	default:
+	    call pargstr ("NoError")
+	}
+end
+
+
+# RADHDR -- Write the column headers for the radial gaussian function.
+
+procedure radhdr (ap, fd)
+
+pointer	ap	# pointer to apphot structure
+int	fd	# output file descriptor
+
+begin
+	# Print the keyword names.
+	call ap_idhdr (ap, fd)
+
+	call fprintf (fd, PSF_RNSTR1)
+	call fprintf (fd, PSF_RUSTR1)
+	call fprintf (fd, PSF_RFSTR1)
+	call fprintf (fd, "#\n")
+
+	call fprintf (fd, PSF_RNSTR2)
+	call fprintf (fd, PSF_RUSTR2)
+	call fprintf (fd, PSF_RFSTR2)
+	call fprintf (fd, "#\n")
+end
+
+
+# ELHDR -- Write the column headers for the elliptical gaussian function.
+
+procedure elhdr (ap, fd)
+
+pointer	ap		# pointer to apphot structure
+int	fd		# output file descriptor
+
+begin
+	# Print the keywords.
+	call ap_idhdr (ap, fd)
+
+	call fprintf (fd, PSF_ENSTR1)
+	call fprintf (fd, PSF_EUSTR1)
+	call fprintf (fd, PSF_EFSTR1)
+	call fprintf (fd, "#\n")
+
+	call fprintf (fd, PSF_ENSTR2)
+	call fprintf (fd, PSF_EUSTR2)
+	call fprintf (fd, PSF_EFSTR2)
+	call fprintf (fd, "#\n")
+
+	call fprintf (fd, PSF_ENSTR3)
+	call fprintf (fd, PSF_EUSTR3)
+	call fprintf (fd, PSF_EFSTR3)
+	call fprintf (fd, "#\n")
+end
+
+
+# MOMHDR -- Write the column headers for the moments function.
+
+procedure momhdr (ap, fd)
+
+pointer	ap		# pointer to apphot structure
+int	fd		# output file descriptor
+
+begin
+	# Print the keywords.
+	call ap_idhdr (ap, fd)
+
+	call fprintf (fd, PSF_MNSTR1)
+	call fprintf (fd, PSF_MUSTR1)
+	call fprintf (fd, PSF_MFSTR1)
+	call fprintf (fd, "#\n")
+
+	call fprintf (fd, PSF_MNSTR2)
+	call fprintf (fd, PSF_MUSTR2)
+	call fprintf (fd, PSF_MFSTR2)
+	call fprintf (fd, "#\n")
+
+	call fprintf (fd, PSF_MNSTR3)
+	call fprintf (fd, PSF_MUSTR3)
+	call fprintf (fd, PSF_MFSTR3)
+	call fprintf (fd, "#\n")
+end
diff --git a/noao/digiphot/apphot/aplib/mkpkg b/noao/digiphot/apphot/aplib/mkpkg
new file mode 100644
index 00000000..a426075f
--- /dev/null
+++ b/noao/digiphot/apphot/aplib/mkpkg
@@ -0,0 +1,102 @@
+# APPHOT Library Tools
+
+$checkout libpkg.a ".."
+$update libpkg.a
+$checkin libpkg.a ".."
+$exit
+
+libpkg.a:
+	apairmass.x	<imhdr.h>		../lib/apphot.h
+	apapcolon.x	<error.h>		../lib/apphot.h
+	aparrays.x	../lib/phot.h	        ../lib/photdef.h       \
+			../lib/apphotdef.h
+	apfree.x	../lib/apphotdef.h
+	apgaperts.x	<lexnum.h>		<ctype.h>
+	apgqverify.x	<ttyset.h>		<fset.h>
+	apgsvw.x	<imio.h>		<imhdr.h>               \
+			<math.h>
+	apgtverify.x	
+	apinit.x	../lib/apphotdef.h	../lib/apphot.h         \
+			../lib/noisedef.h	../lib/noise.h          \
+			../lib/displaydef.h
+	apinpars1.x	../lib/apphot.h		../lib/noise.h          \
+			../lib/find.h           ../lib/display.h
+	apinpars2.x	../lib/display.h	../lib/center.h		\
+			../lib/fitsky.h         ../lib/phot.h           \
+			../lib/polyphot.h
+	apitime.x	../lib/apphot.h		<imhdr.h>
+	apfilter.x	<imhdr.h>		../lib/apphot.h
+	apimbuf.x	../lib/apphotdef.h
+	apmark1.x	<gset.h>		../lib/center.h         \
+			../lib/fitsky.h		../lib/apphot.h         \
+			../lib/phot.h		../lib/polyphot.h	\
+			../lib/radprof.h
+	apmark2.x	<gset.h>		../lib/apphot.h         \
+			../lib/fitpsf.h
+	apnew.x		../lib/apphot.h
+	apnscolon.x	<error.h>		../lib/noise.h
+	apnshow.x	../lib/apphot.h		../lib/noise.h
+	apotime.x	../lib/apphot.h		<imhdr.h>
+	apoutpars1.x	../lib/apphot.h		../lib/noise.h		\
+			../lib/display.h	../lib/find.h
+	apoutpars2.x	../lib/display.h	../lib/center.h		\
+			../lib/fitsky.h		../lib/phot.h           \
+			../lib/polyphot.h
+	apqrad.x	../lib/apphot.h		../lib/center.h         \
+			<mach.h>
+	appadu.x	../lib/noise.h		<imhdr.h>
+	aprcursor1.x	../lib/apphot.h		../lib/noise.h          \
+			../lib/center.h		../lib/fitsky.h         \
+			../lib/phot.h
+	aprcursor2.x	../lib/apphot.h		../lib/fitpsf.h         \
+			../lib/radprof.h
+	aprdnoise.x	../lib/noise.h		<imhdr.h>
+	apset.x
+	apset1.x	../lib/center.h		../lib/centerdef.h      \
+			../lib/fitsky.h		../lib/apphot.h         \
+			../lib/apphotdef.h	../lib/fitskydef.h	\
+			../lib/phot.h		../lib/photdef.h        \
+			../lib/fitpsfdef.h	../lib/fitpsf.h
+	apset2.x	../lib/apphot.h		../lib/apphotdef.h      \
+			../lib/display.h	../lib/polyphot.h       \
+			../lib/radprofdef.h	../lib/radprof.h	\
+			../lib/polyphotdef.h	../lib/noisedef.h       \
+			../lib/noise.h		../lib/finddef.h        \
+			../lib/find.h		../lib/displaydef.h
+	apstat.x
+	apstat1.x	../lib/center.h		../lib/centerdef.h      \
+			../lib/fitsky.h		../lib/apphot.h         \
+			../lib/apphotdef.h	../lib/fitskydef.h	\
+			../lib/phot.h		../lib/photdef.h        \
+			../lib/fitpsfdef.h	../lib/fitpsf.h
+	apstat2.x	../lib/apphot.h		../lib/apphotdef.h      \
+			../lib/display.h	../lib/polyphot.h       \
+			../lib/radprofdef.h	../lib/radprof.h	\
+			../lib/polyphotdef.h	../lib/noisedef.h       \
+			../lib/noise.h		../lib/finddef.h        \
+			../lib/find.h		../lib/displaydef.h
+	apshowplot.x	../lib/apphot.h
+	apverify1.x	<math.h>		../lib/apphot.h         \
+			../lib/center.h		../lib/fitsky.h         \
+			../lib/phot.h		../lib/noise.h
+	apverify2.x	../lib/apphot.h		../lib/fitpsf.h         \
+			../lib/noise.h		../lib/find.h           \
+			../lib/radprof.h
+	apwres1.x	../lib/apphot.h		../lib/find.h		\
+			../lib/center.h		../lib/fitsky.h	        
+	apwres2.x	../lib/apphotdef.h	../lib/photdef.h	\
+			../lib/apphot.h		../lib/fitsky.h		\
+			../lib/phot.h		../lib/polyphot.h
+	apwres3.x	../lib/apphotdef.h	../lib/radprofdef.h	\
+			../lib/apphot.h		../lib/radprof.h
+	apwres4.x	../lib/apphotdef.h	../lib/fitpsfdef.h	\
+			../lib/fitpsf.h         ../lib/apphot.h
+	apwparam1.x	<time.h>		../lib/apphot.h	        \
+			../lib/noise.h		../lib/center.h         \
+			../lib/fitsky.h		../lib/phot.h		\
+			../lib/apphotdef.h
+	apwparam2.x	../lib/apphotdef.h	../lib/polyphot.h       \
+			../lib/radprof.h	../lib/fitpsf.h
+	apimkeys.x	../lib/apphot.h
+	apwcs.x		../lib/apphot.h		<imio.h>
+	;
diff --git a/noao/digiphot/apphot/apphot.cl b/noao/digiphot/apphot/apphot.cl
new file mode 100644
index 00000000..d4b3b94f
--- /dev/null
+++ b/noao/digiphot/apphot/apphot.cl
@@ -0,0 +1,58 @@
+#{ APPHOTX -- Digital aperture photometry package.
+
+dataio			# rfits task required by aptest.cl script
+lists			# lintran task in the lists package
+
+package apphot
+
+task center,
+     daofind,
+     fitpsf,
+     fitsky,
+     radprof,
+     phot,
+     polymark,
+     polyphot,
+     qphot,
+     wphot	= "apphot$x_apphot.e"
+
+task centerpars = "apphot$centerpars.par"
+task datapars   = "apphot$datapars.par"
+task findpars	= "apphot$findpars.par"
+task fitskypars = "apphot$fitskypars.par"
+task photpars   = "apphot$photpars.par"
+task polypars   = "apphot$polypars.par"
+
+task aptest	= "apphot$aptest.cl"
+
+# PTOOLS tasks
+
+task pexamine	= "apphot$x_ptools.e"
+
+task    pconvert,
+        istable,
+        txcalc,
+        txdump,
+        txrenumber,
+        txselect,
+        txsort          = "ptools$x_ptools.e"
+
+task    xyplot          = "ptools$xyplot.par"
+task    histplot        = "ptools$histplot.par"
+task    radplot         = "ptools$radplot.par"
+task    surfplot        = "ptools$surfplot.par"
+task    cntrplot        = "ptools$cntrplot.par"
+
+# PTOOLS scripts which depend on PTOOLS and TTOOLS tasks
+# Note TTOOLS is not loaded
+
+task    pcalc           = "ptools$pcalc.cl"
+task    pdump           = "ptools$pdump.cl"
+task    prenumber       = "ptools$prenumber.cl"
+task    pselect         = "ptools$pselect.cl"
+task    psort           = "ptools$psort.cl"
+
+hidetask    istable, txcalc, txdump, txrenumber, txselect, txsort
+hidetask    xyplot, histplot, radplot, surfplot, cntrplot
+
+clbye()
diff --git a/noao/digiphot/apphot/apphot.hd b/noao/digiphot/apphot/apphot.hd
new file mode 100644
index 00000000..6061b68d
--- /dev/null
+++ b/noao/digiphot/apphot/apphot.hd
@@ -0,0 +1,34 @@
+# Help directory for the APPHOT package
+
+$doc		= "./doc/"
+
+$aptest		= "apphot$aptest/"
+$center		= "apphot$center/"
+$daofind	= "apphot$daofind/"
+$fitpsf		= "apphot$fitpsf/"
+$fitsky		= "apphot$fitsky/"
+$phot		= "apphot$phot/"
+$polyphot	= "apphot$polyphot/"
+$pexamine	= "ptools$pexamine/"
+$radprof	= "apphot$radprof/"
+$wphot		= "apphot$wphot/"
+
+aptest		hlp=doc$aptest.hlp
+center		hlp=doc$center.hlp,		src=center$t_center.x
+centerpars	hlp=doc$centerpars.hlp,		src=apphot$centerpars.par
+daofind		hlp=doc$daofind.hlp,		src=daofind$t_daofind.x
+datapars	hlp=doc$datapars.hlp,		src=apphot$datapars.par
+findpars	hlp=doc$findpars.hlp,		src=apphot$findpars.par
+fitpsf		hlp=doc$fitpsf.hlp,		src=fitpsf$t_fitpsf.x
+fitsky		hlp=doc$fitsky.hlp,		src=fitsky$t_fitsky.x
+fitskypars	hlp=doc$fitskypars.hlp,		src=apphot$fitskypars.par
+pexamine	hlp=doc$pexamine.hlp,		src=pexamine$t_pexamine.x
+phot		hlp=doc$phot.hlp,		src=phot$t_phot.x
+photpars	hlp=doc$photpars.hlp,		src=apphot$photpars.par
+polymark	hlp=doc$polymark.hlp,		src=polyphot$t_polymark.x
+polyphot	hlp=doc$polyphot.hlp,		src=polyphot$t_polyphot.x
+polypars	hlp=doc$polypars.hlp,		src=apphot$polypars.par
+qphot		hlp=doc$qphot.hlp,		src=phot$t_qphot.x
+radprof		hlp=doc$radprof.hlp,		src=radprof$t_radprof.x
+wphot		hlp=doc$wphot.hlp,		src=wphot$t_wphot.x
+revisions	sys=Revisions
diff --git a/noao/digiphot/apphot/apphot.men b/noao/digiphot/apphot/apphot.men
new file mode 100644
index 00000000..e83c00ff
--- /dev/null
+++ b/noao/digiphot/apphot/apphot.men
@@ -0,0 +1,26 @@
+         aptest - Run basic tests on the apphot package tasks
+	 center - Compute accurate centers for a list of objects
+     centerpars - Edit the centering parameters
+	daofind - Find stars in an image using the dao algorithm
+       datapars - Edit the data dependent parameters
+       findpars - Edit the star detection parameters
+	 fitpsf - Model the stellar psf with an analytic function
+         fitsky - Compute sky values in a list of annular or circular regions
+     fitskypars - Edit the sky fitting parameters
+	   phot - Measure magnitudes for a list of stars
+       photpars - Edit the photometry parameters
+       polymark - Create polygon lists for polyphot
+       polyphot - Measure magnitudes inside a list of polygonal regions
+       polypars - Edit the polyphot parameters
+	  qphot - Measure quick magnitudes for a list of stars
+        radprof - Compute the stellar radial profile of a list of stars
+	  wphot - Measure magnitudes for a list of stars with weighting
+
+        lintran - Linearly transform a coordinate list
+          pcalc - Do arithmetic operations on a list of apphot databases
+       pconvert - Convert a text database to a tables database
+          pdump - Print selected fields from a list of apphot databases
+       pexamine - Interactively examine and edit an apphot database
+      prenumber - Renumber stars in an apphot database
+        pselect - Select records from an apphot database
+          psort - Sort an apphot database
diff --git a/noao/digiphot/apphot/apphot.par b/noao/digiphot/apphot/apphot.par
new file mode 100644
index 00000000..ba37d156
--- /dev/null
+++ b/noao/digiphot/apphot/apphot.par
@@ -0,0 +1,11 @@
+# APPHOTX package parameter file
+
+version,s,h,"May00"
+wcsin,s,h,logical,"logical|tv|physical|world",,"The input coordinates wcs"
+wcsout,s,h,logical,"logical|tv|physical",,"The output coordinates wcs"
+cache,b,h,no,,,"Cache image in memory ?"
+verify,b,h,yes,,,"Verify critical parameters ?"
+update,b,h,no,,,"Update critial parameters ?"
+verbose,b,h,no,,,"Print verbose output ?"
+graphics,s,h,stdgraph,,,"Default graphics device"
+display,s,h,stdimage,,,"Default display device"
diff --git a/noao/digiphot/apphot/aptest.cl b/noao/digiphot/apphot/aptest.cl
new file mode 100644
index 00000000..58dad449
--- /dev/null
+++ b/noao/digiphot/apphot/aptest.cl
@@ -0,0 +1,220 @@
+# APTEST - Self testing procedure for the APPHOT package.
+
+procedure aptest (imname)
+
+string 	imname		{prompt="Name of the output test image"}
+string	aplogfile	{"", prompt="Name of the output log file"}
+string	applotfile	{"", prompt="Name of the output plot file"}
+
+begin
+	# Declare local variables.
+	string	im, aplog, applot, apcoords
+
+	# Check that the user truly wants to proceed.
+	s1 = ""
+	print ("")
+	print ("APTEST INITIALIZES THE APPHOT TASK PARAMETERS")
+	print ("TYPE q or Q TO QUIT, ANY OTHER KEY TO PROCEED")
+	if (scan (s1) != EOF) {
+	    if (s1 == "q" || s1 == "Q") {
+		print ("TERMINATING THE APTEST TASK")
+		bye
+	    }
+	}
+	print ("")
+
+	# Define some local variables.
+	im = imname
+	aplog = aplogfile
+	if (aplog == "") {
+	    aplog = im // ".log"
+	}
+	applot = applotfile
+	if (applot == "") {
+	    applot = im // ".plot"
+	}
+
+	# Read in the fits file and check for existance of the log and
+	# plot files.
+	if (! access (im // ".imh") && ! access (im // ".hhh")) {
+	    rfits ("apphot$test/fits3.fits", "0", im, make_image=yes,
+		    long_header=no, short_header=yes, datatype="",blank=0,
+		    scale=yes,oldirafname=no,offset=0, >& "dev$null")
+	} else {
+	    error (0, "Error: The image already exists on disk")
+	}
+	if (access (aplog)) {
+	    error (0, "Error: The log file already exists on disk")
+	}
+	if (access (applot)) {
+	    error (0, "Error: The plot file already exists on disk")
+	}
+
+	# Initialize the APPHOT package.
+	print ("INITIALIZE THE APPHOT PACKAGE", >> aplog)
+	print ("", >> aplog)
+	print ("")
+	print ("INITIALIZE THE APPHOT PACKAGE")
+	print ("")
+
+	unlearn ("txdump")
+	unlearn ("center")
+	unlearn ("centerpars")
+	unlearn ("daofind")
+	unlearn ("datapars")
+	unlearn ("findpars")
+	unlearn ("fitpsf")
+	unlearn ("fitsky")
+	unlearn ("fitskypars")
+	unlearn ("phot")
+	unlearn ("photpars")
+	unlearn ("polymark")
+	unlearn ("polyphot")
+	unlearn ("polypars")
+	unlearn ("qphot")
+	unlearn ("radprof")
+	unlearn ("wphot")
+
+	# Test the DAOFIND task.
+
+	print ("TESTING THE DAOFIND TASK", >> aplog) 
+	print ("TESTING THE DAOFIND TASK") 
+	print ("", >> aplog)
+
+	datapars.fwhmpsf=2.354820
+	datapars.sigma=10.0
+	findpars.threshold=3.0
+
+	apcoords = im // ".coo.1"
+	daofind (im, output=apcoords, interactive-, verify-)
+	concat (apcoords, aplog, append=yes)
+
+	# Test the CENTER task.
+
+	print ("", >> aplog)
+	print ("TESTING THE CENTER TASK", >> aplog) 
+	print ("TESTING THE CENTER TASK") 
+	print ("", >> aplog)
+
+	center (im, coords=apcoords, interactive-, verify-)
+	concat (im // ".ctr.1", aplog, append=yes)
+	delete (im // ".ctr.1", ver-, >& "dev$null")
+
+	# Test the FITSKY task.
+
+	print ("", >> aplog)
+	print ("TESTING THE FITSKY TASK", >> aplog) 
+	print ("TESTING THE FITSKY TASK") 
+	print ("", >> aplog)
+
+	fitskypars.annulus=6.0
+	fitskypars.dannulus=7.0
+
+	fitsky (im, coords=apcoords, interactive-, verify-)
+	concat (im // ".sky.1", aplog, append=yes)
+	delete (im // ".sky.1", ver-, >& "dev$null")
+
+	# Test the QPHOT task.
+
+	print ("", >> aplog)
+	print ("TESTING THE QPHOT TASK", >> aplog) 
+	print ("TESTING THE QPHOT TASK") 
+	print ("", >> aplog)
+
+	qphot (im, 5.0, 6.0, 7.0, "3.0,5.0", coords=apcoords, interactive-)
+	concat (im // ".mag.1", aplog, append=yes)
+	delete (im // ".mag.1", ver-, >& "dev$null")
+
+	# Test the PHOT task.
+
+	print ("", >> aplog)
+	print ("TESTING THE PHOT TASK", >> aplog) 
+	print ("TESTING THE PHOT TASK") 
+	print ("", >> aplog)
+
+	photpars.apertures="3.0,5.0"
+
+	phot (im, coords=apcoords, interactive-, verify-)
+	concat (im // ".mag.1", aplog, append=yes)
+	delete (im // ".mag.1", ver-, >& "dev$null")
+
+	# Test the WPHOT task.
+
+	print ("", >> aplog)
+	print ("TESTING THE WPHOT TASK", >> aplog) 
+	print ("TESTING THE WPHOT TASK") 
+	print ("", >> aplog)
+
+	photpars.weighting="gauss"
+
+	wphot (im, coords=apcoords, interactive-, verify-)
+	concat (im // ".omag.1", aplog, append=yes)
+	delete (im // ".omag.1", ver-, >& "dev$null")
+
+	# Test the POLYPHOT task.
+
+	print ("", >> aplog)
+	print ("TESTING THE POLYPHOT TASK", >> aplog) 
+	print ("TESTING THE POLYPHOT TASK")
+	print ("", >> aplog)
+	print ("COPY OF THE POLYGONS FILE", >> aplog) 
+	print ("", >> aplog)
+	concat ("apphot$test/polygons.dat", aplog, append=yes)
+	print ("", >> aplog)
+
+	polyphot (im, coords=apcoords, polygons="apphot$test/polygons.dat",
+	    interactive-, verify-)
+	concat (im // ".ply.1", aplog, append=yes)
+	delete (im // ".ply.1", ver-, >& "dev$null")
+
+	# Test the RADPROF task.
+
+	print ("", >> aplog)
+	print ("TESTING THE RADPROF TASK", >> aplog) 
+	print ("TESTING THE RADPROF TASK") 
+	print ("", >> aplog)
+
+	radprof (im, 8.0, 0.25, coords=apcoords, output="default",
+	    plotfile=applot, order=4, nreject=3, kreject=3.0, interactive-,
+	    verify-)
+	concat (im // ".prf.1", aplog, append=yes)
+	delete (im // ".prf.1", ver-, >& "dev$null")
+
+	# Test the FITPSF task.
+
+	print ("", >> aplog)
+	print ("TESTING THE FITPSF TASK", >> aplog) 
+	print ("TESTING THE FITPSF TASK") 
+	print ("", >> aplog)
+
+	fitpsf (im, 7.0, coords=apcoords, interactive-, verify-)
+	concat (im // ".psf.1", aplog, append=yes)
+	delete (im // ".psf.1", ver-, >& "dev$null")
+
+	print ("", >> aplog)
+	print ("APPHOT PACKAGE TESTS COMPLETED", >> aplog) 
+	print ("")
+	print ("APPHOT PACKAGE TESTS COMPLETED") 
+	print ("", >> aplog)
+
+	# Clean up.
+	delete (apcoords, ver-, >& "dev$null")
+	unlearn ("txdump")
+	unlearn ("center")
+	unlearn ("centerpars")
+	unlearn ("daofind")
+	unlearn ("datapars")
+	unlearn ("findpars")
+	unlearn ("fitpsf")
+	unlearn ("fitsky")
+	unlearn ("fitskypars")
+	unlearn ("phot")
+	unlearn ("photpars")
+	unlearn ("polymark")
+	unlearn ("polyphot")
+	unlearn ("polypars")
+	unlearn ("qphot")
+	unlearn ("radprof")
+	unlearn ("wphot")
+	bye
+end
diff --git a/noao/digiphot/apphot/aputil/apbsmooth.x b/noao/digiphot/apphot/aputil/apbsmooth.x
new file mode 100644
index 00000000..28c53c00
--- /dev/null
+++ b/noao/digiphot/apphot/aputil/apbsmooth.x
@@ -0,0 +1,33 @@
+# AP_BSMOOTH - Box car smooth a histogram 1, 2 or 3 times.
+
+procedure ap_bsmooth (hgm, shgm, nbins, nker, iter)
+
+real	hgm[ARB]		# the original histogram
+real	shgm[ARB]		# the smoothed histogram
+int	nbins			# length of the histogram
+int	nker			# half width of box kernel
+int	iter			# number of iterations
+
+pointer	sp, work1, work2
+
+begin
+	# Smooth the histogram
+	switch (iter) {
+	case 1:
+	    call ap_sboxr (hgm, shgm, nbins, nker)
+	case 2:
+	    call smark (sp)
+	    call salloc (work1, nbins, TY_REAL)
+	    call ap_sboxr (hgm, Memr[work1], nbins, nker)
+	    call ap_sboxr (Memr[work1], shgm, nbins, nker)
+	    call sfree (sp)
+	default:
+	    call smark (sp)
+	    call salloc (work1, nbins, TY_REAL)
+	    call salloc (work2, nbins, TY_REAL)
+	    call ap_sboxr (hgm, Memr[work1], nbins, nker)
+	    call ap_sboxr (Memr[work1], Memr[work2], nbins, nker)
+	    call ap_sboxr (Memr[work2], shgm, nbins, nker)
+	    call sfree (sp)
+	}
+end
diff --git a/noao/digiphot/apphot/aputil/apclip.x b/noao/digiphot/apphot/aputil/apclip.x
new file mode 100644
index 00000000..62a52c30
--- /dev/null
+++ b/noao/digiphot/apphot/aputil/apclip.x
@@ -0,0 +1,23 @@
+# AP_CLIP -- Clip the ends of a sorted pixel distribution by a certain
+# percent.
+
+int procedure ap_clip (skypix, index, npix, loclip, hiclip, loindex, hiindex)
+
+real	skypix[ARB]		# the unsorted array of sky pixels
+int	index[ARB]		# the array of sorted indices
+int	npix			# the number of sky pixels
+real	loclip, hiclip		# the clipping factors in percent
+int	loindex, hiindex	# the clipping indices
+
+begin
+	# Sort the pixels.
+	call apqsort (skypix, index, index, npix)
+
+	# Determine the clipping factors.
+	loindex = nint (0.01 * loclip * npix) + 1
+	hiindex = npix - nint (0.01 * hiclip * npix)
+	if ((hiindex - loindex + 1) <= 0)
+	    return (npix)
+	else
+	    return (loindex - 1 + npix - hiindex)
+end
diff --git a/noao/digiphot/apphot/aputil/apdate.x b/noao/digiphot/apphot/aputil/apdate.x
new file mode 100644
index 00000000..21faea88
--- /dev/null
+++ b/noao/digiphot/apphot/aputil/apdate.x
@@ -0,0 +1,29 @@
+include <time.h>
+
+# APDATE -- Fetch the date and time strings required for the apphot output
+# files.
+
+procedure apdate (date, time, maxch)
+
+char	date[ARB]	# the date string
+char	time[ARB]	# the time string
+int	maxch		# the maximum number of character in the string
+
+int	tm[LEN_TMSTRUCT]
+long	ctime
+long	clktime()
+#long	lsttogmt()
+
+begin
+	ctime = clktime (long(0))
+	#ctime = lsttogmt (ctime)
+	call brktime (ctime, tm)
+	call sprintf (date, maxch, "%04d-%02d-%02d")
+	    call pargi (TM_YEAR(tm))
+	    call pargi (TM_MONTH(tm))
+	    call pargi (TM_MDAY(tm))
+	call sprintf (time, maxch, "%02d:%02d:%02d")
+	    call pargi (TM_HOUR(tm))
+	    call pargi (TM_MIN(tm))
+	    call pargi (TM_SEC(tm))
+end
diff --git a/noao/digiphot/apphot/aputil/apdiverr.x b/noao/digiphot/apphot/aputil/apdiverr.x
new file mode 100644
index 00000000..d3c36444
--- /dev/null
+++ b/noao/digiphot/apphot/aputil/apdiverr.x
@@ -0,0 +1,7 @@
+# AP_DIVERR -- Error condition procedure which returns a value of unity.
+
+real procedure ap_diverr ()
+
+begin
+	return (1.0)
+end
diff --git a/noao/digiphot/apphot/aputil/apfnames.x b/noao/digiphot/apphot/aputil/apfnames.x
new file mode 100644
index 00000000..95e56167
--- /dev/null
+++ b/noao/digiphot/apphot/aputil/apfnames.x
@@ -0,0 +1,280 @@
+
+# APINNAME -- Construct an apphot input file name.
+# If input is null or a directory, a name is constructed from the root
+# of the image name and the extension. The disk is searched to avoid
+# name collisions.
+
+procedure apinname (image, input, ext, name, maxch)
+
+char	image[ARB]		# image name
+char	input[ARB]		# input directory or name
+char	ext[ARB]		# extension
+char	name[ARB]		# input name
+int	maxch			# maximum size of name
+
+int	ndir, nimdir, clindex, clsize
+pointer	sp, root, str
+int	fnldir(), strlen()
+
+begin
+	call smark (sp)
+	call salloc (root, SZ_FNAME, TY_CHAR)
+	call salloc (str, SZ_FNAME, TY_CHAR)
+
+	ndir = fnldir (input, name, maxch)
+	if (strlen (input) == ndir) {
+            call imparse (image, Memc[root], SZ_FNAME, Memc[str], SZ_FNAME,
+                Memc[str], SZ_FNAME, clindex, clsize)
+            nimdir = fnldir (Memc[root], Memc[str], SZ_FNAME)
+            if (clindex >= 0) {
+                call sprintf (name[ndir+1], maxch, "%s%d.%s.*")
+                    call pargstr (Memc[root+nimdir])
+                    call pargi (clindex)
+                    call pargstr (ext)
+            } else {
+                call sprintf (name[ndir+1], maxch, "%s.%s.*")
+                    call pargstr (Memc[root+nimdir])
+                    call pargstr (ext)
+            }
+	    call apiversion (name, name, maxch)
+	} else
+	    call strcpy (input, name, maxch)
+
+	call sfree (sp)
+end
+
+
+# APOUTNAME -- Construct an apphot output file name.
+# If output is null or a directory, a name is constructed from the root
+# of the image name and the extension. The disk is searched to avoid
+# name collisions.
+
+procedure apoutname (image, output, ext, name, maxch)
+
+char	image[ARB]		# image name
+char	output[ARB]		# output directory or name
+char	ext[ARB]		# extension
+char	name[ARB]		# output name
+int	maxch			# maximum size of name
+
+int	ndir, nimdir, clindex, clsize
+pointer	sp, root, str
+int	fnldir(), strlen()
+
+begin
+	call smark (sp)
+	call salloc (root, SZ_FNAME, TY_CHAR)
+	call salloc (str, SZ_FNAME, TY_CHAR)
+
+	ndir = fnldir (output, name, maxch)
+	if (strlen (output) == ndir) {
+            call imparse (image, Memc[root], SZ_FNAME, Memc[str], SZ_FNAME,
+                Memc[str], SZ_FNAME, clindex, clsize)
+            nimdir = fnldir (Memc[root], Memc[str], SZ_FNAME)
+            if (clindex >= 0) {
+                call sprintf (name[ndir+1], maxch, "%s%d.%s.*")
+                    call pargstr (Memc[root+nimdir])
+                    call pargi (clindex)
+                    call pargstr (ext)
+            } else {
+                call sprintf (name[ndir+1], maxch, "%s.%s.*")
+                    call pargstr (Memc[root+nimdir])
+                    call pargstr (ext)
+            }
+	    call apoversion (name, name, maxch)
+	} else
+	    call strcpy (output, name, maxch)
+
+	call sfree (sp)
+end
+
+
+# APTMPIMAGE -- Generate a temporary image name either by calling a system
+# routine or by appending the image name to a user specified prefix.
+
+int procedure aptmpimage (image, prefix, tmp, name, maxch)
+
+char	image[ARB]		# image name
+char	prefix[ARB]		# user supplied prefix
+char	tmp[ARB]		# user supplied temporary root
+char	name[ARB]		# output name
+int	maxch			# max number of chars
+
+int	npref, ndir, nimdir, clindex, clsize
+pointer sp, root, str
+int	fnldir(), strlen()
+
+begin
+	npref = strlen (prefix)
+	ndir = fnldir (prefix, name, maxch)
+	if (npref == ndir) {
+	    call mktemp (tmp, name[ndir+1], maxch)
+	    return (NO)
+	} else {
+	    call smark (sp)
+	    call salloc (root, SZ_FNAME, TY_CHAR)
+	    call salloc (str, SZ_FNAME, TY_CHAR)
+	    call strcpy (prefix, name, npref)
+	    call imparse (image, Memc[root], SZ_FNAME, Memc[str], SZ_FNAME,
+	        Memc[str], SZ_FNAME, clindex, clsize)
+		nimdir = fnldir (Memc[root], Memc[str], SZ_FNAME)
+	    if (clindex >= 0) {
+	        call sprintf (name[npref+1], maxch, "%s%d")
+		    call pargstr (Memc[root+nimdir])
+		    call pargi (clindex)
+	    } else {
+	        call sprintf (name[npref+1], maxch, "%s")
+		    call pargstr (Memc[root+nimdir])
+	    }
+	    call sfree (sp)
+	    return (YES)
+	}
+end
+
+
+# APIMROOT -- Fetch the root image name minus the directory specification
+# and the section notation.
+
+procedure apimroot (image, root, maxch)
+
+char	image[ARB]		# image specification
+char	root[ARB]		# output root name
+int	maxch			# maximum number of characters
+
+pointer	sp, imroot, kernel, section, str
+int	clindex, clsize, nchars
+int	fnldir()
+
+begin
+	call smark (sp)
+	call salloc (imroot, SZ_PATHNAME, TY_CHAR)
+	call salloc (kernel, SZ_FNAME, TY_CHAR)
+	call salloc (section, SZ_FNAME, TY_CHAR)
+	call salloc (str, SZ_PATHNAME, TY_CHAR)
+
+        call imparse (image, Memc[imroot], SZ_PATHNAME, Memc[kernel], SZ_FNAME,
+            Memc[section], SZ_FNAME, clindex, clsize)
+	nchars = fnldir (Memc[imroot], Memc[str], SZ_PATHNAME)
+	if (clindex >= 0) {
+	    call sprintf (root, maxch, "%s[%d]%s%s")
+	        call pargstr (Memc[imroot+nchars])
+		call pargi (clindex)
+	        call pargstr (Memc[kernel])
+	        call pargstr (Memc[section])
+	} else {
+	    call sprintf (root, maxch, "%s%s%s")
+	        call pargstr (Memc[imroot+nchars])
+	        call pargstr (Memc[kernel])
+	        call pargstr (Memc[section])
+	}
+
+	call sfree (sp)
+end
+
+
+
+# APFROOT -- Fetch the file name minus the directory specification,
+
+procedure apfroot (filename, root, maxch)
+
+char	filename[ARB]		# input file name 
+char	root[ARB]		# output root file name
+int	maxch			# maximum number of characters
+
+pointer	sp, str
+int	nchars
+int	fnldir()
+
+begin
+	call smark (sp)
+	call salloc (str, SZ_PATHNAME, TY_CHAR)
+
+	nchars = fnldir (filename, Memc[str], SZ_PATHNAME)
+	call strcpy (filename[nchars+1], root, maxch)
+
+	call sfree (sp)
+end
+
+
+# APOVERSION -- Compute the next available version number of a given file
+# name template and output the new file name.
+
+procedure apoversion (template, filename, maxch)
+
+char	template[ARB]			# name template
+char	filename[ARB]			# output name
+int	maxch				# maximum number of characters
+
+char	period
+int	newversion, version, len
+pointer	sp, list, name
+int	fntgfnb() strldx(), ctoi(), fntopnb()
+
+begin
+	# Allocate temporary space
+	call smark (sp)
+	call salloc (name, maxch, TY_CHAR)
+	period = '.'
+	list = fntopnb (template, NO)
+
+	# Loop over the names in the list searchng for the highest version.
+	newversion = 0
+	while (fntgfnb (list, Memc[name], maxch) != EOF) {
+	    len = strldx (period, Memc[name])
+	    len = len + 1
+	    if (ctoi (Memc[name], len, version) <= 0)
+		next
+	    newversion = max (newversion, version)
+	}
+
+	# Make new output file name.
+	len = strldx (period, template)
+	call strcpy (template, filename, len)
+	call sprintf (filename[len+1], maxch, "%d")
+	    call pargi (newversion + 1)
+
+	call fntclsb (list)
+	call sfree (sp)
+end
+
+
+# APIVERSION -- Compute the highest available version number of a given file
+# name template and output the file name.
+
+procedure apiversion (template, filename, maxch)
+
+char	template[ARB]			# name template
+char	filename[ARB]			# output name
+int	maxch				# maximum number of characters
+
+char	period
+int	newversion, version, len
+pointer	sp, list, name
+int	fntgfnb() strldx(), ctoi(), fntopnb()
+
+begin
+	# Allocate temporary space
+	call smark (sp)
+	call salloc (name, maxch, TY_CHAR)
+	period = '.'
+	list = fntopnb (template, NO)
+
+	# Loop over the names in the list searchng for the highest version.
+	newversion = 0
+	while (fntgfnb (list, Memc[name], maxch) != EOF) {
+	    len = strldx (period, Memc[name])
+	    len = len + 1
+	    if (ctoi (Memc[name], len, version) <= 0)
+		next
+	    newversion = max (newversion, version)
+	}
+
+	# Make new output file name.
+	len = strldx (period, template)
+	call strcpy (template, filename, len)
+	call sprintf (filename[len+1], maxch, "%d")
+	    call pargi (newversion)
+
+	call fntclsb (list)
+	call sfree (sp)
+end
diff --git a/noao/digiphot/apphot/aputil/apgscur.x b/noao/digiphot/apphot/aputil/apgscur.x
new file mode 100644
index 00000000..5cc8a6df
--- /dev/null
+++ b/noao/digiphot/apphot/aputil/apgscur.x
@@ -0,0 +1,88 @@
+include <gset.h>
+include <fset.h>
+
+# APGSCUR -- Read the x and y coordinates of an object from a file and move
+# the cursor to those coordinates.
+
+int procedure apgscur (sl, gd, xcur, ycur, prev_num, req_num, num)
+
+int	sl		# coordinate file descriptor
+pointer	gd		# pointer to graphics stream
+real	xcur, ycur	# x cur and y cur
+int	prev_num	# previous number
+int	req_num		# requested number
+int	num		# list number
+
+int	stdin, nskip, ncount
+pointer	sp, fname
+int	fscan(), nscan(), strncmp()
+errchk	greactivate, gdeactivate, gscur
+
+begin
+	if (sl == NULL)
+	    return (EOF)
+
+	call smark (sp)
+	call salloc (fname, SZ_FNAME, TY_CHAR)
+
+	# Find the number of objects to be skipped.
+	call fstats (sl, F_FILENAME, Memc[fname], SZ_FNAME)
+	if (strncmp ("STDIN", Memc[fname], 5) == 0) {
+	    stdin = YES
+	    nskip = 1
+	} else {
+	    stdin = NO
+	    if (req_num <= prev_num) {
+		call seek (sl, BOF)
+		nskip = req_num
+	    } else
+		nskip = req_num - prev_num
+	}
+
+	# Initialize.
+	ncount = 0
+	num = prev_num
+
+	# Read the coordinates and write the cursor.
+	repeat {
+
+	    # Print the prompt if file is STDIN.
+	    if (stdin == YES) {
+		call printf ("Type object x and y coordinates: ")
+		call flush (STDOUT)
+	    }
+
+	    # Fetch the coordinates.
+	    if (fscan (sl) != EOF) {
+		call gargr (xcur)
+		call gargr (ycur)
+		if (nscan () == 2) {
+		    ncount = ncount + 1
+		    num = num + 1
+		}
+	    } else 
+		ncount = EOF
+
+	    # Move the cursor.
+	    if (gd != NULL && (ncount == nskip || ncount == EOF)) {
+		iferr {
+		    call greactivate (gd, 0)
+	            call gscur (gd, xcur, ycur)
+		    call gdeactivate (gd, 0)
+		} then
+		    ;
+	    }
+
+	} until (ncount == EOF || ncount == nskip)
+
+	call sfree (sp)
+
+	if (ncount == EOF) {
+	    return (EOF)
+	} else if (nskip == req_num) {
+	    num = ncount
+	    return (ncount)
+	} else {
+	    return (num)
+	}
+end
diff --git a/noao/digiphot/apphot/aputil/apgtools.x b/noao/digiphot/apphot/aputil/apgtools.x
new file mode 100644
index 00000000..e35cb543
--- /dev/null
+++ b/noao/digiphot/apphot/aputil/apgtools.x
@@ -0,0 +1,141 @@
+include <gset.h>
+include <pkg/gtools.h>
+
+# AP_GTINIT -- Initialize the gtools package for the apphot routines.
+
+pointer procedure ap_gtinit (image, wx, wy)
+
+char	image[ARB]	# the image name
+real	wx, wy		# center of sky subraster
+
+pointer	sp, gt, str
+pointer	gt_init()
+
+begin
+	# Allocate working space.
+    	gt = gt_init ()
+	call smark (sp)
+	call salloc (str, SZ_LINE, TY_CHAR)
+
+	# Set the plot title.
+	call sprintf (Memc[str], SZ_LINE, "Image: %s:  %.2f %.2f\n")
+	    call pargstr (image)
+	    call pargr (wx)
+	    call pargr (wy)
+	call gt_sets (gt, GTTITLE, Memc[str])
+
+	call sfree (sp)
+	return (gt)
+end
+
+
+# AP_GTFREE -- Free the gtools package.
+
+procedure ap_gtfree (gt)
+
+pointer	gt		# pointer to gtools structure
+
+begin
+	call gt_free (gt)
+end
+
+
+# AP_PLOTRAD -- Plot the radial profile of a list of pixels.
+
+procedure ap_plotrad (gd, gt, r, i, npts, polymark) 
+
+pointer	gd		# pointer to graphics stream
+pointer	gt		# the GTOOLS pointer
+real	r[ARB]		# the radii array
+real	i[ARB]		# the intensity array
+int	npts		# number of points
+char	polymark[ARB]	# polyline type
+
+begin
+	call gt_sets (gt, GTTYPE, "mark")
+	call gt_sets (gt, GTMARK, polymark)
+	call gt_plot (gd, gt, r, i, npts)
+end
+
+
+# AP_PLOTPTS -- Plot the radial profile of a list of pixels excluding points
+# that are outside the plotting window altogether.
+
+procedure ap_plotpts (gd, gt, r, i, npts, xmin, xmax, ymin, ymax, polymark) 
+
+pointer	gd		# pointer to graphics stream
+pointer	gt		# the GTOOLS pointer
+real	r[ARB]		# the radii array
+real	i[ARB]		# the intensity array
+int	npts		# number of points
+real	xmin, xmax	# the x plot limits
+real	ymin, ymax	# the y plot limits
+char	polymark[ARB]	# polyline type
+
+int	j
+
+begin
+	call gt_sets (gt, GTTYPE, "mark")
+	call gt_sets (gt, GTMARK, polymark)
+	do j = 1, npts {
+	    if (r[j] < xmin || r[j] > xmax)
+		next
+	    if (i[j] < ymin || i[j] > ymax)
+		next
+	    call gt_plot (gd, gt, r[j], i[j], 1)
+	    
+	}
+end
+
+
+# AP_RSET -- Set up the parameters for the radial profile plot.
+
+procedure ap_rset (gd, gt, xmin, xmax, ymin, ymax, xscale)
+
+pointer	gd		# pointer to GRAPHICS stream
+pointer	gt		# pointer to GTOOLS structure
+real	xmin, xmax	# min and max of x vector
+real	ymin, ymax	# min and max of y vector
+real	xscale		# image scale
+
+pointer	sp, str, title
+real	vx1, vx2, vy1, vy2, aspect
+real	gstatr()
+
+begin
+	call smark (sp)
+	call salloc (title, 3 * SZ_LINE, TY_CHAR)
+	call salloc (str, SZ_LINE, TY_CHAR)
+
+	# Reset the aspect ratio.
+	aspect = gstatr (gd, G_ASPECT)
+	call gsetr (gd, G_ASPECT, 0.75)
+
+	# Construct the title.
+	call sysid (Memc[title], 3 * SZ_LINE)
+	call strcat ("\n", Memc[title], 3 * SZ_LINE)
+	call gt_gets (gt, GTTITLE, Memc[str], SZ_LINE) 
+	call strcat (Memc[str], Memc[title], 3 * SZ_LINE)
+	call strcat ("\n\n", Memc[title], 3 * SZ_LINE)
+
+	# Draw three axes.
+	call gseti (gd, G_XDRAWAXES, 2)
+	call gswind (gd, xmin / xscale, xmax / xscale, ymin, ymax)
+	call glabax (gd, Memc[title], "", "Intensity") 
+
+	# Draw the bottom x axis 
+	call gseti (gd, G_YDRAWAXES, 0)
+	call gseti (gd, G_XDRAWAXES, 1)
+	call ggview (gd, vx1, vx2, vy1, vy2)
+	call gsview (gd, vx1, vx2, vy1, vy2)
+	call gswind (gd, xmin, xmax, ymin, ymax)
+	call glabax (gd, "",
+	    "Radial Distance (lower-pixels, upper-scale units)", "")
+
+	# Reset to standard gio parameters.
+	call gseti (gd, G_YDRAWAXES, 3)
+	call gseti (gd, G_XDRAWAXES, 3)
+	call gsetr (gd, G_ASPECT, aspect)
+
+	call sfree (sp)
+end
diff --git a/noao/digiphot/apphot/aputil/aplucy.x b/noao/digiphot/apphot/aputil/aplucy.x
new file mode 100644
index 00000000..f70a39ed
--- /dev/null
+++ b/noao/digiphot/apphot/aputil/aplucy.x
@@ -0,0 +1,47 @@
+# AP_LUCY_SMOOTH - Lucy smooth a histogram with a box shaped function.
+
+procedure ap_lucy_smooth (hgm, shgm, nbins, nker, iter)
+
+real	hgm[ARB]		# the original histogram
+real	shgm[ARB]		# smoothed histogram
+int	nbins			# length of the histogram
+int	nker			# length of box kernel
+int	iter			# number of iterations
+
+int	i, j, nsmooth
+pointer	sp, work1, work2
+real	ap_diverr()
+
+begin
+	# Allocate space and clear the work arrays.
+	call smark (sp)
+	call salloc (work1, nbins, TY_REAL)
+	call salloc (work2, nbins, TY_REAL)
+	call aclrr (Memr[work1], nbins)
+	call aclrr (Memr[work2], nbins)
+	call aclrr (shgm, nbins)
+
+	# Compute the smoothing length and initialize output array.
+	nsmooth = nbins - nker + 1
+	#call ap_aboxr (hgm, shgm[1+nker/2], nsmooth, nker)
+	call ap_sboxr (hgm, shgm, nbins, nker)
+
+	# Iterate on the solution.
+	do i = 1, iter {
+	    #call ap_aboxr (shgm, Memr[work1+nker/2], nsmooth, nker)
+	    call ap_sboxr (shgm, Memr[work1], nbins, nker)
+	    #do j = 1 + nker / 2, nsmooth + nker / 2 {
+	    do j = 1, nbins {
+		if (Memr[work1+j-1] == 0.0)
+		    Memr[work1+j-1] = ap_diverr ()
+		else
+		    #Memr[work1+j-1] = hgm[j] / Memr[work1+j-1]
+		    Memr[work1+j-1] = shgm[j] / Memr[work1+j-1]
+	    }
+	    #call ap_aboxr (Memr[work1], Memr[work2+nker/2], nsmooth, nker)
+	    call ap_sboxr (Memr[work1], Memr[work2], nbins, nker)
+	    call amulr (shgm, Memr[work2], shgm, nbins)
+	}
+
+	call sfree (sp)
+end
diff --git a/noao/digiphot/apphot/aputil/apmapr.x b/noao/digiphot/apphot/aputil/apmapr.x
new file mode 100644
index 00000000..0d4159ab
--- /dev/null
+++ b/noao/digiphot/apphot/aputil/apmapr.x
@@ -0,0 +1,21 @@
+# APMAPR -- Vector linear transformation.  Map the range of pixel values
+# a1, a2 from a into the range b1, b2 into b.  It is assumed that a1 < a2
+# and b1 < b2.
+
+real procedure apmapr (a, a1, a2, b1, b2)
+
+real	a		# the value to be mapped
+real	a1, a2		# the numbers specifying the input data range
+real	b1, b2		# the numbers specifying the output data range
+
+real	minout, maxout, aoff, boff
+real	scalar
+
+begin
+	scalar = (real (b2) - real (b1)) / (real (a2) - real (a1))
+	minout = min (b1, b2)
+	maxout = max (b1, b2)
+	aoff = a1
+	boff = b1
+	return (max(minout, min(maxout, real((a - aoff) * scalar) + boff)))
+end
diff --git a/noao/digiphot/apphot/aputil/apmeds.x b/noao/digiphot/apphot/aputil/apmeds.x
new file mode 100644
index 00000000..0a206c8a
--- /dev/null
+++ b/noao/digiphot/apphot/aputil/apmeds.x
@@ -0,0 +1,154 @@
+# APSMED -- Compute the averaged median given a sorted array and an averaging
+# half width.
+
+real procedure apsmed (pix, index, npts, medcut)
+
+real	pix[ARB]	# array of sky pixels
+int	index[ARB]	# sorted index array
+int	npts		# number of pixels
+int	medcut		# averaging half width
+
+int	med, j, nmed, medlo, medhi
+real	sumed
+
+begin
+	med = (npts + 1) / 2
+	if (mod (med, 2) == 1) {
+	    medlo = max (1, med - medcut)
+	    medhi = min (npts, med + medcut)
+	} else {
+	    medlo = max (1, med - medcut)
+	    medhi = min (npts, med + medcut + 1)
+	}
+
+	sumed = 0.0
+	nmed = 0
+	do j = medlo, medhi {
+	    sumed = sumed + pix[index[j]]
+	    nmed = nmed + 1
+	}
+
+	return (sumed / nmed)
+end
+
+
+# APIMED -- Compute the index of new median value. Weight is an arbitrary
+# weight array which is assumed to be zero if the pixels has been rejected
+# and is positive otherwise.
+
+int procedure apimed (weight, index, lo, hi, nmed)
+
+real	weight[ARB]		# array of weights
+int	index[ARB]		# array of sorted indices
+int	lo, hi			# ranges of weights
+int	nmed			# number of good sky pixels
+
+int	npts, med
+
+begin
+	npts = 0
+	for (med = lo; med <= hi && npts < nmed; med = med + 1) {
+	    if (weight[index[med]] > 0.0)
+		npts = npts + 1
+	}
+
+	if (npts == 0)
+	    return (0)
+	else
+	    return (med)
+end
+
+
+# APWSMED -- Compute the new averaged median given a sorted input array,
+# an averaging half-width, and assuming that there has been pixel rejection.
+
+real procedure apwsmed (pix, index, weight, npix, med, medcut)
+
+real	pix[ARB]		# pixel values array
+int	index[ARB]		# sorted indices array
+real	weight[ARB]		# the weights array
+int	npix			# number of pixels
+int	med			# index of median value
+int	medcut			# of median cut
+
+int	j, nmed, maxmed
+real	sumed
+
+begin
+	sumed = pix[index[med]]
+	if (mod (med, 2) == 1)
+	    maxmed = 2 * medcut + 1 
+	else
+	    maxmed = 2 * medcut + 2 
+
+	nmed = 1
+	for (j = med - 1; j >= 1; j = j - 1) {
+	    if (nmed >=  medcut + 1)
+		break
+	    if (weight[index[j]] > 0.0) {
+		sumed = sumed + pix[index[j]]
+		nmed = nmed + 1
+	    }
+	}
+	for (j = med + 1; j <= npix; j = j + 1) {
+	    if (nmed >= maxmed)
+		break
+	    if (weight[index[j]] > 0.0) {
+		sumed = sumed + pix[index[j]]
+		nmed = nmed + 1
+	    }
+	}
+
+	return (sumed / nmed)
+end
+
+
+# APMEDR -- Vector median selection. The selection is carried out in a temporary
+# array, leaving the input vector unmodified.  Especially demanding applications
+# may wish to call the asok routine directory to avoid the call to the memory
+# allocator.
+
+real procedure apmedr (a, index, npix)
+
+real	a[ARB]				# input array of values
+int	index[ARB]			# sorted index array
+int	npix				# number of pixels
+
+int	i
+pointer	sp, aa
+real	median
+real	asokr()		# select the Kth smallest element from A
+
+begin
+	switch (npix) {
+	case 1, 2:
+	    return (a[1])
+
+	case 3:
+	    if (a[1] < a[2]) {
+		if (a[2] < a[3])
+		    return (a[2])
+		else if (a[1] < a[3])
+		    return (a[3])
+		else
+		    return (a[1])
+	    } else {
+		if (a[2] > a[3])
+		    return (a[2])
+		else if (a[1] < a[3])
+		    return (a[1])
+		else
+		    return (a[3])
+	    }
+
+	default:
+	    call smark (sp)
+	    call salloc (aa, npix, TY_REAL)
+	    do i = 1, npix
+		Memr[aa+i-1] = a[index[i]]
+	    median = asokr (Memr[aa], npix, (npix + 1) / 2)
+	    call sfree (sp)
+
+	    return (median)
+	}
+end
diff --git a/noao/digiphot/apphot/aputil/apmoments.x b/noao/digiphot/apphot/aputil/apmoments.x
new file mode 100644
index 00000000..5a1bfbd4
--- /dev/null
+++ b/noao/digiphot/apphot/aputil/apmoments.x
@@ -0,0 +1,138 @@
+# APMOMENTS -- Procedure to compute the first three moments of a
+# distribution given the appropriate sums.
+
+procedure apmoments (sumpx, sumsqpx, sumcbpx, npix, sky_zero, mean, sigma, skew)
+
+double	sumpx		# sum of the pixels
+double	sumsqpx		# sum of pixels squared
+double	sumcbpx		# sum of cubes of pixels
+int	npix		# number of pixels
+real	sky_zero	# sky zero point for moment analysis
+real	mean		# mean of pixels
+real	sigma		# sigma of pixels
+real	skew		# skew of pixels
+
+double	dmean, dsigma, dskew
+
+begin
+	# Recompute the moments.
+	dmean = sumpx / npix
+	dsigma = sumsqpx / npix - dmean ** 2
+	if (dsigma <= 0.0d0) {
+	    sigma = 0.0
+	    skew = 0.0
+	} else {
+	    dskew = sumcbpx / npix - 3.0d0 * dmean * dsigma - dmean ** 3
+	    sigma = sqrt (dsigma)
+	    if (dskew < 0.0d0)
+	        skew = - (abs (dskew) ** (1.0d0 / 3.0d0))
+	    else if (dskew > 0.0d0)
+	        skew = dskew ** (1.0d0 / 3.0d0)
+	    else
+		skew = 0.0
+	}
+	mean = sky_zero + dmean
+end
+
+
+# APFMOMENTS -- Procedure to compute the first three moments of a distribution
+# given the data. The sums are returned as well.
+
+procedure apfmoments (pix, npix, sky_zero, sumpx, sumsqpx, sumcbpx, mean,
+	sigma, skew)
+
+real	pix[npix]	# array of pixels
+int	npix		# number of pixels
+real	sky_zero	# sky zero point for moment analysis
+double	sumpx		# sum of the pixels
+double	sumsqpx		# sum of pixels squared
+double	sumcbpx		# sum of cubes of pixels
+real	mean		# mean of pixels
+real	sigma		# sigma of pixels
+real	skew		# skew of pixels
+
+double	dpix, dmean, dsigma, dskew
+int	i
+
+begin
+	# Zero and accumulate the sums.
+	sumpx = 0.0d0
+	sumsqpx = 0.0d0
+	sumcbpx = 0.0d0
+	do i = 1, npix {
+	    dpix = pix[i] - sky_zero
+	    sumpx = sumpx + dpix
+	    sumsqpx = sumsqpx + dpix * dpix
+	    sumcbpx = sumcbpx + dpix * dpix * dpix
+	}
+
+	# Compute the moments.
+	dmean = sumpx / npix
+	dsigma = sumsqpx / npix - dmean ** 2
+	if (dsigma <= 0.0) {
+	    sigma = 0.0
+	    skew = 0.0
+	} else {
+	    dskew = sumcbpx / npix - 3.0d0 * dmean * dsigma - dmean ** 3
+	    sigma = sqrt (dsigma)
+	    if (dskew < 0.0d0)
+	        skew = - (abs (dskew) ** (1.0d0 / 3.0d0))
+	    else if (dskew > 0.0d0)
+	        skew = dskew ** (1.0d0 / 3.0d0)
+	    else
+		skew = 0.0
+	}
+	mean = sky_zero + dmean
+end
+
+
+# APFIMOMENTS -- Procedure to compute the first three moments of a distribution
+# given the data. The sums are returned as well.
+
+procedure apfimoments (pix, index, npix, sky_zero, sumpx, sumsqpx, sumcbpx,
+	mean, sigma, skew)
+
+real	pix[ARB]	# array of pixels
+int	index[ARB]	# the index array
+int	npix		# number of pixels
+real	sky_zero	# sky zero point for moment analysis
+double	sumpx		# sum of the pixels
+double	sumsqpx		# sum of pixels squared
+double	sumcbpx		# sum of cubes of pixels
+real	mean		# mean of pixels
+real	sigma		# sigma of pixels
+real	skew		# skew of pixels
+
+double	dpix, dmean, dsigma, dskew
+int	i
+
+begin
+	# Zero and accumulate the sums.
+	sumpx = 0.0d0
+	sumsqpx = 0.0d0
+	sumcbpx = 0.0d0
+	do i = 1, npix {
+	    dpix = pix[index[i]] - sky_zero
+	    sumpx = sumpx + dpix
+	    sumsqpx = sumsqpx + dpix * dpix
+	    sumcbpx = sumcbpx + dpix * dpix * dpix
+	}
+
+	# Compute the moments.
+	dmean = sumpx / npix
+	dsigma = sumsqpx / npix - dmean ** 2
+	if (dsigma <= 0.0d0) {
+	    sigma = 0.0
+	    skew = 0.0
+	} else {
+	    dskew = sumcbpx / npix - 3.0d0 * dmean * dsigma - dmean ** 3
+	    sigma = sqrt (dsigma)
+	    if (dskew < 0.0d0)
+	        skew = - (abs (dskew) ** (1.0d0 / 3.0d0))
+	    else if (dskew > 0.0d0)
+	        skew = dskew ** (1.0d0 / 3.0d0)
+	    else
+		skew = 0.0
+	}
+	mean = dmean + sky_zero
+end
diff --git a/noao/digiphot/apphot/aputil/apnlfuncs.x b/noao/digiphot/apphot/aputil/apnlfuncs.x
new file mode 100644
index 00000000..290b9e90
--- /dev/null
+++ b/noao/digiphot/apphot/aputil/apnlfuncs.x
@@ -0,0 +1,375 @@
+
+include	<math.h>
+include	<mach.h>
+
+# CGAUSS1D - Compute the value of a 1-D Gaussian function  on a constant
+# background.
+
+procedure cgauss1d (x, nvars, p, np, z)
+
+real	x[ARB]		# variables, x[1] = position coordinate
+int	nvars		# the number of variables, not used
+real	p[ARB]		# p[1]=amplitude p[2]=center p[3]=variance p[4]=sky
+int	np		# number of parameters np = 4
+real	z		# function return
+
+real	r2
+
+begin
+	if (p[3] == 0.)
+	    r2 = 36.0
+	else
+	    r2 = (x[1] - p[2]) ** 2 / (2. * p[3])
+	if (abs (r2) > 25.0)
+	    z = p[4]
+	else
+	    z = p[1] * exp (-r2) + p[4]
+end
+
+
+# CDGAUSS1D -- Compute the value a 1-D Gaussian profile on a constant
+# background and its derivatives.
+
+procedure cdgauss1d (x, nvars p, dp, np, z, der)
+
+real	x[ARB]		# variables, x[1] = position coordinate
+int	nvars		# the number of variables, not used
+real	p[ARB]		# p[1]=amplitude, p[2]=center, p[3]=sky p[4]=variance
+real	dp[ARB]		# parameter derivatives
+int	np		# number of parameters np=4
+real	z		# function value
+real	der[ARB]	# derivatives
+
+real	dx, r2
+
+begin
+	dx = x[1] - p[2]
+	if (p[3] == 0.)
+	    r2 = 36.0
+	else
+	    r2 = dx * dx / (2.0 * p[3])
+	if (abs (r2) > 25.0) {
+	    z = p[4]
+	    der[1] = 0.0
+	    der[2] = 0.0
+	    der[3] = 0.0
+	    der[4] = 1.0
+	} else {
+	    der[1] = exp (-r2)
+	    z = p[1] * der[1]
+	    der[2] = z * dx / p[3]
+	    der[3] = z * r2 / p[3]
+	    der[4] = 1.0
+	    z = z + p[4]
+	}
+end
+
+
+# GAUSSR -- Compute the value of a 2-D radially symmetric Gaussian profile
+# which is assumed to be sitting on a constant background.
+
+# Parameter Allocation:
+# 1	Amplitude
+# 2	X-center
+# 3	Y-center
+# 4	Variance
+# 5	Sky
+
+procedure gaussr (x, nvars, p, np, z)
+
+real	x[ARB]		# the input variables
+int	nvars		# the number of variables
+real	p[np]		# parameter vector
+int	np		# number of parameters
+real	z		# function return
+
+real	dx, dy, r2
+
+begin
+	dx = x[1] - p[2]
+	dy = x[2] - p[3]
+	if (p[4] == 0.)
+	    r2 = 36.0
+	else
+	    r2 = (dx * dx + dy * dy) / (2.0 * p[4])
+	if (abs (r2) > 25.0)
+	    z = p[5]
+	else
+	    z = p[1] * exp (- r2) + p[5]
+end
+
+
+# DGAUSSR -- Compute the value of a 2-D Gaussian profile and its derivatives
+# which assumed to be sitting on top of a constant background.
+
+procedure dgaussr (x, nvars, p, dp, np, z, der)
+
+real	x[ARB]		# the input variables
+int	nvars		# the number of variables
+real	p[np]		# parameter vector
+real	dp[np]		# dummy array of parameter increments
+int	np		# number of parameters
+real	z		# function return
+real	der[np]		# derivatives
+
+real	dx, dy, r2
+
+begin
+	dx = x[1] - p[2]
+	dy = x[2] - p[3]
+	if (p[4] == 0.)
+	    r2 = 36.0
+	else
+	    r2 = (dx * dx + dy * dy) / (2.0 * p[4])
+
+	if (abs (r2) > 25.0) {
+	    z = p[5]
+	    der[1] = 0.0
+	    der[2] = 0.0
+	    der[3] = 0.0
+	    der[4] = 0.0
+	    der[5] = 1.0
+	} else {
+	    der[1] = exp (-r2)
+	    z = p[1] * der[1]
+	    der[2] = z * dx / p[4] 
+	    der[3] = z * dy / p[4]
+	    der[4] = z * r2 / p[4]
+	    z = z + p[5]
+	    der[5] = 1.0
+	}
+end
+
+
+# ELGAUSS -- Compute the value of a 2-D elliptical Gaussian function which
+# is assumed to be sitting on top of a constant background.
+
+# Parameter Allocation:
+# 1	Amplitude
+# 2	X-center
+# 3	Y-center
+# 4	Variance-x
+# 5	Variance-y
+# 6	Theta-rotation
+# 7	Sky
+
+procedure elgauss (x, nvars, p, np, z)
+
+real	x[ARB]		# input variables, x[1] = x, x[2] = y
+int	nvars		# number of variables, not used
+real	p[np]		# parameter vector
+int	np		# number of parameters
+real	z		# function return
+
+real	dx, dy, crot, srot, xt, yt, r2
+
+begin
+	dx = x[1] - p[2]
+	dy = x[2] - p[3]
+	crot = cos (p[6])
+	srot = sin (p[6])
+	xt = (dx * crot + dy * srot)
+	yt = (-dx * srot + dy * crot)
+	if (p[4] == 0. || p[5] == 0.)
+	    r2 = 36.0
+	else
+	    r2 = (xt ** 2 / p[4] + yt ** 2 / p[5]) / 2.0
+	if (abs (r2) > 25.0)
+	    z = p[7]
+	else
+	    z = p[1] * exp (-r2) + p[7]
+end
+
+
+# DELGAUSS -- Compute the value of a 2-D elliptical Gaussian assumed to
+# sitting on top of a constant background and its derivatives.
+
+procedure delgauss (x, nvars, p, dp, np, z, der)
+
+real	x[ARB]		# input variables, x[1] = x, x[2] = y
+int	nvars		# number of variables, not used
+real	p[np]		# parameter vector
+real	dp[np]		# delta of parameters
+int	np		# number of parameters
+real	z		# function value
+real	der[np]		# function return
+
+real	crot, srot, crot2, srot2, sigx2, sigy2, a, b, c
+real	dx, dy, dx2, dy2, r2
+
+begin
+	crot = cos (p[6])
+	srot = sin (p[6])
+	crot2 = crot ** 2
+	srot2 = srot ** 2
+	sigx2 = p[4]
+	sigy2 = p[5]
+	if (sigx2 == 0. || sigy2 == 0.)
+	    r2 = 36.0
+	else {
+	    a = (crot2 / sigx2 + srot2 / sigy2)
+	    b = 2.0 * crot * srot * (1.0 / sigx2 - 1.0 /sigy2)
+	    c = (srot2 / sigx2 + crot2 / sigy2)
+
+	    dx = x[1] - p[2]
+	    dy = x[2] - p[3]
+	    dx2 = dx ** 2
+	    dy2 = dy ** 2
+	    r2 = 0.5 * (a * dx2 + b * dx * dy + c * dy2)
+	}
+
+	if (abs (r2) > 25.0) {
+	    z = p[7]
+	    der[1] = 0.0
+	    der[2] = 0.0
+	    der[3] = 0.0
+	    der[4] = 0.0
+	    der[5] = 0.0
+	    der[6] = 0.0
+	    der[7] = 1.0
+	} else {
+	    der[1] = exp (-r2)
+	    z = p[1] * der[1]
+	    der[2] = z * (2.0 * a * dx + b * dy)
+	    der[3] = z * (b * dx + 2.0 * c * dy)
+	    der[4] = z * (crot2 * dx2 + 2.0 * crot * srot * dx * dy +
+	        srot2 * dy2) / (2.0 * sigx2 * sigx2)
+	    der[5] = z * (srot2 * dx2 - 2.0 * crot * srot * dx * dy +
+	        crot2 * dy2) / (2.0 * sigy2 * sigy2)
+	    der[6] = z * (b * dx2 + 2.0 * (c - a) * dx * dy - b * dy2)  
+	    z = z + p[7]
+	    der[7] = 1.0
+	}
+end
+
+
+
+# GAUSS1D -- Compute the profile of a 1d Gaussian with a background value
+# of zero.
+
+procedure gauss1d (x, nvars, p, np, z)
+
+real	x[ARB]		# list of variables, x[1] = position coordinate
+int	nvars		# number of variables
+real	p[ARB]		# p[1]=amplitude p[2]=center p[3]=sigma
+int	np		# number of parameters == 3
+real	z		# function return
+
+real	r
+
+begin
+	if (p[3] == 0.)
+	    r = 6.0
+	else
+	    r = (x[1] - p[2]) / (p[3] * SQRTOF2)
+	if (abs (r) > 5.0)
+	    z = 0.0
+	else
+	    z = p[1] * exp (- r ** 2)
+end
+
+
+# DGAUSS1D -- Compute the function value and derivatives of a 1-D Gaussian
+# function with a background value of zero.
+
+procedure dgauss1d (x, nvars, p, dp, np, z, der)
+
+real	x[ARB]		# list of variables, x[1] = position coordinate
+int	nvars		# number of variables
+real	p[ARB]		# p[1]=amplitude, p[2]=center, p[3]=sigma
+real	dp[ARB]		# parameter derivatives
+int	np		# number of parameters
+real	z		# function value
+real	der[ARB]	# derivatives
+
+real	r
+
+begin
+	if (p[3] == 0.)
+	    r = 6.0
+	else
+	    r = (x[1] - p[2]) / (SQRTOF2 * p[3])
+	if (abs (r) > 5.0) {
+	    z = 0.0
+	    der[1] = 0.0
+	    der[2] = 0.0
+	    der[3] = 0.0
+	} else {
+	    der[1] = exp (- r ** 2)
+	    z = der[1] * p[1]
+	    der[2] = z * r  * SQRTOF2 / p[3]
+	    der[3] = der[2] * SQRTOF2 * r
+	}
+end
+
+
+# GAUSSKEW - Compute the value of a 1-D skewed Gaussian profile.
+# The background value is assumed to be zero.
+
+procedure gausskew (x, nvars, p, np, z)
+
+real	x[ARB]		# list of variables, x[1] = position coordinate
+int	nvars		# number of variables, not used
+real	p[ARB]		# p[1]=amplitude p[2]=center p[3]=variance p[4]=skew
+int	np		# number of parameters == 3
+real	z		# function return
+
+real	dx, r2, r3
+
+begin
+	dx = (x[1] - p[2])
+	if (p[3] == 0.)
+	    r2 = 36.0
+	else {
+	    r2 = dx ** 2 / (2.0 * p[3])
+	    r3 = r2 * dx / sqrt (2.0 * abs (p[3])) 
+	}
+	if (abs (r2) > 25.0)
+	    z = 0.0
+	else
+	    z = (1.0 + p[4] * r3) * p[1] * exp (-r2)
+end
+
+
+# DGAUSSKEW -- Compute the value of a 1-D skewed Gaussian and its derivatives. 
+# The background value is assumed to be zero.
+
+procedure dgausskew (x, nvars, p, dp, np, z, der)
+
+real	x[ARB]		# list of variables, x[1] = position coordinate
+int	nvars		# number of variables, not used
+real	p[ARB]		# p[1]=amplitude, p[2]=center, p[3]=variance, p[4]=skew
+real	dp[ARB]		# parameter derivatives
+int	np		# number of parameters
+real	z		# function value
+real	der[ARB]	# derivatives
+
+real	dx, d1, d2, d3, r, r2, r3, rint
+
+begin
+	dx = x[1] - p[2]
+	if (p[3] == 0.)
+	    r2 = 36.0
+	else
+	    r2 = dx ** 2 / (2.0 * p[3])
+	if (abs (r2) > 25.0) {
+	    z = 0.0
+	    der[1] = 0.0
+	    der[2] = 0.0
+	    der[3] = 0.0
+	    der[4] = 0.0
+	} else {
+	    r = dx / sqrt (2.0 * abs (p[3]))
+	    r3 = r2 * r
+	    d1 = exp (-r2)
+	    z = d1 * p[1]
+	    d2 = z * dx / p[3]
+	    d3 = z * r2 / p[3]
+	    rint = 1.0 + p[4] * r3
+	    der[1] = d1 * rint
+	    der[2] = d2 * (rint - 1.5 * p[4] * r)
+	    der[3] = d3 * (rint - 1.5 * p[4] * r)
+	    der[4] = z * r3
+	    z = z * rint
+	}
+end
diff --git a/noao/digiphot/apphot/aputil/appcache.x b/noao/digiphot/apphot/aputil/appcache.x
new file mode 100644
index 00000000..d1059583
--- /dev/null
+++ b/noao/digiphot/apphot/aputil/appcache.x
@@ -0,0 +1,83 @@
+include <imhdr.h>
+include <imset.h>
+
+# AP_MEMSTAT -- Figure out if there is  enough memory to cache the image
+# pixels. If it is necessary to request more memory and the memory is
+# avalilable return YES otherwise return NO.
+
+int procedure ap_memstat (cache, req_size, old_size)
+
+int	cache			#I cache memory ?
+int	req_size		#I the requested working set size in chars 
+int	old_size		#O the original working set size in chars 
+
+int	cur_size, max_size
+int	begmem()
+
+begin
+        # Find the default working set size.
+        cur_size = begmem (0, old_size, max_size)
+
+	# If cacheing is disabled return NO regardless of the working set size.
+	if (cache == NO)
+	    return (NO)
+
+	# If the requested working set size is less than the current working
+	# set size return YES.
+	if (req_size <= cur_size)
+	    return (YES)
+
+	# Reset the current working set size.
+	cur_size = begmem (req_size, old_size, max_size)
+	if (req_size <= cur_size) {
+	    return (YES)
+	} else {
+	    return (NO)
+	}
+end
+
+
+# AP_PCACHE -- Cache the image pixels im memory by resetting the  default image
+# buffer size. If req_size is INDEF the size of the image is used to determine
+# the size of the image i/o buffers.
+
+procedure ap_pcache (im, req_size, buf_size)
+
+pointer im                      #I the input image point
+int     req_size                #I the requested working set size in chars
+int	buf_size		#O the new image buffer size
+
+int     def_size, new_imbufsize
+int     sizeof(), imstati()
+
+begin
+	# Find the default buffer size.
+	def_size = imstati (im, IM_BUFSIZE)
+
+        # Return if the image is not 2-dimensional.
+        if (IM_NDIM(im) != 2) {
+	    buf_size = def_size
+            return
+	}
+
+        # Compute the new required image i/o buffer size in chars.
+        if (IS_INDEFI(req_size)) {
+            new_imbufsize = IM_LEN(im,1) * IM_LEN(im,2) *
+                sizeof (IM_PIXTYPE(im))
+        } else {
+            new_imbufsize = req_size
+        }
+
+	# If the default image i/o buffer size is already bigger than
+	# the requested size do nothing.
+	if (def_size >= new_imbufsize) {
+	    buf_size = def_size
+	    return
+	}
+
+        # Reset the image i/o buffer.
+        call imseti (im, IM_BUFSIZE, new_imbufsize)
+        call imseti (im, IM_BUFFRAC, 0)
+	buf_size = new_imbufsize
+        return 
+end
diff --git a/noao/digiphot/apphot/aputil/aprmwhite.x b/noao/digiphot/apphot/aputil/aprmwhite.x
new file mode 100644
index 00000000..071ea7ed
--- /dev/null
+++ b/noao/digiphot/apphot/aputil/aprmwhite.x
@@ -0,0 +1,22 @@
+include <ctype.h>
+
+# AP_RMWHITE -- Remove whitespace from a string.
+
+procedure ap_rmwhite (instr, outstr, maxch)
+
+char	instr[ARB]		# the input string
+char	outstr[ARB]		# the output string, may be the same as instr
+int	maxch			# maximum number of characters in outstr
+
+int	ip, op
+
+begin
+	op = 1
+	for (ip = 1; (instr[ip] != EOS) && (op <= maxch); ip = ip + 1) {
+	    if (IS_WHITE(instr[ip]))
+		next
+	    outstr[op] = instr[ip]
+	    op = op + 1
+	}
+	outstr[op] = EOS
+end
diff --git a/noao/digiphot/apphot/aputil/aptopt.x b/noao/digiphot/apphot/aputil/aptopt.x
new file mode 100644
index 00000000..0e5bc212
--- /dev/null
+++ b/noao/digiphot/apphot/aputil/aptopt.x
@@ -0,0 +1,232 @@
+include	<mach.h>
+include	<math.h>
+
+# APTOPT - One-dimensional centering routine using repeated convolutions to
+# locate image center.
+
+define	MAX_SEARCH	3	# Max initial search steps
+
+int procedure aptopt (data, npix, center, sigma, tol, maxiter, ortho)
+
+real	data[ARB]		# initial data
+int	npix			# number of pixels
+real	center			# initial guess at center
+real	sigma			# sigma of Gaussian
+real	tol			# gap tolerance for sigma
+int	maxiter			# maximum number of iterations
+int	ortho			# orthogonalize weighting vector
+
+int	i, iter
+pointer	sp, wgt
+real	newx, x[3], news, s[3], delx
+real	adotr(), apqzero()
+
+begin
+	if (sigma <= 0.0)
+	    return (-1)
+
+	# Allocate working space.
+	call smark (sp)
+	call salloc (wgt, npix, TY_REAL)
+
+	# Initialize.
+	x[1] = center
+	call mkt_prof_derv (Memr[wgt], npix, x[1], sigma, ortho)
+	s[1] = adotr (Memr[wgt], data, npix)
+	#if (abs (s[1]) <= EPSILONR) {
+	if (s[1] == 0.0) {
+	    center = x[1]
+	    call sfree (sp)
+	    return (0)
+	} else
+	    s[3] = s[1]
+
+	# Search for the correct interval.
+	for (i = 1; (s[3] * s[1] >= 0.0) && (i <= MAX_SEARCH); i = i + 1) {
+	    s[3] = s[1]
+	    x[3] = x[1]
+	    x[1] = x[3] + sign (sigma, s[3])
+	    call mkt_prof_derv (Memr[wgt], npix, x[1], sigma, ortho)
+	    s[1] = adotr (Memr[wgt], data, npix)
+	    #if (abs (s[1]) <= EPSILONR) {
+	    if (s[1] == 0.0) {
+		center = x[1]
+		call sfree (sp)
+		return (0)
+	    }
+	}
+
+	# Location not bracketed.
+	if (s[3] * s[1] > 0.0) {
+	    call sfree (sp)
+	    return (-1)
+	}
+
+	# Intialize the quadratic search.
+	delx = x[1] - x[3]
+	x[2] = x[3] - s[3] * delx / (s[1] - s[3])
+	call mkt_prof_derv (Memr[wgt], npix, x[2], sigma, ortho)
+	s[2] = adotr (Memr[wgt], data, npix)
+	#if (abs (s[2]) <= EPSILONR) {
+	if (s[2] == 0.0) {
+	    center = x[2]
+	    call sfree (sp)
+	    return (1)
+	}
+
+	# Search quadratically.
+	for (iter = 2; iter <= maxiter; iter = iter + 1)  {
+
+	    # Check for completion.
+	    #if (abs (s[2]) <= EPSILONR)
+	    if (s[2] == 0.0)
+		break
+	    if (abs (x[2] - x[1]) <= tol)
+		break
+	    if (abs (x[3] - x[2]) <= tol)
+		break
+
+	    # Compute new intermediate value.
+	    newx = x[1] + apqzero (x, s)
+	    call mkt_prof_derv (Memr[wgt], npix, newx, sigma, ortho)
+	    news = adotr (Memr[wgt], data, npix)
+
+	    if (s[1] * s[2] > 0.0) {
+		s[1] = s[2]
+		x[1] = x[2]
+		s[2] = news
+		x[2] = newx
+	    } else {
+		s[3] = s[2]
+		x[3] = x[2]
+		s[2] = news
+		x[2] = newx
+	    }
+	}
+
+	# Evaluate the center.
+	center = x[2]
+	call sfree (sp)
+	return (iter)
+end
+
+
+# AP_TPROFDER -- Procedure to estimate the approximating triangle function
+# and its derivatives.
+
+procedure ap_tprofder (data, der, npix, center, sigma, ampl)
+
+real	data[ARB]		# input data
+real	der[ARB]		# derivatives
+int	npix			# number of pixels
+real	center			# center of input Gaussian function
+real	sigma			# sigma of input Gaussian function
+real	ampl			# amplitude
+
+int	i
+real	x, xabs, width
+
+begin
+	width = sigma * 2.35
+	do i = 1, npix {
+	    x = (i - center) / width
+	    xabs = abs (x)
+	    if (xabs <= 1.0) {
+		data[i] = ampl * (1.0 - xabs)
+		der[i] = x * data[i]
+	    } else {
+		data[i] = 0.0
+		der[i] = 0.0
+	    }
+	}
+end
+
+
+# MKT_PROF_DERV - Make orthogonal profile derivative vector.
+
+procedure mkt_prof_derv (weight, npix, center, sigma, norm)
+
+real	weight[ARB]	# input weight
+int	npix		# number of pixels
+real	center		# center
+real	sigma		# center
+int	norm		# orthogonalise weight
+
+pointer	sp, der
+real	coef
+real	asumr(),  adotr()
+
+begin
+	call smark (sp)
+	call salloc (der, npix, TY_REAL)
+
+	# Fetch the weighting function and derivatives.
+	call ap_tprofder (Memr[der], weight, npix, center, sigma, 1.0)
+
+	if (norm == YES) {
+
+	    # Make orthogonal to level background.
+	    coef = -asumr (weight, npix) / npix
+	    call aaddkr (weight, coef, weight, npix)
+	    coef = -asumr (Memr[der], npix) / npix
+	    call aaddkr (Memr[der], coef, Memr[der], npix)
+
+	    # Make orthogonal to profile vector.
+	    coef = adotr (Memr[der], Memr[der], npix)
+	    if (coef <= 0.0)
+		coef = 1.0
+	    else
+	        coef = adotr (weight, Memr[der], npix) / coef
+	    call amulkr (Memr[der], coef, Memr[der], npix)
+	    call asubr (weight, Memr[der], weight, npix)
+
+	    # Normalize the final vector.
+	    coef = adotr (weight, weight, npix)
+	    if (coef <= 0.0)
+		coef = 1.0
+	    else
+	        coef = sqrt (1.0 / coef)
+	    call amulkr (weight, coef, weight, npix)
+	}
+
+	call sfree (sp)
+end
+
+define	QTOL	.125
+
+# APQZERO - Solve for the root of a quadratic function defined by three
+# points.
+
+real procedure apqzero (x, y)
+
+real	x[3]
+real	y[3]
+
+real	a, b, c, det, dx
+real	x2, x3, y2, y3
+
+begin
+	# Compute the determinant.
+	x2 = x[2] - x[1]
+	x3 = x[3] - x[1]
+	y2 = y[2] - y[1]
+	y3 = y[3] - y[1]
+	det = x2 * x3 * (x2 - x3)
+
+	# Compute the shift in x.
+	#if (abs (det) > 100.0 * EPSILONR) {
+	if (abs (det) > 0.0) {
+	    a = (x3 * y2 - x2 * y3) / det
+	    b = - (x3 * x3 * y2 - x2 * x2 * y3) / det
+	    c =  a * y[1] / (b * b)
+	    if (abs (c) > QTOL)
+		dx = (-b / (2.0 * a)) * (1.0 - sqrt (1.0 - 4.0 * c))
+	    else
+		dx = - (y[1] / b) * (1.0 + c)
+	    return (dx)
+	#} else if (abs (y3) > EPSILONR)
+	} else if (abs (y3) > 0.0)
+	    return (-y[1] * x3 / y3)
+	else
+	    return (0.0)
+end
diff --git a/noao/digiphot/apphot/aputil/apvectors.x b/noao/digiphot/apphot/aputil/apvectors.x
new file mode 100644
index 00000000..7c9dbcfd
--- /dev/null
+++ b/noao/digiphot/apphot/aputil/apvectors.x
@@ -0,0 +1,515 @@
+
+# AP_ABOXR -- Vector boxcar smooth. The input vector is convolved with a
+# uniform kernel of length knpix. Boundary extension is assumed to have
+# been performed on the input array before entering the routine.
+
+procedure ap_aboxr (in, out, npix, knpix)
+
+real	in[npix+knpix-1]	# input array with boundary exntension
+real	out[npix]		# output array
+int	npix			# number of pixels
+int	knpix			# length of the kernel
+
+int	i
+real	sum
+
+begin
+	sum = 0.0
+	do i = 1, knpix - 1
+	    sum = sum + in[i]
+
+	do i = 1, npix {
+	    sum = sum + in[i+knpix-1] 
+	    out[i] = sum / knpix
+	    sum = sum - in[i]
+	}
+
+end
+
+
+# AP_SBOXR -- Boxcar smooth for a vector that has not been boundary
+# extended.
+
+procedure ap_sboxr (in, out, npix, nsmooth)
+
+real	in[npix]		# input array 
+real	out[npix]		# output array
+int	npix			# number of pixels
+int	nsmooth			# half width of smoothing box
+
+int	i, j, ib, ie, ns
+real	sum
+
+begin
+	ns = 2 * nsmooth + 1
+	do i = 1, npix {
+	    ib = max (i - nsmooth, 1)
+	    ie = min (i + nsmooth, npix)
+	    sum = 0.0
+	    do j = ib, ie
+	        sum = sum + in[j]
+	    out[i] = sum / ns
+	}
+end
+
+
+# AP_ALIMR -- Compute the maximum and minimum data values and indices of a
+# 1D array.
+
+procedure ap_alimr (data, npts, mindat, maxdat, imin, imax)
+
+real	data[npts]	# data array
+int	npts		# number of points
+real	mindat, maxdat	# min and max data value
+int	imin, imax	# indices of min and max data values
+
+int	i
+
+begin
+	imin = 1
+	imax = 1
+	mindat = data[1]
+	maxdat = data[1]
+
+	do i = 2, npts {
+	    if (data[i] > maxdat) {
+		imax = i
+		maxdat = data[i]
+	    }
+	    if (data[i] < mindat) {
+		imin = i
+		mindat = data[i]
+	    }
+	}
+end
+
+
+# AP_IALIMR -- Compute the maximum and minimum data values of a 1D indexed
+# array
+
+procedure ap_ialimr (data, index, npts, mindat, maxdat)
+
+real	data[npts]	# data array
+int	index[npts]	# index array
+int	npts		# number of points
+real	mindat, maxdat	# min and max data value
+
+int	i
+
+begin
+	mindat = data[index[1]]
+	maxdat = data[index[1]]
+	do i = 2, npts {
+	    if (data[index[i]] > maxdat)
+		maxdat = data[index[i]]
+	    if (data[index[i]] < mindat)
+		mindat = data[index[i]]
+	}
+end
+
+
+# AP_ASUMR - Compute the sum of an index sorted array
+
+real procedure ap_asumr (data, index, npts)
+
+real	data[npts]	# data array
+int	index[npts]	# index array
+int	npts		# number of points
+
+double	sum
+int	i
+
+begin
+	sum = 0.0d0
+	do i = 1, npts
+	    sum = sum + data[index[i]]
+	return (real (sum))
+end
+
+
+# AP_AMAXEL -- Find the maximum value and its index of a 1D array.
+
+procedure ap_amaxel (a, npts, maxdat, imax)
+
+real	a[ARB]		# the data array
+int	npts		# number of points
+real	maxdat		# maximum value
+int	imax		# imdex of max value
+
+int	i
+
+begin
+	maxdat = a[1]
+	imax = 1
+	do i = 2, npts {
+	    if (a[i] > maxdat) {
+		maxdat = a[i]
+		imax = i
+	    }
+	}
+end
+
+
+# AHGMR -- Accumulate the histogram of the input vector.  The output vector
+# hgm (the histogram) should be cleared prior to the first call. The procedure
+# returns the number of data values it could not include in the histogram.
+
+int procedure aphgmr (data, wgt, npix, hgm, nbins, z1, z2)
+
+real 	data[ARB]		# data vector
+real	wgt[ARB]		# weights vector
+int	npix			# number of pixels
+real	hgm[ARB]		# output histogram
+int	nbins			# number of bins in histogram
+real	z1, z2			# greyscale values of first and last bins
+
+real	dz
+int	bin, i, nreject
+
+begin
+	if (nbins < 2)
+	    return (0)
+
+	nreject = 0
+	dz = real (nbins - 1) / real (z2 - z1)
+	do i = 1, npix {
+	    if (data[i] < z1 || data[i] > z2) {
+		nreject = nreject + 1
+		wgt[i] = 0.0
+		next
+	    }
+	    bin = int ((data[i] - z1) * dz) + 1
+	    hgm[bin] = hgm[bin] + 1.0
+	}
+
+	return (nreject)
+end
+
+
+# APHIGMR -- Accumulate the histogram of the input vector.  The output vector
+# hgm (the histogram) should be cleared prior to the first call. The procedure
+# returns the number of data values it could not include in the histogram.
+
+int procedure aphigmr (data, wgt, index, npix, hgm, nbins, z1, z2)
+
+real 	data[ARB]		# data vector
+real	wgt[ARB]		# weights vector
+int	index[ARB]		# index vector
+int	npix			# number of pixels
+real	hgm[ARB]		# output histogram
+int	nbins			# number of bins in histogram
+real	z1, z2			# greyscale values of first and last bins
+
+real	dz
+int	bin, i, nreject
+
+begin
+	if (nbins < 2)
+	    return (0)
+
+	nreject = 0
+	dz = real (nbins - 1) / real (z2 - z1)
+	do i = 1, npix {
+	    if (data[index[i]] < z1 || data[index[i]] > z2) {
+		nreject = nreject + 1
+		wgt[index[i]] = 0.0
+		next
+	    }
+	    bin = int ((data[index[i]] - z1) * dz) + 1
+	    hgm[bin] = hgm[bin] + 1.0
+	}
+
+	return (nreject)
+end
+
+
+# AP_IJTOR -- Compute radius values given the center coordinates, the line
+# number in a the subraster and the length of the subraster x axis.
+
+procedure ap_ijtor (r, nr, line, xc, yc)
+
+real	r[nr]		# array of output r values
+int	nr		# length of r array
+int	line		# line number
+real	xc, yc		# subraster center
+
+int	i
+real	temp
+
+begin
+	temp = (line - yc ) ** 2
+	do i = 1, nr
+	    r[i] = sqrt ((i - xc) ** 2 + temp)
+end
+
+
+# AP_IJTOR2 -- Compute radius values given the center coordinates and the size
+# of the subraster.
+
+procedure ap_ijtor2 (r, nx, ny, xc, yc)
+
+real	r[nx,ARB]	# array of output r values
+int	nx		# x dimension of output array
+int	ny		# Y dimension of output array
+real	xc, yc		# subraster center
+
+int	i, j
+real	temp
+
+begin
+	do j = 1, ny {
+	    temp = (j - yc) ** 2
+	    do i = 1, nx
+	        r[i,j] = sqrt ((i - xc) ** 2 + temp)
+	}
+end
+
+
+# AP_2DALIMR -- Compute min and max values of a 2D array along with
+# the indices of the minimum and maximum pixel.
+
+procedure ap_2dalimr (data, nx, ny, mindat, maxdat, imin, jmin, imax, jmax)
+
+real	data[nx, ny]	# data
+int	nx, ny		# array dimensions
+real	mindat, maxdat	# min, max data values
+int	imin, jmin	# indices of min element
+int	imax, jmax	# indices of max element
+
+int	i, j
+
+begin
+	imin = 1
+	jmin = 1
+	imax = 1
+	jmax = 1
+	mindat = data[1,1]
+	maxdat = data[1,1]
+
+	do j = 2, ny {
+	    do i = 1, nx {
+		if (data[i,j] < mindat) {
+		    imin = i
+		    jmin = j
+		    mindat = data[i,j]
+		} else if (data[i,j] > maxdat) {
+		    imax = i
+		    jmax = j
+		    maxdat = data[i,j]
+		}
+	    }
+	}
+end
+
+
+define	LOGPTR		20			# log2(maxpts) (1e6)
+
+# APQSORT -- Vector Quicksort. In this version the index array is
+# sorted.
+
+procedure apqsort (data, a, b, npix)
+
+real	data[ARB]		# data array
+int	a[ARB], b[ARB]		# index array
+int	npix			# number of pixels
+
+int	i, j, lv[LOGPTR], p, uv[LOGPTR], temp
+real	pivot
+
+begin
+	# Initialize the indices for an inplace sort.
+	do i = 1, npix
+	    a[i] = i
+	call amovi (a, b, npix)
+
+	p = 1
+	lv[1] = 1
+	uv[1] = npix
+	while (p > 0) {
+
+	    # If only one elem in subset pop stack otherwise pivot line.
+	    if (lv[p] >= uv[p])
+		p = p - 1
+	    else {
+		i = lv[p] - 1
+		j = uv[p]
+		pivot = data[b[j]]
+
+		while (i < j) {
+		    for (i=i+1;  data[b[i]] < pivot;  i=i+1)
+			;
+		    for (j=j-1;  j > i;  j=j-1)
+			if (data[b[j]] <= pivot)
+			    break
+		    if (i < j) {		# out of order pair
+			temp = b[j]		# interchange elements
+			b[j] = b[i]
+			b[i] = temp
+		    }
+		}
+
+		j = uv[p]			# move pivot to position i
+		temp = b[j]			# interchange elements
+		b[j] = b[i]
+		b[i] = temp
+
+		if (i-lv[p] < uv[p] - i) {	# stack so shorter done first
+		    lv[p+1] = lv[p]
+		    uv[p+1] = i - 1
+		    lv[p] = i + 1
+		} else {
+		    lv[p+1] = i + 1
+		    uv[p+1] = uv[p]
+		    uv[p] = i - 1
+		}
+
+		p = p + 1			# push onto stack
+	    }
+	}
+end
+
+
+
+# APRECIPROCAL -- Compute the reciprocal of the absolute value of a vector.
+
+procedure apreciprocal (a, b, npts, value)
+
+real	a[ARB]		# the input vector
+real	b[ARB]		# the output vector
+int	npts		# the number of data points
+real	value		# the value to be assigned to b[i] if a[i] = 0
+
+int	i
+
+begin
+	do i = 1, npts {
+	    if (a[i] > 0.0)
+		b[i] = 1.0 / a[i]
+	    else if (a[i] < 0.0)
+		b[i] = - 1.0 / a[i]
+	    else
+		b[i] = value
+	}
+end
+
+
+# AP_WLIMR -- Set the weights of all data points outside a given minimum and
+# maximum values to zero. Compute the minimum and maximum values and their
+# indices of the remaining data.
+
+procedure ap_wlimr (pix, w, npts, datamin, datamax, dmin, dmax, imin, imax)
+
+real	pix[ARB]		# input pixel array
+real	w[ARB]			# weight array
+int	npts			# number of points
+real	datamin			# minimum good data point
+real	datamax			# maximum good data point
+real	dmin			# output data minimum
+real	dmax			# output data maximum
+int	imin			# index of the data minimum
+int	imax			# index of the data maximum
+
+int	i
+real	value
+
+begin
+	dmin = datamax
+	dmax = datamin
+	imin = 1
+	imax = 1
+
+	do i = 1, npts {
+	    value = pix[i]
+	    if ((value < datamin) || (value > datamax)) {
+		w[i] = 0.0
+		next
+	    }
+	    if (value  < dmin) {
+		dmin = value
+		imin = i
+	    } else if (value  > dmax) {
+		dmax = value
+		imax = i
+	    }
+	}
+end
+
+
+# APWSSQR -- Compute the weighted sum of the squares of a vector.
+
+real procedure apwssqr (a, wgt, npts)
+
+real	a[ARB]		# data array
+real	wgt[ARB]	# array of weights
+int	npts		# number of points
+
+int	i
+real	sum
+
+begin
+	sum = 0.0
+	do i = 1, npts
+	    sum = sum + wgt[i] * a[i] * a[i]
+	return (sum)
+end
+
+
+# AP_XYTOR -- Change the single integer coord of the sky pixels to a radial
+# distance value. The integer coordinate is equal to coord = (i - xc + 1) +
+# blklen * (j - yc).
+
+procedure ap_xytor (coords, index, r, nskypix, xc, yc, blklen)
+
+int	coords[ARB]		# coordinate array
+int	index[ARB]		# the index array
+real	r[ARB]			# radial coordinates
+int	nskypix			# number of sky pixels
+real	xc, yc			# center of sky subraster
+int	blklen			# x dimension of sky subraster
+
+int	i
+real	x, y
+
+begin
+	do i = 1, nskypix {
+	    x = real (mod (coords[index[i]], blklen))
+	    if (x == 0)
+		x = real (blklen)
+	    y = (coords[index[i]] - x) / blklen + 1 
+	    r[i] = sqrt ((x - xc) ** 2 + (y - yc) ** 2)
+	}
+end
+
+
+# AP_W1SUR -- Linearly combine two vectors where the weight for the first
+# vectors is 1.0 and is k2 for the second vector
+
+procedure ap_w1sur (a, b, c, npts, k2)
+
+real	a[ARB]		# the first input vector
+real	b[ARB]		# the second input vector
+real	c[ARB]		# the output vector
+int	npts		# number of points
+real	k2		# the weigting factor for the second vector
+
+int	i
+
+begin
+	do i = 1, npts
+	    c[i] = a[i] + k2 * b[i]
+end
+
+
+# AP_INDEX -- Define an index array.
+
+procedure ap_index (index, npix)
+
+int	index[ARB]		# the index array
+int	npix			# the number of pixels
+
+int	i
+
+begin
+	do i = 1, npix
+	    index[i] = i
+end
diff --git a/noao/digiphot/apphot/aputil/mkpkg b/noao/digiphot/apphot/aputil/mkpkg
new file mode 100644
index 00000000..eefeed9d
--- /dev/null
+++ b/noao/digiphot/apphot/aputil/mkpkg
@@ -0,0 +1,25 @@
+# Miscellaneous Routines used by the APPHOT Package
+
+$checkout libpkg.a ".."
+$update libpkg.a
+$checkin libpkg.a ".."
+$exit
+
+libpkg.a:
+	apbsmooth.x
+	apclip.x
+	apdate.x		<time.h>
+	apdiverr.x
+	apfnames.x
+	apgscur.x		<gset.h>		<fset.h>
+	apgtools.x		<pkg/gtools.h>		<gset.h>
+	aplucy.x
+	apnlfuncs.x		<mach.h>		<math.h>
+	apmapr.x
+	apmeds.x
+	apmoments.x
+	appcache.x		<imhdr.h>		<imset.h>
+	aprmwhite.x		<ctype.h>
+	aptopt.x		<math.h> <mach.h>
+	apvectors.x
+	;
diff --git a/noao/digiphot/apphot/center.par b/noao/digiphot/apphot/center.par
new file mode 100644
index 00000000..3dbe8ad8
--- /dev/null
+++ b/noao/digiphot/apphot/center.par
@@ -0,0 +1,21 @@
+# CENTER
+
+image,f,a,,,,"Input image(s)"
+coords,f,h,"",,,"Input coordinate list(s) (default: image.coo.?)"
+output,f,h,"default",,,"Output center file(s) (default: image.ctr.?)"
+plotfile,s,h,"",,,"Output plot metacode file"
+datapars,pset,h,"",,,"Data dependent parameters"
+centerpars,pset,h,"",,,"Centering parameters"
+interactive,b,h,yes,,,"Interactive mode ?"
+radplots,b,h,no,,,"Plot the radial profiles in interactive mode ?"
+icommands,*imcur,h,"",,,"Image cursor: [x y wcs] key [cmd]"
+gcommands,*gcur,h,"",,,"Graphics cursor: [x y wcs] key [cmd]"
+wcsin,s,h,)_.wcsin,,,"The input coordinate system (logical,tv,physical,world)"
+wcsout,s,h,)_.wcsout,,,"The output coordinate system (logical,tv,physical)"
+cache,b,h,)_.cache,,,"Cache the input image pixels in memory ?"
+verify,b,h,)_.verify,,,"Verify critical parameters in non-interactive mode ?"
+update,b,h,)_.update,,,"Update critical parameters in non-interactive mode ?"
+verbose,b,h,)_.verbose,,,"Print messages in non-interactive mode ?"
+graphics,s,h,)_.graphics,,,"Graphics device"
+display,s,h,)_.display,,,"Display device"
+mode,s,h,'ql'
diff --git a/noao/digiphot/apphot/center/apbcenter.x b/noao/digiphot/apphot/center/apbcenter.x
new file mode 100644
index 00000000..9a607ee3
--- /dev/null
+++ b/noao/digiphot/apphot/center/apbcenter.x
@@ -0,0 +1,96 @@
+include <fset.h>
+include "../lib/apphot.h"
+include "../lib/display.h"
+
+# APBCENTER -- Procedure to determine accurate centers for a list of objects
+# in batch mode using a simple text file list.
+
+procedure apbcenter (ap, im, cl, out, id, ld, mgd, gid, interactive)
+
+pointer ap			# pointer to the apphot structure
+pointer	im			# pointer to the IRAF image
+int	cl			# the coordinate file descriptor
+int	out			# output file descriptor
+int	id			# output file sequence number
+int	ld			# the coordinate file list number
+pointer	mgd			# pointer to the metacode file stream
+pointer	gid			# pointer to the image display stream
+int	interactive		# mode of use
+
+int	stdin, ier, ild
+pointer	sp, str
+real	wx, wy
+int	apfitcenter(), fscan(), nscan(), strncmp(), apstati()
+
+begin
+	call smark (sp)
+	call salloc (str, SZ_FNAME, TY_CHAR)
+	call fstats (cl, F_FILENAME, Memc[str], SZ_FNAME)
+
+	# Initialize.
+	ild = ld
+
+        # Print query.
+	if (strncmp ("STDIN", Memc[str], 5) == 0) {
+	    stdin = YES
+	    call printf ("Type object x and y coordinates (^D or ^Z to end): ")
+	    call flush (STDOUT)
+	} else
+	    stdin = NO
+
+	# Loop over the coordinate file.
+	while (fscan (cl) != EOF) {
+
+	    # Get and store the coordinates.
+	    call gargr (wx)
+	    call gargr (wy)
+	    if (nscan () != 2) {
+	        if (stdin == YES) {
+		    call printf (
+		        "Type object x and y coordinates (^D or ^Z to end): ")
+		    call flush (STDOUT)
+	        } 
+		next
+	    }
+
+	    # Transform the input coordinates.
+	    switch (apstati(ap,WCSIN)) {
+	    case WCS_WORLD, WCS_PHYSICAL:
+		call ap_itol (ap, wx, wy, wx, wy, 1)
+	    case WCS_TV:
+		call ap_vtol (im, wx, wy, wx, wy, 1)
+	    default:
+		;
+	    }
+
+	    call apsetr (ap, CWX, wx)
+	    call apsetr (ap, CWY, wy)
+
+	    # Fit the center.
+	    ier = apfitcenter (ap, im, wx, wy)
+
+	    # Print and/or plot the results.
+	    if (interactive == YES) {
+		call ap_qcenter (ap, ier)
+		if (gid != NULL)
+		    call apmark (ap, gid, apstati (ap, MKCENTER), NO, NO)
+	    }
+	    call ap_cplot (ap, id, mgd, YES)
+	    if (id == 1)
+	        call ap_param (ap, out, "center")
+	    call ap_pcenter (ap, out, id, ild, ier)
+
+	    # Setup for the next object.
+	    id = id + 1
+	    ild = ild + 1
+	    call apsetr (ap, WX, wx)
+	    call apsetr (ap, WY, wy)
+	    if (stdin == YES) {
+		call printf (
+		    "Type object x and y coordinates (^D or ^Z to end): ")
+		call flush (STDOUT)
+	    } 
+	}
+
+	call sfree (sp)
+end
diff --git a/noao/digiphot/apphot/center/apcconfirm.x b/noao/digiphot/apphot/center/apcconfirm.x
new file mode 100644
index 00000000..6c570bd4
--- /dev/null
+++ b/noao/digiphot/apphot/center/apcconfirm.x
@@ -0,0 +1,75 @@
+include "../lib/apphot.h"
+include "../lib/noise.h"
+include "../lib/center.h"
+
+# AP_CCONFIRM -- Procedure to confirm the critical center parameters.
+
+procedure ap_cconfirm (ap, out, stid)
+
+pointer	ap		# pointer to the apphot structure
+int	out		# output file descriptor
+int	stid		# output file sequence number
+
+pointer	sp, str
+real	fwhmpsf, capert, skysigma, datamin, datamax
+int	apstati()
+real	apstatr(), ap_vfwhmpsf(), ap_vcapert(), ap_vsigma()
+real	ap_vdatamin(), ap_vdatamax()
+
+begin
+	call smark (sp)
+	call salloc (str, SZ_FNAME, TY_CHAR)
+
+	call printf ("\n")
+
+	# Confirm the centering algorithm.
+	call ap_vcstring (ap, Memc[str], SZ_FNAME)
+
+	if (apstati (ap, CENTERFUNCTION) != AP_NONE) {
+
+	    # Confirm the fwhmpsf.
+	    if (apstati (ap, CENTERFUNCTION) != AP_CENTROID1D) {
+		fwhmpsf = ap_vfwhmpsf (ap)
+	    } else
+	    	fwhmpsf = apstatr (ap, FWHMPSF)
+
+	    # Confirm the centering box.
+	    capert = 2.0 * ap_vcapert (ap)
+
+	    # Confirm the sky sigma parameter.
+	    skysigma = ap_vsigma (ap)
+
+	} else {
+
+	    fwhmpsf = apstatr (ap, FWHMPSF)
+	    capert = 2.0 * apstatr (ap, CAPERT)
+	    skysigma = apstatr (ap, SKYSIGMA)
+
+	}
+
+	# Confirm the sky sigma parameter.
+
+	# Confirm the minimum and maximum good data values.
+	datamin = ap_vdatamin (ap)
+	datamax = ap_vdatamax (ap)
+
+	call printf ("\n")
+
+	# Update the database file.
+	if (out != NULL && stid > 1) {
+	    call ap_sparam (out, KY_CSTRING, Memc[str], UN_CALGORITHM,
+		"centering algorithm")
+	    call ap_rparam (out, KY_FWHMPSF, fwhmpsf, UN_ASCALEUNIT,
+	        "full width half maximum of the psf")
+	    call ap_rparam (out, KY_CAPERT, capert, UN_CSCALEUNIT,
+	        "centering box width")
+	    call ap_rparam (out, KY_SKYSIGMA, skysigma, UN_NCOUNTS,
+	        "standard deviation of 1 sky pixel")
+	    call ap_rparam (out, KY_DATAMIN, datamin, UN_ACOUNTS,
+	        "minimum good data value")
+	    call ap_rparam (out, KY_DATAMAX, datamax, UN_ACOUNTS,
+	        "maximum good data value")
+	}
+
+	call sfree (sp)
+end
diff --git a/noao/digiphot/apphot/center/apcencolon.x b/noao/digiphot/apphot/center/apcencolon.x
new file mode 100644
index 00000000..9f2f40f8
--- /dev/null
+++ b/noao/digiphot/apphot/center/apcencolon.x
@@ -0,0 +1,329 @@
+include "../lib/apphot.h"
+include "../lib/display.h"
+include "../lib/noise.h"
+include "../lib/center.h"
+
+# APCENTERCOLON -- Process colon commands from the centering task.
+
+procedure apcentercolon (ap, im, cl, out, stid, ltid, cmdstr, newimage,
+	newbuf, newfit)
+
+pointer	ap		# pointer to the apphot structure
+pointer	im		# pointer to the iraf image
+int	cl		# coordinate file descriptor
+int	out		# output file descriptor
+int	stid		# output file sequence number
+int	ltid		# input list sequence number
+char	cmdstr[ARB]	# command string
+int	newimage	# new image ?
+int	newbuf		# new center buffer ?
+int	newfit		# new center fit ?
+
+int	junk
+pointer	sp, incmd, outcmd
+int	strdic()
+
+begin
+	# Allocate working space.
+	call smark (sp)
+	call salloc (incmd, SZ_LINE, TY_CHAR)
+	call salloc (outcmd, SZ_LINE, TY_CHAR)
+
+	# Get the command.
+	call sscan (cmdstr)
+	call gargwrd (Memc[incmd], SZ_LINE)
+	if (Memc[incmd] == EOS) {
+	    call sfree (sp)
+	    return
+	}
+
+	# Process the command.
+	if (strdic (Memc[incmd], Memc[outcmd], SZ_LINE, CCMDS) != 0)
+	    call ap_ccolon (ap, out, stid, cmdstr, newbuf, newfit)
+	else if (strdic (Memc[incmd], Memc[outcmd], SZ_LINE, APCMDS) != 0)
+	    call ap_apcolon (ap, im, cl, out, stid, ltid, cmdstr, newimage,
+	        newbuf, newfit, junk, junk, junk, junk)
+	else if (strdic (Memc[incmd], Memc[outcmd], SZ_LINE, NCMDS) != 0)
+	    call ap_nscolon (ap, im, out, stid, cmdstr, newbuf, newfit,
+		junk, junk, junk, junk)
+	else
+	    call ap_cimcolon (ap, cmdstr) 
+
+	call sfree (sp)
+end
+
+
+# AP_CCOLON -- Process colon commands affecting the centering parameters.
+
+procedure ap_ccolon (ap, out, stid, cmdstr, newbuf, newfit)
+
+pointer	ap		# pointer to the apphot structure
+int	out		# output file descriptor
+int	stid		# output list id number
+char	cmdstr		# command string
+int	newbuf		# new sky buffer
+int	newfit		# new sky fit
+
+bool	bval
+int	ival, ncmd, stat
+pointer	sp, cmd, str
+real	rval
+
+bool	itob()
+int	nscan(), strdic(), btoi(), apstati()
+real	apstatr()
+
+begin
+	call smark (sp)
+	call salloc (cmd, SZ_LINE, TY_CHAR)
+	call salloc (str, SZ_FNAME, TY_CHAR)
+
+	# Get the command.
+	call sscan (cmdstr)
+	call gargwrd (Memc[cmd], SZ_LINE)
+	if (Memc[cmd] == EOS) {
+	    call sfree (sp)
+	    return
+	}
+
+	# Process the command.
+	ncmd = strdic (Memc[cmd], Memc[cmd], SZ_LINE, CCMDS)
+	switch (ncmd) {
+
+	case CCMD_CBOXWIDTH:
+	    call gargr (rval)
+	    if (nscan() == 1) {
+		call printf ("%s = %g %s\n")
+		    call pargstr (KY_CAPERT)
+		    call pargr (2.0 * apstatr (ap, CAPERT))
+		    call pargstr (UN_CSCALEUNIT)
+	    } else {
+		call apsetr (ap, CAPERT, (rval / 2.0))
+		if (stid > 1)
+		    call ap_rparam (out, KY_CAPERT, rval, UN_CSCALEUNIT,
+			"centering subraster width")
+		newbuf = YES
+		newfit = YES
+	    }
+
+	case CCMD_CALGORITHM:
+	    call gargwrd (Memc[cmd], SZ_LINE)
+	    if (Memc[cmd] == EOS) {
+		call apstats (ap, CSTRING, Memc[str], SZ_FNAME)
+	        call printf ("%s = %s %s\n")
+		    call pargstr (KY_CSTRING)
+		    call pargstr (Memc[str])
+		    call pargstr (UN_CALGORITHM)
+	    } else {
+		stat = strdic (Memc[cmd], Memc[cmd], SZ_LINE, CFUNCS)
+		if (stat > 0) {
+		    call apseti (ap, CENTERFUNCTION, stat)
+		    call apsets (ap, CSTRING, Memc[cmd])
+		    if (stid > 1)
+		        call ap_sparam (out, KY_CSTRING, Memc[cmd],
+			    UN_CALGORITHM, "centering algorihtm")
+		    newbuf = YES
+		    newfit = YES
+		}
+	    }
+
+	case CCMD_CTHRESHOLD:
+	    call gargr (rval)
+	    if (nscan() == 1) {
+		call printf ("%s = %g %s\n")
+		    call pargstr (KY_CTHRESHOLD)
+		    call pargr (apstatr (ap, CTHRESHOLD))
+		    call pargstr (UN_CSIGMA)
+	    } else {
+		call apsetr (ap, CTHRESHOLD, rval)
+		if (stid > 1)
+		    call ap_rparam (out, KY_CTHRESHOLD, rval, UN_CSIGMA,
+			"threshold for centering")
+		newbuf = YES
+		newfit = YES
+	    }
+
+	case CCMD_MAXSHIFT:
+	    call gargr (rval)
+	    if (nscan() == 1) {
+		call printf ("%s = %g %s\n")
+		    call pargstr (KY_MAXSHIFT)
+		    call pargr (apstatr (ap, MAXSHIFT))
+		    call pargstr (UN_CSCALEUNIT)
+	    } else {
+		call apsetr (ap, MAXSHIFT, rval)
+		if (stid > 1)
+		    call ap_rparam (out, KY_MAXSHIFT, rval, UN_CSCALEUNIT,
+			"maximum shift")
+		newfit = YES
+	    }
+
+	case CCMD_MINSNRATIO:
+	    call gargr (rval)
+	    if (nscan() == 1) {
+		call printf ("%s = %g\n")
+		    call pargstr (KY_MINSNRATIO)
+		    call pargr (apstatr (ap, MINSNRATIO))
+	    } else {
+		call apsetr (ap, MINSNRATIO, rval)
+		if (stid > 1)
+		    call ap_rparam (out, KY_MINSNRATIO, rval,
+		        UN_CNUMBER, "minimum signal-to-noise ratio")
+		newfit = YES
+	    }
+
+	case CCMD_CMAXITER:
+	    call gargi (ival)
+	    if (nscan () == 1) {
+		call printf ("%s = %d\n")
+		    call pargstr (KY_CMAXITER)
+		    call pargi (apstati (ap, CMAXITER))
+	    } else {
+		call apseti (ap, CMAXITER, ival)
+		if (stid > 1)
+		    call ap_iparam (out, KY_CMAXITER, ival, UN_CNUMBER,
+			"maximum number of iterations")
+		newfit = YES
+	    }
+
+	case CCMD_CLEAN:
+	    call gargb (bval)
+	    if (nscan () == 1) {
+		call printf ("%s = %b\n")
+		    call pargstr (KY_CLEAN)
+		    call pargb (itob (apstati (ap, CLEAN)))
+	    } else {
+		call apseti (ap, CLEAN, btoi (bval))
+		if (stid > 1)
+		    call ap_bparam (out, KY_CLEAN, bval, UN_CSCALEUNIT,
+			"apply clean algorithm before centering")
+		newbuf = YES
+		newfit = YES
+	    }
+
+	case  CCMD_RCLEAN:
+	    call gargr (rval)
+	    if (nscan() == 1) {
+		call printf ("%s = %g %s\n")
+		    call pargstr (KY_RCLEAN)
+		    call pargr (apstatr (ap, RCLEAN))
+		    call pargstr (UN_CSCALEUNIT)
+	    } else {
+		call apsetr (ap, RCLEAN, rval)
+		if (stid > 1)
+		    call ap_rparam (out, KY_RCLEAN, rval, UN_CSCALEUNIT,
+			"cleaning radius")
+		newbuf = YES
+		newfit = YES
+	    }
+
+	case CCMD_RCLIP:
+	    call gargr (rval)
+	    if (nscan() == 1) {
+		call printf ("%s = %g %s\n")
+		    call pargstr (KY_RCLIP)
+		    call pargr (apstatr (ap, RCLIP))
+		    call pargstr (UN_CSCALEUNIT)
+	    } else {
+		call apsetr (ap, RCLIP, rval)
+		if (stid > 1)
+		    call ap_rparam (out, KY_RCLIP, rval, UN_CSCALEUNIT,
+			"clipping radius")
+		newbuf = YES
+		newfit = YES
+	    }
+
+	case CCMD_KCLEAN:
+	    call gargr (rval)
+	    if (nscan() == 1) {
+		call printf ("%s = %g %s\n")
+		    call pargstr (KY_SIGMACLEAN)
+		    call pargr (apstatr (ap, SIGMACLEAN))
+		    call pargstr (UN_CSIGMA)
+	    } else {
+		call apsetr (ap, SIGMACLEAN, rval)
+		if (stid > 1)
+		    call ap_rparam (out, KY_SIGMACLEAN, rval,
+		        UN_CSIGMA, "k-sigma clean rejection criterion")
+		newbuf = YES
+		newfit = YES
+	    }
+
+	case CCMD_MKCENTER:
+	    call gargb (bval)
+	    if (nscan() == 1) {
+		call printf ("%s = %b\n")
+		    call pargstr (KY_MKCENTER)
+		    call pargb (itob (apstati (ap, MKCENTER)))
+	    } else
+		call apseti (ap, MKCENTER, btoi (bval))
+
+	default:
+	    call printf ("Unknown or ambiguous colon command\7\n")
+	}
+
+	call sfree (sp)
+end
+
+
+# AP_CIMCOLON --  Process colon commands for the center task that do
+# not affect the centering parameters
+
+procedure ap_cimcolon (ap, cmdstr)
+
+pointer	ap			# pointer to the apphot structure
+char	cmdstr[ARB]		# command string
+
+bool	bval
+int	ncmd
+pointer	sp, cmd
+bool	itob()
+int	strdic(), nscan(), apstati(), btoi()
+
+begin
+	call smark (sp)
+	call salloc (cmd, SZ_LINE, TY_CHAR)
+
+	# Get the command.
+	call sscan (cmdstr)
+	call gargwrd (Memc[cmd], SZ_LINE)
+	if (Memc[cmd] == EOS) {
+	    call sfree (sp)
+	    return
+	}
+
+	# Process the command.
+	ncmd = strdic (Memc[cmd], Memc[cmd], SZ_LINE, MISC)
+	switch (ncmd) {
+	case ACMD_SHOW:
+	    call gargwrd (Memc[cmd], SZ_LINE)
+	    ncmd = strdic (Memc[cmd], Memc[cmd], SZ_LINE, CSHOWARGS)
+	    switch (ncmd) {
+	    case CCMD_DATA:
+		call printf ("\n")
+		call ap_nshow (ap)
+		call printf ("\n")
+	    case CCMD_CENTER:
+		call printf ("\n")
+	        call ap_cpshow (ap)
+		call printf ("\n")
+	    default:
+		call printf ("\n")
+	        call ap_cshow (ap)
+		call printf ("\n")
+	    }
+	case ACMD_RADPLOTS:
+	    call gargb (bval)
+	    if (nscan () == 1) {
+		call printf ("%s = %b\n")
+		    call pargstr (KY_RADPLOTS)
+		    call pargb (itob (apstati (ap, RADPLOTS)))
+	    } else {
+		call apseti (ap, RADPLOTS, btoi (bval))
+	    }
+	default:
+	    call printf ("Unknown or ambiguous colon command\7\n")
+	}
+
+	call sfree (sp)
+end
diff --git a/noao/digiphot/apphot/center/apcenter.x b/noao/digiphot/apphot/center/apcenter.x
new file mode 100644
index 00000000..8e1b4c68
--- /dev/null
+++ b/noao/digiphot/apphot/center/apcenter.x
@@ -0,0 +1,357 @@
+include <ctype.h>
+include <gset.h>
+include <imhdr.h>
+include "../lib/apphot.h"
+include "../lib/display.h"
+include "../lib/center.h"
+
+define	HELPFILE	"apphot$center/center.key"
+
+# APCENTER -- Procedure to determine accurate centers for a list of objects
+# interactively.
+
+int procedure apcenter (ap, im, cl, gd, mgd, id, out, stid, interactive, cache)
+
+pointer ap			# pointer to the apphot structure
+pointer	im			# pointer to the IRAF image
+int	cl			# coordinate list file descriptor
+pointer	gd			# pointer to the graphics stream
+pointer	mgd			# pointer to the plot metacode stream
+pointer	id			# pointer to the image display stream
+int	out			# output file descriptor
+int	stid			# output file sequence number
+int	interactive		# interactive mode
+int	cache			# cache the input pixels
+
+real	wx, wy, xlist, ylist
+pointer	sp, cmd
+int	wcs, key, colonkey, newimage, newobject, newcenter, newlist, ier, oid
+int	ip, prev_num, req_num, ltid, buf_size, old_size, req_size, memstat
+
+real	apstatr()
+int	ctoi(), clgcur(), apgscur(), apfitcenter(), aprefitcenter(), apstati()
+int	apgqverify(), apgtverify(), apnew(), ap_memstat(), sizeof()
+
+define	endswitch_ 99
+
+begin
+	call smark (sp)
+	call salloc (cmd, SZ_LINE, TY_CHAR)
+
+	# Initialize cursor command.
+	key = ' '
+	Memc[cmd] = EOS
+
+	# Initialize fitting parameters.
+	newimage = NO
+	newobject = YES
+	newcenter = YES
+	ier = AP_OK
+
+	# Initialize sequencing.
+	newlist = NO
+	ltid = 0
+
+	# Loop over the cursor commands.
+	while (clgcur ("icommands", wx, wy, wcs, key, Memc[cmd], SZ_LINE) !=
+	    EOF) {
+
+	    # Store the current cursor coordinates.
+	    call ap_vtol (im, wx, wy, wx, wy, 1)
+	    call apsetr (ap, CWX, wx)
+	    call apsetr (ap, CWY, wy)
+
+	    # Test to see if the cursor has moved.
+	    if (apnew (ap, wx, wy, xlist, ylist, newlist) == YES) {
+		newobject = YES
+		newcenter = YES
+	    }
+
+	    # Process the colon commands.
+	    switch (key) {
+
+	    # Quit.
+	    case 'q':
+		if (interactive == YES) {
+		    if (apgqverify ("center", ap, key) == YES) {
+			call sfree (sp)
+			return (apgtverify (key))
+		    }
+		} else {
+		    call sfree (sp)
+		    return (NO)
+		}
+
+	    # Print error messages.
+	    case 'e':
+		if (interactive == YES)
+		    call ap_cerrors (ap, ier)
+
+	    # Get information on keystroke commands.
+	    case '?':
+		if ((id != NULL) && (id == gd))
+		    call gpagefile (id, HELPFILE, "")
+		else if (interactive == YES)
+		    call pagefile (HELPFILE, "[space=cmhelp,q=quit,?=help]")
+
+	    # Rewind the coord list.
+	    case 'r':
+		if (cl != NULL) {
+		    call seek (cl, BOF)
+		    ltid = 0
+		} else if (interactive == YES)
+		    call printf ("No coordinate list\n")
+
+	    # Draw a centered stellar radial profile plot.
+	    case 'd':
+		if (interactive == YES) {
+		    call ap_qrad (ap, im, wx, wy, gd)
+		    newobject = YES
+		    newcenter = YES
+		}
+
+	    # Interactively set the centering parameters.
+	    case 'i':
+		if (interactive == YES) {
+		    call ap_cradsetup (ap, im, wx, wy, gd, out, stid)
+		    newobject = YES
+		    newcenter = YES
+		}
+
+	    # Verify critical parameters.
+	    case 'v':
+		call ap_cconfirm (ap, out, stid)
+		newobject = YES
+		newcenter = YES
+
+	    # Measure the next object.
+	    case 'm', 'n':
+
+		# No coordinate file.
+		if (cl == NULL) {
+		    if (interactive == YES)
+		        call printf ("No coordinate list\n")
+		    goto endswitch_
+		}
+
+		# Need to rewind coordinate file.
+		prev_num = ltid
+		req_num = ltid + 1
+		if (apgscur (cl, id, xlist, ylist, prev_num, req_num, ltid) ==
+		    EOF) {
+		    if (interactive == YES)
+			call printf (
+			    "End of coordinate list, use r key to rewind\n")
+		    goto endswitch_
+		}
+
+		# Convert coordinates if necessary.
+		switch (apstati (ap, WCSIN)) {
+		case WCS_PHYSICAL, WCS_WORLD:
+		    call ap_itol (ap,  xlist, ylist, xlist, ylist, 1)
+		case WCS_TV:
+		    call ap_vtol (im, xlist, ylist, xlist, ylist, 1)
+		default:
+		    ;
+		}
+
+		# Move to next object.
+		newlist = YES
+		if (key == 'm') {
+		    newobject = YES
+		    newcenter = YES
+		    goto endswitch_
+		} 
+
+		# Measure next object.
+		ier = apfitcenter (ap, im, xlist, ylist)
+		if (id != NULL) {
+		    call apmark (ap, id, apstati (ap, MKCENTER), NO, NO)
+		    if (id == gd)
+		        call gflush (id)
+		    else
+		        call gframe (id)
+		}
+		call ap_cplot (ap, stid, gd, apstati (ap, RADPLOTS))
+		if (interactive == YES)
+		    call ap_qcenter (ap, ier)
+		if (stid == 1)
+		     call ap_param (ap, out, "center")
+		call ap_cplot (ap, stid, mgd, YES)
+		call ap_pcenter (ap, out, stid, ltid, ier)
+		stid = stid + 1
+		newobject = NO
+		newcenter = NO
+
+	    # Save centering parameters in the pset files.
+	    case 'w':
+		call ap_pcpars (ap)
+
+	    # Process apphot : commands.
+	    case ':':
+		for (ip = 1; IS_WHITE(Memc[cmd+ip-1]); ip = ip + 1)
+		    ;
+		colonkey = Memc[cmd+ip-1]
+
+		# Process the apphot :n command.
+		switch (colonkey) {
+		case 'm', 'n':
+
+		    # Show/set apphot commands
+		    if (Memc[cmd+ip] != EOS && Memc[cmd+ip] != ' ') {
+		        call apcentercolon (ap, im, cl, out, stid, ltid,
+			    Memc[cmd], newimage, newobject, newcenter)
+			goto endswitch_
+		    }
+
+		    # No coordinate list.
+		    if (cl == NULL) {
+		        if (interactive == YES)
+		            call printf ("No coordinate list\n")
+			goto endswitch_
+		    }
+
+		    # Get next object from list.
+		    ip = ip + 1
+		    prev_num = ltid
+		    if (ctoi (Memc[cmd], ip, req_num) <= 0)
+		        req_num = ltid + 1
+
+		    # Fetch the next object from the list.
+		    if (apgscur (cl, id, xlist, ylist, prev_num, req_num,
+			    ltid) == EOF) {
+		        if (interactive == YES)
+			    call printf (
+			    "End of coordinate list, use r key to rewind\n")
+			goto endswitch_
+		    }
+
+		    # Convert the coordinates.
+		    switch (apstati (ap, WCSIN)) {
+		    case WCS_PHYSICAL, WCS_WORLD:
+		        call ap_itol (ap,  xlist, ylist, xlist, ylist, 1)
+		    case WCS_TV:
+		        call ap_vtol (im, xlist, ylist, xlist, ylist, 1)
+		    default:
+		        ;
+		    }
+
+		    # Move to the next object.
+		    newlist = YES
+		    if (colonkey == 'm') {
+		    	newobject = YES
+			newcenter = YES
+			goto endswitch_
+		    }
+
+		    # Measure next object.
+		    ier = apfitcenter (ap, im, xlist, ylist)
+		    if (id != NULL) {
+		        call apmark (ap, id, apstati (ap, MKCENTER), NO, NO)
+		    	if (id == gd)
+			   call gflush (id)
+		    	else
+		           call gframe (id)
+		    }
+		    call ap_cplot (ap, stid, gd, apstati (ap, RADPLOTS))
+		    if (interactive == YES)
+		        call ap_qcenter (ap, ier)
+		    if (stid == 1)
+		        call ap_param (ap, out, "center")
+		    call ap_cplot (ap, stid, mgd, YES)
+		    call ap_pcenter (ap, out, stid, ltid, ier)
+		    stid = stid + 1
+		    newobject = NO
+		    newcenter = NO
+
+		# Show/set apphot parameters.
+		default:
+		    call apcentercolon (ap, im, cl, out, stid, ltid, Memc[cmd],
+		        newimage, newobject, newcenter)
+		}
+
+		if (newimage == YES) {
+		    if ((id != NULL) && (id != gd))
+		        call ap_gswv (id, Memc[cmd], im, 4)
+		    req_size = MEMFUDGE * IM_LEN(im,1) * IM_LEN(im,2) *
+			sizeof (IM_PIXTYPE(im))
+		    memstat = ap_memstat (cache, req_size, old_size)
+		    if (memstat == YES)
+		        call ap_pcache (im, INDEFI, buf_size)
+		}
+
+		newimage = NO
+
+	    # Fit the center, and save the results.
+	    case 'f',  ' ':
+
+		# Compute the center.
+		if (newobject == YES)
+		    ier = apfitcenter (ap, im, wx, wy)
+		else if (newcenter == YES)
+		    ier = aprefitcenter (ap, im, ier)
+		if (id != NULL) {
+		    call apmark (ap, id, apstati (ap, MKCENTER), NO, NO)
+		    if (id == gd)
+			call gflush (id)
+		    else
+		        call gframe (id)
+		}
+		call ap_cplot (ap, stid, gd, apstati (ap, RADPLOTS))
+		if (interactive == YES)
+		    call ap_qcenter (ap, ier)
+		newobject = NO; newcenter = NO
+
+		# Write the results to the output file(s).
+		if (key == ' ') {
+		    if (stid == 1)
+		        call ap_param (ap, out, "center")
+		    if (newlist == YES)
+		        call ap_pcenter (ap, out, stid, ltid, ier)
+		    else
+		        call ap_pcenter (ap, out, stid, 0, ier)
+		    call ap_cplot (ap, stid, mgd, YES)
+		    stid = stid + 1
+		}
+
+	    # Fit centers for the rest of the list.
+	    case 'l':
+
+		# No coordinate list.
+		if (cl == NULL) {
+		    if (interactive == YES)
+		        call printf ("No coordinate list\n")
+		    goto endswitch_
+		}
+
+		# Center rest of coordinate list.
+		ltid = ltid + 1
+		oid = stid
+		call apbcenter (ap, im, cl, out, stid, ltid, mgd, id, YES)
+		ltid = ltid + stid - oid + 1
+		if (id != NULL) {
+		    if (id == gd)
+		        call gflush (id)
+		    else
+		        call gframe (id)
+		}
+
+	    # Unknown command.
+	    default:
+		call printf ("Unknown or ambiguous keystroke command\n")
+	    }
+
+endswitch_
+	    # Setup for the next object by setting the default keystroke
+	    # command and storing the old cursor coordinates in the 
+	    # centering structure.
+
+	    key = ' '
+	    Memc[cmd] = EOS
+	    call apsetr (ap, WX, apstatr (ap, CWX))
+	    call apsetr (ap, WY, apstatr (ap, CWY))
+
+	}
+
+	call sfree (sp)
+end
diff --git a/noao/digiphot/apphot/center/apcerrors.x b/noao/digiphot/apphot/center/apcerrors.x
new file mode 100644
index 00000000..4f8c32bb
--- /dev/null
+++ b/noao/digiphot/apphot/center/apcerrors.x
@@ -0,0 +1,32 @@
+include "../lib/center.h"
+
+# AP_CERRORS -- Procedure to print the centering task error messages.
+
+procedure ap_cerrrors (ap, ier)
+
+pointer	ap		# apphot pointer (unused)
+int	ier		# centering error code
+
+begin
+	switch (ier) {
+	case AP_CTR_NOAREA:
+	    call printf ("There are no pixels in the centering box.\n")
+        case AP_CTR_OUTOFBOUNDS:
+	    call printf (
+	        "The centering region is partially outside the image.\n")
+	case AP_CTR_NTOO_SMALL:
+	    call printf ("The centering box has too few points.\n")
+	case AP_CTR_SINGULAR:
+	    call printf ("The centering solution is singular.\n")
+	case AP_CTR_NOCONVERGE:
+	    call printf ("The centering algorithm does not converge.\n")
+	case AP_CTR_BADSHIFT:
+	    call printf ("The center shift is large.\n")
+	case AP_CTR_LOWSNRATIO:
+	    call printf ("The signal to noise ratio is low.\n")
+	case AP_CTR_BADDATA:
+	    call printf ("Bad data in the centering subraster.\n")
+	default:
+	    call printf ("")
+	}
+end
diff --git a/noao/digiphot/apphot/center/apcfree.x b/noao/digiphot/apphot/center/apcfree.x
new file mode 100644
index 00000000..7fb219c7
--- /dev/null
+++ b/noao/digiphot/apphot/center/apcfree.x
@@ -0,0 +1,46 @@
+include "../lib/apphotdef.h"
+include "../lib/centerdef.h"
+
+# APCFREE -- Procedure to free the centering data structure.
+
+procedure apcfree (ap)
+
+pointer	ap		# pointer to the apphot structure
+
+begin
+	if (ap == NULL)
+	    return
+	if (AP_NOISE(ap) != NULL)
+	    call ap_noisecls (ap)
+	if (AP_PCENTER(ap) != NULL)
+	    call ap_ctrcls (ap)
+	if (AP_PDISPLAY(ap) != NULL)
+	    call ap_dispcls (ap)
+	if (AP_IMBUF(ap) != NULL)
+	    call mfree (AP_IMBUF(ap), TY_REAL)
+	if (AP_MW(ap) != NULL)
+	    call mw_close (AP_MW(ap))
+	call mfree (ap, TY_STRUCT)
+end
+
+
+# AP_CTRCLS -- Procedure to close up the centering structure arrays.
+
+procedure ap_ctrcls (ap)
+
+pointer	ap			# pointer to apphot structure
+
+pointer	ctr
+
+begin
+	ctr = AP_PCENTER(ap)
+	if (ctr == NULL)
+	    return
+	if (AP_CTRPIX(ctr) != NULL)
+	    call mfree (AP_CTRPIX(ctr), TY_REAL)
+	if (AP_XCTRPIX(ctr) != NULL)
+	    call mfree (AP_XCTRPIX(ctr), TY_REAL)
+	if (AP_YCTRPIX(ctr) != NULL)
+	    call mfree (AP_YCTRPIX(ctr), TY_REAL)
+	call mfree (AP_PCENTER(ap), TY_STRUCT)
+end
diff --git a/noao/digiphot/apphot/center/apcinit.x b/noao/digiphot/apphot/center/apcinit.x
new file mode 100644
index 00000000..a9f38fd7
--- /dev/null
+++ b/noao/digiphot/apphot/center/apcinit.x
@@ -0,0 +1,94 @@
+include "../lib/apphotdef.h"
+include "../lib/centerdef.h"
+include "../lib/center.h"
+
+# APCINIT - Procedure to initialize the centering structure.
+
+procedure apcinit (ap, function, cbox, fwhmpsf, noise)
+
+pointer	ap		# pointer to the apphot structure
+int	function	# centering algorithm
+real	cbox		# half width of centering box
+real	fwhmpsf		# FWHM of the PSF
+int	noise		# noise function
+
+begin
+	# Allocate space.
+	call malloc (ap, LEN_APSTRUCT, TY_STRUCT)
+
+	# Set up the global apphot package parameters.
+	call ap_defsetup (ap, fwhmpsf)
+
+	# Setup the noise structure.
+	call ap_noisesetup (ap, noise)
+	    
+	# Initialize the centering parameters.
+	call ap_ctrsetup (ap, function, cbox)
+
+	# Display the options.
+	call ap_dispsetup (ap)
+
+	# Unused structures are set to null.
+	AP_PSKY(ap) = NULL
+	AP_PPSF(ap) = NULL
+	AP_PPHOT(ap) = NULL
+	AP_POLY(ap) = NULL
+	AP_RPROF(ap) = NULL
+end
+
+
+# AP_CTRSETUP -- Procedure to setup the centering array parameters.
+
+procedure ap_ctrsetup (ap, function, cbox)
+
+pointer	ap		# pointer to apphot structure
+int	function	# centering function
+real	cbox		# radius of centering aperture
+
+pointer	ctr
+
+begin
+	# Allocate space for the centering structure.
+	call malloc (AP_PCENTER(ap), LEN_CENSTRUCT, TY_STRUCT)
+	ctr = AP_PCENTER(ap)
+	AP_CXCUR(ctr) = INDEFR
+	AP_CYCUR(ctr) = INDEFR
+
+	AP_CENTERFUNCTION(ctr) = function
+	switch (function) {
+	case AP_CENTROID1D:
+	    call strcpy ("centroid", AP_CSTRING(ctr), SZ_FNAME)
+	case AP_GAUSS1D:
+	    call strcpy ("gauss", AP_CSTRING(ctr), SZ_FNAME)
+	case AP_NONE:
+	    call strcpy ("none", AP_CSTRING(ctr), SZ_FNAME)
+	case AP_OFILT1D:
+	    call strcpy ("ofilter", AP_CSTRING(ctr), SZ_FNAME)
+	default:
+	    AP_CENTERFUNCTION(ctr) = DEF_CENTERFUNCTION
+	    call strcpy ("centroid", AP_CSTRING(ctr), SZ_FNAME)
+	}
+	AP_CAPERT(ctr) = cbox
+	AP_CTHRESHOLD(ctr) = DEF_CTHRESHOLD
+	AP_MINSNRATIO(ctr) = DEF_MINSNRATIO
+	AP_CMAXITER(ctr) = DEF_CMAXITER
+	AP_MAXSHIFT(ctr) = DEF_MAXSHIFT
+	AP_CLEAN(ctr) = DEF_CLEAN
+	AP_RCLEAN(ctr) = DEF_RCLEAN
+	AP_RCLIP(ctr) = DEF_RCLIP
+	AP_SIGMACLEAN(ctr) = DEF_CLEANSIGMA
+
+	AP_NCTRPIX(ctr) = 0
+	AP_CTRPIX(ctr) = NULL
+	AP_XCTRPIX(ctr) = NULL
+	AP_YCTRPIX(ctr) = NULL
+
+	AP_OXINIT(ctr) = INDEFR
+	AP_OYINIT(ctr) = INDEFR
+	AP_XCENTER(ctr) = INDEFR
+	AP_YCENTER(ctr) = INDEFR
+	AP_OXCENTER(ctr) = INDEFR
+	AP_OYCENTER(ctr) = INDEFR
+	AP_XERR(ctr) = INDEFR
+	AP_YERR(ctr) = INDEFR
+end
diff --git a/noao/digiphot/apphot/center/apclean.x b/noao/digiphot/apphot/center/apclean.x
new file mode 100644
index 00000000..2e3a827a
--- /dev/null
+++ b/noao/digiphot/apphot/center/apclean.x
@@ -0,0 +1,152 @@
+include "../lib/apphot.h"
+include "../lib/noise.h"
+include "../lib/center.h"
+
+# AP_CLEAN -- Procedure to clean a data array.
+
+procedure ap_clean (ap, pix, nx, ny, xc, yc)
+
+pointer	ap		# pointer to the apphot structure
+real	pix[nx,ny]	# data array
+int	nx, ny		# size of subarray
+real	xc, yc		# center of subarray
+
+int	apstati()
+real	apstatr()
+
+begin
+	switch (apstati (ap, NOISEFUNCTION)) {
+	case AP_NCONSTANT:
+	    call ap_cclean (pix, nx, ny, xc, yc, apstatr (ap, SCALE) *
+	        apstatr (ap, RCLIP), apstatr (ap, SIGMACLEAN),
+		apstatr (ap, SKYSIGMA), apstatr (ap, MAXSHIFT))
+	case AP_NPOISSON:
+	    call ap_pclean (pix, nx, ny, xc, yc, apstatr (ap, SCALE) *
+		apstatr (ap, RCLEAN), apstatr (ap, SCALE) * apstatr (ap,
+		RCLIP), apstatr (ap, SIGMACLEAN), apstatr (ap, SKYSIGMA),
+		apstatr (ap, EPADU), apstatr (ap, MAXSHIFT))
+	default:
+	    return
+	}
+end
+
+
+# AP_CCLEAN -- Procedure to clean the subraster assuming the noise is
+# due to a constant sky sigma.
+
+procedure ap_cclean (pix, nx, ny, cxc, cyc, rclip, kclean, skysigma,
+    maxshift)
+
+real	pix[nx, ny]		# array of pixels
+int	nx, ny			# dimensions of the subarray
+real	cxc, cyc		# initial center
+real	rclip			# cleaning and clipping radius
+real	kclean			# k-sigma clipping factor
+real	skysigma		# maxshift
+real	maxshift		# maximum shift
+
+int	i, ii, ixc, j, jj, jyc, ijunk, jjunk
+real	mindat, maxdat, rclip2, r2, ksigma 
+
+begin
+	# Return if indef valued sigma or sigma <= 0.
+	if (IS_INDEFR(skysigma) || (skysigma <= 0.0))
+	    return
+
+	# Find the maximum pixel in the subarray and treat this point as
+	# the center of symmetry if it is less than maxshift from the
+	# initial center.
+
+	call ap_2dalimr (pix, nx, ny, mindat, maxdat, ijunk, jjunk, ixc, jyc)
+	if (abs (cxc - ixc) > maxshift || abs (cyc - jyc) > maxshift) {
+	    ixc = int (cxc)
+	    jyc = int (cyc)
+	}
+
+	# Clip.
+	rclip2 = rclip ** 2
+	ksigma = kclean * skysigma
+	do j = 1, ny {
+	    jj = 2 * jyc - j
+	    if (jj < 1 || jj > ny)
+		next
+	    do i = 1, ixc {
+		ii = 2 * ixc - i
+		if (ii < 1 || ii > nx)
+		    next
+		r2 = (i - ixc) ** 2 + (j - jyc) ** 2
+		if (r2 > rclip2) {
+		    if (pix[ii,jj] > pix[i,j] + ksigma)
+			pix[ii,jj] = pix[i,j]
+		    else if (pix[i,j] > pix[ii,jj] + ksigma)
+			pix[i,j] = pix[ii,jj]
+		}
+	    }
+	}
+end
+
+
+# AP_PCLEAN -- Procedure to clean the subraster assuming that the noise is
+# due to a constant sky value plus poisson noise.
+
+procedure ap_pclean (pix, nx, ny, cxc, cyc, rclean, rclip, kclean, skysigma,
+    padu, maxshift)
+
+real	pix[nx, ny]		# array of pixels
+int	nx, ny			# dimensions of the subarray
+real	cxc, cyc		# initial center
+real	rclean, rclip		# cleaning and clipping radius
+real	kclean			# k-sigma clipping factor
+real	skysigma		# maxshift
+real	padu			# photons per adu
+real	maxshift		# maximum shift
+
+int	i, ii, ixc, j, jj, jyc, ijunk, jjunk
+real	mindat, maxdat, rclean2, rclip2, r2, ksigma, ksigma2 
+
+begin
+	# Return if indef-valued sigma.
+	if (IS_INDEFR(skysigma))
+	    return
+
+	# Find the maximum pixel in the subarray and treat this point as
+	# the center of symmetry if it is less than maxshift from the
+	# initial center.
+
+	call ap_2dalimr (pix, nx, ny, mindat, maxdat, ijunk, jjunk, ixc, jyc)
+	if (abs (cxc - ixc) > maxshift || abs (cyc - jyc) > maxshift) {
+	    ixc = int (cxc)
+	    jyc = int (cyc)
+	}
+
+	# Clip.
+	rclean2 = rclean ** 2
+	rclip2 = rclip ** 2
+	ksigma = kclean * skysigma
+	ksigma2 = ksigma ** 2
+	do j = 1, ny {
+	    jj = 2 * jyc - j
+	    if (jj < 1 || jj > ny)
+		next
+	    do i = 1, ixc {
+		ii = 2 * ixc - i
+		if (ii < 1 || ii > nx)
+		    next
+		r2 = (i - ixc) ** 2 + (j - jyc) ** 2
+		if (r2 > rclean2 && r2 <= rclip2) {
+		    if (pix[ii,jj] > (pix[i,j] + sqrt (pix[i,j] / padu +
+		        ksigma2)))
+			pix[ii,jj] = pix[i,j]
+		    else if (pix[i,j] > (pix[ii,jj] + sqrt (pix[ii,jj] / padu +
+		        ksigma2)))
+			pix[i,j] = pix[ii,jj]
+		}
+		if (r2 > rclip2) {
+		    if (pix[ii,jj] > pix[i,j] + ksigma)
+			pix[ii,jj] = pix[i,j]
+		    else if (pix[i,j] > pix[ii,jj] + ksigma)
+			pix[i,j] = pix[ii,jj]
+		}
+	    }
+	}
+end
diff --git a/noao/digiphot/apphot/center/apcplot.x b/noao/digiphot/apphot/center/apcplot.x
new file mode 100644
index 00000000..6e2845c3
--- /dev/null
+++ b/noao/digiphot/apphot/center/apcplot.x
@@ -0,0 +1,304 @@
+include <mach.h>
+include <gset.h>
+include <pkg/gtools.h>
+include "../lib/apphotdef.h"
+include "../lib/apphot.h"
+include "../lib/noise.h"
+include "../lib/centerdef.h"
+include "../lib/center.h"
+
+# AP_CPLOT -- Procedure to compute radial profile plots for the centering
+# routine.
+
+procedure ap_cplot (ap, sid, gd, makeplot)
+
+pointer	ap		# the pointer to the apphot structure
+int	sid		# the output sequence number of the star
+pointer	gd		# the graphics stream
+int	makeplot	# the make a plot ?
+
+int	nx, ny
+pointer	ctr, sp, str, r, gt
+real	xcenter, ycenter, xc, yc, rmin, rmax, imin, imax
+real	u1, u2, v1, v2, x1, x2, y1, y2
+int	apstati()
+pointer	ap_gtinit()
+real	apstatr()
+
+begin
+	# Check for enabled graphics stream.
+	if (gd == NULL || makeplot == NO)
+	    return
+
+	# Check for defined center.
+	xcenter = apstatr (ap, XCENTER)
+	ycenter = apstatr (ap, YCENTER)
+	if (IS_INDEFR(xcenter) || IS_INDEFR(ycenter))
+	    return
+
+	# Check for a centering algorithm.
+	if (apstati (ap, CENTERFUNCTION) == AP_NONE)
+	    return
+
+	# Get the pixel buffer parameters.
+	ctr = AP_PCENTER(ap)
+	nx = AP_CNX(ctr)
+	ny = AP_CNY(ctr)
+	if (AP_CTRPIX(ctr) == NULL || nx <= 0 || ny <= 0)
+	    return
+	xc = AP_CXC(ctr) + (xcenter - apstatr (ap, CXCUR))
+	yc = AP_CYC(ctr) + (ycenter - apstatr (ap, CYCUR))
+
+	# Allocate working space.
+	call smark (sp)
+	call salloc (str, SZ_LINE, TY_CHAR)
+	call salloc (r, nx * ny, TY_REAL)
+
+	# Compute the radii and the plot limits.
+	call ap_ijtor2 (Memr[r], nx, ny, xc, yc)
+	call alimr (Memr[r], nx * ny, rmin, rmax)
+	call alimr (Memr[AP_CTRPIX(ctr)], nx * ny, imin, imax)
+
+	# Reactivate the work station.
+	call greactivate (gd, 0)
+
+	# Save old viewport and window coordinates.
+	call ggview (gd, u1, u2, v1, v2)
+	call ggwind (gd, x1, x2, y1, y2)
+
+	# Initialize the plot.
+	call apstats (ap, IMROOT, Memc[str], SZ_LINE)
+	call sprintf (Memc[str], SZ_LINE, "%s  Star %d")
+	    call pargstr (Memc[str])
+	    call pargi (sid)
+	gt = ap_gtinit (Memc[str], apstatr (ap,OXINIT), apstatr (ap, OYINIT))
+
+	# Make the plot.
+	call gclear (gd)
+	call ap_cpset (gd, gt, ap, rmin, rmax, imin, imax)
+	if (apstati (ap, POSITIVE) == YES)
+	    call ap_plotpts (gd, gt, Memr[r], Memr[AP_CTRPIX(ctr)], nx * ny,
+	        rmin, rmax, imin + EPSILONR, imax, "plus")
+	else
+	    call ap_plotpts (gd, gt, Memr[r], Memr[AP_CTRPIX(ctr)], nx * ny,
+	        rmin, rmax, imin, imax - EPSILONR, "plus")
+	call ap_cpreset (gd, gt, ap, rmin, rmax, imin, imax)
+	call ap_cpannotate (gd, ap)
+
+	# Restore the viewport and window coordinates.
+	call gsview (gd, u1, u2, v1, v2)
+	call gswind (gd, x1, x2, y1, y2)
+
+	# Free the space.
+	call ap_gtfree (gt)
+	call gdeactivate (gd, 0)
+	call sfree (sp)
+end
+
+
+# AP_CPSET -- Procedure to set up the parameters for the center radial profile
+# plot.
+
+procedure ap_cpset (gd, gt, ap, xmin, xmax, ymin, ymax)
+
+pointer	gd		# the graphics stream
+pointer	gt		# the gtools pointer
+pointer	ap		# the apphot pointer
+real	xmin, xmax	# the minimum and maximum radial distance
+real	ymin, ymax	# the minimum and maximum of y axis (ymin not used)
+
+int	fd
+pointer	sp, str, title
+real	scale, aspect, datalimit, skysigma, threshold, vx1, vx2, vy1, vy2
+real	cthreshold
+int	stropen(), apstati()
+real	apstatr(), gstatr()
+
+begin
+	call smark (sp)
+	call salloc (str, SZ_LINE, TY_CHAR)
+	call salloc (title, SZ_LINE, TY_CHAR)
+
+	# Encode the parameter string.
+	fd = stropen (Memc[str], SZ_LINE, WRITE_ONLY)
+	call sysid (Memc[title], SZ_LINE)
+	call fprintf (fd, "%s\n")
+	    call pargstr (Memc[title])
+	call fprintf (fd,
+	    "Center: xc=%0.2f yc=%0.2f xerr=%0.2f yerr=%0.2f\n")
+	    call pargr (apstatr (ap, OXCENTER))
+	    call pargr (apstatr (ap, OYCENTER))
+	    call pargr (apstatr (ap, XERR))
+	    call pargr (apstatr (ap, YERR))
+	call gt_gets (gt, GTTITLE, Memc[title], SZ_LINE)
+	call fprintf (fd, "%s\n")
+	    call pargstr (Memc[title])
+	call strclose (fd)
+
+	# Store some default plotting parameters.
+	scale = apstatr (ap, SCALE)
+	aspect = gstatr (gd, G_ASPECT)
+	call gsetr (gd, G_ASPECT, 0.75)
+
+	# Set the labels and window.
+	datalimit = apstatr (ap, CDATALIMIT)
+	skysigma = apstatr (ap, SKYSIGMA)
+	cthreshold = apstatr (ap, CTHRESHOLD)
+	if (IS_INDEFR(skysigma) || IS_INDEFR(cthreshold))
+	    threshold = 0.0
+	else
+	    threshold = cthreshold * skysigma
+	if (apstati (ap, POSITIVE) == YES) {
+	    call gseti (gd, G_XDRAWAXES, 2)
+	    call gswind (gd, xmin / scale, xmax / scale, datalimit + threshold,
+		datalimit + threshold + ymax)
+	    call glabax (gd, Memc[str], "", "Intensity")
+	    call gseti (gd, G_YDRAWAXES, 0)
+	    call gseti (gd, G_XDRAWAXES, 1)
+	    call ggview (gd, vx1, vx2, vy1, vy2)
+	    call gswind (gd, vx1, vx2, vy1, vy2)
+	    call gswind (gd, xmin, xmax, datalimit + threshold,
+		datalimit + threshold + ymax)
+	    call glabax (gd, "",
+	        "Radial Distance (lower-pixels, upper-scale units)", "")
+	} else {
+	    call gseti (gd, G_XDRAWAXES, 2)
+	    call gswind (gd, xmin / scale, xmax / scale, datalimit -
+	        threshold - ymax, datalimit - threshold)
+	    call glabax (gd, Memc[str], "", "Intensity")
+	    call gseti (gd, G_YDRAWAXES, 0)
+	    call gseti (gd, G_XDRAWAXES, 1)
+	    call ggview (gd, vx1, vx2, vy1, vy2)
+	    call gswind (gd, vx1, vx2, vy1, vy2)
+	    call gswind (gd,  xmin,  xmax, datalimit - threshold - ymax,
+	        datalimit - threshold)
+	    call glabax (gd, "",
+	        "Radial Distance (lower-pixels, upper-scale units)", "")
+	}
+
+	# Set the window up for plotting the data.
+	call gseti (gd, G_YDRAWAXES, 3)
+	call gseti (gd, G_XDRAWAXES, 3)
+	call gsetr (gd, G_ASPECT, aspect)
+	call gt_sets (gt, GTTYPE, "mark")
+	call gt_setr (gt, GTXMIN, xmin)
+	call gt_setr (gt, GTXMAX, xmax)
+	if (apstati (ap, POSITIVE) == YES) {
+	    call gt_setr (gt, GTYMIN, ymin)
+	    call gt_setr (gt, GTYMAX, ymax)
+	} else {
+	    call gt_setr (gt, GTYMIN, ymin)
+	    call gt_setr (gt, GTYMAX, ymax)
+	}
+	call gt_swind (gd, gt)
+
+	call sfree (sp)
+end
+
+
+# AP_CPANNOTATE -- Procedure to annotate the radial plot in center.
+
+procedure ap_cpannotate (gd, ap)
+
+pointer	gd		# the graphics stream
+pointer	ap		# the apphot structure
+
+pointer	sp, str
+real	fwhmpsf, capert, datalimit, threshold, skysigma, cthreshold
+real	xmin, xmax, ymin, ymax
+int	apstati()
+real	apstatr()
+
+begin
+	# Allocate working space.
+	call smark (sp)
+	call salloc (str, SZ_LINE, TY_CHAR)
+	call gseti (gd, G_PLTYPE, GL_DASHED)
+	call ggwind (gd, xmin, xmax, ymin, ymax)
+
+	fwhmpsf = 0.5 * apstatr (ap, FWHMPSF) * apstatr (ap, SCALE)
+	capert = 2.0 * fwhmpsf * apstatr (ap, CAPERT)
+	datalimit = apstatr (ap, CDATALIMIT)
+	skysigma = apstatr (ap, SKYSIGMA)
+	cthreshold = apstatr (ap, CTHRESHOLD)
+	if (IS_INDEFR(skysigma) || IS_INDEFR(cthreshold))
+	    threshold = 0.0
+	else
+	    threshold = cthreshold * skysigma
+	if (apstati (ap, POSITIVE) == YES)
+	    threshold = datalimit + threshold
+	else
+	    threshold = datalimit - threshold
+
+	# Plot the full width half maximum of the radial profile.
+	if (fwhmpsf >= xmin && fwhmpsf <= xmax) {
+	    call gamove (gd, fwhmpsf, ymin)
+	    call gadraw (gd, fwhmpsf, ymax)
+	    call sprintf (Memc[str], SZ_LINE, "hwhm = %0.2f")
+	        call pargr (fwhmpsf)
+	    call gtext (gd, fwhmpsf, ymax, Memc[str], "q=h;u=180;v=t;p=r")
+	}
+
+	# Mark the centering aperture.
+	if (capert >= xmin && capert <= xmax) {
+	    call gamove (gd, capert, ymin)
+	    call gadraw (gd, capert, ymax)
+	    call sprintf (Memc[str], SZ_LINE, "cbox half-width = %0.2f")
+	        call pargr (capert)
+	    call gtext (gd, capert, ymax, Memc[str], "q=h;u=180;v=t;p=r")
+	}
+
+	# Mark the threshold level for centering.
+        call sprintf (Memc[str], SZ_LINE, "threshold = %g")
+	    call pargr (threshold)
+	call gtext (gd, xmin, ymin, Memc[str], "q=h")
+
+	# Mark the sky sigma if defined.
+	if (! IS_INDEFR(skysigma) && skysigma >= ymin && skysigma <= ymax) {
+	    call gmark (gd, (xmin + xmax) / 2.0, (ymin + ymax) / 2.0, 
+		GM_VEBAR, -0.25, -skysigma)
+	    call sprintf (Memc[str], SZ_LINE, "sigma = %g")
+		call pargr (skysigma)
+	    call gtext (gd, (xmin + xmax) / 2.0, (ymin + ymax + skysigma) / 2.0,
+		Memc[str], "q=h;h=c")
+	}
+
+	call sfree (sp)
+end
+
+
+# AP_CPRSET -- Procedure to reset the plot window after the data points
+# have been plotted.
+
+procedure ap_cpreset (gd, gt, ap, xmin, xmax, ymin, ymax)
+
+pointer	gd		# the graphics stream
+pointer	gt		# the gtools pointer
+pointer	ap		# the apphot pointer
+real	xmin, xmax	# the minimum and maximum radial distance
+real	ymin, ymax	# the minimum and maximum of the y axis (ymin not used)
+
+real	datalimit, skysigma, threshold, cthreshold
+int	apstati()
+real	apstatr()
+
+begin
+	# Set the data window.
+	datalimit = apstatr (ap, CDATALIMIT)
+	skysigma = apstatr (ap, SKYSIGMA)
+	cthreshold = apstatr (ap, CTHRESHOLD)
+	if (IS_INDEFR(skysigma) || IS_INDEFR(cthreshold))
+	    threshold = 0.0
+	else
+	    threshold = cthreshold * skysigma
+	call gt_setr (gt, GTXMIN, xmin)
+	call gt_setr (gt, GTXMAX, xmax)
+	if (apstati (ap, POSITIVE) == YES) {
+	    call gt_setr (gt, GTYMIN, datalimit + threshold)
+	    call gt_setr (gt, GTYMAX, ymax + datalimit + threshold)
+	} else {
+	    call gt_setr (gt, GTYMIN, datalimit - ymax - threshold)
+	    call gt_setr (gt, GTYMAX, datalimit - threshold)
+	}
+	call gt_swind (gd, gt)
+end
diff --git a/noao/digiphot/apphot/center/apcpshow.x b/noao/digiphot/apphot/center/apcpshow.x
new file mode 100644
index 00000000..79fdf43e
--- /dev/null
+++ b/noao/digiphot/apphot/center/apcpshow.x
@@ -0,0 +1,66 @@
+include "../lib/center.h"
+include "../lib/display.h"
+
+# AP_CPSHOW -- Procedure to display the current centering algorithm
+# parameters.
+
+procedure ap_cpshow (ap)
+
+pointer	ap	# pointer to the apphot strucuture
+
+pointer	sp, str
+bool	itob()
+int	apstati()
+real	apstatr()
+
+begin
+	call smark (sp)
+	call salloc (str, SZ_LINE, TY_CHAR)
+
+	# Print the centering algorithm.
+	call printf ("Centering Parameters\n")
+	call apstats (ap, CSTRING, Memc[str], SZ_FNAME)
+	call printf ("    %s = %s %s\n")
+	    call pargstr (KY_CSTRING)
+	    call pargstr (Memc[str])
+	    call pargstr (UN_CALGORITHM)
+
+	# Print the rest of the centering parameters.
+	call printf ("    %s = %g %s    %s = %g %s    %s = %g\n")
+	    call pargstr (KY_CAPERT)
+	    call pargr (2.0 * apstatr (ap, CAPERT))
+	    call pargstr (UN_CSCALEUNIT)
+	    call pargstr (KY_CTHRESHOLD)
+	    call pargr (apstatr (ap, CTHRESHOLD))
+	    call pargstr (UN_CSIGMA)
+	    call pargstr (KY_MINSNRATIO)
+	    call pargr (apstatr (ap, MINSNRATIO))
+
+	call printf ("    %s = %d    %s = %g %s\n")
+	    call pargstr (KY_CMAXITER)
+	    call pargi (apstati (ap, CMAXITER))
+	    call pargstr (KY_MAXSHIFT)
+	    call pargr (apstatr (ap, MAXSHIFT))
+	    call pargstr (UN_CNUMBER)
+
+	call printf ("    %s = %b    %s = %g %s\n")
+	    call pargstr (KY_CLEAN)
+	    call pargb (itob (apstati (ap, CLEAN)))
+	    call pargstr (KY_SIGMACLEAN)
+	    call pargr (apstatr (ap, SIGMACLEAN))
+	    call pargstr (UN_CSIGMA)
+
+	call printf ("    %s = %g %s    %s = %g %s\n")
+	    call pargstr (KY_RCLEAN)
+	    call pargr (apstatr (ap, RCLEAN))
+	    call pargstr (UN_CSCALEUNIT)
+	    call pargstr (KY_RCLIP)
+	    call pargr (apstatr (ap, RCLIP))
+	    call pargstr (UN_CSCALEUNIT)
+
+	call printf ("    %s = %b\n")
+	    call pargstr (KY_MKCENTER)
+	    call pargb (itob (apstati (ap, MKCENTER)))
+
+	call sfree (sp)
+end
diff --git a/noao/digiphot/apphot/center/apcradsetup.x b/noao/digiphot/apphot/center/apcradsetup.x
new file mode 100644
index 00000000..8902c5ef
--- /dev/null
+++ b/noao/digiphot/apphot/center/apcradsetup.x
@@ -0,0 +1,99 @@
+include "../lib/display.h"
+
+define	HELPFILE	"apphot$center/icenter.key"
+
+# AP_CRADSETUP -- Procedure to set up apphot interactively
+
+procedure ap_cradsetup (ap, im, wx, wy, gd, out, stid)
+
+pointer	ap			# pointer to apphot structure
+pointer	im			# pointero to the IRAF image
+real	wx, wy			# cursor coordinates
+pointer	gd			# pointer to graphics stream
+int	out			# output file descriptor
+int	stid			# output file sequence number
+
+int	cier, wcs, key
+pointer	sp, cmd
+real	xcenter, ycenter, xc, yc, rmin, rmax, imin, imax, rval
+real	u1, u2, v1, v2, x1, x2, y1, y2
+
+int	ap_showplot(), apfitcenter(), apstati(), clgcur()
+real	ap_cfwhmpsf(), ap_ccapert(), ap_csigma()
+real	ap_cdatamin(), ap_cdatamax(), ap_crclean(), ap_crclip()
+
+begin
+	# Check for open graphics stream.
+	if (gd == NULL)
+	    return
+	call greactivate (gd, 0)
+
+	# Store old viewport and window coordinates.
+	call ggview (gd, u1, u2, v1, v2)
+	call ggwind (gd, x1, x2, y1, y2)
+
+	# Make the plot.
+	if (ap_showplot (ap, im, wx, wy, gd, xcenter, ycenter, rmin, rmax,
+	    imin, imax) == ERR) {
+	    call gdeactivate (gd, 0)
+	    return
+	}
+
+	# Allocate temporary space.
+	call smark (sp)
+	call salloc (cmd, SZ_LINE, TY_CHAR)
+
+	call printf (
+	"Waiting for setup menu command (?=help, v=default setup, q=quit):\n")
+
+	while (clgcur ("gcommands", xc, yc, wcs, key, Memc[cmd],
+	    SZ_LINE) != EOF) {
+
+	switch (key) {
+	    case 'q':
+	        break
+	    case '?':
+		call gpagefile (gd, HELPFILE, "")
+	    case 'f':
+	        rval = ap_cfwhmpsf (ap, gd, out, stid, rmin, rmax, imin, imax)
+	    case 's':
+	        rval = ap_csigma (ap, gd, out, stid, rmin, rmax, imin, imax)
+	    case 'l':
+	        rval = ap_cdatamin (ap, gd, out, stid, rmin, rmax, imin, imax)
+	    case 'u':
+	        rval = ap_cdatamax (ap, gd, out, stid, rmin, rmax, imin, imax)
+	    case 'c':
+		rval = ap_ccapert (ap, gd, out, stid, rmin, rmax, imin, imax)
+	    case 'n':
+		rval = ap_crclean (ap, gd, out, stid, rmin, rmax, imin, imax)
+	    case 'p':
+		rval = ap_crclip (ap, gd, out, stid, rmin, rmax, imin, imax)
+	    case 'v':
+	        rval = ap_cfwhmpsf (ap, gd, out, stid, rmin, rmax, imin, imax)
+		rval = ap_ccapert (ap, gd, out, stid, rmin, rmax, imin, imax)
+	        rval = ap_csigma (ap, gd, out, stid, rmin, rmax, imin, imax)
+	        #rval = ap_ccthresh (ap, gd, out, stid, rmin, rmax, imin, imax)
+	    default:
+		call printf ("Unknown or ambiguous keystroke command\007\n")
+	    }
+	    call printf (
+	 "Waiting for setup menu command (?=help, v=default setup, q=quit):\n")
+	}
+
+	# Set up interactively.
+	call printf (
+	    "Interactive setup is complete [Type w to save parameters].\n")
+
+	# Restore old window and viewport coordinates.
+	call gsview (gd, u1, u2, v1, v2)
+	call gswind (gd, x1, x2, y1, y2)
+
+	# Free plots and working space.
+	call sfree (sp)
+	call gdeactivate (gd, 0)
+
+	# Fit the center and plot the results.
+	cier = apfitcenter (ap, im, xcenter, ycenter)
+	call ap_cplot (ap, 0, gd, apstati (ap, RADPLOTS))
+	call ap_qcenter (ap, cier)
+end
diff --git a/noao/digiphot/apphot/center/apcshow.x b/noao/digiphot/apphot/center/apcshow.x
new file mode 100644
index 00000000..8cedbfc2
--- /dev/null
+++ b/noao/digiphot/apphot/center/apcshow.x
@@ -0,0 +1,19 @@
+include "../lib/display.h"
+
+# AP_CSHOW -- Procedure to display the current centering parameters.
+
+procedure ap_cshow (ap)
+
+pointer	ap	# pointer to the apphot strucuture
+
+bool	itob()
+int	apstati()
+
+begin
+	call ap_nshow (ap)
+	call printf ("\n")
+	call ap_cpshow (ap)
+	call printf ("    %s = %b\n")
+	    call pargstr (KY_RADPLOTS)
+	    call pargb (itob (apstati (ap, RADPLOTS)))
+end
diff --git a/noao/digiphot/apphot/center/apcsnratio.x b/noao/digiphot/apphot/center/apcsnratio.x
new file mode 100644
index 00000000..0fd0e20d
--- /dev/null
+++ b/noao/digiphot/apphot/center/apcsnratio.x
@@ -0,0 +1,92 @@
+include <mach.h>
+include "../lib/center.h"
+include "../lib/noise.h"
+
+# AP_CSNRATIO -- Procedure to estimate the signal to noise ratio for centering.
+
+real procedure ap_csnratio (ap, array, nx, ny, threshold)
+
+pointer	ap		# apphot structure
+real	array[nx,ny]	# data array
+int	nx, ny		# subraster dimensions
+real	threshold	# threshold value for snr computation
+
+int	apstati()
+real	apstatr(), ap_cratio(), ap_pratio()
+
+begin
+	switch (apstati (ap, NOISEFUNCTION)) {
+	case AP_NCONSTANT:
+	    return (ap_cratio (array, nx, ny, threshold, apstatr (ap,
+	        SKYSIGMA)))
+	case AP_NPOISSON:
+	    return (ap_pratio (array, nx, ny, threshold, apstatr (ap,
+	        SKYSIGMA), apstatr (ap, EPADU)))
+	default:
+	    return (MAX_REAL)
+	}
+end
+
+
+# AP_CRATIO -- Procedure to estimate the signal to noise ratio in the
+# centering aperture assuming that the noise is due to a constant sky
+# sigma. These computations are approximate only.
+
+real procedure ap_cratio (array, nx, ny, sky, noise)
+
+real	array[nx,ny]		# centering buffer
+int	nx, ny			# dimensions of the centering buffer
+real	sky			# mean sky value of the data in ADU
+real	noise			# estimate of sky noise in ADU
+
+int	npts
+real	signal, tnoise
+real	asumr()
+
+begin
+	npts = nx * ny
+	signal = asumr (array, npts) - npts * sky
+	if (IS_INDEFR(noise))
+	    tnoise = 0.0
+	else
+	    tnoise = sqrt (npts * noise ** 2)
+	if (signal <= 0.0)
+	    return (0.0)
+	else if (tnoise <= 0.0)
+	    return (MAX_REAL)
+	else
+	    return (signal / tnoise)
+end
+
+
+# AP_PRATIO -- Procedure to estimate the signal to noise ratio in the
+# centering aperture assuming the noise is due to a constant sky sigma
+# and poisson statistics in the image. These computations are
+# approximate only.
+
+real procedure ap_pratio (array, nx, ny, sky, noise, padu)
+
+real	array[nx,ny]		# centering buffer
+int	nx, ny			# dimensions of the centering buffer
+real	sky			# mean sky value of the data in ADU
+real	noise			# estimate of sky noise in ADU
+real	padu			# photons per adu
+
+int	npts
+real	signal, tnoise
+real	asumr()
+
+begin
+	npts = nx * ny
+	signal = asumr (array, npts) - npts * sky
+	if (IS_INDEFR(noise))
+	    tnoise = sqrt (abs (signal / padu))
+	else
+	    tnoise = sqrt (abs (signal / padu) + npts * noise ** 2)
+	if (signal <= 0.0)
+	    return (0.0)
+	else if (tnoise <= 0.0)
+	    return (MAX_REAL)
+	else
+	    return (signal / tnoise)
+end
diff --git a/noao/digiphot/apphot/center/apctr1d.x b/noao/digiphot/apphot/center/apctr1d.x
new file mode 100644
index 00000000..10ee109e
--- /dev/null
+++ b/noao/digiphot/apphot/center/apctr1d.x
@@ -0,0 +1,113 @@
+include <mach.h>
+include "../lib/center.h"
+
+# AP_CTR1D -- Procedure to compute the center from the 1D marginal
+# distributions.
+
+int procedure ap_ctr1d (ctrpix, nx, ny, norm, xc, yc, xerr, yerr)
+
+real	ctrpix[nx, ny]		# object to be centered
+int	nx, ny			# dimensions of subarray
+real	norm			# the normalization factor
+real	xc, yc			# computed centers
+real	xerr, yerr		# estimate of centering error
+
+pointer	sp, xm, ym
+
+begin
+	call smark (sp)
+	call salloc (xm, nx, TY_REAL)
+	call salloc (ym, ny, TY_REAL)
+
+	# Compute the marginal distributions.
+	call ap_mkmarg (ctrpix, Memr[xm], Memr[ym], nx, ny)
+	call adivkr (Memr[xm], real (ny), Memr[xm], nx)
+	call adivkr (Memr[ym], real (nx), Memr[ym], ny)
+
+	# Get the centers and errors.
+	call ap_cmarg (Memr[xm], nx, norm, xc, xerr)
+	call ap_cmarg (Memr[ym], ny, norm, yc, yerr)
+
+	call sfree (sp)
+	return (AP_OK)
+end
+
+
+# AP_CMARG -- Compute the center and estimate its error given the
+# marginal distribution and the number of points.
+
+procedure ap_cmarg (a, npts, norm, xc, err)
+
+real	a[npts]		# array
+int	npts		# number of points
+real	norm		# the normalization factor
+real	xc		# center value
+real	err		# error
+
+int	i, npos
+real	val, sumi, sumix, sumix2
+
+begin
+	# Initialize.
+	npos = 0
+	sumi = 0.0
+	sumix = 0.0
+	sumix2 = 0.0
+
+	# Accumulate the sums.
+	do i = 1, npts {
+	    val = a[i]
+	    if (val > 0.0)
+	        npos = npos + 1
+	    sumi = sumi + val
+	    sumix = sumix + val * i
+	    sumix2 = sumix2 + val * i ** 2
+	}
+
+	# Compute the position and the error.
+	if (npos <= 0) {
+	    xc =  (1.0 + npts) / 2.0
+	    err = INDEFR
+	} else {
+	    xc = sumix / sumi
+	    err = (sumix2 / sumi - xc * xc)
+	    if (err <= 0.0) {
+		err = 0.0
+	    } else {
+	        err = sqrt (err / (sumi * norm))
+		if (err > real (npts))
+		    err = INDEFR
+	    }
+	}
+end
+
+
+# AP_MKMARG -- Accumulate the marginal distributions.
+
+procedure ap_mkmarg (ctrpix, xm, ym, nx, ny)
+
+real	ctrpix[nx, ny]		# pixels
+real	xm[nx]			# x marginal distribution
+real	ym[ny]			# y marginal distribution
+int	nx, ny			# dimensions of array
+
+int	i, j
+real	sum
+
+begin
+	# Compute the x marginal.
+	do i = 1, nx {
+	    sum = 0.0
+	    do j = 1, ny
+		sum = sum + ctrpix[i,j]
+	    xm[i] = sum
+	}
+
+	# Compute the y marginal.
+	do j = 1, ny {
+	    sum = 0.0
+	    do i = 1, nx
+		sum = sum + ctrpix[i,j]
+	    ym[j] = sum
+	}
+end
diff --git a/noao/digiphot/apphot/center/apctrbuf.x b/noao/digiphot/apphot/center/apctrbuf.x
new file mode 100644
index 00000000..0a8053b8
--- /dev/null
+++ b/noao/digiphot/apphot/center/apctrbuf.x
@@ -0,0 +1,115 @@
+include <imhdr.h>
+include <math.h>
+include <mach.h>
+include "../lib/apphotdef.h"
+include "../lib/centerdef.h"
+include "../lib/center.h"
+
+# APCTRBUF -- Procedure to fetch the center pixels given the pointer to the
+# IRAF image, the coordinates of the initial center and the width of the APPHOT
+# centering box.
+
+int procedure apctrbuf (ap, im, wx, wy)
+
+pointer	ap		# pointer to apphot structure
+pointer	im		# pointer to the IRAF image
+real	wx, wy		# center coordinates
+
+int	icpix
+pointer	ctr
+real	cpix, gdatamin, gdatamax, datamin, datamax
+pointer	ap_ctrpix()
+
+begin
+	# Get pointer to centering structure.
+	ctr = AP_PCENTER(ap)
+
+	# Check for 0 sized aperture.
+	if (AP_CAPERT(ctr) <= 0.0)
+	    return (AP_CTR_NOAREA)
+
+	# Get the centering buffer of pixels.
+	cpix = max (1.0, AP_CAPERT(ctr) * AP_SCALE(ap))
+	icpix = 2 * int (cpix) + 1
+	if (AP_CTRPIX(ctr) != NULL)
+	    call mfree (AP_CTRPIX(ctr), TY_REAL)
+	AP_CTRPIX(ctr) = ap_ctrpix (im, wx, wy, icpix,
+	    AP_CXC(ctr), AP_CYC(ctr), AP_CNX(ctr), AP_CNY(ctr))
+	if (AP_CTRPIX(ctr) == NULL)
+	    return (AP_CTR_NOAREA)
+
+	# Compute the data limits.
+	if (IS_INDEFR(AP_DATAMIN(ap)))
+	    gdatamin = -MAX_REAL
+	else
+	    gdatamin = AP_DATAMIN(ap)
+	if (IS_INDEFR(AP_DATAMAX(ap)))
+	    gdatamax = MAX_REAL
+	else
+	    gdatamax = AP_DATAMAX(ap)
+	call alimr (Memr[AP_CTRPIX(ctr)], AP_CNX(ctr) * AP_CNY(ctr),
+	    datamin, datamax)
+
+	if (datamin < gdatamin || datamax > gdatamax)
+	    return (AP_CTR_BADDATA)
+	else if (AP_CNX(ctr) < icpix || AP_CNY(ctr) < icpix)
+	    return (AP_CTR_OUTOFBOUNDS)
+	else
+	    return (AP_OK)
+end
+
+
+# AP_CTRPIX -- Procedure to fetch the pixels to be used for centering.
+
+pointer procedure ap_ctrpix (im, wx, wy, capert, xc, yc, nx, ny)
+
+pointer	im		# pointer to IRAF image
+real	wx, wy		# center of subraster to be extracted
+int	capert		# width of subraster to be extracted
+real	xc, yc		# center of extracted subraster
+int	nx, ny		# dimensions of extracted subraster
+
+int	i, ncols, nlines, c1, c2, l1, l2, half_capert
+pointer	buf, lbuf
+real	xc1, xc2, xl1, xl2
+pointer	imgs2r()
+
+begin
+	# Check for nonsensical input.
+	half_capert = (capert - 1) / 2
+	if (half_capert <= 0)
+	    return (NULL)
+
+	# Test for out of bounds pixels
+	ncols = IM_LEN(im,1)
+	nlines = IM_LEN(im,2)
+	xc1 = wx - half_capert
+	xc2 = wx + half_capert
+	xl1 = wy - half_capert
+	xl2 = wy + half_capert
+	if (xc1 > real (ncols) || xc2 < 1.0 || xl1 > real (nlines) || xl2 < 1.0)
+	    return (NULL)
+
+	# Get column and line limits, dimensions and center of subraster.
+	c1 = max (1.0, min (real (ncols), xc1)) + 0.5
+	c2 = min (real (ncols), max (1.0, xc2)) + 0.5
+	l1 = max (1.0, min (real (nlines), xl1)) + 0.5
+	l2 = min (real (nlines), max (1.0, xl2)) + 0.5
+	nx = c2 - c1 + 1
+	ny = l2 - l1 + 1
+	xc = wx - c1 + 1
+	yc = wy - l1 + 1
+
+	# Get pixels and return.
+	if (nx < 1 && ny < 1)
+	    return (NULL)
+	else {
+	    call malloc (buf, nx * ny, TY_REAL)
+	    lbuf = buf
+	    do i = l1, l2 {
+	        call amovr (Memr[imgs2r (im, c1, c2, i, i)], Memr[lbuf], nx)
+	        lbuf = lbuf + nx
+	    }
+	    return (buf)
+	}
+end
diff --git a/noao/digiphot/apphot/center/apfitcen.x b/noao/digiphot/apphot/center/apfitcen.x
new file mode 100644
index 00000000..bd7224e8
--- /dev/null
+++ b/noao/digiphot/apphot/center/apfitcen.x
@@ -0,0 +1,291 @@
+include <mach.h>
+include "../lib/apphotdef.h"
+include "../lib/apphot.h"
+include "../lib/noisedef.h"
+include "../lib/centerdef.h"
+include "../lib/center.h"
+
+define	CONVERT		.424660900	# conversion from fwhmpsf to sigma
+
+# APFITCENTER -- Procedure to fit the centers using either 1) the intensity
+# weighted mean of the marginal distributions, 2) a Gaussian fit to the
+# marginals assuming a fixed sigma or 3) a simplified version of the optimal
+# filtering method using a Gaussian of fixed sigma to model the profile.
+
+int procedure apfitcenter (ap, im, wx, wy)
+
+pointer	ap		# pointer to the apphot structure
+pointer	im		# pointer to the IRAF image
+real	wx, wy		# object coordinates
+
+int	i, niter, ier, fier, lowsnr
+pointer	ctr, nse
+real	cthreshold, datamin, datamax, owx, owy, xshift, yshift, med
+int	apctrbuf(), ap_ctr1d(), ap_mctr1d(), ap_gctr1d(), ap_lgctr1d()
+real	ap_csnratio(), amedr()
+
+begin
+	ctr = AP_PCENTER(ap)
+	nse = AP_NOISE(ap)
+	ier = AP_OK
+
+	# Initialize.
+	AP_CXCUR(ctr) = wx
+	AP_CYCUR(ctr) = wy
+	AP_OXINIT(ctr) = INDEFR
+	AP_OYINIT(ctr) = INDEFR
+	AP_XCENTER(ctr) = INDEFR
+	AP_YCENTER(ctr) = INDEFR
+	AP_OXCENTER(ctr) = INDEFR
+	AP_OYCENTER(ctr) = INDEFR
+	AP_XSHIFT(ctr) = 0.0
+	AP_YSHIFT(ctr) = 0.0
+	AP_OXSHIFT(ctr) = 0.0
+	AP_OYSHIFT(ctr) = 0.0
+	AP_XERR(ctr) = INDEFR
+	AP_YERR(ctr) = INDEFR
+
+	# Return input coordinates if centering is disabled.
+	if (IS_INDEFR(wx) || IS_INDEFR(wy)) {
+	    return (AP_CTR_NOAREA)
+	} else if (AP_CENTERFUNCTION(ctr) == AP_NONE) {
+	    AP_XCENTER(ctr) = wx
+	    AP_YCENTER(ctr) = wy
+	    switch (AP_WCSOUT(ap)) {
+	    case WCS_WORLD, WCS_PHYSICAL:
+		call ap_ltoo (ap, wx, wy, AP_OXINIT(ctr), AP_OYINIT(ctr), 1)
+		call ap_ltoo (ap, wx, wy, AP_OXCENTER(ctr), AP_OYCENTER(ctr), 1)
+	    case WCS_TV:
+		call ap_ltov (im, wx, wy, AP_OXINIT(ctr), AP_OYINIT(ctr), 1)
+		call ap_ltov (im, wx, wy, AP_OXCENTER(ctr), AP_OYCENTER(ctr), 1)
+	    default:
+		AP_OXINIT(ctr) = wx
+		AP_OYINIT(ctr) = wy
+		AP_OXCENTER(ctr) = wx
+		AP_OYCENTER(ctr) = wy
+	    }
+	    return (AP_OK)
+	}
+
+	# Intialize.
+	owx = wx
+	owy = wy 
+	niter = 0
+	if (IS_INDEFR(AP_SKYSIGMA(nse)) || IS_INDEFR(AP_CTHRESHOLD(ctr)) ||
+	    AP_CTHRESHOLD(ctr) <= 0.0)
+	    cthreshold = 0.0
+	else
+	    cthreshold = AP_CTHRESHOLD(ctr) * AP_SKYSIGMA(nse) 
+
+	repeat {
+
+	    # Set initial cursor position.
+	    AP_CXCUR(ctr) = owx
+	    AP_CYCUR(ctr) = owy
+
+	    # Get centering pixels.
+	    ier = apctrbuf (ap, im, owx, owy)
+	    if (ier == AP_CTR_NOAREA) {
+	    	AP_XCENTER(ctr) = wx
+	    	AP_YCENTER(ctr) = wy
+	    	AP_XSHIFT(ctr) = 0.0
+	    	AP_YSHIFT(ctr) = 0.0
+	    	AP_XERR(ctr) = INDEFR
+	    	AP_YERR(ctr) = INDEFR
+	        switch (AP_WCSOUT(ap)) {
+	        case WCS_WORLD, WCS_PHYSICAL:
+		    call ap_ltoo (ap, wx, wy, AP_OXINIT(ctr), AP_OYINIT(ctr), 1)
+		    call ap_ltoo (ap, wx, wy, AP_OXCENTER(ctr),
+		        AP_OYCENTER(ctr), 1)
+	        case WCS_TV:
+		    call ap_ltov (im, wx, wy, AP_OXINIT(ctr), AP_OYINIT(ctr), 1)
+		    call ap_ltov (im, wx, wy, AP_OXCENTER(ctr),
+		        AP_OYCENTER(ctr), 1)
+	        default:
+		    AP_OXINIT(ctr) = wx
+		    AP_OYINIT(ctr) = wy
+		    AP_OXCENTER(ctr) = wx
+		    AP_OYCENTER(ctr) = wy
+	        }
+	    	AP_OXSHIFT(ctr) = 0.0
+	    	AP_OYSHIFT(ctr) = 0.0
+	    	return (ier)
+	    }
+
+	    # Clean the subraster.
+	    if (AP_CLEAN(ctr) == YES)
+	        call apclean (ap, Memr[AP_CTRPIX(ctr)], AP_CNX(ctr),
+		    AP_CNY(ctr), AP_CXC(ctr), AP_CYC(ctr))
+
+	    # Compute the datalimits.
+	    if (cthreshold <= 0.0)
+	        call alimr (Memr[AP_CTRPIX(ctr)], AP_CNX(ctr) * AP_CNY(ctr),
+		    datamin, datamax)
+	    else {
+		datamin = MAX_REAL
+		datamax = -MAX_REAL
+		do i = 1, AP_CNY(ctr) {
+		    med = amedr (Memr[AP_CTRPIX(ctr)+(i-1)*AP_CNX(ctr)],
+		        AP_CNX(ctr))
+		    if (med < datamin)
+			datamin = med
+		    if (med > datamax)
+			datamax = med
+		}
+	    }
+
+	    # Apply threshold and check for positive or negative features.
+	    if (AP_POSITIVE(ap) == YES) {
+		call apsetr (ap, CDATALIMIT, datamin)
+		call asubkr (Memr[AP_CTRPIX(ctr)], datamin +
+		    cthreshold, Memr[AP_CTRPIX(ctr)], AP_CNX(ctr) *
+		    AP_CNY(ctr))
+		call amaxkr (Memr[AP_CTRPIX(ctr)], 0.0, Memr[AP_CTRPIX(ctr)],
+		    AP_CNX(ctr) * AP_CNY(ctr))
+	    } else {
+		call apsetr (ap, CDATALIMIT, datamax)
+		call anegr (Memr[AP_CTRPIX(ctr)], Memr[AP_CTRPIX(ctr)],
+		    AP_CNX(ctr) * AP_CNY(ctr))
+		call aaddkr (Memr[AP_CTRPIX(ctr)], datamax -
+		    cthreshold, Memr[AP_CTRPIX(ctr)], AP_CNX(ctr) *
+		    AP_CNY(ctr))
+		call amaxkr (Memr[AP_CTRPIX(ctr)], 0.0,
+		    Memr[AP_CTRPIX(ctr)], AP_CNX(ctr) * AP_CNY(ctr))
+	    }
+
+	    # Test signal to noise ratio.
+	    if (ap_csnratio (ap, Memr[AP_CTRPIX(ctr)], AP_CNX(ctr),
+	        AP_CNY(ctr), 0.0) < AP_MINSNRATIO(ctr))
+	    	lowsnr = YES
+	    else
+		lowsnr = NO
+
+	    # Compute the x and y centers.
+	    switch (AP_CENTERFUNCTION(ctr)) {
+
+	    case AP_CENTROID1D:
+		if (AP_CTHRESHOLD(ctr) <= 0.0) {
+	            fier = ap_mctr1d (Memr[AP_CTRPIX(ctr)], AP_CNX(ctr),
+		        AP_CNY(ctr), AP_EPADU(nse), AP_XCENTER(ctr),
+			AP_YCENTER(ctr), AP_XERR(ctr), AP_YERR(ctr))
+		    if (IS_INDEFR (AP_XERR(ctr)))
+			AP_XCENTER(ctr) = AP_CXC(ctr)
+		    if (IS_INDEFR (AP_YERR(ctr)))
+			AP_YCENTER(ctr) = AP_CYC(ctr)
+		} else {
+	            fier = ap_ctr1d (Memr[AP_CTRPIX(ctr)], AP_CNX(ctr),
+		        AP_CNY(ctr), AP_EPADU(nse), AP_XCENTER(ctr),
+			AP_YCENTER(ctr), AP_XERR(ctr), AP_YERR(ctr))
+		    if (IS_INDEFR (AP_XERR(ctr)))
+			AP_XCENTER(ctr) = AP_CXC(ctr)
+		    if (IS_INDEFR (AP_YERR(ctr)))
+			AP_YCENTER(ctr) = AP_CYC(ctr)
+		}
+
+	    case AP_GAUSS1D:
+
+	        fier = ap_gctr1d (Memr[AP_CTRPIX(ctr)], AP_CNX(ctr),
+		    AP_CNY(ctr), CONVERT * AP_FWHMPSF(ap) * AP_SCALE(ap),
+		    AP_CMAXITER(ctr), AP_XCENTER(ctr), AP_YCENTER(ctr),
+		    AP_XERR(ctr), AP_YERR(ctr))
+
+	    case AP_OFILT1D:
+
+	        fier = ap_lgctr1d (Memr[AP_CTRPIX(ctr)], AP_CNX(ctr),
+		    AP_CNY(ctr), AP_CXC(ctr), AP_CYC(ctr), CONVERT *
+		    AP_FWHMPSF(ap) * AP_SCALE(ap), AP_CMAXITER(ctr),
+		    AP_EPADU(nse), AP_SKYSIGMA(nse), AP_XCENTER(ctr),
+		    AP_YCENTER(ctr), AP_XERR(ctr), AP_YERR(ctr))
+
+	    default:
+		# do nothing gracefully
+	    }
+
+	    # Confine the next x center to the data box.
+	    AP_XCENTER(ctr) = max (0.5, min (AP_CNX(ctr) + 0.5,
+	        AP_XCENTER(ctr)))
+	    xshift = AP_XCENTER(ctr) - AP_CXC(ctr)
+	    AP_XCENTER(ctr) = xshift + owx
+	    AP_XSHIFT(ctr) = AP_XCENTER(ctr) - wx
+
+	    # Confine the next y center to the data box.
+	    AP_YCENTER(ctr) = max (0.5, min (AP_CNY(ctr) + 0.5,
+	        AP_YCENTER(ctr)))
+	    yshift = AP_YCENTER(ctr) - AP_CYC(ctr)
+	    AP_YCENTER(ctr) = yshift + owy
+	    AP_YSHIFT(ctr) = AP_YCENTER(ctr) - wy
+
+	    switch (AP_WCSOUT(ap)) {
+	    case WCS_PHYSICAL, WCS_WORLD:
+		call ap_ltoo (ap, AP_XCENTER(ctr), AP_YCENTER(ctr),
+		    AP_OXCENTER(ctr), AP_OYCENTER(ctr), 1)
+		call ap_ltoo (ap, AP_XCENTER(ctr) - AP_XSHIFT(ctr),
+		    AP_YCENTER(ctr) - AP_YSHIFT(ctr), AP_OXINIT(ctr),
+		    AP_OYINIT(ctr), 1)
+		AP_OXSHIFT(ctr) = AP_OXCENTER(ctr) - AP_OXINIT(ctr)
+		AP_OYSHIFT(ctr) = AP_OYCENTER(ctr) - AP_OYINIT(ctr)
+	    case WCS_TV:
+		call ap_ltov (im, AP_XCENTER(ctr), AP_YCENTER(ctr),
+		    AP_OXCENTER(ctr), AP_OYCENTER(ctr), 1)
+		call ap_ltov (im, AP_XCENTER(ctr) - AP_XSHIFT(ctr),
+		    AP_YCENTER(ctr) - AP_YSHIFT(ctr), AP_OXINIT(ctr),
+		    AP_OYINIT(ctr), 1)
+		AP_OXSHIFT(ctr) = AP_OXCENTER(ctr) - AP_OXINIT(ctr)
+		AP_OYSHIFT(ctr) = AP_OYCENTER(ctr) - AP_OYINIT(ctr)
+	    default:
+		AP_OXINIT(ctr) = AP_XCENTER(ctr) - AP_XSHIFT(ctr)
+		AP_OYINIT(ctr) = AP_YCENTER(ctr) - AP_YSHIFT(ctr)
+		AP_OXCENTER(ctr) = AP_XCENTER(ctr)
+		AP_OYCENTER(ctr) = AP_YCENTER(ctr)
+		AP_OXSHIFT(ctr) = AP_XSHIFT(ctr)
+		AP_OYSHIFT(ctr) = AP_YSHIFT(ctr)
+		
+	    }
+
+	    # Setup for next iteration.
+	    niter = niter + 1
+	    owx = AP_XCENTER(ctr)
+	    owy = AP_YCENTER(ctr)
+
+	} until ((fier != AP_OK && fier != AP_CTR_NOCONVERGE) ||
+	    (niter >= AP_CMAXITER(ctr)) || (abs (xshift) < 1.0 &&
+	    abs (yshift) < 1.0))
+
+	# Return appropriate error code.
+	if (fier != AP_OK) {
+	    AP_XCENTER(ctr) = wx
+	    AP_YCENTER(ctr) = wy
+	    AP_XSHIFT(ctr) = 0.0
+	    AP_YSHIFT(ctr) = 0.0
+	    AP_XERR(ctr) = INDEFR
+	    AP_YERR(ctr) = INDEFR
+	    switch (AP_WCSOUT(ap)) {
+	    case WCS_WORLD, WCS_PHYSICAL:
+		call ap_ltoo (ap, wx, wy, AP_OXINIT(ctr), AP_OYINIT(ctr), 1)
+		call ap_ltoo (ap, wx, wy, AP_OXCENTER(ctr), AP_OYCENTER(ctr), 1)
+	    case WCS_TV:
+		call ap_ltov (im, wx, wy, AP_OXINIT(ctr), AP_OYINIT(ctr), 1)
+		call ap_ltov (im, wx, wy, AP_OXCENTER(ctr), AP_OYCENTER(ctr), 1)
+	    default:
+		AP_OXINIT(ctr) = wx
+		AP_OYINIT(ctr) = wy
+		AP_OXCENTER(ctr) = wx
+		AP_OYCENTER(ctr) = wy
+	    }
+	    AP_OXSHIFT(ctr) = 0.0
+	    AP_OYSHIFT(ctr) = 0.0
+	    return (fier)
+	} else if (ier == AP_CTR_BADDATA) {
+	    return (AP_CTR_BADDATA)
+	} else if (lowsnr == YES) {
+	    return (AP_CTR_LOWSNRATIO)
+	} else if (abs (AP_XSHIFT(ctr)) > (AP_MAXSHIFT(ctr) * AP_SCALE(ap))) {
+	    return (AP_CTR_BADSHIFT)
+	} else if (abs (AP_YSHIFT(ctr)) > (AP_MAXSHIFT(ctr) * AP_SCALE(ap))) {
+	    return (AP_CTR_BADSHIFT)
+	} else if (ier == AP_CTR_OUTOFBOUNDS) {
+	    return (AP_CTR_OUTOFBOUNDS)
+	} else {
+	    return (AP_OK)
+	}
+end
diff --git a/noao/digiphot/apphot/center/apgcpars.x b/noao/digiphot/apphot/center/apgcpars.x
new file mode 100644
index 00000000..e40db12e
--- /dev/null
+++ b/noao/digiphot/apphot/center/apgcpars.x
@@ -0,0 +1,27 @@
+include "../lib/display.h"
+include "../lib/noise.h"
+include "../lib/center.h"
+
+# AP_GCPARS -- Procedure to read in the centering parameters from the
+# appropriate parameters files.
+
+procedure ap_gcpars (ap)
+
+pointer	ap			# pointer to the apphot structure
+
+bool	clgetb()
+int	btoi()
+
+begin
+	# Initialize the structure.
+	call apcinit (ap, AP_CENTROID1D, 2.5, 2.0, AP_NPOISSON)
+
+	# Get the data dependent parameters.
+	call ap_gdapars (ap)
+
+	# Get the centering algorithm parameters.
+	call ap_gcepars (ap)
+
+	# Make radial plots on stdgraph.
+	call apseti (ap, RADPLOTS, btoi (clgetb ("radplots")))
+end
diff --git a/noao/digiphot/apphot/center/apgctr1d.x b/noao/digiphot/apphot/center/apgctr1d.x
new file mode 100644
index 00000000..e0ac8077
--- /dev/null
+++ b/noao/digiphot/apphot/center/apgctr1d.x
@@ -0,0 +1,105 @@
+include <math/nlfit.h>
+include "../lib/center.h"
+
+define	NPARS	4		# the total number of parameters
+define	NAPARS	3		# the total number of active parameters
+define	TOL	0.001		# the tolerance for convergence
+
+# AP_GCTR1D -- Procedure to compute the x and y centers from the 1D marginal
+# distributions using 1D Gaussian fits. Three parameters are fit for each
+# marginal, the amplitude, the center of the Gaussian function itself
+# and a constant background value. The sigma is set by the user and is
+# assumed to be fixed.
+
+int procedure ap_gctr1d (ctrpix, nx, ny, sigma, maxiter, xc, yc, xerr, yerr)
+
+real	ctrpix[nx, ny]		# data subarray
+int	nx, ny			# dimensions of data subarray
+real	sigma			# sigma of PSF
+int	maxiter			# maximum number of iterations
+real	xc, yc			# computed centers
+real	xerr, yerr		# estimate of centering error
+
+extern	cgauss1d, cdgauss1d
+int	i, minel, maxel, xier, yier, npar, npts
+pointer	sp, x, xm, ym, w, fit, list, nl
+real	chisqr, variance, p[NPARS], dp[NPARS]
+int	locpr()
+
+begin
+	# Check the number of points.
+	if (nx < NAPARS || ny < NAPARS)
+	    return (AP_CTR_NTOO_SMALL)
+	npts = max (nx, ny)
+
+	call smark (sp)
+	call salloc (list, NAPARS, TY_INT)
+	call salloc (xm, nx, TY_REAL)
+	call salloc (ym, ny, TY_REAL)
+	call salloc (x, npts, TY_REAL)
+	call salloc (w, npts, TY_REAL)
+	call salloc (fit, npts, TY_REAL)
+	do i = 1, npts
+	    Memr[x+i-1] = i
+
+	# Compute the marginal distributions.
+	call ap_mkmarg (ctrpix, Memr[xm], Memr[ym], nx, ny)
+	call adivkr (Memr[xm], real (nx), Memr[xm], nx)
+	call adivkr (Memr[ym], real (ny), Memr[ym], ny)
+
+	# Specify which parameters are to be fit.
+	Memi[list] = 1
+	Memi[list+1] = 2
+	Memi[list+2] = 4
+
+	# Initialize the x fit parameters.
+	call ap_alimr (Memr[xm], nx, p[4], p[1], minel, maxel)
+	p[1] = p[1] - p[4]
+	p[2] = maxel
+	p[3] = sigma ** 2
+
+	# Compute the x center and error.
+	call nlinitr (nl, locpr (cgauss1d), locpr (cdgauss1d), p, dp, NPARS,
+	    Memi[list], NAPARS, TOL, maxiter)
+	call nlfitr (nl, Memr[x], Memr[xm], Memr[w], nx, 1, WTS_UNIFORM, xier)
+	call nlvectorr (nl, Memr[x], Memr[fit], nx, 1)
+	call nlpgetr (nl, p, npar)
+	call nlerrorsr (nl, Memr[xm], Memr[fit], Memr[w], nx, variance,
+	    chisqr, dp)
+	call nlfreer (nl)
+	xc = p[2]
+	xerr = dp[2] / sqrt (real (nx))
+	if (xerr > real (nx))
+	    xerr = INDEFR
+
+	# Initialize the y fit parameters.
+	call ap_alimr (Memr[ym], ny, p[4], p[1], minel, maxel)
+	p[1] = p[1] - p[4]
+	p[2] = maxel
+	p[3] = sigma ** 2
+
+	# Fit the y marginal.
+	call nlinitr (nl, locpr (cgauss1d), locpr (cdgauss1d), p, dp, NPARS,
+	    Memi[list], NAPARS, TOL, maxiter)
+	call nlfitr (nl, Memr[x], Memr[ym], Memr[w], ny, 1, WTS_UNIFORM, yier)
+	call nlvectorr (nl, Memr[x], Memr[fit], ny, 1)
+	call nlpgetr (nl, p, npar)
+	call nlerrorsr (nl, Memr[ym], Memr[fit], Memr[w], ny, variance,
+	    chisqr, dp)
+	call nlfreer (nl)
+	yc = p[2]
+	yerr = dp[2] / sqrt (real (ny))
+	if (yerr > real (ny))
+	    yerr = INDEFR
+
+	# Return the appropriate error code.
+	call sfree (sp)
+	if (xier == NO_DEG_FREEDOM || yier == NO_DEG_FREEDOM)
+	    return (AP_CTR_NTOO_SMALL)
+	else if (xier == SINGULAR || yier == SINGULAR)
+	    return (AP_CTR_SINGULAR)
+	else if (xier == NOT_DONE || yier == NOT_DONE)
+	    return (AP_CTR_NOCONVERGE)
+	else
+	    return (AP_OK)
+end
diff --git a/noao/digiphot/apphot/center/apictr.x b/noao/digiphot/apphot/center/apictr.x
new file mode 100644
index 00000000..3a3bd31e
--- /dev/null
+++ b/noao/digiphot/apphot/center/apictr.x
@@ -0,0 +1,48 @@
+# AP_ICTR -- Given a subraster of pixels and an initial center compute
+# the centroid of the pixels.
+
+procedure ap_ictr (im, wx, wy, radius, emission, xcenter, ycenter)
+
+pointer	im		# pointer to the iraf image
+real	wx		# initial x coordinate
+real	wy		# initial y coordinate
+int	radius		# half width of centering box
+int	emission	# emission feature
+real	xcenter		# fitted x coordinate
+real	ycenter		# fitted y coordinate
+
+int	nx, ny, ier
+pointer	cbuf
+real	xc, yc, datamin, datamax, junk
+int	ap_mctr1d()
+pointer	ap_ctrpix()
+
+begin
+	# Get the pixels.
+	cbuf = ap_ctrpix (im, wx, wy, radius, xc, yc, nx, ny)
+	if (cbuf == NULL) {
+	    xcenter = wx
+	    ycenter = wy
+	    return
+	}
+
+	# Fit the center of the subraster.
+	call alimr (Memr[cbuf], nx * ny, datamin, datamax)
+	if (emission == YES)
+	    call asubkr (Memr[cbuf], datamin, Memr[cbuf], nx * ny)
+	else {
+	    call anegr (Memr[cbuf], Memr[cbuf], nx * ny)
+	    call aaddkr (Memr[cbuf], datamax, Memr[cbuf], nx * ny)
+	}
+	ier = ap_mctr1d (Memr[cbuf], nx, ny, 1.0, xcenter, ycenter, junk, junk)
+
+	# Compute the center in image coordinates.
+	if (IS_INDEFR(xcenter))
+	    xcenter = wx
+	else
+	    xcenter = xcenter + wx - xc
+	if (IS_INDEFR(ycenter))
+	    ycenter = wy
+	else
+	    ycenter = ycenter + wy - yc
+end
diff --git a/noao/digiphot/apphot/center/aplgctr1d.x b/noao/digiphot/apphot/center/aplgctr1d.x
new file mode 100644
index 00000000..ce6d7c53
--- /dev/null
+++ b/noao/digiphot/apphot/center/aplgctr1d.x
@@ -0,0 +1,87 @@
+include <math.h>
+include "../lib/center.h"
+
+define	TOL	0.001		# tolerance for fitting algorithm
+
+# AP_LGCTR1D -- Procedure to compute the center from the 1D marginal
+# distributions using a simplified version of the optimal filtering
+# technique and addopting a Gaussian model for the fit. The method
+# is streamlined by replacing the Gaussian with a simple triangle
+# following L.Goad.
+
+int procedure ap_lgctr1d (ctrpix, nx, ny, cx, cy, sigma, maxiter, norm,
+	skysigma, xc, yc, xerr, yerr)
+
+real	ctrpix[nx, ny]		# object to be centered
+int	nx, ny			# dimensions of subarray
+real	cx, cy			# center in subraster coordinates
+real	sigma			# sigma of PSF
+int	maxiter			# maximum number of iterations
+real	norm			# the normalization factor
+real	skysigma		# standard deviation of the pixels
+real	xc, yc			# computed centers
+real	xerr, yerr		# first guess at errors
+
+int	nxiter, nyiter
+pointer	sp, xm, ym
+real	ratio, constant
+
+int	aptopt()
+real	asumr()
+
+begin
+	# Allocate working space.
+	call smark (sp)
+	call salloc (xm, nx, TY_REAL)
+	call salloc (ym, ny, TY_REAL)
+
+	# Compute the marginal distributions.
+	call ap_mkmarg (ctrpix, Memr[xm], Memr[ym], nx, ny)
+	xerr = asumr (Memr[xm], nx)
+	yerr = asumr (Memr[ym], ny)
+	call adivkr (Memr[xm], real (nx), Memr[xm], nx)
+	call adivkr (Memr[ym], real (ny), Memr[ym], ny)
+
+	# Compute the x center and error.
+	xc = cx
+	nxiter = aptopt (Memr[xm], nx, xc, sigma, TOL, maxiter, YES)
+	if (xerr <= 0.0)
+	    xerr = INDEFR
+	else {
+	    if (IS_INDEFR(skysigma))
+	        constant = 0.0
+	    else
+	        constant = 4.0 * SQRTOFPI * sigma * skysigma ** 2 
+	    ratio = constant / xerr
+	    xerr = sigma ** 2 / (xerr * norm)
+	    xerr = sqrt (max (xerr, ratio * xerr))
+	    if (xerr > real (nx))
+		xerr = INDEFR
+	}
+
+	# Compute the y center and error.
+	yc = cy
+	nyiter = aptopt (Memr[ym], ny, yc, sigma, TOL, maxiter, YES)
+	if (yerr <= 0.0)
+	    yerr = INDEFR
+	else {
+	    if (IS_INDEFR(skysigma))
+	        constant = 0.0
+	    else
+	        constant = 4.0 * SQRTOFPI * sigma * skysigma ** 2 
+	    ratio = constant / yerr
+	    yerr = sigma ** 2 / (yerr * norm)
+	    yerr = sqrt (max (yerr, ratio * yerr))
+	    if (yerr > real (ny))
+		yerr = INDEFR
+	}
+
+	# Return appropriate error code.
+	call sfree (sp)
+	if (nxiter < 0 || nyiter < 0)
+	    return (AP_CTR_SINGULAR)
+	else if (nxiter > maxiter || nyiter > maxiter)
+	    return (AP_CTR_NOCONVERGE)
+	else
+	    return (AP_OK)
+end
diff --git a/noao/digiphot/apphot/center/apmctr1d.x b/noao/digiphot/apphot/center/apmctr1d.x
new file mode 100644
index 00000000..5dc47f60
--- /dev/null
+++ b/noao/digiphot/apphot/center/apmctr1d.x
@@ -0,0 +1,88 @@
+include <mach.h>
+include "../lib/center.h"
+
+# AP_MCTR1D -- Procedure to compute the center from the 1D marginal
+# distributions.
+
+int procedure ap_mctr1d (ctrpix, nx, ny, norm, xc, yc, xerr, yerr)
+
+real	ctrpix[nx, ny]		# object to be centered
+int	nx, ny			# dimensions of subarray
+real	norm			# the normalization factor
+real	xc, yc			# computed centers
+real	xerr, yerr		# estimate of centering error
+
+pointer	sp, xm, ym
+
+begin
+	call smark (sp)
+	call salloc (xm, nx, TY_REAL)
+	call salloc (ym, ny, TY_REAL)
+
+	# Compute the marginal distributions.
+	call ap_mkmarg (ctrpix, Memr[xm], Memr[ym], nx, ny)
+	call adivkr (Memr[xm], real (ny), Memr[xm], nx)
+	call adivkr (Memr[ym], real (nx), Memr[ym], ny)
+
+	# Get the centers and errors.
+	call ap_cmmarg (Memr[xm], nx, norm, xc, xerr)
+	call ap_cmmarg (Memr[ym], ny, norm, yc, yerr)
+
+	call sfree (sp)
+	return (AP_OK)
+end
+
+
+# AP_CMMARG -- Compute the center and estimate its error given the
+# marginal distribution and the number of points. The center is estimated
+# using a centroid which is an optimal solution for a gaussian star with
+# no background noise. The centering error is computing using a variance
+# estimate based on a gaussian star with no background noise.
+
+procedure ap_cmmarg (a, npts, norm, xc, err)
+
+real	a[npts]		# array
+int	npts		# number of points
+real	norm		# the normalization factor
+real	xc		# center value
+real	err		# error
+
+int	i, npos
+real	sumi, sumix, sumix2, mean, val
+real	asumr()
+
+begin
+	# Initialize.
+	mean = asumr (a, npts) / npts
+	npos = 0
+	sumi = 0.0
+	sumix = 0.0
+	sumix2 = 0.0
+
+	# Accumulate the sums.
+	do i = 1, npts {
+	    val = (a[i] - mean)
+	    if (val > 0.0) {
+		npos = npos + 1
+	        sumi = sumi + val
+	        sumix = sumix + val * i
+	        sumix2 = sumix2 + val * i ** 2
+	    }
+	}
+
+	# Compute the position and the error.
+	if (npos <= 0) {
+	    xc =  (1.0 + npts) / 2.0
+	    err = INDEFR
+	} else {
+	    xc = sumix / sumi
+	    err = (sumix2 / sumi - xc * xc)
+	    if (err <= 0.0) {
+		err = 0.0
+	    } else {
+	        err = sqrt (err / ((sumi + mean * npts) * norm))
+		if (err > real (npts))
+		    err = INDEFR
+	    }
+	}
+end
diff --git a/noao/digiphot/apphot/center/appcenter.x b/noao/digiphot/apphot/center/appcenter.x
new file mode 100644
index 00000000..c2590fa3
--- /dev/null
+++ b/noao/digiphot/apphot/center/appcenter.x
@@ -0,0 +1,84 @@
+include "../lib/apphot.h"
+include "../lib/center.h"
+
+# AP_PCENTER -- Procedure to write the output of centering task to a file.
+
+procedure ap_pcenter (ap, fd, id, lid, ier)
+
+pointer	ap	# pointer to apphot structure
+int	fd	# output file descriptor
+int	id	# id of the star
+int	lid	# list number
+int	ier	# comment string
+
+real	xpos, ypos
+real	apstatr()
+
+begin
+	if (fd == NULL)
+	    return
+
+	# Print description of object.
+	xpos = apstatr (ap, OXINIT)
+	ypos = apstatr (ap, OYINIT)
+	call ap_wid (ap, fd, xpos, ypos, id, lid, '\\')
+
+	# Print the computed centers.
+	call ap_wcres (ap, fd, ier, ' ')
+end
+
+
+# AP_QCENTER -- Procedure to print a quick summary of the center task output
+# on the standard output.
+
+procedure ap_qcenter (ap, ier)
+
+pointer	ap	# pointer to apphot structure
+int	ier	# comment string
+
+real	owx, owy, wx, wy
+pointer	sp, imname
+real	apstatr()
+
+begin
+	call smark (sp)
+	call salloc (imname, SZ_FNAME, TY_CHAR)
+
+	owx = apstatr (ap, OXINIT)
+	owy = apstatr (ap, OYINIT)
+	wx = apstatr (ap, OXCENTER)
+	wy = apstatr (ap, OYCENTER)
+
+	call apstats (ap, IMROOT, Memc[imname], SZ_FNAME)
+	call printf ( "%s  %7.2f %7.2f  %7.2f %7.2f  ")
+	    call pargstr (Memc[imname])
+	    call pargr (owx)
+	    call pargr (owy)
+	    call pargr (wx)
+	    call pargr (wy)
+	call printf ("%6.2f %6.2f  %s\n")
+	    call pargr (apstatr (ap, XERR))
+	    call pargr (apstatr (ap, YERR))
+	    if (ier != AP_OK)
+		call pargstr ("err")
+	    else
+		call pargstr ("ok")
+
+	call sfree (sp)
+end
+
+
+# AP_CPHDR -- Procedure to write the banner for the center task to the
+# output file.
+
+procedure ap_cphdr (ap, fd)
+
+pointer	ap		# apphot descriptor
+int	fd		# output file descriptor
+
+begin
+	if (fd == NULL)
+	    return
+	call ap_idhdr (ap, fd)
+	call ap_chdr (ap, fd)
+end
diff --git a/noao/digiphot/apphot/center/appcpars.x b/noao/digiphot/apphot/center/appcpars.x
new file mode 100644
index 00000000..272fcc07
--- /dev/null
+++ b/noao/digiphot/apphot/center/appcpars.x
@@ -0,0 +1,21 @@
+include "../lib/display.h"
+
+# AP_PCPARS -- Procedure to write out the current centering parameters
+# to the current parameter files.
+
+procedure ap_pcpars (ap)
+
+pointer	ap		# pointer to apphot structure
+bool	itob()
+int	apstati()
+
+begin
+	# Write the data dependent parameters.
+	call ap_dapars (ap)
+
+	# Write the centering parameters.
+	call ap_cepars (ap)
+
+	# Set the plotting command.
+	call clputb ("radplots", itob (apstati (ap, RADPLOTS)))
+end
diff --git a/noao/digiphot/apphot/center/aprefitcen.x b/noao/digiphot/apphot/center/aprefitcen.x
new file mode 100644
index 00000000..c50e2efb
--- /dev/null
+++ b/noao/digiphot/apphot/center/aprefitcen.x
@@ -0,0 +1,193 @@
+include <mach.h>
+include "../lib/apphotdef.h"
+include "../lib/apphot.h"
+include "../lib/noisedef.h"
+include "../lib/centerdef.h"
+include "../lib/center.h"
+
+define	CONVERT	.424660900	# conversion factor from fwhmpsf to sigma
+
+# APREFITCENTER -- Procedure to refit the centers assuming that the appropriate
+# pixel buffer is in memory. See apfitcenter for further information.
+
+int procedure aprefitcenter (ap, im, ier)
+
+pointer	ap		# pointer to the apphot structure
+pointer	im		# the input image descriptor
+int	ier		# previous error code
+
+int	fier
+pointer	cen, nse
+int	ap_ctr1d(), ap_mctr1d(), ap_gctr1d(), ap_lgctr1d()
+
+begin
+	cen = AP_PCENTER(ap)
+	nse = AP_NOISE(ap)
+
+	# Initialize
+        AP_XCENTER(cen) = AP_CXCUR(cen)
+	AP_YCENTER(cen) = AP_CYCUR(cen)
+	AP_XSHIFT(cen) = 0.0
+	AP_YSHIFT(cen) = 0.0
+	AP_OXSHIFT(cen) = 0.0
+	AP_OYSHIFT(cen) = 0.0
+	AP_XERR(cen) = INDEFR
+	AP_YERR(cen) = INDEFR
+
+	# Return if the center is undefined.
+	if (IS_INDEFR(AP_CXCUR(cen)) || IS_INDEFR(AP_CYCUR(cen))) {
+	    AP_OXINIT(cen) = INDEFR
+	    AP_OYINIT(cen) = INDEFR
+            AP_OXCENTER(cen) = INDEFR
+	    AP_OYCENTER(cen) = INDEFR
+	    return (AP_CTR_NOAREA)
+	}
+
+	# Convert the coordinates.
+	switch (AP_WCSOUT(ap)) {
+        case WCS_WORLD, WCS_PHYSICAL:
+            call ap_ltoo (ap, AP_CXCUR(cen), AP_CYCUR(cen), AP_OXINIT(cen),
+		AP_OYINIT(cen), 1)
+            call ap_ltoo (ap, AP_CXCUR(cen), AP_CYCUR(cen), AP_OXCENTER(cen),
+		AP_OYCENTER(cen), 1)
+        case WCS_TV:
+            call ap_ltov (im, AP_CXCUR(cen), AP_CYCUR(cen), AP_OXINIT(cen),
+		AP_OYINIT(cen), 1)
+            call ap_ltov (im, AP_CXCUR(cen), AP_CYCUR(cen), AP_OXCENTER(cen),
+		AP_OYCENTER(cen), 1)
+        default:
+	    AP_OXINIT(cen) = AP_CXCUR(cen)
+	    AP_OYINIT(cen) = AP_CYCUR(cen)
+            AP_OXCENTER(cen) = AP_CXCUR(cen)
+	    AP_OYCENTER(cen) = AP_CYCUR(cen)
+        }
+
+	# Return input coordinates if no center fitting.
+	if (AP_CENTERFUNCTION(cen) == AP_NONE)
+	    return (AP_OK)
+
+	# Choose the centering algorithm.
+	switch (AP_CENTERFUNCTION(cen)) {
+
+	case AP_CENTROID1D:
+
+	    # Compute the x and y centroids.
+	    if (AP_CTHRESHOLD(cen) <= 0.0) {
+	        fier = ap_mctr1d (Memr[AP_CTRPIX(cen)], AP_CNX(cen),
+		    AP_CNY(cen), AP_EPADU(nse), AP_XCENTER(cen),
+		    AP_YCENTER(cen), AP_XERR(cen), AP_YERR(cen))
+		if (IS_INDEFR(AP_XERR(cen)))
+		    AP_XCENTER(cen) = AP_CXC(cen)
+		if (IS_INDEFR(AP_YERR(cen)))
+		    AP_YCENTER(cen) = AP_CYC(cen)
+	    } else {
+	        fier = ap_ctr1d (Memr[AP_CTRPIX(cen)], AP_CNX(cen),
+		    AP_CNY(cen), AP_EPADU(nse), AP_XCENTER(cen),
+		    AP_YCENTER(cen), AP_XERR(cen), AP_YERR(cen))
+		if (IS_INDEFR(AP_XERR(cen)))
+		    AP_XCENTER(cen) = AP_CXC(cen)
+		if (IS_INDEFR(AP_YERR(cen)))
+		    AP_YCENTER(cen) = AP_CYC(cen)
+	    }
+	    AP_XCENTER(cen) = AP_XCENTER(cen) + AP_CXCUR(cen) - AP_CXC(cen)
+	    AP_YCENTER(cen) = AP_YCENTER(cen) + AP_CYCUR(cen) - AP_CYC(cen)
+	    AP_XSHIFT(cen) = AP_XCENTER(cen) - AP_CXCUR(cen)
+	    AP_YSHIFT(cen) = AP_YCENTER(cen) - AP_CYCUR(cen)
+
+	case AP_GAUSS1D:
+
+	    # Compute the 1D Gaussian x and y centers.
+	    fier = ap_gctr1d (Memr[AP_CTRPIX(cen)], AP_CNX(cen), AP_CNY(cen),
+		CONVERT * AP_FWHMPSF(ap) * AP_SCALE(ap), AP_CMAXITER(cen),
+		AP_XCENTER(cen), AP_YCENTER(cen), AP_XERR(cen), AP_YERR(cen))
+	    AP_XCENTER(cen) = AP_XCENTER(cen) + AP_CXCUR(cen) - AP_CXC(cen)
+	    AP_YCENTER(cen) = AP_YCENTER(cen) + AP_CYCUR(cen) - AP_CYC(cen)
+	    AP_XSHIFT(cen) = AP_XCENTER(cen) - AP_CXCUR(cen)
+	    AP_YSHIFT(cen) = AP_YCENTER(cen) - AP_CYCUR(cen)
+
+	case AP_OFILT1D:
+
+	    # Compute the Goad 1D x and y centers.
+	    fier = ap_lgctr1d (Memr[AP_CTRPIX(cen)], AP_CNX(cen), AP_CNY(cen),
+		 AP_CXC(cen), AP_CYC(cen), CONVERT * AP_FWHMPSF(ap) *
+		 AP_SCALE(ap), AP_CMAXITER(cen), AP_EPADU(nse),
+		 AP_SKYSIGMA(nse), AP_XCENTER(cen), AP_YCENTER(cen),
+		 AP_XERR(cen), AP_YERR(cen))
+	    AP_XCENTER(cen) = AP_XCENTER(cen) + AP_CXCUR(cen) - AP_CXC(cen)
+	    AP_YCENTER(cen) = AP_YCENTER(cen) + AP_CYCUR(cen) - AP_CYC(cen)
+	    AP_XSHIFT(cen) = AP_XCENTER(cen) - AP_CXCUR(cen)
+	    AP_YSHIFT(cen) = AP_YCENTER(cen) - AP_CYCUR(cen)
+
+	default:
+
+	    # do nothing gracefully
+        }
+
+	# Convert the coordinates.
+        switch (AP_WCSOUT(ap)) {
+        case WCS_WORLD, WCS_PHYSICAL:
+            call ap_ltoo (ap, AP_XCENTER(cen), AP_YCENTER(cen),
+                AP_OXCENTER(cen), AP_OYCENTER(cen), 1)
+            call ap_ltoo (ap, AP_XCENTER(cen) - AP_XSHIFT(cen),
+                AP_YCENTER(cen) - AP_YSHIFT(cen), AP_OXINIT(cen),
+                AP_OYINIT(cen), 1)
+            AP_OXSHIFT(cen) = AP_OXCENTER(cen) - AP_OXINIT(cen)
+            AP_OYSHIFT(cen) = AP_OYCENTER(cen) - AP_OYINIT(cen)
+        case WCS_TV:
+            call ap_ltov (im, AP_XCENTER(cen), AP_YCENTER(cen),
+                AP_OXCENTER(cen), AP_OYCENTER(cen), 1)
+            call ap_ltov (im, AP_XCENTER(cen) - AP_XSHIFT(cen),
+                AP_YCENTER(cen) - AP_YSHIFT(cen), AP_OXINIT(cen),
+                AP_OYINIT(cen), 1)
+            AP_OXSHIFT(cen) = AP_OXCENTER(cen) - AP_OXINIT(cen)
+            AP_OYSHIFT(cen) = AP_OYCENTER(cen) - AP_OYINIT(cen)
+        default:
+	    AP_OXCENTER(cen) = AP_XCENTER(cen)
+	    AP_OYCENTER(cen) = AP_YCENTER(cen)
+	    AP_OXINIT(cen) = AP_XCENTER(cen) - AP_XSHIFT(cen)
+	    AP_OYINIT(cen) = AP_YCENTER(cen) - AP_YSHIFT(cen)
+	    AP_OXSHIFT(cen) = AP_XSHIFT(cen)
+	    AP_OYSHIFT(cen) = AP_YSHIFT(cen)
+        }
+
+	# Return appropriate error code.
+	if (fier != AP_OK) {
+	    AP_XCENTER(cen) = AP_CXCUR(cen)
+	    AP_YCENTER(cen) = AP_CYCUR(cen)
+	    AP_XSHIFT(cen) = 0.0
+	    AP_YSHIFT(cen) = 0.0
+	    AP_XERR(cen) = INDEFR
+	    AP_YERR(cen) = INDEFR
+	    switch (AP_WCSOUT(ap)) {
+            case WCS_WORLD, WCS_PHYSICAL:
+                call ap_ltoo (ap, AP_CXCUR(cen), AP_CYCUR(cen), AP_OXINIT(cen),
+		    AP_OYINIT(cen), 1)
+                call ap_ltoo (ap, AP_CXCUR(cen), AP_CYCUR(cen),
+		    AP_OXCENTER(cen), AP_OYCENTER(cen), 1)
+            case WCS_TV:
+                call ap_ltov (im, AP_CXCUR(cen), AP_CYCUR(cen), AP_OXINIT(cen),
+		    AP_OYINIT(cen), 1)
+                call ap_ltov (im, AP_CXCUR(cen), AP_CYCUR(cen),
+		    AP_OXCENTER(cen), AP_OYCENTER(cen), 1)
+            default:
+	        AP_OXCENTER(cen) = AP_CXCUR(cen)
+	        AP_OYCENTER(cen) = AP_CYCUR(cen)
+	        AP_OXINIT(cen) = AP_CXCUR(cen)
+	        AP_OYINIT(cen) = AP_CYCUR(cen)
+            }
+            AP_OXSHIFT(cen) = 0.0
+            AP_OYSHIFT(cen) = 0.0
+	    return (fier)
+	} else if (ier == AP_CTR_BADDATA) {
+	    return (AP_CTR_BADDATA)
+	} else if (ier == AP_CTR_LOWSNRATIO) {
+	    return (AP_CTR_LOWSNRATIO)
+	} else if (abs (AP_XSHIFT(cen)) > (AP_MAXSHIFT(cen) * AP_SCALE(ap))) {
+	    return (AP_CTR_BADSHIFT)
+	} else if (abs (AP_YSHIFT(cen)) > (AP_MAXSHIFT(cen) * AP_SCALE(ap))) {
+	    return (AP_CTR_BADSHIFT)
+	} else if (ier == AP_CTR_OUTOFBOUNDS) {
+	    return (AP_CTR_OUTOFBOUNDS)
+	} else
+	    return (AP_OK)
+end
diff --git a/noao/digiphot/apphot/center/center.key b/noao/digiphot/apphot/center/center.key
new file mode 100644
index 00000000..f71cd8d3
--- /dev/null
+++ b/noao/digiphot/apphot/center/center.key
@@ -0,0 +1,78 @@
+	Interactive Keystroke Commands
+
+?	Print help
+:	Colon commands
+v	Verify the critical parameters
+w	Save the current parameters
+d	Plot radial profile of current star
+i	Interactively set parameters using current star
+f	Fit center of current star
+spbar	Fit center of current star, output results
+m	Move to next star in coordinate list
+n	Center next star in coordinate list, output results
+l	Center remaining stars in coordinate list, output results
+e	Print error messages
+r	Rewind the coordinate list
+q	Exit task
+
+
+	Colon Commands
+
+:show	[data/center]	List the parameters
+:m [n]	Move to next [nth] star in coordinate list
+:n [n]	Center next [nth] star in coordinate list, output results
+
+
+	Colon Parameter Editing Commands
+
+# Image and file name parameters
+
+:image		[string]	Image name
+:coords		[string]	Coordinate file name
+:output 	[string]	Output file name
+
+# Data dependent parameters
+
+:scale		[value]		Image scale (units per pixel)
+:fwhmpsf	[value]		Full-width half-maximum of PSF (scale units)
+:emission	[y/n]		Emission feature (y), absorption (n)
+:sigma		[value]		Standard deviation of sky (counts)
+:datamin	[value]		Minimum good data value (counts)
+:datamax	[value]		Maximum good data value (counts)
+
+# Noise parameters
+
+:noise 		[string]	Noise model (constant|poisson)
+:gain		[string]	Gain image header keyword
+:ccdread	[string]	Readout noise image header keyword
+:epadu		[value]		Gain (electrons per adu)
+:readnoise	[value]		Readout noise (electrons)
+
+# Observations parameters
+
+:exposure	[string]	Exposure time image header keyword
+:airmass	[string]	Airmass image header keyword
+:filter		[string]	Filter image header keyword
+:obstime	[string]	Time of observation image header keyword
+:itime		[value]		Exposure time (time units)
+:xairmass	[value]		Airmass value (number)
+:ifilter	[string]	Filter id string
+:otime		[string]	Time of observation (time units)
+
+# Centering parameters 
+
+:calgorithm	[string]	Centering algorithm
+:cbox		[value]		Width of centering box (scale units)
+:cthreshold	[value]		Centering intensity threshold (sigma)
+:cmaxiter	[value]		Maximum number of iterations
+:maxshift	[value]		Maximum center shift (scale units)
+:minsnratio	[value]		Minimum signal to noise for centering
+:clean		[y/n]		Clean subraster before centering
+:rclean		[value]		Cleaning radius (scale units)
+:rclip		[value]		Clipping radius (scale units)
+:kclean		[value]		Clean K-sigma rejection limit (sigma)
+
+# Plotting and marking parameters
+
+:mkcenter	[y/n]		Mark computed centers on the display
+:radplot	[y/n]		Plot radial profile of object
diff --git a/noao/digiphot/apphot/center/icenter.key b/noao/digiphot/apphot/center/icenter.key
new file mode 100644
index 00000000..0e5379f0
--- /dev/null
+++ b/noao/digiphot/apphot/center/icenter.key
@@ -0,0 +1,12 @@
+                    Interactive Center Setup Menu
+
+	v	Mark and verify the critical center parameters (f,s,c)
+
+	f	Mark and verify the full-width half-maximum of the psf
+	s	Mark and verify the standard deviation of the background
+	l	Mark and verify the minimum good data value
+	u	Mark and verify the maximum good data value
+
+	c	Mark and verify the centering box half-width
+	n	Mark and verify the cleaning radius
+	p	Mark and verify the clipping radius
diff --git a/noao/digiphot/apphot/center/mkpkg b/noao/digiphot/apphot/center/mkpkg
new file mode 100644
index 00000000..dde81929
--- /dev/null
+++ b/noao/digiphot/apphot/center/mkpkg
@@ -0,0 +1,54 @@
+# CENTER task
+
+$checkout libpkg.a ".."
+$update libpkg.a
+$checkin libpkg.a ".."
+$exit
+
+libpkg.a:
+	apbcenter.x	../lib/apphot.h		../lib/display.h	\
+			<fset.h>
+	apcconfirm.x	../lib/apphot.h		../lib/noise.h          \
+			../lib/center.h
+	apcencolon.x	../lib/apphot.h		../lib/center.h         \
+			../lib/display.h	../lib/noise.h
+	apcenter.x	../lib/apphot.h		../lib/center.h		\
+			../lib/display.h	<ctype.h>		\
+			<gset.h>                <imhdr.h>
+	apcerrors.x	../lib/center.h
+	apcfree.x	../lib/apphotdef.h	../lib/centerdef.h
+	apictr.x
+	apcinit.x	../lib/apphotdef.h	../lib/center.h		\
+			../lib/centerdef.h
+	apclean.x	../lib/apphot.h		../lib/center.h		\
+			../lib/noise.h
+	appcpars.x	../lib/display.h
+	apcplot.x	../lib/apphot.h		../lib/apphotdef.h	\
+			../lib/center.h		../lib/centerdef.h	\
+			../lib/noise.h		<gset.h>		\
+			<pkg/gtools.h>		<mach.h>
+	apcpshow.x	../lib/center.h		../lib/display.h
+	apcshow.x	../lib/display.h
+	apcsnratio.x	../lib/center.h		../lib/noise.h          \
+			<mach.h>
+	apctr1d.x	../lib/center.h		<mach.h>
+	apctrbuf.x	../lib/apphotdef.h	../lib/center.h         \
+			../lib/centerdef.h	<imhdr.h> <math.h>      \
+			<mach.h>
+	apmctr1d.x	../lib/center.h		<mach.h>
+	apfitcen.x	../lib/apphotdef.h	../lib/center.h         \
+			../lib/centerdef.h	../lib/noisedef.h	\
+			../lib/apphot.h         <mach.h>
+	apgcpars.x	../lib/center.h		../lib/display.h        \
+			../lib/noise.h
+	apgctr1d.x	../lib/center.h		<math/nlfit.h>
+	aplgctr1d.x	../lib/center.h		<math.h>
+	appcenter.x	../lib/apphot.h		../lib/center.h
+	apcradsetup.x	../lib/display.h
+	aprefitcen.x	../lib/apphotdef.h	../lib/center.h         \
+			../lib/centerdef.h	../lib/noisedef.h	\
+			../lib/apphot.h         <mach.h>
+	t_center.x	../lib/apphot.h		../lib/noise.h          \
+			<fset.h>		<gset.h>                \
+			<imhdr.h>
+	;
diff --git a/noao/digiphot/apphot/center/t_center.x b/noao/digiphot/apphot/center/t_center.x
new file mode 100644
index 00000000..456b93d2
--- /dev/null
+++ b/noao/digiphot/apphot/center/t_center.x
@@ -0,0 +1,306 @@
+include <fset.h>
+include <gset.h>
+include <imhdr.h>
+include "../lib/apphot.h"
+include "../lib/noise.h"
+
+# T_CENTER -- Procedure to compute accurate centers for a list of objects
+# given a list of starting centers, a set of starting parameters and a list
+# of images.
+
+procedure t_center ()
+
+pointer	image	               	# pointer to name of the image
+pointer	output	 		# pointer to output file name
+pointer	coords			# pointer to coordinate file
+pointer plotfile		# name of plot metacode file
+pointer	graphics		# pointer to graphics device
+pointer display			# pointer to display device
+int	interactive		# interactive mode
+int	cache			# cache image buffer in memory
+int	verify			# verify parameters
+int	update			# update parameters
+int	verbose			# verbose mode
+
+pointer	sp, str, cname, outfname, ap, im, id, gd, mgd
+int	limlist, lclist, lolist, sid, lid, cl, pfd, out, root, stat, memstat
+int	imlist, clist, olist, wcs, req_size, old_size, buf_size
+
+pointer	immap(), gopen()
+int	imtlen(), imtgetim(), clplen(), clgfil(), btoi(), fnldir(), strncmp()
+int	open(), strlen(), apcenter(), imtopenp(), clpopnu(), clgwrd()
+int	ap_memstat(), sizeof()
+bool	clgetb(), streq()
+errchk	gopen
+
+begin
+	# Allocate working space.
+	call smark (sp)
+	call salloc (image, SZ_FNAME, TY_CHAR)
+	call salloc (output, SZ_FNAME, TY_CHAR)
+	call salloc (coords, SZ_FNAME, TY_CHAR)
+	call salloc (plotfile, SZ_FNAME, TY_CHAR)
+	call salloc (graphics, SZ_FNAME, TY_CHAR)
+	call salloc (display, SZ_FNAME, TY_CHAR)
+	call salloc (outfname, SZ_FNAME, TY_CHAR)
+	call salloc (cname, SZ_FNAME, TY_CHAR)
+	call salloc (str, SZ_LINE, TY_CHAR)
+
+	# Set standard output to flush on newline.
+	call fseti (STDOUT, F_FLUSHNL, YES)
+
+	# Get input and output file names.
+	imlist = imtopenp ("image")
+	limlist = imtlen (imlist)
+	clist = clpopnu ("coords") 
+	lclist = clplen (clist)
+	olist = clpopnu ("output")
+	lolist = clplen (olist)
+
+	# Check that image and coordinate list lengths match.
+	if (limlist < 1 || (lclist > 1 && lclist != limlist)) {
+	    call imtclose (imlist)
+	    call clpcls (clist)
+	    call clpcls (olist)
+	    call error (0, "Imcompatible image and coordinate list lengths")
+	}
+
+	# Check that image and output list lengths match.
+	if (lolist > 1 && lolist != limlist) {
+	    call imtclose (imlist)
+	    call clpcls (clist)
+	    call clpcls (olist)
+	    call error (0, "Imcompatible image and output list lengths")
+	}
+
+	call clgstr ("icommands.p_filename", Memc[cname], SZ_FNAME)
+	if (Memc[cname] != EOS)
+	    interactive = NO
+	#else if (lclist == 0)
+	    #interactive = YES
+	else
+	    interactive = btoi (clgetb ("interactive"))
+	cache = btoi (clgetb ("cache"))
+	verbose = btoi (clgetb ("verbose"))
+	verify = btoi (clgetb ("verify"))
+	update = btoi (clgetb ("update"))
+
+	# Get the centering parameters.
+	call ap_gcpars (ap)
+
+	# confirm the centering algorithm parameters.
+	if (verify == YES && interactive == NO) {
+	    call ap_cconfirm (ap, NULL, 1)
+	    if (update == YES)
+		call ap_pcpars (ap)
+	}
+
+	# Get the wcs information.
+        wcs = clgwrd ("wcsin", Memc[str], SZ_LINE, WCSINSTR)
+        if (wcs <= 0) {
+	    call eprintf (
+	        "Warning: Setting the input coordinate system to logical\n")
+            wcs = WCS_LOGICAL
+	}
+        call apseti (ap, WCSIN, wcs)
+        wcs = clgwrd ("wcsout", Memc[str], SZ_LINE, WCSOUTSTR)
+        if (wcs <= 0) {
+	    call eprintf (
+	        "Warning: Setting the output coordinate system to logical\n")
+            wcs = WCS_LOGICAL
+	}
+        call apseti (ap, WCSOUT, wcs)
+	
+	# Get the graphics and display devices.
+	call clgstr ("graphics", Memc[graphics], SZ_FNAME)
+	call clgstr ("display", Memc[display], SZ_FNAME)
+
+	# Open the graphics and image deisplay devices.
+	if (interactive == YES) {
+	    if (Memc[graphics] == EOS)
+		gd = NULL
+	    else {
+		iferr {
+		    gd =  gopen (Memc[graphics], APPEND+AW_DEFER, STDGRAPH)
+		} then {
+		    call eprintf (
+			"Warning: Error opening the graphics device.\n")
+		    gd = NULL
+		}
+	    }
+	    if (Memc[display] == EOS)
+		id = NULL
+	    else if (streq (Memc[graphics], Memc[display]))
+		id = gd
+	    else {
+		iferr {
+		    id = gopen (Memc[display], APPEND, STDIMAGE)
+		} then {
+		    call eprintf (
+		"Warning: Graphics overlay not available for display device.\n")
+		    id = NULL
+		}
+	    }
+	} else {
+	    gd = NULL
+	    id = NULL
+	}
+
+	# Open the plot metacode file.
+	call clgstr ("plotfile", Memc[plotfile], SZ_FNAME)
+	if (Memc[plotfile] == EOS)
+	    pfd = NULL
+	else
+	    pfd = open (Memc[plotfile], APPEND, BINARY_FILE)
+	if (pfd != NULL)
+	    mgd = gopen (Memc[graphics], NEW_FILE, pfd)
+	else
+	    mgd = NULL
+
+	# Begin looping over the image list.
+	sid = 1
+	while (imtgetim (imlist, Memc[image], SZ_FNAME) != EOF) {
+
+	    # Open image.
+	    im = immap (Memc[image], READ_ONLY, 0)
+	    call apimkeys (ap, im, Memc[image])
+
+	    # Set the image display viewport. 
+	    if ((id != NULL) && (id != gd))
+		call ap_gswv (id, Memc[image], im, 4)
+
+	    # Cache the input image pixels.
+	    req_size = MEMFUDGE * IM_LEN(im,1) * IM_LEN(im,2) *
+	        sizeof (IM_PIXTYPE(im))
+	    memstat = ap_memstat (cache, req_size, old_size)
+	    if (memstat == YES)
+		call ap_pcache (im, INDEFI, buf_size)
+
+	    # Open the coordinate file; where coords is assumed to be a simple
+	    # text file in which the x and y positions are in columns 1 and 2
+	    # respectively and all remaining fields are ignored.
+
+	    if (lclist <= 0) {
+		cl = NULL
+		call strcpy ("", Memc[outfname], SZ_FNAME)
+	    } else {
+		stat = clgfil (clist, Memc[coords], SZ_FNAME)
+		root = fnldir (Memc[coords], Memc[outfname], SZ_FNAME)
+		if (strncmp ("default", Memc[coords+root], 7) == 0 || root ==
+		    strlen (Memc[coords])) {
+		    call ap_inname (Memc[image], Memc[outfname], "coo",
+		        Memc[outfname], SZ_FNAME)
+		    lclist = limlist
+	            cl = open (Memc[outfname], READ_ONLY, TEXT_FILE)
+		} else if (stat != EOF) {
+		    call strcpy (Memc[coords], Memc[outfname], SZ_FNAME)
+	            cl = open (Memc[outfname], READ_ONLY, TEXT_FILE)
+		} else { 
+		    call apstats (ap, CLNAME, Memc[outfname], SZ_FNAME)
+		    call seek (cl, BOF)
+		}
+	    }
+	    call apsets (ap, CLNAME, Memc[outfname])
+	    call apfroot (Memc[outfname], Memc[str], SZ_LINE)
+	    call apsets (ap, CLROOT, Memc[str])
+
+	    # Open output text file; if output is "default", dir$default  or
+	    # a directory specification then the extension "ctr" is added to
+	    # the root image name and a suitable version number is appended to
+	    # the output name. If the output string is null then no output
+	    # file is created.
+
+	    if (lolist == 0) {
+		out = NULL
+		call strcpy ("", Memc[outfname], SZ_FNAME)
+	    } else {
+	        stat = clgfil (olist, Memc[output], SZ_FNAME)
+		root = fnldir (Memc[output], Memc[outfname], SZ_FNAME)
+		if (strncmp ("default", Memc[output+root], 7) == 0 || root == 
+		    strlen (Memc[output])) {
+	            call apoutname (Memc[image], Memc[outfname], "ctr",
+		        Memc[outfname], SZ_FNAME)
+	            out = open (Memc[outfname], NEW_FILE, TEXT_FILE)
+		    lolist = limlist
+		} else if (stat != EOF) {
+		    call strcpy (Memc[output], Memc[outfname], SZ_FNAME)
+	            out = open (Memc[outfname], NEW_FILE, TEXT_FILE)
+		} else
+		    call apstats (ap, OUTNAME, Memc[outfname], SZ_FNAME)
+	    }
+	    call apsets (ap, OUTNAME, Memc[outfname])
+
+	    # Fit the centers.
+	    if (interactive == NO) {
+	        if (Memc[cname] != EOS)
+		    stat = apcenter (ap, im, cl, NULL, mgd, NULL, out, sid,
+		        NO, cache)
+	        else if (cl != NULL) {
+		    lid = 1
+	            call apbcenter (ap, im, cl, out, sid, lid, mgd, id,
+		        verbose)
+		    stat = NO
+		} else
+		    stat = NO
+	    } else
+	        stat = apcenter (ap, im, cl, gd, mgd, id, out, sid, YES, cache)
+
+	    # Close up image, coordinates, and output file.
+	    call imunmap (im)
+	    if (cl != NULL) {
+		if (lclist > 1)
+	            call close (cl)
+	    }
+	    if (out != NULL && lolist != 1) {
+		call close (out)
+		if (sid <= 1) {
+		    call apstats (ap, OUTNAME, Memc[outfname], SZ_FNAME)
+		    call delete (Memc[outfname])
+		}
+		sid = 1
+	    }
+
+	    # Uncache memory.
+	    call fixmem (old_size)
+
+	    if (stat == YES)
+		break
+
+	}
+
+	# If only one coordinate file for a list of images close it.
+	if (cl != NULL && lclist == 1)
+	    call close (cl)
+
+	# If only one output file defined for a list of images close it.
+	if (out != NULL && lolist == 1) {
+	    call close (out)
+	    if (sid <= 1) {
+		call apstats (ap, OUTNAME, Memc[outfname], SZ_FNAME)
+		call delete (Memc[outfname])
+	    }
+	}
+
+	# Close up graphics and image display streams and the plot files.
+	if (id == gd && id != NULL)
+	    call gclose (gd)
+	else {
+	    if (gd != NULL)
+	        call gclose (gd)
+	    if (id != NULL)
+		call gclose (id)
+	}
+	if (mgd != NULL)
+	    call gclose (mgd)
+	if (pfd != NULL)
+	    call close (pfd)
+
+	# Free centering structure.
+	call apcfree (ap)
+
+	# Close up the file lists.
+	call imtclose (imlist)
+	call clpcls (clist)
+	call clpcls (olist)
+	call sfree (sp)
+end
diff --git a/noao/digiphot/apphot/centerpars.par b/noao/digiphot/apphot/centerpars.par
new file mode 100644
index 00000000..1692b29e
--- /dev/null
+++ b/noao/digiphot/apphot/centerpars.par
@@ -0,0 +1,14 @@
+# CENTERPARS
+
+calgorithm,s,h,"centroid","|centroid|gauss|none|ofilter|",,Centering algorithm
+cbox,r,h,5.0,,,Centering box width in scale units
+cthreshold,r,h,0.0,,,Centering threshold in sigma above background
+minsnratio,r,h,1.0,0.0,,Minimum signal-to-noise ratio for centering algorithm
+cmaxiter,i,h,10,,,Maximum number of iterations for centering algorithm
+maxshift,r,h,1.0,,,Maximum center shift in scale units
+clean,b,h,no,,,Symmetry clean before centering ?
+rclean,r,h,1.0,,,Cleaning radius in scale units
+rclip,r,h,2.0,,,Clipping radius in scale units
+kclean,r,h,3.0,,,Rejection limit in sigma
+mkcenter,b,h,no,,,Mark the computed center on display ?
+mode,s,h,'ql'
diff --git a/noao/digiphot/apphot/daofind.par b/noao/digiphot/apphot/daofind.par
new file mode 100644
index 00000000..b6af78c1
--- /dev/null
+++ b/noao/digiphot/apphot/daofind.par
@@ -0,0 +1,21 @@
+# DAOFIND
+
+image,s,a,,,,"Input image(s)"
+output,f,h,"default",,,"The output coordinates list(s) (default: image.coo.?)"
+starmap,s,h,"",,,"The output density enhancement image(s)"
+skymap,s,h,"",,,"The output sky image(s)" 
+datapars,pset,h,"",,,"Data dependent parameters"
+findpars,pset,h,"",,,"Object detection parameters"
+boundary,s,h,nearest,,,"Boundary extension (constant, nearest, reflect, wrap)"
+constant,r,h,0.0,,,"Constant for constant boundary extension"
+interactive,b,h,no,,,"Interactive mode ?"
+icommands,*imcur,h,"",,,"Image cursor: [x y wcs] key [cmd]"
+gcommands,*gcur,h,"",,,"Graphics cursor: [x y wcs] key [cmd]"
+wcsout,s,h,)_.wcsout,,,"The output coordinate system (logical,tv,physical)"
+cache,b,h,)_.cache,,,"Cache the image pixels ?"
+verify,b,h,)_.verify,,,"Verify critical parameters in non-interactive mode ?"
+update,b,h,)_.update,,,"Update critical parameters in non-interactive mode ?"
+verbose,b,h,)_.verbose,,,"Print messages in non-interactive mode ?"
+graphics,s,h,)_.graphics,,,"Graphics device"
+display,s,h,)_.display,,,"Display device"
+mode,s,h,'ql'
diff --git a/noao/digiphot/apphot/daofind/apbfdfind.x b/noao/digiphot/apphot/daofind/apbfdfind.x
new file mode 100644
index 00000000..acf34ae4
--- /dev/null
+++ b/noao/digiphot/apphot/daofind/apbfdfind.x
@@ -0,0 +1,139 @@
+include <imhdr.h>
+include <imio.h>
+include <mach.h>
+include "../lib/apphot.h"
+include "../lib/noise.h"
+include "../lib/find.h"
+
+# AP_BFDFIND -- Find stars in an image using a pattern matching
+# technique.
+
+procedure ap_bfdfind (im, cnv, sky, out, ap, boundary, constant, verbose)
+
+pointer	im		# pointer to the input image
+pointer	cnv		# pointer to the convolved image
+pointer	sky		# pointer to the sky image
+int	out		# the output file descriptor
+pointer	ap		# pointer to the apphot structure
+int	boundary	# type of boundary extension
+real	constant	# constant for constant boundary extension
+int	verbose		# verbose switch
+
+int	norm, nxk, nyk, nstars, stid
+pointer	sp, gker2d, ngker2d, dker2d, skip
+real	a, b, c, f, gsums[LEN_GAUSS], skysigma, skymode, threshold, relerr
+real	dmax, dmin, xsigsq, ysigsq
+int	apstati(), ap_find()
+real	ap_egkernel(), apstatr()
+
+begin
+	# Compute the parameters of the Gaussian kernel.
+	call ap_egparams (FWHM_TO_SIGMA * apstatr (ap, FWHMPSF) *
+	    apstatr (ap, SCALE), apstatr (ap, RATIO), apstatr (ap, THETA),
+	    apstatr (ap, NSIGMA), a, b, c, f, nxk, nyk)
+
+	# Allocate working space.
+	call smark (sp)
+	call salloc (gker2d, nxk * nyk, TY_REAL)
+	call salloc (ngker2d, nxk * nyk, TY_REAL)
+	call salloc (dker2d, nxk * nyk, TY_REAL)
+	call salloc (skip, nxk * nyk, TY_INT)
+
+	# Compute the 1 and 2 D kernels.
+	if (IS_INDEFR(apstatr(ap, DATAMIN)) && IS_INDEFR(apstatr(ap,
+	    DATAMAX))) {
+	    norm = YES
+	    dmin = -MAX_REAL
+	    dmax = MAX_REAL
+	} else {
+	    norm = NO
+	    if (IS_INDEFR(apstatr (ap, DATAMIN)))
+		dmin = -MAX_REAL
+	    else
+		dmin = apstatr (ap, DATAMIN)
+	    if (IS_INDEFR(apstatr (ap, DATAMAX)))
+		dmax = MAX_REAL
+	    else
+		dmax = apstatr (ap, DATAMAX)
+	}
+	relerr = ap_egkernel (Memr[gker2d], Memr[ngker2d], Memr[dker2d],
+	    Memi[skip], nxk, nyk, gsums, a, b, c, f)
+
+	# Set up the image boundary extension characteristics.
+	call ap_imset (im, boundary, max (1 + nxk / 2, 1 + nyk / 2),
+	    constant)
+	call ap_imset (cnv, boundary, max (1 + nxk / 2, 1 + nyk / 2),
+	    constant)
+
+	# Convolve the input image with the Gaussian kernel. The resultant
+	# picture constains in each pixel the height of the Gaussian
+	# function centered in the subarray which best represents the data
+	# within a circle of nsigma * sigma of the Gaussian.
+
+	if (IM_ACMODE(cnv) != READ_ONLY) {
+	    if (norm == YES)
+	        call ap_fconvolve (im, cnv, sky, Memr[ngker2d], Memr[dker2d],
+		    Memi[skip], nxk, nyk, gsums[GAUSS_SGOP])
+	    else
+	        call ap_gconvolve (im, cnv, sky, Memr[gker2d], Memi[skip],
+		    nxk, nyk, gsums, dmin, dmax)
+	}
+
+	# Save the task parameters in the database file if the savepars
+	# switch is enabled, otherwise a simple list of detected objects
+	# is written to the data base file.
+
+	call ap_wfdparam (out, ap)
+
+	# Find all the objects in the input image with the specified image
+	# characteristics.
+
+	if (verbose == YES) {
+	    call printf ("\nImage: %s  ")
+		call pargstr (IM_HDRFILE(im))
+	    call printf ("fwhmpsf: %g  ratio: %g  theta: %g  nsigma: %g\n\n")
+		call pargr (apstatr (ap, FWHMPSF))
+		call pargr (apstatr (ap, RATIO))
+		call pargr (apstatr (ap, THETA))
+		call pargr (apstatr (ap, NSIGMA))
+	}
+
+	# Get the skymode and threshold.
+	skysigma = apstatr (ap, SKYSIGMA)
+	if (IS_INDEFR(skysigma)) {
+	    skymode = 0.0
+	    threshold = 0.0
+	} else {
+	    skymode = apstatr (ap, EPADU) * (skysigma ** 2 -
+	        (apstatr (ap, READNOISE) / apstatr (ap, EPADU)) ** 2)
+	    skymode = max (0.0, skymode)
+	    threshold = apstatr (ap, THRESHOLD) * skysigma
+	}
+
+	# Compute the x and y sigma.
+	xsigsq = (apstatr (ap, SCALE) * apstatr (ap, FWHMPSF) / 2.35482) ** 2
+	ysigsq = (apstatr (ap, SCALE) * apstatr (ap, RATIO) *
+	    apstatr (ap, FWHMPSF) / 2.35482) ** 2
+
+	# Find the stars.
+	stid = 1
+	nstars = ap_find (ap, im, cnv, out, NULL, Memr[gker2d],
+	    Memi[skip], nxk, nyk, skymode, threshold, relerr,
+	    apstati (ap,POSITIVE), xsigsq, ysigsq, dmin, dmax,
+	    apstatr (ap, SHARPLO), apstatr (ap, SHARPHI), apstatr (ap,
+	    ROUNDLO), apstatr (ap, ROUNDHI), verbose, stid, NO)
+
+	if (verbose == YES) {
+	    call printf (
+	        "\nthreshold: %g relerr: %5.3f  %g <= sharp <= %g  ")
+		call pargr (threshold)
+		call pargr (relerr)
+		call pargr (apstatr (ap, SHARPLO))
+		call pargr (apstatr (ap, SHARPHI))
+	    call printf ("%g <= round <= %g \n\n")
+		call pargr (apstatr (ap, ROUNDLO))
+		call pargr (apstatr (ap, ROUNDHI))
+	}
+
+	call sfree (sp)
+end
diff --git a/noao/digiphot/apphot/daofind/apconvolve.x b/noao/digiphot/apphot/daofind/apconvolve.x
new file mode 100644
index 00000000..0c6f58aa
--- /dev/null
+++ b/noao/digiphot/apphot/daofind/apconvolve.x
@@ -0,0 +1,320 @@
+include <imhdr.h>
+include <imset.h>
+include "../lib/find.h"
+
+# AP_FCONVOLVE --  Solve for the density enhancement image and optionally
+# the sky enhancement image in the case where datamin and datamax are not
+# defined.
+
+procedure ap_fconvolve (im, den, sky, kernel1, kernel2, skip, nxk, nyk, const2)
+
+pointer	im			# pointer to the input image
+pointer	den			# pointer to the output density image
+pointer	sky			# pointer to the output sky image
+real	kernel1[nxk,nyk]	# the first convolution kernel
+real	kernel2[nxk,nyk]	# the second convolution kernel
+int	skip[nxk,nyk]		# the skip array
+int	nxk, nyk		# dimensions of the kernel
+real	const2			# subtraction constant for the skyimage
+
+int	i, ncols, nlines, col1, col2, inline, outline
+pointer	sp, lineptrs, outbuf1, outbuf2
+pointer	imgs2r(), impl2r()
+errchk	imgs2r, impl2r, imflush
+
+begin
+	# Set up an array of linepointers.
+	call smark (sp)
+	call salloc (lineptrs, nyk, TY_POINTER)
+
+	# Set the number of image buffers.
+	call imseti (im, IM_NBUFS, nyk)
+
+	ncols = IM_LEN(den,1)
+	nlines = IM_LEN(den,2)
+
+	# Set input image column limits.
+	col1 = 1 - nxk / 2
+	col2 = IM_LEN(im,1) + nxk / 2
+
+	# Initialise the line buffers.
+	inline = 1 - nyk / 2
+	do i = 1 , nyk - 1 {
+	    Memi[lineptrs+i] = imgs2r (im, col1, col2, inline, inline)
+	    inline = inline + 1
+	}
+
+	# Generate the output image line by line.
+	do outline = 1, nlines {
+
+	    # Scroll the input buffers.
+	    do i = 1, nyk - 1
+		Memi[lineptrs+i-1] = Memi[lineptrs+i]
+
+	    # Read in new image line.
+	    Memi[lineptrs+nyk-1] = imgs2r (im, col1, col2, inline,
+	        inline)
+
+	    # Get first output image line.
+	    outbuf1 = impl2r (den, outline)
+	    if (outbuf1 == EOF)
+		call error (0, "Error writing first output image.")
+
+	    # Generate first output image line.
+	    call aclrr (Memr[outbuf1], ncols)
+	    do i = 1, nyk
+		call ap_skcnvr (Memr[Memi[lineptrs+i-1]], Memr[outbuf1],
+		    ncols, kernel1[1,i], skip[1,i], nxk)
+
+	    if (sky != NULL) {
+
+	        # Get second output image line.
+	        outbuf2 = impl2r (sky, outline)
+	        if (outbuf2 == EOF)
+		    call error (0, "Error writing second output image.")
+
+	        # Generate second output image line.
+	        call aclrr (Memr[outbuf2], ncols)
+	        do i = 1, nyk
+		    call ap_skcnvr (Memr[Memi[lineptrs+i-1]], Memr[outbuf2],
+		        ncols, kernel2[1,i], skip[1,i], nxk)
+		call ap_w1sur (Memr[outbuf2], Memr[outbuf1], Memr[outbuf2],
+		    ncols, -const2)
+	    }
+
+	    inline = inline + 1
+	}
+
+	# Flush the output image(s).
+	call imflush (den)
+	if (sky != NULL)
+	    call imflush (sky)
+
+	# Free the image buffer pointers.
+	call sfree (sp)
+end
+
+
+# AP_GCONVOLVE --  Solve for the density enhancement image and optionally
+# the sky enhancement image in the case where datamin and datamax are defined.
+
+procedure ap_gconvolve (im, den, sky, kernel1, skip, nxk, nyk, gsums,
+	datamin, datamax)
+
+pointer	im			# pointer to the input image
+pointer	den			# pointer to the output density image
+pointer	sky			# pointer to the output sky image
+real	kernel1[nxk,nyk]	# the first convolution kernel
+int	skip[nxk,nyk]		# the sky array
+int	nxk, nyk		# dimensions of the kernel
+real	gsums[ARB]		# array of kernel sums
+real	datamin, datamax	# the good data minimum and maximum
+
+int	i, ncols, nlines, col1, col2, inline, outline
+pointer	sp, lineptrs, sd, sgd, sg, sgsq, p, outbuf2
+pointer	imgs2r(), impl2r()
+errchk	imgs2r, impl2r, imflush
+
+begin
+	# Set up an array of linepointers.
+	call smark (sp)
+	call salloc (lineptrs, nyk, TY_POINTER)
+
+	# Set the number of image buffers.
+	call imseti (im, IM_NBUFS, nyk)
+
+	ncols = IM_LEN(den,1)
+	nlines = IM_LEN(den,2)
+
+	# Allocate some working space.
+	call salloc (sd, ncols, TY_REAL)
+	call salloc (sgsq, ncols, TY_REAL)
+	call salloc (sg, ncols, TY_REAL)
+	call salloc (p, ncols, TY_REAL)
+
+	# Set input image column limits.
+	col1 = 1 - nxk / 2
+	col2 = IM_LEN(im,1) + nxk / 2
+
+	# Initialise the line buffers.
+	inline = 1 - nyk / 2
+	do i = 1 , nyk - 1 {
+	    Memi[lineptrs+i] = imgs2r (im, col1, col2, inline, inline)
+	    inline = inline + 1
+	}
+
+	# Generate the output image line by line.
+	do outline = 1, nlines {
+
+	    # Scroll the input buffers.
+	    do i = 1, nyk - 1
+		Memi[lineptrs+i-1] = Memi[lineptrs+i]
+
+	    # Read in new image line.
+	    Memi[lineptrs+nyk-1] = imgs2r (im, col1, col2, inline,
+	        inline)
+
+	    # Get first output image line.
+	    sgd = impl2r (den, outline)
+	    if (sgd == EOF)
+		call error (0, "Error writing first output image.")
+
+	    # Generate first output image line.
+	    call aclrr (Memr[sgd], ncols)
+	    call aclrr (Memr[sd], ncols)
+	    call amovkr (gsums[GAUSS_SUMG], Memr[sg], ncols)
+	    call amovkr (gsums[GAUSS_SUMGSQ], Memr[sgsq], ncols)
+	    call amovkr (gsums[GAUSS_PIXELS], Memr[p], ncols)
+	    do i = 1, nyk
+		call ap_gdsum (Memr[Memi[lineptrs+i-1]], Memr[sgd], Memr[sd],
+		    Memr[sg], Memr[sgsq], Memr[p], ncols, kernel1[1,i],
+		    skip[1,i], nxk, datamin, datamax)
+	    call ap_gdavg (Memr[sgd], Memr[sd], Memr[sg], Memr[sgsq],
+	        Memr[p], ncols, gsums[GAUSS_PIXELS], gsums[GAUSS_DENOM],
+		gsums[GAUSS_SGOP])
+
+	    if (sky != NULL) {
+
+	        # Get second output image line.
+	        outbuf2 = impl2r (sky, outline)
+	        if (outbuf2 == EOF)
+		    call error (0, "Error writing second output image.")
+
+	        # Generate second output image line.
+		call ap_davg (Memr[sd], Memr[sgd], Memr[sg], Memr[p],
+		    Memr[outbuf2], ncols)
+	    }
+
+	    inline = inline + 1
+	}
+
+	# Flush the output image(s).
+	call imflush (den)
+	if (sky != NULL)
+	    call imflush (sky)
+
+	# Free the image buffer pointers.
+	call sfree (sp)
+end
+
+
+# AP_SKCNVR -- Compute the convolution kernel using a skip array.
+
+procedure ap_skcnvr (in, out, npix, kernel, skip, nk)
+
+real	in[npix+nk-1]		# the input vector
+real	out[npix]		# the output vector
+int	npix			# the size of the vector
+real	kernel[ARB]		# the convolution kernel
+int	skip[ARB]		# the skip array
+int	nk			# the size of the convolution kernel
+
+int	i, j
+real	sum
+
+begin
+	do i = 1, npix {
+	    sum = out[i]
+	    do j = 1, nk {
+		if (skip[j] == YES)
+		    next
+		sum = sum + in[i+j-1] * kernel[j]
+	    }
+	    out[i] = sum
+	}
+end
+
+
+# AP_GDSUM -- Compute the vector sums required to do the convolution.
+
+procedure  ap_gdsum (in, sgd, sd, sg, sgsq, p, npix, kernel, skip, nk,
+	datamin, datamax)
+
+real	in[npix+nk-1]		# the input vector
+real	sgd[ARB]		# the computed input/output convolution vector
+real	sd[ARB]			# the computed input/output sum vector
+real	sg[ARB]			# the input/ouput first normalization factor
+real	sgsq[ARB]		# the input/ouput second normalization factor
+real	p[ARB]			# the number of points vector
+int	npix			# the size of the vector
+real	kernel[ARB]		# the convolution kernel
+int	skip[ARB]		# the skip array
+int	nk			# the size of the convolution kernel
+real	datamin, datamax	# the good data limits.
+
+int	i, j
+real	data
+
+begin
+	do i = 1, npix {
+	    do j = 1, nk {
+		if (skip[j] == YES)
+		    next
+		data = in[i+j-1]
+		if (data < datamin || data > datamax) {
+		    sgsq[i] = sgsq[i] - kernel[j] ** 2
+		    sg[i] = sg[i] - kernel[j]
+		    p[i] = p[i] - 1.0
+		} else {
+		    sgd[i] = sgd[i] + kernel[j] * data 
+		    sd[i] = sd[i] + data
+		}
+	    }
+	}
+end
+
+
+# AP_GDAVG -- Compute the vector averages required to do the convolution.
+
+procedure  ap_gdavg (sgd, sd, sg, sgsq, p, npix, pixels, denom, sgop)
+
+real	sgd[ARB]		# the computed input/output convolution vector
+real	sd[ARB]			# the computed input/output sum vector
+real	sg[ARB]			# the input/ouput first normalization factor
+real	sgsq[ARB]		# the input/ouput second normalization factor
+real	p[ARB]			# the number of points vector
+int	npix			# the size of the vector
+real	pixels			# number of pixels
+real	denom			# kernel normalization factor
+real	sgop			# kernel normalization factor
+
+int	i
+
+begin
+	do i = 1, npix {
+	    if (p[i] > 1.5) {
+		if (p[i] < pixels) {
+		    sgsq[i] = sgsq[i] - (sg[i] ** 2) / p[i]
+		    if (sgsq[i] != 0.0)
+			sgd[i] = (sgd[i] - sg[i] * sd[i] / p[i]) / sgsq[i]
+		    else
+			sgd[i] = 0.0
+		} else
+		    sgd[i] = (sgd[i] - sgop * sd[i]) / denom
+	    } else
+		sgd[i] = 0.0
+	}
+end
+
+
+# AP_DAVG -- Generate the results the optional sky output image.
+
+procedure ap_davg (sd, sgd, sg, p, out, npix)
+
+real	sd[ARB]			# the computed input/output sum vector
+real	sgd[ARB]		# the computed input/output convolution vector
+real	sg[ARB]			# the input/ouput first normalization factor
+real	p[ARB]			# the number of points vector
+real	out[ARB]		# the output array
+int	npix			# the size of the vector
+
+int	i
+
+begin
+	do i = 1, npix {
+	    if (p[i] > 0.0)
+	        out[i] = (sd[i] - sgd[i] * sg[i]) / p[i]
+	    else
+		out[i] = 0.0
+	}
+end
diff --git a/noao/digiphot/apphot/daofind/apegkernel.x b/noao/digiphot/apphot/daofind/apegkernel.x
new file mode 100644
index 00000000..3023098d
--- /dev/null
+++ b/noao/digiphot/apphot/daofind/apegkernel.x
@@ -0,0 +1,132 @@
+include <math.h>
+include "../lib/find.h"
+
+# Set up the gaussian fitting structure. 
+
+# AP_EGPARAMS -- Calculate the parameters of the elliptical Gaussian needed
+# to compute the kernel.
+
+procedure ap_egparams (sigma, ratio, theta, nsigma, a, b, c, f, nx, ny)
+
+real	sigma			# sigma of Gaussian in x
+real	ratio			# Ratio of half-width in y to x
+real	theta			# position angle of Gaussian
+real	nsigma			# limit of convolution
+real	a, b, c, f		# ellipse parameters
+int	nx, ny			# dimensions of the kernel
+
+real	sx2, sy2, cost, sint, discrim
+bool	fp_equalr ()
+
+begin
+	# Define some temporary variables.
+	sx2 = sigma ** 2
+	sy2 = (ratio * sigma) ** 2
+	cost = cos (DEGTORAD (theta))
+	sint = sin (DEGTORAD (theta))
+
+	# Compute the ellipse parameters.
+	if (fp_equalr (ratio, 0.0)) {
+	    if (fp_equalr (theta, 0.0) || fp_equalr (theta, 180.)) {
+		a = 1. / sx2
+		b = 0.0
+		c = 0.0
+	    } else if (fp_equalr (theta, 90.0)) {
+		a = 0.0
+		b = 0.0
+		c = 1. / sx2
+	    } else
+		call error (0, "AP_EGPARAMS: Cannot make 1D Gaussian.")
+	    f = nsigma ** 2 / 2.
+	    nx = 2 * int (max (sigma * nsigma * abs (cost), RMIN)) + 1
+	    ny = 2 * int (max (sigma * nsigma * abs (sint), RMIN)) + 1
+	} else {
+	    a = cost ** 2 / sx2 + sint ** 2 / sy2
+	    b = 2. * (1.0 / sx2 - 1.0 / sy2) * cost * sint
+	    c = sint ** 2 / sx2 + cost ** 2 / sy2
+	    discrim = b ** 2 - 4. * a * c
+	    f = nsigma ** 2 / 2.
+	    nx = 2 * int (max (sqrt (-8. * c * f / discrim), RMIN)) + 1
+	    ny = 2 * int (max (sqrt (-8. * a * f / discrim), RMIN)) + 1
+	}
+end
+
+
+# AP_EGKERNEL -- Compute the elliptical Gaussian kernel.
+
+real procedure ap_egkernel (gkernel, ngkernel, dkernel, skip, nx, ny, gsums, a,
+	b, c, f)
+
+real	gkernel[nx,ny]		# output Gaussian amplitude kernel
+real	ngkernel[nx,ny]		# output normalized Gaussian amplitude kernel
+real	dkernel[nx,ny]		# output Gaussian sky kernel
+int	skip[nx,ny]		# output skip subraster
+int	nx, ny			# input dimensions of the kernel
+real	gsums[ARB]		# output array of gsums
+real	a, b, c, f		# ellipse parameters
+
+int	i, j, x0, y0, x, y
+real	npts, rjsq, rsq, relerr,ef
+
+begin
+	# Initialize.
+	x0 = nx / 2 + 1
+	y0 = ny / 2 + 1
+	gsums[GAUSS_SUMG] = 0.0
+	gsums[GAUSS_SUMGSQ] = 0.0
+	npts = 0.0
+
+	# Compute the kernel and principal sums.
+	do j = 1, ny {
+	    y = j - y0
+	    rjsq = y ** 2
+	    do i = 1, nx {
+		x = i - x0
+		rsq = sqrt (x ** 2 + rjsq)
+		ef = 0.5 * (a * x ** 2 + c * y ** 2 + b * x * y)
+		gkernel[i,j] = exp (-1.0 * ef)
+		if (ef <= f || rsq <= RMIN) {
+		    #gkernel[i,j] = exp (-ef)
+		    ngkernel[i,j] = gkernel[i,j]
+		    dkernel[i,j] = 1.0
+		    gsums[GAUSS_SUMG] = gsums[GAUSS_SUMG] + gkernel[i,j]
+		    gsums[GAUSS_SUMGSQ] = gsums[GAUSS_SUMGSQ] +
+		        gkernel[i,j] ** 2
+		    skip[i,j] = NO
+		    npts = npts + 1.0
+		} else {
+		    #gkernel[i,j] = 0.0
+		    ngkernel[i,j] = 0.0
+		    dkernel[i,j] = 0.0
+		    skip[i,j] = YES
+		}
+	    }
+	}
+
+	# Store the remaining sums.
+	gsums[GAUSS_PIXELS] = npts
+	gsums[GAUSS_DENOM] = gsums[GAUSS_SUMGSQ] - gsums[GAUSS_SUMG] ** 2 /
+	    npts
+	gsums[GAUSS_SGOP] = gsums[GAUSS_SUMG] / npts
+
+	# Normalize the amplitude kernel.
+	do j = 1, ny {
+	     do i = 1, nx {
+	        if (skip[i,j] == NO)
+		    ngkernel[i,j] = (gkernel[i,j] - gsums[GAUSS_SGOP]) /
+			gsums[GAUSS_DENOM]
+	    }
+	}
+
+	# Normalize the sky kernel
+	do j = 1, ny {
+	    do i = 1, nx {
+		if (skip[i,j] == NO)
+		    dkernel[i,j] = dkernel[i,j] / npts
+	    }
+	}
+
+	relerr = 1.0 / gsums[GAUSS_DENOM]
+
+	return (sqrt (relerr))
+end
diff --git a/noao/digiphot/apphot/daofind/apfdcolon.x b/noao/digiphot/apphot/daofind/apfdcolon.x
new file mode 100644
index 00000000..cb618bb9
--- /dev/null
+++ b/noao/digiphot/apphot/daofind/apfdcolon.x
@@ -0,0 +1,282 @@
+include "../lib/apphot.h"
+include "../lib/display.h"
+include "../lib/noise.h"
+include "../lib/find.h"
+
+# AP_FDCOLON -- Process colon commands from the daofind task.
+
+procedure ap_fdcolon (ap, im, out, stid, cmdstr, newimage, newbuf, newfit)
+
+pointer	ap		# pointer to the apphot structure
+pointer	im		# pointer to the iraf image
+int	out		# output file descriptor
+int	stid		# output file sequence number
+char	cmdstr		# command string
+int	newimage	# new mage ?
+int	newbuf		# new center buffer ?
+int	newfit		# new center fit ?
+
+int	cl, junk
+pointer	sp, incmd, outcmd
+int	strdic()
+
+begin
+	call smark (sp)
+	call salloc (incmd, SZ_LINE, TY_CHAR)
+	call salloc (outcmd, SZ_LINE, TY_CHAR)
+
+	# Get the command.
+	call sscan (cmdstr)
+	call gargwrd (Memc[incmd], SZ_LINE)
+	if (Memc[incmd] == EOS) {
+	    call sfree (sp)
+	    return
+	}
+
+	# Process the command making sure that the pointer to the
+	# coords file is always NULL.
+	if (strdic (Memc[incmd], Memc[outcmd], SZ_LINE, APCMDS) != 0) {
+	    cl = NULL
+	    call ap_apcolon (ap, im, cl, out, stid, junk, cmdstr, newimage,
+	        junk, junk, junk, junk, newbuf, newfit)
+	    if (cl != NULL) {
+		call close (cl)
+		cl = NULL
+		call apsets (ap, CLNAME, "")
+	    }
+	} else if (strdic (Memc[incmd], Memc[outcmd], SZ_LINE, NCMDS) != 0) {
+	    call ap_nscolon (ap, im, out, stid, cmdstr, junk, junk,
+		junk, junk, newbuf, newfit)
+	} else if (strdic (Memc[incmd], Memc[outcmd], SZ_LINE, FCMDS) != 0) {
+	    call ap_fcolon (ap, out, stid, cmdstr, newbuf, newfit)
+	} else {
+	    call ap_fimcolon (ap, cmdstr)
+	}
+
+	call sfree (sp)
+end
+
+
+# AP_FCOLON -- Process colon commands for setting the find algorithm
+# parameters.
+
+procedure ap_fcolon (ap, out, stid, cmdstr, newbuf, newfit)
+
+pointer	ap			# pointer to the apphot structure
+int	out			# output file descriptor
+int	stid			# file number id
+char	cmdstr[ARB]		# command string
+int	newbuf, newfit		# change magnitude parameters
+
+bool	bval
+int	ncmd
+pointer	sp, cmd, str
+real	rval
+
+bool	itob()
+int	strdic(), nscan(), btoi(), apstati()
+real	apstatr()
+
+begin
+	call smark (sp)
+	call salloc (cmd, SZ_LINE, TY_CHAR)
+	call salloc (str, SZ_LINE, TY_CHAR)
+
+	# Get the command.
+	call sscan (cmdstr)
+	    call gargwrd (Memc[cmd], SZ_LINE)
+	if (Memc[cmd] == EOS) {
+	    call sfree (sp)
+	    return
+	}
+
+	# Process the command.
+	ncmd = strdic (Memc[cmd], Memc[cmd], SZ_LINE, FCMDS)
+	switch (ncmd) {
+
+	case FCMD_NSIGMA:
+	    call gargr (rval)
+	    if (nscan() == 1) {
+		call printf ("%s = %g %s\n")
+		    call pargstr (KY_NSIGMA)
+		    call pargr (apstatr (ap, NSIGMA))
+		    call pargstr (UN_FSIGMA)
+	    } else {
+		call apsetr (ap, NSIGMA, rval)
+		if (stid > 1)
+		    call ap_rparam (out, KY_NSIGMA, rval, UN_FSIGMA,
+			"size of kernel in sigma")
+		newbuf = YES; newfit = YES
+	    }
+
+	case FCMD_RATIO:
+	    call gargr (rval)
+	    if (nscan() == 1) {
+		call printf ("%s = %g %s\n")
+		    call pargstr (KY_RATIO)
+		    call pargr (apstatr (ap, RATIO))
+		    call pargstr (UN_FNUMBER)
+	    } else {
+		call apsetr (ap, RATIO, rval)
+		if (stid > 1)
+		    call ap_rparam (out, KY_RATIO, rval, UN_FNUMBER,
+			"sigma y / x of Gaussian kernel")
+		newbuf = YES; newfit = YES
+	    }
+
+	case FCMD_SHARPLO:
+	    call gargr (rval)
+	    if (nscan() == 1) {
+		call printf ("%s = %g %s\n")
+		    call pargstr (KY_SHARPLO)
+		    call pargr (apstatr (ap, SHARPLO))
+		    call pargstr (UN_FNUMBER)
+	    } else {
+		call apsetr (ap, SHARPLO, rval)
+		if (stid > 1)
+		    call ap_rparam (out, KY_SHARPLO, rval, UN_FNUMBER,
+			"lower sharpness bound")
+		newfit = YES
+	    }
+
+	case FCMD_SHARPHI:
+	    call gargr (rval)
+	    if (nscan() == 1) {
+		call printf ("%s = %g %s\n")
+		    call pargstr (KY_SHARPHI)
+		    call pargr (apstatr (ap, SHARPHI))
+		    call pargstr (UN_FNUMBER)
+	    } else {
+		call apsetr (ap, SHARPHI, rval)
+		if (stid > 1)
+		    call ap_rparam (out, KY_SHARPHI, rval, UN_FNUMBER,
+			"upper sharpness bound")
+		newfit = YES
+	    }
+
+	case FCMD_ROUNDLO:
+	    call gargr (rval)
+	    if (nscan() == 1) {
+		call printf ("%s = %g %s\n")
+		    call pargstr (KY_ROUNDLO)
+		    call pargr (apstatr (ap, ROUNDLO))
+		    call pargstr (UN_FNUMBER)
+	    } else {
+		call apsetr (ap, ROUNDLO, rval)
+		if (stid > 1)
+		    call ap_rparam (out, KY_ROUNDLO, rval, UN_FNUMBER,
+			"lower roundness bound")
+		newfit = YES
+	    }
+
+	case FCMD_ROUNDHI:
+	    call gargr (rval)
+	    if (nscan() == 1) {
+		call printf ("%s = %g %s\n")
+		    call pargstr (KY_ROUNDHI)
+		    call pargr (apstatr (ap, ROUNDHI))
+		    call pargstr (UN_FNUMBER)
+	    } else {
+		call apsetr (ap, ROUNDHI, rval)
+		if (stid > 1)
+		    call ap_rparam (out, KY_ROUNDHI, rval, UN_FNUMBER,
+			"upper roundness bound")
+		newfit = YES
+	    }
+
+	case FCMD_MKDETECTIONS:
+	    call gargb (bval)
+	    if (nscan () == 1) {
+		call printf ("%s = %b\n")
+		    call pargstr (KY_MKDETECTIONS)
+		    call pargb (itob (apstati (ap, MKDETECTIONS)))
+	    } else
+		call apseti (ap, MKDETECTIONS, btoi (bval))
+
+	case FCMD_THETA:
+	    call gargr (rval)
+	    if (nscan() == 1) {
+		call printf ("%s = %g %s\n")
+		    call pargstr (KY_THETA)
+		    call pargr (apstatr (ap, THETA))
+		    call pargstr (UN_FDEGREES)
+	    } else {
+		call apsetr (ap, THETA, rval)
+		if (stid > 1)
+		    call ap_rparam (out, KY_THETA, rval, UN_FDEGREES,
+			"position angle")
+		newbuf = YES; newfit = YES
+	    }
+
+	case FCMD_THRESHOLD:
+	    call gargr (rval)
+	    if (nscan() == 1) {
+		call printf ("%s = %g %s\n")
+		    call pargstr (KY_THRESHOLD)
+		    call pargr (apstatr (ap, THRESHOLD))
+		    call pargstr (UN_FSIGMA)
+	    } else {
+		call apsetr (ap, THRESHOLD, rval)
+		if (stid > 1)
+		    call ap_rparam (out, KY_THRESHOLD, rval, UN_FSIGMA,
+			"detection threshold in sigma")
+		newfit = YES
+	    }
+
+	default:
+	    call printf ("Unknown or ambiguous colon command\7\n")
+	}
+
+	call sfree (sp)
+end
+
+
+# AP_FIMCOLON --  Process colon commands for the daofind task that do
+# not affect the data dependent or find parameters.
+
+procedure ap_fimcolon (ap, cmdstr)
+
+pointer	ap			# pointer to the apphot structure
+char	cmdstr[ARB]		# command string
+
+int	ncmd
+pointer	sp, cmd
+int	strdic()
+
+begin
+	# Get the command.
+	call smark (sp)
+	call salloc (cmd, SZ_LINE, TY_CHAR)
+	call sscan (cmdstr)
+	call gargwrd (Memc[cmd], SZ_LINE)
+	if (Memc[cmd] == EOS) {
+	    call sfree (sp)
+	    return
+	}
+
+	# Process the command.
+	ncmd = strdic (Memc[cmd], Memc[cmd], SZ_LINE, MISC1)
+	switch (ncmd) {
+	case ACMD_SHOW:
+	    call gargwrd (Memc[cmd], SZ_LINE)
+	    ncmd = strdic (Memc[cmd], Memc[cmd], SZ_LINE, FSHOWARGS)
+	    switch (ncmd) {
+	    case FCMD_DATA:
+		call printf ("\n")
+		call ap_nshow (ap)
+		call printf ("\n")
+	    case FCMD_FIND:
+		call printf ("\n")
+	        call ap_fshow (ap)
+		call printf ("\n")
+	    default:
+		call printf ("\n")
+	        call ap_fdshow (ap)
+		call printf ("\n")
+	    }
+	default:
+	    call printf ("Unknown or ambiguous colon command\7\n")
+	}
+
+	call sfree (sp)
+end
diff --git a/noao/digiphot/apphot/daofind/apfdconfirm.x b/noao/digiphot/apphot/daofind/apfdconfirm.x
new file mode 100644
index 00000000..ce69cbd9
--- /dev/null
+++ b/noao/digiphot/apphot/daofind/apfdconfirm.x
@@ -0,0 +1,22 @@
+# AP_FDCONFIRM -- Procedure to confirm the critical daofind parameters.
+
+procedure ap_fdconfirm (ap)
+
+pointer	ap		# pointer to the apphot structure
+
+real	rval
+real	ap_vfwhmpsf(), ap_vsigma(), ap_vthreshold()
+real	ap_vdatamin(), ap_vdatamax()
+
+begin
+	call printf ("\n")
+
+	# Verify the critical parameters.
+	rval = ap_vfwhmpsf (ap)
+	rval = ap_vsigma (ap)
+	rval = ap_vthreshold (ap)
+	rval = ap_vdatamin (ap)
+	rval = ap_vdatamax (ap)
+
+	call printf ("\n")
+end
diff --git a/noao/digiphot/apphot/daofind/apfdfind.x b/noao/digiphot/apphot/daofind/apfdfind.x
new file mode 100644
index 00000000..7778c946
--- /dev/null
+++ b/noao/digiphot/apphot/daofind/apfdfind.x
@@ -0,0 +1,213 @@
+include <imhdr.h>
+include "../lib/apphot.h"
+include "../lib/display.h"
+include "../lib/find.h"
+
+define	HELPFILE	"apphot$daofind/daofind.key"
+
+# AP_FDFIND -- Find objects in an image interactively.
+
+int procedure ap_fdfind (denname, skyname, ap, im, gd, id, out, boundary,
+	constant, save, skysave, interactive, cache)
+
+char	denname[ARB]		# name of density enhancement image
+char	skyname[ARB]		# name of the fitted sky image
+pointer ap			# pointer to the apphot structure
+pointer	im			# pointer to the IRAF image
+pointer	gd			# pointer to the graphics stream
+pointer	id			# pointer to the image display stream
+int	out			# output file descriptor
+int	boundary		# type of boundary extension
+real	constant		# constatn for constant boundary extension
+int	save			# save convolved image
+int	skysave			# save the sky image
+int	interactive		# interactive mode
+int	cache			# cache the input image pixels
+
+real	wx, wy
+pointer	sp, cmd, root, den, sky
+int	wcs, key, newimage, newden, newfit, stid, memstat, req_size, old_size
+int	buf_size
+
+real	apstatr()
+pointer	ap_immap()
+int	clgcur(), apgqverify(), apgtverify(), sizeof(), ap_memstat()
+
+begin
+	call smark (sp)
+	call salloc (cmd, SZ_LINE, TY_CHAR)
+	call salloc (root, SZ_FNAME, TY_CHAR)
+
+	# Initialize cursor command.
+	key = ' '
+	Memc[cmd] = EOS
+	call strcpy (" ", Memc[root], SZ_FNAME)
+
+	# Initialize fitting parameters.
+	den = NULL
+	sky = NULL
+	newimage = NO
+	newden = YES
+	newfit = YES
+	memstat = NO
+
+	# Loop over the cursor commands.
+	stid = 1
+	while (clgcur ("icommands", wx, wy, wcs, key, Memc[cmd], SZ_LINE) !=
+	    EOF) {
+
+	    # Store the current cursor coordinates.
+	    call ap_vtol (im, wx, wy, wx, wy, 1)
+	    call apsetr (ap, CWX, wx)
+	    call apsetr (ap, CWY, wy)
+
+	    # Process the colon commands.
+	    switch (key) {
+
+	    # Quit.
+	    case 'q':
+		if (interactive == YES && apgqverify ("daofind",
+		    ap, key) == YES) {
+		    call sfree (sp)
+		    if (den != NULL) {
+	    	        call imunmap (den)
+		        if (save == NO)
+	    	            call imdelete (denname)
+		    }
+		    if (sky != NULL)
+			call imunmap (sky)
+		    return (apgtverify (key))
+		} else {
+		    if (den != NULL) {
+	    	        call imunmap (den)
+		        if (save == NO)
+	    	            call imdelete (denname)
+		    }
+		    if (sky != NULL)
+			call imunmap (sky)
+		    call sfree (sp)
+		    return (YES)
+		}
+
+	    # Get information on keystroke commands.
+	    case '?':
+		if ((id != NULL) && (gd == id))
+		    call gpagefile (id, HELPFILE, "")
+		else if (interactive == YES)
+		    call pagefile (HELPFILE, "[space=morehelp,q=quit,?=help]")
+
+	    # Plot a centered stellar radial profile
+	    case 'd':
+		if (interactive == YES)
+		    call ap_qrad (ap, im, wx, wy, gd)
+
+	    # Interactively set the daofind parameters.
+	    case 'i':
+		if (interactive == YES) {
+		    call ap_fdradsetup (ap, im, wx, wy, gd, out, stid)
+		    newden = YES
+		    newfit = YES
+		}
+
+	    # Verify the critical daofind parameters.
+	    case 'v':
+		call ap_fdconfirm (ap)
+		newden = YES
+		newfit = YES
+
+	    # Save daofind parameters in the pset files.
+	    case 'w':
+		call ap_fdpars (ap)
+
+	    # Process apphot : commands.
+	    case ':':
+		call ap_fdcolon (ap, im, out, stid, Memc[cmd], newimage,
+		    newden, newfit)
+
+		# Determine the viewport and data window of image display.
+		if (newimage == YES) {
+		    if ((id != NULL) && (id != gd))
+		        call ap_gswv (id, Memc[cmd], im, 4)
+            	    req_size = MEMFUDGE * (IM_LEN(im,1) * IM_LEN(im,2) *
+                	sizeof (IM_PIXTYPE(im)) + 2 * IM_LEN(im,1) *
+			IM_LEN(im,2) * sizeof (TY_REAL))
+                    memstat = ap_memstat (cache, req_size, old_size)
+                    if (memstat == YES)
+                        call ap_pcache (im, INDEFI, buf_size)
+		}
+		newimage = NO
+
+	    # Find the stars.
+	    case 'f', ' ':
+
+		if (newden == YES) {
+
+		    if (den != NULL) {
+			call imunmap (den)
+		        call imdelete (denname)
+		    }
+		    den = ap_immap (denname, im, ap, save)
+                    if (memstat == YES)
+                        call ap_pcache (den, INDEFI, buf_size)
+
+		    if (sky != NULL)
+			call imunmap (sky)
+		    if (skysave == YES) {
+		        sky = ap_immap (skyname, im, ap, YES)
+                        if (memstat == YES)
+                            call ap_pcache (den, INDEFI, buf_size)
+		    } else
+			sky = NULL
+		    newden = NO
+
+		    if (key == 'f') {
+		        call ap_fdstars (im, ap, den, sky, NULL, id,
+			    boundary, constant, NO, stid)
+		    } else {
+		        call ap_outmap (ap, out, Memc[root])
+		        call ap_fdstars (im, ap, den, sky, out, id,
+			    boundary, constant, NO, stid)
+			newfit = NO
+		    }
+
+		} else if (newfit == YES) {
+
+		    if (key == 'f') {
+		        call ap_fdstars (im, ap, den, sky, NULL, id,
+			    boundary, constant, YES, stid)
+		    } else {
+		        call ap_outmap (ap, out, Memc[root])
+		        call ap_fdstars (im, ap, den, sky, out, id,
+			    boundary, constant, YES, stid)
+			newfit = NO
+		    }
+
+		} else {
+		    call printf ("Detection parameters have not changed\n")
+		}
+
+		if (id != NULL) {
+		    if (id == gd)
+			call gflush (id)
+		    else
+			call gframe (id) 
+		}
+
+		stid = 1
+		#newden = NO
+		#newfit = NO
+
+	    default:
+		# do nothing
+		call printf ("Unknown or ambiguous keystroke command\n")
+	    }
+
+	    # Setup for the next object.
+	    key = ' '
+	    Memc[cmd] = EOS
+	    call apsetr (ap, WX, apstatr (ap, CWX))
+	    call apsetr (ap, WY, apstatr (ap, CWY))
+
+	}
+
+end
diff --git a/noao/digiphot/apphot/daofind/apfdfree.x b/noao/digiphot/apphot/daofind/apfdfree.x
new file mode 100644
index 00000000..3f1ea762
--- /dev/null
+++ b/noao/digiphot/apphot/daofind/apfdfree.x
@@ -0,0 +1,34 @@
+include "../lib/apphotdef.h"
+
+# AP_FDFREE -- Free the apphot data structure.
+
+procedure ap_fdfree (ap)
+
+pointer	ap		# pointer to the apphot structure
+
+begin
+	if (ap == NULL)
+	    return
+	if (AP_NOISE(ap) != NULL)
+	    call ap_noisecls (ap)
+	if (AP_PFIND(ap) != NULL)
+	    call ap_fdcls (ap)
+	if (AP_PDISPLAY(ap) != NULL)
+	    call ap_dispcls (ap)
+	if (AP_IMBUF(ap) != NULL)
+	    call mfree (AP_IMBUF(ap), TY_REAL)
+	if (AP_MW(ap) != NULL)
+	    call mw_close (AP_MW(ap))
+	call mfree (ap, TY_STRUCT)
+end
+
+
+# AP_FDCLS -- Free the find data structure.
+
+procedure ap_fdcls (ap)
+
+pointer	ap		# pointer to the apphot structure
+
+begin
+	call mfree (AP_PFIND(ap), TY_STRUCT)
+end
diff --git a/noao/digiphot/apphot/daofind/apfdgpars.x b/noao/digiphot/apphot/daofind/apfdgpars.x
new file mode 100644
index 00000000..95d87d23
--- /dev/null
+++ b/noao/digiphot/apphot/daofind/apfdgpars.x
@@ -0,0 +1,20 @@
+include "../lib/noise.h"
+include "../lib/display.h"
+
+# AP_FDGPARS -- Open up the apphot data structure and get the daofind input
+# parameters.
+
+procedure ap_fdgpars (ap)
+
+pointer	ap			# pointer to the apphot structure
+
+begin
+	# Open the apphot structure.
+	call ap_fdinit (ap, 2.0, AP_NPOISSON)
+
+	# Get the data dependent parameters.
+	call ap_gdapars (ap)
+
+	# Get the find parameters.
+	call ap_gfipars (ap)
+end
diff --git a/noao/digiphot/apphot/daofind/apfdinit.x b/noao/digiphot/apphot/daofind/apfdinit.x
new file mode 100644
index 00000000..9c31b494
--- /dev/null
+++ b/noao/digiphot/apphot/daofind/apfdinit.x
@@ -0,0 +1,59 @@
+include "../lib/apphotdef.h"
+include "../lib/finddef.h"
+
+# AP_FDINIT - Initialize the daofind data structure.
+
+procedure ap_fdinit (ap, fwhmpsf, noise)
+
+pointer	ap		# pointer to the apphot structure
+real	fwhmpsf		# FWHM of the PSF
+int	noise		# noise function
+
+begin
+	# Allocate space.
+	call malloc (ap, LEN_APSTRUCT, TY_STRUCT)
+
+	# Set the default global apphot package parameters.
+	call ap_defsetup (ap, fwhmpsf)
+
+	# Setup the noise structure.
+	call ap_noisesetup (ap, noise)
+
+	# Setup the display structure.
+	call ap_dispsetup (ap)
+
+	# Setup the find structure.
+	call ap_fdsetup (ap)
+	    
+	# Unused structures are set to null.
+	AP_PCENTER(ap) = NULL
+	AP_PSKY(ap) = NULL
+	AP_PPSF(ap) = NULL
+	AP_PPHOT(ap) = NULL
+	AP_POLY(ap) = NULL
+	AP_RPROF(ap) = NULL
+end
+
+
+# AP_FDSETUP -- Initialize the find structure.
+
+procedure ap_fdsetup (ap)
+
+pointer	ap		# pointer to the apphot strucuture
+
+pointer	fnd
+
+begin
+	call malloc (AP_PFIND(ap), LEN_FIND, TY_STRUCT)
+	fnd = AP_PFIND(ap)
+
+	AP_RATIO(fnd) = DEF_RATIO
+	AP_THETA(fnd) = DEF_RATIO
+	AP_NSIGMA(fnd) = DEF_NSIGMA
+
+	AP_THRESHOLD(fnd) = DEF_THRESHOLD
+	AP_SHARPLO(fnd) = DEF_SHARPLO
+	AP_SHARPHI(fnd) = DEF_SHARPHI
+	AP_ROUNDLO(fnd) = DEF_ROUNDLO
+	AP_ROUNDHI(fnd) = DEF_ROUNDLO
+end
diff --git a/noao/digiphot/apphot/daofind/apfdpars.x b/noao/digiphot/apphot/daofind/apfdpars.x
new file mode 100644
index 00000000..108f205b
--- /dev/null
+++ b/noao/digiphot/apphot/daofind/apfdpars.x
@@ -0,0 +1,16 @@
+include "../lib/display.h"
+
+# AP_FDPARS -- Write out the current daofind parameters to the current
+# parameter files.
+
+procedure ap_fdpars (ap)
+
+pointer	ap		# pointer to apphot structure
+
+begin
+	# Write the data dependent parameters.
+	call ap_dapars (ap)
+
+	# Write the daofind parameters.
+	call ap_fipars (ap)
+end
diff --git a/noao/digiphot/apphot/daofind/apfdradsetup.x b/noao/digiphot/apphot/daofind/apfdradsetup.x
new file mode 100644
index 00000000..708d2690
--- /dev/null
+++ b/noao/digiphot/apphot/daofind/apfdradsetup.x
@@ -0,0 +1,82 @@
+define	HELPFILE	 "apphot$daofind/idaofind.key"
+
+# AP_FDRADSETUP -- Procedure to set up daofind interactively using the radial
+# profile plot of a bright star.
+
+procedure ap_fdradsetup (ap, im, wx, wy, gd, out, stid)
+
+pointer	ap			# pointer to apphot structure
+pointer	im			# pointer to the IRAF image
+real	wx, wy			# cursor coordinates
+pointer	gd			# pointer to graphics stream
+int	out			# output file descriptor
+int	stid			# output file sequence number)
+
+int	key, wcs
+pointer	sp, cmd
+real	rmin, rmax, imin, imax, xcenter, ycenter, rval
+real	u1, u2, v1, v2, x1, x2, y1, y2
+int	ap_showplot(), clgcur()
+real	ap_cfwhmpsf(), ap_csigma(), ap_cdatamin(), ap_cdatamax()
+
+begin
+	# Check for open graphics stream.
+	if (gd == NULL)
+	    return
+	call greactivate (gd, 0)
+
+	# Store the old viewport and window coordinates.
+	call ggview (gd, u1, u2, v1, v2)
+	call ggwind (gd, x1, x2, y1, y2)
+
+	# Make the plot.
+	if (ap_showplot (ap, im, wx, wy, gd, xcenter, ycenter, rmin, rmax,
+	    imin, imax) == ERR) {
+	    call gdeactivate (gd, 0)
+	    return
+	}
+
+	# Initialize.
+	call smark (sp)
+	call salloc (cmd, SZ_LINE, TY_CHAR)
+
+	call printf (
+	"Waiting for setup menu command (?=help, v=default setup, q=quit):\n")
+	while (clgcur ("gcommands", xcenter, ycenter, wcs, key, Memc[cmd],
+	    SZ_LINE) != EOF) {
+
+	# Enter the cursor setup loop.
+	switch (key) {
+	    case 'q':
+	        break
+	    case '?':
+		call gpagefile (gd, HELPFILE, "")
+	    case 'f':
+	        rval = ap_cfwhmpsf (ap, gd, out, stid, rmin, rmax, imin, imax)
+	    case 's':
+	        rval = ap_csigma (ap, gd, out, stid, rmin, rmax, imin, imax)
+	    case 'l':
+	        rval = ap_cdatamin (ap, gd, out, stid, rmin, rmax, imin, imax)
+	    case 'u':
+	        rval = ap_cdatamax (ap, gd, out, stid, rmin, rmax, imin, imax)
+	    case 'v':
+	        rval = ap_cfwhmpsf (ap, gd, out, stid, rmin, rmax, imin, imax)
+	        rval = ap_csigma (ap, gd, out, stid, rmin, rmax, imin, imax)
+	    default:
+		call printf ("Unknown or ambiguous keystroke command\007\n")
+	    }
+	    call printf (
+	 "Waiting for setup menu command (?=help, v=default setup, q=quit):\n")
+	}
+
+	# Interactive setup is complete.
+	call printf (
+	    "Interactive setup is complete. Type w to store parameters.\n")
+
+	# Restore the viewport and window coordinates.
+	call gsview (gd, u1, u2, v1, v2)
+	call gswind (gd, x1, x2, y1, y2)
+
+	call gdeactivate (gd, 0)
+	call sfree (sp)
+end
diff --git a/noao/digiphot/apphot/daofind/apfdshow.x b/noao/digiphot/apphot/daofind/apfdshow.x
new file mode 100644
index 00000000..61be95ca
--- /dev/null
+++ b/noao/digiphot/apphot/daofind/apfdshow.x
@@ -0,0 +1,72 @@
+include "../lib/apphot.h"
+include "../lib/noise.h"
+include "../lib/find.h"
+
+# AP_FDSHOW -- Display the current find parameters.
+
+procedure ap_fdshow (ap)
+
+pointer	ap	# pointer to the apphot strucuture
+
+begin
+	call ap_nshow (ap)
+	call printf ("\n")
+	call ap_fshow (ap)
+end
+
+
+# AP_FSHOW -- Procedure to display the current data parameters.
+
+procedure ap_fshow (ap)
+
+pointer	ap	# pointer to the apphot strucuture
+
+pointer	sp, str
+bool	itob()
+int	apstati()
+real	apstatr()
+
+begin
+	call smark (sp)
+	call salloc (str, SZ_LINE, TY_CHAR)
+
+	# Set the object charactersitics.
+	call printf ("Kernel Parameters\n")
+	call printf ("    %s = %g %s    %s = %b\n")
+	    call pargstr (KY_FWHMPSF)
+	    call pargr (apstatr (ap, FWHMPSF))
+	    call pargstr (UN_ASCALEUNIT)
+	    call pargstr (KY_POSITIVE)
+	    call pargb (itob (apstati (ap, POSITIVE)))
+
+	call printf ("    %s = %g %s    %s = %g   %s = %g %s\n")
+	    call pargstr (KY_NSIGMA)
+	    call pargr (apstatr (ap, NSIGMA))
+	    call pargstr (UN_FSIGMA)
+	    call pargstr (KY_RATIO)
+	    call pargr (apstatr (ap, RATIO))
+	    call pargstr (KY_THETA)
+	    call pargr (apstatr (ap, THETA))
+	    call pargstr (UN_FDEGREES)
+
+	# Print the rest of the data dependent parameters.
+	call printf ("\nDetection Parameters\n")
+	call printf ("    %s = %g %s\n")
+	    call pargstr (KY_THRESHOLD)
+	    call pargr (apstatr (ap, THRESHOLD))
+	    call pargstr (UN_FSIGMA)
+
+	call printf ("    %s = %g    %s = %g\n")
+	    call pargstr (KY_SHARPLO)
+	    call pargr (apstatr (ap, SHARPLO))
+	    call pargstr (KY_SHARPHI)
+	    call pargr (apstatr (ap, SHARPHI))
+
+	call printf ("    %s = %g    %s = %g\n")
+	    call pargstr (KY_ROUNDLO)
+	    call pargr (apstatr (ap, ROUNDLO))
+	    call pargstr (KY_ROUNDHI)
+	    call pargr (apstatr (ap, ROUNDHI))
+
+	call sfree (sp)
+end
diff --git a/noao/digiphot/apphot/daofind/apfdstars.x b/noao/digiphot/apphot/daofind/apfdstars.x
new file mode 100644
index 00000000..893619f5
--- /dev/null
+++ b/noao/digiphot/apphot/daofind/apfdstars.x
@@ -0,0 +1,151 @@
+include <imhdr.h>
+include <mach.h>
+include "../lib/apphot.h"
+include "../lib/noise.h"
+include "../lib/display.h"
+include "../lib/find.h"
+
+# AP_FDSTARS -- Find stars in an image using a pattern matching technique.
+
+procedure ap_fdstars (im, ap, cnv, sky, out, id, boundary, constant,
+	refit, stid)
+
+pointer	im		# pointer to the input image
+pointer	ap		# pointer to the apphot structure
+pointer	cnv		# pointer to the convolved image
+pointer	sky		# pointer to the sky image
+int	out		# the output file descriptor
+pointer	id		# pointer to image display stream
+int	boundary	# type of boundary extension
+real	constant	# constant for constant boundary extension
+int	refit		# detect stars again
+int	stid		# output file sequence number
+
+int	norm, nxk, nyk, nstars
+pointer	sp, str, gker2d, ngker2d, dker2d, skip
+real	a, b, c, f, skysigma, skymode, threshold, relerr, gsums[LEN_GAUSS]
+real	dmin, dmax, xsigsq, ysigsq
+int	apstati(), ap_find()
+real	ap_egkernel(), apstatr()
+data	gker2d/NULL/, ngker2d/NULL/, dker2d/NULL/ skip /NULL/
+
+define	detect_ 99
+
+begin
+	call smark (sp)
+	call salloc (str, SZ_FNAME, TY_CHAR)
+
+	if (refit == YES)
+	    goto detect_
+
+	# Compute the parameters of the Gaussian kernel.
+	call ap_egparams (FWHM_TO_SIGMA * apstatr (ap, FWHMPSF) * apstatr (ap,
+	    SCALE), apstatr (ap, RATIO), apstatr (ap, THETA), apstatr (ap,
+	    NSIGMA), a, b, c, f, nxk, nyk)
+
+	# Allocate working space.
+	if (gker2d != NULL)
+	    call mfree (gker2d, TY_REAL)
+	call malloc (gker2d, nxk * nyk, TY_REAL)
+	if (ngker2d != NULL)
+	    call mfree (ngker2d, TY_REAL)
+	call malloc (ngker2d, nxk * nyk, TY_REAL)
+	if (dker2d != NULL)
+	    call mfree (dker2d, TY_REAL)
+	call malloc (dker2d, nxk * nyk, TY_REAL)
+	if (skip != NULL)
+	    call mfree (skip, TY_INT)
+	call malloc (skip, nxk * nyk, TY_INT)
+
+	# Compute the 1 and 2 D kernels.
+	if (IS_INDEFR(apstatr(ap, DATAMIN)) && IS_INDEFR(apstatr(ap,
+	    DATAMAX))) {
+	    norm = YES
+	    dmin = -MAX_REAL
+	    dmax = MAX_REAL
+	} else {
+	    norm = NO
+	    if (IS_INDEFR(apstatr (ap, DATAMIN)))
+		dmin = -MAX_REAL
+	    else
+		dmin = apstatr (ap, DATAMIN)
+	    if (IS_INDEFR(apstatr (ap, DATAMAX)))
+		dmax = MAX_REAL
+	    else
+		dmax = apstatr (ap, DATAMAX)
+	}
+	relerr = ap_egkernel (Memr[gker2d], Memr[ngker2d], Memr[dker2d],
+	    Memi[skip], nxk, nyk, gsums, a, b, c, f)
+
+	# Set up the image boundary extension characteristics.
+	call ap_imset (im, boundary, max (1 + nxk / 2, 1 + nyk / 2),
+	    constant)
+	call ap_imset (cnv, boundary, max (1 + nxk / 2, 1 + nyk / 2),
+	    constant)
+
+	# Convolve the input image with the Gaussian kernel. The resultant
+	# picture constains in each pixel the height of the Gaussian
+	# function centered in the subarray which best represents the data
+	# within a circle of nsigma * sigma of the Gaussian.
+
+	if (norm == YES)
+	    call ap_fconvolve (im, cnv, sky, Memr[ngker2d], Memr[dker2d],
+	        Memi[skip], nxk, nyk, gsums[GAUSS_SGOP])
+	else
+	    call ap_gconvolve (im, cnv, sky, Memr[gker2d], Memi[skip],
+	        nxk, nyk, gsums, dmin, dmax)
+
+detect_
+
+	# Write the output header file.
+	if (stid <= 1)
+	    call ap_wfdparam (out, ap)
+
+	call printf ("\nImage: %s  ")
+	    call pargstr (IM_HDRFILE(im))
+	call printf ("fwhmpsf: %g  ratio:  %g  theta:  %g  nsigma: %g\n\n")
+	    call pargr (apstatr (ap, FWHMPSF))
+	    call pargr (apstatr (ap, RATIO))
+	    call pargr (apstatr (ap, THETA))
+	    call pargr (apstatr (ap, NSIGMA))
+
+	# Find all the objects in the input image with the specified image
+	# characteristics.
+
+	skysigma = apstatr (ap, SKYSIGMA)
+	if (IS_INDEFR(skysigma)) {
+	    skymode = 0.0
+	    threshold = 0.0
+	} else {
+	    skymode = apstatr (ap, EPADU) * (skysigma ** 2 - (apstatr (ap,
+	        READNOISE) / apstatr (ap, EPADU)) ** 2) 
+	    skymode = max (0.0, skymode)
+	    threshold = apstatr (ap, THRESHOLD) * skysigma
+	}
+	xsigsq = (apstatr (ap, SCALE) * apstatr (ap, FWHMPSF) / 2.35482) ** 2
+	ysigsq = (apstatr (ap, SCALE) * apstatr (ap, RATIO) *
+	    apstatr (ap, FWHMPSF) / 2.35482) ** 2
+
+	nstars = ap_find (ap, im, cnv, out, id, Memr[gker2d],
+	    Memi[skip], nxk, nyk, skymode, threshold, relerr,
+	    apstati (ap, POSITIVE), xsigsq, ysigsq, dmin, dmax,
+	    apstatr (ap, SHARPLO), apstatr (ap, SHARPHI), apstatr (ap,
+	    ROUNDLO), apstatr (ap, ROUNDHI), YES, stid, apstati (ap,
+	    MKDETECTIONS))
+	stid = stid + nstars
+
+	call printf ("\nthreshold: %g relerr: %5.3f  %g <= sharp <= %g  ")
+	    call pargr (threshold)
+	    call pargr (relerr)
+	    call pargr (apstatr (ap, SHARPLO))
+	    call pargr (apstatr (ap, SHARPHI))
+	call printf ("%g <= round <= %g  \n\n")
+	    call pargr (apstatr (ap, ROUNDLO))
+	    call pargr (apstatr (ap, ROUNDHI))
+
+	call apstats (ap, OUTNAME, Memc[str], SZ_FNAME)
+	call printf ("Output file: %s\n\n")
+	    call pargstr (Memc[str])
+
+	call sfree (sp)
+end
diff --git a/noao/digiphot/apphot/daofind/apfind.x b/noao/digiphot/apphot/daofind/apfind.x
new file mode 100644
index 00000000..1bcbdd52
--- /dev/null
+++ b/noao/digiphot/apphot/daofind/apfind.x
@@ -0,0 +1,626 @@
+include <gset.h>
+include <mach.h>
+include <imhdr.h>
+include "../lib/apphot.h"
+
+# AP_FIND -- Detect images in the convolved image and then compute image
+# characteristics using the original image.
+
+int procedure ap_find (ap, im, cnv, out, id, ker2d, skip, nxk, nyk, skymode,
+	threshold, relerr, emission, xsigsq, ysigsq, datamin, datamax,
+	sharplo, sharphi, roundlo, roundhi, interactive, stid, mkdetections)
+
+pointer ap			# the apphot descriptor
+pointer	im			# pointer to the input image
+pointer	cnv			# pointer to the output image
+int	out			# the output file descriptor
+pointer	id			# pointer to the display stream
+real	ker2d[nxk,ARB]		# 2D Gaussian kernel
+int	skip[nxk,ARB]		# 2D skip kernel
+int	nxk, nyk		# dimensions of the kernel
+real	skymode			# estimate of the sky
+real	threshold		# threshold for image detection
+real	relerr			# the relative error of the convolution kernel
+int	emission		# emission features
+real	xsigsq, ysigsq		# sigma of gaussian in x and y
+real	datamin, datamax	# minimum and maximum good data values
+real	sharplo, sharphi	# sharpness limits
+real	roundlo,roundhi		# roundness parameter limits
+int	interactive		# interactive mode
+int	stid			# sequence number
+int	mkdetections		# mark detections
+
+int	inline, i, j, ncols, col1, col2, line1, line2, index, pos
+int	xmiddle, ymiddle, nonzero, nobjs, nstars, ntotal
+pointer	sp, bufptrs, imlbuf, cnvlbuf, imbuf, cnvbuf, cols
+pointer	satur, sharp, round1, round2, x, y
+
+int	ap_detect(), ap_test(), apstati()
+pointer	imgs2r()
+errchk	imgs2r()
+
+begin
+	# Set up useful line and column limits.
+	ncols = IM_LEN(im,1) + nxk - 1
+	col1 = 1 - nxk / 2
+	col2 = IM_LEN(im,1) + nxk / 2
+	line1 = 1 + nyk / 2
+	line2 = IM_LEN(im,2) + nyk / 2
+	xmiddle = 1 + nxk / 2
+	ymiddle = 1 + nyk / 2
+
+	# Compute find the number of defined elements in the kernel.
+	nonzero = 0
+	#skip[xmiddle,ymiddle] = NO
+	do j = 1, nyk {
+	    do i = 1, nxk {
+		if (skip[i,j] == NO)
+		    nonzero = nonzero + 1
+	    }
+	}
+	skip[xmiddle,ymiddle] = YES
+	nonzero = nonzero - 1
+
+	# Set up a cylindrical buffers and some working space for
+	# the detected images.
+	call smark (sp)
+	call salloc (bufptrs, nyk, TY_INT)
+	call salloc (imbuf, nyk * ncols, TY_REAL)
+	call salloc (cnvbuf, nyk * ncols, TY_REAL)
+	call salloc (cols, ncols, TY_INT)
+	call salloc (satur, ncols, TY_INT)
+	call salloc (sharp, ncols, TY_REAL)
+	call salloc (round1, ncols, TY_REAL)
+	call salloc (round2, ncols, TY_REAL)
+	call salloc (x, ncols, TY_REAL)
+	call salloc (y, ncols, TY_REAL)
+
+	# Read in the first nyk - 1 lines.
+	pos = nyk
+	do inline = 1 - nyk / 2, nyk / 2 {
+	    imlbuf = imgs2r (im, col1, col2, inline, inline)
+	    cnvlbuf = imgs2r (cnv, col1, col2, inline, inline)
+	    if (emission == YES) {
+	        call amovr (Memr[imlbuf], Memr[imbuf+(inline+ymiddle-2)*ncols],
+	            ncols)
+	        call amovr (Memr[cnvlbuf], Memr[cnvbuf+(inline+ymiddle-2)*
+		    ncols], ncols)
+	    } else {
+	        call amulkr (Memr[imlbuf], -1.0, Memr[imbuf+(inline+ymiddle-2)*
+		    ncols], ncols)
+	        call amulkr (Memr[cnvlbuf], -1.0, Memr[cnvbuf+(inline+ymiddle-
+		    2)* ncols], ncols)
+	    }
+	    Memi[bufptrs+pos-1] = pos - 1
+	    pos = pos - 1
+	}
+
+	# Generate the starlist line by line.
+	ntotal = 0
+	pos = nyk
+	do inline = line1, line2 {
+
+	    # Setup the buffer pointer array.
+	    do j = 2, nyk
+		Memi[bufptrs+j-2] = Memi[bufptrs+j-1]
+	    Memi[bufptrs+nyk-1] = pos
+	    index = (pos - 1) * ncols
+
+	    # Read in new image line.
+	    imlbuf = imgs2r (im, col1, col2, inline, inline)
+	    cnvlbuf = imgs2r (cnv, col1, col2, inline, inline)
+
+	    # Copy new lines into cylindrical buffer.
+	    if (emission == YES) {
+	        call amovr (Memr[imlbuf], Memr[imbuf+index], ncols)
+	        call amovr (Memr[cnvlbuf], Memr[cnvbuf+index], ncols)
+	    } else {
+	        call amulkr (Memr[imlbuf], -1.0, Memr[imbuf+index], ncols)
+	        call amulkr (Memr[cnvlbuf], -1.0, Memr[cnvbuf+index], ncols)
+	    }
+
+	    # Detect stars in each image line. In order for a given pixel
+	    # to be detected as an image the pixel must be above threshold
+	    # and be greater than any other pixel within nsigma sigma.
+
+	    # Increment the cylindrical buffer.
+	    if (mod (pos, nyk) == 0)
+		pos = 1
+	    else
+		pos = pos + 1
+
+	    nobjs = ap_detect (Memr[cnvbuf], Memi[bufptrs], ncols, skip, nxk,
+	        nyk, relerr * threshold, Memi[cols])
+	    if (nobjs <= 0)
+		next
+
+	    # Compute the sharpness parameter.
+	    call ap_sharp_round (Memr[imbuf], Memr[cnvbuf], Memi[bufptrs],
+	        ncols, skip, nxk, nyk, Memi[cols], Memi[satur], Memr[round1],
+		Memr[sharp], nobjs, nonzero, skymode, datamin, datamax) 
+
+	    # Compute the roundness parameters.
+	    call ap_xy_round (Memr[imbuf], Memi[bufptrs], ncols, ker2d, nxk,
+	         nyk, Memi[cols], inline, Memr[round2], Memr[x],
+		 Memr[y], nobjs, skymode, datamin, datamax, xsigsq, ysigsq)
+
+	    # Test the image characeteristics of detected objects.
+	    nstars = ap_test (Memi[cols], Memr[x], Memr[y], Memi[satur],
+		Memr[round1], Memr[round2], Memr[sharp], nobjs, IM_LEN(im,1),
+		IM_LEN(im,2), sharplo, sharphi, roundlo, roundhi)
+
+	    # Mark the stars on the display.
+	    if ((nstars > 0) && (interactive == YES) && (id != NULL) &&
+	        (mkdetections == YES)) {
+		call greactivate (id, 0)
+		do j = 1, nstars {
+		    #call ap_ltov (im, Memr[x+j-1], Memr[y+j-1], xc, yc, 1)
+		    #call gmark (id, xc, yc, GM_PLUS, 1.0, 1.0)
+		    call gmark (id, Memr[x+j-1], Memr[y+j-1], GM_PLUS, 1.0, 1.0)
+		}
+		call gdeactivate (id, 0)
+	    }
+
+	    switch (apstati (ap, WCSOUT)) {
+	    case WCS_PHYSICAL:
+		call ap_ltoo (ap, Memr[x], Memr[y], Memr[x], Memr[y], nstars)
+	    case WCS_TV:
+		call ap_ltov (im, Memr[x], Memr[y], Memr[x], Memr[y], nstars)
+	    default:
+		;
+	    }
+
+	    # Print results on the standard output.
+	    if (interactive == YES)
+	        call apstdout (Memr[cnvbuf], Memi[bufptrs], ncols, nyk,
+	            Memi[cols], Memr[x], Memr[y], Memr[sharp], Memr[round1],
+		    Memr[round2], nstars, ntotal, relerr * threshold)
+
+	    # Save the results in the file.
+	    call apdtfout (out, Memr[cnvbuf], Memi[bufptrs], ncols, nyk,
+	        Memi[cols], Memr[x], Memr[y], Memr[sharp], Memr[round1],
+		Memr[round2], nstars, ntotal, relerr * threshold, stid)
+
+
+	    ntotal = ntotal + nstars
+
+	}
+
+	# Free space
+	call sfree (sp)
+
+	return (ntotal)
+end
+
+
+# AP_DETECT -- Detec stellar objects in an image line. In order to be
+# detected as a star the candidate object must be above threshold and have
+# a maximum pixel value greater than any pixels within nsigma * sigma.
+
+int procedure ap_detect (density, ptrs, ncols, skip, nxk, nyk, threshold, cols)
+
+real	density[ncols, ARB]	# density array
+int	ptrs[ARB]		# pointer array
+int	ncols			# x dimesnsion of intensity buffer
+int	skip[nxk,ARB]		# skip array
+int	nxk, nyk		# size of convolution kernel
+real	threshold		# density threshold
+int	cols[ARB]		# column numbers of detected stars
+
+int	i, j, k, kk, middle, nhalf, nobjs
+define	nextpix_	11
+
+begin
+	middle = 1 + nyk / 2
+	nhalf = nxk / 2
+
+	# Loop over all the columns in an image line.
+	nobjs = 0
+	for (i = 1 + nhalf; i <= ncols - nhalf; ) {
+
+	    # Test whether the density enhancement is above threshold.
+	    if (density[i,ptrs[middle]] < threshold)
+		goto nextpix_
+
+	    # Test whether a given density enhancement is a local maximum.
+	    do j = 1, nyk {
+		kk = 1
+	        do k = i - nhalf, i + nhalf {
+		    if (skip[kk,j] == NO) {
+		        if (density[i,ptrs[middle]] < density[k,ptrs[j]])
+		           goto nextpix_
+		    }
+		    kk = kk + 1
+	        }
+	    }
+
+	    # Add the detected object to the list.
+	    nobjs = nobjs + 1
+	    cols[nobjs] = i
+
+	    # If a local maximum is detected there can be no need to
+	    # check pixels in this row between i and i + nhalf.
+	    i = i + nhalf
+nextpix_
+	    # Work on the next pixel.
+	    i = i + 1
+	}
+
+	return (nobjs)
+end
+
+
+# AP_SHARP_ROUND -- Compute an estimate of the roundness and sharpness of the
+# detected objects. The roundness parameter is computed by comparing a measure
+# of the bilateral symmetry with a measure of the four-fold symmetry. The
+# sharpness parameter is defined as the ratio of the difference between the
+# height of the central pixel and the mean of the surrounding pixels to the
+# density enhancement of the central pixel.
+
+procedure ap_sharp_round (data, density, ptrs, ncols, skip, nxk, nyk, cols,
+        satur, round, sharps, nobjs, nonzero, skymode, datamin, datamax) 
+
+real	data[ncols,ARB]		# image data
+real	density[ncols,ARB]	# density enhancements
+int	ptrs[ARB]		# buffer pointers
+int	ncols			# length of data array
+int	skip[nxk,ARB]		# 2D kernel
+int	nxk, nyk		# size of convolution kernel
+int	cols[ARB]		# array of columns
+int	satur[ARB]		# array of saturated state parameters
+real	round[ARB]		# array of roundness parameters
+real	sharps[ARB]		# array of sharpness parameters
+int	nobjs			# number of objects
+int	nonzero			# number of nonzero kernel elements
+real	skymode			# estimate of the sky mode
+real	datamin, datamax	# minimum and maximum good data values
+
+int	i, j, k, xmiddle, ymiddle, npixels, nhalf
+real	pixval, midpix, temp, sharp, sum2, sum4
+
+begin
+	# Loop over the detected objects.
+	nhalf = min (nxk / 2, nyk / 2)
+	xmiddle = 1 + nxk / 2 
+	ymiddle = 1 + nyk / 2
+	do i = 1, nobjs {
+
+	    # Compute the first estimate of roundness.
+	    sum2 = 0.0
+	    sum4 = 0.0
+	    do k = 0, nhalf {
+		do j = 1, nhalf {
+		    sum2 = sum2 +
+		        density[cols[i]-k,ptrs[ymiddle-j]] +
+		        density[cols[i]+k,ptrs[ymiddle+j]] -
+		        density[cols[i]-j,ptrs[ymiddle+k]] -
+		        density[cols[i]+j,ptrs[ymiddle-k]]
+		    sum4 = sum4 +
+		        abs (density[cols[i]-k,ptrs[ymiddle-j]]) +
+		        abs (density[cols[i]+k,ptrs[ymiddle+j]]) +
+		        abs (density[cols[i]-j,ptrs[ymiddle+k]]) +
+		        abs (density[cols[i]+j,ptrs[ymiddle-k]])
+		}
+	    }
+	    if (sum2 == 0.0)
+		round[i] = 0.0
+	    else if (sum4 <= 0.0)
+		round[i] = INDEFR
+	    else
+	        round[i] = 2.0 * sum2 / sum4
+
+	    satur[i] = NO
+
+	    # Eliminate the sharpness test if the central pixel is bad.
+	    midpix = data[cols[i],ptrs[ymiddle]]
+	    if (midpix > datamax) {
+		satur[i] = YES
+		sharps[i] = INDEFR
+		next
+	    }
+	    if (midpix < datamin) {
+		sharps[i] = INDEFR
+		next
+	    }
+
+	    # Accumulate the sharpness statistic.
+	    sharp = 0.0
+	    npixels = nonzero
+	    do j = 1, nyk {
+		temp = 0.0
+	        do k = 1, nxk {
+		    if (skip[k,j] == YES)
+			next
+		    pixval = data[cols[i]-xmiddle+k,ptrs[j]]
+		    if (pixval > datamax) {
+			satur[i] = YES
+			npixels = npixels - 1
+		    } else if (pixval < datamin) {
+			npixels = npixels - 1
+		    } else {
+		        temp = temp + (pixval - skymode)
+		    }
+		}
+		sharp = sharp + temp
+	    }
+
+	    # Compute the sharpness statistic.
+	    if (density[cols[i],ptrs[ymiddle]] <= 0.0 || npixels <= 0)
+		sharps[i] = INDEFR
+	    else
+	        sharps[i] = (midpix - skymode - sharp / real (npixels)) /
+		    density[cols[i],ptrs[ymiddle]]
+
+	}
+end
+
+
+# AP_XY_ROUND -- Estimate the x-y centers and the roundness of the detected
+# objects. The height of the equivalent Gaussian function in x and y is fit by
+# least squares to the marginal distribution of the image data. If either
+# of these of these heights is negative set the roundess characteristic to
+# -MAX_REAL, otherwise compute a roundness characteristic. At the same
+# time setup the necessary sums for computing the first order corection
+# to the centroid of the gaussian profile.
+
+procedure ap_xy_round (data, ptrs, ncols, ker2d, nxk, nyk, cols, inline,
+	rounds, x, y, nobjs, skymode, datamin, datamax, xsigsq, ysigsq)
+
+real	data[ncols,ARB]		# density enhancements
+int	ptrs[ARB]		# buffer pointers
+int	ncols			# number of columns in cylindrical buffer
+real	ker2d[nxk,ARB]		# the gaussian convolution kernel
+int	nxk			# size of kernel in x
+int	nyk			# size of kernel in y
+int	cols[ARB]		# the input positions	
+int	inline			# the input image line
+real	rounds[ARB]		# array of sharpness parameters
+real	x[ARB]			# output x coords
+real	y[ARB]			# output y coords
+int	nobjs			# number of objects
+real	skymode			# estimate of the sky mode
+real	datamin, datamax	# minium and maximum data values
+real	xsigsq, ysigsq		# x-y gaussian sigma squared
+
+int	i, j, k, xmiddle, ymiddle, n
+real	sumgd, sumgsq, sumg, sumd, sumdx, dgdx, sdgdx, sdgdxsq, sddgdx, sgdgdx
+real	pixval, p, sg, sd, wt, hx, hy, dx, dy, skylvl, xhalf, yhalf
+
+begin
+	xhalf = real (nxk / 2) + 0.5
+	yhalf = real (nyk / 2) + 0.5
+	xmiddle = 1 + nxk / 2
+	ymiddle = 1 + nyk / 2
+
+	# Loop over the detected objects.
+	do i = 1, nobjs {
+
+	    # Initialize the x fit.
+	    sumgd = 0.0
+	    sumgsq = 0.0
+	    sumg = 0.0
+	    sumd = 0.0
+	    sumdx = 0.0
+	    sdgdx = 0.0
+	    sdgdxsq = 0.0
+	    sddgdx = 0.0
+	    sgdgdx = 0.0
+	    p = 0.0
+	    n = 0
+
+	    # Compute the sums required for the x fit.
+	    do k = 1, nxk {
+
+		sg = 0.0
+		sd = 0.0
+		do j = 1, nyk {
+		    wt = real (ymiddle - abs (j - ymiddle))
+		    pixval = data[cols[i]-xmiddle+k,ptrs[j]]
+		    if (pixval < datamin || pixval > datamax)
+			next
+		    sd = sd + (pixval - skymode) * wt
+		    sg = sg + ker2d[k,j] * wt
+		}
+
+	        if (sg <= 0.0)
+		    next
+	        wt = real (xmiddle - abs (k - xmiddle))
+	        sumgd = sumgd + wt * sg * sd
+	        sumgsq = sumgsq + wt * sg ** 2
+	        sumg = sumg + wt * sg
+	        sumd = sumd + wt * sd
+		sumdx = sumdx + wt * sd * (xmiddle - k)
+	        p = p + wt
+	        n = n + 1
+	        dgdx = sg * (xmiddle - k)
+	        sdgdxsq = sdgdxsq + wt * dgdx ** 2
+	        sdgdx = sdgdx + wt * dgdx
+	        sddgdx = sddgdx + wt * sd * dgdx
+	        sgdgdx = sgdgdx + wt * sg * dgdx
+	    }
+
+	    # Need at least three points to estimate the x height, position
+	    # and local sky brightness of the star.
+
+	    if (n <= 2 || p <= 0.0) {
+		x[i] = INDEFR
+		y[i] = INDEFR
+		rounds[i] = INDEFR
+		next
+	    }
+
+	    # Solve for the height of the best-fitting gaussian to the
+	    # xmarginal. Reject the star if the height is non-positive.
+
+	    hx = sumgsq - (sumg ** 2) / p
+	    if (hx <= 0.0) {
+		x[i] = INDEFR
+		y[i] = INDEFR
+		rounds[i] = INDEFR
+		next
+	    }
+	    hx = (sumgd - sumg * sumd / p) / hx
+	    if (hx <= 0.0) {
+		x[i] = INDEFR
+		y[i] = INDEFR
+		rounds[i] = INDEFR
+		next
+	    }
+
+	    # Solve for the new x centroid.
+	    skylvl = (sumd - hx * sumg) / p
+	    dx = (sgdgdx - (sddgdx - sdgdx * (hx * sumg + skylvl * p))) /
+		(hx * sdgdxsq / xsigsq)
+	    if (abs (dx) > xhalf) {
+		if (sumd == 0.0)
+		    dx = 0.0
+		else
+		    dx = sumdx / sumd 
+		if (abs (dx) > xhalf)
+		    dx = 0.0
+	    }
+	    x[i] = (cols[i] - xmiddle + 1) + dx 
+
+	    # Initialize y fit.
+	    sumgd = 0.0
+	    sumgsq = 0.0
+	    sumg = 0.0
+	    sumd = 0.0
+	    sumdx = 0.0
+	    sdgdx = 0.0
+	    sdgdxsq = 0.0
+	    sddgdx = 0.0
+	    sgdgdx = 0.0
+	    p = 0.0
+	    n = 0
+
+	    do j = 1, nyk {
+		sg = 0.0
+		sd = 0.0
+		do k = 1, nxk {
+		    wt = real (xmiddle - abs (k - xmiddle))
+		    pixval = data[cols[i]-xmiddle+k,ptrs[j]]
+		    if (pixval < datamin || pixval > datamax)
+			next
+		    sd = sd + (pixval - skymode) * wt
+		    sg = sg + ker2d[k,j] * wt
+		}
+	        if (sg <= 0.0)
+		    next
+	        wt = real (ymiddle - abs (j - ymiddle))
+	        sumgd = sumgd + wt * sg * sd
+	        sumgsq = sumgsq + wt * sg ** 2
+	        sumg = sumg + wt * sg
+	        sumd = sumd + wt * sd
+		sumdx = sumdx + wt * sd * (j - ymiddle)
+	        p = p + wt
+	        n = n + 1
+	        dgdx = sg * (ymiddle - j)
+	        sdgdx = sdgdx + wt * dgdx
+	        sdgdxsq = sdgdxsq + wt * dgdx ** 2
+	        sddgdx = sddgdx + wt * sd * dgdx
+	        sgdgdx = sgdgdx + wt * sg * dgdx
+	    }
+
+	    # Need at least three points to estimate the y height, position
+	    # and local sky brightness of the star.
+
+	    if (n <= 2 || p <= 0.0) {
+		x[i] = INDEFR
+		y[i] = INDEFR
+		rounds[i] = INDEFR
+		next
+	    }
+
+	    # Solve for the height of the best-fitting gaussian to the
+	    # y marginal. Reject the star if the height is non-positive.
+
+	    hy = sumgsq - (sumg ** 2) / p 
+	    if (hy <= 0.0) {
+		x[i] = INDEFR
+		y[i] = INDEFR
+		rounds[i] = INDEFR
+		next
+	    }
+	    hy = (sumgd - sumg * sumd / p) / (sumgsq - (sumg ** 2) / p)
+	    if (hy <= 0.0) {
+		x[i] = INDEFR
+		y[i] = INDEFR
+		rounds[i] = INDEFR
+		next
+	    }
+
+	    # Solve for the new x centroid.
+	    skylvl = (sumd - hy * sumg) / p
+	    dy = (sgdgdx - (sddgdx - sdgdx * (hy * sumg + skylvl * p))) /
+		(hy * sdgdxsq / ysigsq)
+	    if (abs (dy) > yhalf) {
+		if (sumd == 0.0)
+		    dy = 0.0
+		else
+		    dy = sumdx / sumd 
+		if (abs (dy) > yhalf)
+		    dy = 0.0
+	    }
+	    y[i] = (inline - ymiddle + 1) + dy
+
+	    # Compute the roundness.
+	    rounds[i] = 2.0 * (hx - hy) / (hx + hy)
+	}
+end
+
+
+# AP_TEST -- Test the characteristic of the detected images for roundness
+# and sharpness.
+
+int procedure ap_test (cols, x, y, satur, round1, round2, sharps, nobjs,
+	ncols, nlines, sharplo, sharphi, roundlo, roundhi)
+
+int	cols[ARB]			# col IDS of detected images
+real	x[ARB]				# x positions
+real	y[ARB]				# y positions
+int	satur[ARB]			# saturation condition
+real	round1[ARB]			# first roundness parameters
+real	round2[ARB]			# second roundness parameters
+real	sharps[ARB]			# sharpness parameters
+int	nobjs				# number of objects
+int	ncols, nlines			# size of the input image
+real	sharplo, sharphi		# sharpness parameters
+real	roundlo, roundhi		# roundness parameters
+
+int	i, nstars
+
+begin
+	# Loop over the detected objects.
+	nstars = 0
+	do i = 1, nobjs {
+
+	    # Compute the sharpness statistic
+	    if (! IS_INDEFR(sharps[i]) && (sharps[i] < sharplo ||
+	        sharps[i] > sharphi))
+		next
+	    if (IS_INDEFR(round1[i]) || round1[i] < roundlo ||
+	        round1[i] > roundhi)
+		next
+	    if (satur[i] == NO) {
+	        if (IS_INDEFR(round2[i]) || round2[i] < roundlo ||
+	            round2[i] > roundhi)
+		next
+	    }
+	    if (IS_INDEFR(x[i]) || x[i] < 0.5 || x[i] > (ncols+0.5))
+		next
+	    if (IS_INDEFR(y[i]) || y[i] < 0.5 || y[i] > (nlines+0.5))
+		next
+
+	    # Add object to the list.
+	    nstars = nstars + 1
+	    cols[nstars] = cols[i]
+	    x[nstars] = x[i]
+	    y[nstars] = y[i]
+	    sharps[nstars] = sharps[i]
+	    round1[nstars] = round1[i]
+	    round2[nstars] = round2[i]
+	}
+
+	return (nstars)
+end
diff --git a/noao/digiphot/apphot/daofind/apimset.x b/noao/digiphot/apphot/daofind/apimset.x
new file mode 100644
index 00000000..6f1e8cdc
--- /dev/null
+++ b/noao/digiphot/apphot/daofind/apimset.x
@@ -0,0 +1,17 @@
+include <imset.h>
+
+# AP_IMSET -- Setup image boundary extension charactersitics.
+
+procedure ap_imset (im, boundary, npix, constant)
+
+pointer	im		# pointer to the image
+int	boundary	# type of boundary condition
+int	npix		# number of pixels of boundary entension
+real	constant	# constant for constant boundary extension
+
+begin
+	call imseti (im, IM_TYBNDRY, boundary)
+	call imseti (im, IM_NBNDRYPIX, npix)
+	if (boundary == BT_CONSTANT)
+	    call imsetr (im, IM_BNDRYPIXVAL, constant)
+end
diff --git a/noao/digiphot/apphot/daofind/daofind.key b/noao/digiphot/apphot/daofind/daofind.key
new file mode 100644
index 00000000..e68ceb80
--- /dev/null
+++ b/noao/digiphot/apphot/daofind/daofind.key
@@ -0,0 +1,66 @@
+	     Interactive Keystroke Commands
+
+?	Print help
+:	Colon commands 
+v	Verify the critical parameters
+w	Save the current parameters
+d	Plot radial profile of star near cursor
+i	Interactively set parameters using star near cursor
+f	Find stars in the image
+spbar	Find stars in the image, output results
+q	Exit task
+
+
+		Colon Commands
+
+:show		[data/center]	List the parameters
+
+		Colon Parameter Editing Commands
+
+# Image and file name parameters
+
+:image		[string]	Image name
+:output		[string]	Output file name
+
+# Data dependent parameters
+
+:scale		[value]		Image scale (units per pixel)
+:fwhmpsf	[value]		Full width half maximum of psf (scale units)
+:emission	[y/n]		Emission feature (y), absorption (n)
+:sigma		[value]		Standard deviation of sky (counts)
+:datamin	[value]		Minimum good data value (counts)
+:datamax	[value]		Maximum good data value (counts)
+
+# Noise description parameters
+
+:noise 		[string]	Noise model (constant|poisson)
+:gain		[string]	Gain image header keyword
+:ccdread	[string]	Readout noise image header keyword
+:epadu		[value]		Gain (electrons per adu)
+:readnoise	[value]		Readout noise (electrons)
+
+# Observation parameters
+
+:exposure	[string]	Exposure time image header keyword
+:airmass	[string]	Airmass image header keyword
+:filter		[string]	Filter image header keyword
+:obstime	[string]	Time of observation image header keyword
+:itime		[value]		Exposure time (time units)
+:xairmass	[value]		Airmass value (number)
+:ifilter	[string]	Filter id string
+:otime		[string]	Time of observation (time units)
+
+# Object detection parameters
+
+:nsigma		[value]		Size of Gaussian kernel (sigma) 
+:threshold	[value]		Detection intensity threshold (counts)
+:ratio		[value]		Sigmay / sigmax of Gaussian kernel
+:theta		[value]		Position angle of Gaussian kernel
+:sharplo	[value]		Lower bound on sharpness
+:sharphi	[value]		Upper bound on sharpness
+:roundlo	[value]		Lower bound on roundness
+:roundhi	[value]		Upper bound on roundness
+
+# Plotting and marking commands
+
+:mkdetections	[y/n]		Mark detections on the image display
diff --git a/noao/digiphot/apphot/daofind/idaofind.key b/noao/digiphot/apphot/daofind/idaofind.key
new file mode 100644
index 00000000..7da8fe42
--- /dev/null
+++ b/noao/digiphot/apphot/daofind/idaofind.key
@@ -0,0 +1,8 @@
+                    Interactive Daofind Setup Menu
+
+	v	Mark and verify critical daofind parameters (f,s)
+
+	f	Mark and verify the full-width half-maximum of the psf
+	s	Mark and verify the standard deviation of the background
+	l	Mark and verify the minimum good data value
+	u	Mark and verify the maximum good data value
diff --git a/noao/digiphot/apphot/daofind/mkpkg b/noao/digiphot/apphot/daofind/mkpkg
new file mode 100644
index 00000000..28935c11
--- /dev/null
+++ b/noao/digiphot/apphot/daofind/mkpkg
@@ -0,0 +1,37 @@
+# DAOFIND task
+
+$checkout libpkg.a ".."
+$update libpkg.a
+$checkin libpkg.a ".."
+$exit
+
+libpkg.a:
+	apbfdfind.x	<imhdr.h>		<mach.h>                \
+			<imio.h>		"../lib/apphot.h"	\
+			"../lib/noise.h"	"../lib/find.h"
+	apconvolve.x	<imhdr.h>		<imset.h>               \
+			"../lib/find.h"
+	apegkernel.x	<math.h>		"../lib/find.h"
+	apfdcolon.x	"../lib/apphot.h"	"../lib/noise.h"	\
+			"../lib/find.h"         "../lib/display.h"
+	apfdconfirm.x	
+	apfdfind.x	"../lib/apphot.h"	"../lib/display.h"	\
+			"../lib/find.h"         <imhdr.h>
+	apfdfree.x	"../lib/apphotdef.h"
+	apfdgpars.x	"../lib/noise.h"	"../lib/display.h"
+	apfdinit.x	"../lib/apphotdef.h"	"../lib/finddef.h"
+	apfdpars.x	"../lib/display.h"
+	apfdradsetup.x	
+	apfdshow.x	"../lib/apphot.h"	"../lib/noise.h"        \
+			"../lib/find.h"
+	apfdstars.x	<imhdr.h>		<mach.h>                \
+			"../lib/apphot.h"	"../lib/noise.h"	\
+			"../lib/find.h"		"../lib/display.h"
+	apfind.x	<imhdr.h>		<mach.h>                \
+			<gset.h>		"../lib/apphot.h"
+	apimset.x	<imset.h>
+	t_daofind.x	<fset.h> 		 <imhdr.h>		\
+			<gset.h>		"../lib/apphot.h"	\
+			"../lib/noise.h"	"../lib/find.h"         \
+			<imhdr.h>
+	;
diff --git a/noao/digiphot/apphot/daofind/t_daofind.x b/noao/digiphot/apphot/daofind/t_daofind.x
new file mode 100644
index 00000000..eaf77fbf
--- /dev/null
+++ b/noao/digiphot/apphot/daofind/t_daofind.x
@@ -0,0 +1,419 @@
+include <imhdr.h>
+include <gset.h>
+include <fset.h>
+include <imhdr.h>
+include "../lib/apphot.h"
+include "../lib/noise.h"
+include "../lib/find.h"
+
+# T_DAOFIND --  Automatically detect objects in an image given the full
+# width half maximum of the image point spread function and a detection
+# threshold.
+
+procedure t_daofind ()
+
+pointer	image			# pointer to input image
+pointer denimage		# pointer to density enhancement image
+pointer	skyimage		# pointer to the sky image
+int	output			# the results file descriptor
+int	boundary		# type of boundary extension
+real	constant		# constant for constant boundary extension
+int	interactive		# interactive mode
+int	verify			# verify mode
+int	update			# update critical parameters
+int	verbose			# verbose mode
+int	cache			# cache the image pixels
+
+pointer	im, cnv, sky, sp, outfname, denname, skyname, str
+pointer	ap, cname, display, graphics, id, gd
+int	limlist, lolist, densave, skysave, out, root, stat, imlist, olist
+int	wcs, req_size, old_size, buf_size, memstat
+
+real	clgetr()
+pointer	gopen(), immap(), ap_immap()
+int	imtlen(), clplen(), btoi(), clgwrd(), aptmpimage()
+int	open(), strncmp(), strlen(), fnldir(), ap_fdfind()
+int	imtopenp(), clpopnu(), clgfil(), imtgetim(), ap_memstat(), sizeof()
+bool	clgetb(), streq()
+
+begin
+	# Flush STDOUT on a new line.
+	call fseti (STDOUT, F_FLUSHNL, YES)
+
+	# Allocate working space.
+	call smark (sp)
+	call salloc (image, SZ_FNAME, TY_CHAR)
+	call salloc (output, SZ_FNAME, TY_CHAR)
+	call salloc (denimage, SZ_FNAME, TY_CHAR)
+	call salloc (skyimage, SZ_FNAME, TY_CHAR)
+	call salloc (display, SZ_FNAME, TY_CHAR)
+	call salloc (graphics, SZ_FNAME, TY_CHAR)
+
+	call salloc (outfname, SZ_FNAME, TY_CHAR)
+	call salloc (denname, SZ_FNAME, TY_CHAR)
+	call salloc (skyname, SZ_FNAME, TY_CHAR)
+	call salloc (cname, SZ_FNAME, TY_CHAR)
+	call salloc (str, SZ_LINE, TY_CHAR)
+
+	# Fetch the image and output file lists.
+	imlist = imtopenp ("image")
+	limlist = imtlen (imlist)
+	olist = clpopnu ("output")
+	lolist = clplen (olist)
+
+	# Get prefix for density enhancement and sky images.
+	call clgstr ("starmap", Memc[denimage], SZ_FNAME)
+	call clgstr ("skymap", Memc[skyimage], SZ_FNAME)
+
+	# Get the image boundary extensions parameters.
+	boundary = clgwrd ("boundary", Memc[str], SZ_LINE,
+	    ",constant,nearest,reflect,wrap,")
+	constant = clgetr ("constant")
+
+	call clgstr ("icommands.p_filename", Memc[cname], SZ_FNAME)
+	if (Memc[cname] != EOS)
+	    interactive = NO
+	else
+	    interactive = btoi (clgetb ("interactive"))
+	verbose = btoi (clgetb ("verbose"))
+	verify = btoi (clgetb ("verify"))
+	update = btoi (clgetb ("update"))
+	cache = btoi (clgetb ("cache"))
+
+	# Get the parameters.
+	call ap_fdgpars (ap)
+
+	# Confirm the algorithm parameters.
+	if (verify == YES && interactive == NO)  {
+	    call ap_fdconfirm (ap)
+	    if (update == YES)
+		call ap_fdpars (ap)
+	}
+
+	# Get the wcs info.
+	wcs = clgwrd ("wcsout", Memc[str], SZ_LINE, WCSOUTSTR)
+	if (wcs <= 0) {
+	    call eprintf (
+	        "Warning: Setting the output coordinate system to logical\n")
+	    wcs = WCS_LOGICAL
+	}
+	call apseti (ap, WCSOUT, wcs)
+
+	# Get the graphics and display devices.
+	call clgstr ("graphics", Memc[graphics], SZ_FNAME)
+	call clgstr ("display", Memc[display], SZ_FNAME)
+
+	# Open the graphics and display devices.
+	if (interactive == YES) {
+	    if (Memc[graphics] == EOS)
+		gd = NULL
+	    else {
+		iferr {
+		    gd =  gopen (Memc[graphics], APPEND+AW_DEFER, STDGRAPH)
+		} then {
+		    call eprintf (
+			"Warning: Error opening the graphics device.\n")
+		    gd = NULL
+		}
+	    }
+	    if (Memc[display] == EOS)
+		id = NULL
+	    else if (streq (Memc[graphics], Memc[display]))
+		id = gd
+	    else {
+		iferr {
+		    id = gopen (Memc[display], APPEND, STDIMAGE)
+		} then {
+		    call eprintf (
+		"Warning: Graphics overlay not available for display device.\n")
+		    id = NULL
+		}
+	    }
+	} else {
+	    gd = NULL
+	    id = NULL
+	}
+
+	# Loop over the images.
+	while (imtgetim (imlist, Memc[image], SZ_FNAME) != EOF) {
+
+	    # Open the image and get the required keywords from the header.
+
+	    im = immap (Memc[image], READ_ONLY, 0)
+	    call apimkeys (ap, im, Memc[image])
+
+	    # Set the image display viewport.
+	    if ((id != NULL) && (id != gd))
+		call ap_gswv (id, Memc[image], im, 4)
+
+	    # Cache the input image pixels.
+            req_size = MEMFUDGE * (IM_LEN(im,1) * IM_LEN(im,2) *
+                sizeof (IM_PIXTYPE(im)) + 2 * IM_LEN(im,1) * IM_LEN(im,2) *
+		sizeof (TY_REAL))
+            memstat = ap_memstat (cache, req_size, old_size)
+            if (memstat == YES)
+                call ap_pcache (im, INDEFI, buf_size)
+
+	    # Determine the results file name. If output is a null string or
+	    # a directory name then the extension "coo" is added to the
+	    # root image name and the appropriate version number is appended
+	    # in order to construct a default output file name.
+
+	    out = NULL
+	    if (lolist == 0) {
+		call strcpy ("", Memc[outfname], SZ_FNAME)
+	    } else {
+	        stat = clgfil (olist, Memc[output], SZ_FNAME)
+		root = fnldir (Memc[output], Memc[outfname], SZ_FNAME)
+		if (strncmp ("default", Memc[output+root], 7) == 0 || root ==
+		    strlen (Memc[output])) {
+	            call apoutname (Memc[image], Memc[outfname], "coo",
+		        Memc[outfname], SZ_FNAME)
+		    lolist = limlist
+		} else if (stat != EOF) {
+		    call strcpy (Memc[output], Memc[outfname], SZ_FNAME)
+		} else {
+	            call apoutname (Memc[image], Memc[outfname], "coo",
+		        Memc[outfname], SZ_FNAME)
+		    lolist = limlist
+		}
+	    }
+	    call apsets (ap, OUTNAME, Memc[outfname])
+
+	    # Set up the directory and name for the density enhancement image.
+	    # Note that the default value for denimage is the null string
+	    # indicating the current directory. If denimage is null or
+	    # contains only a directory specification make a temporary image
+	    # name using the prefix "den", otherwise use the user specified
+	    # prefix.
+
+	    densave = aptmpimage (Memc[image], Memc[denimage], "den",
+	        Memc[denname], SZ_FNAME)
+
+	    # Set up the directory and name for the sky values image. 
+
+	    skysave = aptmpimage (Memc[image], Memc[skyimage], "sky",
+	        Memc[skyname], SZ_FNAME)
+
+	    # Find the stars in an image.
+	    if (interactive == NO) {
+
+		cnv = NULL
+		if (Memc[cname] != EOS) {
+		    stat = ap_fdfind (Memc[denname], Memc[skyname], ap, im,
+		        NULL, NULL, out, boundary, constant, densave,
+			skysave, NO, cache)
+		} else {
+	            cnv = ap_immap (Memc[denname], im, ap, densave)
+                    if (memstat == YES)
+                	call ap_pcache (cnv, INDEFI, buf_size)
+		    if (skysave == YES) {
+			sky = ap_immap (Memc[skyname], im, ap, skysave)
+                        if (memstat == YES)
+                	    call ap_pcache (sky, INDEFI, buf_size)
+		    } else
+			sky = NULL
+		    if (Memc[outfname] != EOS)
+		        out = open (Memc[outfname], NEW_FILE, TEXT_FILE)
+		    else
+			out = NULL
+		    call ap_bfdfind (im, cnv, sky, out, ap, boundary,
+		        constant, verbose)
+	            call imunmap (cnv)
+		    if (sky != NULL)
+			call imunmap (sky)
+	            if (densave == NO)
+	                call imdelete (Memc[denname])
+		    stat = NO
+		}
+
+	    } else
+		stat = ap_fdfind (Memc[denname], Memc[skyname], ap, im, gd,
+		    id, out, boundary, constant, densave, skysave, YES,
+		    cache)
+
+	    # Clean up files.
+	    call imunmap (im)
+	    call close (out)
+
+	    # Uncache memory
+	    call fixmem (old_size)
+
+	    if (stat == YES)
+		break
+	}
+
+	# Close up the graphics system.
+	if (id == gd && id != NULL)
+	    call gclose (id)
+	else {
+	    if (gd != NULL)
+	        call gclose (gd)
+	    if (id != NULL)
+	        call gclose (id)
+	}
+
+	# Close image and output file lists.
+	call ap_fdfree (ap)
+	call imtclose (imlist)
+	call clpcls (olist)
+	call sfree (sp)
+end
+
+
+# AP_IMMAP -- Map the output image.
+
+pointer procedure ap_immap (outname, im, ap, save)
+
+char	outname[ARB]		# convolved image name
+pointer	im			# pointer to input image
+pointer	ap			# pointer to the apphot structure
+int	save			# save the convolved image
+
+int	newimage
+pointer	outim
+real	tmp_scale, tmp_fwhmpsf, tmp_ratio, tmp_theta, tmp_nsigma
+real	tmp_datamin, tmp_datamax
+bool	fp_equalr()
+int	imaccess()
+pointer	immap()
+real	apstatr(), imgetr()
+errchk	imgetr()
+
+begin
+	# Check to see if the image already exists. If it does not
+	# open a new image and write the PSF characteristics into the
+	# image user area, otherwise fetch the PSF parameters from the image
+	# header.
+
+	if (save == NO || imaccess (outname, READ_ONLY) == NO) {
+
+	    outim = immap (outname, NEW_COPY, im)
+	    IM_PIXTYPE(outim) = TY_REAL
+	    call imaddr (outim, "SCALE", 1.0 / apstatr (ap, SCALE))
+	    call imaddr (outim, "FWHMPSF", apstatr (ap, FWHMPSF))
+	    call imaddr (outim, "NSIGMA", apstatr (ap, NSIGMA))
+	    call imaddr (outim, "RATIO", apstatr (ap, RATIO))
+	    call imaddr (outim, "THETA", apstatr (ap, THETA))
+	    call imaddr (outim, "DATAMIN", apstatr (ap, DATAMIN))
+	    call imaddr (outim, "DATAMAX", apstatr (ap, DATAMIN))
+
+	} else {
+
+	    outim = immap (outname, READ_ONLY, 0)
+	    iferr (tmp_scale = 1.0 / imgetr (outim, "SCALE"))
+		tmp_scale = INDEFR
+	    iferr (tmp_fwhmpsf = imgetr (outim, "FWHMPSF"))
+		tmp_fwhmpsf = INDEFR
+	    iferr (tmp_nsigma = imgetr (outim, "NSIGMA"))
+		tmp_nsigma = INDEFR
+	    iferr (tmp_ratio = imgetr (outim, "RATIO"))
+		tmp_ratio = INDEFR
+	    iferr (tmp_theta = imgetr (outim, "THETA"))
+		tmp_theta = INDEFR
+	    iferr (tmp_datamin = imgetr (outim, "DATAMIN"))
+		tmp_datamin = INDEFR
+	    iferr (tmp_datamax = imgetr (outim, "DATAMAX"))
+		tmp_datamax = INDEFR
+
+	    if (IS_INDEFR(tmp_scale) || ! fp_equalr (tmp_scale, apstatr (ap,
+	        SCALE)))
+		newimage = YES
+	    else if (IS_INDEFR(tmp_fwhmpsf) || ! fp_equalr (tmp_fwhmpsf,
+	        apstatr (ap, FWHMPSF)))
+		newimage = YES
+	    else if (IS_INDEFR(tmp_nsigma) || ! fp_equalr (tmp_nsigma,
+	        apstatr (ap, NSIGMA)))
+		newimage = YES
+	    else if (IS_INDEFR(tmp_ratio) || ! fp_equalr (tmp_ratio,
+	        apstatr (ap, RATIO)))
+		newimage = YES
+	    else if (IS_INDEFR(tmp_theta) || ! fp_equalr (tmp_theta,
+	        apstatr (ap, THETA)))
+		newimage = YES
+	    else if (IS_INDEFR(tmp_datamin) || ! fp_equalr (tmp_datamin,
+	        apstatr (ap, DATAMIN)))
+		newimage = YES
+	    else if (IS_INDEFR(tmp_datamax) || ! fp_equalr (tmp_datamax,
+	        apstatr (ap, DATAMAX)))
+		newimage = YES
+	    else
+		newimage = NO
+
+	    if (newimage == YES) {
+		call imunmap (outim)
+		call imdelete (outname)
+	        outim = immap (outname, NEW_COPY, im)
+		IM_PIXTYPE(outim) = TY_REAL
+	        call imaddr (outim, "SCALE", 1.0 / apstatr (ap, SCALE))
+	        call imaddr (outim, "FWHMPSF", apstatr (ap, FWHMPSF))
+	        call imaddr (outim, "NSIGMA", apstatr (ap, NSIGMA))
+	        call imaddr (outim, "RATIO", apstatr (ap, RATIO))
+	        call imaddr (outim, "THETA", apstatr (ap, THETA))
+	    }
+	}
+
+	return (outim)
+end
+
+
+# AP_OUTMAP -- Manufacture an output coordinate file name.
+
+procedure ap_outmap (ap, out, root)
+
+pointer	ap		# pointer to the apphot structure
+int	out		# the output file descriptor
+char	root[ARB]	# root of the previous output file name, may be
+			# updated
+
+int	findex, lindex, version
+pointer	sp, image, outname, newoutname
+int	strmatch(), gstrmatch(), open(), fnldir(), access()
+
+begin
+	if (out != NULL)
+	    call close (out)
+
+	call smark (sp)
+	call salloc (image, SZ_FNAME, TY_CHAR)
+	call salloc (outname, SZ_FNAME, TY_CHAR)
+	call salloc (newoutname, SZ_FNAME, TY_CHAR)
+
+	# Get the old names.
+	call apstats (ap, IMNAME, Memc[image], SZ_FNAME)
+	call apstats (ap, OUTNAME, Memc[outname], SZ_FNAME)
+
+	# Manufacture a new name. Search first for existing files with
+	# the form "outname.coo.*" and create a new version number.
+	# If the first search fails look for names containing root
+	# and append a version number to create a new output file
+	# name. Otherwise simply use the output name.
+
+	if (Memc[outname] == EOS) {
+	    Memc[newoutname] = EOS
+        } else if (strmatch (Memc[outname], "\.coo\.") > 0) {
+	    findex = fnldir (Memc[outname], Memc[newoutname], SZ_FNAME)
+	    call apoutname (Memc[image], Memc[newoutname], "coo",
+	        Memc[newoutname], SZ_FNAME)
+	} else if (gstrmatch (Memc[outname], root, findex, lindex) > 0) {
+	    repeat {
+	        version = version + 1
+	        call strcpy (Memc[outname], Memc[newoutname], SZ_FNAME)
+	        call sprintf (Memc[newoutname+lindex], SZ_FNAME, ".%d")
+		    call pargi (version)
+	    } until (access (Memc[newoutname], 0, 0) == NO)
+	} else {
+	    version = 1
+	    call strcpy (Memc[outname], root, SZ_FNAME)
+	    call strcpy (Memc[outname], Memc[newoutname], SZ_FNAME)
+	}
+
+	# Open the output image.
+	if (Memc[newoutname] == EOS)
+	    out = NULL
+	else
+	    out = open (Memc[newoutname], NEW_FILE, TEXT_FILE)
+	call apsets (ap, OUTNAME, Memc[newoutname])
+
+	call sfree (sp)
+end
diff --git a/noao/digiphot/apphot/datapars.par b/noao/digiphot/apphot/datapars.par
new file mode 100644
index 00000000..15778b9f
--- /dev/null
+++ b/noao/digiphot/apphot/datapars.par
@@ -0,0 +1,25 @@
+# DATAPARS
+
+scale,r,h,1.0,0.0,,Image scale in units per pixel
+fwhmpsf,r,h,2.5,0.0,,FWHM of the PSF in scale units
+emission,b,h,y,,,Features are positive ?
+sigma,r,h,INDEF,,,Standard deviation of background in counts
+datamin,r,h,INDEF,,,Minimum good data value
+datamax,r,h,INDEF,,,Maximum good data value
+
+noise,s,h,"poisson","|constant|poisson|",,Noise model
+ccdread,s,h,"",,,CCD readout noise image header keyword
+gain,s,h,"",,,CCD gain image header keyword
+readnoise,r,h,0.0,,,CCD readout noise in electrons
+epadu,r,h,1.0,,,Gain in electrons per count
+
+exposure,s,h,"",,,Exposure time image header keyword
+airmass,s,h,"",,,Airmass image header keyword
+filter,s,h,"",,,Filter image header keyword
+obstime,s,h,"",,,Time of observation image header keyword
+itime,r,h,1.0,,,Exposure time
+xairmass,r,h,INDEF,,,Airmass
+ifilter,s,h,"INDEF",,,Filter
+otime,s,h,"INDEF",,,Time of observation
+
+mode,s,h,'ql'
diff --git a/noao/digiphot/apphot/doc/apsums.apps b/noao/digiphot/apphot/doc/apsums.apps
new file mode 100644
index 00000000..ea5843bf
--- /dev/null
+++ b/noao/digiphot/apphot/doc/apsums.apps
@@ -0,0 +1,19 @@
+The apphot and daophot package aperture photometry tasks have been modified
+to compute the aperture sums and areas in double precision instead of real
+precision.  This change minimizes machine precision errors that can become
+significant for large apertures and very low noise or synthetic data.
+
+These tasks have also been modified to output negative values of the total
+flux should they occur. Formerly these values were being artificially set to 
+0.0. This change makes it easier to see the effects of any sky value and machine
+errors.
+
+The modified apertures photometry tasks are available as part of the
+external addon package digiphotx.  To retrieve and install digiphotx, ftp
+to 140.252.1.1, login as anonymous, cd to iraf/extern, retrieve the file
+digiphotx.readme, and follow the installation instructions.
+
+
+
+					      Lindsey Davis
+					      davis@noao.edu
diff --git a/noao/digiphot/apphot/doc/apsums.noao b/noao/digiphot/apphot/doc/apsums.noao
new file mode 100644
index 00000000..fd920b49
--- /dev/null
+++ b/noao/digiphot/apphot/doc/apsums.noao
@@ -0,0 +1,17 @@
+The apphot and daophot package aperture photometry tasks have been modified
+to compute the aperture sums and areas in double precision instead of real
+precision.  This change minimizes machine precision errors that can become
+significant for large apertures and very low noise or synthetic data.
+
+These tasks have also been modified to output negative values of the total
+flux should they occur. Formerly these values were being artificially set to 
+0.0. This change makes it easier to see the effects of any sky value and machine
+errors.
+
+The modified apertures photometry tasks are available under irafx. Let me
+know if you have any questions about the modified tasks or encounter and
+problems using them.
+
+
+					      Lindsey Davis
+					      davis@noao.edu
diff --git a/noao/digiphot/apphot/doc/aptest.hlp b/noao/digiphot/apphot/doc/aptest.hlp
new file mode 100644
index 00000000..85fad0d9
--- /dev/null
+++ b/noao/digiphot/apphot/doc/aptest.hlp
@@ -0,0 +1,68 @@
+.help aptest Dec92 noao.digiphot.apphot
+.ih
+NAME
+aptest -- run basic tests on the apphot package tasks
+.ih
+USAGE
+aptest imname
+.ih
+PARAMETERS
+.ls imname
+The name of the output test image. The actual test image is stored in fits
+format in the APPHOT package subdirectory test. If the image already exists
+APTEST will exit with a warning message.
+.le
+.ls aplogfile = ""
+The name of the output log file. By default all the text output is logged
+in a file called \fI"imname.log"\fR. If the log file already exists APTEST will
+exit with a warning message.
+.le
+.ls applotfile = ""
+The name of the output log file. By default all the plot output is logged in
+a file called \fI"imname.plot"\fR. If the plot file already exists APTEST will
+exit with a warning message.
+.le
+.ih
+DESCRIPTION
+APTEST is a simple script which exercises each of the tasks in the APPHOT
+package in turn. At startup APTEST reads a small fits image stored in the
+APPHOT test subdirectory and creates the image \fIimname\fR in the user's
+working directory. APTEST initializes the APPHOT package by returning
+all the parameters to their default state, runs each of the APPHOT
+tasks in non-interactive mode, spools the text output to the file
+\fIaplogfile\fR, and spools the plot output from the RADPROF task to the plot
+metacode file \fIapplotfile\fR.
+.ih
+EXAMPLES
+
+1. Check to see that all the APPHOT tasks are functioning correctly.
+
+.nf
+	ap> apphot
+
+	... load the apphot package
+
+	ap> aptest testim
+
+	... run the test script
+
+	ap> lprint testim.log
+
+	... print the text output
+
+	ap> gkidir testim.plot
+
+	... list the contents of the plot file
+
+	ap> gkiextract testim.plot 1-N | stdplot
+
+	... send the plots to the plotter
+.fi
+
+.ih
+TIME REQUIREMENTS
+.ih
+BUGS
+.ih
+SEE ALSO
+.endhelp
diff --git a/noao/digiphot/apphot/doc/center.hlp b/noao/digiphot/apphot/doc/center.hlp
new file mode 100644
index 00000000..c409c49b
--- /dev/null
+++ b/noao/digiphot/apphot/doc/center.hlp
@@ -0,0 +1,638 @@
+.help center May00 noao.digiphot.apphot
+.ih
+NAME
+center -- compute accurate centers for a list of objects
+.ih
+USAGE
+center image
+.ih
+PARAMETERS
+.ls image
+The list of images containing the objects to be centered.
+.le
+.ls coords = ""
+The list of text files containing initial coordinates for the objects to
+be centered. Objects are listed in coords one object per line with the
+initial coordinate values in columns one and two. The number of coordinate
+files must be zero, one, or equal to the number of images.
+If coords is "default", "dir$default", or a directory specification then an
+coords file name of the form dir$root.extension.version is constructed and
+searched for, where dir is the directory, root is the root image name,
+extension is "coo" and version is the next available version number for the
+file.
+.le
+.ls output = "default"
+The name of the results file or results directory. If output is
+"default", "dir$default", or a directory specification then an output file name
+of the form dir$root.extension.version is constructed, where dir is the
+directory, root is the root image name, extension is "ctr" and version is
+the next available version number for the file. The number of output files
+must be zero, one, or equal to the number of image files.  In both interactive
+and batch mode full output is written to output. In interactive mode
+an output summary is also written to the standard output.
+.le
+.ls plotfile = ""
+The name of the file containing radial profile plots of the stars written
+to the output file. If plotfile is defined then a radial profile plot
+is written to plotfile every time a record is written to \fIoutput\fR.
+The user should be aware that this can be a time consuming operation.
+.le
+.ls datapars = ""
+The name of the file containing the data dependent parameters.
+The critical parameters \fIfwhmpsf\fR and \fIsigma\fR are located in
+datapars.  If datapars is undefined then the default parameter set in 
+uparm directory is used.
+.le
+.ls centerpars = ""
+The name of the file containing the centering algorithm parameters.
+The critical parameters \fIcalgorithm\fR and \fIcbox\fR are located in
+centerpars. If centerpars is undefined then the default parameter
+set in uparm is used.
+.le
+.ls interactive = yes
+Interactive or non-interactive mode?
+.le
+.ls radplots = no
+If \fIradplots\fR is "yes" and CENTER is run in interactive mode, a radial
+profile of each star is plotted on the screen after the center is fit.
+.le
+.ls icommands = ""
+The image display cursor or image cursor command file. 
+.le
+.ls gcommands = ""
+The graphics cursor or graphics cursor command file.
+.le
+.ls wcsin = ")_.wcsin", wcsout = ")_.wcsout"
+The coordinate system of the input coordinates read from \fIcoords\fR and
+of the output coordinates written to \fIoutput\fR respectively. The image
+header coordinate system is used to transform from the input coordinate
+system to the "logical" pixel coordinate system used internally,
+and from the internal "logical" pixel coordinate system to the output
+coordinate system. The input coordinate system options are "logical", tv",
+"physical", and "world". The output coordinate system options are "logical",
+"tv", and "physical". The image cursor coordinate system is assumed to
+be the "tv" system.
+.ls logical
+Logical coordinates are pixel coordinates relative to the current image.
+The  logical coordinate system is the coordinate system used by the image
+input/output routines to access the image data on disk. In the logical
+coordinate system the coordinates of the first pixel of a  2D image, e.g.
+dev$ypix  and a 2D image section, e.g. dev$ypix[200:300,200:300] are
+always (1,1).
+.le
+.ls tv  
+Tv coordinates are the pixel coordinates used by the display servers. Tv
+coordinates  include  the effects of any input image section, but do not
+include the effects of previous linear transformations. If the input
+image name does not include an image section, then tv coordinates are
+identical to logical coordinates.  If the input image name does include a
+section, and the input image has not been linearly transformed or copied from
+a parent image, tv coordinates are identical to physical coordinates.
+In the tv coordinate system the coordinates of the first pixel of a 
+2D image, e.g. dev$ypix and a 2D image section, e.g. dev$ypix[200:300,200:300]
+are (1,1) and (200,200) respectively.
+.le
+.ls physical
+Physical coordinates are pixel coordinates invariant  with respect to linear
+transformations of the physical image data.  For example, if the current image
+was created by extracting a section of another image,  the  physical
+coordinates of an object in the current image will be equal to the physical
+coordinates of the same object in the parent image,  although the logical
+coordinates will be different.  In the physical coordinate system the
+coordinates of the first pixel of a 2D image, e.g. dev$ypix and a 2D
+image section, e.g. dev$ypix[200:300,200:300] are (1,1) and (200,200)
+respectively.
+.le
+.ls world
+World coordinates are image coordinates in any units which are invariant
+with respect to linear transformations of the physical image data. For
+example, the ra and dec of an object will always be the same no matter
+how the image is linearly transformed. The units of input world coordinates
+must be the same as those expected by the image header wcs, e. g. 
+degrees and degrees for celestial coordinate systems.
+.le
+The wcsin and wcsout parameters default to the values of the package
+parameters of the same name. The default values of the package parameters
+wcsin and wcsout are "logical" and "logical" respectively. 
+.le
+.ls cache = ")_.cache"
+Cache the image pixels in memory. Cache may be set to the value of the apphot
+package parameter (the default), "yes", or "no". By default cacheing is 
+disabled.
+.le
+.ls verify = ")_.verify"
+Verify the critical parameters in non-interactive mode ? Verify may be set to
+the apphot package parameter value (the default), "yes", or "no.
+.le
+.ls update = ")_.update"
+Update the critical parameters in non-interactive mode if \fIverify\fR is
+set to yes? Update may be set to the apphot package parameter value (the
+default), "yes", or "no.
+.le
+.ls verbose = ")_.verbose"
+Print messages on the terminal in non-interactive mode ? Verbose may be set
+to the apphot package parameter value (the default), "yes", or "no.
+.le
+.ls graphics = ")_.graphics"
+The default graphics device.
+Graphics may be set to the apphot package parameter value (the default), "yes",
+or "no.
+.le
+.ls display = ")_.display"
+The default display device.  Display may be set to the apphot package
+parameter value (the default), "yes", or "no. By default graphics overlay
+is disabled.  Setting display to one of "imdr", "imdg", "imdb", or "imdy"
+enables graphics overlay with the IMD graphics kernel.  Setting display to
+"stdgraph" enables CENTER to work interactively from a contour plot.
+.le
+
+.ih
+DESCRIPTION
+CENTER computes accurate centers for a set of objects in the IRAF image
+\fIimage\fR, whose initial coordinates are read from the image display cursor, 
+from the text file \fIcoords\fR, or from a cursor command file.
+The computed x and y coordinates, the errors,  and the fitting parameters
+are written to the text file \fIoutput\fR.
+
+The coordinates read from \fIcoords\fR are assumed to be in coordinate
+system defined by \fIwcsin\fR. The options are "logical", "tv", "physical",
+and "world" and the transformation from the input coordinate system to
+the internal "logical" system is defined by the image coordinate system.
+The simplest default is the "logical" pixel system. Users working on with
+image sections but importing pixel coordinate lists generated from the parent
+image must use the "tv" or "physical" input coordinate systems.
+Users importing coordinate lists in world coordinates, e.g. ra and dec,
+must use the "world" coordinate system and may need to convert their
+equatorial coordinate units from hours and degrees to degrees and degrees first.
+
+The coordinates written to \fIoutput\fR are in the coordinate
+system defined by \fIwcsout\fR. The options are "logical", "tv",
+and "physical". The simplest default is the "logical" system. Users
+wishing to correlate the output coordinates of objects measured in
+image sections or mosaic pieces with coordinates in the parent
+image must use the "tv" or "physical" coordinate systems.
+
+If \fIcache\fR is yes and the host machine physical memory and working set size
+are large enough, the input image pixels are cached in memory. If cacheing
+is enabled and CENTER is run interactively the first measurement will appear
+to take a long time as the entire image must be read in before the measurement
+is actually made. All subsequent measurements will be very fast because CENTER
+is accessing memory not disk. The point of cacheing is to speed up random
+image access by making the internal image i/o buffers the same size as the
+image itself. However if the input object lists are sorted in row order and
+sparse cacheing may actually worsen not improve the execution time. Also at
+present there is no point in enabling cacheing for images that are less than
+or equal to 524288 bytes, i.e. the size of the test image dev$ypix, as the
+default image i/o buffer is exactly that size. However if the size of dev$ypix
+is doubled by converting it to a real image with the chpixtype task then the
+effect of cacheing in interactive is can be quite noticeable if measurements
+of objects in the top and bottom halves of the image are alternated.
+
+CENTER can be run either interactively or in batch mode by setting the
+parameter \fIinteractive\fR. In interactive mode starting x and y positions
+can either be read directly from the image cursor or read from the text
+file \fIcoords\fR. In interactive mode the user can examine, adjust, and
+save the algorithm parameters, change ojects interactively, query for
+the next or nth object in the list, or fit the entire coordinate list with
+the chosen parameter set.  In batch mode the positions can be read from the
+text file \fIcoords\fR or the image cursor can be redirected to a text file
+containing a list of cursor commands as specified by the parameter
+\fIicommands\fR. 
+
+.ih
+CURSOR COMMANDS
+
+The following cursor commands are currently available.
+
+.nf
+	Interactive Keystroke Commands
+
+?	Print help
+:	Colon commands
+v	Verify the critical parameters
+w	Save the current parameters
+d	Plot radial profile of current star
+i	Interactively set parameters using current star
+f	Fit center of current star
+spbar	Fit center of current star, output results
+m	Move to next star in coordinate list
+n	Center next star in coordinate list, output results
+l	Center remaining stars in coordinate list, output results
+e	Print error messages
+r	Rewind the coordinate list
+q	Exit task
+
+
+	Colon Commands
+
+:show	[data/center]	List the parameters
+:m      [n]	        Move to next [nth] star in coordinate list
+:n      [n]	        Center next [nth] star in coordinate list,
+			output results
+
+
+	Colon Parameter Editing Commands
+
+# Image and file name parameters
+
+:image		[string]	Image name
+:coords		[string]	Coordinate file name
+:output 	[string]	Output file name
+
+# Data dependent parameters
+
+:scale		[value]		Image scale (units per pixel)
+:fwhmpsf	[value]		Full-width half-maximum of PSF (scale units)
+:emission	[y/n]		Emission feature (y), absorption (n)
+:sigma		[value]		Standard deviation of sky (counts)
+:datamin	[value]		Minimum good data value (counts)
+:datamax	[value]		Maximum good data value (counts)
+
+# Noise parameters
+
+:noise 		[string]	Noise model (constant|poisson)
+:gain		[string]	Gain image header keyword
+:ccdread	[string]	Readout noise image header keyword
+:epadu		[value]		Gain (electrons per adu)
+:readnoise	[value]		Readout noise (electrons)
+
+# Observations parameters
+
+:exposure	[string]	Exposure time image header keyword
+:airmass	[string]	Airmass image header keyword
+:filter		[string]	Filter image header keyword
+:obstime	[string]	Time of observation image header keyword
+:itime		[value]		Exposure time (time units)
+:xairmass	[value]		Airmass value (number)
+:ifilter	[string]	Filter id string
+:otime		[string]	Time of observation (time units)
+
+# Centering parameters 
+
+:calgorithm	[string]	Centering algorithm
+:cbox		[value]		Width of centering box (scale units)
+:cthreshold	[value]		Centering intensity threshold (sigma)
+:cmaxiter	[value]		Maximum number of iterations
+:maxshift	[value]		Maximum center shift (scale units)
+:minsnratio	[value]		Minimum signal to noise for centering
+:clean		[y/n]		Clean subraster before centering
+:rclean		[value]		Cleaning radius (scale units)
+:rclip		[value]		Clipping radius (scale units)
+:kclean		[value]		Clean K-sigma rejection limit (sigma)
+
+# Plotting and marking parameters
+
+:mkcenter	[y/n]		Mark computed centers on the display
+:radplot	[y/n]		Plot radial profile of object
+
+
+The following keystroke commands are available from the interactive setup
+menu.
+
+                    Interactive Center Setup Menu
+
+	v	Mark and verify the critical center parameters (f,s,c)
+
+	f	Mark and verify the full-width half-maximum of the psf
+	s	Mark and verify the standard deviation of the background
+	l	Mark and verify the minimum good data value
+	u	Mark and verify the maximum good data value
+
+	c	Mark and verify the centering box half-width
+	n	Mark and verify the cleaning radius
+	p	Mark and verify the clipping radius
+.fi
+
+.ih
+ALGORITHMS
+
+Descriptions of the data dependent parameters and the centering
+algorithm parameters can be found in the online manual pages for
+\fIdatapars\fR and \fIcenterpars\fR.
+
+.ih
+OUTPUT
+
+In interactive mode the following quantities are written to the terminal
+as each object is measured. Error is a simple string which indicates
+whether an error condition has been flagged.  The centers and their errors are
+in pixel units.
+
+.nf
+	image  xinit  yinit  xcenter  ycenter  xerr  yerr  error
+.fi
+
+In both interactive and batch mode the full output is written to the
+text file \fIoutput\fR. At the beginning of each file is a header
+listing the current values of the parameters when the first stellar
+record was written. These parameters can be subsequently altered.
+For each star measured the following record is written
+
+.nf
+	image  xinit  yinit  id  coords  lid
+	   xcenter  ycenter  xshift  yshift  xerr  yerr  cier error
+.fi
+
+Image and coords are the name of the image and coordinate file respectively.
+Id and lid are the sequence numbers of stars in the output and coordinate
+files respectively. Cier and error are the centering error code and accompanying
+error message respectively.  Xinit, yinit, xcenter, ycenter, xshift, yshift,
+and xerr, yerr are self explanatory and output in pixel units. The sense of
+the xshift and yshift definitions is the following.
+
+.nf
+	xshift = xcenter - xinit
+	yshift = ycenter - yinit
+.fi
+
+In interactive mode a radial profile of each measured object is plotted
+in the graphics window if \fIradplots\fR is "yes".
+
+In interactive and batchmode a radial profile plot is written to
+\fIplotfile\fR  if it is defined each time the result of an object
+measurement is written to \fIoutput\fR .
+
+.ih
+ERRORS
+
+If the object centering was error free then the field cier will be zero.
+Non-zero values in the cier column flag the following error conditions.
+
+.nf
+	0        # No error
+	101      # The centering box is off the image
+	102      # The centering box is partially off the image
+	103      # The S/N ratio is low in the centering box
+	104      # There are two few points for a good fit
+	105      # The x or y center fit is singular
+	106      # The x or y center fit did not converge
+	107      # The x or y center shift is greater than maxshift
+	108      # There is bad data in the centering box
+.fi
+
+.ih
+EXAMPLES
+
+1. Compute the centers for a few  stars in dev$ypix using the image display
+and the image cursor. Setup the task parameters using the interactive
+setup menu defined by the i keystroke command and a radial profile plot.
+
+.nf
+	ap> display dev$ypix 1 fi+
+
+	... display the image
+
+	ap> center dev$ypix
+
+	... type ? to see help screen
+
+	... move image cursor to a star
+	... type i to enter the interactive setup menu
+	... enter the maximum radius in pixels for the radial profile or
+	    accept the default with a CR
+	... type  v to get the default menu
+	... set the fwhmpsf, sigma, and centering box half-width using the
+	    graphics cursor and the stellar radial profile plot
+	... typing <CR> after a prompt leaves the parameter at its default
+	    value
+	... type q to exit setup menu
+
+	... type the v key to verify the critical parameters
+
+	... type the w key to save the parameters in the parameter files
+
+	... move the image cursor to the stars of interest and tap
+	    the space bar
+
+	... type q to quit followed by q to confirm the quit
+
+	... the output will appear in ypix.ctr.1
+
+.fi
+
+2. Compute the centers for a few stars in dev$ypix using the contour plot
+and the graphics cursor. This option is only useful for those (now very few)
+users who have access to a graphics terminal but not to an image display
+server. Setup the task parameters using the interactive setup menu defined by
+the i key command as in example 1.
+
+.nf
+	ap> show stdimcur
+
+	... record the default value of stdimcur
+
+	ap> set stdimcur = stdgraph
+
+	... define the image cursor to be the graphics cursor
+
+	ap> contour dev$ypix
+
+	... make a contour plot of dev$ypix
+
+	ap> contour dev$ypix >G ypix.plot1
+
+	... store the contour plot of ypix in the file ypix.plot
+
+	ap> center dev$ypix display=stdgraph
+
+	... type ? to see the help screen
+
+	... move graphics cursor to a star
+	... type i to enter the interactive setup menu
+	... enter the maximum radius in pixels for the radial profile or
+	    accept the default with a CR
+	... type v key to get the default setup menu
+	... enter maximum radius in pixels of the radial profile
+	... set the fwhmpsf, sigma, and centering box half-width
+	    using the graphics cursor and the stellar radial profile plot
+	... typing <CR> after the prompt leaves the parameter at its
+	    default value
+	... type q to quit the setup menu
+
+	... type the v key to verify critical parameters
+
+	... type the w key to save the parameters in the parameter files
+
+	... retype :.read ypix.plot1 to reload the contour plot
+
+	... move the graphics cursor to the stars of interest and tap
+	    the space bar
+
+	... a one line summary of the answers will appear on the standard
+	    output for each star measured
+
+	... type q to quit followed by q to confirm the quit
+
+	... full output will appear in the text file ypix.ctr.2 
+
+	ap> set stdimcur = <default>
+
+	... reset stdimcur to its previous value
+.fi
+
+
+3. Setup and run CENTER interactively on a list of objects temporarily
+overriding the fwhmpsf, sigma, and cbox parameters determined in examples
+1 or 2.
+
+.nf
+	ap> daofind dev$ypix fwhmpsf=2.6 sigma=25.0 verify-
+
+	... make a coordinate list 
+
+	... the output will appear in the text file ypix.coo.1
+
+	ap> center dev$ypix cbox=7.0 coords=ypix.coo.1 
+
+	... type ? for optional help
+
+
+	... move the graphics cursor to the stars and tap space bar
+
+				or
+
+	... select stars from the input coordinate list with m / :m #
+	    and measure with spbar
+
+	... measure stars selected from the input coordinate list
+	    with n / n #
+
+	... a one line summary of results will appear on the standard output
+	    for each star measured
+
+	... the output will appear in ypix.ctr.3 ...
+.fi
+
+
+4. Display and measure some stars in an image section and write the output
+coordinates in the coordinate system of the parent image.
+
+.nf
+	ap> display dev$ypix[150:450,150:450] 1
+
+	... display the image section
+
+	ap> center dev$ypix[150:450,150:450] wcsout=tv
+
+	... move cursor to stars and type spbar
+
+	... type q to quit and q again to confirm quit
+
+	... output will appear in ypix.ctr.4
+
+	ap> pdump ypix.ctr.4 xc,yc yes | tvmark 1 STDIN col=204 
+.fi
+
+
+5. Run CENTER in batch mode using the coordinate file and the previously
+saved parameters. Verify the critical parameters.
+
+.nf
+	ap> center dev$ypix coords=ypix.coo.1 verify+ inter-
+
+	... output will appear in ypix.ctr.5 ...
+.fi
+
+
+6. Repeat example 5 but assume that the input coordinate are ra and dec
+in degrees and degrees, turn off verification, and submit the task to to
+the background.
+
+.nf
+	ap> display dev$ypix
+
+	ap> rimcursor wcs=world > radec.coo
+
+	... move to selected stars and type any key
+
+	... type ^Z to quit
+
+	ap> center dev$ypix coords=radec.coo wcsin=world verify- inter- &
+
+	... output will appear in ypix.ctr.6
+
+	ap> pdump ypix.ctr.6 xc,yc yes | tvmark 1 STDIN col=204
+
+	... mark the stars on the display
+
+
+7. Run CENTER interactively without using the image display.
+
+.nf
+	ap> show stdimcur
+
+	... record the default value of stdimcur
+
+	ap> set stdimcur = text
+
+	... set the image cursor to the standard input
+
+	ap> center dev$ypix coords=ypix.coo.1
+
+	... type ? for optional help
+
+	... type :m 3 to set the initial coordinates to those of the
+	    third star in the list
+
+	... type i to enter the interactive setup menu
+	... enter the maximum radius in pixels for the radial profile or
+	    accept the default with a CR
+	... type v to enter the default menu
+	... set the fwhmpsf, sigma, and centering box half-width
+	    using the graphics cursor and the stellar radial profile plot
+	... typing <CR> after the prompt leaves the parameter at its default
+	    value
+
+	... type r to rewind the coordinate list
+
+	... type l to measure all the stars in the coordinate list
+
+	... a one line summary of the answers will appear on the standard
+	    output for each star measured
+
+	... type q to quit followed by q to confirm the quit
+
+	... full output will appear in the text file ypix.ctr.7 
+
+	ap> set stdimcur = <default>
+
+	... reset the value of stdimcur
+.fi
+
+8. Use a image cursor command file to drive the CENTER task. The cursor command
+file shown below sets the fwhmpsf, calgorithm, and cbox parameters, computes
+the centers for 3 stars, updates the parameter files, and quits the task.
+
+.nf
+	ap> type cmdfile
+	: calgorithm gauss
+	: fwhmpsf 2.5
+	: cbox 9.0
+	442 410 101 \040 
+	349 188 101 \040 
+	225 131 101 \040 
+	w
+	q
+
+	ap> center dev$ypix icommands=cmdfile  verify-
+
+	... full output will appear in ypix.ctr.8
+.fi
+
+.ih
+BUGS
+
+It is the responsibility of the user to make sure that the image displayed
+in the image display is the same as the image specified by the image parameter.
+
+Commands which draw to the image display are disabled by default.
+To enable graphics overlay on the image display, set the display
+parameter to "imdr", "imdg", "imdb", or "imdy" to get red, green,
+blue or yellow overlays and set the centerpars mkcenter switch to
+"yes". It may be necessary to run gflush and to redisplay the image
+to get the overlays position correctly. 
+
+.ih
+SEE ALSO
+datapars, centerpars
+.endhelp
diff --git a/noao/digiphot/apphot/doc/centerpars.hlp b/noao/digiphot/apphot/doc/centerpars.hlp
new file mode 100644
index 00000000..008869f4
--- /dev/null
+++ b/noao/digiphot/apphot/doc/centerpars.hlp
@@ -0,0 +1,206 @@
+.help centerpars May00 noao.digiphot.apphot
+.ih
+NAME
+centerpars -- edit the centering algorithm parameters
+.ih
+USAGE
+centerpars
+.ih
+PARAMETERS
+.ls calgorithm = "centroid"
+The centering algorithm. The "gauss" and "ofilter" options depend critically
+on the value of the fwhmpsf parameter in the DATAPARS task. The centering
+options are:
+.ls none
+The initial positions are assumed to be the true centers. Users
+may select this option if the initial centers are know to be accurate,
+e.g. they were computed by DAOFIND task.
+.le
+.ls centroid
+The object centers are determined by computing the intensity weighted means
+of the marginal profiles in x and y.  This is the recommended default algorithm
+for APPHOT users.
+.le
+.ls gauss
+The object centers are computed by fitting a Gaussian of fixed fwhmpsf,
+specified by the DATAPARS fwhmpsf parameter, to the marginal profiles in
+x and y using non-linear least squares techniques.
+.le
+.ls ofilter
+The object centers are computed using optimal filtering techniques,
+a triangular weighting function of half width equal to fwhmpsf as
+specified by the DATAPARS fwhmpsf parameter, and the marginal distributions
+in x and y.
+.le
+.le
+.ls cbox = 5.0  (scale units)
+The width of the subraster used for object centering in units of the
+DATAPARS scale parameter. Cbox must be big enough to include a reasonable
+number of pixels  for center determination but not so large so as to include
+a lot of noise. Recommended initial values are 2.5-4.0 * the FWHM of the PSF
+value.
+.le
+.ls cthreshold = 0.0 (sigma units)
+Pixels cthreshold * sigma above (emission features) or below (absorption
+features) the data minimum or maximum respectively are used by the centering
+algorithms where sigma is equal to the value of the DATAPARS sigma parameter. 
+Most APPHOT users should leave this value at 0.0 which invokes the appropriate
+default thresholding technique for each centering algorithm. Setting cthreshold
+to INDEF turns off thresholding altogether for all the centering algorithms.
+.le
+.ls minsnratio = 1.0
+The minimum signal to noise ratio for object centering. If the estimated signal
+to noise ratio is less than minsnratio the computed center will be returned
+with an error flag.
+.le
+.ls cmaxiter = 10
+The maximum number of iterations performed by the centering algorithm.
+All the centering algorithms use this parameter.
+.le
+.ls maxshift = 1.0  (scale units)
+The maximum permissible shift of the center with respect to the initial
+coordinates in units of the scale parameter. If the shift produced by the
+centering algorithms is larger than maxshift, the computed center is returned
+with an error flag.
+.le
+.ls clean = no
+Symmetry-clean the centering subrater before centering? APPHOT users should
+leave clean set to "no".
+.le
+.ls rclean = 1.0  (scale units)
+The cleaning radius for the symmetry-clean algorithm in units of the scale
+parameter.
+.le
+.ls rclip = 2.0  (scale units)
+The clipping radius for the symmetry-clean algorithm in units of the scale
+parameter.
+.le
+.ls kclean = 3.0  (sigma)
+The number of sky background standard deviations for the symmetry-clean
+algorithm where sigma is the value of the DATAPARS parameter sigma.
+.le
+.ls mkcenter = no
+Mark the fitted object centers on the displayed image ?
+.le
+.ih
+DESCRIPTION
+
+The centering algorithm parameters control the action of the centering
+algorithms. The default parameters values have been proven to produce
+reasonable results in the majority of cases. Several of the centering
+parameters are defined in terms of the DATAPARS parameter \fIscale\fR,
+the scale of the image, and \fIsigma\fR the standard deviation of
+the sky pixels. 
+
+For each object to be measured a subraster of data \fIcbox\fR / \fIscale\fR
+pixels wide around the initial position supplied by the user is extracted
+from the IRAF image. If scale is defined in units of the number
+the half-width half-maximum of the psf per pixel, then a single value of
+cbox can be used for centering objects in images with different psfs.
+
+If \fIclean\fR is "yes" the symmetry-clean algorithm is applied to the
+centering subraster prior to centering. The cleaning algorithm attempts
+to correct defects in the centering subraster by assuming that the image
+is radially symmetric and comparing pixels on opposite sides of the center
+of symmetry.  The center of symmetry is assumed to be the maximum pixel
+in the subraster, unless the maximum pixel is more than \fImaxshift /
+scale\fR from the initial center, in which case the initial center is used
+as the center of symmetry.  Pixels inside the cleaning radius are not edited.
+Pairs of pixels in the cleaning region, r > \fIrclean\fR / \fIscale\fR
+and r <= \fIrclip\fR / \fIscale\fR and diametrically opposed about the
+center of symmetry are tested for equality. If the difference between the
+pixels is greater than \fIkclean * sigma\fR, the larger value is replaced
+by the smaller.  In the cleaning region the sigma is determined by the
+noise model assumed for the data. Pairs of pixels in the clipping region,
+r > \fIrclip\fR / \fIscale\fR are tested in the same manner as those in
+the cleaning region. However the sigma employed is the sigma of the
+sky background. Most APPHOT users should leave clean set to "no".
+
+New centers are computed using the centering algorithm specified by
+\fIcalgorithm\fR, the data specified by \fIcbox / scale\fR, and pixels
+that are some threshold above (below) an estimate of the local minimum
+(maximum). \fICthreshold\fR values of 0.0, a positive number, and INDEF
+invoke the default thresholding algorithm, a threshold equal to the
+local minimum (maximum) plus  (minus) \fIdatapars.sigma * cthreshold\fR,
+and a threshold exactly equal to the local minimum (maximum) respectively.
+
+After thresholding the signal to noise ratio of the subraster is estimated. 
+If the SNR < \fIminsnratio\fR the new center is still computed but an error
+flag is set.
+
+The default centering algorithm is \fIcentroid\fR. Centroid computes the
+intensity weighted mean and mean error of the centering box x and y marginal
+distributions using points in the marginal arrays above (below) the minimum
+(maximum) data pixel plus (minus) a threshold value.
+
+The threshold value is either the mean, \fIdatapars.sigma * cthreshold\fR
+above (below) the local minimum (maximum) if \fIcthreshold\fR is greater
+than zero, or zero above (below) the local minimum (maximum) if
+\fIcthreshold\fR is INDEF.  The centroid algorithm is similar to that
+by the old KPNO Mountain Photometry Code. Note that centroid is the only
+centering algorithm which does not depend on the value of
+\fIdatapars.fwhmpsf\fR.
+
+The centering algorithm \fIgauss\fR computes the new centers by fitting a
+1D Gaussian function to the marginal distributions in x and y using a
+fixed fwhmpsf set by \fIdatapars.fwhmpsf\fR.  Initial guesses for the fit
+parameters are derived from the data. The gauss algorithm iterates until
+a best fit solution is achieved.
+
+The final centering algorithm choice \fIofilter\fR employs a variation of the
+optimal filtering technique in which the profile is simulated by a triangle
+function of width \fIdatapars.fwhmpsf\fR.
+
+The default thresholding algorithm for all centering algorithms other
+than "centroid" is no thresholding.
+
+If the computed shift in either coordinate > \fImaxshift\fR / \fIscale\fR,
+the new center is returned but an error flag is set.
+
+.ih
+EXAMPLES
+1. List the centering parameters.
+
+.nf
+	ap> lpar centerpars
+.fi
+
+2. Edit the centering parameters
+
+.nf
+	ap> centerpars
+.fi
+
+3. Edit the CENTERPARS parameters from with the PHOT task.
+
+.nf
+    da> epar phot
+
+	... edit a few phot parameters
+
+	... move to the centerpars parameter and type :e
+
+	... edit the centerpars parameters and type :wq
+
+	... finish editing the phot parameters and type :wq
+.fi
+
+4. Save the current CENTERPARS parameter set in a text file ctrnite1.par.
+This can also be done from inside a higher level task as in the
+previous example.
+
+.nf
+    da> centerpars
+
+	... edit the parameters
+
+	... type ":w ctrnite1.par"  from within epar
+.fi
+
+.ih
+BUGS
+
+.ih
+SEE ALSO
+center,phot,wphot,polyphot,radprof
+.endhelp
diff --git a/noao/digiphot/apphot/doc/daofind.hlp b/noao/digiphot/apphot/doc/daofind.hlp
new file mode 100644
index 00000000..ad9687e5
--- /dev/null
+++ b/noao/digiphot/apphot/doc/daofind.hlp
@@ -0,0 +1,579 @@
+.help daofind May00 noao.digiphot.apphot
+.ih
+NAME
+daofind -- automatically detect objects in an image
+.ih
+USAGE
+daofind image 
+.ih
+PARAMETERS
+.ls image
+The list of images in which objects are to be detected.
+.le
+.ls output  = "default"
+The name of the results file or the results directory. If output is
+"default", "dir$default" or a directory specification then a results file
+name of the form dir$root.extension.version is constructed, where
+dir is the directory, root is the root image name, extension is "coo"
+and version is the next available version number for the file. If the
+output string is undefined then no output file is created. One output
+file is created for every input image.
+.le
+.ls starmap = ""
+The name of the image prefix and/or directory where the density enhancement
+image will be stored. If starmap is undefined or a directory,
+DAOFIND will create a temporary image which is deleted on exit from
+the program. Otherwise starmap is prefixed to the image name
+and the density enhancement image will be saved for use in a subsequent
+run of DAOFIND.
+.le
+.ls skymap = ""
+The name of the image prefix and/or directory where the mean density
+image will be stored.  If skymap is undefined or a directory, no mean density
+image is created. Otherwise skymap is prefixed to the image name
+and the mean density image will be saved on disk. Skymap is not used by
+the DAOFIND algorithms, but may be used by the user as a check on DAOFIND,
+since the sum of starmap and skymap is a type of best fit to the original 
+image.
+.le
+.ls datapars = ""
+The name of the file containing the data dependent parameters. The critical
+parameters \fIfwhmpsf\fR and \fIsigma\fR are located here.  If \fIdatapars\fR
+is undefined then the default parameter set in the user's uparm directory is
+used.
+.le
+.ls findpars = ""
+The name of the file containing the object detection parameters. The 
+parameter \fIthreshold\fR is located here. If findpars is undefined then
+the default parameter set in the user's uparm directory is used.
+.le
+.ls boundary = "nearest"
+The type of boundary extension. The choices are:
+.ls nearest
+Use the value of the nearest boundary pixel.
+.le
+.ls constant
+Use a constant value.
+.le
+.ls reflect
+Generate a value by reflecting around the boundary.
+.le
+.ls wrap
+Generate a value by wrapping around to the other side of the image.
+.le
+.le
+.ls constant = 0
+The constant for constant boundary extension.
+.le
+.ls interactive = no
+Interactive or batch mode?
+.le
+.ls icommands = ""
+The image display cursor or image cursor command file.
+.le
+.ls gcommands = ""
+The graphics cursor or graphics cursor command file.
+.le
+.ls wcsout = ")_.wcsout"
+The coordinate system of the output coordinates written to \fIoutput\fR. The
+image header coordinate system is used to transform from the internal "logical"
+pixel coordinate system to the output coordinate system. The output coordinate
+system options are "logical", "tv", and "physical". The image cursor coordinate
+ system is assumed to be the "tv" system.
+.ls logical
+Logical coordinates are pixel coordinates relative to the current image.
+The  logical coordinate system is the coordinate system used by the image
+input/output routines to access the image data on disk. In the logical
+coordinate system the coordinates of the first pixel of a  2D image, e.g.
+dev$ypix  and a 2D image section, e.g. dev$ypix[200:300,200:300] are
+always (1,1).
+.le
+.ls tv  
+Tv coordinates are the pixel coordinates used by the display servers. Tv
+coordinates  include  the effects of any input image section, but do not
+include the effects of previous linear transformations. If the input
+image name does not include an image section, then tv coordinates are
+identical to logical coordinates.  If the input image name does include a
+section, and the input image has not been linearly transformed or copied from
+a parent image, tv coordinates are identical to physical coordinates.
+In the tv coordinate system the coordinates of the first pixel of a
+2D image, e.g. dev$ypix and a 2D image section, e.g. dev$ypix[200:300,200:300]
+are (1,1) and (200,200) respectively.
+.le
+.ls physical
+Physical coordinates are pixel coordinates invariant  with respect to linear
+transformations of the physical image data.  For example, if the current image
+was created by extracting a section of another image,  the  physical
+coordinates of an object in the current image will be equal to the physical
+coordinates of the same object in the parent image,  although the logical
+coordinates will be different.  In the physical coordinate system the
+coordinates of the first pixel of a 2D image, e.g. dev$ypix and a 2D
+image section, e.g. dev$ypix[200:300,200:300] are (1,1) and (200,200)
+respectively.
+.le
+The wcsout parameter defaults to the value of the package parameter of the same
+ name. The default values of the package parameters wcsin and wcsout are
+"logical" and "logical" respectively.
+.le
+.ls cache = ")_.cache"
+Cache the image pixels in memory. Cache may be set to the value of the apphot
+package parameter (the default), "yes", or "no". By default cacheing is 
+disabled.
+.le
+.ls verify = ")_.verify"
+Automatically confirm the critical parameters when running in non-interactive
+mode? Verify may be set to the apphot package parameter value (the default),
+"yes", or "no".
+.le
+.ls update = ")_.update"
+Automatically update the algorithm parameters in non-interactive mode if
+verify is "yes".  Update may be set to the apphot package parameter value
+(the default), "yes", or "no".
+.le
+.ls verbose = ")_.verbose"
+Print out information about the progress of the task in non-interactive mode.
+Verbose may be set to the apphot package parameter value (the default), "yes",
+or "no".
+.le
+.ls graphics = ")_.graphics"
+The standard graphics device. Graphics may be set to the apphot package
+parameter value (the default), "yes", or "no".
+.le
+.ls display = ")_.display"
+The standard image display device.  Display may be set to the apphot package
+parameter value (the default), "yes", or "no". By default graphics overlay is
+disabled.  Setting display to one of "imdr", "imdg", "imdb", or "imdy" enables
+graphics overlay with the IMD graphics kernel.  Setting display to "stdgraph"
+enables DAOFIND to work interactively from a contour plot.
+
+.le
+
+.ih
+DESCRIPTION
+
+DAOFIND searches the IRAF images \fIimage\fR for local density maxima,
+which have a full-width half-maximum of \fIdatapars.fwhmpsf\fR and a peak
+amplitude greater than \fIfindpars.threshold\fR * \fIdatapars.sigma\fR above
+the local background, and writes a list of detected objects in the file
+\fIoutput\fR.  The detected objects are also listed on the standard output
+if the program is running in interactive mode, or in non-interactive mode
+with the \fIverbose\fR switch is turned on.
+
+The coordinates written to \fIoutput\fR are in the coordinate
+system defined by \fIwcsout\fR. The options are "logical", "tv",
+and "physical". The simplest default is the "logical" system. Users
+wishing to correlate the output coordinates of objects measured in
+image sections or mosaic pieces with coordinates in the parent
+image must use the "tv" or "physical" coordinate systems.
+
+If \fIcache\fR is yes and the host machine physical memory and working set size
+are large enough, the input and output image pixels are cached in memory. If
+cacheing is enabled and DAOFIND is run interactively the first measurement
+will appear to take a long time as the entire image must be read in before the
+measurement is actually made. All subsequent measurements will be very fast
+because DAOFIND is accessing memory not disk. The point of cacheing is to speed
+up random image access by making the internal image i/o buffers the same size
+as the image itself. However if the input object lists are sorted in row order
+and sparse cacheing may actually worsen not improve the execution time. Also at
+present there is no point in enabling cacheing for images that are less than
+or equal to 524288 bytes, i.e. the size of the test image dev$ypix, as the
+default image i/o buffer is exactly that size. However if the size of dev$ypix
+is doubled by converting it to a real image with the chpixtype task then the
+effect of cacheing in interactive is can be quite noticeable if measurements
+of objects in the top and bottom halfs of the image are alternated.
+
+DAOFIND can be run either interactively or in batch mode by setting the
+parameter \fIinteractive\fR. In interactive mode the user can examine,
+adjust, and save algorithm parameters, and fit or refit the  entire coordinate
+list with the chosen parameter set.  The \fIverify\fR parameter can be used
+to automatically enable confirmation of the critical parameters
+\fIdatapars.fwhmpsf\fR and \fIdatapars.sigma\fR when running in
+non-interactive mode.
+
+
+.ih
+CURSOR COMMANDS
+
+.nf
+
+	     Interactive Keystroke Commands
+
+?	Print help
+:	Colon commands 
+v	Verify the critical parameters
+w	Save the current parameters
+d	Plot radial profile of star near cursor
+i	Interactively set parameters using star near cursor
+f	Find stars in the image
+spbar	Find stars in the image, output results
+q	Exit task
+
+
+		Colon Commands
+
+:show		[data/find]	List the parameters
+
+		Colon Parameter Editing Commands
+
+# Image and file name parameters
+
+:image		[string]	Image name
+:output		[string]	Output file name
+
+# Data dependent parameters
+
+:scale		[value]		Image scale (units per pixel)
+:fwhmpsf	[value]		Full width half maximum of psf (scale units)
+:emission	[y/n]		Emission feature (y), absorption (n)
+:sigma		[value]		Standard deviation of sky (counts)
+:datamin	[value]		Minimum good data value (counts)
+:datamax	[value]		Maximum good data value (counts)
+
+# Noise description parameters
+
+:noise 		[string]	Noise model (constant|poisson)
+:gain		[string]	Gain image header keyword
+:ccdread	[string]	Readout noise image header keyword
+:epadu		[value]		Gain (electrons per adu)
+:readnoise	[value]		Readout noise (electrons)
+
+# Observation parameters
+
+:exposure	[string]	Exposure time image header keyword
+:airmass	[string]	Airmass image header keyword
+:filter		[string]	Filter image header keyword
+:obstime	[string]	Time of observation image header keyword
+:itime		[value]		Exposure time (time units)
+:xairmass	[value]		Airmass value (number)
+:ifilter	[string]	Filter id string
+:otime		[string]	Time of observation (time units)
+
+# Object detection parameters
+
+:nsigma		[value]		Size of Gaussian kernel (sigma) 
+:threshold	[value]		Detection intensity threshold (counts)
+:ratio		[value]		Sigmay / sigmax of Gaussian kernel
+:theta		[value]		Position angle of Gaussian kernel
+:sharplo	[value]		Lower bound on sharpness
+:sharphi	[value]		Upper bound on sharpness
+:roundlo	[value]		Lower bound on roundness
+:roundhi	[value]		Upper bound on roundness
+
+# Plotting and marking commands
+
+:mkdetections	[y/n]		Mark detections on the image display
+
+
+The following commands are available inside the interactive setup menu.
+
+ 
+                    Interactive Daofind Setup Menu
+
+	v	Mark and verify critical daofind parameters (f,s)
+
+	f	Mark and verify the full-width half-maximum of the psf
+	s	Mark and verify the standard deviation of the background
+	l	Mark and verify the minimum good data value
+	u	Mark and verify the maximum good data value
+.fi
+
+.ih
+ALGORITHMS
+
+DAOFIND approximates the stellar point spread function with an elliptical
+Gaussian function, whose sigma along the semi-major axis is 0.42466 *
+\fIdatapars.fwhmpsf\fR / \fIdatapars.scale\fR pixels, semi-minor to semi-major
+axis ratio is \fIratio\fR, and major axis position angle is \fItheta\fR.
+Using this model, a convolution kernel, truncated at \fInsigma\fR sigma,
+and normalized so as to sum to zero, is constructed.
+
+The density enhancement image \fIstarmap\fR is computed by convolving the input
+image with the Gaussian kernel. This operation is mathematically equivalent to
+fitting, in the least-squares sense, the image data at each point with a
+truncated, lowered elliptical Gaussian function. After convolution each point
+in \fIstarmap\fR contains as estimate of the amplitude of the best fitting
+Gaussian function at that point. Each point in \fIskymap\fR, if the user
+chooses to compute it, contains an estimate of the best fitting sky value
+at that point.
+
+After image convolution , DAOFIND steps through \fIstarmap\fR searching
+for density enhancements greater than \fIfindpars.threshold\fR *
+\fIdatapars.sigma\fR, and brighter than all other density enhancements within
+a semi-major axis of 0.42466 \fIfindpars.nsigma\fR * \fIdatapars.fwhmpsf\fR.
+As the program selects candidates, it computes three shape characteristics,
+sharpness and 2 estimates of roundness.  The sharpness statistic measures the
+ratio of, the difference between the height of the central pixel and the mean
+of the surrounding non-bad pixels, to the height of the best fitting Gaussian
+function at that point. The first roundness characteristic computes the ratio
+of a measure of the bilateral symmetry of the object to a measure of the
+four-fold symmetry of the object. The second roundness statistic measures the
+ratio of, the difference in the height of the best fitting Gaussian function
+in x minus the best fitting Gaussian function in y, over the average of the
+best fitting Gaussian functions in x and y. The limits on these parameters
+\fIfindpars.sharplo\fR, \fIfindpars.sharphi\fR \fIfindpars.roundlo\fR, and
+\fIfindpars.roundhi\fR, are set to weed out non-astronomical objects and
+brightness enhancements that are elongated in x and y respectively.
+
+Lastly the x and y centroids of the detected objects are computed by estimating
+the x and y positions of the best fitting 1D Gaussian functions in x and y
+respectively, a rough magnitude is estimated by computing the ratio of the
+amplitude of the best fitting Gaussian at the object position to
+\fIfindpars.threshold\fR * \fIdatapars.sigma\fR, and the object is added to
+the output coordinate file.
+
+.ih
+OUTPUT
+
+In interactive mode or in non-interactive with the verbose switch turned on
+the following quantities are written to the terminal as each object is
+detected.
+
+.nf
+	xcenter  ycenter  mag  sharpness  sround  ground id
+
+		    where
+
+	mag = -2.5 * log10 (peak density / detection threshold)
+.fi
+
+The object centers are in pixels and the magnitude estimate measures the
+ratio of the maximum density enhancement to the detection threshold. 
+Sharpness is typically around .5 to .8 for a star with a fwhmpsf similar to
+the pattern star. Both sround and ground are close to zero for a truly 
+round star. Id is the sequence number of the star in the list.
+
+In both interactive and batch mode the full output is written to the text
+file \fIoutput\fR. At the beginning of each file is a header, listing
+the current values of the parameters when the first stellar record was
+written. The parameters can subsequently be altered. 
+
+.ih
+EXAMPLES
+
+1. Run daofind interactively on dev$ypix using the image display
+and image display cursor. Set the fwhmpsf and sigma parameters
+with the graphics cursor,  radial profile plot, and the interactive
+setup key i.
+
+.nf
+	ap> display dev$ypix 1 fi+
+
+	... display the image
+
+	ap> daofind dev$ypix interactive+
+
+	... type ? to see help screen
+
+	... move display cursor to a star
+	... type i to enter the interactive setup menu
+	... enter maximum radius in pixels of the radial profile or
+            accept default with a CR
+	... set the fwhmpsf and sigma using the graphics cursor and the
+	    radial profile plot
+	... typing <CR> leaves the parameters at their default values
+        ... type q to quit setup menu
+
+	... type the v key to verify the critical parameters
+
+	... type the w key to save the parameters in the parameter files
+
+	... type the space bar to detect stars in the image
+
+	... a 1 line summary of the answers will appear on the standard
+	    output for each star measured
+
+	... type q to quit and q again to confirm the quit
+
+	... full output will appear in the text file ypix.coo.1
+
+.fi
+
+2. Run daofind interactively on a single image using a contour plot in place
+of the image and the graphics cursor in place of the image cursor.
+This option is only useful for those (now very few) users who have access to
+a graphics terminal but not to an image display server. Set the fwhmpsf and
+sigma parameters with the graphics cursor and radial profile plot and the
+interactive setup key i.
+
+.nf
+        ap> show stdimcur
+
+        ... record the default value of stdimcur
+
+	ap> set stdimcur = stdgraph
+
+	... define the image cursor to be the graphics cursor
+
+        ap> contour dev$ypix
+
+        ... make a contour plot of dev$ypix
+
+	ap> contour dev$ypix >G ypix.plot1
+
+        ... store the contour plot of ypix in the file ypix.plot
+
+	ap> daofind dev$ypix display=stdgraph interactive+
+
+        ... type ? to see the help screen
+
+	... move graphics cursor to a setup star
+	... type i to enter the interactive setup menu
+	... enter maximum radius in pixels of the radial profile or
+            accept the default with a CR
+	... set the fwhmpsf and sigma using the graphics cursor and the
+	    radial profile plot
+	... typing <CR> leaves the parameters at their default values
+        ... type q to quit the setup menu
+
+	... type the v key to confirm the critical parameters
+
+	... type the w key to save the parameters in the parameter files
+
+        ... retype :.read ypix.plot1 to reload the contour plot
+
+	... type the space bar to detect stars in the image
+
+	... a 1 line summary of the answers will appear on the standard
+	    output for each star measured
+
+	... full output will appear in the text file ypix.coo.2
+
+	ap> set stdimcur = <default>
+
+        ... reset the image cursor to its default value
+
+.fi
+
+
+3. Run DAOFIND interactively without using the image display cursor.
+
+.nf
+        ap> show stdimcur
+
+        ... record the default value of stdimcur
+
+	ap> set stdimcur = text
+
+	... set the image cursor to the standard input
+
+	ap> display dev$ypix 1
+
+	... display the image
+
+	ap> daofind dev$ypix interactive+
+
+        ... type ? for help
+
+	... type "442 409 101 i" in response to the image cursor query where
+	    x and y are the coordinates of the star to be used as setup,
+	    101 is the default world coordinate system, and i enters the
+	    interactive setup menu.
+	... enter maximum radius in pixels of the radial profile or
+            type CR to accept the default
+	... set the fwhmpsf and sigma using the graphics cursor and the
+	    radial profile plot
+	... typing <CR> leaves the parameters at their default values
+        ... type q to quit the setup menu
+
+	... type the v key to verify the parameters
+
+	... type the w key to save the parameters in the parameter files
+
+	... type the space bar to detect stars in the image
+
+	... a 1 line summary of the answers will appear on the standard
+	    output for each star measured
+
+	... type q to quit and q again to confirm
+
+	... full output will appear in the text file ypix.coo.3
+
+	ap> set stdimcur = <default>
+
+        ... reset the image cursor to its default value
+.fi
+
+
+4. Run daofind on a list of 3 images contained in the file imlist in batch mode.
+The program will ask the user to verify that the fwhmpsf and the threshold are
+correct before beginning execution.
+
+.nf
+	ap> type imlist
+	dev$ypix
+	dev$wpix
+	dev$pix
+
+	ap> daofind @imlist
+
+        ... the output will appear in ypix.coo.4, wpix.coo.1, pix.coo.1
+.fi
+
+
+5. Display and find stars in an image section. Write the output coordinates
+in the coordinate system of the parent image. Mark the detected stars on
+the displayed image.
+
+.nf
+        ap> display dev$ypix[150:450,150:450]
+
+        ... display the image section
+
+        ap> daofind dev$ypix[150:450,150:450] wcsout=tv
+
+        ... output will appear in ypix.coo.5
+
+        ap> tvmark 1 ypix.coo.5 col=204
+.fi
+
+
+6. Repeat example 4 but submit the job to the background  and turn off the
+verify switch.
+
+.nf
+	ap> daofind @imlist verify- &
+
+	... the output will appear in ypix.coo.6, wpix.coo.2, pix.coo.2
+.fi
+
+
+7. Use an image cursor command file to drive the daofind task. The cursor
+command file shown below sets the fwhmpsf, sigma, and threshold parameters,
+located stars in the image, updates the parameter files, and quits the task.
+
+.nf
+        ap> type cmdfile
+        : fwhmpsf 2.5
+        : sigma 5.0
+        : threshold 10.0
+        \040
+        w
+        q
+
+        ap> daofind dev$ypix icommands=cmdfile verify-
+
+        ... full output will appear in ypix.coo.7
+.fi
+
+
+.ih
+TIME REQUIREMENTS
+
+.ih
+BUGS
+
+It is currently the responsibility of the user to make sure that the
+image displayed in the frame is the same as that specified by the image
+parameter.
+
+Commands which draw to the image display are disabled by default.
+To enable graphics overlay on the image display, set the display
+parameter to "imdr", "imdg", "imdb", or "imdy" to get red, green,
+blue or yellow overlays and set the findpars mkdetections switch to
+"yes". It may be necessary to run gflush and to redisplay the image
+to get the overlays position correctly.
+
+.ih
+SEE ALSO
+datapars, findpars
+.endhelp
diff --git a/noao/digiphot/apphot/doc/daofind.noao b/noao/digiphot/apphot/doc/daofind.noao
new file mode 100644
index 00000000..74cc8f00
--- /dev/null
+++ b/noao/digiphot/apphot/doc/daofind.noao
@@ -0,0 +1,21 @@
+
+
+There is a bug in the iraf/daophot ii daofind centering code which results in
+incorrect fractional pixel corrections being computed for the detected objects.
+This error can most easily be detected by plotting the histogram of the
+fractional pixel corrections for an image with a large number of detected
+objects. The histogram will be modulated at around the 20% level with "peaks"
+around the 0.33 and 0.66 fractional pixel values.
+
+This bug is fixed for the next release of iraf and in the external addon
+package digiphotx version of daofind. There is no workaround although it
+should be emphasized that this bug does not affect the centers computed by
+the psf fitting code in the peak, nstar, and allstar tasks. Users concerned
+with precision in the daofind results should upgrade their software, or
+recenter the objects with the phot "centroid" (fast) or "gauss" (more precise)
+routines.
+
+This bug is also present in the standalone version of daophot ii. I have
+reported this problem to Peter Stetson and he has fixed it.  Users concerned
+about this bug in the standalone version of daophot ii should obtain a fix
+from Peter Stetson.
diff --git a/noao/digiphot/apphot/doc/datapars.hlp b/noao/digiphot/apphot/doc/datapars.hlp
new file mode 100644
index 00000000..bacc5c77
--- /dev/null
+++ b/noao/digiphot/apphot/doc/datapars.hlp
@@ -0,0 +1,290 @@
+.help datapars May00 noao.digiphot.apphot
+.ih
+NAME
+datapars -- edit the data dependent parameters
+.ih
+USAGE
+datapars
+.ih
+PARAMETERS
+.ls scale = 1.0
+The scale of the image in user units, e.g arcseconds per pixel.
+All APPHOT distance dependent parameters are assumed to be in units of scale.
+If scale = 1.0 these parameters are assumed to be in units of pixels.
+Most APPHOT users should leave scale set to 1.0 unless they intend to
+compare their aperture photometry results directly with data 
+in the literature.
+.le
+.ls fwhmpsf = 2.5 (scale units)
+The full-width at half-maximum of the point spread function in scale units.
+The DAOFIND, FITPSF and WPHOT tasks and the "gauss" and "ofilter" centering
+algorithms depend on the value of fwhmpsf. APPHOT users can either determine
+a value for fwhmpsf using an external task such as IMEXAMINE, or make use of
+the interactive capabilities of the APPHOT tasks to set and store it.
+.le
+.ls emission = yes
+The features to be measured are above sky. By default the APPHOT package
+considers all features to be emission features. However all the package tasks
+measure absorption features if emission is set to no.
+.le
+.ls sigma = INDEF
+The standard deviation of the sky pixels. The DAOFIND task and the "constant"
+sky fitting algorithm error estimate depend on the value of sigma. APPHOT
+users should set sigma to a value which is representative of the noise
+in the sky background.
+.le
+.ls datamin = INDEF
+The minimum good pixel value. Datamin defaults to -MAX_REAL, the minimum
+floating point number supported by the host computer.  APPHOT users should
+set this parameter if they wish to remove bad data from the sky pixel
+distribution before the sky is fit or if they wish to flag stars with
+bad data in the centering and / or photometry apertures.
+.le
+.ls datamax = INDEF
+The maximum good pixel value. Datamax defaults to MAX_REAL the maximum
+floating point number supported by the host computer.
+APPHOT users should set this parameter if they wish to flag
+saturated stars or stars with bad data in the centering and / or
+photometry apertures.
+.le
+.ls noise = "poisson"
+The noise model used to estimate the uncertainties in the computed APPHOT
+magnitudes. The options are the following:
+.ls poisson
+Poisson statistics in the object and the sky background are used to estimate
+the error in the object measurement.  There are two components to the sky 
+noise measurement the sky noise in the object aperture and the mean error
+in the estimated sky value.
+.le
+.ls constant
+The standard deviation of the sky background is used to estimate the
+error in the object measurement.  There are two components to the error
+estimate the sky noise in the object aperture and the mean error in the
+estimated sky value.
+.le
+
+Most APPHOT users should use the Poisson model appropriate for CCD detectors.
+APPHOT users should also be aware that one or other of the parameters
+gain or epadu must be set correctly in order to compute the magnitude
+errors correctly.
+.le
+.ls ccdread = ""
+The image header keyword defining the readout noise parameter whose units are
+assumed to be electrons.
+.le
+.ls gain = ""
+The image header keyword defining the gain parameter whose units are assumed
+to be electrons per adu.
+.le
+.ls readnoise = 0.0
+The readout noise of the image in electrons.  APPHOT users should set this
+parameter or the ccdread parameter to its correct value before running any
+of the APPHOT tasks.
+.le
+.ls epadu = 1.0
+The gain in electrons per adu.  APPHOT users should set epadu or ain to its
+correct value before running any of the APPHOT tasks in order to insure that
+the magnitude error estimates are correct.
+.le
+.ls exposure = ""
+The image header exposure time keyword. The time units are arbitrary but
+must be consistent for any list of images whose magnitudes are to be compared.
+The computed magnitudes are normalized to 1 timeunit.  Setting the exposure
+parameter will greatly simplify  future reduction steps. The value of exposure
+is recorded in the APPHOT output file.
+.le
+.ls airmass = ""
+The image header airmass keyword.  The airmass parameter is not used
+directly by APPHOT but the airmass value is stored in the output file
+and its presence there will simplify future calibration steps.
+.le
+.ls filter = ""
+The image header filter id keyword.  The filter parameter is not used
+directly by APPHOT but the filter id is stored in the output file
+and its presence there will simplify future calibration steps.
+.le
+.ls obstime = ""
+The image header time of observation keyword. The obstime parameter is not used
+directly by APPHOT but the obstime value is stored in the output file
+and its presence there will simplify future calibration steps.
+.le
+.ls itime = 1.0
+The exposure time for the image in arbitrary units. The APPHOT magnitudes are
+normalized to 1 timeunit  using the value of exposure in the image header
+if exposure is defined or the value of itime.
+.le
+.ls xairmass = INDEF
+The airmass value.  The airmass is read from the image header if airmass
+is defined  or from xairmass. The airmass value is stored in the APPHOT
+output files.
+.le
+.ls ifilter = "INDEF"
+The filter id string. The filter id is read from the image header if filter
+is defined otherwise from ifilter. The filter id is stored in the APPHOT
+output files.
+.le
+.ls otime = "INDEF"
+The value of the time of observation. The time of observation is read from
+the image header if obstime is defined otherwise from otime. The time of
+observation is stored in the APPHOT output files.
+.le
+.ih
+DESCRIPTION
+\fIDatapars\fR sets the image data dependent parameters. These parameters are
+functions, of the instrument optics, the noise characteristics and range of
+linearity of the detector, and the observing conditions. Many of the
+centering, sky fitting, and photometry algorithm parameters in the CENTERPARS,
+FITSKYPARS and PHOTPARS  parameter sets scale with the data dependent
+parameters.
+
+The parameter \fIscale\fR sets the scale of the apertures used by the
+centering, sky fitting and photometry algorithms.  Scale converts radial
+distance measurements in pixel units to radial distance measurements in
+scale units. The APPHOT parameters, cbox, maxshift, rclean and rclip
+in the CENTERPARS parameter set; annulus, dannulus, and rgrow in
+the FITSKYPARS parameter set; and apertures in the PHOTPARS
+parameter set are expressed in units of the scale. The scale parameter is
+useful in cases where the observations are to be compared to published
+aperture photometry measurements in the literature.
+
+The parameter \fIfwhmpsf\fR defines the full-width at half-maximum of the
+stellar point spread function.  Most APPHOT tasks and algorithms do not 
+require this parameter. The exceptions are the DAOFIND task, the centering
+algorithms "gauss" and "ofilter", the FITPSF task, and the WPHOT task.
+
+By setting the \fIscale\fR and \fIfwhmpsf\fR appropriately the aperture
+sizes and radial distances may be  expressed in terms of the half-width
+at half-maximum of the stellar point spread function.  The way to do this
+is to define the scale parameter in units of the number of half-width at
+half-maximum per pixel, set the fwhmpsf parameter to 2.0, and then
+set the remaining scale dependent centering, sky fitting and photometry
+algorithm parameters in CENTERPARS, FITSKYPARS and PHOTPARS to
+appropriate values in units of the half-width at half-maximum of the
+point-spread function. Once an optimum set of algorithm parameters is
+chosen, the user need only alter the DATAPARS scale parameter before
+executing an APPHOT task on a new image.
+
+If  \fIemission\fR is "yes", the features to be measured are assumed to be
+above sky. By default the APPHOT package considers all measurements to
+be measurements of emission features. In most cases APPHOT users should
+leave emission set to "yes".
+
+The parameter \fIsigma\fR estimates the standard deviation of the sky
+background pixels. The star finding algorithm in DAOFIND uses sigma
+and the \fIfindpars.threshold\fR parameter to define the stellar
+detection threshold in adu. The centering algorithms uses sigma,
+1) with the \fIcenterpars.kclean\fR parameter to define deviant pixels
+if \fIcenterpars.clean\fR is enabled; 2) to estimate the signal to
+noise ratio in the centering box; 3) and with the \fIcenterpars.cthreshold\fR
+parameter to define the lower intensity limit for the pixels to be used
+for centering.  If sigma is undefined or <= 0.0 1) no cleaning is performed
+regardless of the value of centerpars.clean; 2) the background
+noise in the centering box is assumed to be 0; and 3) default cutoff
+intensity intensity is used for centering. 
+
+The \fIdatamin\fR and \fIdatamax\fR parameters define the  good data range.
+If datamin or datamax are defined bad data is removed from the sky pixel
+distribution before the sky is fit, data containing bad pixels in the 
+photometry apertures is flagged, and the corresponding aperture photometry
+magnitudes are set to INDEF. APPHOT users should set datamin and datamax
+to appropriate values before running the APPHOT tasks.
+
+Two noise models are available "constant" and "poisson". If \fInoise\fR =
+constant, the total noise is assumed to be due to noise in the sky background
+alone. If \fInoise\fR = poisson, the total noise includes Poisson noise from
+the object and the sky noise. 
+
+The parameters \fIgain\fR and \fIepadu\fR define the image gain.
+The gain parameter specifies which keyword in the image header contains
+the gain value. If gain is undefined or not present in the image header
+the value of epadu is used.  Epadu must be in units of electrons per adu.
+APPHOT users should set either gain or epadu before running any 
+APPHOT tasks to insure the magnitude error computations are correct.
+
+The two parameters \fIccdread\fR and \fIreadnoise\fR define the image
+readout noise.  The ccdread parameter specifies which keyword in the
+image header contains the readout noise value. If ccdread is undefined or
+not present in the image header the value of readnoise is used.
+Readnoise is assumed to be in units of electrons.
+APPHOT users should set either ccdread or readnoise before running any 
+APPHOT tasks to insure the magnitude error computations are correct.
+
+The magnitudes are normalized to an exposure time of 1 timeunit using
+the value of the exposure time in the image header parameter \fIexposure\fR
+or \fIitime\fR. If exposure is undefined or not present in the image header
+the value of itime is used. Itime can be in arbitrary units.
+Setting either exposure or itime will simplify future analysis steps.
+
+The parameters \fIairmass\fR and \fIxairmass\fR define the airmass
+of the observation. The airmass parameter specifies which keyword in the
+image header contains the airmass value. If airmass is undefined or
+not present in the image header the value of xairmass is used.
+The airmass values are not used in any APPHOT computations, however their
+presence in the APPHOT output files will simplify future reduction steps. 
+
+The parameters \fIfilter\fR and \fIifilter\fR define the filter
+of the observation. The filter parameter specifies which keyword in the
+image header contains the filter id. If filter is undefined or not present
+in the image header the value of ifilter is used. The filter id values are
+not used in any APPHOT computations, however their presence in the APPHOT
+output files can will simplify future reduction steps. 
+
+The parameters \fIobstime\fR and \fIotime\fR define the time 
+of the observation (e.g. UT). The obstime parameter specifies which keyword
+in the image header contains the time stamp of the observation. If obstime is
+undefined or not present in the image header the value of otime is used.
+The time of observations values are not used in any APPHOT 
+computations, however their presence in the APPHOT output files can
+greatly simplify future reduction steps. 
+
+.ih
+EXAMPLES
+
+1. List the data dependent parameters.
+
+.nf
+	ap> lpar datapars
+.fi
+
+2. Edit the data dependent parameters.
+
+.nf
+	ap> datapars
+.fi
+
+3. Edit the DATAPARS parameters from within the PHOT task.
+
+.nf
+    da> epar phot
+
+	... edit a few parameters
+
+	... move to the datapars parameter and type :e
+
+	... edit the datapars parameters and type :wq
+
+	... finish editing the phot parameters and type :wq
+.fi
+
+4. Save the current DATAPARS parameter set in a text file datnite1.par.
+This can also be done from inside a higher level task as in the
+previous example.
+
+.nf
+    da> datapars
+
+	... edit a few parameters
+
+	... type ":w datnite1.par"  from within epar
+.fi
+
+.ih
+TIME REQUIREMENTS
+
+.ih
+BUGS
+
+.ih
+SEE ALSO
+epar,lpar,daofind,center,fitsky,phot,wphot,polyphot,radprof,fitpsf
+.endhelp
diff --git a/noao/digiphot/apphot/doc/findpars.hlp b/noao/digiphot/apphot/doc/findpars.hlp
new file mode 100644
index 00000000..22fa7668
--- /dev/null
+++ b/noao/digiphot/apphot/doc/findpars.hlp
@@ -0,0 +1,134 @@
+.help findpars May00 noao.digiphot.apphot
+.ih
+NAME
+findpars -- edit the star detection parameters
+.ih
+USAGE
+findpars
+.ih
+PARAMETERS
+.ls threshold = 4.0 (sigma)
+The object detection threshold above local background in units of
+\fIdatapars.sigma\fR.
+.le
+.ls nsigma = 1.5
+The semi-major axis of the Gaussian convolution kernel used to computed the
+density enhancement and mean density images in Gaussian sigma. This semi-
+major axis is equal to min (2.0, 0.42466 * \fInsigma\fR *
+\fIdatapars.fwhmpsf\fR / \fIdatapars.scale\fR) pixels.
+.le
+.ls ratio = 1.0
+The ratio of the sigma of the Gaussian convolution kernel along the minor axis
+direction to the sigma along the major axis direction.  \fIRatio\fR defaults
+to 1.0 in which case the image is convolved with a circular Gaussian.
+.le
+.ls theta = 0.0
+The position angle of the major axis of the Gaussian convolution kernel.
+\fITheta\fR is measured in degrees counter-clockwise from the x axis.
+.le
+.ls sharplo = .2, sharphi = 1.0
+\fISharplo\fR and \fIsharphi\fR are numerical cutoffs on the image sharpness
+statistic designed to eliminate brightness maxima which are due to bad pixels
+rather than to astronomical objects.
+.le
+.ls roundlo = -1.0 roundhi = 1.0
+\fIRoundlo\fR and \fIroundhi\fR are numerical cutoffs on the image roundness
+statistic designed to eliminate brightness maxima which are due to bad rows or
+columns, rather than to astronomical objects.
+.le
+.ls mkdetections = no
+Mark the positions of the detected objects on the displayed image ?
+.le
+
+.ih
+DESCRIPTION
+
+DAOFIND approximates the stellar point spread function with an elliptical
+Gaussian function, whose sigma along the semi-major axis is 0.42466 *
+\fIdatapars.fwhmpsf\fR / \fIdatapars.scale\fR pixels, semi-minor to semi-major
+axis ratio is \fIratio\fR, and major axis position angle is \fItheta\fR.
+Using this model, a convolution kernel, truncated at \fInsigma\fR sigma,
+and normalized to sum to zero, is constructed.
+
+The density enhancement image \fIstarmap\fR is computed by convolving the input
+image with the Gaussian kernel. This operation is mathematically equivalent to
+fitting, in the least-squares sense, the image data at each point with a
+truncated, lowered elliptical Gaussian function. After convolution each point
+in \fIstarmap\fR contains as estimate of the amplitude of the best fitting
+Gaussian function at that point. Each point in \fIskymap\fR, if the user
+chooses to compute it, contains an estimate of the best fitting sky value
+at that point.
+
+After image convolution DAOFIND steps through \fIstarmap\fR searching
+for density enhancements greater than \fIfindpars.threshold\fR *
+\fIdatapars.sigma\fR, and brighter than all other density enhancements
+within a semi-major axis of 0.42466 \fIfindpars.nsigma\fR *
+\fIdatapars.fwhmpsf\fR. As the program selects candidates, it computes two
+shape characteristics sharpness and roundness.  The sharpness statistic
+measures the ratio of the difference between the height of the central pixel
+and the mean of the surrounding non-bad pixels, to the height of the best
+fitting Gaussian function at that point. The roundness statistics measures
+the ratio of, the difference in the height of the best fitting Gaussian
+function in x minus the best fitting Gaussian function in y, over the average
+of the best fitting Gaussian functions in x and y. The limits on these
+parameters \fIfindpars.sharplo\fR, \fIfindpars.sharphi\fR,
+\fIfindpars.roundlo\fR, and \fIfindpars.roundhi\fR, are set to weed out
+non-astronomical objects and brightness enhancements that are elongated in
+x and y respectively.
+
+Lastly the x and y centroids of the detected objects are computed by
+estimating the x and y positions of the best fitting 1D Gaussian
+functions in x and y respectively, a rough magnitude is estimated
+by computing the ratio of the amplitude of the best fitting Gaussian at
+the object position to \fIfindpars.threshold\fR * \fIdatapars.sigma\fR,
+and the object is added to the output coordinate file.
+
+
+.ih
+EXAMPLES
+
+1. List the object detection parameters.
+
+.nf
+	da> lpar findpars
+.fi
+
+2. Edit the object detection parameters.
+
+.nf
+	da> findpars
+.fi
+
+3. Edit the FINDPARS parameters from within the DAOFIND task.
+
+.nf
+	da> epar daofind
+
+	    ... edit a few daofind parameters
+
+	    ... move to the findpars parameter and type :e
+
+	    ... edit the findpars parameter and type :wq
+
+	    ... finish editing the daofind parameters and type :wq
+.fi
+
+4. Save the current FINDPARS parameter set in a text file fndnite1.par.
+This can also be done from inside a higher level task as in the previous
+example.
+
+.nf
+	da> findpars
+
+	    ... edit the parameters
+
+	    ... type ":w fndnite1.par" from within epar
+.fi
+
+.ih
+BUGS
+
+.ih
+SEE ALSO
+daofind, datapars
+.endhelp
diff --git a/noao/digiphot/apphot/doc/fitpsf.hlp b/noao/digiphot/apphot/doc/fitpsf.hlp
new file mode 100644
index 00000000..8a229508
--- /dev/null
+++ b/noao/digiphot/apphot/doc/fitpsf.hlp
@@ -0,0 +1,680 @@
+.help fitpsf May00 noao.digiphot.apphot
+.ih
+NAME
+fitpsf -- model the point spread function with an analytic function
+.ih
+USAGE
+fitpsf image box
+.ih
+PARAMETERS
+.ls image
+The list of images containing the objects to be measured.
+.le
+.ls box    
+The width of the fitting box in scale units.
+.le
+.ls coords = ""
+The list of text files containing initial coordinates for the objects to
+be centered. Objects are listed in coords one object per line with the
+initial coordinate values in columns one and two. The number of coordinate
+files must be zero, one, or equal to the number of images.
+If coords is "default", "dir$default", or a directory specification then an
+coords file name of the form dir$root.extension.version is constructed and
+searched for, where dir is the directory, root is the root image name,
+extension is "coo" and version is the next available version number for the
+file.
+.le
+.ls output = "default"
+The name of the results file or results directory. If output is
+"default", "dir$default", or a directory specification then an output file name
+of the form dir$root.extension.version is constructed, where dir is the
+directory, root is the root image name, extension is "psf" and version is
+the next available version number for the file. The number of output files
+must be zero, one, or equal to the number of image files.  In both interactive
+and batch mode full output is written to output. In interactive mode
+an output summary is also written to the standard output.
+.le
+.ls datapars = ""
+The name of the file containing the data dependent parameters.
+The critical parameters \fIfwhmpsf\fR and \fIsigma\fR are located in
+datapars.  If datapars is undefined then the default parameter set in
+uparm directory is used.
+.le
+.ls function = "radgauss"
+The function to be fit. The options are:
+.ls radgauss
+A 2D radial Gaussian function is fit. The parameters of the fitting function
+are: x and y center, sigma of the Gaussian, amplitude of the Gaussian and
+the local sky value.
+.le
+.ls elgauss
+A 2D elliptical Gaussian function is fit. The parameters of the fitting
+function are: x and y center, x and y sigma of the Gaussian, amplitude of
+the Gaussian and the local sky value.
+.le
+.ls moments
+The 0th, 1st and 2nd order moments are computed and used to derive
+estimates of the
+x and y center values, radius of gyration, ellipticity and position
+angle of the object.
+.le
+.le
+.ls maxiter = 50
+The maximum number of iterations that the non-linear fitting routines will
+perform in an attempt to find a satisfactory fit.
+.le
+.ls nreject = 0
+The maximum number of rejection cycles performed after the fit.
+The default is no rejection.
+.le
+.ls kreject = 3.0
+The k-sigma rejection limit in units of sigma.
+.le
+.ls mkbox = no
+Draw the fitting box on the image display?
+.le
+.ls interactive = yes
+Run the task interactively ?
+.le
+.ls icommands = ""
+The image cursor or image cursor command file.
+.le
+.ls gcommands = ""
+The graphics cursor or graphics cursor command file.
+.le
+.ls wcsin = ")_.wcsin", wcsout = ")_.wcsout"
+The coordinate system of the input coordinates read from \fIcoords\fR and
+of the output coordinates written to \fIoutput\fR respectively. The image
+header coordinate system is used to transform from the input coordinate
+system to the "logical" pixel coordinate system used internally,
+and from the internal "logical" pixel coordinate system to the output
+coordinate system. The input coordinate system options are "logical", tv",
+"physical", and "world". The output coordinate system options are "logical",
+"tv", and "physical". The image cursor coordinate system is assumed to
+be the "tv" system.
+.ls logical
+Logical coordinates are pixel coordinates relative to the current image.
+The  logical coordinate system is the coordinate system used by the image
+input/output routines to access the image data on disk. In the logical
+coordinate system the coordinates of the first pixel of a  2D image, e.g.
+dev$ypix  and a 2D image section, e.g. dev$ypix[200:300,200:300] are
+always (1,1).
+.le
+.ls tv
+Tv coordinates are the pixel coordinates used by the display servers. Tv
+coordinates  include  the effects of any input image section, but do not
+include the effects of previous linear transformations. If the input
+image name does not include an image section, then tv coordinates are
+identical to logical coordinates.  If the input image name does include a
+section, and the input image has not been linearly transformed or copied from
+a parent image, tv coordinates are identical to physical coordinates.
+In the tv coordinate system the coordinates of the first pixel of a
+2D image, e.g. dev$ypix and a 2D image section, e.g. dev$ypix[200:300,200:300]
+are (1,1) and (200,200) respectively.
+.le
+.ls physical
+Physical coordinates are pixel coordinates invariant  with respect to linear
+transformations of the physical image data.  For example, if the current image
+was created by extracting a section of another image,  the  physical
+coordinates of an object in the current image will be equal to the physical
+coordinates of the same object in the parent image,  although the logical
+coordinates will be different.  In the physical coordinate system the
+coordinates of the first pixel of a 2D image, e.g. dev$ypix and a 2D
+image section, e.g. dev$ypix[200:300,200:300] are (1,1) and (200,200)
+respectively.
+.le
+.ls world
+World coordinates are image coordinates in any units which are invariant
+with respect to linear transformations of the physical image data. For
+example, the ra and dec of an object will always be the same no matter
+how the image is linearly transformed. The units of input world coordinates
+must be the same as those expected by the image header wcs, e. g.
+degrees and degrees for celestial coordinate systems.
+.le
+The wcsin and wcsout parameters default to the values of the package
+parameters of the same name. The default values of the package parameters
+wcsin and wcsout are "logical" and "logical" respectively.
+.le
+.le
+.ls cache = ")_.cache"
+Cache the image pixels in memory. Cache may be set to the value of the apphot
+package parameter (the default), "yes", or "no". By default cacheing is 
+disabled.
+.le
+.ls verify = ")_.verify"
+Verify the critical parameters in non-interactive mode ? Verify may be set to
+the apphot package parameter value (the default), "yes", or "no.
+.le
+.ls update = ")_.update"
+Update the critical parameters in non-interactive mode if verify is set of
+"yes" ? Update may be set to the apphot package parameter value (the default),
+"yes", or "no.
+
+.le
+.ls verbose = ")_.verbose"
+Print messages on the terminal in non-interactive mode ? Verbose may be set
+to the apphot package parameter value (the default), "yes", or "no.
+
+.le
+.ls graphics = ")_.graphics"
+The default graphics device.  Graphics may be set to the apphot package
+parameter value (the default), "yes", or "no.
+.le
+.ls display = ")_.display"
+The default display device.  Display may be set to the apphot package
+parameter value (the default), "yes", or "no.  By default graphics overlay
+is disabled.  Setting display to one of "imdr", "imdg", "imdb", or "imdy"
+enables graphics overlay with the IMD graphics kernel.  Setting display to
+"stdgraph" enables FITPSF to work interactively from a contour plot.
+.le
+
+.ih
+DESCRIPTION
+
+FITPSF models the stellar brightness distribution of objects in the IRAF image
+\fIimage\fR using non-linear least squares techniques and writes the
+list of model parameters and associated errors to the file \fIoutput\fR.
+Initial coordinates for the objects are read from the image cursor or
+the text file \fIcoords\fR.  Pixels in a subraster of width \fIbox * scale\fR
+are extracted and used in the fit.
+
+The coordinates read from \fIcoords\fR are assumed to be in coordinate
+system defined by \fIwcsin\fR. The options are "logical", "tv", "physical",
+and "world" and the transformation from the input coordinate system to
+the internal "logical" system is defined by the image coordinate system.
+The simplest default is the "logical" pixel system. Users working on with
+image sections but importing pixel coordinate lists generated from the parent
+image must use the "tv" or "physical" input coordinate systems.
+Users importing coordinate lists in world coordinates, e.g. ra and dec,
+must use the "world" coordinate system and may need to convert their
+equatorial coordinate units from hours and degrees to degrees and degrees first.
+
+The coordinates written to \fIoutput\fR are in the coordinate
+system defined by \fIwcsout\fR. The options are "logical", "tv",
+and "physical". The simplest default is the "logical" system. Users
+wishing to correlate the output coordinates of objects measured in
+image sections or mosaic pieces with coordinates in the parent
+image must use the "tv" or "physical" coordinate systems.
+
+If \fIcache\fR is yes and the host machine physical memory and working set size
+are large enough, the input image pixels are cached in memory. If cacheing
+is enabled and FITPSF is run interactively the first measurement will appear
+to take a long time as the entire image must be read in before the measurement
+is actually made. All subsequent measurements will be very fast because FITPSF
+is accessing memory not disk. The point of cacheing is to speed up random
+image access by making the internal image i/o buffers the same size as the
+image itself. However if the input object lists are sorted in row order and
+sparse cacheing may actually worsen not improve the execution time. Also at
+present there is no point in enabling cacheing for images that are less than
+or equal to 524288 bytes, i.e. the size of the test image dev$ypix, as the
+default image i/o buffer is exactly that size. However if the size of dev$ypix
+is doubled by converting it to a real image with the chpixtype task then the
+effect of cacheing in interactive is can be quite noticeable if measurements
+of objects in the top and bottom halfs of the image are alternated.
+
+FITPSF can be run either interactively or in batch mode by setting the
+parameter \fIinteractive\fR. In interactive mode starting x and y positions
+can either be read directly from the image cursor or read from the text
+file specified by \fIcoords\fR. In batch mode the estimated
+positions can be read from the text file \fIcoords\fR or the image cursor
+parameter \fIicommands\fR can be redirected to a text file containing
+a list of cursor commands.
+
+.ih
+CURSOR COMMANDS
+
+The currently available cursor commands are listed below.
+
+.nf
+	       Interactive Keystroke Commands
+
+?	Print help
+:	Colon commands
+v	Verify the critical parameters
+w	Save the current parameters
+d	Plot radial profile of current star 
+i	Interactively set parameters using current star
+f	Fit current star
+spbar	Fit current star, output results
+m	Move to next star in coordinate list
+n	Fit next star in coordinate list, output results
+l	Fit remaining stars in coordinate list, output results
+e	Print error messages
+r	Rewind the coordinate list
+q	Exit task 
+
+
+
+                 Colon Commands
+
+:show	[data/fit]	List the parameters
+:m [n]	Move to next [nth] star in coordinate list
+:n [n]	Fit next [nth] star in coordinate list, output results
+
+
+		Colon Parameter Editing Commands
+
+# Image and file name parameters
+
+:image		[string]	Image name
+:coords		[string]	Coordinate file name
+:output		[string]	Output file name
+
+# Data dependent parameters
+
+:scale		[value]		Image scale (units per pixel)
+:fwhmpsf	[value]		Scale factor (scale units)		
+:emission	[y/n]		Emission feature (y), absorption (n)
+:sigma		[value]		Standard deviation of sky (counts)
+:datamin	[value]		Minimum good data value (counts)
+:datamax	[value]		Maximum good data value (counts)
+
+# Noise description parameters
+
+:noise		[string]	Noise model (constant|poisson)
+:gain		[string]	Gain image header keyword
+:ccdread	[string]	Readout noise image header keyword
+:epadu		[value]		Gain (electrons  per adu)
+:readnoise	[value]		Readnoise (electrons)
+
+# Observation parameters
+
+:exposure	[string]	Exposure time image header keyword
+:airmass	[string]	Airmass image header keyword
+:filter		[string]	Filter image header keyword
+:obstime	[string]        Time of observation image header keyword
+:itime		[value]		Exposure time (time units)
+:xairmass	[value]		Airmass value (number)
+:ifilter	[string]	Filter id string
+:otime		[string]	Time of observation (time units)
+
+# Fitting parameters
+
+:function	[string]	PSF model (radgauss|elgauss|moments)
+:box		[value]		Width of the fitting box (scale units)
+:maxiter	[value]		Maximum number of iterations
+:nreject	[value]		Maximum number of rejection cycles
+:kreject	[value]		Rejection limit (sigma)
+
+# Plotting and marking functions
+
+:mkbox		[y/n]		Mark the fitting box on the display
+
+
+The following command are available from within the interactive setup menu.
+
+
+                    Interactive Fitpsf Setup Menu
+
+	v	Mark and verify the critical fitpsf parameters (f,s,b)
+
+	f	Mark and verify the full-width half-maximum of the psf
+	s	Mark and verify the standard deviation of the background
+	l	Mark and verify the minimum good data value
+	u	Mark and verify the maximum good data value
+
+	b	Mark and verify the half-width of the fitting box
+.fi
+
+.ih
+ALGORITHMS
+
+The fitting parameters are \fIfunction\fR, the functional form of the model
+to be fit, \fImaxiter\fR, the maximum number of iterations per fit,
+\fIkreject\fR, the K-sigma rejection limit and \fInreject\fR, the maximum
+number of rejection cycles. The currently available functions are a 2D
+moments analysis "moments", a 2D radial Gaussian "radgauss",  and a
+2D elliptical Gaussian "elgauss".
+
+The weighting of the fit is determined by the parameter \fInoise\fR in the 
+\fIdatapars\fR file. The two options are \fIconstant\fR, in which all the
+weights are set to 1 and \fIpoisson\fR in which the weights are equal to
+the inverse of the counts divided by the image gain read from the datapars
+\fIgain\fR or \fIepadu\fR parameters plus the square of the readout noise
+determined from the datapars parameters \fIccdread\fR or \fIreadnoise\fR.
+If \fIfunction\fR is either "radgauss" or "ellgauss" then the datapars
+parameter \fIfwhmpsf\fR is used to determine the initial guess for the
+Gaussian sigma.  The datapars parameter \fIthreshold\fR determines the
+intensity threshold above which the moment analysis is performed.
+
+.ih
+OUTPUT
+
+In interactive mode the following quantities are printed on the
+terminal as shown below, for the radial Gaussian, elliptical Gaussian and
+moments functions respectively.
+
+.nf
+    image  xcenter  ycenter  rsigma  amplitude  sky  err
+
+    image  xcenter  ycenter  xsigma  ysigma rot  amplitude  sky  err
+
+    image  xcenter  ycenter  rgyrat  ellip  pa amplitude  sky  err
+
+.fi
+
+In both interactive and batch mode the full output is written to the
+text file \fIoutput\fR. At the beginning of each file is a header
+listing the values of the parameters when the first stellar
+record was written. These parameters can be subsequently altered.
+For each star measured the following record is written for the radial
+Gaussian, elliptical Gaussian, and moments functions respectively.
+
+.nf
+        image  xinit  yinit  id  coords  lid
+    	    xcenter  ycenter  rsigma  amplitude  sky
+	    excenter eycenter ersigma eamplitude esky  ier  error
+
+        image  xinit  yinit  id  coords  lid
+    	    xcenter  ycenter  xsigma  ysigma  rot  amplitude  sky
+	    excenter eycenter exsigma eysigma erot eamplitude esky  ier\
+	    error
+
+        image  xinit  yinit  id  coords  lid
+	    xcenter  ycenter  rgyrat  ellip  pa amplitude  sky
+	    excenter eycenter ergyrat eellip epa eamplitude esky  ier\
+	    error
+.fi
+
+Image and coords are the name of the image and coordinate files respectively.
+Id and lid are the sequence numbers of stars in the output and coordinate
+files respectively and xinit and yinit are the initial positions.
+Xcenter and ycenter are the computed x and y
+positions of the object. Rsigma, xsigma and ysigma are the distance from
+the center of the Gaussian at which the Gaussian is equal to exp (-0.5)
+of its central value. Xsigma and ysigma refer to those values along the major
+and minor axes of the ellipse respectively. The amplitude and sky refer to
+the amplitude of
+the Gaussian function and a constant background value respectively.
+If function = "moments" amplitude and sky refer to the total intensity
+above threshold and sky is the threshold value. Rot and pa are position angles
+of the major axis measured counter-clockwise with respect to the x axis.
+Rgyrat is the radius
+of gyration of the object and ellip its ellipticity.
+Quantities prefixed by an e represent the errors in the corresponding
+fitted parameters.
+
+.ih
+ERRORS
+
+If all went well in the fitting process the error code stored in the ier
+field described above is 0. Non-zero values of ier flag the following error
+conditions.
+
+.nf
+          0     # No error
+	401     # The fitting box is off the image
+	402     # The fitting box is partially off the image
+	403     # There are too few points to fit the function
+	404     # The fit is singular
+	405     # The fit did not converge
+.fi
+
+.ih
+EXAMPLES
+
+1. Compute the radial Gaussian function parameters for a few  stars in dev$ypix
+using the display and the image cursor. Setup the task parameters using
+the interactive setup menu defined by the i key command. Use uniform
+weighting.
+
+.nf
+	ap> display dev$ypix 1 fi+
+
+	... display the image
+
+	ap> fitpsf dev$ypix 11 noise=constant
+
+	... type ? to see the help screen
+
+	... move the image cursor to a star
+	... type i to enter the interactive setup menu
+	... enter maximum radius in pixels of the radial profile or type
+	    CR to accept the default value
+	... set the fitting box width, fwhmpsf, and sigma using the graphics
+	    cursor and the stellar radial profile plot
+	... typing <CR> leaves everything at the default value
+	... type q to quit the setup menu
+
+	... type the v key to verify the parameters
+
+	... type the w key to save the parameters in the parameter files
+
+	... move the image cursor to the stars of interest and tap
+	    the space bar
+
+	... a one line summary of the fitted parameters will appear on the
+	    standard output for each star measured
+
+	... type q to quit and another q to confirm the quit
+
+	... the full output will appear in ypix.psf.1
+.fi
+
+2. Compute the radial Gaussian function  parameters for a few  stars in 
+dev$ypix using the contour plot and the graphics cursor. Setup the task
+parameters using the interactive setup menu defined by the i key command.
+Use uniform weighting.
+
+.nf
+	ap> show stdimcur
+
+	... save the current value of stdimcur
+
+	ap> set stdimcur = stdgraph
+
+	... define the image cursor to be the graphics cursor
+
+	ap> contour dev$ypix >G ypix.plot1
+
+	... store the contour plot of dev$ypix in the file ypix.plot1
+
+	ap> fitpsf dev$ypix 11.0 noise=constant display=stdgraph
+
+	... type ? to get a short help page on the screen
+
+	... move the graphics cursor to a star
+	... type i to enter the interactive setup menu
+	... enter the maximum radius in pixels of the radial profile or
+	    type CR to accept the default value
+	... set the fitting box width, fwhmpsf, and sigma using the graphics
+	    cursor and the stellar radial profile plot
+	... typing <CR> leaves everything at the default value
+	... type q to quit the setup menu
+
+	... type the v key to verify critical parameters
+
+	... type the w key to save the parameters in the parameter files
+
+	... retype :.read ypix.plot1 to reload the contour plot
+
+	... move the graphics cursor to the stars of interest and tap
+	    the space bar
+
+	... a one line summary of the fitted parameters will appear on the
+	    standard output for each star measured
+
+	... type q to quit and q again to confirm the quit
+
+	... full output will appear in the text file ypix.psf.2 
+.fi
+
+
+3. Setup and run FITPSF interactively on a list of objects temporarily
+overriding the fwhmpsf and sigma parameters determined in examples 1 or 2.
+Use uniform weighting.
+
+.nf
+        ap> daofind dev$ypix fwhmpsf=2.6 sigma=25.0 verify-
+
+        ... make a coordinate list
+
+        ... the output will appear in the text file ypix.coo.1
+
+        ap> fitpsf dev$ypix 11.0 fwhmpsf=2.6 noise=constant coords=ypix.coo.1
+
+        ... type ? for optional help
+
+
+        ... move the graphics cursor to the stars and tap space bar
+
+                                or
+
+        ... select stars from the input coordinate list with m / :m #
+            and measure with spbar
+
+        ... measure stars selected from the input coordinate list
+            with n / n #
+
+        ... a one line summary of results will appear on the standard output
+            for each star measured
+
+        ... type q to quit and q again to confirm the quit
+
+        ... the output will appear in ypix.psf.3 ...
+.fi
+
+
+4. Display and fit some stars in an image section and write the output
+coordinates in the coordinate system of the parent image. Use uniform 
+weighting.
+
+.nf
+        ap> display dev$ypix[150:450,150:450] 1
+
+        ... display the image section
+
+        ap> fitpsf dev$ypix[150:450,150:450] 11.0 noise=constant wcsout=tv
+
+        ... move cursor to stars and type spbar
+
+        ... type q to quit and q again to confirm quit
+
+        ... output will appear in ypix.psf.4
+
+        ap> pdump ypix.psf.4 xc,yc yes | tvmark 1 STDIN col=204
+.fi
+
+
+5. Run FITPSF in batch mode using the coordinate file and the previously
+saved parameters. Use uniform weighting. Verify the critical parameters.
+
+.nf
+        ap> fitpsf dev$ypix 11.0 coords=ypix.coo.1 noise=constant verify+ \
+            inter-
+
+        ... output will appear in ypix.psf.5 ...
+.fi
+
+6. Repeat example 5 but assume that the input coordinate are ra and dec
+in degrees and degrees, turn off verification, and submit the task to to
+the background. Use uniform weighting.
+
+.nf
+        ap> display dev$ypix 1
+
+        ap> rimcursor wcs=world > radec.coo
+
+        ... move to selected stars and type any key
+
+        ... type ^Z to quit
+
+        ap> fitpsf dev$ypix 11.0 coords=radec.coo noise=constant \
+            wcsin=world verify- inter- &
+
+        ... output will appear in ypix.psf.6
+
+        ap> pdump ypix.psf.6 xc,yc yes | tvmark 1 STDIN col=204
+
+        ... mark the stars on the display
+.fi
+
+7. Run FITPSF interactively without using the image display.
+
+.nf
+        ap> show stdimcur
+
+        ... record the default value of stdimcur
+
+        ap> set stdimcur = text
+
+        ... set the image cursor to the standard input
+
+        ap> fitpsf dev$ypix 11.0 coords=ypix.coo.1 noise=constant
+
+        ... type ? for optional help
+
+        ... type :m 3 to set the initial coordinates to those of the
+            third star in the list
+
+        ... type i to enter the interactive setup menu
+        ... enter the maximum radius in pixels for the radial profile or
+            accept the default with a CR
+        ... type v to enter the default menu
+        ... set the fwhmpsf, sigma, and fitting box size  using the
+            graphics cursor and the stellar radial profile plot
+        ... typing <CR> after the prompt leaves the parameter at its default
+            value
+        ... type q to quit the setup menu
+
+        ... type r to rewind the coordinate list
+
+        ... type l to measure all the stars in the coordinate list
+
+        ... a one line summary of the answers will appear on the standard
+            output for each star measured
+
+        ... type q to quit followed by q to confirm the quit
+
+        ... full output will appear in the text file ypix.psf.7
+
+        ap> set stdimcur = <default>
+
+        ... reset the value of stdimcur
+.fi
+
+8. Use an image cursor command file to drive the FITPSF task. The cursor command
+file shown below sets the fwhmpsf, sigma, and noise, computes the model
+fit parameter values for 3 stars, updates the parameter files, and quits
+the task.
+
+.nf
+        ap> type cmdfile
+        : fwhmpsf 2.6
+        : sigma 5.0
+        : noise constant
+        442 410 101 \040
+        349 188 101 \040
+        225 131 101 \040
+        w
+        q
+
+        ap> fitpsf dev$ypix 11.0 icommands=cmdfile verify-
+
+        ... full output will appear in ypix.psf.8
+.fi
+
+
+.ih
+BUGS
+
+In interactive mode the user should not change the type function to be fit
+after the first record is written to the output file. In this case the file
+header and record structure will not match.
+
+It is currently the responsibility of the user to make sure that the
+image displayed in the frame is the same as that specified by the image
+parameter.
+
+Commands which draw to the image display are disabled by default.
+To enable graphics overlay on the image display, set the display
+parameter to "imdr", "imdg", "imdb", or "imdy" to get red, green,
+blue or yellow overlays and set the  mkbox switch to"yes".
+It may be necessary to run gflush and to redisplay the image
+to get the overlays position correctly.
+
+.ih
+SEE ALSO
+
+datapars, radprof
+.endhelp
diff --git a/noao/digiphot/apphot/doc/fitsky.hlp b/noao/digiphot/apphot/doc/fitsky.hlp
new file mode 100644
index 00000000..5fc07de9
--- /dev/null
+++ b/noao/digiphot/apphot/doc/fitsky.hlp
@@ -0,0 +1,632 @@
+.help fitsky Dec92 noao.digiphot.apphot
+.ih
+NAME
+fitsky - determine the mode, sigma and skew of the sky pixels
+.ih
+USAGE
+fitsky image
+.ih
+PARAMETERS
+.ls image
+The list of images containing the sky regions to be fit.
+.le
+.ls coords = ""
+The list of text files containing initial coordinates for the objects to
+be centered. Objects are listed in coords one object per line with the
+initial coordinate values in columns one and two. The number of coordinate
+files must be zero, one, or equal to the number of images.
+If coords is "default", "dir$default", or a directory specification then an
+coords file name of the form dir$root.extension.version is constructed and
+searched for, where dir is the directory, root is the root image name,
+extension is "coo" and version is the next available version number for the
+file.
+.le
+.ls output = "default"
+The name of the results file or results directory. If output is
+"default", "dir$default", or a directory specification then an output file name
+of the form dir$root.extension.version is constructed, where dir is the
+directory, root is the root image name, extension is "sky" and version is
+the next available version number for the file. The number of output files
+must be zero, one, or equal to the number of image files.  In both interactive
+and batch mode full output is written to output. In interactive mode
+an output summary is also written to the standard output.
+.le
+.ls plotfile = ""
+The name of the file containing radial profile plots of the stars written
+to the output file. If plotfile is defined then a radial profile plot
+is written to plotfile every time a record is written to \fIoutput\fR.
+The user should be aware that this can be a time consuming operation.
+.le
+.ls datapars = ""
+The name of the file containing the data dependent parameters.
+The critical parameters \fIfwhmpsf\fR and \fIsigma\fR are located in
+datapars.  If datapars is undefined then the default parameter set in
+uparm directory is used.
+.le
+.ls fitskypars = ""
+The name of the text file containing the sky fitting parameters. The critical
+parameters \fIsalgorithm\fR, \fIannulus\fR, and \fIdannulus\fR are located here.
+If \fIfitskypars\fR is undefined then the default parameter set in uparm
+directory is used.
+.le
+.ls interactive = yes
+Run the task interactively ?
+.le
+.ls radplots = no
+If \fIradplots\fR is "yes" and PHOT is run in interactive mode, a radial
+profile of each star is plotted on the screen after the star is measured.
+.le
+.ls icommands = ""
+The image display cursor or image cursor command file.
+.le
+.ls gcommands = ""
+The graphics cursor or graphics cursor command file.
+.le
+.ls wcsin = ")_.wcsin", wcsout = ")_.wcsout"
+The coordinate system of the input coordinates read from \fIcoords\fR and
+of the output coordinates written to \fIoutput\fR respectively. The image
+header coordinate system is used to transform from the input coordinate
+system to the "logical" pixel coordinate system used internally,
+and from the internal "logical" pixel coordinate system to the output
+coordinate system. The input coordinate system options are "logical", tv",
+"physical", and "world". The output coordinate system options are "logical",
+"tv", and "physical". The image cursor coordinate system is assumed to
+be the "tv" system.
+.ls logical
+Logical coordinates are pixel coordinates relative to the current image.
+The  logical coordinate system is the coordinate system used by the image
+input/output routines to access the image data on disk. In the logical
+coordinate system the coordinates of the first pixel of a  2D image, e.g.
+dev$ypix  and a 2D image section, e.g. dev$ypix[200:300,200:300] are
+always (1,1).
+.le
+.ls tv
+Tv coordinates are the pixel coordinates used by the display servers. Tv
+coordinates  include  the effects of any input image section, but do not
+include the effects of previous linear transformations. If the input
+image name does not include an image section, then tv coordinates are
+identical to logical coordinates.  If the input image name does include a
+section, and the input image has not been linearly transformed or copied from
+a parent image, tv coordinates are identical to physical coordinates.
+In the tv coordinate system the coordinates of the first pixel of a
+2D image, e.g. dev$ypix and a 2D image section, e.g. dev$ypix[200:300,200:300]
+are (1,1) and (200,200) respectively.
+.le
+.ls physical
+Physical coordinates are pixel coordinates invariant  with respect to linear
+transformations of the physical image data.  For example, if the current image
+was created by extracting a section of another image,  the  physical
+coordinates of an object in the current image will be equal to the physical
+coordinates of the same object in the parent image,  although the logical
+coordinates will be different.  In the physical coordinate system the
+coordinates of the first pixel of a 2D image, e.g. dev$ypix and a 2D
+image section, e.g. dev$ypix[200:300,200:300] are (1,1) and (200,200)
+respectively.
+.le
+.ls world
+World coordinates are image coordinates in any units which are invariant
+with respect to linear transformations of the physical image data. For
+example, the ra and dec of an object will always be the same no matter
+how the image is linearly transformed. The units of input world coordinates
+must be the same as those expected by the image header wcs, e. g.
+degrees and degrees for celestial coordinate systems.
+.le
+The wcsin and wcsout parameters default to the values of the package
+parameters of the same name. The default values of the package parameters
+wcsin and wcsout are "logical" and "logical" respectively.
+.le
+.le
+.ls cache = ")_.cache"
+Cache the image pixels in memory. Cache may be set to the value of the apphot
+package parameter (the default), "yes", or "no". By default cacheing is 
+disabled.
+.le
+.ls verify = ")._verify"
+Verify the critical parameters in non-interactive mode ? Verify may be set to
+ the apphot package parameter value (the default), "yes", or "no.
+.le
+.ls update = ")_.update"
+Update the critical parameters in non-interactive mode if verify is yes ?
+Update may be set to the apphot package parameter value (the default), "yes",
+or "no.
+
+.le
+.ls verbose = ")_.verbose"
+Print messages on the terminal in non-interactive mode ? Verbose may be set to
+the apphot package parameter value (the default), "yes", or "no.
+
+.le
+.ls graphics = ")_.graphics"
+The default graphics device.  Graphics may be set to the apphot package
+parameter value (the default), "yes", or "no.
+.le
+.ls display = ")_.display"
+The default display device. Display may be set to the apphot package parameter
+value (the default), "yes", or "no. By default graphics overlay is disabled.
+Setting display to one of "imdr", "imdg", "imdb", or "imdy" enables graphics
+overlay with the IMD graphics kernel.  Setting display to "stdgraph" enables
+FITSKY to work interactively from a contour plot.
+.le
+
+.ih
+DESCRIPTION
+FITSKY computes accurate sky values for a set of objects in the IRAF image
+\fIimage\fR, whose coordinates are read from the text file \fIcoords\fR or
+the image display cursor, and writes the computed sky values to the text
+file \fIoutput\fR.
+
+The coordinates read from \fIcoords\fR are assumed to be in coordinate
+system defined by \fIwcsin\fR. The options are "logical", "tv", "physical",
+and "world" and the transformation from the input coordinate system to
+the internal "logical" system is defined by the image coordinate system.
+The simplest default is the "logical" pixel system. Users working on with
+image sections but importing pixel coordinate lists generated from the parent
+image must use the "tv" or "physical" input coordinate systems.
+Users importing coordinate lists in world coordinates, e.g. ra and dec,
+must use the "world" coordinate system and may need to convert their
+equatorial coordinate units from hours and degrees to degrees and degrees first.
+
+The coordinates written to \fIoutput\fR are in the coordinate
+system defined by \fIwcsout\fR. The options are "logical", "tv",
+and "physical". The simplest default is the "logical" system. Users
+wishing to correlate the output coordinates of objects measured in
+image sections or mosaic pieces with coordinates in the parent
+image must use the "tv" or "physical" coordinate systems.
+
+If \fIcache\fR is yes and the host machine physical memory and working set size
+are large enough, the input image pixels are cached in memory. If cacheing
+is enabled and FITSKY is run interactively the first measurement will appear
+to take a long time as the entire image must be read in before the measurement
+is actually made. All subsequent measurements will be very fast because FITSKY
+is accessing memory not disk. The point of cacheing is to speed up random
+image access by making the internal image i/o buffers the same size as the
+image itself. However if the input object lists are sorted in row order and
+sparse cacheing may actually worsen not improve the execution time. Also at
+present there is no point in enabling cacheing for images that are less than
+or equal to 524288 bytes, i.e. the size of the test image dev$ypix, as the
+default image i/o buffer is exactly that size. However if the size of dev$ypix
+is doubled by converting it to a real image with the chpixtype task then the
+effect of cacheing in interactive is can be quite noticeable if measurements
+of objects in the top and bottom halfs of the image are alternated.
+
+FITSKY can be run either interactively or in batch mode by setting the parameter
+\fIinteractive\fR. In interactive mode the user may either define the
+list of objects to be measured interactively with the image cursor or
+create an object list prior to running  FITSKY. In either case the user may
+adjust the sky fitting parameters until a satisfactory measurement is achieved.
+coordinate list with that set of parameters. In batch mode 
+positions are read from the text file \fIcoords\fR or the image cursor
+parameter \fIicommands\fR can be redirected to a cursor command file.
+
+.ih
+CURSOR COMMANDS
+
+The following cursor commands are currently available.
+
+.nf
+	Interactive Keystroke Commands
+
+?	Print help
+:	Colon commands
+v	Verify the critical parameters
+w	Save the current parameters
+d	Plot radial profile of current star 
+i	Interactively set parameters using current star
+f	Fit sky for current star
+spbar	Fit sky for current star, output results
+m	Move to next star in coordinate list
+m	Fit sky for next star in coordinate list, output results
+l	Fit sky for remaining stars in coordinate list, output results
+e	Print error messages
+r	Rewind the coordinate list
+q	Exit task
+
+
+        Colon commands
+
+:show	[data/sky]	List the parameters
+:m [n]	Move to the next [nth] star in coordinate list
+:n [n]	Fit sky to next [nth] star in coordinate list, output results
+
+	Colon Parameter Editing Commands
+
+# Image and file name parameters
+
+:image		[string]	Image name
+:coords		[string]	Coordinate file name
+:output 	[string]	Output file name
+
+# Data dependent parameters
+
+:scale		[value]		Image scale (units per pixel)
+:fwhmpsf	[value]		Full width half maximum PSF (scale units)
+:emission	[y/n]		Emission feature (y), absorption (n)
+:sigma		[value]		Standard deviation of sky (counts)
+:datamin	[value]		Minimum good pixel value (counts)
+:datamax	[value]		Maximum good pixel value (counts)
+
+# Noise parameters
+
+:noise		[string]	Noise model (constant|poisson)
+:gain		[string]	Gain image header keyword
+:ccdread	[string]	Readout noise image header keyword
+:epadu		[value]		Gain (electrons per adu)
+:readnoise	[value]		Readout noise (electrons)
+
+# Observations parameters
+
+:exposure	[string]	Exposure time image header keyword
+:airmass	[string]	Airmass image header keyword
+:filter		[string]	Filter image header keyword
+:obstime	[string]	Time of observation image header keyword
+:itime		[value]		Exposure time (time units)
+:xairmass	[value]		Airmass value (number)
+:ifilter	[string]	Filter id string
+:otime		[string]	Time of observation (time units)
+
+# Sky fitting algorithm parameters
+
+:salgorithm	[string]	Sky fitting algorithm 
+:skyvalue	[value]		User supplied sky value (counts)
+:annulus 	[value]		Inner radius of sky annulus (scale units)
+:dannulus	[value]		Width of sky annulus (scale units)
+:khist		[value]		Sky histogram extent (+/- sky sigma)
+:smooth		[y/n]		Lucy smooth the sky histogram 
+:binsize	[value]		Resolution of sky histogram (sky sigma)
+:smaxiter	[value]		Maximum number of iterations
+:sloclip	[value]		Low side clipping factor (percent)
+:shiclip	[value]		High side clipping factor (percent)
+:snreject	[value]		Maximum number of rejection cycles
+:sloreject	[value]		Low side pixel rejection limits (sky sigma)
+:shireject	[value]		High side pixel rejection limits (sky sigma)
+:rgrow		[value]		Region growing radius (scale units)
+
+# Marking and plotting parameters
+
+:mksky		[y/n]		Mark sky annuli on the display
+:radplot	[y/n]		Plot radial profile of sky pixels
+
+
+The following commands are available from within the interactive setup menu.
+
+
+                      Interactive Fitsky Setup Menu
+
+	v	Mark and verify the critical parameters (a,d,s)
+
+	s	Mark and verify the standard deviation of the sky
+	l	Mark and verify the minimum good data value
+	u	Mark and verify the maximum good data value
+
+	a	Mark and verify the inner radius of the sky annulus
+	d	Mark and verify the width of the sky annulus
+	g	Mark and verify the region growing radius
+.fi
+
+.ih
+ALGORITHMS
+A brief description of the data dependent parameters and the sky fitting
+parameters can be found in the online manual pages for the DATAPARS
+and FITSKYPARS tasks.
+
+.ih
+OUTPUT
+In interactive mode the following quantities are printed on the standard
+output as each object is measured.
+
+.nf
+    image  xinit  yinit  msky  stdev  sskew  nsky  nsrej  error
+.fi
+
+In both interactive and batch mode full output is written to the 
+text file \fIoutput\fR. At the beginning of each file is a header listing
+the current values of the parameters when the first stellar record was
+written. These parameters can be subsequently altered. For each star
+measured the following record is written.
+
+.nf
+    image  xinit  yinit  id  coords  lid
+	msky  stdev  sskew  nsky  nsrej  sier  error
+.fi
+
+Image and coords are the name of the image and coordinate file respectively.
+Id and lid are the sequence numbers of stars in the output and coordinate
+files respectively. Sier and error are the error code and accompanying
+error message respectively. Xinit and yinit are the center coordinates
+of the sky annulus in pixels. Msky, stdev and sskew are the sky value,
+standard deviation and skew respectively. Nsky and nsrej are the number of
+sky pixels used and the number of sky pixels rejected respectively.
+
+In interactive mode a radial profile of each measured object is plotted
+in the graphics window if \fIradplots\fR is "yes".
+
+In interactive and batch mode a radial profile plot is written to
+\fIplotfile\fR  if it is defined each time the result of an object
+measurement is written to \fIoutput\fR .
+
+.ih
+ERRORS
+If all goes well during the sky fitting process then the error code sier
+will be 0. Non-zero values of sier flag the following error conditions.
+
+.nf
+	0         # No error
+	201       # There are no sky pixels in the sky annulus
+	202       # Sky annulus is partially off the image
+	203       # The histogram of sky pixels has no width
+	204       # The histogram of sky pixels is flat or concave
+	205       # There are too few points for a good sky fit
+	206       # The sky fit is singular
+	207       # The sky fit did not converge
+	208       # The graphics stream is undefined
+	209       # The file of sky values does not exist
+	210       # The sky file is at EOF
+	211       # Cannot read the sky value correctly
+	212       # The best fit parameters are non-physical
+.fi
+
+.ih
+EXAMPLES
+
+1. Compute the sky values for a few  stars in dev$ypix using the display
+and the image cursor. Setup the task parameters using the interactive
+setup menu defined by the i key command and a radial profile plot.
+
+.nf
+        ap> display dev$ypix 1 fi+
+
+        ... display the image
+
+        ap> fitsky dev$ypix
+
+        ... type ? to print an optional help page
+
+        ... move the image cursor to a star
+        ... type i to enter the interactive setup menu
+        ... enter maximum radius in pixels of the radial profile or hit
+            CR to accept the default
+        ... set the inner and outer sky annuli, and sigma  using the
+            graphics cursor and the stellar radial profile plot
+        ... typing <CR> leaves everything at the default value
+        ... type q to quit the setup menu
+
+        ... type the v key to verify the parameters
+
+        ... type the w key to save the parameters in the parameter files
+
+        ... move the image cursor to the stars of interest and tap
+            the space bar
+
+        ... a one line summary of the fitted parameters will appear on the
+            standard output for each star measured
+
+        ... type q to quit and q again to confirm the quit
+
+        ... the output will appear in ypix.sky.1
+.fi
+
+2. Compute the sky values for a few stars in dev$ypix using a contour plot
+and the graphics cursor. This option is only useful for those (now very few)
+users who have access to a graphics terminal but not to an image display
+server. Setup the task parameters using the interactive setup menu defined by
+the i key command as in example 1.
+
+.nf
+        ap> show stdimcur
+
+        ... record the default value of stdimcur
+
+        ap> set stdimcur = stdgraph
+
+        ... define the image cursor to be the graphics cursor
+
+        ap> contour dev$ypix
+
+        ... make a contour plot of dev$ypix
+
+        ap> contour dev$ypix >G ypix.plot1
+
+        ... store the contour plot of dev$ypix in the file ypix.plot1
+
+        ap> fitsky dev$ypix display=stdgraph
+
+        ... type ? to get an optional help page
+
+        ... move graphics cursor to a star
+        ... type i to enter the interactive setup menu
+        ... enter maximum radius in pixels of the radial profile or CR
+            to accept the default value
+        ... set the inner and outer sky annuli, and sigma using the
+            graphics cursor and the stellar radial profile plot
+        ... typing <CR> leaves everything at the default value
+        ... type q to quit the setup menu
+
+        ... type the v key to verify the critical parameters
+
+        ... type the w key to save the parameters in the parameter files
+
+        ... retype :.read ypix.plot1 to reload the contour plot
+
+        ... move the graphics cursor to the stars of interest and tap
+            the space bar
+
+        ... a one line summary of the fitted parameters will appear on the
+            standard output for each star measured
+
+        ... type q to quit and q again to verify
+
+        ... full output will appear in the text file ypix.sky.2
+
+        ap> set stdimcur = <default>
+
+        ... reset stdimcur to its previous value
+.fi
+
+3. Setup and run FITSKY interactively on a list of objects temporarily
+overriding the fwhmpsf, sigma, annulus, and dannulus parameters determined
+in examples 1 or 2.
+
+.nf
+        ap> daofind dev$ypix fwhmpsf=2.6 sigma=25.0 verify-
+
+        ... make a coordinate list
+
+        ... the output will appear in the text file ypix.coo.1
+
+        ap> fitsky dev$ypix annulus=12.0 dannulus=5.0 coords=ypix.coo.1
+
+        ... type ? for optional help
+
+
+        ... move the graphics cursor to the stars and tap space bar
+
+                                or
+
+        ... select stars from the input coordinate list with m / :m #
+            and measure with spbar
+
+        ... measure stars selected from the input coordinate list
+            with n / n #
+
+        ... a one line summary of results will appear on the standard output
+            for each star measured
+
+        ... type q to quit and q again to confirm the quit
+
+        ... the output will appear in ypix.sky.3 ...
+.fi
+
+
+4. Display and measure some stars in an image section and write the output
+coordinates in the coordinate system of the parent image.
+
+.nf
+        ap> display dev$ypix[150:450,150:450] 1
+
+        ... display the image section
+
+        ap> fitsky dev$ypix[150:450,150:450] wcsout=tv
+
+        ... move cursor to stars and type spbar
+
+        ... type q to quit and q again to confirm quit
+
+        ... output will appear in ypix.sky.4
+
+        ap> pdump ypix.sky.4 xi,yi yes | tvmark 1 STDIN col=204
+.fi
+
+5. Run FITSKY in batch mode using the coordinate file and the previously
+saved parameters. Verify the critical parameters.
+
+.nf
+        ap> fitsky dev$ypix coords=ypix.coo.1 verify+ inter-
+
+        ... output will appear in ypix.sky.5 ...
+.fi
+
+6. Repeat example 5 but assume that the input coordinate are ra and dec
+in degrees and degrees, turn off verification, and submit the task to to
+the background.
+
+.nf
+        ap> display dev$ypix 1
+
+        ap> rimcursor wcs=world > radec.coo
+
+        ... move to selected stars and type any key
+
+        ... type ^Z to quit
+
+        ap> fitsky dev$ypix coords=radec.coo wcsin=world verify- inter- &
+
+        ... output will appear in ypix.sky.6
+
+        ap> pdump ypix.sky.6 xi,yi yes | tvmark 1 STDIN col=204
+
+        ... mark the stars on the display
+.fi
+
+7. Run FITSKY interactively without using the image display.
+
+.nf
+        ap> show stdimcur
+
+        ... record the default value of stdimcur
+
+        ap> set stdimcur = text
+
+        ... set the image cursor to the standard input
+
+        ap> fitsky dev$ypix coords=ypix.coo.1
+
+        ... type ? for optional help
+
+        ... type :m 3 to set the initial coordinates to those of the
+            third star in the list
+
+        ... type i to enter the interactive setup menu
+        ... enter the maximum radius in pixels for the radial profile or
+            accept the default with a CR
+        ... type v to enter the default menu
+        ... set the inner and outer sky annuli, and sigma using the
+            graphics cursor and the stellar radial profile plot
+        ... typing <CR> after the prompt leaves the parameter at its default
+            value
+        ... type q to quit the setup menu
+
+        ... type r to rewind the coordinate list
+
+        ... type l to measure all the stars in the coordinate list
+
+        ... a one line summary of the answers will appear on the standard
+            output for each star measured
+
+        ... type q to quit followed by q to confirm the quit
+
+        ... full output will appear in the text file ypix.sky.7
+
+        ap> set stdimcur = <default>
+
+        ... reset the value of stdimcur
+.fi
+
+8. Use an image cursor command file to drive the FITSKY task. The cursor command
+file shown below sets the annulus and dannulus parameters, computes the sky
+values for 3 stars, updates the parameter files, and quits the task.
+
+.nf
+        ap> type cmdfile
+        : annulus 12.0
+        : dannulus 5.0
+        442 410 101 \040
+        349 188 101 \040
+        225 131 101 \040
+        w
+        q
+
+        ap> fitsky dev$ypix icommands=cmdfile verify-
+
+        ... full output will appear in ypix.sky.8
+.fi
+
+.ih
+TIME REQUIREMENTS
+
+.ih
+BUGS
+It is currently the responsibility of the user to make sure that the
+image displayed in the frame is the same as that specified by the image
+parameter.
+
+Commands which draw to the image display are disabled by default.
+To enable graphics overlay on the image display, set the display
+parameter to "imdr", "imdg", "imdb", or "imdy" to get red, green,
+blue or yellow overlays and set the fitskypars mksky switch to"yes".
+It may be necessary to run gflush and to redisplay the image
+to get the overlays position correctly.
+
+.ih
+SEE ALSO
+datapars, fitskypars, phot, polyphot, radprof
+.endhelp
diff --git a/noao/digiphot/apphot/doc/fitskypars.hlp b/noao/digiphot/apphot/doc/fitskypars.hlp
new file mode 100644
index 00000000..cdb541ba
--- /dev/null
+++ b/noao/digiphot/apphot/doc/fitskypars.hlp
@@ -0,0 +1,219 @@
+.help fitskypars May00 noao.digiphot.apphot
+.ih
+NAME
+fitskypars - edit the sky fitting algorithm parameters
+.ih
+USAGE
+fitskypars
+.ih
+PARAMETERS
+.ls salgorithm = "centroid"
+The sky fitting algorithm to be employed. The sky fitting options are:
+.ls constant
+Use a user supplied constant value \fIskyvalue\fR for the sky.
+This algorithm is useful for measuring large resolved objects on flat
+backgrounds such as galaxies or comments.
+.le
+.ls file
+Read sky values from a text file. This option is useful for importing
+user determined sky values into APPHOT.
+.le
+.ls mean
+Compute the mean of the sky pixel distribution. This algorithm is useful
+for computing sky values in regions with few background counts.
+.le
+.ls median
+Compute the median of the sky pixel distribution. This algorithm is a useful
+for computing sky values in regions with rapidly varying sky backgrounds
+and is a good alternative to "centroid".
+.le
+.ls mode
+Compute the mode of the sky pixel distribution using the computed mean and
+median.  This is the recommended algorithm for APPHOT users trying to
+measuring stellar objects in crowded stellar fields. Mode may not perform
+well in regions with rapidly varying sky backgrounds.
+.le
+.ls centroid
+Compute the intensity-weighted mean or centroid of the sky pixel histogram.
+This is the algorithm recommended for most APPHOT users. It is reasonably
+robust in rapidly varying and crowded regions.
+.le
+.ls gauss
+Fit a single Gaussian function to the sky pixel histogram using non-linear
+least-squares techniques.
+.le
+.ls ofilter
+Compute the sky using the optimal filtering algorithm and a triangular
+weighting function and the histogram of the sky pixels.
+.le
+.ls crosscor
+Compute the sky value using the cross-correlation function of the sky pixel
+histogram and a Gaussian noise function with a sigma equal to the
+computed sigma of the sky pixel distribution.
+.le
+.ls histplot
+Mark the peak of the histogram of the sky pixels on a plot of the histogram.
+This algorithm is useful for making careful interactive sky measurements
+for a small number of objects in complicated regions or for checking the
+behavior of other sky algorithms.
+.le
+.ls radplot
+Mark the sky value on a radial distribution plot of the sky pixels.
+This algorithm is useful for making careful interactive sky measurements
+for a small number of objects in complicated regions or for checking the
+behavior of other sky algorithms.
+.le
+.le
+.ls annulus = 10.0  (scale units)
+The inner radius of the annular sky fitting region in units of the DATAPARS
+scale parameter.
+.le
+.ls dannulus = 10.0  (scale units)
+The width of the annular sky fitting region in units of the DATAPARS
+scale parameter.
+.le
+.ls skyvalue
+The constant for constant sky subtraction.
+.le
+.ls smaxiter = 10
+The maximum number of iterations performed by the sky fitting algorithm.
+\fISmaxiter\fR is required by the "gauss" and "ofilter" sky fitting algorithms.
+.le
+.ls sloclip = 0.0 (percent)
+The low-side clipping factor in percentage points of the total number of
+sky pixels.
+.le
+.ls shiclip = 0.0 (percent)
+The high-side clipping factor in percentage points of the total number of
+sky pixels.
+.le
+.ls snreject = 50
+The maximum number of pixel rejection cycles.
+.le
+.ls sloject = 3.0
+The ksigma low-side clipping factor for the pixel rejection  phase of the
+sky fitting algorithm. \fIsloreject\fR is in units of the computed sky
+sigma.
+.le
+.ls shiject = 3.0
+The ksigma high-side clipping factor for the pixel rejection  phase of the
+sky fitting algorithm. \fIshireject\fR is in units of the computed sky
+sigma.
+.le
+.ls khist = 3.0 
+The ksigma clipping factor for computing the histogram of the sky pixels.
+\fIKhist\fR is in units of the computed sky sigma.
+The computed histogram will be 2.0 * khist * sigma wide.
+.le
+.ls binsize = 0.10
+The width of a single bin of the histogram of sky values.
+\fIBinsize\fR is in units of the computed sky sigma.
+.le
+.ls smooth = no
+Boxcar smooth the histogram before computing a sky value ?
+.le
+.ls rgrow = 0.0  (scale units)
+The region growing radius for pixel rejection in the sky region, in units
+of the DATAPARS \fIscale\fR parameter. When a bad sky pixel is detected,
+all pixels within rgrow / scale will be rejected. If rgrow is 0.0
+region growing is not performed.
+.le
+.ls mksky = no
+Mark the sky annulus on the displayed image ? 
+.le
+.ih
+DESCRIPTION
+The sky fitting algorithm parameters control the action of the sky fitting
+algorithms. The default parameter settings should give reasonable results in
+the majority of cases.  Several of the sky fitting parameters scale with
+image scale, \fIscale\fR which is data dependent. \fIScale\fR is defined in
+the DATAPARS parameter set.
+
+Sky pixels in an annular region of inner radius \fIannulus / scale\fR pixels
+and a width of \fIdannulus / scale\fR pixels are extracted from the IRAF image.
+If the \fIscale\fR parameter is defined in terms of the number of half-width
+at half-maximum of the point spread function per pixel, then single values of
+annulus and dannulus will work well for images with different seeing and
+detector characteristics.
+
+Pixels outside of the good data range specified by \fIdatamin\fR and
+\fIdatamax\fR are rejected from the sky pixel distribution. After bad
+data rejection \fIPloclip\fR and \fIphiclip\fR percent pixels are rejected
+from the low and high sides of the sorted pixel distribution before any
+sky fitting is done.
+
+Sky values are computed using the sky fitting algorithm specified by
+\fIsalgorithm\fR. The default value is "centroid". If \fIsalgorithm\fR
+= "mean", "median" or "mode", the sky value is computed directly from the
+array of sky pixels.  The remaining sky fitting algorithms use the histogram
+of the object sky pixels. The computed histogram is \fIkhist\fR * sigma wide
+with a bin width of \fIbinsize\fR * sigma  where sigma is the computed
+standard deviation of the sky pixels for each object. If \fIsmooth\fR = yes,
+boxcar smoothing is performed on the computed histogram before sky fitting.
+The mode of the histogram is  computed using, a non-linear least squares
+fit to a Gaussian (salgorithm = "gauss"), optimal filtering of the histogram
+(salgorithm = "ofilter"), computing the intensity weighted mean of the
+histogram (salgorithm = "centroid"), or by cross-correlation techniques 
+(salgorithm = "crosscor").
+
+Two interactive methods of fitting sky are also available. If \fIsalgorithm\fR
+is "radplot" or "histplot", the user must interactively set the value of the
+sky using a radial profile or a histogram profile plot.
+
+Pixels which deviate from the sky value by more than \fIkreject\fR times the
+computed sky sigma are rejected from the fit. If \fIrgrow\fR > 0, pixels
+within a radius of rgrow / scale of the rejected pixel are also rejected from
+the fit. The rejection procedure iterates until no further pixels are rejected,
+all pixels are rejected, or the maximum number of rejection cycles
+\fIsnreject\fR iterations is reached.
+
+.ih
+EXAMPLES
+1. List the sky fitting parameters.
+
+.nf
+	ap> lpar fitskypars
+.fi
+
+2. Edit the sky fitting parameters.
+
+.nf
+	ap> fitskypars
+.fi
+
+3. Edit the FITSKYPARS parameters from within the PHOT task.
+
+.nf
+    da> epar phot
+
+	... edit a few phot parameters
+
+	... move to the fitskypars parameter and type :e
+
+	... edit the fitskypars parameters and type :wq
+
+	... finish editing the phot parameters and type :wq
+.fi
+
+4. Save the current FITSKYPARS parameter set in a text file skynite1.par.
+This can also be done from inside a higher level task as in the
+above example.
+
+.nf
+    da> fitskypars
+
+	... edit some parameters
+
+	... type ":w skynite1.par"  from within epar
+.fi
+
+.ih
+TIME REQUIREMENTS
+
+.ih
+BUGS
+
+.ih
+SEE ALSO
+radprof,fitsky,phot,wphot,polyphot
+.endhelp
diff --git a/noao/digiphot/apphot/doc/pexamine.hlp b/noao/digiphot/apphot/doc/pexamine.hlp
new file mode 100644
index 00000000..f3a031ec
--- /dev/null
+++ b/noao/digiphot/apphot/doc/pexamine.hlp
@@ -0,0 +1,836 @@
+.help pexamine May00 noao.digiphot.apphot
+.ih
+NAME
+pexamine -- interactively examine or edit a photometry catalog
+.ih
+USAGE
+pexamine input output image
+.ih
+PARAMETERS
+.ls input
+The name of the input photometry catalog. \fIInput\fR may be either an
+APPHOT/DAOPHOT text database file or an STSDAS binary table database.
+.le
+.ls output
+The name of the edited output catalog. \fIOutput\fR is either an
+APPHOT/DAOPHOT text database or an STSDAS binary table database
+depending on the file type of \fIinput\fR. If \fIoutput\fR = "" no output
+catalog is written.
+.le
+.ls image
+The name of the input image corresponding to the input photometry
+catalog. If \fIimage\fR is "" no image will be attached to PEXAMINE
+and some interactive catalog examining commands will not be available.
+All the catalog editing commands however are still available.
+.le
+.ls deletions = ""
+The name of an optional output deletions photometry catalog. \fIDeletions\fR
+is either an APPHOT/DAOPHOT text database or an STSDAS binary
+table database depending on the file type of \fIinput\fR. If \fIdeletions\fR
+is "" no deletions file is written.
+.le
+.ls photcolumns = "apphot"
+The list of standard photometry columns that are loaded when pexamine is
+run. The options are listed below.
+.ls "apphot"
+The standard columns for the APPHOT package. The current list is ID,
+XCENTER, YCENTER, MSKY, MAG, and MERR.
+If any of these
+columns are multi-valued, (as in the case of magnitudes measured through
+more than one aperture), the first value is selected.
+The standard list may easily be extended at user request.
+.le
+.ls "daophot"
+The standard columns for the DAOPHOT package. The current list is GROUP, ID,
+XCENTER, YCENTER, MSKY, MAG, MERR, CHI, SHARP and NITER.
+If any of these
+columns are multi-valued, (as in the case of magnitudes measured through
+more than one aperture), the first value is selected.
+The standard list may easily be extended at user request.
+.le
+.ls user list
+A user supplied list of standard columns.
+Column names are listed in full in either upper or
+lower case letters, separated by commas. If more than one value of
+a multi-valued column is requested
+the individual values 
+must be listed separately as in the following example
+ID, XCENTER, YCENTER, MAG[1], MERR[1], MAG[2], MERR[2].
+.le
+
+\fIPhotcolumns\fR can be changed interactively from within PEXAMINE at
+the cost of rereading the database. 
+.le
+.ls xcolumn = "mag" (magnitude), ycolumn = "merr" (magnitude error)
+The names of the two columns which define the default X-Y plot.
+\fIXcolumn\fR and \fIycolumn\fR must be listed in \fIphotcolumns\fR or
+\fIusercolumns\fR but may be changed interactively by the user.
+If either \fIxcolumn\fR or \fIycolumn\fR is a multi-valued quantity
+and more than one value is listed in \fIphotcolumns\fR or \fIusercolumns\fR
+then the desired value number must be specified explicitly in, e.g.
+MAG[2] or MERR[2].
+.le
+.ls hcolumn = "mag" (magnitude)
+The name of the column which defines the default histogram plot.
+\fIHcolumn\fR must be listed in \fIphotcolumns\fR or
+\fIusercolumns\fR but may be changed interactively by the user.
+If \fIhcolumn\fR is a multi-valued quantity and more than one value is
+listed in \fIphotcolumns\fR or \fIusercolumns\fR then the desired value
+must be specified explicitly in \fIhcolumn\fR, e.g. MAG[2].
+.le
+.ls xposcolumn = "xcenter", yposcolumn = "ycenter"
+The names of the two columns which define the X and Y coordinates in
+\fIimage\fR of the objects in the catalog. This information is
+required if the image display and image cursor are to be used to visually
+identify objects in the image with objects in the catalog or if plots
+of image data are requested. \fIXposcolumn\fR and \fIyposcolumn\fR must
+be listed in \fIphotcolumns\fR or \fIusercolumns\fR but may
+be changed interactively by the user.
+.le
+.ls usercolumns = ""
+The list of columns loaded into memory in addition to the
+standard photometry columns \fIphotcolumns\fR. The column
+names are listed in full in upper or lower case letters and separated by
+commas.
+\fIUsercolumns\fR can be changed interactively from within PEXAMINE at
+the cost of rereading the database. 
+.le
+.ls first_star = 1
+The index of the first object to be read out of the catalog.
+.le
+.ls max_nstars = 5000
+The maximum number of objects that are loaded into memory at task
+startup time, beginning at object \fIfirst_star\fR. If there are more
+than \fImax_nstars\fR in the catalog only the first \fImax_nstars\fR
+objects are read in.
+.le
+.ls match_radius = 2.0
+The tolerance in pixels to be used for matching objects in the catalog with
+objects marked on the display with the image cursor.
+.le
+.ls graphics = "stdgraph"
+The default graphics device.
+.le
+.ls use_display = yes
+Use the image display? Users without access to an image display should
+set \fIuse_display\fR to "no".
+.le
+.ls icommands = ""
+The image display cursor. If null the standard image cursor is used whenever
+image cursor input is requested. A cursor file in the appropriate
+format may be substituted by specifying the name of the file.
+Also the image cursor may be changed to query the graphics device or the
+terminal by setting the environment variable "stdimcur" to "stdgraph"
+or "text" respectively.
+.le
+.ls gcommands = ""
+The graphics cursor. If null the standard graphics cursor is used whenever
+graphics cursor input is requested. A cursor file in the appropriate
+format may be substituted by specifying the name of the file.
+.le
+
+.ih
+PLOTTING PARAMETERS
+
+PEXAMINE supports five types of plots 1) an X-Y column plot
+2) a histogram column plot 3) a radial profile plot 4) a surface
+plot and 5) a contour plot.
+Each supported plot type has its own parameter set which
+controls the appearance of the plot.
+The names of the five parameter sets are listed below.
+
+.nf
+    cntrplot	Parameters for the contour plot
+    histplot	Parameters for the column histogram plot
+    radplot	Parameters for radial profile plot
+    surfplot	Parameters for surface plot
+    xyplot	Parameters for the X-Y column plot	
+.fi
+
+The same  parameters dealing with graph formats occur in many of the parameter
+sets while some are specific only to one parameter set.  In the
+summary below those common to more than one parameter set are shown
+only once.  The characters in parenthesis are the graph key prefixes
+for the parameter sets in which the parameter occurs.
+
+.ls angh = -33., angv = 25.		(s)
+Horizontal and vertical viewing angles in degrees for surface plots.
+.le
+.ls axes = yes				(s)
+Draw axes along the edge of surface plots?
+.le
+.ls banner = yes 			 (chrsx)
+Add a standard banner to a graph?  The standard banner includes the
+IRAF user and host identification and the date and time.
+.le
+.ls box = yes 				(chrx)
+Draw graph box and axes?
+.le
+.ls ceiling = INDEF			(cs)
+Ceiling data value for contour and surface plots.  A value of INDEF does
+not apply a ceiling.  In contour plots a value of 0. also does not
+apply a ceiling.
+.le
+.ls dashpat = 528			(c)
+Dash pattern for negative contours.
+.le
+.ls fill = no (yes)			(c) (hrx)
+Fill the output viewport regardless of the device aspect ratio?
+.le
+.ls floor = INDEF			(cs)
+Floor data value for contour and surface plots.  A value of INDEF does
+not apply a floor.  In contour plots a value of 0. also does not
+apply a floor.
+.le
+.ls grid = no				(rx)
+Draw grid lines at major tick marks?
+.le
+.ls interval = 0.0			(c)
+Contour interval.  If 0.0, a contour interval is chosen which places 20 to 30
+contours spanning the intensity range of the image.
+.le
+.ls label= no				(c)
+Label the major contours in the contour plot?
+.le
+.ls logx = no, logy = no		(rx) (hrx)
+Plot the x or y axis logarithmically?  The default for histogram plots is
+to plot the y axis logarithmically.
+.le
+.ls majrx=5, minrx=5, majry=5, minry=5	(chrx)
+Maximum number of major tick marks on each axis and number of minor tick marks
+between major tick marks.
+.le
+.ls marker = "box"			(rx)
+Marker to be drawn.  Markers are "point", "box", 
+"cross", "plus", "circle", "hline", "vline" or "diamond".
+.le
+.ls nbins = 512				(h)
+The number of bins in, or resolution of, histogram plots.
+.le
+.ls ncolumns = 21, nlines = 21		(cs)
+Number of columns and lines used in contour and surface plots.
+.le
+.ls ncontours = 5			(c)
+Number of contours to be drawn.  If 0, the contour interval may be specified,
+otherwise 20 to 30 nicely spaced contours are drawn.  A maximum of 40 contours
+can be drawn.
+.le
+.ls nhi = -1				(c)
+If -1, highs and lows are not marked.  If 0, highs and lows are marked
+on the plot.  If 1, the intensity of each pixel is marked on the plot.
+.le
+.ls rinner = 0, router = 8
+The inner and outer radius of the region whose radial profile is to
+be plotted.
+.le
+.ls round = no				(chrx)
+Extend the axes up to "nice" values?
+.le
+.ls szmarker = 1			(rx)
+Size of mark except for points.  A positive size less than 1 specifies
+a fraction of the device size.  Values of 1, 2, 3, and 4 signify
+default sizes of increasing size.
+.le
+.ls ticklabels = yes			(chrx)
+Label the tick marks?
+.le
+.ls top_closed = no			(h)
+Include z2 in the top histogram bin?  Each bin of the histogram is a
+subinterval that is half open at the top.  \fITop_closed\fR decides whether
+those pixels with values equal to z2 are to be counted in the histogram.  If
+\fBtop_closed\fR is yes, the top bin will be larger than the other bins.
+.le
+.ls x1 = INDEF, x2 = INDEF, y1 = INDEF, y2 = INDEF	(hrx)
+Range of graph along each axis.  If INDEF the range is determined from
+the data range.  The default y1 for histogram plots is 0.
+.le
+.ls zero = 0.				(c)
+Greyscale value of the zero contour, i.e., the value of a zero point shift
+to be applied to the image data before plotting.  Does not affect the values
+of the floor and ceiling parameters.
+.le
+.ls z1 = INDEF, z2 = INDEF		(h)
+Range of pixel values to be used in histogram.  INDEF values default to
+the range in the region being histogramed.
+.le
+
+.ih
+DESCRIPTION
+
+PEXAMINE is a general purpose tool for interactively examining and editing
+photometry catalogs produced by the APPHOT or DAOPHOT packages. It is
+intended to aid the user in assessing the accuracy of the photometry,
+in diagnosing problems with particular catalog objects,
+in searching the photometry data for relationships
+between the computed quantities, and in editing the catalog based on
+those observed relationships. PEXAMINE is intended to complement the
+more batch oriented editing facilities of the SELECT task.
+
+PEXAMINE takes the input catalog \fIinput\fR and the corresponding
+image \fIimage\fR (if defined) and produces an output catalog of selected
+objects \fIoutput\fR (if defined) and an output catalog of deleted objects
+\fIdeletions\fR (if defined). The input catalog may be either an
+APPHOT/DAOPHOT text database or an ST binary table database.
+The file type of the output catalogs \fIoutput\fR and \fIdeletions\fR
+is the same as that of \fIinput\fR.
+
+READING IN THE DATA
+
+PEXAMINE reads the column data specified by \fIphotcolumns\fR and
+\fIusercolumns\fR for up to \fImax_nstars\fR beginning at star
+\fIfirst_star\fR into memory.
+The \fIphotcolumns\fR parameter
+defines the list of standard photometry columns to be loaded. If
+"daophot" or "apphot" is selected then the standard columns
+are GROUP, ID, XCENTER, YCENTER, MSKY, MAG, MERR, CHI, SHARP and NITER
+and ID, XCENTER, YCENTER, MSKY, MAG and MERR respectively.
+Otherwise the user must set \fIphotcolumns\fR to his or her own preferred
+list of standard photometry columns. Non-standard columns may also be
+specified using the parameter \fIusercolumns\fR.
+Valid column lists contain the full names of the specified columns
+in upper or lower case letters, separated by commas.
+Either \fIphotcolumns\fR or 
+\fIusercolumns\fR may be redefined interactively by the user after
+the task has started up, but only at the
+expense of rereading the data from \fIinput\fR.
+
+PEXAMINE will fail to load a specified column if that column is
+not in the photometry database, is of a datatype other than
+integer or real, or adding that column would exceed the maximum
+number of columns limit currently set at twenty. The user can
+interactively examine the list of requested and loaded standard
+photometry columns, as well as list all the columns in the input
+after the task has started up.
+
+GRAPHICS AND IMAGE COMMAND MODE
+
+PEXAMINE accepts commands either from the graphics cursor \fIgcommands\fR
+(graphics command mode) or the image display cursor \fIicommands\fR
+if available (image command mode).
+PEXAMINE starts up in graphics command mode, but all the
+interactive commands are accessible from both modes and the user can
+switch modes at any time assuming that the \fIuse_display\fR parameter
+is set to "yes".
+
+PEXAMINE interprets the cursor position in graphics command mode
+differently from how it interprets it in image command mode.
+In graphics command mode the cursor coordinates are the position
+of the cursor in the current plot, whereas in image command mode they
+are the x and y coordinates of the cursor in the displayed image.
+For example, if the user issues a command to PEXAMINE to locate the object
+in the catalog nearest the point in the current X-Y plot marked by
+the graphics cursor, PEXAMINE does so by searching
+the data for the object whose values of \fIxcolumn\fR and \fIycolumn\fR
+most closely match those of the current cursor position.
+If the user issues a command  to PEXAMINE to locate the
+object in the catalog corresponding to the object marked on the image
+display with the image cursor,
+PEXAMINE does so by searching the data for
+the object whose values of \fIxposcolumn\fR and \fIyposcoumn\fR
+most closely match and fall within \fImatch_radius\fR of the current
+cursor position.
+
+Input to PEXAMINE is through single keystroke commands or colon
+commands. Keystroke commands are simple commands that may
+optionally use the cursor position but otherwise require no arguments.
+The PEXAMINE keystroke commands fall into three categories, basic
+commands, data examining commands and data editing commands, all
+described in detail in the following sections. Colon commands
+take an optional argument and function differently depending on
+the presence or absence of that argument. When the argument is absent
+colon commands are used to display the
+current value of a parameter or list of parameters. When the argument is
+present they change their current value to that argument.
+The basic colon commands are described in detail below. 
+
+BASIC KEYSTROKE COMMANDS
+
+These keystroke commands are used to display the help page, switch from
+graphics to image command mode and quit the task.
+
+.ls ?
+Page through the help for the PEXAMINE task
+.le
+.ls :
+Execute a PEXAMINE colon command.
+.le
+.ls g
+Change to graphics command mode. Throughout PEXAMINE graphics command mode
+is the default. All PEXAMINE commands are available in graphics command
+mode.
+.le
+.ls i
+Change to image command mode.
+All the PEXAMINE commands are available in image command mode.
+However if \fIuse_display\fR is no and the image
+cursor has not been aliased to the standard input or a text file
+image command mode is disabled.
+.le
+.ls q
+Quit PEXAMINE without writing an output catalog.
+PEXAMINE queries the user for confirmation of this option.
+.le
+.ls e
+Quit PEXAMINE and write the output catalog.
+.le
+
+DATA EXAMINING COMMANDS
+
+The data examining commands fall into two categories, those that examine
+the catalog data including 'l' (catalog listing), 'o' (object listing),
+'x' (Y column versus X column plot) and 'h' (histogram column plot)
+commands, and those which examine the image data around specific catalog
+objects including 'r' (radial profile plotting), 's' (surface plotting),
+'c' (contour plotting) and 'm' (pixel dumping). The latter group
+require that \fIimage\fR be defined. A brief summary of each data
+examining command is given below.
+.ls l
+Print out the name, datatype, and units for all the columns in the input
+catalog. The list command can be used to check the contents of the input
+catalog and/or determine why a particualar column was not loaded.
+.le
+.ls o
+Print out the names and values of the stored columns of the object
+nearest the cursor. In graphics mode the current plot type must be
+X-Y. In image command mode the object nearest the cursor must also be
+no more than \fImatch-radius\fR pixels away from the image cursor to be
+found. If an object is found and the current plot type is X-Y
+the graphics cursor is moved to the position of the selected object
+in the X-Y plot.
+.le
+.ls x
+Plot the data in \fIycolumn\fR versus the data in \fIxcolumn\fR excluding
+any already deleted points and identifying objects marked for deletion
+with a cross. X-Y plotting is undefined if \fIxcolumn\fR or \fIycolumn\fR
+is undefined.
+.le
+.ls h
+Plot the histogram of the data in \fIhcolumn\fR excluding any already 
+deleted points and those marked for deletion. Histogram plotting is
+disabled if \fIhcolumn\fR is undefined.
+.le
+.ls r
+Plot the radial profile of the object nearest the cursor including
+only pixels within a distance of \fIrinner\fR and \fRrouter\R of
+the object center. Radial profile plotting is disabled if \fIimage\fR
+or \fIxposcolumn\fR or \fIyposcolumn\fR is undefined.
+.le
+.ls s
+Plot the surface plot of the object nearest the cursor including
+only pixels within an image section \fIncols\fR by \fInlines\fR
+around the object center. Surface plotting is disabled if \fIimage\fR
+or \fIxposcolumn\fR or \fIyposcolumn\fR is undefined.
+.le
+.ls c
+Plot the contour plot of the object nearest the cursor including
+only pixels within an image section \fIncols\fR by \fInlines\fR
+around the object center. Contour plotting is disabled if \fIimage\fR
+or \fIxposcolumn\fR or \fIyposcolumn\fR is undefined.
+.le
+.ls m
+Dump the pixel values of a grid of 10 by 10 pixels around the object
+nearest the cursor. Pixel value dumping is disabled if \fIimage\fR
+or \fIxposcolumn\fR or \fIyposcolumn\fR is undefined.
+.le
+.ls p
+Replot the current graph.
+.le
+
+DATA EDITING COMMANDS
+
+Data points can be deleted from the catalog in either graphics command
+mode or image
+command mode. In graphics command mode the 
+graphics cursor and either the X-Y or histogram plot is used to delete points.
+In image command mode the image cursor and the displayed
+image are used to delete points. A data point has three possible states
+good, marked for deletion and deleted.
+Any one of the keystroke commands 'd' (delete point), '(' (delete points
+with x less than x cursor), ')' (delete points with x greater than x cursor,
+'^' (delete points with y > y cursor), 'v' (delete points with y < y cursor)
+or 'b' (delete points in a box) can be used to mark points for deletion.
+The 'f' key is used to actually delete the points and replot the data.
+In between marking the points for deletion and actually deleting the marked
+points the 't' (toggle) key can be used to undelete the last set marked.
+The full list of the data editing keystroke commands is given below.
+
+.ls z
+Undelete not just unmark all the data points replot.
+.le
+.ls f
+Delete points marked for deletion and replot. Points marked for deletion
+but not actually deleted will be written to the output catalog and not
+written to the deletions catalog.
+.le
+.ls d
+Mark the point nearest the cursor for deletion.
+.le
+.ls u
+Undelete the marked point nearest the cursor.
+.le
+.ls (
+Mark all points with x values less than the x value of the cursor for
+deletion.  In graphics command mode points can only be marked for deletion if
+the current plot type is "xyplot" or "histplot". In image command
+mode \fIxposcolumn\fR and \fIyposcolumn\fR must be defined before
+points can be marked for deletion.
+.le
+.ls )
+Mark all points with x values greater than the x value of the cursor for
+deletion.  In graphics command mode points can only be marked for deletion if
+the current plot type is "xyplot" or "histplot". In image command
+mode \fIxposcolumn\fR and \fIyposcolumn\fR must be defined before
+points can be marked for deletion.
+.le
+.ls v
+Mark all points with y values less than the y value of the cursor for
+deletion.  In graphics command mode points can only be marked for deletion if
+the current plot type is "xyplot". In image command
+mode \fIxposcolumn\fR and \fIyposcolumn\fR must be defined before
+points can be marked for deletion.
+.le
+.ls ^
+Mark all points with y values greater than the y value of the cursor for
+deletion.  In graphics command mode points can only be marked for deletion if
+the current plot type is "xyplot". In image command
+mode \fIxposcolumn\fR and \fIyposcolumn\fR must be defined before
+points can be marked for deletion.
+.le
+.ls b
+Mark all points within a box whose lower left and upper right hand corners
+are marked by the cursor for deletion.
+In graphics mode points can only be marked for deletion if the current
+plot type is "xyplot". In image command mode \fIxposcolumn\fR and
+\fIyposcolumn\fR must be defined before points can be marked for
+deletion.
+.le
+.ls t
+Toggle between marking points for deletion or undeletion. The default
+is to mark points for deletion.
+.le
+
+BASIC COLON COMMANDS
+
+All the PEXAMINE parameters can be changed interactively with colon
+commands, including those which determine which data is read in,
+which data is plotted and the parameters of each plot. A brief description
+of the basic commands is given here. The full list is given in the
+following section.
+
+.ls :photcolumns [col1,col2,...]
+Show or set the list of requested standard photometry columns and the list
+of loaded
+photometry columns. If the user supplies a new list of columns the data will be
+reread from disk.
+.le
+.ls :usercolumns [col1,col2,...]
+Show or set the list of requested user columns and the list of loaded
+user columns. If the user supplies a new list of columns the data will be
+reread from disk.
+.le
+.ls :xcolumn [colname]
+Show or set the name of the column to be plotted along the x axis of the
+X-Y plot.
+.le
+.ls :ycolumn [colname]
+Show or set the name of the column to be plotted along the y axis of the
+X-Y plot.
+.le
+.ls :hcolumn [colname]
+Show or set the name of the column to be whose histogram is to be plotted.
+.le
+.ls :eparam [cntrplot/histplot/radplot/surfplot/xyplot]
+Review or edit the list of parameters for the various plot types.
+.le
+.ls :unlearn [cntrplot/histplot/radplot/surfplot/xyplot]
+Return the list of parameters for the various plot types to their default
+values.
+.le
+.ls :x y key cmd
+Execute any defined keystroke "key" supplying the appropriate x and y
+value in place of the cursor position. In graphics command mode the x
+and y position are assumed to be the position in the current graph.
+In image command mode the x and y position are assumed to be the x and
+y coordinate in the image display.
+.le
+
+.ih
+CURSOR COMMANDS
+
+.nf
+	PEXAMINE Interactive Cursor Keystroke Commands
+
+                   Basic Commands
+
+?	Print help for the PEXAMINE task
+:	PEXAMINE colon commands
+g	Activate the graphics cursor
+i	Activate the image cursor
+e	Exit PEXAMINE and save the edited catalog
+q	Quit PEXAMINE and discard the edited catalog
+
+		   Data Examining Commands
+
+l	List the name, datatype and units for all columns in the catalog 	
+o	Print out the names and values of the stored columns for the
+	    object nearest the cursor
+x	Replot the current y column versus the current x column
+h	Replot the current histogram
+r	Plot the radial profile of the object nearest the cursor
+s	Plot the surface of the object nearest the cursor
+c	Plot the contour plot of the object nearest the cursor
+m	Print the data values of the object nearest the cursor
+p	Replot the current graph
+
+                   Data Editing Commands
+
+z	Reinitialize the data by removing all deletions and replot
+d	Mark the point nearest the cursor for deletion
+u	Undelete the marked point nearest the cursor
+t	Toggle between marking points for deletion or undeletion
+(	Mark points with X < X (cursor) for deletion or undeletion
+)	Mark points with X > X (cursor) for deletion or undeletion
+v	Mark points with Y < Y (cursor) for deletion or undeletion
+^	Mark points with Y > Y (cursor) for deletion or undeletion
+b	Mark points inside a box for deletion or undeletion
+f	Actually delete the marked points and replot
+
+
+	      PEXAMINE Interactive Colon Commands
+
+:xcolumn	  [name]	     Show/set the X-Y plot X axis quantity
+:ycolumn	  [name]	     Show/set the X-Y plot Y axis quantity
+:hcolumn	  [name]	     Show/set the histogram plot quantity  
+:photcolumns	  [col1,col2,...]    Show/set the list of photometry columns
+:usercolumns	  [col1,col2,...]    Show/set the list of user columns
+:delete		  [yes/no]	     Delete or undelete points
+:eparam		  [x/h/r/s/c]	     Edit/unlearn the specified plot pset
+    or
+:unlearn
+
+
+	     PEXAMINE Interactive X-Y Plotting Commands
+
+:x1	    [value]	  Left  world x-coord if not autoscaling
+:x2 	    [value]	  Right world x-coord if not autoscaling
+:y1         [value]	  Lower world y-coord if not autoscaling
+:y2         [value]	  Upper world y-coord if not autoscaling
+:szmarker   [value]	  Marker size
+:marker [point|box|plus|cross|circle|diamond|hline|vline]    Marker type
+:logx       [yes/no]	  Log scale the x axis?
+:logy       [yes/no]      Log scale the y axis?
+:box        [yes/no]      Draw box around periphery of window?
+:ticklabels [yes/no]	  Label tick marks?
+:grid       [yes/no]	  Draw grid lines at major tick marks? 
+:majrx      [value]	  Number of major divisions along x axis
+:minrx      [value]	  Number of minor divisions along x axis
+:majry      [value]	  Number of major divisions along y axis
+:minry      [value]	  Number of minor divisions along y axis
+:round      [yes/no]      Round axes to nice values?
+:fill       [yes/no]      Fill viewport vs enforce unity aspect ratio?
+
+
+	PEXAMINE Interactive Histogram Plotting Commands
+
+:nbins	    [value]	  Number of bins in the histogram
+:z1	    [value]	  Minimum histogram intensity
+:z2	    [value]	  Maximum histogram intensity
+:top_closed [y/n]	  Include z in the top bin?
+:x1	    [value]	  Left  world x-coord if not autoscaling
+:x2	    [value]	  Right world x-coord if not autoscaling
+:y1         [value]	  Lower world y-coord if not autoscaling
+:y2         [value]	  Upper world y-coord if not autoscaling
+:logy       [yes/no]      Log scale the y axis?
+:box        [yes/no]      Draw box around periphery of window?
+:ticklabels [yes/no]	  Label tick marks?
+:majrx      [value]	  Number of major divisions along x axis
+:minrx      [value]	  Number of minor divisions along x axis
+:majry      [value]	  Number of major divisions along y axis
+:minry      [value]	  Number of minor divisions along y axis
+:round      [yes/no]      Round axes to nice values?
+:fill       [yes/no]      Fill viewport vs enforce unity aspect ratio?
+
+	PEXAMINE Interactive Radial Profile Plotting Commands
+
+:rinner	    [value]	  Inner radius of the region to be plotted
+:router	    [value]	  Outer radius of the region to be plotted
+:x1	    [value]	  Left  world x-coord if not autoscaling
+:x2 	    [value]	  Right world x-coord if not autoscaling
+:y1         [value]	  Lower world y-coord if not autoscaling
+:y2         [value]	  Upper world y-coord if not autoscaling
+:szmarker   [value]	  Marker size
+:marker [point|box|plus|cross|circle|diamond|hline|vline]    Marker type
+:logx       [yes/no]	  Log scale the x axis?
+:logy       [yes/no]      Log scale the y axis?
+:box        [yes/no]      Draw box around periphery of window?
+:ticklabels [yes/no]	  Label tick marks?
+:grid       [yes/no]	  Draw grid lines at major tick marks? 
+:majrx      [value]	  Number of major divisions along x axis
+:minrx      [value]	  Number of minor divisions along x axis
+:majry      [value]	  Number of major divisions along y axis
+:minry      [value]	  Number of minor divisions along y axis
+:round      [yes/no]      Round axes to nice values?
+:fill       [yes/no]      Fill viewport vs enforce unity aspect ratio?
+
+
+	PEXAMINE Interactive Surface Plotting Commands
+
+:ncolumns   [value]	  Number of columns to be plotted
+:nlines	    [value]	  Number of lines to be plotted
+:axes	    [yes/no]	  Draw axes?
+:angh	    [value]	  Horizontal viewing angle
+:angv	    [value]	  Vertical viewing angle
+:floor	    [value]	  Minimum value to be plotted
+:ceiling    [value]	  Maximum value to be plotted
+
+
+	PEXAMINE Interactive Contour Plotting Commands
+
+:ncolumns   [value]	  Number of columns to be plotted
+:nlines	    [value]	  Number of lines to be plotted
+:floor	    [value]	  Minimum value to be plotted
+:ceiling    [value]	  Maximum value to be plotted
+:zero	    [value]       Greyscale value of zero contour
+:ncontours   [value]	  Number of contours to be drawn
+:interval    [value]       Contour interval
+:nhi	    [value]       Hi/low marking option
+:dashpat     [value]       Bit pattern for generating dashed lines
+:label       [yes/no]      Label major contours with their values?
+:box        [yes/no]      Draw box around periphery of window?
+:ticklabels [yes/no]	  Label tick marks?
+:majrx      [value]	  Number of major divisions along x axis
+:minrx      [value]	  Number of minor divisions along x axis
+:majry      [value]	  Number of major divisions along y axis
+:minry      [value]	  Number of minor divisions along y axis
+:round      [yes/no]      Round axes to nice values?
+:fill       [yes/no]      Fill viewport vs enforce unity aspect ratio?
+.fi
+
+.ih
+EXAMPLES
+
+1. Examine and edit an APPHOT aperture photometry catalog and a DAOPHOT
+allstar catalog without either attaching the associated image or using the
+image display.
+
+.nf
+    pt> pexamine m92.mag.1 m92.mag.ed use_display-
+
+	... a plot of magnitude error versus magnitude appears on
+	    the screen and the graphics cursor comes up ready to accept
+	    commands
+
+	... the user sees a generally smooth trend of increasing
+	    magnitude error with increasing magnitude except for a
+	    single deviant point at the bright end of the plot
+
+	... the user decides to remove the deviant point using the
+	    'd' keystroke command to mark the point and the 'f'
+	    keystroke command to actually delete and replot the graph
+
+	... after examining the plot further the user decides to delete
+	    all objects for which the magnitude error is > 0.1 magnitudes
+	    using the '^' keystroke command, followed by the 'f'
+	    keystroke command to actually replot and delete the data.
+
+	... after deciding that this new plot is satisfactory the user
+	    issues the 'e' keystroke command to exit pexamine and save
+	    the good data in m92.mag.ed
+
+    pt> pexamine m92.als.1 m92.als.ed use_display-
+
+	... a plot of magnitude error versus magnitude appears on the
+	    screen and the graphics cursor comes up ready to accept
+	    commands
+
+	... after looking at the plot the user decides that what they
+	    really want to see is a plot of the goodness of fit parameter
+	    chi versus magnitude
+
+	... the user issues the colon command :ycol chi followed by 'p'
+	    keystroke command to replot the data
+
+	... the user sees a generally smooth trend of increasing
+	    chi with increasing magnitude 
+
+	... after examining the plot further the user decides to delete
+	    all objects for which the chi value  > 2.0  and the
+	    magnitude is > 25 using the '^' key and ')' keystroke
+	    commands followed by 'f' to save the deletions and replot
+	    the data
+
+	... after deciding that this new plot is satisfactory the user
+	    issues the 'e' keystroke command to exit pexamine and save
+	    the good data in m92.als.ed
+.fi
+
+2. Examine and edit a DAOPHOT allstar catalog using the subracted image, the
+original image and the image display.
+
+.nf
+	pt> display image.sub 1
+
+	    ... display the subtracted image
+
+	pt> pexamine orionk.als.1 orionk.als.ed image xcol=mag ycol=chi
+
+	... a plot of the goodness of fit versus magnitude appears
+	    on the terminal and the graphics cursor comes up ready to
+	    accept commands
+
+	... the user notices some very anomalous chi values and decides
+	    to see if these correspond to objects which have poor
+	    subtraction on the displayed image
+
+	... the user switches to image command mode by tapping the 'i'
+	    key, moves to the first poorly subtracted object and taps
+	    the 'o' key
+
+	... a list of the values of the loaded columns including chi
+	    appears in the text window , the program switchs to graphics
+	    mode and places the graphics cursor on the corresponding
+	    point in the X-Y plot
+
+	... the point in question indeed has a very high chi value
+	    and the user decides to try and investigate the reason for the
+	    anomalous value
+
+	... the user taps the 'r' key to get a radial profile of the
+	    object in the original image
+
+	... after carefully examining the profile it appears that the
+	    object's profile is too broad and that it is not a star
+
+	... the user switches back to the X-Y plot with the 'x' key,
+	    marks the point with the 'd' key and saves the deletions
+	    and replots with the 'f' key.
+
+	... the user goes back to image command mode with the 'i' key
+	    and begins investigating the next object
+
+	... finally after examining the image and making all the changes
+	    the user decides to quit and save the changes with the 'e' key
+
+.fi
+
+.ih
+TIME REQUIREMENTS
+
+.ih
+BUGS
+If the display device is on a remote resource the first image cursor
+request will cause PEXAMINE to hang. The remote resource is expecting
+the appropriate password which the user must type in to cause the 
+the image cursor to appear. The normal password prompt is
+not being issued or flushed to the terminal. The solution to the problem
+is to put the password in the .irafhosts file
+
+INDEF valued points cannot be accessed by
+PEXAMINE. INDEF valued points should be removed from the input catalog
+with SELECT prior to entering PEXAMINE.
+
+.ih
+SEE ALSO
+ptools.select, ptools.txselect,ptools.tselect
+
+.endhelp
diff --git a/noao/digiphot/apphot/doc/phot.hlp b/noao/digiphot/apphot/doc/phot.hlp
new file mode 100644
index 00000000..a4ee6ffb
--- /dev/null
+++ b/noao/digiphot/apphot/doc/phot.hlp
@@ -0,0 +1,767 @@
+.help phot May00 noao.digiphot.apphot
+.ih
+NAME
+phot -- do aperture photometry on a list of stars
+.ih
+USAGE
+phot image
+.ih
+PARAMETERS
+.ls image
+The list of images containing the objects to be measured.
+.le
+.ls skyfile = ""
+The list of text files containing the sky values, of the measured objects,
+one object per line with x, y, the sky value, sky sigma, sky skew, number of sky
+pixels and number of rejected sky pixels in columns one to seven respectively.
+The number of sky files must be zero, one, or equal to the number of input
+images. A skyfile value is only requested if \fIfitskypars.salgorithm\fR =
+"file" and if PHOT is run non-interactively.
+.le
+.ls coords = ""
+The list of text files containing initial coordinates for the objects to
+be centered. Objects are listed in coords one object per line with the
+initial coordinate values in columns one and two. The number of coordinate
+files must be zero, one, or equal to the number of images.  If coords is
+"default", "dir$default", or a directory specification then a coords file name
+of the form dir$root.extension.version is constructed and searched for,
+where dir is the directory, root is the root image name, extension is "coo"
+and version is the next available version number for the file.
+.le
+.ls output = "default"
+The name of the results file or results directory. If output is
+"default", "dir$default", or a directory specification then an output file name
+of the form dir$root.extension.version is constructed, where dir is the
+directory, root is the root image name, extension is "mag" and version is
+the next available version number for the file. The number of output files
+must be zero, one, or equal to the number of image files.  In both interactive
+and batch mode full output is written to output. In interactive mode
+an output summary is also written to the standard output.
+.le
+.ls plotfile = ""
+The name of the file containing radial profile plots of the stars written
+to the output file. If plotfile is defined then a radial profile plot
+is written to plotfile every time a record is written to \fIoutput\fR.
+The user should be aware that this can be a time consuming operation.
+.le
+.ls datapars = ""
+The name of the file containing the data dependent parameters. The critical
+parameters \fIfwhmpsf\fR and \fIsigma\fR are located here. If \fIdatapars\fR
+is undefined then the default parameter set in uparm directory is used.
+.le
+.ls centerpars = ""
+The name of the file containing the centering parameters. The critical
+parameters \fIcalgorithm\fR and \fIcbox\fR are located here.
+If \fIcenterpars\fR is undefined then the default parameter set in 
+uparm directory is used.
+.le
+.ls fitskypars = ""
+The name of the text file containing the sky fitting parameters. The critical
+parameters \fIsalgorithm\fR, \fIannulus\fR, and \fIdannulus\fR are located here.
+If \fIfitskypars\fR is undefined then the default parameter set in uparm
+directory is used.
+.le
+.ls photpars = ""
+The name of the file containing the photometry parameters. The critical
+parameter \fIapertures\fR is located here.  If \fIphotpars\fR is undefined
+then the default parameter set in uparm directory is used.
+.le
+.ls interactive = yes
+Run the task interactively ?
+.le
+.ls radplots = no
+If \fIradplots\fR is "yes" and PHOT is run in interactive mode, a radial
+profile of each star is plotted on the screen after the star is measured.
+.le
+.ls icommands = ""
+The image display cursor or image cursor command file.
+.le
+.ls gcommands = ""
+The graphics cursor or graphics cursor command file.
+.le
+.ls wcsin = ")_.wcsin", wcsout = ")_.wcsout"
+The coordinate system of the input coordinates read from \fIcoords\fR and
+of the output coordinates written to \fIoutput\fR respectively. The image
+header coordinate system is used to transform from the input coordinate
+system to the "logical" pixel coordinate system used internally,
+and from the internal "logical" pixel coordinate system to the output
+coordinate system. The input coordinate system options are "logical", tv",
+"physical", and "world". The output coordinate system options are "logical",
+"tv", and "physical". The image cursor coordinate system is assumed to
+be the "tv" system.
+.ls logical
+Logical coordinates are pixel coordinates relative to the current image.
+The  logical coordinate system is the coordinate system used by the image
+input/output routines to access the image data on disk. In the logical
+coordinate system the coordinates of the first pixel of a  2D image, e.g.
+dev$ypix  and a 2D image section, e.g. dev$ypix[200:300,200:300] are
+always (1,1).
+.le
+.ls tv
+Tv coordinates are the pixel coordinates used by the display servers. Tv
+coordinates  include  the effects of any input image section, but do not
+include the effects of previous linear transformations. If the input
+image name does not include an image section, then tv coordinates are
+identical to logical coordinates.  If the input image name does include a
+section, and the input image has not been linearly transformed or copied from
+a parent image, tv coordinates are identical to physical coordinates.
+In the tv coordinate system the coordinates of the first pixel of a
+2D image, e.g. dev$ypix and a 2D image section, e.g. dev$ypix[200:300,200:300]
+are (1,1) and (200,200) respectively.
+.le
+.ls physical
+Physical coordinates are pixel coordinates invariant  with respect to linear
+transformations of the physical image data.  For example, if the current image
+was created by extracting a section of another image,  the  physical
+coordinates of an object in the current image will be equal to the physical
+coordinates of the same object in the parent image,  although the logical
+coordinates will be different.  In the physical coordinate system the
+coordinates of the first pixel of a 2D image, e.g. dev$ypix and a 2D
+image section, e.g. dev$ypix[200:300,200:300] are (1,1) and (200,200)
+respectively.
+.le
+.ls world
+World coordinates are image coordinates in any units which are invariant
+with respect to linear transformations of the physical image data. For
+example, the ra and dec of an object will always be the same no matter
+how the image is linearly transformed. The units of input world coordinates
+must be the same as those expected by the image header wcs, e. g.
+degrees and degrees for celestial coordinate systems.
+.le
+The wcsin and wcsout parameters default to the values of the package
+parameters of the same name. The default values of the package parameters
+wcsin and wcsout are "logical" and "logical" respectively.
+.le
+.le
+.ls cache = ")_.cache"
+Cache the image pixels in memory. Cache may be set to the value of the apphot
+package parameter (the default), "yes", or "no". By default cacheing is 
+disabled.
+.le
+.ls verify = ")_.verify"
+Verify the critical parameters in non-interactive mode.  Verify may
+be set to the value of the apphot package parameter (the default), "yes", or
+"no".
+.le
+.ls update = ")_.update"
+Automatically update the  algorithm parameters in non-interactive mode
+if verify is "yes". Update may be set to the value of the apphot
+package parameter (the default), "yes", or "no".
+.le
+.ls verbose = ")_.verbose"
+Print results on the screen in non-interactive mode? Verbose may
+be set to the value of the apphot package parameter (the default),
+"yes", or "no".
+.le
+.ls graphics = ")_.graphics"
+The default graphics device. Graphics may be set to the value of the apphot
+package parameter (the default), "yes", or "no".
+.le
+.ls display = ")_.display"
+The default display device.  Display may be set to the apphot package
+parameter value (the default), "yes", or "no.  By default graphics overlay is
+disabled.  Setting display to one of "imdr", "imdg", "imdb", or "imdy" enables
+graphics overlay with the IMD graphics kernel.  Setting display to
+"stdgraph" enables PHOT to work interactively from a contour plot.
+.le
+
+.ih
+DESCRIPTION
+
+PHOT computes accurate centers, sky values, and magnitudes for a list of
+objects in the IRAF image \fIimage\fR whose coordinates are read from
+the text file \fIcoords\fR or the image display cursor, and writes the
+computed x and y coordinates, sky values, and magnitudes to the text
+file \fIoutput\fR.
+
+The coordinates read from \fIcoords\fR are assumed to be in coordinate
+system defined by \fIwcsin\fR. The options are "logical", "tv", "physical",
+and "world" and the transformation from the input coordinate system to
+the internal "logical" system is defined by the image coordinate system.
+The simplest default is the "logical" pixel system. Users working on with
+image sections but importing pixel coordinate lists generated from the parent
+image must use the "tv" or "physical" input coordinate systems.
+Users importing coordinate lists in world coordinates, e.g. ra and dec,
+must use the "world" coordinate system and may need to convert their
+equatorial coordinate units from hours and degrees to degrees and degrees first.
+
+The coordinates written to \fIoutput\fR are in the coordinate
+system defined by \fIwcsout\fR. The options are "logical", "tv",
+and "physical". The simplest default is the "logical" system. Users
+wishing to correlate the output coordinates of objects measured in
+image sections or mosaic pieces with coordinates in the parent
+image must use the "tv" or "physical" coordinate systems.
+
+In interactive mode the user may either define the list of objects to be
+measured interactively with the image curspr or create an object list prior
+to running PHOT. In either case the user may adjust the centering, sky fitting,
+ and photometry algorithm parameters until a satisfactory fit is achieved
+and optionally store the final results in \fIoutput\fR. In batch mode the
+initial positions are read from the text file \fIcoords\fR or the image
+cursor parameter \fIicommands\fR can be redirected to a text file containing
+a list of cursor commands. In batch mode the current set of algorithm
+parameters is used.
+
+If \fIcache\fR is yes and the host machine physical memory and working set size
+are large enough, the input image pixels are cached in memory. If cacheing
+is enabled and PHOT is run interactively the first measurement will appear
+to take a long time as the entire image must be read in before the measurement
+is actually made. All subsequent measurements will be very fast because PHOT
+is accessing memory not disk. The point of cacheing is to speed up random
+image access by making the internal image i/o buffers the same size as the
+image itself. However if the input object lists are sorted in row order and
+sparse cacheing may actually worsen not improve the execution time. Also at
+present there is no point in enabling cacheing for images that are less than
+or equal to 524288 bytes, i.e. the size of the test image dev$ypix, as the
+default image i/o buffer is exactly that size. However if the size of dev$ypix
+is doubled by converting it to a real image with the chpixtype task then the
+effect of cacheing in interactive is can be quite noticeable if measurements
+of objects in the top and bottom halfs of the image are alternated.
+
+PHOT computes accurate centers for each object using the centering
+parameters defined in \fIcenterpars\fR, computes an accurate sky value
+for each object using the sky fitting parameters defined in \fIfitskypars\fR,
+and computes magnitudes using the photometry parameters defined in
+\fIphotpars\fR. The image data characteristics of the data are specified
+in \fIdatapars\fR.
+
+.ih
+CURSOR COMMANDS
+
+The following list of cursor commands are currently available.
+
+.nf
+	Interactive Keystroke Commands
+
+?	Print help
+:	Colon commands
+v	Verify the critical parameters
+w	Save the current parameters
+d	Plot radial profile of current star
+i	Interactively set parameters using current star
+c	Fit center for current star
+t	Fit sky around the cursor
+a	Average sky values fit around several cursor positions
+s	Fit sky around current centered star
+p	Do photometry for current star, using current sky
+o	Do photometry for current star, using current sky, output results
+f	Do photometry for current star
+spbar	Do photometry for current star, output results
+m	Move to next star in coordinate list
+n	Do photometry for next star in coordinate list, output results
+l	Do photometry for remaining stars in coordinate list, output results
+e	Print error messages
+r	Rewind coordinate list
+q	Exit task
+
+
+Photometry parameters are listed or set with the following commands.
+
+	Colon commands
+
+:show	[data/center/sky/phot]	List the parameters
+:m [n]	Move to next [nth] star in coordinate list
+:n [n]	Do photometry for next [nth] star in coordinate list, output results
+
+	Colon Parameter Editing Commands
+
+# Image and file name parameters
+
+:image		[string]	Image name
+:coords		[string]	Coordinate file name
+:output		[string]	Output file name
+
+# Data dependent parameters
+
+:scale		[value]		Image scale (units per pixel)
+:fwhmpsf	[value]		Full width half maximum of PSF (scale units)
+:emission	[y/n]		Emission feature (y), absorption (n)
+:sigma	        [value]		Standard deviation of sky (counts)
+:datamin	[value]		Minimum good data value (counts)
+:datamax	[value]		Maximum good data value (counts)
+
+# Noise parameters
+
+:noise		[string]	Noise model (constant|poisson)
+:gain		[string]	Gain image header keyword
+:ccdread	[string]	Readout noise image header keyword
+:epadu		[value]		Gain (electrons  per adu)
+:readnoise	[value]		Readout noise (electrons)
+
+# Observations parameters
+
+:exposure	[string]	Exposure time image header keyword
+:airmass	[string]	Airmass image header keyword
+:filter		[string]	Filter image header keyword
+:obstime	[string]	Time of observation image header keyword
+:itime 		[value]		Integration time (time units)
+:xairmass	[value]		Airmass value (number)
+:ifilter	[string]	Filter id string
+:otime		[string]	Time of observation (time units)
+
+# Centering algorithm parameters
+
+:calgorithm	[string]	Centering algorithm
+:cbox		[value]		Width of the centering box (scale units)
+:cthreshold	[value]		Centering intensity threshold (sigma)
+:cmaxiter	[value]		Maximum number of iterations
+:maxshift	[value]		Maximum center shift (scale units)
+:minsnratio	[value]		Minimum S/N ratio for centering
+:clean		[y/n]		Clean subraster before centering
+:rclean		[value]		Cleaning radius (scale units)
+:rclip		[value]		Clipping radius (scale units)
+:kclean		[value]		Clean K-sigma rejection limit (sigma)
+
+# Sky fitting algorithm parameters
+
+:salgorithm	[string]	Sky fitting algorithm
+:skyvalue	[value]		User supplied sky value (counts)
+:annulus	[value]		Inner radius of sky annulus (scale units)
+:dannulus	[value]		Width of sky annulus (scale units)
+:khist		[value]		Sky histogram extent (+/- sky sigma)
+:binsize	[value]		Resolution of sky histogram (sky sigma)
+:smooth		[y/n]		Lucy smooth the sky histogram
+:sloclip	[value]	        Low-side clipping factor in percent
+:shiclip	[value]	        High-side clipping factor in percent
+:smaxiter	[value]		Maximum number of iterations
+:snreject	[value]		Maximum number of rejection cycles
+:sloreject	[value]		Low-side pixel rejection limits (sky sigma)
+:shireject	[value]		High-side pixel rejection limits (sky sigma)
+:rgrow		[value]		Region growing radius (scale units)
+
+# Photometry parameters
+
+:apertures	[string]	List of aperture radii (scale units)
+:zmag		[value]		Zero point of magnitude scale
+
+# Plotting and marking parameters
+
+:mkcenter	[y/n]		Mark computed centers on display
+:mksky		[y/n]		Mark the sky annuli on the display
+:mkapert	[y/n]		Mark apertures on the display
+:radplot	[y/n]		Plot radial profile of object
+
+
+                    Interactive Phot Setup Menu
+
+	v	 Mark and verify the critical parameters (f,s,c,a,d,r)
+
+	f	 Mark and verify the full-width half-maximum of psf
+	s	 Mark and verify the standard deviation of the background
+	l	 Mark and verify the minimum good data value
+	u	 Mark and verify the maximum good data value
+
+	c	 Mark and verify the centering box width
+	n	 Mark and verify the cleaning radius
+	p	 Mark and verify the clipping radius
+
+	a	 Mark and verify the inner radius of the sky annulus
+	d	 Mark and verify the width of the sky annulus
+	g	 Mark and verify the region growing radius
+
+	r	 Mark and verify the aperture radii
+.fi
+
+.ih
+ALGORITHMS
+
+A brief description of the data dependent parameters, centering algorithms,
+sky fitting algorithms and photometry parameters can be found in the
+online help pages for the DATAPARS, CENTERPARS, FITSKYPARS, and PHOTPARS
+tasks.
+
+.ih
+OUTPUT
+
+In interactive mode the following quantities are printed on the standard
+output as each object is measured. Err is a simple string indicating whether
+or not an error was detected in the centering algorithm, the sky fitting
+algorithm or the photometry algorithm. Mag are the magnitudes in apertures 1
+through N respectively and xcenter, ycenter and msky are the x and y centers
+and the sky value respectively.
+
+.nf
+    image  xcenter  ycenter  msky  mag[1 ... N]  error
+.fi
+
+In both interactive and batch mode full output is written to the text file
+\fIoutput\fR. At the beginning of each file is a header listing the
+current values of the parameters when the first stellar record was written.
+These parameters can be subsequently altered. For each star measured the
+following record is written
+
+.nf
+	image  xinit  yinit  id  coords  lid
+	   xcenter  ycenter  xshift  yshift  xerr  yerr  cier error
+	   msky  stdev  sskew  nsky  nsrej  sier  serror
+	   itime  xairmass  ifilter  otime
+	   rapert  sum  area  flux mag  merr  pier  perr
+.fi
+
+Image and coords are the name of the image and coordinate file respectively.
+Id and lid are the sequence numbers of stars in the output and coordinate
+files respectively. Cier and cerror are the centering algorithm error code
+and accompanying error message respectively.  Xinit, yinit, xcenter, ycenter,
+xshift, yshift, and xerr, yerr are self explanatory and output in pixel units.
+The sense of the xshift and yshift definitions is the following.
+
+.nf
+	xshift = xcenter - xinit
+	yshift = ycenter - yinit
+.fi
+
+Sier and serror are the sky fitting error code and accompanying error
+message respectively. Msky, stdev and sskew are the best estimate of the sky
+value (per pixel), standard deviation and skew respectively. Nsky and nsrej
+are the number of sky pixels and the number of sky pixels rejected respectively.
+
+Itime is the exposure time, xairmass is self-evident, ifilter is an
+id string identifying the filter used in the observations, and otime is
+a string containing the time of the observation in whatever units the
+user has set up.
+
+Rapert, sum, area, and flux  are the radius of the aperture in scale units,
+the total number of counts including sky in the aperture, the area of the
+aperture in square pixels, and the total number of counts excluding sky
+in the aperture. Mag and merr are the magnitude and error in the magnitude
+in the aperture (see below).
+
+.nf
+	flux = sum - area * msky
+	 mag = zmag - 2.5 * log10 (flux) + 2.5 * log10 (itime)
+	merr = 1.0857 * error / flux
+       error = sqrt (flux / epadu + area * stdev**2 +
+               area**2 * stdev**2 / nsky)
+.fi
+
+Pier and perror are photometry error code and accompanying error message.
+
+In interactive mode a radial profile of each measured object is plotted
+in the graphics window if \fIradplots\fR is "yes".
+
+In interactive and batchmode a radial profile plot is written to
+\fIplotfile\fR  if it is defined each time the result of an object
+measurement is written to \fIoutput\fR .
+
+.ih
+ERRORS
+
+If the object centering was error free then the field cier will be zero.
+Non-zero values of cier flag the following error conditions.
+
+.nf
+	0        # No error
+	101      # The centering box is off image
+	102      # The centering box is partially off the image
+	103      # The S/N ratio is low in the centering box
+	104      # There are two few points for a good fit
+	105      # The x or y center fit is singular
+	106      # The x or y center fit did not converge
+	107      # The x or y center shift is greater than maxshift
+	108      # There is bad data in the centering box
+.fi
+
+If all goes well during the sky fitting process then the error code sier
+will be 0. Non-zero values of sier flag the following error conditions.
+
+.nf
+	0         # No error
+	201       # There are no sky pixels in the sky annulus
+	202       # Sky annulus is partially off the image
+	203       # The histogram of sky pixels has no width
+	204       # The histogram of sky pixels is flat or concave
+	205       # There are too few points for a good sky fit
+	206       # The sky fit is singular
+	207       # The sky fit did not converge
+	208       # The graphics stream is undefined
+	209       # The file of sky values does not exist
+	210       # The sky file is at EOF
+	211       # Cannot read the sky value correctly
+	212       # The best fit parameter are non-physical
+.fi
+
+If no error occursor during the measurement of the magnitudes then pier is
+0. Non-zero values of pier flag the following error conditions.
+
+.nf
+	0         # No error
+	301       # The aperture is off the image
+	302       # The aperture is partially off the image
+	303       # The sky value is undefined
+	305       # There is bad data in the aperture
+.fi
+
+.ih
+EXAMPLES
+
+1. Compute the magnitudes for a few  stars in dev$ypix using the display
+and the image cursor. Setup the task parameters using the interactive
+setup menu defined by the i key command and a radial profile plot.
+
+.nf
+	ap> display dev$ypix 1 fi+
+
+	... display the image
+
+	ap> phot dev$ypix
+
+	... type ? to print an optional help page
+
+	... move the image cursor to a star
+	... type i to enter the interactive setup menu
+	... enter maximum radius in pixels of the radial profile or hit
+            CR to accept the default
+	... set the fwhmpsf, centering radius, inner and outer sky annuli,
+	    photometry apertures, and sigma using the graphics cursor and
+	    the stellar radial profile plot
+	... typing <CR> leaves everything at the default value
+        ... type q to quit the setup menu
+
+	... type the v key to verify the parameters
+
+	... type the w key to save the parameters in the parameter files
+
+	... move the image cursor to the stars of interest and tap
+	    the space bar
+
+	... a one line summary of the fitted parameters will appear on the
+	    standard output for each star measured
+
+	... type q to quit and q again to confirm the quit
+
+	... the output will appear in ypix.mag.1
+.fi
+
+2. Compute the magnitudes for a few stars in dev$ypix using a contour plot
+and the graphics cursor. This option is only useful for those (now very few)
+users who have access to a graphics terminal but not to an image display
+server. Setup the task parameters using the interactive setup menu defined by
+the i key command as in example 1.
+
+.nf
+        ap> show stdimcur
+
+        ... record the default value of stdimcur
+
+	ap> set stdimcur = stdgraph
+
+	... define the image cursor to be the graphics cursor
+
+        ap> contour dev$ypix
+
+        ... make a contour plot of dev$ypix
+
+	ap> contour dev$ypix >G ypix.plot1
+
+	... store the contour plot of dev$ypix in the file ypix.plot1
+
+	ap> phot dev$ypix display=stdgraph
+
+	... type ? to get an optional help page
+
+	... move graphics cursor to a star
+	... type i to enter the interactive setup menu
+	... enter maximum radius in pixels of the radial profile or CR
+            to accept the default value
+	... set the fwhmpsf, centering radius, inner and outer sky annuli,
+	    apertures, and sigma using the graphics cursor and the
+            stellar radial profile plot
+	... typing <CR> leaves everything at the default value
+        ... type q to quit the setup menu
+
+	... type the v key to verify the critical parameters
+
+	... type the w key to save the parameters in the parameter files
+
+	... retype :.read ypix.plot1 to reload the contour plot
+
+	... move the graphics cursor to the stars of interest and tap
+	    the space bar
+
+	... a one line summary of the fitted parameters will appear on the
+	    standard output for each star measured
+
+	... type q to quit and q again to verify
+
+	... full output will appear in the text file ypix.mag.2 
+
+        ap> set stdimcur = <default>
+
+        ... reset stdimcur to its previous value
+.fi
+
+
+3. Setup and run PHOT interactively on a list of objects temporarily
+overriding the fwhmpsf, sigma, cbox, annulus, dannulus, and apertures
+parameters determined in examples 1 or 2.
+
+.nf
+        ap> daofind dev$ypix fwhmpsf=2.6 sigma=25.0 verify-
+
+        ... make a coordinate list
+
+        ... the output will appear in the text file ypix.coo.1
+
+        ap> phot dev$ypix cbox=7.0 annulus=12.0 dannulus=5.0 \
+           apertures="3.0,5.0" coords=ypix.coo.1
+
+        ... type ? for optional help
+
+
+        ... move the graphics cursor to the stars and tap space bar
+
+                                or
+
+        ... select stars from the input coordinate list with m / :m #
+            and measure with spbar
+
+        ... measure stars selected from the input coordinate list
+            with n / n #
+
+        ... a one line summary of results will appear on the standard output
+            for each star measured
+
+        ... type q to quit and q again to confirm the quit
+
+        ... the output will appear in ypix.mag.3 ...
+.fi
+
+
+4. Display and measure some stars in an image section and write the output
+coordinates in the coordinate system of the parent image.
+
+.nf
+        ap> display dev$ypix[150:450,150:450] 1
+
+        ... display the image section
+
+        ap> phot dev$ypix[150:450,150:450] wcsout=tv
+
+        ... move cursor to stars and type spbar
+
+        ... type q to quit and q again to confirm quit
+
+        ... output will appear in ypix.mag.4
+
+        ap> pdump ypix.mag.4 xc,yc yes | tvmark 1 STDIN col=204
+.fi
+
+5. Run PHOT in batch mode using the coordinate file and the previously
+saved parameters. Verify the critical parameters.
+
+.nf
+        ap> phot dev$ypix coords=ypix.coo.1 verify+ inter-
+
+        ... output will appear in ypix.mag.5 ...
+.fi
+
+6. Repeat example 5 but assume that the input coordinate are ra and dec
+in degrees and degrees, turn off verification, and submit the task to to
+the background.
+
+.nf
+        ap> display dev$ypix 1
+
+        ap> rimcursor wcs=world > radec.coo
+
+        ... move to selected stars and type any key
+
+        ... type ^Z to quit
+
+        ap> phot dev$ypix coords=radec.coo wcsin=world verify- inter- &
+
+        ... output will appear in ypix.mag.6
+
+        ap> pdump ypix.mag.6 xc,yc yes | tvmark 1 STDIN col=204
+
+        ... mark the stars on the display
+.fi
+
+
+7. Run PHOT interactively without using the image display.
+
+.nf
+        ap> show stdimcur
+
+        ... record the default value of stdimcur
+
+        ap> set stdimcur = text
+
+        ... set the image cursor to the standard input
+
+        ap> phot dev$ypix coords=ypix.coo.1
+
+        ... type ? for optional help
+
+        ... type :m 3 to set the initial coordinates to those of the
+            third star in the list
+
+        ... type i to enter the interactive setup menu
+        ... enter the maximum radius in pixels for the radial profile or
+            accept the default with a CR
+        ... type v to enter the default menu
+	... set the fwhmpsf, centering radius, inner and outer sky annuli,
+	    apertures, and sigma using the graphics cursor and the
+            stellar radial profile plot
+        ... typing <CR> after the prompt leaves the parameter at its default
+            value
+	... type q to quit the setup menu
+
+        ... type r to rewind the coordinate list
+
+        ... type l to measure all the stars in the coordinate list
+
+        ... a one line summary of the answers will appear on the standard
+            output for each star measured
+
+        ... type q to quit followed by q to confirm the quit
+
+        ... full output will appear in the text file ypix.mag.7
+
+        ap> set stdimcur = <default>
+
+        ... reset the value of stdimcur
+.fi
+
+8. Use a image cursor command file to drive the PHOT task. The cursor command
+file shown below sets the cbox, annulus, dannulus, and apertures parameters
+computes the centers, sky values, and magnitudes for 3 stars, updates the
+parameter files, and quits the task.
+
+.nf
+        ap> type cmdfile
+        : cbox 9.0
+        : annulus 12.0
+        : dannulus 5.0
+        : apertures 5.0
+        442 410 101 \040
+        349 188 101 \040
+        225 131 101 \040
+        w
+        q
+
+        ap> phot dev$ypix icommands=cmdfile  verify-
+
+        ... full output will appear in ypix.mag.8
+.fi
+
+
+.ih
+BUGS
+
+It is currently the responsibility of the user to make sure that the
+image displayed in the frame is the same as that specified by the image
+parameter.
+
+Commands which draw to the image display are disabled by default.
+To enable graphics overlay on the image display, set the display
+parameter to "imdr", "imdg", "imdb", or "imdy" to get red, green,
+blue or yellow overlays and set the centerpars mkcenter switch to
+"yes", the fitskypars mksky switch to"yes", or the photpars mkapert
+switch to "yes". It may be necessary to run gflush and to redisplay the image
+to get the overlays position correctly.
+
+.ih
+SEE ALSO
+datapars, centerpars, fitskypars, photpars, qphot, wphot, polyphot
+.endhelp
diff --git a/noao/digiphot/apphot/doc/photpars.hlp b/noao/digiphot/apphot/doc/photpars.hlp
new file mode 100644
index 00000000..0a172ba3
--- /dev/null
+++ b/noao/digiphot/apphot/doc/photpars.hlp
@@ -0,0 +1,102 @@
+.help photpars May00 noao.digiphot.apphot
+.ih
+NAME
+photpars -- edit the photometry parameters
+.ih
+USAGE
+photpars
+.ih
+PARAMETERS
+.ls weighting = "constant"
+The type of weighting for the WPHOT task. The weighting parameter is
+ignored by the PHOT task. The options are:
+.ls constant
+Uniform weights of 1 for each pixel are used.
+.le
+.ls cone
+A conical weighting function of full width half maximum \fIfwhmpsf\fR as
+defined in the DATAPARS parameter set is used.
+.le
+.ls gauss
+A Gaussian weighting function of full width half maximum \fIfwhmpsf\fR as
+defined in the DATAPARS parameter set is used.
+.le
+.le
+.ls apertures = "3" (scale units)
+A list of aperture radii in units of the  scale parameter or the name of the
+file containing the list of aperture radii. List elements may be separated by
+whitespace or commas. A range syntax of the form ap1:apN:apstep is also
+supported. 
+.le
+.ls zmag = 25.00
+The zero point offset for the magnitude scale.
+.le
+.ls mkapert = no
+Mark the photometry apertures on the displayed image ?
+.le
+
+.ih
+DESCRIPTION
+
+The integral of the flux within the circular apertures specified by
+\fIapertures\fR is computed by summing pixels in the aperture with
+the specified weighting function \fIweighting\fR. The fraction of each pixel
+lying within the aperture is computed by an approximation and all the
+approximations are summed.  The zero point of the magnitude
+scale is determined by \fIzmag\fR.
+
+\fRApertures\fR is specified in units of the image scale. If \fIscale\fR
+is specified in units of the half-width at half-maximum of the point
+spread function the aperture per pixel  a single value of apertures
+will work well on images with differing psfs.
+
+.ih
+EXAMPLES
+
+1. List the PHOTPARS parameters.
+
+.nf
+    da> lpar photpars
+.fi
+
+2. Edit the PHOTPARS parameters.
+
+.nf
+    da> photpars
+.fi
+
+3. Edit the PHOTPARS parameters from within the PHOT task.
+
+.nf
+    da> epar phot
+
+	... edit a few phot parameters
+
+	... move to the photpars parameter and type :e
+
+	... edit the photpars parameters and type :wq
+
+	... finish editing the phot parameters and type :wq
+
+.fi
+
+4. Save the current PHOTPARS parameter set in a text file photnite1.par.
+This can also be done from inside a higher level task as in the
+above example.
+
+.nf
+    da> photpars
+
+	... edit some parameters
+
+	... type ":w photnite1.par"  from within epar
+.fi
+
+.ih
+TIME REQUIREMENTS
+.ih
+BUGS
+.ih
+SEE ALSO
+phot,wphot,radprof
+.endhelp
diff --git a/noao/digiphot/apphot/doc/polymark.hlp b/noao/digiphot/apphot/doc/polymark.hlp
new file mode 100644
index 00000000..e88bc089
--- /dev/null
+++ b/noao/digiphot/apphot/doc/polymark.hlp
@@ -0,0 +1,430 @@
+.help polymark May00 noao.digiphot.apphot
+.ih
+NAME
+polymark -- create or review polygon and coordinate lists for input to the
+polyphot task
+.ih
+USAGE
+polymark image
+.ih
+PARAMETERS
+.ls images
+The list of input images used to define the polygons.
+.le
+.ls coords = "default"
+The input / output center positions file. The center positions for each
+polygonal aperture are read from or written to coords. There may more than one
+center position per polygon. Center positions are written to coords 1 center
+position per line. When the current polygon changes POLYMARK inserts a line
+containing a single ';' after the last center position. If coords is
+"default", "dir$default" or a directory specification then a center position
+file name of the form dir$root.extension.version is constructed, where dir is
+the directory, root is the root image name, extension is "coo" and version is
+the next available version of the file. 
+.le
+.ls polygons = "default"
+The name of the polygons file. The vertices of each polygon  are read from or
+written to the polygons file. The polygons file contains a list of the
+polygon vertices. Each vertex list is terminated by a line containing a  ';'
+after the last vertex. If polygons is "default", "dir$default" or a directory
+specification then an output name of the form dir$root.extension.version is
+constructed, where dir is the directory, root is the root image name, extension
+is "ver" and the version is next available version of the file. The number of
+polygon files must be equal to the number of image files.
+.le
+.ls icommands = ""
+The image cursor or image cursor command file.
+.le
+.ls gcommands = ""
+The graphics cursor or graphics cursor command file.
+.le
+.ls wcsin = ")_.wcsin", wcsout = ")_.wcsout"
+The coordinate system of the input coordinates read from or written
+to \fIcoords\fR and \fIpolygons\fR. The image header coordinate system is
+used to transform from the input coordinate system to the "logical" pixel
+coordinate system used internally, and from the internal "logical" pixel
+coordinate system to the output coordinate system. The input coordinate
+system options are "logical", tv", "physical", and "world". The output
+coordinate system options are "logical", "tv", and "physical". The image
+cursor coordinate system is assumed to be the "tv" system.
+.ls logical
+Logical coordinates are pixel coordinates relative to the current image.
+The  logical coordinate system is the coordinate system used by the image
+input/output routines to access the image data on disk. In the logical
+coordinate system the coordinates of the first pixel of a  2D image, e.g.
+dev$ypix  and a 2D image section, e.g. dev$ypix[200:300,200:300] are
+always (1,1).
+.le
+.ls tv
+Tv coordinates are the pixel coordinates used by the display servers. Tv
+coordinates  include  the effects of any input image section, but do not
+include the effects of previous linear transformations. If the input
+image name does not include an image section, then tv coordinates are
+identical to logical coordinates.  If the input image name does include a
+section, and the input image has not been linearly transformed or copied from
+a parent image, tv coordinates are identical to physical coordinates.
+In the tv coordinate system the coordinates of the first pixel of a
+2D image, e.g. dev$ypix and a 2D image section, e.g. dev$ypix[200:300,200:300]
+are (1,1) and (200,200) respectively.
+.le
+.ls physical
+Physical coordinates are pixel coordinates invariant  with respect to linear
+transformations of the physical image data.  For example, if the current image
+was created by extracting a section of another image,  the  physical
+coordinates of an object in the current image will be equal to the physical
+coordinates of the same object in the parent image,  although the logical
+coordinates will be different.  In the physical coordinate system the
+coordinates of the first pixel of a 2D image, e.g. dev$ypix and a 2D
+image section, e.g. dev$ypix[200:300,200:300] are (1,1) and (200,200)
+respectively.
+.le
+.ls world
+World coordinates are image coordinates in any units which are invariant
+with respect to linear transformations of the physical image data. For
+example, the ra and dec of an object will always be the same no matter
+how the image is linearly transformed. The units of input world coordinates
+must be the same as those expected by the image header wcs, e. g.
+degrees and degrees for celestial coordinate systems.
+.le
+The wcsin and wcsout parameters default to the values of the package
+parameters of the same name. The default values of the package parameters
+wcsin and wcsout are "logical" and "logical" respectively.
+.le
+.ls cache = ")_.cache"
+Cache the image pixels in memory. Cache may be set to the value of the apphot
+package parameter (the default), "yes", or "no". By default cacheing is 
+disabled.
+.le
+.ls graphics = ")_.graphics"
+The standard graphics device.
+.le
+.ls display = ")_.display"
+The default display device.  Display may be set to the apphot package
+parameter value (the default), "yes", or "no.  By default graphics overlay is
+disabled.  Setting display to one of "imdr", "imdg", "imdb", or "imdy" enables
+graphics overlay with the IMD graphics kernel.  Setting display to
+"stdgraph" enables POLYMARK to work interactively from a contour plot.
+.le
+
+.ih
+DESCRIPTION
+
+POLYMARK creates and / or displays center position and polygons files
+suitable for input to POLYPHOT. For each image in the input list POLYMARK
+creates a polygons file \fIpolygons\fR and center positions file \fIcoords\fR, 
+if these do not already exist. The format of the polygons and center
+position files is described in the OUTPUT section. 
+
+Polygonal apertures are defined and drawn on the image display using
+the image display cursor and then shifted to the desired center
+using the image display cursor. At any point in the marking process
+the user may rewind the polygon and coordinate file and draw the previously
+defined polygons on the display.
+
+The coordinates read from \fIpolygons\fR or  \fIcoords\fR are assumed to be
+in coordinate system defined by \fIwcsin\fR. The options are "logical", "tv",
+"physical", and "world" and the transformation from the input coordinate
+system to the internal "logical" system is defined by the image coordinate
+system.  The simplest default is the "logical" pixel system. Users working on
+with image sections but importing pixel coordinate lists generated from the
+parent image must use the "tv" or "physical" input coordinate systems.
+Users importing coordinate lists in world coordinates, e.g. ra and dec,
+must use the "world" coordinate system and may need to convert their
+equatorial coordinate units from hours and degrees to degrees and degrees first.
+
+The coordinates written to \fIpolygons\fR or \fIcoords\fR are in the coordinate
+system defined by \fIwcsout\fR. The options are "logical", "tv", and
+"physical". The simplest default is the "logical" system. Users
+wishing to correlate the output coordinates of objects measured in
+image sections or mosaic pieces with coordinates in the parent
+image must use the "tv" or "physical" coordinate systems.
+
+If \fIcache\fR is yes and the host machine physical memory and working set size
+are large enough, the input image pixels are cached in memory. If cacheing
+is enabled and POLYMARK is run interactively the first measurement will appear
+to take a long time as the entire image must be read in before the measurement
+is actually made. All subsequent measurements will be very fast because POLYMARK
+is accessing memory not disk. The point of cacheing is to speed up random
+image access by making the internal image i/o buffers the same size as the
+image itself. However if the input object lists are sorted in row order and
+sparse cacheing may actually worsen not improve the execution time. Also at
+present there is no point in enabling cacheing for images that are less than
+or equal to 524288 bytes, i.e. the size of the test image dev$ypix, as the
+default image i/o buffer is exactly that size. However if the size of dev$ypix
+is doubled by converting it to a real image with the chpixtype task then the
+effect of cacheing in interactive is can be quite noticeable if measurements
+of objects in the top and bottom halfs of the image are alternated.
+.ih
+CURSOR COMMANDS
+
+The following interactive keystroke and colon commands are available.
+
+.nf
+	Interactive Keystroke Commands
+
+?	Print help
+:	Colon commands 
+d	Plot radial profile of star near cursor
+g	Define the current polygonal aperture
+f	Draw the current polygon on the display
+spbar	Draw the current polygon on the display, output the polygon
+r	Rewind the polygon list
+m	Draw the next polygon in the polygon list on the display
+l	Draw all the remaining polygons in the list on the display
+q	Exit
+
+	Colon commands
+
+:m [n]	Draw the next [nth] polygon in the polygon list on the display
+.fi
+
+.ih
+OUTPUT
+
+A sample polygons file and accompanying coordinates file is listed below.
+
+.nf
+	# Sample Polygons File (2 polygons)
+
+	200.5  200.5
+	300.5  200.5
+	300.5  300.5
+	200.5  300.5
+	;
+	100.4  100.4
+	120.4  100.4
+	120.4  120.4
+	100.4  120.4
+	;
+.fi
+
+.nf
+	# Sample Coordinates File (2 groups, 1 for each polygon)
+
+	123.4  185.5
+	110.4  130.4
+	150.9  200.5
+	;
+	85.6   35.7
+	400.5  300.5
+	69.5   130.5
+	;
+.fi
+
+.ih
+EXAMPLES
+
+1. Create a coordinate list and polygon file using the image display and
+image display cursor. Use polymark to both create and display the 
+polygon and polygon center lists.
+
+.nf
+	ap> display dev$ypix 1 fi+ 
+
+	... display the image
+
+	ap> polymark dev$ypix display=imdg
+
+	... type ? for an optional help page 
+
+	... type g to enter the "define a polygon" menu
+	... move the cursor to the first vertex, tap the space bar
+	    to mark the vertex, and repeat for each vertex
+	... type q to quit the "define a polygon" menu
+	... mark each vertex only once, POLYPHOT will close the
+	    polygon for you
+
+	... move the cursor to the desired polygon center and
+	    tap the space bar to record the polygon
+	... repeat for all desired polygon centers
+
+	... type g to define the next polygon
+	... move the cursor to the first vertex, tap the space bar
+	    to mark the vertex and repeat for each vertex
+	... type q to quit the polygon menu
+	... mark each vertex only once, POLYPHOT will close the
+	    polygon for you
+
+	... move the cursor to the desired polygon center and
+	    tap the space bar
+	... repeat for all desired polygon centers
+
+	... type q to quit and q to confirm the quit
+
+	... output will appear in ypix.coo.1 and ypix.ver.1
+
+
+	ap> display dev$ypix 2 fi+ 
+
+	... display the image
+
+	ap> polymark dev$ypix coords=ypix.coo.1 polygons=ypix.ver.1 \
+	    display=imdg
+
+	... type m to mark the first polygon / polygon center on the display
+
+	... type m to mark the next polygon / polygon center on the display
+
+	... type l to mark the remaining polygons
+
+	... type q to quit and q to confirm the quit
+
+
+	ap> display dev$ypix 2 fi+ 
+
+	... redisplay the image
+
+	ap> polymark dev$ypix coords="" polygons=ypix.ver.1 \
+	    display=imdg
+
+	... type l to mark the polygon list, note that since there is
+	    no coords file the polygons are not shifted
+
+	... type q to quit and q to confirm the quit
+.fi
+
+
+2. Repeat the previous example using an image section.
+
+.nf
+	ap> display dev$ypix[150:450,150:450] 1 fi+ 
+
+	... display the image
+
+
+	ap> polymark dev$ypix[150:450,150:450]] display=imdg wcsout=tv
+
+	... type ? for an optional help page 
+
+	... type g to enter the "define a polygon" menu
+	... move the cursor to the first vertex, tap the space bar
+	    to mark the vertex, and repeat for each vertex
+	... type q to quit the "define a polygon" menu
+	... mark each vertex only once, POLYPHOT will close the
+	    polygon for you
+
+	... move the cursor to the desired polygon center and
+	    tap the space bar to record the polygon
+	... repeat for all desired polygon centers
+
+	... type g to define the next polygon
+	... move the cursor to the first vertex, tap the space bar
+	    to mark the vertex and repeat for each vertex
+	... type q to quit the polygon menu
+	... mark each vertex only once, POLYPHOT will close the
+	    polygon for you
+
+	... move the cursor to the desired polygon center and
+	    tap the space bar
+	... repeat for all desired polygon centers
+
+	... type q to quit and q to confirm the quit
+
+	... output will appear in ypix.coo.2 and ypix.ver.2
+
+
+	ap> display dev$ypix[150:450,150:450] 2 fi+ 
+
+	... display the image
+
+
+	ap> polymark dev$ypix[150:450,150:450] coords=ypix.coo.2 \
+            polygons=ypix.ver.2 display=imdg wcsin=tv
+
+	... type m to mark the first polygon / polygon center on the display
+
+	... type m to mark the next polygon / polygon center on the display
+
+	... type l to mark the remaining polygons
+
+.fi
+
+
+3. Repeat example 1 using a contour plot instead of the image display.
+
+.nf
+	ap> show stdimcur
+
+	... record the default value of stdimcur
+
+	ap> set stdimcur = stdgraph
+
+	... define the image cursor to be the graphics cursor
+
+	ap> contour dev$ypix
+
+	... draw a contour plot on the screen
+
+	ap> contour dev$ypix >G ypix.plot1
+
+	... store the contour plot of dev$ypix in the file ypix.plot1
+
+	ap> polymark dev$ypix display=stdgraph
+
+	... type g to enter the define a polygon menu
+	... move the cursor to the first vertex, tap the space bar
+	    to mark the vertex, and repeat for each vertex
+	... type q to quit the define a polygon menu
+	... mark each vertex only once, POLYPHOT will close the
+	    polygon for you
+
+	... move the cursor to the desired polygon center and
+	    tap the space bar to record the polygon
+	... repeat for all desired polygon centers
+
+	... type g to define the next polygon
+	... move the cursor to the first vertex, tap the space bar
+	    to mark the vertex and repeat for each vertex
+	... type q to quit the define a polygon menu
+	... mark each vertex only once, POLYPHOT will close the
+	    polygon for you
+
+	... move the cursor to the desired polygon center and
+	    tap the space bar
+	... repeat for all desired polygon centers
+
+	... type r to rewind the coordinate and polygon lists
+
+	... type :.read ypix.plot1 to reread the contour plot
+
+	... type l to display all the polygons ...
+
+	... type q to quit and q again to confirm the  quit
+
+	... output will appear in ypix.ver.3 and ypix.coo.3
+
+	ap> contour dev$ypix
+
+	... redraw the contour plot
+
+	ap> polymark dev$ypix coords="ypix.coo.3" polygons=ypix.ver.3 \
+	    display=stdgraph
+
+	ap> set stdimcur = <default>
+
+	... reset the value of the stdimcur parameter
+.fi
+
+.ih
+BUGS
+
+It is the responsibility of the user to make sure that the image displayed
+in the image display is the same as the image specified by the image parameter.
+
+Commands which draw to the image display are disabled by default.  To enable
+graphics overlay on the image display, set the display parameter to "imdr",
+"imdg", "imdb", or "imdy" to get red, green, blue or yellow overlays. It
+may be necessary to run gflush and to redisplay the image to get the overlays
+position correctly.
+
+There are no restrictions on the shape of the polygon but the vertices
+must be listed in order either clockwise or counterclockwise in the
+polygons file.
+
+It is not necessary to close the polygon when drawing on the display.
+POLYMARK will complete the polygon for you.
+
+.ih
+SEE ALSO
+polyphot
+.endhelp
diff --git a/noao/digiphot/apphot/doc/polypars.hlp b/noao/digiphot/apphot/doc/polypars.hlp
new file mode 100644
index 00000000..e31e4dcd
--- /dev/null
+++ b/noao/digiphot/apphot/doc/polypars.hlp
@@ -0,0 +1,69 @@
+.help polypars May00 noao.digiphot.apphot
+.ih
+NAME
+polypars -- edit the polygonal aperture photometry parameters
+.ih
+USAGE
+polypars
+.ih
+PARAMETERS
+.ls zmag = 25.00
+The zero point offset for the magnitude scale.
+.le
+.ls mkpolygon = no
+Draw the polygons on the screen.
+.le
+.ih
+DESCRIPTION
+The zero point of the magnitude scale is determined by \fIzmag\fR.
+
+If the \fImkpolygon\fR switch is enabled polygons are marked on the screen.
+.ih
+EXAMPLES
+
+1. List the polygonal aperture photometry parameters.
+
+.nf
+	ap> lpar polypars
+.fi
+
+2. Edit the polygonal aperture photometry parameters.
+
+.nf
+	ap> polypars
+.fi
+
+3. Edit the POLYPARS parameters from within the POLYPHOT task.
+
+.nf
+    da> epar polyphot
+
+	... edit a few polyphot parameters
+
+	... move to the polypars parameter and type :e
+
+	... edit the polypars parameters and type :wq
+
+	... finish editing the polyphot parameters and type :wq
+.fi
+
+4. Save the current POLYPARS parameter set in a text file polynite1.par.
+This can also be done from inside a higher level task as in the
+above example.
+
+.nf
+    da> polypars
+
+	... edit some parameters
+
+	... type ":w polynite1.par"  from within epar
+
+.fi
+.ih
+TIME REQUIREMENTS
+.ih
+BUGS
+.ih
+SEE ALSO
+polyphot. polymark
+.endhelp
diff --git a/noao/digiphot/apphot/doc/polyphot.hlp b/noao/digiphot/apphot/doc/polyphot.hlp
new file mode 100644
index 00000000..8bec19d4
--- /dev/null
+++ b/noao/digiphot/apphot/doc/polyphot.hlp
@@ -0,0 +1,791 @@
+.help polyphot May00 noao.digiphot.apphot
+.ih
+NAME
+polyphot -- compute magnitudes inside polygonal apertures
+.ih
+USAGE
+polyphot image
+.ih
+PARAMETERS
+.ls image
+The list of images containing the objects to be measured.
+.le
+.ls coords = ""
+The list of text files containing the center coordinates of the polygons
+to be measured. Polygon centers are listed one per line with the x and y
+coordinates in columns one and two. A ";" character in column terminates
+the polygon center list for the current polygon and tells POLYPHOT to skip
+to the next polygon listed in \fIpolygons\fR.  If coords is undefined the
+polygons are not shifted. The number of polygon center files must be
+zero, one, or equal to the number of images. If coords is "default",
+"dir$default", or a directory specification then a coords file name
+of the form dir$root.extension.version is constructed and searched for,
+where dir is the directory, root is the root image name, extension is "coo"
+and version is the next available version number for the file.
+.le
+.ls polygons = ""
+The list of text files containing the vertices of the polygons to be
+measured.  The polygon vertices are listed 1 vertext per line with the x and y
+coordinates of each vertex in columns 1 and 2. The vertices list is terminated
+a ';' in column 1. The number of polygon files must be zero, one, or
+equal to the number of images.  If polygons is "default", "dir$default", or
+a directory specification then a coords file name of the form
+dir$root.extension.version is constructed and searched for, where dir is the
+directory, root is the root image name, extension is "ver"
+and version is the next available version number for the file.
+.le
+.ls output = "default"
+The name of the results file or results directory. If output is
+"default", "dir$default", or a directory specification then an output file name
+of the form dir$root.extension.version is constructed, where dir is the
+directory, root is the root image name, extension is "ply" and version is
+the next available version number for the file. The number of output files
+must be zero, one, or equal to the number of image files.  In both interactive
+and batch mode full output is written to output. In interactive mode
+an output summary is also written to the standard output.
+.le
+.ls datapars = ""
+The name of the file containing the data dependent parameters. The critical
+parameters \fIfwhmpsf\fR and \fIsigma\fR are located here. If \fIdatapars\fR
+is undefined then the default parameter set in uparm directory is used.
+.le
+.ls centerpars = ""
+The name of the file containing the centering parameters. The critical
+parameters \fIcalgorithm\fR and \fIcbox\fR are located here.
+If \fIcenterpars\fR is undefined then the default parameter set in
+uparm directory is used.
+.le
+.ls fitskypars = ""
+The name of the text file containing the sky fitting parameters. The critical
+parameters \fIsalgorithm\fR, \fIannulus\fR, and \fIdannulus\fR are located here.
+If \fIfitskypars\fR is undefined then the default parameter set in uparm
+directory is used.
+.le
+.ls polypars = ""
+The name of the text file containing the polygon photometry parameters,
+If \fIpolypars\fR is undefined then the default parameter set in 
+ uparm directory is used.
+.le
+.ls interactive = yes
+Run the task interactively ?
+.le
+.ls icommands = ""
+The image cursor or image cursor command file.
+.le
+.ls gcommands = ""
+The graphics cursor or graphics cursor command file.
+.le
+.ls wcsin = ")_.wcsin", wcsout = ")_.wcsout"
+The coordinate system of the input coordinates read from \fIcoords\fR and
+of the output coordinates written to \fIoutput\fR respectively. The image
+header coordinate system is used to transform from the input coordinate
+system to the "logical" pixel coordinate system used internally,
+and from the internal "logical" pixel coordinate system to the output
+coordinate system. The input coordinate system options are "logical", tv",
+"physical", and "world". The output coordinate system options are "logical",
+"tv", and "physical". The image cursor coordinate system is assumed to
+be the "tv" system.
+.ls logical
+Logical coordinates are pixel coordinates relative to the current image.
+The  logical coordinate system is the coordinate system used by the image
+input/output routines to access the image data on disk. In the logical
+coordinate system the coordinates of the first pixel of a  2D image, e.g.
+dev$ypix  and a 2D image section, e.g. dev$ypix[200:300,200:300] are
+always (1,1).
+.le
+.ls tv
+Tv coordinates are the pixel coordinates used by the display servers. Tv
+coordinates  include  the effects of any input image section, but do not
+include the effects of previous linear transformations. If the input
+image name does not include an image section, then tv coordinates are
+identical to logical coordinates.  If the input image name does include a
+section, and the input image has not been linearly transformed or copied from
+a parent image, tv coordinates are identical to physical coordinates.
+In the tv coordinate system the coordinates of the first pixel of a
+2D image, e.g. dev$ypix and a 2D image section, e.g. dev$ypix[200:300,200:300]
+are (1,1) and (200,200) respectively.
+.le
+.ls physical
+Physical coordinates are pixel coordinates invariant  with respect to linear
+transformations of the physical image data.  For example, if the current image
+was created by extracting a section of another image,  the  physical
+coordinates of an object in the current image will be equal to the physical
+coordinates of the same object in the parent image,  although the logical
+coordinates will be different.  In the physical coordinate system the
+coordinates of the first pixel of a 2D image, e.g. dev$ypix and a 2D
+image section, e.g. dev$ypix[200:300,200:300] are (1,1) and (200,200)
+respectively.
+.le
+.ls world
+World coordinates are image coordinates in any units which are invariant
+with respect to linear transformations of the physical image data. For
+example, the ra and dec of an object will always be the same no matter
+how the image is linearly transformed. The units of input world coordinates
+must be the same as those expected by the image header wcs, e. g.
+degrees and degrees for celestial coordinate systems.
+.le
+The wcsin and wcsout parameters default to the values of the package
+parameters of the same name. The default values of the package parameters
+wcsin and wcsout are "logical" and "logical" respectively.
+.le
+.le
+.ls cache = ")_.cache"
+Cache the image pixels in memory. Cache may be set to the value of the apphot
+package parameter (the default), "yes", or "no". By default cacheing is 
+disabled.
+.le
+.ls verify = ")_.verify"
+Verify the critical parameters in non-interactive mode ? Verify may be set to
+the apphot package parameter value (the default), "yes", or "no.
+.le
+.ls update = ")_.update"
+Update the critical parameters in non-interactive mode if verify is yes ?
+Update may be set to the apphot package parameter value (the default), "yes",
+or "no.
+.le
+.ls verbose = ")_.verbose"
+Print messages in non-interactive mode? Verbose may be set to the apphot
+package parameter value (the default), "yes", or "no.
+.le
+.ls graphics = ")_.graphics"
+The default graphics device. Graphics may be set to the apphot package
+parameter value (the default), "yes",
+or "no.
+.le
+.ls display = ")_.display"
+The default display device. By default graphics overlay is disabled. Display
+may be set to the apphot package parameter value (the default), "yes", or "no. 
+Setting display to one of "imdr", "imdg", "imdb", or "imdy" enables graphics
+overlay with the IMD graphics kernel.  Setting display to "stdgraph" enables
+POLYPHOT to work interactively from a contour plot.
+.le
+
+.ih
+DESCRIPTION
+
+POLYPHOT computes the magnitude of objects in the IRAF image \fIimage\fR
+inside a list of polygonal apertures whose vertices are listed in the text file
+\fIpolygons\fR or are marked on the display interactively with the
+image cursor. The polygon centers  may be read from the polygon center
+file \fIcoords\fR or set interactively with the image cursor.
+
+The coordinates read from \fIcoords\fR are assumed to be in coordinate
+system defined by \fIwcsin\fR. The options are "logical", "tv", "physical",
+and "world" and the transformation from the input coordinate system to
+the internal "logical" system is defined by the image coordinate system.
+The simplest default is the "logical" pixel system. Users working on with
+image sections but importing pixel coordinate lists generated from the parent
+image must use the "tv" or "physical" input coordinate systems.
+Users importing coordinate lists in world coordinates, e.g. ra and dec,
+must use the "world" coordinate system and may need to convert their
+equatorial coordinate units from hours and degrees to degrees and degrees first.
+
+The coordinates written to \fIoutput\fR are in the coordinate
+system defined by \fIwcsout\fR. The options are "logical", "tv",
+and "physical". The simplest default is the "logical" system. Users
+wishing to correlate the output coordinates of objects measured in
+image sections or mosaic pieces with coordinates in the parent
+image must use the "tv" or "physical" coordinate systems.
+
+If \fIcache\fR is yes and the host machine physical memory and working set size
+are large enough, the input image pixels are cached in memory. If cacheing
+is enabled and POLYPHOT is run interactively the first measurement will appear
+to take a long time as the entire image must be read in before the measurement
+is actually made. All subsequent measurements will be very fast because POLYPHOT
+is accessing memory not disk. The point of cacheing is to speed up random
+image access by making the internal image i/o buffers the same size as the
+image itself. However if the input object lists are sorted in row order and
+sparse cacheing may actually worsen not improve the execution time. Also at
+present there is no point in enabling cacheing for images that are less than
+or equal to 524288 bytes, i.e. the size of the test image dev$ypix, as the
+default image i/o buffer is exactly that size. However if the size of dev$ypix
+is doubled by converting it to a real image with the chpixtype task then the
+effect of cacheing in interactive is can be quite noticeable if measurements
+of objects in the top and bottom halfs of the image are alternated.
+
+In interactive mode the user may either define the list of objects to be
+measured interactively with the image cursor or create a polygon and polygon
+center list prior to running POLYPHOT. In either case the user may adjust
+the centering, sky fitting, and photometry algorithm parameters until a
+satisfactory fit is achieved and optionally store the final results
+in \fIoutput\fR. In batch mode the polygon and polygon centers are read
+from the text files \fIpolygons\fR and \fIcoords\fR or the image cursor
+parameter \fIicommands\fR can be redirected to a text file containing
+a list of cursor commands. In batch mode the current set of algorithm
+parameters is used.
+
+.ih
+THE POLYGON and POLYGON CENTERS FILES
+
+A sample polygons file and accompanying coordinates file is listed below.
+
+.nf
+        # Sample Polygons File (2 polygons)
+
+        200.5  200.5
+        300.5  200.5
+        300.5  300.5
+        200.5  300.5
+        ;
+        100.4  100.4
+        120.4  100.4
+        120.4  120.4
+        100.4  120.4
+        ;
+.fi
+
+.nf
+        # Sample Coordinates File (2 groups, 1 for each polygon)
+
+        123.4  185.5
+        110.4  130.4
+        150.9  200.5
+        ;
+        85.6   35.7
+        400.5  300.5
+        69.5   130.5
+        ;
+.fi
+
+
+.ih
+CURSOR COMMANDS
+
+The following polyphot commands are currently available.
+
+.nf
+	Interactive Keystroke Commands
+
+?	Print help
+:	Colon commands
+v	Verify the critical parameters
+w	Store the current parameters
+d	Plot radial profile of current object
+i	Define current polygon, graphically set parameters using current object
+g	Define current polygon 
+c	Fit center for current object
+t	Fit sky around cursor
+a       Average sky values fit around several cursor positions
+s	Fit sky around current object
+h	Do photometry for current polygon
+j	Do photometry for current polygon, output results
+p	Do photometry for current object using current sky
+o	Do photometry for current object using current sky, output results
+f	Do photometry for current object
+spbar	Do photometry for current object, output results
+m	Move to next object in coordinate list
+n	Do photometry for next object in coordinate list, output results
+l	Do photometry for remaining objects in list, output results
+r	Rewind the polygon list
+e	Print error messages
+q	Exit task
+
+
+	Colon Commands
+
+:show	[data/center/sky/phot]	List the parameters
+:m [n]	Move to next [nth] object in coordinate list
+:n [n]	Do photometry for next [nth] object in coordinate list, output results
+
+
+	Colon Parameter Editing Commands
+
+# Image and file name parameters
+
+:image		[string]	Image name
+:polygon	[string]	Polygon file
+:coords		[string]	Coordinate file
+:output		[string]	Results file
+
+# Data dependent parameters
+
+:scale		[value]		Image scale (units per pixel)
+:fwhmpsf	[value]		Full-width half-maximum of PSF (scale units)
+:emission	[y/n]		Emission feature (y), absorption (n)
+:sigma		[value]		Standard deviation of sky (counts)
+:datamin	[value]		Minimum good pixel value (counts)
+:datamax	[value]		Maximum good pixel value (counts)
+
+# Noise parameters
+
+:noise		[string]	Noise model (constant|poisson)
+:gain		[string]	Gain image header keyword
+:ccdread	[string]	Readout noise image header keyword
+:epadu		[value]		Gain (electrons per count)
+:epadu		[value]		Readout noise (electrons)
+
+# Observing parameters
+
+:exposure	[string]	Exposure time image header keyword
+:airmass	[string]	Airmass image header keyword
+:filter		[string]	Filter image header keyword
+:obstime	[string]	Time of observation image header keyword
+:itime		[value]		Integration time (time units)
+:xairmass	[value]		Airmass value (number)
+:ifilter	[string]	Filter id string
+:otime		[string]	Time of observation (time units)
+
+# Centering algorithm parameters
+
+:calgorithm	[string]	Centering algorithm
+:cbox		[value]		Width of centering box (scale units)
+:cthreshold	[value]		Centering intensity threshold (sigma)
+:cmaxiter	[value]		Maximum number of iterations
+:maxshift	[value]		Maximum center shift (scale units)
+:minsnratio	[value]		Minimum S/N ratio for centering
+:clean		[y/n]		Clean subraster before centering
+:rclean		[value]		Cleaning radius (scale units)
+:rclip		[value]		Clipping radius (scale units)
+:kclean		[value]		Clean K-sigma rejection limit (sigma)
+
+# Sky fitting algorithm parameters
+
+:salgorithm	[string]	Sky fitting algorithm 
+:skyvalue	[value]		User supplied sky value (counts)
+:annulus	[value]		Inner radius of sky annulus (scale units)
+:dannulus	[value]		Width of sky annulus (scale units)
+:khist		[value]		Sky histogram extent (+/- sigma)
+:binsize	[value]		Resolution of sky histogram (sigma)
+:sloclip	[value]		Low-side clipping factor in percent
+:shiclip	[value]		High-side clipping factor in percent
+:smooth		[y/n]		Lucy smooth the sky histogram
+:smaxiter	[value]		Maximum number of iterations
+:snreject	[value]		Maximum number of rejection cycles
+:sloreject	[value]		Low-side pixel rejection limits (sky sigma)
+:shireject	[value]		High-side pixel rejection limits (sky sigma)
+:rgrow		[value]		Region growing radius (scale units)
+
+# Photometry parameters
+
+:zmag		[value]		Zero point of magnitude scale
+
+# Plotting and marking parameters
+
+:mkcenter	[y/n]		Mark computed centers on the display
+:mksky		[y/n]		Mark the sky annuli on the display
+:mkpolygon	[y/n]		Mark the polygon on the display
+
+
+
+The following commands are available from inside the interactive setup menu.
+
+
+                    Interactive Photometry Setup Menu
+
+	v	Mark and verify the critical parameters (f,c,s,a,d)
+
+	f	Mark and verify the psf full-width half-maximum
+	s	Mark and verify the standard deviation of the background
+	l	Mark and verify the minimum good data value
+	u	Mark and verify the maximum good data value
+
+	c	Mark and verify the centering box width
+	n	Mark and verify the cleaning radius
+	p	Mark and verify the clipping radius
+
+	a	Mark and verify the inner radius of the sky annulus
+	d	Mark and verify the width of the sky annulus
+	g	Mark and verify the region growing radius
+.fi
+
+.ih
+ALGORITHMS
+
+A brief description of the data dependent parameters, the centering
+algorithms and the sky fitting algorithms can be found in the online
+manual pages for the DATAPARS, CENTERPARS, and FITSKYPARS tasks.
+User measuring extended "fuzzy" features may wish to set the CENTERPARS 
+\fIcalgorithm\fR parameter to "none", the FITSKYPARS parameters
+\fIsalgorithm\fR and \fIskyvalue\fR to "constant" and <uservalue> before
+running POLYPHOT.
+
+POLYPHOT computes the intersection of each image line with the line segments
+composing the polygon in order to determine the extent of the polygon. A one
+dimensional summation including a fractional approximation for the end pixels
+is performed over those regions of the image line which intersect the polygon.
+All the 1D summations are summed to give the total integral. The vertices of
+the polygon must be specified in order either clockwise or counterclockwise.
+
+.ih
+OUTPUT
+
+In interactive mode the following quantities are printed on the standard
+output as each object is measured. Error is a simple string which indicates
+whether the task encountered an error in the centering algorithm, the sky
+fitting algorithm or the photometry algorithm. Mag are the magnitudes in
+the polygonal aperture and xcenter, ycenter and msky are the x and y centers
+and the sky value respectively.
+
+.nf
+    image  xcenter  ycenter  msky  mag  merr error
+.fi
+
+In both interactive and batch mode full output is written to the text file
+\fIoutput\fR. At the beginning of each file is a header listing the current
+values of the parameters when the first stellar record was written.  These
+parameters can be subsequently altered. For each star measured the following
+record is written
+
+.nf
+	image  xinit  yinit  id  coords  lid
+	   xcenter  ycenter  xshift  yshift  xerr  yerr  cier error
+	   msky  stdev  sskew  nsky  nsrej  sier  serror
+	   itime  xairmass  ifilter  otime
+	   sum  area  flux mag  merr  pier  perr
+	   polygons  pid  oldxmean  oldymean  xmean  ymean  maxrad  nver
+	   xvertex  yvertex
+.fi
+
+Image and coords are the name of the image and coordinate file respectively.
+Id and lid are the sequence numbers of objects in the output and coordinate
+files respectively. Cier and cerror are the centering error code and
+accompanying error message respectively.  Xinit, yinit, xcenter, ycenter,
+xshift, yshift, and xerr, yerr are self explanatory and output in pixel units.
+The sense of the xshift and yshift definitions is the following.
+
+.nf
+	xshift = xcenter - xinit
+	yshift = ycenter - yinit
+.fi
+
+Sier and serror are the sky fitting error code and accompanying error
+message respectively.  Msky, stdev and sskew are the best estimate of the
+sky value (per pixel), standard deviation and skew respectively. Nsky and
+nsrej are the number of sky pixels used and the number of sky pixels rejected
+from the fit respectively.
+
+Itime is the exposure time, xairmass is self-evident, ifilter is an id string
+identifying the filter used during the observation, and otime is a string
+specifying the time of the observation in whatever units the user has chosen.
+
+Sum, area, and flux are the total number of counts including sky in the
+polygonal aperture, the area of the aperture in square pixels, and the total
+number of counts in the aperture excluding sky. Mag and merr are the magnitude
+and error in the magnitude in the aperture after subtracting the sky value
+(see below).
+
+.nf
+        flux = sum - area * msky
+         mag = zmag - 2.5 * log10 (flux) + 2.5 * log10 (itime)
+        merr = 1.0857 * error / flux
+       error = sqrt (flux / epadu + area * stdev**2 +
+               area**2 * stdev**2 / nsky)
+.fi
+
+Pier and perror are photometry error code and accompanying error message.
+
+Polygons and pid are the name of the polygons file and the polygon id
+respectively. Oldxmean, oldymean, xmean and ymean are the original and
+current average coordinates of the current polygon. Oldxmean and oldymean
+are the values in the polygons file or the values which correspond to the
+polygon drawn on the display. Xinit and yinit define the position to
+which the polygonal aperture was shifted. Xmean and ymean are generally
+identical to xcenter and ycenter and describe the position of the
+centered polygonal aperture. Maxrad is the maximum
+distance of a polygon vertex from the average of the vertices. Nver, xvertex
+and yvertex are the number of vertices and the coordinates of the vertices
+of the polygonal aperture.
+
+.ih
+ERRORS
+
+If the object centering was error free then the field cier will be zero.
+Non-zero values of cier flag the following error conditions.
+
+.nf
+	0        # No error
+	101      # The centering box is off image
+	102      # The centering box is partially off the image
+	103      # The S/N ratio is low in the centering box
+	104      # There are two few points for a good fit
+	105      # The x or y center fit is singular
+	106      # The x or y center fit did not converge
+	107      # The x or y center shift is greater than maxshift
+	108      # There is bad data in the centering box
+.fi
+
+If all goes well during the sky fitting process then the error code sier
+will be 0. Non-zero values of sier flag the following error conditions.
+
+.nf
+	0         # No error
+	201       # There are no sky pixels in the sky annulus
+	202       # Sky annulus is partially off the image
+	203       # The histogram of sky pixels has no width
+	204       # The histogram of sky pixels is flat or concave
+	205       # There are too few points for a good sky fit
+	206       # The sky fit is singular
+	207       # The sky fit did not converge
+	208       # The graphics stream is undefined
+	209       # The file of sky values does not exist
+	210       # The sky file is at EOF
+	211       # Cannot read the sky value correctly
+	212       # The best fit parameter are non-physical
+.fi
+
+If no error occurs during the measurement of the magnitudes then pier is
+0. Non-zero values of pier flag the following error conditions.
+
+.nf
+	0       # No error
+	801	# The polygon is undefined
+	802     # The polygon is partially off the image
+	803     # The polygon is off the image
+	804     # The sky value is undefined
+	805     # There is bad data in the aperture
+.fi
+
+.ih
+EXAMPLES
+
+1. Compute the magnitudes inside  2 polygonal aperture for a few  regions in
+dev$ypix using the display and the image cursor.  Turn off centering and set
+the sky background to 0.0.
+
+.nf
+	ap> display dev$ypix 1 fi+
+
+	... display the image
+
+	ap> polyphot dev$ypix calgorithm=none salgorithm=constant \
+            skyvalue=0.0 display=imdg mkpolygon+
+
+	... type ? to print a help page
+
+	... move image cursor to a region of interest
+
+	... type g to enter the polygon definition menu
+	... use the image cursor and spbar key to mark the vertices of
+            the polygonal aperture 
+	... mark each vertex only once, POLYPHOT will close the polygon
+	    for you
+        ... type q to quit the polygon definition menu
+
+	... type the v key to verify the parameters
+
+	... type the w key to save the parameters in the parameter files
+
+	... move the image cursor to the objects of interest and tap
+	    the space bar, the polygon will be marked on the image 
+            display
+
+	... type g to enter the polygon definition menu
+	... use the image cursor and spbar key to mark the vertices of
+            the polygonal aperture 
+	... mark each vertex only once, POLYPHOT will close the polygon
+	    for you
+        ... type q to quit the polygon definition menu
+
+	... move the image cursor to the objects of interest and tap
+	    the space bar, the polygon will be marked on the image
+            display 
+
+	... a one line summary of the fitted parameters will appear on the
+	    standard output for each star measured
+
+	... the output will appear in ypix.ply.1
+.fi
+
+
+2.  Repeat the previous example but use a contour plot and the graphics
+cursor in place of the image display and image cursor. This option is
+really only useful for users (very few these days) with access to a graphics
+terminal but not an image display server.
+
+.nf
+	ap> show stdimcur
+
+        ... determine the default value of stdimcur
+
+	ap> set stdimcur = stdgraph
+
+	... define the image cursor to be the graphics cursor
+
+        ap> contour dev$ypix
+
+        ... create a contour plot of dev$ypix
+
+	ap> contour dev$ypix >G ypix.plot1
+
+	... store the contour plot of dev$ypix in the file ypix.plot1
+
+	ap> polyphot dev$ypix calgorithm=none salgorithm=constant \
+            skyvalue=0.0 display=stdgraph mkpolygon+
+
+	... type ? to print a help page
+
+	... type the v key to verify the parameters
+
+	... type the w key to save the parameters in the parameter files
+
+	... move image cursor to a region of interest
+	... type g to enter the polygon definition menu
+	... use the image cursor and spbar key to mark the vertices of
+            the polygonal aperture 
+	... mark each vertex only once, POLYPHOT will close the polygon
+	    for you
+        ... type q to quit the polygon definition menu
+
+	... move the image cursor to the objects of interest and tap
+	    the space bar, the polygon will be marked on the contour
+            plot
+
+	... move image cursor to a region of interest
+	... type g to enter the polygon definition menu
+	... use the image cursor and spbar key to mark the vertices of
+            the polygonal aperture 
+	... mark each vertex only once, POLYPHOT will close the polygon
+	    for you
+        ... type q to quit the polygon definition menu
+
+	... move the image cursor to the objects of interest and tap
+	    the space bar, the polygon will be marked on the image 
+            display
+
+	... a one line summary of the fitted parameters will appear on the
+	    standard output for each star measured and the polygons will
+	    be drawn on the display
+
+	... full output will appear in the text file ypix.ply.2 
+
+	ap> reset stdimcur = <default>
+
+	... reset stdimcur to its default value
+
+
+.fi
+
+3. Setup and run POLYPHOT interactively on a list of objects created with
+POLYMARK.
+
+.nf
+	ap> display dev$ypix 1
+
+        ... display the image
+
+	ap> polymark dev$ypix display=imdg
+
+	... type g to enter the polygon definition menu
+        ... mark each vertex with the spbar
+	... mark each vertex only once, POLYPHOT will close the
+	    polygon for you
+        ... type q to quit the polygon definition menu 
+
+	... move the cursor to the regions of interest and tap
+	    the space bar, the polygon will be marked on the image
+            display
+
+	... the polygon and polygon centers will be written to the text
+            files ypix.ver.1 and ypix.coo.1 respectively
+
+	... type q to quit and q again to confirm the quit
+
+	ap> display dev$ypix 2
+
+        ... redisplay the image
+
+	ap> polyphot dev$ypix calgorithm=none salgorithm=constant skyvalue=0.0 \
+            coords=default polygon=default display=imdg mkpolygon+
+
+	... type n to measure the first polygon in the list
+
+	... if everything looks okay type l to measure the rest of the stars 
+
+	... a one line summary of results will appear on the standard output
+	    for each star measured and the aperture will be drawn on the
+            image display
+
+        ... type q to quit and q again to confirm the quit
+
+	... the output will appear in ypix.ply.3
+.fi
+
+
+4. Repeat example 3 but work on a section of the input image while
+preserving the coordinate system of the original image.
+
+.nf
+	ap> display dev$ypix[150:450,150:450] 1
+
+        ... display the image
+
+	p> polymark dev$ypix[150:450,150:450] wcsout=tv display=imdg
+
+	... type g to enter the polygon definition menu
+        ... mark each vertex with the spbar
+	... mark each vertex only once, POLYPHOT will close the
+	    polygon for you
+        ... type q to quit the polygon definition menu 
+
+	... move the cursor to the regions of interest and tap
+	    the space bar, the polygon will be marked on the image
+            display
+
+	... the polygon and polygon centers will be written to the text
+            files ypix.ver.1 and ypix.coo.1 respectively
+
+	... type q to quit and q again to confirm the quit
+
+	ap> display dev$ypix[150:450,150:450] 2
+
+        ... redisplay the image
+
+	ap> polyphot dev$ypix[150:450,150:450] calgorithm=none \
+	    salgorithm=constant skyvalue=0.0 coords=default polygon=default \
+	    display=imdg mkpolygon+ wcsin=tv wcsout=tv
+
+	... type n to measure the first polygon in the list
+
+	... if everything looks okay type l to measure the rest of the stars 
+
+	... a one line summary of results will appear on the standard output
+	    for each star measured and the aperture will be drawn on the
+            image display
+
+        ... type q to quit and q again to confirm the quit
+
+	... the output will appear in ypix.ply.4
+
+        ap> pdump ypix.ply.4 xc,yc yes | tvmark 2 STDIN col=204
+
+        ... mark the centers of the polygons on the display
+.fi
+
+
+5. Run POLYPHOT in batch mode using a polygon and coordinate file and the
+default parameters. Verify the critical parameters.
+
+.nf
+	ap> polyphot dev$ypix coords=default polygon=default inter- verify+
+
+	... output will appear in ypix.ply.5
+.fi
+
+
+.ih
+TIMINGS
+.ih
+BUGS
+There are no restrictions on the shape of the polygon but the vertices
+must be listed or marked in order.
+
+When marking the polygon on the display it is not necessary to close
+the polygon. When the user types q to quit the marking the program
+will automatically close the polygon.
+
+It is currently the responsibility of the user to make sure that the
+image displayed on the display is the same as that specified by the image
+parameter.
+
+Commands which draw to the image display are disabled by default.
+To enable graphics overlay on the image display, set the display
+parameter to "imdr", "imdg", "imdb", or "imdy" to get red, green,
+blue or yellow overlays and set the centerpars mkcenter switch to
+"yes", the fitskypars mksky switch to"yes", or the polypars mkpolygon
+switch to "yes". It may be necessary to run gflush and to redisplay the image
+to get the overlays position correctly.
+
+.ih
+SEE ALSO
+datapars,centerpars,fitskypars,polypars,qphot,phot,wphot
+.endhelp
diff --git a/noao/digiphot/apphot/doc/qphot.hlp b/noao/digiphot/apphot/doc/qphot.hlp
new file mode 100644
index 00000000..42e3f5bf
--- /dev/null
+++ b/noao/digiphot/apphot/doc/qphot.hlp
@@ -0,0 +1,647 @@
+.help qphot May00 noao.digiphot.apphot
+.ih
+NAME
+qphot -- quick aperture photometer
+.ih
+USAGE
+qphot image cbox annulus dannulus apertures
+.ih
+PARAMETERS
+.ls image
+The list of images containing the objects to be measured.
+.le
+.ls cbox
+The width of the centering box in pixels.
+.le
+.ls annulus
+The inner radius of the sky annulus in pixels.
+.le
+.ls dannulus
+The width of the sky annulus in pixels.
+.le
+.ls apertures
+The list of aperture radii in pixels. Apertures is a string parameter 
+specifying either a single aperture radius e.g. "3.0", a list of aperture
+radii separated by commas e.g. "3.0,5.0,10.0", or a range of aperture radii
+e.g. "1.0:20.0:1.0".
+.le
+.ls coords = ""
+The list of text files containing initial coordinates for the objects to
+be measured. Objects are listed in coords one object per line with the
+initial coordinate values in columns one and two. The number of coordinate
+files must be zero, one, or equal to the number of images. If coords is
+"default", "dir$default", or a directory specification then a coords file name
+of the form dir$root.extension.version is constructed and searched for,
+where dir is the directory, root is the root image name, extension is "coo"
+and version is the next available version number for the file.
+.le
+.ls output = "default"
+The name of the results file or results directory. If output is
+"default", "dir$default", or a directory specification then an output file name
+of the form dir$root.extension.version is constructed, where dir is the
+directory, root is the root image name, extension is "mag" and version is
+the next available version number for the file. The number of output files
+must be zero, one, or equal to the number of image files.  In both interactive
+and batch mode full output is written to output. In interactive mode
+an output summary is also written to the standard output.
+.le
+.ls plotfile = ""
+The name of the file containing radial profile plots of the stars written
+to the output file. If plotfile is defined then a radial profile plot
+is written to plotfile every time a record is written to \fIoutput\fR.
+The user should be aware that this can be a time consuming operation.
+.le
+.ls zmag = 25.0
+The zero point of the magnitude scale.
+.le
+.ls exposure = ""
+The image header keyword containing the exposure time.
+.le
+.ls airmass = ""
+The image header keyword containing the airmass of the observation.
+.le
+.ls filter = ""
+The image header keyword containing the filter id of the observation.
+.le
+.ls obstime = ""
+The image header keyword containing the time of the observation.
+.le
+.ls epadu = 1.0
+The gain in photons per adu. Epadu is used to compute the magnitude errors.
+.le
+.ls interactive = yes
+Interactive or batch mode.
+.le
+.ls radplots = no
+If radplots is "yes" and QPHOT is run in interactive mode then a radial profile
+of each star is plotted on the screen after it is measured.
+.le
+.ls icommands = ""
+The image display cursor or image cursor command file.
+.le
+.ls gcommands = ""
+The graphics cursor or graphics cursor command file.
+.le
+.ls wcsin = ")_.wcsin", wcsout = ")_.wcsout"
+The coordinate system of the input coordinates read from \fIcoords\fR and
+of the output coordinates written to \fIoutput\fR respectively. The image
+header coordinate system is used to transform from the input coordinate
+system to the "logical" pixel coordinate system used internally,
+and from the internal "logical" pixel coordinate system to the output
+coordinate system. The input coordinate system options are "logical", tv",
+"physical", and "world". The output coordinate system options are "logical",
+"tv", and "physical". The image cursor coordinate system is assumed to
+be the "tv" system.
+.ls logical
+Logical coordinates are pixel coordinates relative to the current image.
+The  logical coordinate system is the coordinate system used by the image
+input/output routines to access the image data on disk. In the logical
+coordinate system the coordinates of the first pixel of a  2D image, e.g.
+dev$ypix  and a 2D image section, e.g. dev$ypix[200:300,200:300] are
+always (1,1).
+.le
+.ls tv
+Tv coordinates are the pixel coordinates used by the display servers. Tv
+coordinates  include  the effects of any input image section, but do not
+include the effects of previous linear transformations. If the input
+image name does not include an image section, then tv coordinates are
+identical to logical coordinates.  If the input image name does include a
+section, and the input image has not been linearly transformed or copied from
+a parent image, tv coordinates are identical to physical coordinates.
+In the tv coordinate system the coordinates of the first pixel of a
+2D image, e.g. dev$ypix and a 2D image section, e.g. dev$ypix[200:300,200:300]
+are (1,1) and (200,200) respectively.
+.le
+.ls physical
+Physical coordinates are pixel coordinates invariant  with respect to linear
+transformations of the physical image data.  For example, if the current image
+was created by extracting a section of another image,  the  physical
+coordinates of an object in the current image will be equal to the physical
+coordinates of the same object in the parent image,  although the logical
+coordinates will be different.  In the physical coordinate system the
+coordinates of the first pixel of a 2D image, e.g. dev$ypix and a 2D
+image section, e.g. dev$ypix[200:300,200:300] are (1,1) and (200,200)
+respectively.
+.le
+.ls world
+World coordinates are image coordinates in any units which are invariant
+with respect to linear transformations of the physical image data. For
+example, the ra and dec of an object will always be the same no matter
+how the image is linearly transformed. The units of input world coordinates
+must be the same as those expected by the image header wcs, e. g.
+degrees and degrees for celestial coordinate systems.
+.le
+The wcsin and wcsout parameters default to the values of the package
+parameters of the same name. The default values of the package parameters
+wcsin and wcsout are "logical" and "logical" respectively.
+.le
+.le
+.ls cache = ")_.cache"
+Cache the image pixels in memory. Cache may be set to the value of the apphot
+package parameter (the default), "yes", or "no". By default cacheing is 
+disabled.
+.le
+.ls verbose = ")_.verbose"
+Print messages in non-interactive mode ? Verbose may be set to the apphot
+package parameter value (the default), "yes", or "no.
+.le
+.ls graphics = ")_.graphics"
+The default graphics device.  Graphics may be set to the apphot package
+parameter value (the default), "yes", or "no.
+.le
+.ls display = ")_.display"
+The default display device. Display may be set to the apphot package parameter
+value (the default), "yes", or "no. By default graphics overlay is disabled.
+Setting display to one of "imdr", "imdg", "imdb", or "imdy" enables graphics
+overlay with the IMD graphics kernel.  Setting display to "stdgraph" enables
+QPHOT to work interactively from a contour plot.
+.le
+
+.ih
+DESCRIPTION
+QPHOT computes accurate centers, sky values, and magnitudes for a list of
+objects in the IRAF image \fIimage\fR whose initial coordinates are
+read from the image cursor or the coordinate file \fIcoords\fR,
+and writes the computed x and y coordinates, sky values, and
+magnitudes to the text file \fIoutput\fR.
+
+The coordinates read from \fIcoords\fR are assumed to be in coordinate
+system defined by \fIwcsin\fR. The options are "logical", "tv", "physical",
+and "world" and the transformation from the input coordinate system to
+the internal "logical" system is defined by the image coordinate system.
+The simplest default is the "logical" pixel system. Users working on with
+image sections but importing pixel coordinate lists generated from the parent
+image must use the "tv" or "physical" input coordinate systems.
+Users importing coordinate lists in world coordinates, e.g. ra and dec,
+must use the "world" coordinate system and may need to convert their
+equatorial coordinate units from hours and degrees to degrees and degrees first.
+
+The coordinates written to \fIoutput\fR are in the coordinate
+system defined by \fIwcsout\fR. The options are "logical", "tv",
+and "physical". The simplest default is the "logical" system. Users
+wishing to correlate the output coordinates of objects measured in
+image sections or mosaic pieces with coordinates in the parent
+image must use the "tv" or "physical" coordinate systems.
+
+In interactive mode the user measure objects interactively with the image
+cursor, or select them interactively from the coordinate list \fIcoords\fR.
+In batch mode the coordinates can be read directly from \fIcoords\fR, or from 
+the cursor command file specified by the parameter \fIicommands\fR.
+
+If \fIcache\fR is yes and the host machine physical memory and working set size
+are large enough, the input image pixels are cached in memory. If cacheing
+is enabled and QPHOT is run interactively the first measurement will appear
+to take a long time as the entire image must be read in before the measurement
+is actually made. All subsequent measurements will be very fast because QPHOT
+is accessing memory not disk. The point of cacheing is to speed up random
+image access by making the internal image i/o buffers the same size as the
+image itself. However if the input object lists are sorted in row order and
+sparse cacheing may actually worsen not improve the execution time. Also at
+present there is no point in enabling cacheing for images that are less than
+or equal to 524288 bytes, i.e. the size of the test image dev$ypix, as the
+default image i/o buffer is exactly that size. However if the size of dev$ypix
+is doubled by converting it to a real image with the chpixtype task then the
+effect of cacheing in interactive is can be quite noticeable if measurements
+of objects in the top and bottom halfs of the image are alternated.
+
+QPHOT computes accurate centers for each object using the centroid
+centering algorithm, pixels inside \fIcbox\fR and the default values of the
+\fIcenterpars\fR parameters.  Accurate sky values for each object are
+computed using the \fIcentroid\fR sky fitting algorithm with histogram
+smoothing turned on, pixels inside the sky annulus defined by \fIannulus\fR
+and \fIdannulus\fR, and the default values of the remaining sky fitting
+parameters as defined in the \fIfitskypars\fR parameter set. Magnitudes
+are computed using pixels inside the apertures defined by \fIapertures\fR.
+The user must set the gain \fIepadu\fR to ensure that the magnitude error
+estimates are correctly computed and \fIexposure\fR to normalize the computed
+magnitudes to an exposure time of 1 time unit. The zero point of the magnitude
+scale can be adjusted by setting \fIzmag\fR. \fIAirmass\fR, \fIfilter\fR,
+and \fIobstime\fR are book-keeping parameters. Setting  them to appropriate
+values will simplify future analysis and calibration steps.
+
+.ih
+CURSOR COMMANDS
+
+The following list of cursor commands are currently available.
+
+.nf
+	Interactive Photometry Commands
+
+?	Print help
+:	Colon commands
+w	Save the current parameters
+d	Plot radial profile of current star
+i	Interactively set parameters using current star
+c	Fit center of current star
+t	Fit sky around the cursor
+a       Average sky values fit around several cursor positions
+s	Fit sky for current centered star
+p	Do photometry for current star, using current sky
+o	Do photometry for current star, using current sky, output results
+f	Do photometry for current star
+spbar	Do photometry for current star, output results
+e	Print error messages
+m	Move to next star in coordinate list
+n	Do photometry for next star in coordinate list, output results
+l	Do photometry for remaining stars in coordinate list, output results
+r	Rewind the coordinate list
+q	Exit task
+
+
+	Colon Commands
+
+:show	List the parameters
+:m [n]	Move to next [nth] star in coordinate list
+:n [n]	Do photometry for next [nth] star in coordinate list, output results
+
+	Colon Parameter Editing Commands
+
+:image		[string]	Image name
+:output		[string]	Output file name
+:coords		[string]	Coords file name
+
+:cbox		[value]		Width of the centering box (pixels)
+:annulus	[value]		Inner radius of sky annulus (pixels)
+:dannulus	[value]		Width of sky annulus (pixels)
+:apertures	[string]	List of aperture radii (pixels)
+:zmag		[value]		Zero point of magnitude scale (magnitudes)
+:epadu		[value]		Gain (electrons  per adu)
+
+:exposure	[string]	Exposure time image header keyword
+:airmass	[string]	Airmass image header keyword
+:filter		[string]	Filter image header keyword
+:obstime	[string]	Time of observation image header keyword
+
+:radplot	[y/n]		Plot radial profile of object
+
+
+The following commands are available from inside the interactive setup menu
+using the i key.
+
+
+                    Interactive Qphot Setup Menu
+
+	v	Mark and verify the critical parameters (c,a,d,r)
+
+	c	Mark and verify the centering box width
+	a	Mark and verify the inner radius of the sky annulus
+	d	Mark and verify the width of the sky annulus
+	r	Mark and verify the aperture radii
+.fi
+
+.ih
+OUTPUT
+In interactive mode the following quantities are printed on the standard
+output as each object is measured. Error is a simple string which indicates
+whether the task encountered an error condition from
+the centering algorithm, the sky fitting algorithm or the photometry
+algorithm respectively. Mag are the magnitudes in
+apertures 1 through N respectively and xcenter, ycenter and msky are the
+x and y centers and the sky value respectively.
+
+.nf
+    image  xcenter  ycenter  msky  mag[1 ... N]  error
+.fi
+
+In both interactive and batch mode full output is written to the text file
+\fIoutput\fR. At the beginning of each file is a header listing the
+current values of the parameters when the first stellar record was written.
+These parameters can be subsequently altered. For each star measured the
+following record is written.
+
+.nf
+	image  xinit  yinit  id  coords  lid
+	   xcenter  ycenter  xshift  yshift  xerr  yerr  cier cerror
+	   msky  stdev  sskew  nsky  nsrej  sier  serror
+	   itime  xairmass  ifilter  otime
+	   rapert  sum  area  flux mag  merr  pier  perror
+.fi
+
+Image and coords are the name of the image and coordinate file respectively.
+Id and lid are the sequence numbers of stars in the output and coordinate
+files respectively. Cier and cerror are the error code and accompanying
+error message for the center computation.  Xinit, yinit, xcenter, ycenter,
+xshift, yshift, and xerr, yerr are self explanatory and output in pixel units.
+The sense of the xshift and yshift definitions is the following.
+
+.nf
+	xshift = xcenter - xinit
+	yshift = ycenter - yinit
+.fi
+
+Sier and serror are the sky fitting error code and accompanying error message
+respectively.  Msky, stdev and sskew are the best estimate of the sky value
+(per pixel), standard deviation and skew respectively. Nsky and nsrej are
+the number of sky pixels used and the number of sky pixels rejected
+respectively.
+
+Itime is the exposure time, xairmass is self-evident, ifilter is an
+id string used to identify the filter used during the observation, and
+otime is a string containing the time stamp in whatever units the
+user has written into the image header or the otime parameter.
+
+Rapert, sum, area, and flux  are the radius of the aperture in pixels, the
+total number of counts including sky in the aperture, the area of the aperture
+in square pixels, and the total number of counts in the aperture excluding
+sky. Mag and merr are the magnitude and error in the magnitude in the aperture.
+
+.nf
+	flux = sum - area * msky
+	 mag = zmag - 2.5 * log10 (flux) + 2.5 * log10 (itime)
+	merr = 1.0857 * err / flux
+	 err = sqrt (flux / epadu + area * stdev**2 +
+	       area**2 * stdev**2 / nsky)
+.fi
+
+Pier and perror are photometry error code and accompanying error message.
+
+In interactive mode a radial profile of each measured object is plotted
+in the graphics window if \fIradplots\fR is "yes".
+
+In interactive and batchmode a radial profile plot is written to
+\fIplotfile\fR  if it is defined each time the result of an object
+measurement is written to \fIoutput\fR .
+
+
+.ih
+ERRORS
+If the object centering was error free then the field cier will be zero.
+Non-zero values of cier flag the following error conditions.
+
+.nf
+0        # No error
+101      # The centering box is off image
+102      # The centering box is partially off the image
+103      # The S/N ratio is low in the centering box
+104      # There are two few points for a good fit
+105      # The x or y center fit is singular
+106      # The x or y center fit did not converge
+107      # The x or y center shift is greater than 1 pixel
+108      # There is bad data in the centering box
+
+.fi
+
+If all goes well during the sky fitting process then the error code sier
+will be 0. Non-zero values of sier flag the following error conditions.
+
+.nf
+0         # No error
+201       # There are no sky pixels in the sky annulus
+202       # Sky annulus is partially off the image
+203	  # The histogram of sky pixels has no width
+204	  # The histogram of sky pixels is flat or concave
+205       # There are too few points for a good sky fit
+206       # The sky fit is singular
+207       # The sky fit did not converge
+208       # The graphics stream is undefined
+209       # The file of sky values does not exist
+210       # The sky file is at EOF
+211       # Cannot read the sky value correctly
+212       # The best fit parameter are non-physical
+
+.fi
+
+If no error occurs during the measurement of the magnitudes then pier is
+0. Non-zero values of pier flag the following error conditions.
+
+.nf
+0        # No error
+301      # The aperture is off the image
+302      # The aperture is partially off the image
+303      # The sky value is undefined
+305	 # There is bad data in the aperture
+.fi
+
+.ih
+EXAMPLES
+
+1. Perform aperture photometry interactively for a few stars in dev$ypix using
+the display and the image cursor.
+
+.nf
+	ap> display dev$ypix 1 fi+
+
+	... display the image
+
+	ap> qphot dev$ypix 5. 10. 5. 2.,4.,6.0 
+
+	... move image cursor to objects of interest and tap space bar
+
+	... a 1 line summary will be printed on the standard output
+	    for each object measured
+
+	... type q to quit and q again to confirm the quit
+
+	... full output will appear in ypix.mag.1
+.fi
+
+
+2. Perform aperture photometry interactively for a few stars in dev$ypix
+using the contour plot and the graphics cursor. This option is only useful
+for those (now very few) users who have access to a graphics terminal but
+not to an image display server. Setup the task parameters using the
+interactive setup menu defined by the i key command as in example 1.
+
+
+.nf
+        ap> show stdimcur
+
+        ... record the default value of stdimcur
+
+	ap> set stdimcur = stdgraph
+
+        ... define the image cursor to be the graphics cursor
+
+        ap> contour dev$ypix
+
+        ... make a contour plot of dev$ypix
+
+	ap> contour dev$pix >G ypix.plot1
+
+	... store the contour plot of dev$ypix in the file ypix.plot1
+
+	ap> qphot dev$ypix 5. 10. 5. 2.,4.,6.0 
+
+        ... type ? to see the help screen
+
+	... move image cursor to objects of interest and tap space bar
+
+	... a 1 line summary will be printed on the standard output
+	    for each object measured
+
+	... type q to quit and q again to confirm the quit
+
+	... full output will be written to ypix.mag.2
+
+        ap> set stdimcur = <default>
+
+        ... reset stdimcur to its previous value
+.fi
+
+
+
+3. Setup and run QPHOT interactively on a list of objects temporarily
+overriding the fwhmpsf, sigma, cbox, annulus, dannulus, and apertures
+ parameters determined in examples 1 or 2.
+
+.nf
+        ap> daofind dev$ypix fwhmpsf=2.6 sigma=25.0 verify-
+
+        ... make a coordinate list
+
+        ... the output will appear in the text file ypix.coo.1
+
+        ap> qphot dev$ypix 7.0 12.0 5.0 "3.0,5.0" coords=ypix.coo.1
+
+        ... type ? for optional help
+
+
+        ... move the graphics cursor to the stars and tap space bar
+
+                                or
+
+        ... select stars from the input coordinate list with m / :m #
+            and measure with spbar
+
+        ... measure stars selected from the input coordinate list
+            with n / n #
+
+        ... a one line summary of results will appear on the standard output
+            for each star measured
+
+	... type q to quit and q again to confirm the quit
+
+        ... the output will appear in ypix.mag.3 ...
+.fi
+
+
+4. Display and measure some stars in an image section and write the output
+coordinates in the coordinate system of the parent image.
+
+.nf
+        ap> display dev$ypix[150:450,150:450] 1
+
+        ... display the image section
+
+        ap> qphot dev$ypix[150:450,150:450] 7.0 12.0 5.0 "3.0,5.0" wcsout=tv
+
+        ... move cursor to stars and type spbar
+
+        ... type q to quit and q again to confirm quit
+
+        ... output will appear in ypix.mag.4
+
+        ap> pdump ypix.mag.4 xc,yc yes | tvmark 1 STDIN col=204
+.fi
+
+
+5. Run QPHOT in batch mode using the coordinate file and the previously
+saved parameters.
+
+.nf
+        ap> qphot dev$ypix 7. 12.0 5.0 "3.0,5.0" coords=ypix.coo.1 inter-
+
+        ... output will appear in ypix.mag.5 ...
+.fi
+
+
+6. Repeat example 5 but assume that the input coordinate are ra and dec
+in degrees and degrees and submit the task to the background.
+
+.nf
+        ap> display dev$ypix
+
+        ap> rimcursor wcs=world > radec.coo
+
+        ... move to selected stars and type any key
+
+        ... type ^Z to quit
+
+        ap> qphot dev$ypix 7.0 12.0 5.0 "3.0,5.0" coords=radec.coo \
+            wcsin=world inter- &
+
+        ... output will appear in ypix.ctr.6
+
+        ap> pdump ypix.mag.6 xc,yc yes | tvmark 1 STDIN col=204
+
+        ... mark the stars on the display
+.fi
+
+
+7. Run QPHOT interactively without using the image display.
+
+.nf
+        ap> show stdimcur
+
+        ... record the default value of stdimcur
+
+        ap> set stdimcur = text
+
+        ... set the image cursor to the standard input
+
+        ap> qphot dev$ypix 7.0 12.0 5.0 "3.0,5.0" coords=ypix.coo.1
+
+        ... type ? for optional help
+
+        ... type :m 3 to set the initial coordinates to those of the
+            third star in the list
+
+        ... type "442 409 101 i" to enter the interactive setup menu
+        ... enter the maximum radius in pixels for the radial profile or
+            accept the default with a CR
+        ... type v to enter the default menu
+        ... reset cbox, annulus, dannulus, and apertures using the graphics
+            cursor and the stellar radial profile plot
+        ... typing <CR> after the prompt leaves the parameter at its default
+            value
+	... type q to quit the setup menu
+
+        ... type r to rewind the coordinate list
+
+        ... type l to measure all the stars in the coordinate list
+
+        ... a one line summary of the answers will appear on the standard
+            output for each star measured
+
+        ... type q to quit followed by q to confirm the quit
+
+        ... full output will appear in the text file ypix.mag.7
+
+        ap> set stdimcur = <default>
+
+        ... reset the value of stdimcur
+.fi
+
+8. Use a image cursor command file to drive the qphot task. The cursor command
+file shown below computes the centers, sky values, and magnitudes  for 3 stars
+and quits the task.
+
+.nf
+        ap> type cmdfile
+        442 410 101 \040
+        349 188 101 \040
+        225 131 101 \040
+        q
+
+        ap> qphot dev$ypix 7.0 12.0 5.0 "3.0,5.0" icommands=cmdfile
+
+        ... full output will appear in ypix.mag.8
+.fi
+
+
+.ih
+BUGS
+
+It is the responsibility of the user to make sure that the image displayed
+in the image display is the same as that specified by the image parameter.
+
+Commands which draw to the image display are disabled by default.
+To enable graphics overlay on the image display, set the display
+parameter to "imdr", "imdg", "imdb", or "imdy" to get red, green,
+blue or yellow overlays. It may be necessary to run gflush and to
+redisplay the image to get the overlays position correctly.
+
+.ih
+SEE ALSO
+phot,wphot,polyphot
+.endhelp
diff --git a/noao/digiphot/apphot/doc/radprof.hlp b/noao/digiphot/apphot/doc/radprof.hlp
new file mode 100644
index 00000000..c6d79251
--- /dev/null
+++ b/noao/digiphot/apphot/doc/radprof.hlp
@@ -0,0 +1,813 @@
+.help radprof May00 noao.digiphot.apphot
+.ih
+NAME
+radprof -- compute the radial profile of an object
+.ih
+USAGE
+radprof image radius step
+.ih
+PARAMETERS
+.ls image
+The name of the image containing the objects to be measured.
+.le
+.ls radius, step
+The size and resolution of the computed radial profile in scale units which is
+equal to radius * \fIscale\fR  and step * \fIscale\fR in pixels.
+.le
+.ls coords = ""
+The list of text files containing initial coordinates for the objects to
+be centered. Objects are listed in coords one object per line with the
+initial coordinate values in columns one and two. The number of coordinate
+files must be zero, one, or equal to the number of images.  If coords is
+"default", "dir$default", or a directory specification then a coords file name
+of the form dir$root.extension.version is constructed and searched for,
+where dir is the directory, root is the root image name, extension is "prf"
+and version is the next available version number for the file.
+.le
+.ls output = ""
+The name of the results file or results directory.
+If output is "default", "dir$default" or a directory specification then an
+output file name of the form dir$root.extension.version is constructed, where
+dir is the directory, root is the root image name, extension is "prf" and
+version is the next available version of the file. If output is undefined,
+then no output file is created. If output is defined, the number of output files
+is either 1 or the same as the number of input images.
+.le
+.ls plotfile = ""
+The name of the file containing radial profile plots of the stars written
+to the output file. If plotfile is defined then a radial profile plot
+is written to plotfile every time a record is written to \fIoutput\fR.
+The user should be aware that this can be a time consuming operation.
+.le
+.ls datapars = ""
+The name of the file containing the data dependent parameters. The critical
+parameters \fIfwhmpsf\fR and \fIsigma\fR are located here. If \fIdatapars\fR
+is undefined then the default parameter set in uparm directory is used.
+.le
+.ls centerpars = ""
+The name of the file containing the centering parameters. The critical
+parameters \fIcalgorithm\fR and \fIcbox\fR are located here.
+If \fIcenterpars\fR is undefined then the default parameter set in
+uparm directory is used.
+.le
+.ls fitskypars = ""
+The name of the text file containing the sky fitting parameters. The critical
+parameters \fIsalgorithm\fR, \fIannulus\fR, and \fIdannulus\fR are located here.
+If \fIfitskypars\fR is undefined then the default parameter set in uparm
+directory is used.
+.le
+.ls photpars = ""
+The name of the file containing the photometry parameters. The critical
+parameter \fIapertures\fR is located here.  If \fIphotpars\fR is undefined
+then the default parameter set in uparm directory is used.
+.le
+.ls order = 5
+The number of pieces in the spline fit.
+.le
+.ls nreject = 1
+The maximum number of rejection cycles.
+.le
+.ls kreject = 3.0
+The k-sigma rejection limit for the radial profile fit.
+.le
+.ls interactive = yes
+Run the task interactively ?
+.le
+.ls radplots = yes
+If \fIradplots\fR is "yes" and RADPROF  is run in interactive mode, a radial
+profile of each star is plotted on the screen after the star is measured.
+.le
+.ls icommands = ""
+The image cursor or image cursor command file.
+.le
+.ls gcommands = ""
+The graphics cursor or graphics cursor command file.
+.le
+.ls wcsin = ")_.wcsin", wcsout = ")_.wcsout"
+The coordinate system of the input coordinates read from \fIcoords\fR and
+of the output coordinates written to \fIoutput\fR respectively. The image
+header coordinate system is used to transform from the input coordinate
+system to the "logical" pixel coordinate system used internally,
+and from the internal "logical" pixel coordinate system to the output
+coordinate system. The input coordinate system options are "logical", "tv",
+"physical", and "world". The output coordinate system options are "logical",
+"tv", and "physical". The image cursor coordinate system is assumed to
+be the "tv" system.
+.ls logical
+Logical coordinates are pixel coordinates relative to the current image.
+The  logical coordinate system is the coordinate system used by the image
+input/output routines to access the image data on disk. In the logical
+coordinate system the coordinates of the first pixel of a  2D image, e.g.
+dev$ypix  and a 2D image section, e.g. dev$ypix[200:300,200:300] are
+always (1,1).
+.le
+.ls tv
+Tv coordinates are the pixel coordinates used by the display servers. Tv
+coordinates  include  the effects of any input image section, but do not
+include the effects of previous linear transformations. If the input
+image name does not include an image section, then tv coordinates are
+identical to logical coordinates.  If the input image name does include a
+section, and the input image has not been linearly transformed or copied from
+a parent image, tv coordinates are identical to physical coordinates.
+In the tv coordinate system the coordinates of the first pixel of a
+2D image, e.g. dev$ypix and a 2D image section, e.g. dev$ypix[200:300,200:300]
+are (1,1) and (200,200) respectively.
+.le
+.ls physical
+Physical coordinates are pixel coordinates invariant  with respect to linear
+transformations of the physical image data.  For example, if the current image
+was created by extracting a section of another image,  the  physical
+coordinates of an object in the current image will be equal to the physical
+coordinates of the same object in the parent image,  although the logical
+coordinates will be different.  In the physical coordinate system the
+coordinates of the first pixel of a 2D image, e.g. dev$ypix and a 2D
+image section, e.g. dev$ypix[200:300,200:300] are (1,1) and (200,200)
+respectively.
+.le
+.ls world
+World coordinates are image coordinates in any units which are invariant
+with respect to linear transformations of the physical image data. For
+example, the ra and dec of an object will always be the same no matter
+how the image is linearly transformed. The units of input world coordinates
+must be the same as those expected by the image header wcs, e. g.
+degrees and degrees for celestial coordinate systems.
+.le
+The wcsin and wcsout parameters default to the values of the package
+parameters of the same name. The default values of the package parameters
+wcsin and wcsout are "logical" and "logical" respectively.
+.le
+.le
+.ls cache = ")_.cache"
+Cache the image pixels in memory. Cache may be set to the value of the apphot
+package parameter (the default), "yes", or "no". By default cacheing is 
+disabled.
+.le
+.ls verify = ")_.verify"
+Verify the critical parameters in non-interactive mode ? Verify may be set to
+the apphot package parameter value (the default), "yes", or "no".
+.le
+.ls update = ")_.update"
+Update the critical parameter in non-interactive mode if verify is yes ?
+Update may be set to the apphot package parameter value (the default), "yes",
+or "no".
+.le
+.ls verbose = ")_.verbose"
+Print messages on the screen in non-interactive mode ? Verbose may be set
+to the apphot package parameter value (the default), "yes", or "no".
+
+.le
+.ls graphics = ")_.graphics"
+The default graphics device.  Graphics may be set to the apphot package
+parameter value (the default), "yes", or "no.
+.le
+.ls display = ")_.display"
+The default display device. Display may be set to the apphot package
+parameter value (the default), "yes", or "no. By default graphics overlay
+is disabled.  Setting display to one of "imdr", "imdg", "imdb", or "imdy"
+enables graphics overlay with the IMD graphics kernel.  Setting display to
+"stdgraph" enables RADPROF to work interactively from a contour plot.
+.le
+
+.ih
+DESCRIPTION
+
+The radial profiles of objects in the image \fIimage\fR are computed
+the object center out to the radius \fIradius * scale\fR, in steps of
+\fIstep * scale\fR pixels, and plotted. The initial positions are
+read from the image cursor or the text file \fIcoords\fR.
+
+The coordinates read from \fIcoords\fR are assumed to be in coordinate
+system defined by \fIwcsin\fR. The options are "logical", "tv", "physical",
+and "world" and the transformation from the input coordinate system to
+the internal "logical" system is defined by the image coordinate system.
+The simplest default is the "logical" pixel system. Users working on with
+image sections but importing pixel coordinate lists generated from the parent
+image must use the "tv" or "physical" input coordinate systems.
+Users importing coordinate lists in world coordinates, e.g. ra and dec,
+must use the "world" coordinate system and may need to convert their
+equatorial coordinate units from hours and degrees to degrees and degrees first.
+
+The coordinates written to \fIoutput\fR are in the coordinate
+system defined by \fIwcsout\fR. The options are "logical", "tv",
+and "physical". The simplest default is the "logical" system. Users
+wishing to correlate the output coordinates of objects measured in
+image sections or mosaic pieces with coordinates in the parent
+image must use the "tv" or "physical" coordinate systems.
+
+If \fIcache\fR is yes and the host machine physical memory and working set size
+are large enough, the input image pixels are cached in memory. If cacheing
+is enabled and RADPROF is run interactively the first measurement will appear
+to take a long time as the entire image must be read in before the measurement
+is actually made. All subsequent measurements will be very fast because RADPROF
+is accessing memory not disk. The point of cacheing is to speed up random
+image access by making the internal image i/o buffers the same size as the
+image itself. However if the input object lists are sorted in row order and
+sparse cacheing may actually worsen not improve the execution time. Also at
+present there is no point in enabling cacheing for images that are less than
+or equal to 524288 bytes, i.e. the size of the test image dev$ypix, as the
+default image i/o buffer is exactly that size. However if the size of dev$ypix
+is doubled by converting it to a real image with the chpixtype task then the
+effect of cacheing in interactive is can be quite noticeable if measurements
+of objects in the top and bottom halfs of the image are alternated.
+
+RADPROF can be run either interactively or in batch mode by setting the
+interactive switch to yes. In interactive mode starting x and y coordinates
+can either be read directly from the image cursor or read from the text
+file specified by \fIcoords\fR. In interactive mode the results are
+plotted on the terminal. In batch mode the estimated positions
+are read from the text file \fIcoords\fR or the image cursor parameter
+\fIicommands\fR is redirected to a text file containing a list of cursor
+commands.
+
+.ih
+CURSOR COMMANDS
+
+The RADPROF cursor commands are listed below.
+
+.nf
+	Interactive Keystroke Commands
+
+?	Print help
+:	Colon commands
+v	Verify the critical parameters
+w	Store the current parameters
+d	Plot radial profile of current star
+i	Interactively set parameters using current star
+c	Fit center of current star
+t	Fit sky around the cursor position
+a       Average sky values fit around several cursor positions
+s	Fit sky around the current star 
+p	Fit star using current sky
+o	Fit star using current sky, output results
+f	Fit current star
+spbar	Fit current star, output results
+m	Move to next star in coordinate list
+n	Fit next star in coordinate list, output results
+l	Fit remaining stars in coordinate list, output results	
+r	Rewind the coordinate list
+e	Print error messages
+q	Exit task
+
+
+	Colon Commands
+
+:show	[data/center/sky/fit]	List the parameters
+:m [n]	Move to next [nth] object in coordinate list
+:n [n]	Fit next [nth] object in coordinate list, output results
+
+
+	Colon Parameter Editing Commands
+
+# Image and file name parameters
+
+:image		[string]	Image name
+:coords		[string]	Coordinate file name
+:output		[string]	Output file name
+
+# Data dependent parameters
+
+:scale		[value]		Image scale (units per pixel)
+:fwhmpsf	[value]		Full-width half-maximum of psf (scale units)
+:emission	[y/n]		Emission features (y), absorption (n)
+:sigma		[value]		Standard deviation of sky (counts)
+:datamin	[value]		Minimum good pixel value (counts)
+:datamax	[value]		Maximum good pixel value (counts)
+
+# Noise parameters
+
+:noise		[string]	Noise model (constant|poisson)
+:gain		[string]	Gain image header keyword
+:ccdread	[string]	Readout noise image header keyword
+:epadu		[value]		Gain (electrons per adu)
+:readnoise	[value]		Readout noise (electrons)
+
+# Observing parameters
+
+:exposure	[value]		Exposure time image header keyword
+:airmass	[string]	Airmass image header keyword
+:filter		[string]	Filter image header keyword
+:obstime	[string]	Time of observation image header keyword
+:itime		[value]		Integration time (time units)
+:xairmass	[value]		Airmass value (number)
+:ifilter	[string]	Filter id string
+:otime		[string]	Time of observation (time units)
+
+# Centering algorithm parameters
+
+:calgorithm	[string]	Centering algorithm
+:cbox		[value]		Width of the centering box (scale units)
+:cthreshold	[value]		Centering intensity threshold (sigma)
+:cmaxiter	[value]		Maximum number of iterations
+:maxshift	[value]		Maximum center shift (scale units)
+:minsnratio	[value]		Minimum S/N ratio for centering
+:clean		[y/n]		Clean subraster before centering
+:rclean		[value]		Cleaning radius (scale units)
+:rclip		[value]		Clipping radius (scale units)
+:kclean		[value]		Clean K-sigma rejection limit (sigma)
+
+# Sky fitting algorithm parameters
+
+:salgorithm	[string]	Sky fitting algorithm
+:skyvalue	[value]		User supplied sky value (counts)
+:annulus	[value]		Inner radius of sky annulus (scale units)
+:dannulus	[value]		Width of sky annulus (scale units)
+:khist		[value]		Sky histogram extent (+/- sigma)
+:binsize	[value]		Resolution of sky histogram (sigma)
+:sloclip	[value]		Low-side clipping factor in percent
+:shiclip	[value]		High-side clipping factor in percent
+:smaxiter	[value]		Maximum number of iterations
+:smooth		[y/n]		Lucy smooth the sky histogram
+:snreject	[value]		Maximum number of rejection cycles
+:sloreject	[value]		Low-side pixel rejection limits (sky sigma)
+:shireject	[value]		High-side pixel rejection limits (sky sigma)
+:rgrow		[value]		Region growing radius (scale units)
+
+# Photometry parameters
+
+:apertures	[string]	List of apertures (scale units)
+:zmag		[value]		Zero point of magnitude scale
+
+# Profile fitting parameters
+
+:radius		[value]		Maximum profile radius (scale units)
+:step		[value]		Step size for computed profile (scale units)
+:order		[value]		Number of spline pieces in fit
+:kreject	[value]		K-sigma rejection for fit (fit sigma)
+:nreject	[value]		Maximum number of rejection cycles
+
+# Marking and plotting parameters
+
+:mkcenter	[y/n]		Mark computed centers on display
+:mksky		[y/n]		Mark the sky annuli on the display
+:mkapert	[y/n]		Mark apertures on the display
+:radplot	[y/n]		Plot the radial profile
+
+
+
+The following commands are available from inside the interactive setup menu.
+
+
+                    Interactive Radprof Setup Menu
+
+	v	Mark and verify the critical parameters (f,c,s,a,d,r,w,x)
+
+	f	Mark and verify the psf full-width half-maximum
+	s	Mark and verify the standard deviation of the background
+	l	Mark and verify the minimum good data value
+	u	Mark and verify the maximum good data value
+
+	c	Mark and verify the centering box width
+	n	Mark and verify the cleaning radius
+	p	Mark and verify the clipping radius
+
+	a	Mark and verify the inner radius of the sky annulus
+	d	Mark and verify the width of the sky annulus
+	g	Mark and verify the region growing radius
+
+	r	Mark and verify the photometry aperture radii
+	w	Mark and verify the radius of the radial profile
+	x	Mark and verify the step size of radial profile
+.fi
+
+.ih
+ALGORITHMS
+
+Prior to computing the radial profile of the star, RADPROF computes the
+center, estimates a sky value, and does aperture photometry on the star
+using the parameters in the DATAPARS, CENTERPARS, FITSKYPARS, and
+PHOTPARS tasks.
+
+Next the radial and intensity coordinates of all the pixels inside
+\fIradius * scale\fR are computed using the calculated center and sky
+values and fit to a least squares cubic spline of order \fIorder\fR with
+optional bad data rejection.  The fit is interpolated at intervals of
+\fIstep_size * scale\fR to derive the output profile and estimate the
+full width at half maximum of the object. The fit noise model parameters
+are defined in DATAPARS.
+
+.ih
+OUTPUT
+
+In interactive mode the following quantities are printed on the standard
+output as each object is measured.  Error is a simple string which
+indicates whether an error was encountered in the
+the centering algorithm, the sky fitting algorithm, the photometry
+algorithm or the spline fitting algorithm respectively.
+Mag and merr are the magnitudes and errors in
+aperture N and xcenter, ycenter and msky are the
+x and y centers and the sky value respectively.
+Pfwhm is the fitted full width half maximum of the fitted radial profile.
+
+.nf
+    image  xcenter  ycenter  msky  pfwhm  mag[N]  merr[N] iers
+.fi
+
+In both interactive and batch mode full output is written to the text file
+\fIoutput\fR. At the beginning of each file is a header listing the
+current values of the parameters when the first stellar record was written.
+These parameters can be subsequently altered. For each star measured the
+following record is written
+
+.nf
+	image  xinit  yinit  id  coords  lid
+	   xcenter  ycenter  xshift  yshift  xerr  yerr  cier error
+	   msky  stdev  sskew  nsky  nsrej  sier  serror
+	   itime  xairmass  ifilter  otime
+	   rapert  sum  area  flux mag  merr  pier  perr
+	   pfwhm  inorm  tinorm  rier  rerror
+	   pradius  intensity  tintensity
+.fi
+
+Image and coords are the name of the image and coordinate file respectively.
+Id and lid are the sequence numbers of stars in the output and coordinate
+files respectively. Cier and cerror are the error code and accompanying
+error message respectively.  Xinit, yinit, xcenter, ycenter, xshift, yshift,
+and xerr, yerr are self explanatory and output in pixel units. The sense of
+the xshift and yshift definitions is the following.
+
+.nf
+	xshift = xcenter - xinit
+	yshift = ycenter - yinit
+.fi
+
+Sier and serror are the error code and accompanying error message respectively.
+Msky, stdev and sskew are the best estimate of the sky value (per pixel),
+standard deviation and skew respectively. Nsky and nsrej are the number of
+sky pixels and the number of sky pixels rejected respectively.
+
+Itime is the exposure time, xairmass is self-evident, filter is an id
+string specifying the filter used during the observation and otime is
+a string containing the time of observation in whatever units the user
+has defined.
+
+Rapert, sum, area and flux are the radius of the aperture in pixels, the total
+number of counts including sky in the aperture, the area of the aperture in
+square pixels, and the total number of counts in the aperture excluding sky.
+Mag and merr are the magnitude and error in the magnitude in the aperture
+(see below).
+
+.nf
+	flux = sum - area * msky
+	 mag = zmag - 2.5 * log10 (flux) + 2.5 * log10 (itime)
+	merr = 1.0857 * error / flux
+       error = sqrt (flux / epadu + area * stdev**2 +
+	       area**2 * stdev**2 / nsky)
+.fi
+
+Pier and perror are photometry error code and accompanying error message.
+
+Pfwhm is the full width at half intensity of the fitted profile. Inorm and
+tinorm are the normalization factors for the fitted radial profile and the
+fitted total intensity profile respectively. Rier and rerror are the spline
+fitting error code and accompanying error message. Pradius, intensity
+and tintensity are the computed radii, intensity and total intensity
+values at each radial step.
+
+
+.ih
+ERRORS
+
+If the object centering was error free then the field cier will be zero.
+Non-zero values of cier flag the following error conditions.
+
+.nf
+	0        # No error
+	101      # The centering box is off image
+	102      # The centering box is partially off the image
+	103      # The S/N ratio is low in the centering box
+	104      # There are two few points for a good fit
+	105      # The x or y center fit is singular
+	106      # The x or y center fit did not converge
+	107      # The x or y center shift is greater than maxshift
+	108      # There is bad data in the centering box
+.fi
+
+If all goes well during the sky fitting process then the error code sier
+will be 0. Non-zero values of sier flag the following error conditions.
+
+.nf
+	0         # No error
+	201       # There are no sky pixels in the sky annulus
+	202       # Sky annulus is partially off the image
+	203       # The histogram of sky pixels has no width
+	204       # The histogram of sky pixels is flat or concave
+	205       # There are too few points for a good sky fit
+	206       # The sky fit is singular
+	207       # The sky fit did not converge
+	208       # The graphics stream is undefined
+	209       # The file of sky values does not exist
+	210       # The sky file is at EOF
+	211       # Cannot read the sky value correctly
+	212       # The best fit parameter are non-physical
+.fi
+
+If no error occurs during the measurement of the magnitudes then pier is
+0. Non-zero values of pier flag the following error conditions.
+
+.nf
+	0        # No error
+	301      # The aperture is off the image
+	302      # The aperture is partially off the image
+	303      # The sky value is undefined
+	305      # There is bad data in the aperture
+.fi
+
+If no error occurs during the profile fitting then rier is 0.
+Non-zero values of rier flag the following error conditions.
+
+.nf
+	0       # No error
+	901     # The profile region is off the image
+	902     # The profile region is partially off the image
+	903	# There are too few points in the profile
+	904	# The fit is singular
+	905     # The sky value is undefined
+.fi
+
+.ih
+EXAMPLES
+
+1. Compute the radial profiles for a few  stars in dev$ypix using the
+display and the image cursor. Setup the task parameters using the
+interactive setup menu defined by the i key command.
+
+.nf
+	ap> display dev$ypix 1 fi+
+
+	... display the image
+
+	ap> radprof dev$ypix 7.0 0.5 
+
+	... type ? to print a short help page
+
+	... move the image cursor to a star
+	... type i to enter the interactive setup menu
+	... enter maximum radius in pixels of the radial profile or
+	    CR to accept the default value
+	... set the fwhmpsf, centering radius, inner and outer sky
+    	    annuli, apertures, sigma, profile radius and step size
+	    using the graphics cursor and the stellar radial profile
+	    plot
+	... typing <CR> leaves everything at the default value
+	... type q to quit the setup menu
+
+	... type the v key to verify the parameters
+
+	... type the w key to save the parameters in the parameter files
+
+	... move the image cursor to the star of interest and tap
+	    the space bar
+
+	... type :order 3 to change the spline order and see if the
+	     fit improves, if it does type w
+
+	... a radial profile plot will appear on the graphics terminal
+
+	... type q to quit and q to confirm the quit
+
+	... by default radprof does not create an output file
+.fi
+
+2. Compute the radial profiles for a few  stars in dev$ypix using a contour
+plot and the graphics cursor. Setup the task parameters using the interactive
+setup menu defined by the i key command. This option is only useful for
+those users (now very few) who do not have access to an image display server
+but do have access to a graphics terminal. 
+
+.nf
+	ap> show stdimcur
+
+	... determine the default value of stdimcur
+
+	ap> set stdimcur = stdgraph
+
+	... define the image cursor to be the graphics cursor
+
+	ap> contour dev$ypix 
+
+	... make a contour plot of dev$ypix
+
+	ap> contour dev$ypix  >G ypix.plot1
+
+	... store the contour plot of dev$ypix in ypix.plot1
+
+	ap> radprof dev$ypix 7.0 0.5
+
+	... type ? to print the help page
+
+	... move graphics cursor to a star
+	... type i to enter the interactive setup menu
+	... enter maximum radius in pixels of the radial profile or
+	    hit CR to accept the default value
+	... set the fwhmpsf, centering radius, inner and outer sky annuli,
+	    apertures, sigma, profile radius and step size using the
+	    graphics cursor and the stellar radial profile plot
+	... typing <CR> leaves everything at the default value
+	... type q to quit the setup menu
+
+	... type the v key to verify the parameters
+
+	... type the w key to save the parameters in the parameter files
+
+	... type :.read ypix.plot1 to reload the contour plot
+
+	... move the graphics cursor to the star of interest and tap
+	    the space bar
+
+	... a radial profile plot will appear on the graphics terminal
+
+	... repeat the above sequence for each additional star
+
+	... type q to quit and q to confirm the quit
+
+	... by default radprof does not create an output file
+.fi
+
+3. Setup and run RADPROF interactively on a list of objects temporarily
+overriding the fwhmpsf, sigma, cbox, annulus, dannulus, apertures,
+radius, and step  parameters determined in examples 1 or 2.
+
+.nf
+        ap> daofind dev$ypix fwhmpsf=2.6 sigma=25.0 verify-
+
+        ... make a coordinate list
+
+        ... the output will appear in the text file ypix.coo.1
+
+        ap> radprof dev$ypix 7.0 0.5 fwhmpsf=2.6 sigma=5.0 cbox=7.0 \
+            annulus=10.0 dannulus=5.0 apertures=5.0 coords=ypix.coo.1
+
+        ... type ? for optional help
+
+
+        ... move the graphics cursor to the stars and tap space bar
+
+                                or
+
+        ... select stars from the input coordinate list with m / :m #
+            and measure with spbar
+
+        ... measure stars selected from the input coordinate list
+            with n / n #
+
+        ... a one line summary of results will appear on the standard output
+            for each star measured
+
+        ... type q to quit and q again to confirm the quit
+
+        ... by default radprof does not create an output file
+.fi
+
+4. Display and fit some stars in an image section and write the output
+coordinates in the coordinate system of the parent image.
+
+.nf
+        ap> display dev$ypix[150:450,150:450] 1
+
+        ... display the image section
+
+        ap> radprof dev$ypix[150:450,150:450] 7.0 0.5 output=default \
+            wcsout=tv 
+
+        ... move cursor to stars and type spbar
+
+        ... type q to quit and q again to confirm quit
+
+        ... output will appear in ypix.prf.1
+
+        ap> pdump ypix.prf.1 xc,yc yes | tvmark 1 STDIN col=204
+.fi
+
+
+5. Run RADPROF in batch mode using the coordinate file and the previously
+saved parameters. Save the text and plot output. 
+
+.nf
+	ap> radprof dev$ypix 7. 0.5 coords=ypix.coo.1 output="default" \
+	    plotfile=ypix.rplots inter- verify-
+
+	... output will appear in m92.prf.2 and ypix.rplots
+
+	ap> gkidir ypix.rplots
+
+	... get a listing of the plots in ypix.rplots
+
+	ap> gkiextract ypix.rplots 1-3 | stdplot dev=lw16
+
+	... extract plots 1-3 and plot them on device lw16
+.fi
+
+6. Repeat example 5 but assume that the input coordinates are ra and dec
+in degrees and degrees, turn off verification, and submit the task to to
+the background.
+
+.nf
+        ap> display dev$ypix 1
+
+        ap> rimcursor wcs=world > radec.coo
+
+        ... move to selected stars and type any key
+
+        ... type ^Z to quit
+
+        ap> radprof dev$ypix 7.0 0.5 coords=radec.coo output=default \
+            plotfile=ypix.rplots2 wcsin=world verify- inter- &
+
+        ... output will appear in ypix.prf.3, plots will appear in
+            ypix.rplots2
+
+        ap> pdump ypix.prf.3 xc,yc yes | tvmark 1 STDIN col=204
+
+        ... mark the stars on the display
+.fi
+
+
+7. Run RADPROF interactively without using the image display.
+
+.nf
+        ap> show stdimcur
+
+        ... record the default value of stdimcur
+
+        ap> set stdimcur = text
+
+        ... set the image cursor to the standard input
+
+        ap> radprof dev$ypix 7.0 0.5 coords=ypix.coo.1
+
+        ... type ? for optional help
+
+        ... type :m 3 to set the initial coordinates to those of the
+            third star in the list
+
+        ... type i to enter the interactive setup menu
+        ... enter the maximum radius in pixels for the radial profile or
+            accept the default with a CR
+        ... type v to enter the default menu
+        ... set the fwhmpsf, centering radius, inner and outer sky annuli,
+            apertures, and sigma using the graphics cursor and the
+            stellar radial profile plot
+        ... typing <CR> after the prompt leaves the parameter at its default
+            value
+        ... type q to quit the setup menu
+
+        ... type r to rewind the coordinate list
+
+        ... type n to measure the next star
+
+        ... a one line summary of the answers will appear on the standard
+            output for each star measured
+
+        ... type q to quit followed by q to confirm the quit
+
+	... by default no output file is written
+
+        ap> set stdimcur = <default>
+
+        ... reset the value of stdimcur
+.fi
+
+8. Use a image cursor command file to drive the RADPROF task. The cursor
+command file shown below sets the cbox, annulus, dannulus, and apertures
+parameters computes the centers, sky values, magnitudes, and readial profiles
+for 3 stars, updates the parameter files, and quits the task.
+
+.nf
+        ap> type cmdfile
+        : cbox 9.0
+        : annulus 12.0
+        : dannulus 5.0
+        : apertures 5.0
+        442 410 101 \040
+        349 188 101 \040
+        225 131 101 \040
+        w
+        q
+
+        ap> radprof dev$ypix 7.0 0.5 icommands=cmdfile  \
+	    plotfile=ypix.rplots3 verify-
+
+        ... by default no output file is written, plots will appear in
+	    ypix.rplots3
+.fi
+
+
+.ih
+BUGS
+
+It is currently the responsibility of the user to make sure that the
+image displayed in the frame is the same as that specified by the image
+parameter.
+
+Commands which draw to the image display are disabled by default.
+To enable graphics overlay on the image display, set the display
+parameter to "imdr", "imdg", "imdb", or "imdy" to get red, green,
+blue or yellow overlays and set the centerpars mkcenter switch to
+"yes", the fitskypars mksky switch to"yes", or the photpars mkapert
+witch to "yes". It may be necessary to run gflush and to redisplay the image
+to get the overlays position correctly.
+
+.ih
+SEE ALSO
+datapars, centerpars, fitskypars, photpars
+.endhelp
diff --git a/noao/digiphot/apphot/doc/specs/Ap.doc b/noao/digiphot/apphot/doc/specs/Ap.doc
new file mode 100644
index 00000000..66744d58
--- /dev/null
+++ b/noao/digiphot/apphot/doc/specs/Ap.doc
@@ -0,0 +1,1071 @@
+APPHOT (Aug83)    Digital Aperture Photometry Package     APPHOT (Aug83)
+
+
+
+1. Introduction
+
+    The  APPHOT  package  will  provide a set of routines for performing
+aperture photometry  on  uncrowded  or  moderately  crowded  fields,  in
+either  interactive  or  batch  mode.   The  basic  photometry technique
+employed  shall  be  fractional-pixel  aperture  integration;   no   PSF 
+fitting  techniques  shall  be  employed,  and  no  knowledge of the PSF
+shall be required.  This document presents the formal  requirements  and
+specifications  for  the  package,  and  describes  the algorithms to be
+used.
+
+
+
+2. Requirements
+
+    (1) The program shall take as input an IRAF imagefile  containing  a
+        starfield  which  has  been  corrected  for  pixel to pixel gain
+        variations,  high  frequency  fluctuations  in  the  background, 
+        nonlinearity,  and  any other instrumental defects affecting the
+        intensity value of a pixel.
+
+    (2) Given as input the approximate coordinates of  a  single  object
+        in   the   image,   the  program  shall  perform  the  following 
+        operations:
+
+            o   Determine a constant background  value  by  analysis  of
+                an   annular   region   surrounding   the  object.   The 
+                background is assumed to be flat in the  region  of  the
+                object,   but   may  contain  contaminating  objects  or 
+                defects which shall be detected and  eliminated  by  the
+                fitting  algorithm.   It  shall  be  permissible for the
+                background region to extend  beyond  the  boundaries  of
+                the  image;  the  out  of  bounds  region of the annulus
+                shall be excluded from the fit.
+
+            o   Determine  the  center  of  the   object,   taking   the 
+                approximate  object  coordinates  given  as  input  as a
+                starting  point.   The  center  determination  shall  be 
+                resistant   to   the  affects  of  nearby  contaminating 
+                objects.  The centering algorithm may  assume  that  the
+                object  is  circularly symmetric, or nearly so, and that
+                the object flux is positive.
+
+            o   Determine  the  integral  of  object  minus   background 
+                within  one  or  more  circular  apertures centered upon
+                the object.  The integration shall  be  performed  using
+                partial  pixel  techniques,  to  minimize the effects of
+                sampling.   If  the  aperture  contains  any  indefinite 
+                pixels,  or  if the aperture extends beyond the boundary
+                of the image, an indefinite result shall be returned.
+
+    (3) The  following  options  shall  be  provided   to   modify   the 
+        operation of the above functions:
+
+
+                                  -1-
+APPHOT (Aug83)    Digital Aperture Photometry Package     APPHOT (Aug83)
+
+
+
+            o   Use  a  user  supplied  constant  background  value  and 
+                background  noise  estimate  instead  of   fitting   the 
+                background.
+
+            o   Use  the  starting  center  as  the actual center in all
+                cases.
+
+            o   Use the starting center as  the  actual  center  if  the
+                object  is  very  faint,  but tweak up the center if the
+                signal to noise is above a certain threshold.
+
+            o   Allow the object aperture to  extend  beyond  the  image
+                boundary,  using  only  that  portion  of  the  aperture 
+                which  is  in  bounds  when   computing   the   aperture 
+                integral.
+
+    (4) At  a  minimum, the following parameters shall be calculated and
+        output for each object:
+
+            o   The coordinates of the object, and the  estimated  error
+                in these coordinates.
+
+            o   The  mode  and standard deviation of the background; the
+                number of pixels left in  the  background  region  after
+                pixel rejection.
+
+            o   The  magnitude  of  the  object,  to  within an arbitary
+                zero-point,  and  the  statistical  uncertainty  of  the 
+                magnitude.   If  multiple concentric apertures are used,
+                a magnitude and uncertainty shall be given for each.
+
+    (5) The program shall be usable  both  interactively  and  in  batch
+        mode.   In  interactive  use, the user shall be able to mark the
+        positions of the objects by interactively positioning  a  cursor
+        on  a  2-dim  display device.  It shall be possible to enter the
+        control parameters for the analysis routines  interactively  for
+        each  object.   In  batch  mode, the control parameters shall be
+        fixed, and  object  coordinates  shall  be  taken  from  a  user
+        supplied  list.   The  display  device  shall not be required in
+        batch mode.
+
+    (6) The APPHOT package shall be  written  in  the  SPP  language  in
+        conformance  with  the  standards  and conventions of IRAF.  The
+        code shall be portable and device independent.
+
+
+
+2.1 Summary of the Limitations of APPHOT
+
+    The  APPHOT  package  is  designed  to   perform   simple   aperture 
+photometry subject to the following restrictions:
+
+    (1) Objects   must   be  circular  or  nearly  circular,  since  the 
+
+
+                                  -2-
+APPHOT (Aug83)    Digital Aperture Photometry Package     APPHOT (Aug83)
+
+
+
+        aperture is circular.
+
+    (2) All pixels within the  object  aperture  are  weighted  equally.
+        All  pixels  in  the object aperture must be present; the object
+        aperture may not normally extend outside the  image.   Defective
+        pixels within the object aperture may not be detected.
+
+    (3) The  background  must  be approximately flat in the neighborhood
+        of the object  being  measured.   The  background  must  have  a
+        unique  mode,  or the background fitting routine will reject the
+        object.   Any  low  frequency  fluctuations  in  the  background 
+        should be removed before using APPHOT.
+
+    (4) The   object  aperture  must  be  kept  small  to  minimize  the 
+        degradation of signal to noise caused by sky pixels  within  the
+        aperture,  and  to minimize the effects of crowding.  Therefore,
+        the wings of the object will extend beyond the  aperture.   Good
+        photometric  results  will  be  obtained only if the aperture is
+        consistently well centered, and if the  shape  and  diameter  of
+        an  object  is  constant throughout the image and invariant with
+        respect to magnitude.
+
+
+
+3. Specifications
+
+    The  APPHOT  package  performs  aperture  photometry  on   digitized 
+starfields   maintained  as  IRAF  imagefiles.   Input  to  the  package 
+consists of an imagefile, a list of  object  coordinates,  and  numerous
+parameters  controlling  the  analysis  algorithms.   Output consists of
+successive lines of text, where each  line  summarizes  the  results  of
+the  analysis  for  a  particular  object.  The output may be saved in a
+textfile, which may easily be printed  or  written  onto  a  card  image
+tape   for   export.    The   package   routines   may  be  used  either 
+interactively or in batch mode.
+
+The CL callable part of the APPHOT package  consists  of  the  following
+routines:
+
+        apphot   -- the main aperture photometry routine.
+        coordtr  -- translations and rotations of coord lists.
+        fitsky   -- computes mode and sigma of a sky region.
+        fitpsf   -- compute the FWHM of the PSF.
+        imcursor -- reads the image cursor; used to make lists.
+        immark   -- marks objects on the display device.
+        radprof  -- computes the radial profile of an object.
+
+Routines  for  general list manipulation, reading and writing card image
+tapes,  reading  and  writing  images  to  FITS  tapes,   removing   the 
+instrumental   signature   from  the  data,  and  so  on  are  available 
+elsewhere in the  IRAF  system.   The  package  is  easily  extended  to
+include  peak  finding,  matching of object lists from different images,
+background fitting and removal, and so on.   The  APPHOT  package  shall
+
+
+                                  -3-
+APPHOT (Aug83)    Digital Aperture Photometry Package     APPHOT (Aug83)
+
+
+
+eventually   supplant   both   the  KPNO  AUTOPHOT  and  KPNO  "Mountain 
+Photometry Code" packages.
+
+
+
+3.1 Standard Analysis Procedures
+
+    Before performing aperture photometry one must determine the  radius
+of  the  object  aperture  to  be used, the inner radius and size of the
+annulus to be used to fit the background, the full  width  at  half  max
+(FWHM)  of  the  point  spread  function  (PSF),  and so on.  Additional
+parameters are required by the centering algorithm.  A  list  of  object
+centers  must  be  prepared  if APPHOT is to be used in batch mode.  The
+standard procedure is as follows:
+
+    (1) Use RADPROF to determine values for the following parameters:
+
+            - the object aperture radius or radii, in pixels
+            - the inner radius of the annular (sky) region
+            - the width of the annular region
+
+    (2) Use FITPSF to fit gaussians to isolated, high  signal  to  noise
+        data  objects,  to  determine  the  FWHM  of  the  point  spread 
+        function.
+
+    (3) Use FITSKY to determine  the  sky  sigma  (standard  deviation).
+        APPHOT  assumes  that sigma is approximately constant throughout
+        the image.
+
+    (4) If one does not wish to  manually  mark  object  positions  with
+        the  cursor  during  analysis,  i.e.  when the analysis is to be
+        done in batch, a list of object coordinates  must  be  prepared.
+        This may be done in many ways:
+
+            o   By  running  RCURSOR with the standard output redirected
+                into the list file.
+
+            o   By transforming an existing list with  COORDTR,  OPSTRM,
+                MATCH, SORT, WINDOW, the editor, or some other filter.
+
+            o   By  an  automatic  object  finding  procedure, if one is
+                available.
+
+            o   By any other program which generates a  list  of  object
+                coordinates,  where  each line of the list describes one
+                object, and where x  and  y  in  pixel  coordinates  are
+                given  in  columns  one and two.  Additional columns, if
+                present, are ignored.
+
+            o   APPHOT output may be  used  as  coordinate  input  in  a
+                subsequent run.
+
+    (5) Finally,  APPHOT  is  run  to  measure  the  objects.   The user
+
+
+                                  -4-
+APPHOT (Aug83)    Digital Aperture Photometry Package     APPHOT (Aug83)
+
+
+
+        should  be  familiar  with  the  algorithms  used  to  fit   the 
+        background,   measure   the   object  center,  and  compute  the 
+        aperture integral, magnitude, and errors.   The  values  of  all
+        visible   and  hidden  APPHOT  parameters  should  be  inspected 
+        before doing any serious processing.
+
+The general purpose IRAF list processing tools may be used  for  further
+analysis  of  APPHOT  output.   Output  lists  may be filtered to select
+objects based on the value of a  list  column,  i.e.,  all  the  objects
+within   a  certain  magnitude  range  may  be  selected,  objects  with 
+estimated errors larger than a certain value may be deleted, or  a  list
+may  be  sorted using the value in any column.  Columns may be extracted
+from a list to form new lists or to provide  input  to  a  plot  filter,
+and  lists  may  be  merged.   Arithmetic  may  be performed on lists to
+calculate colors, etc.
+
+The remainder of this section presents detailed specifications  for  the
+analysis procedures in the APPHOT package.
+
+
+
+3.2 The APPHOT Program
+
+    The  function  of  the  APPHOT  procedure  is  to  perform  aperture 
+photometry on isolated objects within an  image.   The  principal  input
+operands  are  the  name  of  the imagefile and the rough coordinates of
+the objects to be processed.  The  principal  output  operands  are  the
+coordinates and magnitudes of the objects.
+
+In  order  to  perform  aperture  photometry  APPHOT  must  perform  the 
+following  sequence  of  operations   (the   algorithms   employed   are 
+explained in more detail later in this section):
+
+    (1) The  mode  and sigma of an annular background region centered on
+        the object is calculated.
+
+    (2) The center of the object is determined.
+
+    (3) The background is subracted  from  the  object,  and  the  total
+        flux within the object aperture or apertures is calculated.
+
+Steps  (1)  and (2) above are optional; the background and center may be
+determined externally, rather than by APPHOT, if desired.
+
+
+3.2.1 APPHOT parameters
+
+    APPHOT has quite a few parameters  due  to  the  complexity  of  the
+algorithms  employed.   All  data dependent parameters are query mode to
+ensure that they get set properly when a new image  is  processed.   The
+data  independent  algorithm control parameters are hidden mode, and are
+given reasonable default values.   The  names,  datatypes,  and  default
+values of the APPHOT parameters are shown below.
+
+
+                                  -5-
+APPHOT (Aug83)    Digital Aperture Photometry Package     APPHOT (Aug83)
+
+
+
+Positional or query mode parameters:
+
+        image           filename
+        apertures       string
+        annulus         real
+        width_annulus   real
+        fwhm_psf        real
+        sky_sigma       real
+
+
+List structured parameters (filename may be given on command line):
+
+        sky_mode        *real
+        coords          *imcur
+
+
+Hidden parameters:
+
+        spool           boolean         no
+        output          filename        "apphot.out"
+        fitsky          boolean         yes
+        max_sky_iter    integer         50
+        growing_radius  real            1.0 (fwhm_psf units)
+        k1              real            5.0
+        k2              real            2.0
+        center          boolean         yes
+        clean           boolean         yes
+        cleaning_radius real            0.8 (fwhm_psf units)
+        clipping_radius real            1.5 (fwhm_psf units)
+        max_cen_shift   real            1.0 (fwhm_psf units)
+        min_snratio     real            0.5
+        zmag            real            26.0
+        verbose         boolean         yes
+
+
+The  function  and  format  of  each of these parameters is explained in
+more detail below.
+
+
+    image           The name  of  the  image  or  image  section  to  be
+                    processed.
+
+    output          The  name  of  the  output  textfile  used  to spool
+                    APPHOT  output.   If  null,  output  will   not   be 
+                    spooled.   Note  that  output  always appears on the
+                    standard output,  whether  or  not  spooling  is  in
+                    effect.
+
+    apertures       The   radii  in  pixels  of  the  concentric  object 
+                    apertures, given all on  the  same  line,  delimited
+                    by  blanks.   At  least  one aperture must be given;
+                    the maximum number of apertures is  limited  by  the
+                    length  of  a  line.  A sample input string might be
+
+
+                                  -6-
+APPHOT (Aug83)    Digital Aperture Photometry Package     APPHOT (Aug83)
+
+
+
+                    "5.0 5.5 6.0 6.5 7.0".  If only  a  single  aperture
+                    is  to  be  used,  a  real  expression  may  be used
+                    instead of a string type  argument.   The  apertures
+                    need  not  be  given  in  any particular order.  The
+                    average  radius  will  be  used   to   compute   the 
+                    uncertainty in the object magnitude.
+
+    annulus         The  inner  radius  of  the  annular  sky region, in
+                    pixels.
+
+    width_annulus   The width of the annular sky region, in pixels.
+
+    fwhm_psf        The FWHM of the psf, in pixels.   Used  as  a  scale
+                    factor to control the internal algorithms.
+
+    sky_sigma       The  standard  deviation  (noise value) of a typical
+                    region  of  sky  in  the  image.   Used  for   pixel 
+                    rejection in the sky fitting algorithm.
+
+    sky_mode        The  name  of a list file containing the mode of the
+                    background  of   each   of   the   objects   to   be 
+                    processed.   Required  only  if  FITSKY  is switched
+                    off.  If sky fitting is disabled, and no  list  file
+                    is given, APPHOT will query for the sky value.
+
+    coords          The  name  of a list file containing the coordinates
+                    of  the  objects  to  be  processed.    If   absent, 
+                    objects   may   be  marked  interactively  with  the 
+                    cursor.
+
+    fitsky          A  switch  used  to  specify  whether  or  not   the 
+                    background  will  be  fitted.  If background fitting
+                    is disabled, the mode and sigma  of  the  background
+                    will  be  read  from  the SKY_FILE list each time an
+                    object is processed.
+
+    max_sky_iter    The  maximum  number  of  iterations  for  the   sky 
+                    fitting    algorithm.    Since   the   sky   fitting  
+                    algorithm   is   guaranteed   to   converge,    this  
+                    parameter  should  normally  have a large value.  If
+                    the value is zero, the  median  of  the  sky  region
+                    will be used instead of the mode.
+
+    growing_radius  The  region  growing  radius  for pixel rejection in
+                    the sky region, in units of FWHM_PSF.   When  a  bad
+                    sky   pixel   is   detected,   all   pixels   within  
+                    (growing_radius  *  fwhm_psf)  pixels  of  the   bad 
+                    pixel  will  be rejected.  Used to exclude the wings
+                    of contaminating objects from  the  sky  sample,  to
+                    avoid biasing the mode.
+
+    k1              The  k-sigma  clipping factor for the first phase of
+                    the sky fitting algorithm.
+
+
+                                  -7-
+APPHOT (Aug83)    Digital Aperture Photometry Package     APPHOT (Aug83)
+
+
+
+    k2              The  k-sigma  clipping  factor   for   the   second, 
+                    iterative, phase of the sky fitting algorithm.
+
+    center          A  switch  used  to specify whether or not centering
+                    is to be performed.  If centering is  disabled,  the
+                    initial center will be used as the object center.
+
+    clean           A   switch  used  to  specify  whether  or  not  the 
+                    symmetry-clean algorithm is to  be  employed  during
+                    centering.
+
+    cleaning_radius The   cleaning   radius   for   the   symmetry-clean  
+                    algorithm, in units of FWHM_PSF.
+
+    clipping_radius The   clipping   radius   for   the   symmetry-clean  
+                    algorithm, in units of FWHM_PSF.
+
+    max_cen_shift   The  maximum  permissible  shift of center, in units
+                    of  FWHM_PSF.   If  the  shift   produced   by   the 
+                    centering  algorithm  is larger than this value, the
+                    fit  will  terminate  and  no  magnitude   will   be 
+                    calculated.
+
+    min_snratio     Centering  will  be  skipped  if the signal to noise
+                    of  the  object,  as  calculated  from  the  initial 
+                    center,  is  less  than  the  value  given  by  this 
+                    parameter.
+
+    zmag            Zero point for the output magnitude scale.
+
+    verbose         If enabled, the output columns  are  labeled.   Note
+                    that  the  presence  of  column labels in the output
+                    may interfere with the use of  the  list  processing
+                    tools.
+
+
+
+3.2.2 The APPHOT Background Fitting Algorithm
+
+    A  good background fit is essential to aperture photometry.  Fitting
+the background is trivial in a sparse field, but difficult in a  crowded
+field.   In  general  the  background  region will contain contaminating
+objects which must be detected and excluded if  a  good  fit  is  to  be
+obtained.
+
+The  algorithm  employed  here  is  based  on the fact that contaminated
+pixels are  almost  always  spatially  correlated.   Background  fitting
+algorithms  which  work with a one dimensional sample (mode, median), or
+with the  one  dimensional  histogram  (mode  of  hgm)  have  difficulty
+rejecting  the  faint  wings of contaminated regions.  This is a serious
+defect of one  dimensional  fitting  algorithms,  because  it  is  these
+faint  wings,  not  the  bright central pixels, which are most likely to
+bias the calculated background value.
+
+
+                                  -8-
+APPHOT (Aug83)    Digital Aperture Photometry Package     APPHOT (Aug83)
+
+
+
+The algorithm used in APPHOT is as follows:
+
+
+    algorithm fit_sky
+
+    begin
+            # Reject gross deviants.
+            compute the median of the annular region
+            detect pixels more than (k1*sky_sigma) from the median
+            reject all such pixels, without region growing
+
+            # Detect and reject contaminating objects.
+            while (number of iterations <= max_sky_iter) {
+                compute the histogram of the reduced sample
+                compute the sigma and mode of the histogram
+                detect pixels more than k2*sigma from the mode
+                reject all such pixels, with region growing
+                if (no pix rejected or all pix rejected)
+                    terminate loop
+            }
+
+            return the final mode, sigma, and sample size
+    end
+
+
+The mode of the histogram  is  found  by  cross  correlating  the  noise
+function  with  the  histogram.   The width of the the noise function is
+given  by  the  standard  deviation  of  the  current   sample.    Pixel 
+rejection  is  performed  by locating all pixels more than k2*sigma from
+the mode, and blindly rejecting all pixels within a  certain  radius  of
+each  deviant  pixel.   This  simple  algorithm  works  well because the
+sample is large, and therefore there is little  penalty  for  discarding
+pixels  that  might  not  be  deviant.   Region  growing  also  tends to
+accelerate convergence significantly.
+
+Very faint contaminating objects are difficult  to  detect  and  reject.
+If  there  are enough such objects, they should not be rejected, because
+there are probably a few in the object aperture as well.  A  higher  sky
+sigma  will  be calculated and the computed uncertainty in the magnitude
+will increase.  The best solution to this problem  may  be  to  increase
+the  size of the annulus to minimize the bias and maximize the liklihood
+of a detection.
+
+
+
+3.2.3 The APPHOT Centering Algorithm
+
+    The centering algorithm used in APPHOT  is  that  of  Auer  and  Van
+Altena,  with  the addition of the symmetry-clean algorithm developed by
+Barry Newell.  The main algorithm is as follows:
+
+
+
+
+
+                                  -9-
+APPHOT (Aug83)    Digital Aperture Photometry Package     APPHOT (Aug83)
+
+
+
+    algorithm get_center
+
+    begin
+            if (centering is disabled) {
+                return initial center, zero uncertainty estimate
+
+            } else if (signal to noise of object < MIN_SNRATIO) {
+                compute uncertainty using initial center
+                return initial center, computed uncertainty
+
+            } else {
+                call measure_center
+                return image center and estimated uncertainty
+            }
+    end
+
+
+The  actual  center  determination  is  carried  out  by  the  following 
+algorithm:
+
+
+    algorithm measure_center
+
+    begin
+            extract subarray from the main data array
+
+            # Perform symmetry-cleaning.
+            if (cleaning is enabled) {
+                for (each pair of pixels diametrically opposed about
+                    the image center beyond the cleaning radius)
+                        if (i2 > i1 + 2*sky_sigma)
+                            replace i2 by i1
+                        else if (i1 > i2 + 2*sky_sigma)
+                            replace i1 by i2
+
+                perform 2*sky_sigma noniterative clip of all pixels
+                beyond the clipping radius, to remove any remaining
+                radially symmetric structures
+            }
+
+            # Compute the image center and uncertainty.
+            compute x and y marginals of the cleaned subarray
+            fit a gaussian of width FWHM_PSF to each marginal
+            compute the centering error from the covariance matrix
+
+            return image center and estimated uncertainty
+    end
+
+
+The  effect  of  the  symmetry-clean  algorithm  is  to edit the raster,
+removing any contaminating  objects  in  the  vicinity  of  the  primary
+object.   This  simplifies  the  fitting  algorithm  and  increases  its 
+reliability, since it does not have  to  deal  with  multipeak  marginal
+
+
+                                 -10-
+APPHOT (Aug83)    Digital Aperture Photometry Package     APPHOT (Aug83)
+
+
+
+distributions.
+
+A  gaussian  is  fitted  to  the  marginal  distributions  because it is
+expected  to  yield  a  better  center  determination  for  undersampled 
+data.    An   alternative   is   to   empirically  derive  the  marginal 
+distributions of the psf and fit these to each data object.  This  is  a
+better  approach  in some cases, but in the case of undersampled data it
+is difficult to  derive  the  marginal  distributions  due  to  sampling
+effects,  and  fitting is difficult due to interpolation error.  The use
+of  a  gaussian  eliminates  interpolation  error.    Eventually,   both 
+techniques should be made available.
+
+
+
+3.2.4 The APPHOT Aperture Integration Algorithm
+
+    The  integral  of the flux within a circular aperture is computed by
+fractional pixel techniques.  Pixels are assumed to be square  apertures
+arranged  in  a  rectangular  grid.   The fraction of a pixel which lies
+within the circular APPHOT aperture is  computed  by  an  approximation,
+and all such contributions are summed to produce the total integral.
+
+The  simplicity  of aperture photometry limits the amount of information
+available for error analysis.   Using  only  the  noise  value  for  the
+background, the estimated error in the aperture integral is given by
+
+        flux_error = sky_sigma * sqrt (aperture_area)
+
+where  "sky_sigma"  is  either  the  sigma  calculated by the background
+fitting algorithm or the parameter SKY_SIGMA, depending on  whether  sky
+fitting  is  enabled,  and where "aperture_area" is the fractional pixel
+area of the aperture.
+
+It is possible, however, to produce a more useful error estimate  if  we
+include  some  information  about  the  psf.   For  the  purposes  of an
+improved error estimate, we assume that the PSF is  a  gaussian.   Given
+the  object  center,  the  background,  and  the  FWHM of the PSF, it is
+trivial to fit a two dimensional gaussian to the  object.   An  estimate
+of  the  average noise value for the pixels within the aperture may then
+be obtained by computing the standard deviation of the  residual  formed
+by  subtracting  the  fitted  two-dimensional  gaussian  from  the data.
+This value is used in place of SKY_SIGMA in the above  equation  for  an
+improved estimate of the actual flux error.
+
+In  the  limit  as the gaussian goes to zero, both uncertainty estimates
+tend to the same  value,  as  they  should.   For  bright  objects,  the
+uncertainty  produced  by  analysis  of  the  residual  will  tend to be
+pessimistic, since it is unlikely that the PSF can actually  be  modeled
+by  a  simple  gaussian.   Nonetheless,  a  plot  of  uncertainty versus
+magnitude should reveal objects which are  blended,  which  contain  bad
+pixels,  and  so  on.  The accuracy of the gaussian model will determine
+how reliably deviant objects can be discriminated.
+
+
+
+                                 -11-
+APPHOT (Aug83)    Digital Aperture Photometry Package     APPHOT (Aug83)
+
+
+
+3.2.5 APPHOT Output
+
+    For each object processed, APPHOT prints a single line  of  text  on
+the  standard  output.   If  desired,  APPHOT  will simultaneously spool
+output into a user specified text file.  Each output line  will  contain
+the following information (excluding the commas):
+
+
+    x,y,cenerr,shift, mode,sigma,nskypix, mag1,...,magn,magerr
+
+where
+
+    x,y         object coordinates in pixels
+    cenerr      estimated uncertainty in the object center
+    shift       shift of center from initial coordinates
+    mode        mode of the background
+    sigma       sigma of the background
+    nskypix     number of sky pixels left after rejection
+    mag1        magnitude within the first annulus
+    magn        magnitude within the Nth annulus
+    magerr      estimated mag. uncertainty at the average radius
+
+
+Note  that  the estimated uncertainty in the magnitude is given only for
+the average object aperture  radius.   The  uncertainty  for  the  other
+apertures  can  easily  be  calculated  given SIGMA and the area of each
+aperture.  The zero point for  the  magnitude  scale  is  given  by  the
+hidden parameter ZMAG.
+
+Additional  information  could  be  calculated  and  output (such as the
+moments of the object and the  skew  of  the  background),  but  in  our
+experience  few people ever look at such information, and a more complex
+output format would be required.  Probably the calculation  of  anything
+but  object  centers,  magnitudes,  and  errors  should be left to other
+programs.
+
+
+
+3.3 The COORDTR Program
+
+    The function of COORDTR is to effect  a  linear  translation  and/or
+rotation  of  a  coordinate list.  COORDTR is a filter; coordinate lines
+are read from the standard input and written  to  the  standard  output.
+COORDTR  is  concerned  only  with coordinate transformations, and knows
+nothing about image boundaries.  A transformed coordinate may no  longer
+lie within an image.
+
+        x y other_stuff
+
+The  format  of a coordinate line is shown above.  COORDTR operates only
+on the coordinate pair x,y.  Any additional information on the  line  is
+passed on to the output without modification.
+
+
+
+                                 -12-
+APPHOT (Aug83)    Digital Aperture Photometry Package     APPHOT (Aug83)
+
+
+
+COORDTR  is  actually  a  general  purpose list processing operator, and
+belongs in  a  list  processing  package,  rather  than  in  the  APPHOT
+package.   When  a list processing package is developed, COORDTR will be
+moved to that package.
+
+A COORDTR transformation consists of a linear  translation  followed  by
+a  rotation.   Either  the  translation,  the  rotation,  or both may be
+skipped.  The COORDTR parameters are summarized below.
+
+
+positional arguments:
+
+        xshift          real
+        yshift          real
+        xcenter         real
+        ycenter         real
+        theta           real
+
+
+hidden parameters:
+
+        translate       boolean         yes
+        rotate          boolean         no
+
+
+If more than two positional arguments  are  given,  COORDTR  knows  that
+both  a  translation  and a rotation are desired.  Otherwise the boolean
+parameters TRANSLATE and ROTATE are read to  determine  what  additional
+parameters  are  needed.   Thus  a  simple  linear  translation  of +2.5
+pixels in X and -0.2 pixels in Y would be specified by the command
+
+        coordtr (2.5, -.2, < "input", > "output")
+
+which transforms the list in file "input", writing the output  into  the
+new file "output".
+
+If  a  rotation  is  desired, XCENTER, YCENTER, and THETA must be given.
+The first two parameters specify the  pixel  coordinates  of  the  point
+about  which  the rotation is to be performed, while THETA specifies the
+rotation angle in degrees.  Positive THETA produces  a  counterclockwise
+rotation, if positive X is to the right and positive Y is up.
+
+
+
+3.4 The FITSKY Program
+
+    The  function  of  the  FITSKY  program is to determine the mode and
+sigma of the specified annular  regions,  printing  the  results  (mode,
+sigma,  and  npix)  on  the  standard  output.   FITSKY  is  similar  in 
+operation to APPHOT, except  that  its  function  is  to  fit  sky,  not
+perform aperture photometry.  The FITSKY parameters are the following:
+
+
+
+
+                                 -13-
+APPHOT (Aug83)    Digital Aperture Photometry Package     APPHOT (Aug83)
+
+
+
+Positional or query mode parameters:
+
+        image           filename
+        annulus         real
+        width_annulus   real
+        fwhm_psf        real
+
+
+List structured parameters (filename may be given on command line):
+
+        coords          *imcur
+
+
+Hidden parameters:
+
+        spool           boolean         no
+        output          filename        "fitsky.out"
+        max_sky_iter    integer         50
+        growing_radius  real            1.0 (fwhm_psf units)
+        k1              real            5.0
+        k2              real            2.0
+        verbose         boolean         yes
+
+
+The  names  and functions of the FITSKY parameters are the same as those
+for APPHOT.  Note that ANNULUS  may  be  set  to  zero  to  measure  the
+background   within   a   circular  aperture.   The  maximum  number  of 
+iterations may be set to zero to measure the median of the  sky  sample.
+FITSKY output may be spooled into a file and used as input to APPHOT.
+
+
+
+3.5 The FITPSF Program
+
+    The  function  of the FITPSF program is to determine the FWHM of the
+point spread function.  This is done  by  selecting  an  isolated,  high
+signal  to  noise  object,  computing the x and y marginal profiles, and
+fitting a gaussian to each  profile.   Output  consists  of  the  object
+center,  the  error in the center, and the FWHM of the fitted gaussians.
+Note that the sigma of a gaussian may be obtained by dividing  the  FWHM
+by 2.354.
+
+        x y err x_fwhm y_fwhm
+
+The input parameters for the FITPSF program are shown below.
+
+
+
+
+
+
+
+
+
+
+                                 -14-
+APPHOT (Aug83)    Digital Aperture Photometry Package     APPHOT (Aug83)
+
+
+
+Positional parameters:
+
+        image           filename
+        aperture        real
+        annulus         real
+        width_annulus   real
+        sky_mode        real
+        coords          *imcur
+
+
+Hidden parameters:
+
+        fitsky          boolean         yes
+        center          boolean         yes
+        spool           boolean         no
+        output          filename        "fitpsf.out"
+        verbose         boolean         yes
+
+
+If  background  fitting  is disabled, the parameter SKY_MODE defines the
+sky  level.   The  background  fitting  algorithm  is  a  simple  median 
+calculation  without  pixel  rejection  or  iteration.   This  should be
+sufficient, since FITPSF is expected to  be  used  mainly  in  uncrowded
+regions on high signal to noise objects.
+
+Note  that  FITPSF  is  set  up to process a list of input objects.  The
+list processing tools  (i.e.,  AVERAGE)  may  be  used  to  average  the
+results to produce the final FWHM of the PSF for the image.
+
+
+
+3.6 The IMCURSOR Program
+
+    The  function  of  the  IMCURSOR  program  is  to  read the STDIMAGE
+cursor, writing the cursor coordinates  on  the  standard  output.   The
+cursor  is  read  until  the  EOF  character is entered to terminate the
+loop.  The standard output may be redirected into a file to  generate  a
+coordinate list.  IMCURSOR has no parameters.
+
+
+
+3.7 The IMMARK Program
+
+    The  function  of  IMMARK  is  to  draw  marks on the diplay device.
+IMMARK is useful for verifying coordinate lists.
+
+
+parameters:
+
+        mark_type       string
+        mark_size       real
+        coords          *imcur
+
+
+
+                                 -15-
+APPHOT (Aug83)    Digital Aperture Photometry Package     APPHOT (Aug83)
+
+
+
+Output is  the  current  frame  of  the  STDIMAGE  device.   Mark  types
+include  "circle",  "box",  "cross", "plus", and "diamond".  The size of
+a  mark  is  given  in  pixels.   The  third  parameter  is  a  standard 
+coordinate  list.   If  no  list is given, the image cursor will be read
+instead.
+
+
+
+3.8 The RADPROF Program
+
+    The function of  the  RADPROF  program  is  to  compute  the  radial
+profile  of  an object.  The output of RADPROF consists of a sequence of
+lines of text, each line  defining  the  profile  at  a  single  radius.
+Since  RADPROF  may  generate  many  lines  of output for a single input
+object, it is set up to process  only  a  single  input  object.   A  CL
+while loop may be written to process multiple objects, if desired.
+
+
+positional arguments:
+
+        image           filename
+        aperture        real
+        step_size       real
+        annulus         real
+        width_annulus   real
+        sky_mode        real
+
+
+hidden parameters:
+
+        fitsky          boolean         yes
+        center          boolean         yes
+        verbose         boolean         yes
+
+
+The  radial  profile  is  calculated  from  the  image center out to the
+radius specified by  the  parameter  APERTURE,  in  steps  of  STEP_SIZE
+pixels.   The  remaining  RADPROF  parameters  are  similar  to those of
+APPHOT and will not be discussed in detail.  If  background  fitting  is
+disabled,   the   parameter   SKY_MODE   defines  the  sky  level.   The 
+background fitting algorithm is  a  simple  median  calculation  without
+pixel   rejection  or  iteration.   This  should  be  sufficient,  since 
+RADPROF is expected to be used  mainly  in  uncrowded  regions  on  high
+signal  to  noise  objects.   Centering  is  via  gaussian  fits  to the
+marginal profiles, without cleaning.
+
+RADPROF output lines contain the following fields:
+
+        r, i(r), inorm(r), fraction(r)
+
+where
+
+        r               radius in pixels
+
+
+                                 -16-
+APPHOT (Aug83)    Digital Aperture Photometry Package     APPHOT (Aug83)
+
+
+
+        i(r)            raw intensity at r
+        inorm(r)        normalized intensity at r (range 0-1)
+        fraction(r)     fraction of total integral at r
+
+
+RADPROF does not  generate  any  plots.   If  one  wishes  to  plot  the
+contents  of  an  output column, the column may be extracted with a list
+processing filter and piped to a graphics task.
+
+
+
+4.0 Example
+
+    A brief  example  may  help  illustrate  the  use  of  the  package.
+Suppose  we  want  to  process  a few hundred stars on images "blue" and
+"red".  We start by analyzing the blue image.
+
+        ap> radprof blue,15,0.5,20,10
+
+This gives us a radial profile printout for one  of  the  "blue"  stars.
+We  decide  that  an  aperture radius of 2.5 pixels is about right.  The
+annulus will start at a  radius  of  10.0  pixels  and  extend  to  20.0
+pixels.  The next step is to determine the FWHM of the PSF:
+
+        ap> fitpsf blue,3,10,20 | tee spoolfile
+
+By  default, the program will take coordinate input by reading the image
+display cursor.  When the program is waiting for cursor input,  it  will
+cause  the display cursor to blink rapidly; normally the cursor does not
+blink.  One has to be aware of this, because no other prompt is  issued.
+We  postion  the  cursor  on  several  stars,  and  tap the space bar to
+measure each one.  When finished we type  the  EOF  character  (<ctrl/z>
+on  our  systems)  to terminate the loop.  The screen will now look like
+this (the output column labels are ommitted):
+
+        ap> fitpsf blue,3,10,20 | tee spoolfile
+         283.12  157.40 0.035  2.887  2.751
+         546.08  213.45 0.023  2.833  2.902
+         318.32  354.73 0.064  2.791  2.824
+
+Since we elected to use TEE to spool the output, rather than  the  SPOOL
+parameter  of  FITPSF,  we will not see the results until all stars have
+been measured.  The next step is to average the  results,  to  determine
+the  final  FWHM  (the  FITPSF  output could have been piped directly to
+GETCOLS without using an intermediate spoolfile, if desired).
+
+        ap> getcols spoolfile,"4-5" | getcols | average
+        2.83133 0.0569725 6 
+
+There are many ways this average could have been  computed,  of  course;
+this  is  only  one  example.   Next,  to avoid having to write down the
+FWHM value, we put it into the appropriate APPHOT parameter  (note  that
+the parameter name is abbreviated).
+
+
+                                 -17-
+APPHOT (Aug83)    Digital Aperture Photometry Package     APPHOT (Aug83)
+
+
+
+        ap> apphot.fwhm = 2.831
+
+Finally,  we  must  determine a representative backround sigma value for
+the image.  This is done by using FITSKY to measure several  sky  areas,
+and  averaging column two of the output, much as we did for FITPSF.  The
+final value may be saved in "apphot.sky_sigma".
+
+By this point we have determined all the necessary  parameters,  and  it
+is  time  to  do  some photometry.  The only APPHOT argument we are sure
+of is the image name parameter,  so  that  is  all  we  include  on  the
+command line:
+
+        ap> apphot blue
+        aperture radii, pixels: 2.4 2.5 2.75 3.0
+        inner radius of sky annulus: 10
+        width of sky annulus (1 - ): 10
+        full width at half max of psf (2.831):
+        standard deviation of the image noise function (23.733):
+
+After  responding  to  the  prompts shown above, APPHOT will ask for the
+first pair of object coordinates,  and  the  cursor  blink  prompt  will
+again  be  given.  Several objects may be measured to verify that all is
+working.
+
+The last step is to prepare a list of  objects  to  be  processed.   The
+simplest  way  to  do this is to interactively mark the objects with the
+cursor.  Later, when we process the "red"  image,  the  same  coordinate
+list may again be used, possibly after filtering with COORDTR.
+
+        ap> imcursor > objlist
+
+At  this  point,  all  of the APPHOT parameters have been set, we have a
+list of objects to be processed, and we  are  ready  to  run  APPHOT  in
+batch  mode.   We  decide to save the output in the file "blue.out".  To
+ensure that we have a record of the parameters  used  for  the  fit,  we
+first  print  the  APPHOT parameters into the output file, then we start
+up the APPHOT batch run.
+
+        ap> lparam apphot > blue.out
+        ap> apphot >> blue.out &
+        [1]
+
+The batch job is  now  running,  appending  output  lines  to  the  file
+"blue.out".   We  can  proceed  to  set up the job for the red image, in
+much the same way that we set up the  job  for  the  blue  image.   When
+both  jobs  finish,  we  can use the list processing tools to filter out
+the good objects and calculate colors.
diff --git a/noao/digiphot/apphot/doc/specs/Ap.spc b/noao/digiphot/apphot/doc/specs/Ap.spc
new file mode 100644
index 00000000..911d04f1
--- /dev/null
+++ b/noao/digiphot/apphot/doc/specs/Ap.spc
@@ -0,0 +1,1032 @@
+.help apphot Aug83 "Digital Aperture Photometry Package"
+.sh
+1. Introduction
+
+    The APPHOT package will provide a set of routines for performing
+aperture photometry on uncrowded or moderately crowded fields, in either
+interactive or batch mode.  The basic photometry technique employed
+shall be fractional-pixel aperture integration; no PSF fitting techniques
+shall be employed, and no knowledge of the PSF shall be required.
+This document presents the formal requirements and specifications for
+the package, and describes the algorithms to be used.
+
+.sh
+2. Requirements
+.ls 4
+.ls (1)
+The program shall take as input an IRAF imagefile containing a starfield
+which has been corrected for pixel to pixel gain variations, high frequency
+fluctuations in the background, nonlinearity, and any other instrumental
+defects affecting the intensity value of a pixel.
+.le
+.ls (2)
+Given as input the approximate coordinates of a single object in the image,
+the program shall perform the following operations:
+.ls 4
+.ls o
+Determine a constant background value by analysis of an annular region
+surrounding the object.  The background is assumed to be flat in the region
+of the object, but may contain contaminating objects or defects which
+shall be detected and eliminated by the fitting algorithm.
+It shall be permissible for the background region to extend beyond the
+boundaries of the image; the out of bounds region of the annulus shall
+be excluded from the fit.
+.le
+.ls o
+Determine the center of the object, taking the approximate object
+coordinates given as input as a starting point.
+The center determination shall be resistant to the affects of nearby
+contaminating objects.  The centering algorithm may assume that the object
+is circularly symmetric, or nearly so, and that the object flux is positive.
+.le
+.ls o
+Determine the integral of object minus background within one or more
+circular apertures centered upon the object.  The integration shall be
+performed using partial pixel techniques, to minimize the effects of
+sampling.  If the aperture contains any indefinite pixels, or if the
+aperture extends beyond the boundary of the image, an indefinite result
+shall be returned.
+.le
+.le
+.le
+.ls (3)
+The following options shall be provided to modify the operation of the
+above functions:
+.ls
+.ls o
+Use a user supplied constant background value and background noise estimate
+instead of fitting the background.
+.le
+.ls o
+Use the starting center as the actual center in all cases.
+.le
+.ls o
+Use the starting center as the actual center if the object is very faint,
+but tweak up the center if the signal to noise is above a certain threshold.
+.le
+.ls o
+Allow the object aperture to extend beyond the image boundary,
+using only that portion of the aperture which is in bounds when computing
+the aperture integral.
+.le
+.le
+.le
+.ls (4)
+At a minimum, the following parameters shall be calculated and output
+for each object:
+.ls
+.ls o
+The coordinates of the object, and the estimated error in these coordinates.
+.le
+.ls o
+The mode and standard deviation of the background; the number of pixels
+left in the background region after pixel rejection.
+.le
+.ls o
+The magnitude of the object, to within an arbitary zero-point, and
+the statistical uncertainty of the magnitude.  If multiple concentric
+apertures are used, a magnitude and uncertainty shall be given for each.
+.le
+.le
+.le
+.ls (5)
+The program shall be usable both interactively and in batch mode.
+In interactive use, the user shall be able to mark the positions of the
+objects by interactively positioning a cursor on a 2-dim display device.
+It shall be possible to enter the control parameters for the analysis
+routines interactively for each object.  In batch mode, the control
+parameters shall be fixed, and object coordinates shall be taken from
+a user supplied list.  The display device shall not be required in
+batch mode.
+.le
+.ls (6)
+The APPHOT package shall be written in the SPP language in conformance
+with the standards and conventions of IRAF.  The code shall be portable
+and device independent.
+.le
+.le
+
+.sh
+2.1 Summary of the Limitations of APPHOT
+
+    The APPHOT package is designed to perform simple aperture photometry
+subject to the following restrictions:
+.ls
+.ls (1)
+Objects must be circular or nearly circular, since the aperture is
+circular.
+.le
+.ls (2)
+All pixels within the object aperture are weighted equally.  All pixels
+in the object aperture must be present; the object aperture may not normally
+extend outside the image.  Defective pixels within the object
+aperture may not be detected.
+.le
+.ls (3)
+The background must be approximately flat in the neighborhood of the
+object being measured.  The background must have a unique mode,
+or the background fitting routine will reject the object.  Any low
+frequency fluctuations in the background should be removed before
+using APPHOT.
+.le
+.ls (4)
+The object aperture must be kept small to minimize the degradation of
+signal to noise caused by sky pixels within the aperture, and to
+minimize the effects of crowding.  Therefore, the wings of the object
+will extend beyond the aperture.  Good photometric results will be
+obtained only if the aperture is consistently well centered, and if the
+shape and diameter of an object is constant throughout the image and
+invariant with respect to magnitude.
+.le
+.le
+
+.sh
+3. Specifications
+
+    The APPHOT package performs aperture photometry on digitized starfields
+maintained as IRAF imagefiles.  Input to the package consists of an imagefile,
+a list of object coordinates, and numerous parameters controlling the analysis
+algorithms.  Output consists of successive lines of text, where each line
+summarizes the results of the analysis for a particular object.  The output
+may be saved in a textfile, which may easily be printed or written onto a
+card image tape for export.  The package routines may be used either
+interactively or in batch mode.
+
+The CL callable part of the APPHOT package consists of the following
+routines:
+
+.ks
+.nf
+	apphot	 -- the main aperture photometry routine.
+	coordtr	 -- translations and rotations of coord lists.
+	fitsky	 -- computes mode and sigma of a sky region.
+	fitpsf	 -- compute the FWHM of the PSF.
+	imcursor -- reads the image cursor; used to make lists.
+	immark	 -- marks objects on the display device.
+	radprof	 -- computes the radial profile of an object.
+.fi
+.ke
+
+Routines for general list manipulation, reading and writing card image tapes,
+reading and writing images to FITS tapes, removing the instrumental signature
+from the data, and so on are available elsewhere in the IRAF system.
+The package is easily extended to include peak finding,
+matching of object lists from different images,
+background fitting and removal, and so on.  The APPHOT package shall eventually
+supplant both the KPNO AUTOPHOT and KPNO "Mountain Photometry Code" packages.
+
+.sh
+3.1 Standard Analysis Procedures
+
+    Before performing aperture photometry one must determine the radius
+of the object aperture to be used, the inner radius and size of the annulus
+to be used to fit the background, the full width at half max (FWHM) of
+the point spread function (PSF), and so on.
+Additional parameters are required by the centering algorithm.
+A list of object centers must be prepared if APPHOT is to be used in
+batch mode.  The standard procedure is as follows:
+.ls
+.ls (1)
+Use RADPROF to determine values for the following parameters:
+
+.nf
+    - the object aperture radius or radii, in pixels
+    - the inner radius of the annular (sky) region
+    - the width of the annular region
+.fi
+.le
+.ls (2)
+Use FITPSF to fit gaussians to isolated, high signal to noise data objects,
+to determine the FWHM of the point spread function.
+.le
+.ls (3)
+Use FITSKY to determine the sky sigma (standard deviation).
+APPHOT assumes that sigma is approximately constant throughout the image.
+.le
+.ls (4)
+If one does not wish to manually mark object positions with the cursor
+during analysis, i.e. when the analysis is to be done in batch, a list
+of object coordinates must be prepared.  This may be done in many ways:
+.ls
+.ls o
+By running RCURSOR with the standard output redirected into the list file.
+.le
+.ls o
+By transforming an existing list with COORDTR, OPSTRM, MATCH, SORT, WINDOW,
+the editor, or some other filter.
+.le
+.ls o
+By an automatic object finding procedure, if one is available.
+.le
+.ls o
+By any other program which generates a list of object coordinates,
+where each line of the list describes one object, and where x and y
+in pixel coordinates are given in columns one and two.  Additional
+columns, if present, are ignored.
+.le
+.ls o
+APPHOT output may be used as coordinate input in a subsequent run.
+.le
+.le
+.le
+.ls (5)
+Finally, APPHOT is run to measure the objects.  The user should be familiar
+with the algorithms used to fit the background, measure the object center,
+and compute the aperture integral, magnitude, and errors.  The values of
+all visible and hidden APPHOT parameters should be inspected before doing
+any serious processing.
+.le
+.le
+
+The general purpose IRAF list processing tools may be used for further
+analysis of APPHOT output.
+Output lists may be filtered to select objects based on the value of a
+list column, i.e., all the objects within a certain magnitude range may
+be selected, objects with estimated errors larger than a certain value
+may be deleted, or a list may be sorted using the value in any column.
+Columns may be extracted from a list to form new lists or to provide input
+to a plot filter, and lists may be merged.
+Arithmetic may be performed on lists to calculate colors, etc.
+
+The remainder of this section presents detailed specifications for the analysis
+procedures in the APPHOT package.
+
+.sh
+3.2 The APPHOT Program
+
+    The function of the APPHOT procedure is to perform aperture photometry
+on isolated objects within an image.  The principal input operands are the 
+name of the imagefile and the rough coordinates of the objects to be processed.
+The principal output operands are the coordinates and magnitudes of the
+objects.
+
+In order to perform aperture photometry APPHOT must perform the following
+sequence of operations (the algorithms employed are explained in
+more detail later in this section):
+.ls
+.ls (1)
+The mode and sigma of an annular background region centered on the object
+is calculated.
+.le
+.ls (2)
+The center of the object is determined.
+.le
+.ls (3)
+The background is subracted from the object, and the total flux within
+the object aperture or apertures is calculated.
+.le
+.le
+
+Steps (1) and (2) above are optional; the background and center may be
+determined externally, rather than by APPHOT, if desired.
+.sh
+3.2.1 APPHOT parameters
+
+    APPHOT has quite a few parameters due to the complexity of the
+algorithms employed.  All data dependent parameters are query mode to
+ensure that they get set properly when a new image is processed.
+The data independent algorithm control parameters are hidden mode,
+and are given reasonable default values.  The names, datatypes, and
+default values of the APPHOT parameters are shown below.
+
+
+.ks
+.nf
+Positional or query mode parameters:
+
+	image		filename
+	apertures	string
+	annulus		real
+	width_annulus	real
+	fwhm_psf	real
+	sky_sigma	real
+.fi
+.ke
+
+
+.ks
+.nf
+List structured parameters (filename may be given on command line):
+
+	sky_mode	*real
+	coords		*imcur
+.fi
+.ke
+
+
+.ks
+.nf
+Hidden parameters:
+
+	spool		boolean		no
+	output		filename	"apphot.out"
+	fitsky		boolean		yes
+	max_sky_iter	integer		50
+	growing_radius	real		1.0 (fwhm_psf units)
+	k1		real		5.0
+	k2		real		2.0
+	center		boolean		yes
+	clean		boolean		yes
+	cleaning_radius	real		0.8 (fwhm_psf units)
+	clipping_radius	real		1.5 (fwhm_psf units)
+	max_cen_shift	real		1.0 (fwhm_psf units)
+	min_snratio	real		0.5
+	zmag		real		26.0
+	verbose		boolean		yes
+.fi
+.ke
+
+
+The function and format of each of these parameters is explained in more
+detail below.
+
+.ls
+.ls 16 image
+The name of the image or image section to be processed.
+.le
+.ls output
+The name of the output textfile used to spool APPHOT output.
+If null, output will not be spooled.  Note that output always appears on
+the standard output, whether or not spooling is in effect.
+.le
+.ls apertures
+The radii in pixels of the concentric object apertures, given all on the
+same line, delimited by blanks.  At least one aperture must be given;
+the maximum number of apertures is limited by the length of a line.
+A sample input string might be "5.0 5.5 6.0 6.5 7.0".  If only a single
+aperture is to be used, a real expression may be used instead of a string
+type argument.  The apertures need not be given in any particular order.
+The average radius will be used to compute the uncertainty in the
+object magnitude.
+.le
+.ls annulus
+The inner radius of the annular sky region, in pixels.
+.le
+.ls width_annulus
+The width of the annular sky region, in pixels.
+.le
+.ls fwhm_psf
+The FWHM of the psf, in pixels.  Used as a scale factor to control the
+internal algorithms.
+.le
+.ls sky_sigma
+The standard deviation (noise value) of a typical region of sky in
+the image.  Used for pixel rejection in the sky fitting algorithm.
+.le
+.ls sky_mode
+The name of a list file containing the mode of the background of each of
+the objects to be processed.  Required only if FITSKY is switched off.
+If sky fitting is disabled, and no list file is given, APPHOT will query
+for the sky value.
+.le
+.ls coords
+The name of a list file containing the coordinates of the objects to
+be processed.  If absent, objects may be marked interactively with the
+cursor.
+.le
+.ls fitsky
+A switch used to specify whether or not the background will be fitted.
+If background fitting is disabled, the mode and sigma of the background
+will be read from the SKY_FILE list each time an object is processed.
+.le
+.ls max_sky_iter
+The maximum number of iterations for the sky fitting algorithm.
+Since the sky fitting algorithm is guaranteed to converge,
+this parameter should normally have a large value.  If the value
+is zero, the median of the sky region will be used instead of the mode.
+.le
+.ls growing_radius
+The region growing radius for pixel rejection in the sky region, in units
+of FWHM_PSF.  When a bad sky pixel is detected, all pixels within
+(growing_radius * fwhm_psf) pixels of the bad pixel will be rejected.
+Used to exclude the wings of contaminating objects from the sky sample,
+to avoid biasing the mode.
+.le
+.ls k1
+The k-sigma clipping factor for the first phase of the sky fitting algorithm.
+.le
+.ls k2
+The k-sigma clipping factor for the second, iterative, phase of the
+sky fitting algorithm.
+.le
+.ls center
+A switch used to specify whether or not centering is to be performed.
+If centering is disabled, the initial center will be used as the object center.
+.le
+.ls clean
+A switch used to specify whether or not the symmetry-clean algorithm
+is to be employed during centering.
+.le
+.ls cleaning_radius
+The cleaning radius for the symmetry-clean algorithm, in units of
+FWHM_PSF.
+.le
+.ls clipping_radius
+The clipping radius for the symmetry-clean algorithm, in units of
+FWHM_PSF.
+.le
+.ls max_cen_shift
+The maximum permissible shift of center, in units of FWHM_PSF.
+If the shift produced by the centering algorithm is larger than this value,
+the fit will terminate and no magnitude will be calculated.
+.le
+.ls min_snratio
+Centering will be skipped if the signal to noise of the object,
+as calculated from the initial center, is less than the value given
+by this parameter.
+.le
+.ls zmag
+Zero point for the output magnitude scale.
+.le
+.ls verbose
+If enabled, the output columns are labeled.  Note that the presence
+of column labels in the output may interfere with the use of the list
+processing tools.
+.le
+.le
+
+.sh
+3.2.2 The APPHOT Background Fitting Algorithm
+
+    A good background fit is essential to aperture photometry.  Fitting
+the background is trivial in a sparse field, but difficult in a crowded
+field.  In general the background region will contain contaminating objects
+which must be detected and excluded if a good fit is to be obtained.
+
+The algorithm employed here is based on the fact that contaminated pixels
+are almost always spatially correlated.  Background fitting algorithms
+which work with a one dimensional sample (mode, median), or with the one
+dimensional histogram (mode of hgm) have difficulty rejecting the faint
+wings of contaminated regions.  This is a serious defect of one dimensional
+fitting algorithms, because it is these faint wings, not the bright
+central pixels, which are most likely to bias the calculated background value.
+
+The algorithm used in APPHOT is as follows:
+
+
+.ks
+.nf
+    algorithm fit_sky
+
+    begin
+	    # Reject gross deviants.
+	    compute the median of the annular region
+	    detect pixels more than (k1*sky_sigma) from the median
+	    reject all such pixels, without region growing
+
+	    # Detect and reject contaminating objects.
+	    while (number of iterations <= max_sky_iter) {
+		compute the histogram of the reduced sample
+		compute the sigma and mode of the histogram
+		detect pixels more than k2*sigma from the mode
+		reject all such pixels, with region growing
+		if (no pix rejected or all pix rejected)
+		    terminate loop
+	    }
+
+	    return the final mode, sigma, and sample size
+    end
+.fi
+.ke
+
+
+The mode of the histogram is found by cross correlating the noise function
+with the histogram.  The width of the the noise function is given by the
+standard deviation of the current sample.  Pixel rejection is
+performed by locating all pixels more than k2*sigma from the mode,
+and blindly rejecting all pixels within a certain radius of each deviant
+pixel.  This simple algorithm works well because the sample is large,
+and therefore there is little penalty for discarding pixels that might
+not be deviant.  Region growing also tends to accelerate convergence
+significantly.
+
+Very faint contaminating objects are difficult to detect and reject.
+If there are enough such objects, they should not be rejected, because
+there are probably a few in the object aperture as well.  A higher sky
+sigma will be calculated and the computed uncertainty in the magnitude
+will increase.  The best solution to this problem may be to increase
+the size of the annulus to minimize the bias and maximize the liklihood
+of a detection.
+
+.sh
+3.2.3 The APPHOT Centering Algorithm
+
+    The centering algorithm used in APPHOT is that of Auer and Van Altena,
+with the addition of the symmetry-clean algorithm developed by Barry Newell.
+The main algorithm is as follows:
+
+
+.ks
+.nf
+    algorithm get_center
+
+    begin
+	    if (centering is disabled) {
+		return initial center, zero uncertainty estimate
+
+	    } else if (signal to noise of object < MIN_SNRATIO) {
+		compute uncertainty using initial center
+		return initial center, computed uncertainty
+
+	    } else {
+		call measure_center
+		return image center and estimated uncertainty
+	    }
+    end
+.fi
+.ke
+
+
+The actual center determination is carried out by the following
+algorithm:
+
+
+.ks
+.nf
+    algorithm measure_center
+
+    begin
+	    extract subarray from the main data array
+
+	    # Perform symmetry-cleaning.
+	    if (cleaning is enabled) {
+		for (each pair of pixels diametrically opposed about
+		    the image center beyond the cleaning radius)
+			if (i2 > i1 + 2*sky_sigma)
+			    replace i2 by i1
+			else if (i1 > i2 + 2*sky_sigma)
+			    replace i1 by i2
+
+		perform 2*sky_sigma noniterative clip of all pixels
+		beyond the clipping radius, to remove any remaining
+		radially symmetric structures
+	    }
+
+	    # Compute the image center and uncertainty.
+	    compute x and y marginals of the cleaned subarray
+	    fit a gaussian of width FWHM_PSF to each marginal
+	    compute the centering error from the covariance matrix
+
+	    return image center and estimated uncertainty
+    end
+.fi
+.ke
+
+
+The effect of the symmetry-clean algorithm is to edit the raster,
+removing any contaminating objects in the vicinity of the primary object.
+This simplifies the fitting algorithm and increases its reliability,
+since it does not have to deal with multipeak marginal distributions.
+
+A gaussian is fitted to the marginal distributions because it is expected
+to yield a better center determination for undersampled data.  
+An alternative is to empirically derive the marginal distributions of
+the psf and fit these to each data object.  This is a better approach in
+some cases, but in the case of undersampled data it is difficult to derive
+the marginal distributions due to sampling effects, and fitting is difficult
+due to interpolation error.  The use of a gaussian eliminates interpolation
+error.  Eventually, both techniques should be made available.
+
+.sh
+3.2.4 The APPHOT Aperture Integration Algorithm
+
+    The integral of the flux within a circular aperture is computed by
+fractional pixel techniques.  Pixels are assumed to be square apertures
+arranged in a rectangular grid.  The fraction of a pixel which lies within
+the circular APPHOT aperture is computed by an approximation, and all
+such contributions are summed to produce the total integral.
+
+The simplicity of aperture photometry limits the amount of information
+available for error analysis.  Using only the noise value for the background,
+the estimated error in the aperture integral is given by
+
+	flux_error = sky_sigma * sqrt (aperture_area)
+
+where "sky_sigma" is either the sigma calculated by the background fitting
+algorithm or the parameter SKY_SIGMA, depending on whether sky fitting
+is enabled, and where "aperture_area" is the fractional pixel area of the
+aperture.
+
+It is possible, however, to produce a more useful error estimate if we
+include some information about the psf.  For the purposes of an improved
+error estimate, we assume that the PSF is a gaussian.  Given the object center,
+the background, and the FWHM of the PSF, it is trivial to fit a two dimensional
+gaussian to the object.  An estimate of the average noise value for the
+pixels within the aperture may then be obtained by computing the standard
+deviation of the residual formed by subtracting the fitted two-dimensional
+gaussian from the data.  This value is used in place of SKY_SIGMA in the
+above equation for an improved estimate of the actual flux error.
+
+In the limit as the gaussian goes to zero, both uncertainty estimates tend
+to the same value, as they should.  For bright objects, the uncertainty
+produced by analysis of the residual will tend to be pessimistic, since
+it is unlikely that the PSF can actually be modeled by a simple gaussian.
+Nonetheless, a plot of uncertainty versus magnitude should reveal objects
+which are blended, which contain bad pixels, and so on.  The accuracy of
+the gaussian model will determine how reliably deviant objects can be
+discriminated.
+
+.sh
+3.2.5 APPHOT Output
+
+    For each object processed, APPHOT prints a single line of text on the
+standard output.  If desired, APPHOT will simultaneously spool output into
+a user specified text file.  Each output line will contain the following
+information (excluding the commas):
+
+
+.nf
+    x,y,cenerr,shift, mode,sigma,nskypix, mag1,...,magn,magerr
+
+where
+
+    x,y		object coordinates in pixels
+    cenerr	estimated uncertainty in the object center
+    shift	shift of center from initial coordinates
+    mode	mode of the background
+    sigma	sigma of the background
+    nskypix	number of sky pixels left after rejection
+    mag1	magnitude within the first annulus
+    magn	magnitude within the Nth annulus
+    magerr	estimated mag. uncertainty at the average radius
+.fi
+
+
+Note that the estimated uncertainty in the magnitude is given only for
+the average object aperture radius.  The uncertainty for the other
+apertures can easily be calculated given SIGMA and the area of each
+aperture.  The zero point for the magnitude scale is given by the
+hidden parameter ZMAG.
+
+Additional information could be calculated and output (such as the
+moments of the object and the skew of the background), but in our
+experience few people ever look at such information, and a more complex
+output format would be required.  Probably the calculation of anything
+but object centers, magnitudes, and errors should be left to other
+programs.
+
+.sh
+3.3 The COORDTR Program
+
+    The function of COORDTR is to effect a linear translation and/or
+rotation of a coordinate list.  COORDTR is a filter; coordinate lines
+are read from the standard input and written to the standard output.
+COORDTR is concerned only with coordinate transformations, and knows
+nothing about image boundaries.  A transformed coordinate may no longer
+lie within an image.
+
+	x y other_stuff
+
+The format of a coordinate line is shown above.  COORDTR operates only
+on the coordinate pair x,y.  Any additional information on the line is
+passed on to the output without modification.
+
+COORDTR is actually a general purpose list processing operator, and
+belongs in a list processing package, rather than in the APPHOT package.
+When a list processing package is developed, COORDTR will be moved to
+that package.
+
+A COORDTR transformation consists of a linear translation followed
+by a rotation.  Either the translation, the rotation, or both may be
+skipped.  The COORDTR parameters are summarized below.
+
+
+.ks
+.nf
+positional arguments:
+
+	xshift		real
+	yshift		real
+	xcenter		real
+	ycenter		real
+	theta		real
+.fi
+.ke
+
+
+.ks
+.nf
+hidden parameters:
+
+	translate	boolean		yes
+	rotate		boolean		no
+.fi
+.ke
+
+
+If more than two positional arguments are given, COORDTR knows
+that both a translation and a rotation are desired.  Otherwise the
+boolean parameters TRANSLATE and ROTATE are read to determine
+what additional parameters are needed.  Thus a simple linear translation
+of +2.5 pixels in X and -0.2 pixels in Y would be specified by the
+command
+
+	coordtr (2.5, -.2, < "input", > "output")
+
+which transforms the list in file "input", writing the output into the 
+new file "output".
+
+If a rotation is desired, XCENTER, YCENTER, and THETA must be given.
+The first two parameters specify the pixel coordinates of the point
+about which the rotation is to be performed, while THETA specifies
+the rotation angle in degrees.  Positive THETA produces a counterclockwise
+rotation, if positive X is to the right and positive Y is up.
+
+.sh
+3.4 The FITSKY Program
+
+    The function of the FITSKY program is to determine the mode and sigma
+of the specified annular regions, printing the results (mode, sigma, and npix)
+on the standard output.  FITSKY is similar in operation to APPHOT, except
+that its function is to fit sky, not perform aperture photometry.  The
+FITSKY parameters are the following:
+
+
+.ks
+.nf
+Positional or query mode parameters:
+
+	image		filename
+	annulus		real
+	width_annulus	real
+	fwhm_psf	real
+.fi
+.ke
+
+
+.ks
+.nf
+List structured parameters (filename may be given on command line):
+
+	coords		*imcur
+.fi
+.ke
+
+
+.ks
+.nf
+Hidden parameters:
+
+	spool		boolean		no
+	output		filename	"fitsky.out"
+	max_sky_iter	integer		50
+	growing_radius	real		1.0 (fwhm_psf units)
+	k1		real		5.0
+	k2		real		2.0
+	verbose		boolean		yes
+.fi
+.ke
+
+
+The names and functions of the FITSKY parameters are the same as those
+for APPHOT.  Note that ANNULUS may be set to zero to measure the
+background within a circular aperture.  The maximum number of iterations
+may be set to zero to measure the median of the sky sample.
+FITSKY output may be spooled into a file and used as input to APPHOT.
+
+.sh
+3.5 The FITPSF Program
+
+    The function of the FITPSF program is to determine the FWHM of the
+point spread function.  This is done by selecting an isolated, high
+signal to noise object, computing the x and y marginal profiles,
+and fitting a gaussian to each profile.  Output consists of the object
+center, the error in the center, and the FWHM of the fitted gaussians.
+Note that the sigma of a gaussian may be obtained by dividing the FWHM
+by 2.354.
+
+	x y err x_fwhm y_fwhm
+
+The input parameters for the FITPSF program are shown below.
+
+
+.ks
+.nf
+Positional parameters:
+
+	image		filename
+	aperture	real
+	annulus		real
+	width_annulus	real
+	sky_mode	real
+	coords		*imcur
+.fi
+.ke
+
+
+.ks
+.nf
+Hidden parameters:
+
+	fitsky		boolean		yes
+	center		boolean		yes
+	spool		boolean		no
+	output		filename	"fitpsf.out"
+	verbose		boolean		yes
+.fi
+.ke
+
+
+If background fitting is disabled, the parameter SKY_MODE defines
+the sky level.  The background fitting algorithm is a simple median
+calculation without pixel rejection or iteration.
+This should be sufficient, since FITPSF is expected to be used mainly
+in uncrowded regions on high signal to noise objects.
+
+Note that FITPSF is set up to process a list of input objects.
+The list processing tools (i.e., AVERAGE) may be used to average the
+results to produce the final FWHM of the PSF for the image.
+
+.sh
+3.6 The IMCURSOR Program
+
+    The function of the IMCURSOR program is to read the STDIMAGE cursor,
+writing the cursor coordinates on the standard output.  The cursor is read
+until the EOF character is entered to terminate the loop.  The standard
+output may be redirected into a file to generate a coordinate list.
+IMCURSOR has no parameters.
+
+.sh
+3.7 The IMMARK Program
+
+    The function of IMMARK is to draw marks on the diplay device.
+IMMARK is useful for verifying coordinate lists.
+
+
+.ks
+.nf
+parameters:
+
+	mark_type	string
+	mark_size	real
+	coords		*imcur
+.fi
+.ke
+
+
+Output is the current frame of the STDIMAGE device.  Mark types
+include "circle", "box", "cross", "plus", and "diamond".  The size of
+a mark is given in pixels.  The third parameter is a standard coordinate
+list.  If no list is given, the image cursor will be read instead.
+
+.sh
+3.8 The RADPROF Program
+
+    The function of the RADPROF program is to compute the radial profile
+of an object.  The output of RADPROF consists of a sequence of lines of
+text, each line defining the profile at a single radius.  Since RADPROF
+may generate many lines of output for a single input object, it is set up
+to process only a single input object.  A CL while loop may be written
+to process multiple objects, if desired.
+
+
+.ks
+.nf
+positional arguments:
+
+	image		filename
+	aperture	real
+	step_size	real
+	annulus		real
+	width_annulus	real
+	sky_mode	real
+.fi
+.ke
+
+
+.ks
+.nf
+hidden parameters:
+
+	fitsky		boolean		yes
+	center		boolean		yes
+	verbose		boolean		yes
+.fi
+.ke
+
+
+The radial profile is calculated from the image center out to the radius
+specified by the parameter APERTURE, in steps of STEP_SIZE pixels.
+The remaining RADPROF parameters are similar to those of APPHOT and will not be
+discussed in detail.  If background fitting is disabled, the parameter
+SKY_MODE defines the sky level.  The background fitting algorithm is
+a simple median calculation without pixel rejection or iteration.
+This should be sufficient, since RADPROF is expected to be used mainly
+in uncrowded regions on high signal to noise objects.
+Centering is via gaussian fits to the marginal profiles, without cleaning.
+
+RADPROF output lines contain the following fields:
+
+	r, i(r), inorm(r), fraction(r)
+
+.nf
+where
+
+	r		radius in pixels
+	i(r)		raw intensity at r
+	inorm(r)	normalized intensity at r (range 0-1)
+	fraction(r)	fraction of total integral at r
+.fi
+
+
+RADPROF does not generate any plots.  If one wishes to plot the contents
+of an output column, the column may be extracted with a list processing
+filter and piped to a graphics task.
+
+.sh
+4.0 Example
+
+    A brief example may help illustrate the use of the package.  Suppose
+we want to process a few hundred stars on images "blue" and "red".  We
+start by analyzing the blue image.
+
+	ap> radprof blue,15,0.5,20,10
+
+This gives us a radial profile printout for one of the "blue" stars.
+We decide that an aperture radius of 2.5 pixels is about right.
+The annulus will start at a radius of 10.0 pixels and extend to 20.0 pixels.
+The next step is to determine the FWHM of the PSF:
+
+	ap> fitpsf blue,3,10,20 | tee spoolfile
+
+By default, the program will take coordinate input by reading the image
+display cursor.  When the program is waiting for cursor input, it will
+cause the display cursor to blink rapidly; normally the cursor does not
+blink.  One has to be aware of this, because no other prompt is issued.
+We postion the cursor on several stars, and tap the space bar to measure
+each one.  When finished we type the EOF character (<ctrl/z> on our systems)
+to terminate the loop.  The screen will now look like this (the output 
+column labels are ommitted):
+
+.nf
+	ap> fitpsf blue,3,10,20 | tee spoolfile
+	 283.12  157.40 0.035  2.887  2.751
+	 546.08  213.45 0.023  2.833  2.902
+	 318.32  354.73 0.064  2.791  2.824
+.fi
+
+Since we elected to use TEE to spool the output, rather than the SPOOL
+parameter of FITPSF, we will not see the results until all stars have been
+measured.  The next step is to average the results, to determine the
+final FWHM (the FITPSF output could have been piped directly to GETCOLS
+without using an intermediate spoolfile, if desired).
+
+.nf
+	ap> getcols spoolfile,"4-5" | getcols | average
+	2.83133 0.0569725 6 
+.fi
+
+There are many ways this average could have been computed, of course;
+this is only one example.  Next, to avoid having to write down the FWHM value,
+we put it into the appropriate APPHOT parameter (note that the parameter
+name is abbreviated).
+
+	ap> apphot.fwhm = 2.831
+
+Finally, we must determine a representative backround sigma value for
+the image.  This is done by using FITSKY to measure several sky areas,
+and averaging column two of the output, much as we did for FITPSF.  The
+final value may be saved in "apphot.sky_sigma".
+
+By this point we have determined all the necessary parameters, and it is
+time to do some photometry.  The only APPHOT argument we are sure of is
+the image name parameter, so that is all we include on the command line:
+
+.nf
+	ap> apphot blue
+	aperture radii, pixels: 2.4 2.5 2.75 3.0
+	inner radius of sky annulus: 10
+	width of sky annulus (1 - ): 10
+	full width at half max of psf (2.831):
+	standard deviation of the image noise function (23.733):
+.fi
+
+After responding to the prompts shown above, APPHOT will ask for the
+first pair of object coordinates, and the cursor blink prompt will again
+be given.  Several objects may be measured to verify that all is working.
+
+The last step is to prepare a list of objects to be processed.  The simplest
+way to do this is to interactively mark the objects with the cursor.
+Later, when we process the "red" image, the same coordinate list may again
+be used, possibly after filtering with COORDTR.
+
+	ap> imcursor > objlist
+
+At this point, all of the APPHOT parameters have been set, we have
+a list of objects to be processed, and we are ready to run APPHOT in
+batch mode.  We decide to save the output in the file "blue.out".
+To ensure that we have a record of the parameters used for the fit,
+we first print the APPHOT parameters into the output file, then we
+start up the APPHOT batch run.
+
+.nf
+	ap> lparam apphot > blue.out
+	ap> apphot >> blue.out &
+	[1]
+.fi
+
+The batch job is now running, appending output lines to the file "blue.out".
+We can proceed to set up the job for the red image, in much the same way
+that we set up the job for the blue image.  When both jobs finish, we
+can use the list processing tools to filter out the good objects and
+calculate colors.
diff --git a/noao/digiphot/apphot/doc/specs/apphot.db b/noao/digiphot/apphot/doc/specs/apphot.db
new file mode 100644
index 00000000..df5dc2f3
--- /dev/null
+++ b/noao/digiphot/apphot/doc/specs/apphot.db
@@ -0,0 +1,366 @@
+# APPHOT.DDF -- Data definition for apphot package output
+
+builtin catalog functions
+builtin domain statements
+
+-------------------------------------------------------------------------------
+
+# domain statements
+
+domain	bool		type=short	format="%b"
+domain	posint		type=short	format="%5d"
+domain  pixels          type=real       format="%9.3f"
+domain	fwhmpsf		type=real	format="%9.3f"
+domain  counts		type=real	format="%15.7g"
+domain	sigma		type=real	format="%15.7g"
+domain  mag		type=real	format="%7.3f"
+domain  pars		type=real	format="%15.7g"
+domain  electrons	type=short	format="%5d"
+domain	ratio		type=real	format=%15.7g"
+
+# Apphot database descriptor
+record apphot {
+    iraf		char[]		"current version of iraf"
+    host		char[]		"host machine"
+    user		char[]		"user name"
+    package		char[]		"package name"
+    version		char[]		"package version"
+}
+
+--------------------------------------------------------------------------------
+
+# History record (1 per modification of the apphot database)
+record history {
+    task		char[]		"task name"
+    date		ltime		"date dask was run"
+    firstrec		posint		"first record written by task"
+    lastrec		posint		"last record written by task"
+}
+ 
+------------------------------------------------------------------------------ 
+
+# Data dependent parameter set (>= 1 per task execution)
+record datapars {
+    fwhmpsf		pixels		"full width half max of the psf"
+    emission		bool		"emission/absorption"
+    noise model		char[]		"data noise mode"
+    threshold		counts		"intensity threshold"
+    sigma		counts		"sigma of sky pixels"
+    gain		char[]		"image gain keyword"
+    epadu		ratio		"gain electrons/adu"
+    ccread		char[]		"image readout noise keyword"
+    readnoise		electrons	"readout noise electrons"
+}
+
+# Centering algorithm parameter set (>= 1 per task execution)
+record centerpars {
+    calgorithm		char[]		"centering algoritm"
+    cboxwidth		fwhmpsf		"centering box width"
+    maxshift		fwhmpsf		"maximum shift"
+    cmaxiter		posint		"maximum number of iterations"
+    minsnratio		ratio		"minimum signal to noise ratio"
+    clean		bool		"use clean algorithm"
+    rclean		fwhmpsf		"cleaning radius"
+    rclip		fwhmpsf		"clipping radius"
+    kclean		sigma		"sigma clean"
+}
+
+# Sky fitting algorithm parameter set (>= 1 per task execution)
+record fitskypars {
+    salgorithm		char[]		"sky fitting algorithm"
+    annulus		fwhmpsf		"inner sky annulus"
+    dannulus		fwhmpsf[]	"width of inner sky annulus"
+    smaxiter		posint		"maximum number od iterations"
+    skreject		sigma		"ksigma rejection"
+    snreject		posint		"maximum number of rejections"
+    khist		sigma		"half width of histogram"
+    binsize		sigma		"binsize of histogram"
+    smooth		bool		"smooth the histogram"
+    rgrow		fwhmpsf		"region growing radius"
+    skyvalue		counts		"user supplied sky value"
+}
+
+# Photometry parameter set (>= 1 per task execution)
+record photpars {
+    weighting		char[]		"weighting scheme"
+    apertures		fwhmpsf		"list of apertures"
+    zmagnitude		mag		"magnitude zero point"
+    exposure		char[]		"image exposure time keyword"
+    itime		""		"exposure time"
+}
+
+# Polygonal photometry parameter set (>= 1 per task execution)
+record polypars {
+    zmagnitude		mag		"magnitude zero point"
+    exposure		char[]		"image exposure time keyword"
+    itime		""		"exposure time"
+}
+
+# Radial profile fitting parameters (>= 1 per task execution)
+record radprofpars {
+    radius		fwhmpsf		"maximum profile radius"
+    stepsize		fwhmpsf		"profile step size"
+    order		posint		"number of spline pieces in fit"
+    kreject		sigma		"k sigma rejection"
+    nreject		posint		"max number of rejection cycles"
+}
+
+# Point spread function modeling parameters (>= 1 per task execution)
+record psfpars {
+    function		char[]		"analytic function"
+    box			fwhmpsf		"fitting box size"
+    kreject		sigma		"sigma rejection limit"
+    nreject		posint		"max number of rejections"
+}
+
+--------------------------------------------------------------------------------
+
+# Computed center answers (1 per star)
+record center {
+
+    datapars		posint		"record id of datapars record"
+    centerpars		posint		"record id of centerpars record"
+
+    image		char[]		"image name"
+    xinit		pixels		"initial x position"
+    yinit		pixels		"initial y position
+    id			posint		"sequence number in table"
+    coords		char[]		"coordinate list filename"
+    lid			posint		"sequence number in coord list"
+
+    xcenter		pixels		"x center position"
+    ycenter		pixels		"y center position"
+    xshift		pixels		"x position shift"
+    yshift		pixels		"y position shift"
+    xerror		pixels		"x position error"
+    yerror		pixels		"y position error"
+    cerrcode		posint		"centering error code"
+    cerrstring		char[]		"centering error message"
+
+}
+
+# Computed fitsky answers (1 per star)
+record fitsky {
+
+    datapars		posint		"record id of datapars record"
+    fitskypars		posint		"record id of fitskyprs record"
+
+    image		char[]		"image name"
+    xinit		pixels		"initial x position"
+    yinit		pixels		"initial y position
+    id			posint		"sequence number in table"
+    coords		char[]		"coordinate list filename"
+    lid			posint		"sequence number in coord list"
+
+    skyvalue		counts		"sky value"
+    skysigma		counts		"standard deviation of sky"
+    skyskew		counts		"skew of sky pixels"
+    nskypix		posint		"number of sky pixels"
+    nskyreject		posint		"number of rejected pixels"
+    serrcode		posint		"sky fitting error code"
+    serrstring		char[]		"sky fitting error message"
+
+}
+
+# Computed phot answers (1 per star)
+record phot {
+
+    datapars		posint		"record id of datapars record"
+    centerpars		posint		"record id of centerpars record"
+    photpars		posint		"record id of photometry record"
+
+    image		char[]		"image name"
+    xinit		pixels		"initial x position"
+    yinit		pixels		"initial y position
+    id			posint		"sequence number in table"
+    coords		char[]		"coordinate list filename"
+    lid			posint		"sequence number in coord list"
+
+    xcenter		pixels		"x center position"
+    ycenter		pixels		"y center position"
+    xshift		pixels		"x position shift"
+    yshift		pixels		"y position shift"
+    xerror		pixels		"x position error"
+    yerror		pixels		"y position error"
+    cerrcode		posint		"centering error code"
+    cerrstring		char[]		"centering error message"
+
+    skyvalue		counts		"sky value"
+    skysigma		counts		"standard deviation of sky"
+    skyskew		counts		"skew of sky pixels"
+    nskypix		posint		"number of sky pixels"
+    nskyreject		posint		"number of rejected pixels"
+    serrcode		posint		"sky fitting error code"
+    serrstring		char[]		"sky fitting error message"
+
+    aperts		pixels[]	"list of apertures"
+    sums		counts[]	"list of sums"
+    areas		pixels[]	"list of areas"
+    mags		mag[]		"list of magnitudes"
+    magerrs		mag[]		"list of mag errors
+    merrcodes		posint[]	"list of errcodes
+    merrstrings		char[]		"list of error messages"
+
+}
+
+# Computed wphot answers (1 per star)
+record wphot {
+
+    datapars		posint		"record id of datapars record"
+    centerpars		posint		"record id of centerpars record"
+    fitskypars		posint		"record id of fitskypars record"
+    photpars		posint		"record id of photpars record"
+
+    image		char[]		"image name"
+    xinit		pixels		"initial x position"
+    yinit		pixels		"initial y position
+    id			posint		"sequence number in table"
+    coords		char[]		"coordinate list filename"
+    lid			posint		"sequence number in coord list"
+
+    xcenter		pixels		"x center position"
+    ycenter		pixels		"y center position"
+    xshift		pixels		"x position shift"
+    yshift		pixels		"y position shift"
+    xerror		pixels		"x position error"
+    yerror		pixels		"y position error"
+    cerrcode		posint		"centering error code"
+    cerrstring		char[]		"centering error message"
+
+    skyvalue		counts		"sky value"
+    skysigma		counts		"standard deviation of sky"
+    skyskew		counts		"skew of sky pixels"
+    nskypix		posint		"number of sky pixels"
+    nskyreject		posint		"number of rejected pixels"
+    serrcode		posint		"sky fitting error code"
+    serrstring		char[]		"sky fitting error message"
+
+    aperts		pixels[]	"list of apertures"
+    sums		counts[]	"list of sums"
+    areas		pixels[]	"list of areas"
+    mags		mag[]		"list of magnitudes"
+    magerrs		mag[]		"list of mag errors
+    merrcode		posint[]	"list of errcodes
+    merrstrings		char[]		"list of error messages"
+}
+
+# Computed polyphot answers (1 per star)
+record polyphot {
+
+    datapars		posint		"record id of datapars record"
+    centerpars		posint		"record id of centerpars record"
+    fitskypars		posint		"record id of fitskypars record"
+    polypars		posint		"record id of polypars record"
+
+    image		char[]		"image name"
+    xinit		pixels		"initial x position"
+    yinit		pixels		"initial y position
+    id			posint		"sequence number in table"
+    coords		char[]		"coordinate list filename"
+    lid			posint		"sequence number in coord list"
+
+    xcenter		pixels		"x center position"
+    ycenter		pixels		"y center position"
+    xshift		pixels		"x position shift"
+    yshift		pixels		"y position shift"
+    xerror		pixels		"x position error"
+    yerror		pixels		"y position error"
+    cerrcode		posint		"centering error code"
+    cerrstring		char[]		"centering error message"
+
+    skyvalue		counts		"sky value"
+    skysigma		counts		"standard deviation of sky"
+    skyskew		counts		"skew of sky pixels"
+    nskypix		posint		"number of sky pixels"
+    nskyreject		posint		"number of rejected pixels"
+    serrcode		posint		"sky fitting error code"
+    serrstring		char[]		"sky fitting error message"
+
+    sum			counts[]	"aperture sum"
+    area		pixels[]	"aperture area"
+    mag			mag[]		"magnitude"
+    magerr		mag[]		"magnitude error"
+    merrcode		posint[]	"error code"
+    merrstring		char[]		"error message"
+
+    polygons		char[]		"name of polygons files"
+    pid			posint		"polygon sequence number"
+    oldxmean		pixels		"original mean x of polygon"
+    oldymean		pixels		"original mean y of polygon"
+    minradius		pixels		"min sky radius to exclude polygon"
+    nver		posint		"number of vertices"
+    xvertices		pixels[]	"list of x vertices coords"
+    yvertices		pixels[]	"list of y vertices coords"
+}
+
+# Computed radprof answers (1 per star)
+record radprof {
+
+    datapars		posint		"record id of datapars record"
+    centerpars		posint		"record id of centerpars record"
+    fitskypars		posint		"record id of fitskypars record"
+    photpars		posint		"record id of photpars record"
+    radprofpars		posint		"record id of radprofpars record"
+
+    image		char[]		"image name"
+    xinit		pixels		"initial x position"
+    yinit		pixels		"initial y position
+    id			posint		"sequence number in table"
+    coords		char[]		"coordinate list filename"
+    lid			posint		"sequence number in coord list"
+
+    xcenter		pixels		"x center position"
+    ycenter		pixels		"y center position"
+    xshift		pixels		"x position shift"
+    yshift		pixels		"y position shift"
+    xerror		pixels		"x position error"
+    yerror		pixels		"y position error"
+    cerrcode		posint		"centering error code"
+    cerrstring		char[]		"centering error message"
+
+    skyvalue		counts		"sky value"
+    skysigma		counts		"standard deviation of sky"
+    skyskew		counts		"skew of sky pixels"
+    nskypix		posint		"number of sky pixels"
+    nskyreject		posint		"number of rejected pixels"
+    serrcode		posint		"sky fitting error code"
+    serrstring		char[]		"sky fitting error message"
+
+    aperts		pixels[]	"list of apertures"
+    sums		counts[]	"list of sums"
+    areas		pixels[]	"list of areas"
+    mags		mag[]		"list of magnitudes"
+    magerrs		mag[]		"list of mag errors
+    merrs		posint[]	"list of error codes
+    merrstrings		char[]		"list of error messages"
+
+    pfwhm		pixels		"fitted profile fwhmpsf"
+    inorm		counts		"intensity normalization factor"
+    tinorm		counts		"total intensity normalization factor"
+    errcode		posint		"error code"
+    errstring		char[]		"error message"
+    rlist		pixels[]	"radii"
+    intensities		counts[]	"fitted intensities"
+    tintensities	counts[]	"integral of fitted total intensities"
+}
+
+# Computed fitpsf answers (1 per star)
+record fitpsf {
+
+    datapars		posint		"record id of datapars record"
+    fitpsfpars		posint		"record id of fitpsf record"
+
+    image		char[]		"image name"
+    xinit		pixels		"initial x position"
+    yinit		pixels		"initial y position
+    id			posint		"sequence number in table"
+    coords		char[]		"coordinate list filename"
+    lid			posint		"sequence number in coord list"
+
+    npars		posint		"number of parameters"
+    params		pars[]		"list of parameters"
+    parerrs		pars[]		"list of parameter errors"
+
+}
+
+-------------------------------------------------------------------------------
diff --git a/noao/digiphot/apphot/doc/specs/apphot.spc b/noao/digiphot/apphot/doc/specs/apphot.spc
new file mode 100644
index 00000000..ecfdf364
--- /dev/null
+++ b/noao/digiphot/apphot/doc/specs/apphot.spc
@@ -0,0 +1,1296 @@
+.EQ
+delim $$
+.EN
+
+.RP
+.TL
+Specifications for the Aperture Photometry Package
+.AU
+Lindsey Davis
+.AI
+.K2 "" "" "*"
+Revised October 1987
+
+.AB
+The APPHOT package is a set of tasks for performing aperture photometry
+on uncrowded or moderately crowded fields, in either interactive or batch mode.
+The photometric technique employed is fractional pixel aperture
+integration. Point spread function fitting techniques are not used and no
+knowledge of the point spread function is required for the computation of
+magnitudes. Separate tasks are provided for creating and modifying object lists,
+computing accurate centers for a list of objects, computing sky values for
+a list of objects and performing aperture photometry inside circular or
+polygonal apertures.
+.AE
+
+.NH
+Introduction
+.PP
+The APPHOT package is a set of tasks for performing
+aperture photometry on uncrowded or moderately crowded fields.
+The photometric technique employed is fractional pixel integration. Point
+spread function techniques are not used and no knowledge of the point spread
+function is required for the computation of magnitudes.
+.PP
+The APPHOT package performs multi-aperture photometry on digitized starfields
+maintained as IRAF image files. Input to the package consists of an
+image file, a list of object coordinates, numerous parameters controlling
+the analysis algorithms and, optionally, the graphics terminal and/or
+display. APPHOT output consists of successive lines of text where each line
+summarizes the results of the analysis for a particular object.
+.PP
+Given starting coordinates and an IRAF image, the principal APPHOT
+task computes accurate centers, sky values and magnitudes
+for a list of objects.  Separate
+IRAF callable tasks in APPHOT exist to create and modify object
+lists, to determine image characteristics such as the full width half maximum
+of the point spread function or standard deviation of the sky pixels,
+to compute accurate centers for a list of objects, to compute accurate local sky
+values for a list of objects, and to compute magnitudes inside a polygonal
+aperture.
+
+.NH
+APPHOT Package Requirements
+.NH 2
+APPHOT Package Input
+.NH 3
+The IRAF Image
+.PP
+APPHOT assumes that images exist on disk in IRAF format. Facilities for reading
+and writing images exist elsewhere in IRAF such as in package DATAIO or
+MTLOCAL.
+.PP
+APPHOT assumes that the image data is linear.
+The input image is assumed to have been corrected for those instrumental
+defects which affect the intensity of a pixel. These include pixel to
+pixel variations in the bias values, pixel to pixel gain variations,
+cosmic rays, cosmetic defects, geometric distortion,
+and detector non-linearities.
+.PP
+APPHOT assumes that the local sky background is approximately flat in the
+vicinity of the object being measured. This assumption is equivalent to
+assuming that the local sky region has a unique mode. Therefore any
+variations in the sky background which occur at the same scale as the
+sky region should be removed prior to entering APPHOT.
+.PP
+The point spread function of the image is assumed to be constant for all
+regions of the image. This is particularly critical in the case of faint objects
+for which small apertures which minimize the effects of crowding and
+sky noise in the aperture are used. The wings of the object will
+almost certainly extend beyond the aperture and good results will only be
+obtained if
+objects are consistently well centered and the shape and diameter of an object
+is constant throughout the image and invariant to magnitude.
+
+.NH 3
+The Coordinate Lists
+.PP
+All APPHOT tasks operate on lists of object coordinates or interactive cursor
+input.  Lists are maintained as text files,
+one object per line with the x and y coordinates in
+columns one and two respectively. List files may be created interactively
+with either the graphics or image cursor, by a previously executed APPHOT
+task, by a previously executed IRAF task or by a user task.
+.PP
+The x and y coordinates contained in the list file can be either the
+starting centers for the objects of interest or the true centers.
+In either case the aperture centered around the object position must
+not extend beyond the boundary of the image. To obtain reliable results
+from the centering algorithm the starting centers should not be more than
+1 fwhmpsf pixels from the true centers.
+
+.NH 3
+Algorithm Parameters
+.PP
+Many tasks in the APPHOT package have an associated set of algorithm parameters
+which control the operation of the analysis routines. For example the
+centering and sky fitting algorithms each have an associated group of
+parameters.
+The APPHOT tasks supply reasonable defaults for these parameters. However
+the user may alter them at any time in interactive mode or by editing the
+appropriate parameter file before running the task in batch. 
+
+.NH 3
+Terminal Graphics and the Image Display
+.PP
+Most APPHOT programs may be run in either interactive or batch mode.
+In interactive mode, the user can mark the positions of objects by
+interactively, positioning the image cursor on the display device.
+Simple cursor commands can interactively alter the algorithm parameters. 
+In batch mode the algorithm parameters are
+fixed and object coordinates are taken from the user supplied coordinate list.
+The display device is not required in batch mode.
+.PP
+At present there is no high level IRAF display interface. Therefore the present
+version of APPHOT replaces the display device with terminal
+graphics. For example it is possible to load a contour plot of an image
+or image section, and run the APPHOT tasks, interactively marking
+positions on the plot. This is a temporary measure to tide thing over until
+the display interface is available. Furthermore this option is only
+really suitable for those terminal which have both text and graphics
+windows displayed at the same time.
+.PP
+Certain APPHOT tasks such as FITSKY occasionally require an interactive graphics
+capability. For example it is sometimes desirable to plot the histogram
+of the sky pixels and mark the peak of the histogram interactively rather
+than using the automatic sky fitting routines.
+Graphics capablity has been added to APPHOT tasks as deemed useful.
+
+.NH 2
+APPHOT Package Functions
+.NH 3
+Creating Coordinate Lists
+.PP
+APPHOT task(s) shall exist to create coordinate lists interactively within
+APPHOT by loading the IRAF image into the image display
+and successively marking the objects to be measured with the image cursor.
+It shall be possible to mark the positions of objects on the display, and draw
+circles of arbitrary size around the objects of interest.
+It shall be possible to verify existing coordinate lists by marking the object
+coordinates on the image display.
+.PP
+At present the full image display cababilities do not exist in IRAF.
+Therefore as a temporary measure most tasks will run with a contour
+plot and the graphics cursor as a substitute for the image display and
+image cursor by setting the image cursor to stdgraph and the display
+parameter for each task to stdgraph.
+The output coordinates will be written to a text file and may be used as
+starting coordinates for the APPHOT routines.
+.PP
+Those sites which have SUN workstations can use the IMTOOL facilites to
+create cursor lists.
+.PP
+APPHOT tasks shall exist to automatically detect objects by specifying the IRAF
+image to be searched, plus a few image characteristics such as a detection 
+threshold and the full width half maximum of the point spread function.
+The output coordinates plus a few object statistics  will be written to a
+text file.
+
+.NH 3
+Coordinate List Operations
+.PP
+General list processing tasks are or will be available in the IRAF lists
+package. Examples of useful currently existing tasks are list sorting by for
+example magnitude and performing a linear transformations
+on coordinate lists.
+.PP
+It may eventually be necessary to add some specialized list processing tasks
+to APPHOT. One example is a list matching facility in which objects in
+common to two lists are combined and output to a third list.
+
+.NH 3
+Determining the Image Characteristics
+.PP
+APPHOT tasks shall exist to estimate certain image
+characteristics such as the full width half maximum of the image point spread
+function and the standard deviation of the background. In order to obtain
+meaningful error estimates it is also necessary to specify the noise
+charactersitics of the detector and a noise model.
+In this version of APPHOT two noise
+functions will be supported a constant sky background noise,
+and constant background noise plus Poisson statistics in the object.
+.PP
+The reason for this capability is that the majority of the APPHOT
+algorithm parameters scale with these two image characteristics.
+For example all the pixel scale dependent parameters such as the centering
+aperture, object apertures, the two sky annuli and the
+maximum shift parameter all scale with the full width half
+maximum of the point spread function. Similarly most of the pixel intensity
+dependent parameters scale with the standard deviation of the sky pixels.
+
+.NH 3
+Centering
+.PP
+An APPHOT task shall exist to determine accurate centers for a list of objects,
+using the approximate object coordinates as a starting point.
+The centering aperture may extend beyond the boundaries of the image but
+a warning message will be generated.
+.PP
+A choice of centering algorithms with a range of efficiency and accuracy will
+be available.  The center determination must be resistant to the affects of
+nearby contaminating objects.
+.PP
+The user may opt to use the starting center as the actual center in all cases,
+to use the starting center as the actual center if the object is very faint,
+or tweak up the center if the signal to noise is above a certain threshold.
+.PP
+The output of the centering algorithm will the set of computed coordinates
+and their errors.
+
+.NH 3
+Fitting the Sky
+.PP
+An APPHOT task shall exist to compute a constant background value by analysis
+of an annular region surrounding the object.
+The background is assumed to be flat in the region
+of the object, but may contain contaminating objects or defects which
+shall be detected and eliminated by the fitting algorithm.
+It shall be permissible for the background region to extend beyond the
+boundaries of the image; the out of bounds region of the background shall
+be excluded from the fit.
+.PP
+The user may supply a constant background, with zero-valued noise and skew
+value or read appropriate values from a file instead of computing the
+background.
+.PP
+The output of the sky fitting algorithm shall be
+the mode, standard deviation and skew of the sky as well as the number
+of pixels left in the background region after pixel rejection and the number
+rejected.
+
+.NH 3
+Multi-aperture Photometry
+.PP
+APPHOT routines shall exist to compute the integral of object minus background
+within one or more circular apertures centered upon the object.
+The integration shall be
+performed using partial pixel techniques, to minimize the effects of
+sampling.  If the aperture contains any indefinite pixels, or if the
+aperture extends beyond the boundary of the image, an indefinite result
+shall be returned. Both normal and weighted photometry routines shall
+be available.
+.PP
+It shall be possible to normalize the output magnitudes to a user specified
+integration time using values stored in the IRAF image header.
+.PP
+The output shall consist of magnitudes and errors for each of the specified
+apertures.
+.NH 3
+Polygonal Aperture Photometry
+.PP
+Determine the integral of the object within a specified
+polygon. Aperture integration shall be by fractional pixel summation
+of successive image lines.
+
+.NH
+Specifications
+.NH 2
+Apphot CL Callable Tasks
+.PP
+The CL callable part of the APPHOT package consists of the following
+routines:\fL
+
+.nf
+.na
+        mark    -- create/verify coordinate lists interactively
+    polymark    -- create/verify polygon lists interactively
+     daofind    -- automatic image finder from DAOPHOT
+     lintran    -- linearly transform a list of coordinates (LISTS package)
+
+     radprof    -- compute the radial profile of an object.
+      fitpsf    -- model the PSF
+
+      center    -- compute accurate centers for a list of objects
+      fitsky    -- compute accurate sky values for a list of objects
+        phot    -- perform multi-aperture photometry on a set of objects
+    polyphot    -- compute the flux inside a set of irregular polygons\fR
+       wphot	-- perform weighted multi-aperture photometry
+.ad
+.fi
+
+.NH 2
+Standard Analysis Procedures
+.PP
+A standard reduction procedure would be something as follows.
+.IP 1.
+Estimate the image and data characteristics in the following manner.
+.RS
+.IP 1.
+Use the interactive setup option (i key) in the PHOT task to specify the
+fwhm of the psf,
+the centering apperture, the sky annuli, the photometry apertures as
+well as estimate the sky sigma.
+Examine the results (:show command) and optionally store the 
+new parameters in the parameter files (w key).
+.IP 2.
+Use the EPAR task to edit the parameter files directly. For example the
+detector gain and readout noise must be known before running PHOT in
+order to get reliable error estimates.
+.RE
+.IP 2.
+Prepare a coodinate list in one of the following ways.
+.RS
+.IP 1.
+Running MARK or POLYMARK.
+.IP 2.
+Run DAOFIND or some other automatic image finder.
+.IP 3.
+Run another APPHOT task such as CENTER .
+.IP 4.
+Run any other IRAF or user program which generates the appropriate
+format.
+.IP 5.
+Transform an existing list using the LISTS package facilities
+.RE
+.IP 3.
+Run PHOT or WHOT in non-interactive mode to perform the multi-aperture
+photometry.  The user should be familiar
+with the algorithms used to measure the object center, to fit the background,
+and compute the aperture integral, magnitude, and errors.  The values of
+all visible and hidden PHOT parameters should be inspected before doing
+any serious processing. Note that CENTER and FITSKY can be run independently
+of PHOT and their output used as input to PHOT.
+.EQ
+delim $$
+.EN
+
+.NH 2
+The APPHOT Algorithms
+.PP
+The principal APPHOT algorithms are described below.
+
+.NH 3
+The RADPROF Algorithm
+.PP
+The function of the RADPROF task is to compute the radial profile of
+selected, isolated, high signal to noise objects in an IRAF image.
+.PP
+Given the IRAF image, an initial center, an aperture and a step size,
+RADPROF computes the radial profile of an object in the following manner.
+.IP 1.
+The APPHOT centering routines are used to compute an accurate center for the
+object. The new center is used to compute the radial coordinate for each
+pixel in the subraster.
+.IP 2.
+The APPHOT sky fitting routines are used to compute an accurate sky value
+for the object. The new sky value is used to compute the object intensity
+for each pixel in the subraster.
+.IP 3.
+The CURFIT package routines are used to produce a smooth intensity versus
+radius curve by fitting a cubic least squares spline function to the data
+using linear least squares techniques.
+.IP 4.
+The fitted curve is evaluated at equally spaced intervals to produce the
+final radial profile. The profile is normalised using the r = 0 value.  
+.IP 5.
+The smoothed curve is integrated using the 
+1D integration routines IMINTERP to evalute the fraction of the total
+integral at each interval.
+.IP 6.
+The three quantities $I sub r$ the raw intensity, $Inorm sub r$ the
+normalized intensity, and $Ifraction sub r$ the fraction of the total
+intensity inside radius at r,  are plotted on the terminal and
+output as a function of r to a text file.
+.PP
+RADPROF is used principally to compute the stellar image and setup the
+parameters for doing photometry. Its default output is a radial profile
+plot with the phot parameters marked on it.
+
+.NH 3
+The FITPSF Algorithm
+.PP
+The function of the FITPSF task is to fit an analytic model to an object
+in order to derive information about the point spread function. Given
+an IRAF image, an initial center and an aperture, FITPSF computes the
+model parameters in the following manner.
+.IP 1.
+The fitting function is chosen.
+The present version of FITPSF offers two function choices a 2D radial Gaussian
+function and an elliptical Gaussian function.
+A third option, moment analysis, has been added to the FITPSF package.
+The image characteristics are evaluted by using the 0th, 1st and 2nd order
+moments of the image.
+.IP 2
+Initial guesses for the parameters are made from the subraster data.
+.IP 3
+The parameters and their errors are derived using standard non-linear least
+squares techniques and the NLFIT package.
+
+.NH 3
+The DAOFIND Algorithm
+.PP
+The function of the DAOFIND task is to automatically detect objects
+in an IRAF image above a certain intensity threshold.
+The user specifies an intensiyt threshold,
+the estimated full width half maximum of
+the point spread function,
+and limits on the sharpness and roundness of the objects to be detected.
+DAOFIND produces a list of x and y coordinates and a sharpness
+and roundness statistic for each detected object.
+.PP
+The DAOFIND algorithm works in the following way.
+.IP 1.
+The user specifies an intensity threshold above local sky and estimates
+the full width half maximum of the point spread function.
+.IP 2.
+DAOFIND computes a convolution kernel which is a linear
+function of the brightness values in an approximately circular array of
+pixels.  The original data is convolved with the computed kernel.
+The equivalent mathematical
+operation is a convolution of the original data
+with truncated, lowered circular Gaussian function with the specified FWHM,
+computed in such a way as to be the mathematical
+equivalent of fitting a Gaussian stellar profile to the object data by least
+squares. The coefficients of the linear function sum to zero so that the
+overall bias level (local sky) cancels out exactly. Since the function is
+symmetric about a single pixel, a smooth gradient in the sky brightness
+also cancels exactly. Therefore the user does not have to specify an
+absolute brightness threshold but only a threshold above local sky.
+.IP 3
+The convolved data is searched for local maxima. Local maxima which are
+less than the specified threshold are rejected. A pixel is defined to be
+a local maximum when it is the brightest pixel within
+$n ~*~ sigma sub Gauss$.
+.IP 4.
+Using the original data, DAOFIND computes an object sharpness statistic which
+can be used to reject
+hot or cold pixels.  The sharp parameter is defined below.
+Detected  objects with a sharpness parameter outside the range specifed
+by sharplo and sharphi are rejected. Typical values for sharplo and
+sharphi are 0.2 and 1.0 respectively.
+.nf
+
+    $I sub delta$ = height of best fitting $delta$ function = pixel value
+
+    $I sub Gauss$ = height of best fitting Gaussian function = convolved value
+
+    sharplo <= sharp = ${I sub delta} over {I sub Gauss}$ <= sharphi
+
+.fi
+If the brightness enhancement detected in the convolved data is due to
+a single bright pixel, then the best fitting delta function will have an
+amplitude equal to the height of this pixel above the local background,
+while the amplitude of the best fitting Gaussian will be pulled down by
+the surrounding low valued pixels. Sharp will be a number significantly
+greater than one. A single cold pixel will produce
+brightness enhancements approximately 0.5 * FWHM away
+from the pixel in question  in all directions. In this case the height
+of the delta
+function which best fits these spurious maxima is close to zero, while the
+height of the best fitting Gaussian is some small positive number.
+In this case sharp will be close to zero.
+.IP 5.
+The roundess statistic is computed from the original picture data by fitting
+1D Gaussians
+to the marginal sums in x and y. If the height of either 1D
+Gaussian is negative the object is rejected. If both heights are
+positive the roundness parameter is computed.
+.nf
+
+	$DELTA I ~=~ I sub {x ~ Gauss} ~-~ I sub {y ~ Gauss}$
+
+	$<I> ~=~ I sub {x ~ Gauss} ~+~ I sub {y ~ Gauss}$
+
+	$roundlo ~<=~  round ~=~ {DELTA I} over <I> ~<=~  roundhi$
+
+.fi
+Objects which are elongated in the
+x direction have roundness values less than zero and those elongated in
+the y direction have roundness greater than zero.
+Round discriminates only against objects which are elongated
+along either rows or columns. Objects elongated at a 45 degree angle will
+not be rejected.
+.IP 6.
+Finally the approximate x and y centroids of the detected objects,
+rough magnitudes relative to threshold are computed, and object is added
+to the output file.
+
+
+.NH 3
+The CENTER Task
+
+.NH 4
+Centering Package Routines
+.PP
+The following are the principal programmer callable routines routines in the
+centering package.
+.nf
+\fL
+
+                  apcinit (ap, cfunction, cbox, fwhmpsf, noise)
+            ier = apfitcenter (ap, im, xinit, yinit)
+            ier = aprefitcenter (ap)
+          value = apstat[ir] (ap, param)
+                  apstats (ap, param, str, maxch)
+                  apset[sir] (ap, param, value)
+                  apcfree (ap)
+
+\fR
+.fi
+.PP
+The following quantities can be examined or set by apstat/apset calls
+.nf
+\fL
+  data          1. fwhmpsf       full width half maximum of psf in pixels
+parameters      2. threshold     minimum intensity for centering
+                3. noise         noise model
+                4. sigma         standard deviation of background
+                5. readnoise     readout noise of CCD in electrons
+                6. epadu         electrons per adu
+
+centering       1. calgorithm    centering algorithm
+parameters      2. positive      emission / absorption features
+                3. cbox          centering radius in fwhmpsf
+                4. cmaxiter      maximum number of fitting iterations
+                5. maxshift      maximum permitted shift in fwhmpsf
+                6. minsnratio    minimum permitted signal to noise ratio
+                7. clean         clean subraster before centering
+                8. rclean        cleaning radius in fwhmpsf
+                9. rclip         clipping radius in fwhmpsf
+                10.kclean        k-sigma rejection for cleaning in sigma
+\fR
+.fi
+
+.PP
+The following computed quantities can be examined by apstat calls.
+.nf
+\fL
+              1. xcenter            computed x coordinate
+              2. ycenter            computed y coordinate
+              3. xerr               computed x coordinate error
+              4. yerr               computed y coordinate error
+\fR
+.fi
+.PP
+See the manual pages for CENTER and CENTERPARS for a detailed description
+of the centering parameters.
+
+.NH 4
+The Centering Algorithm
+.PP
+The function of the CENTER task is to compute accurate centers and errors
+for objects in an IRAF image given a list of initial positions and a
+centering aperture.
+.IP 1.
+If the centering algorithm is disabled, the computed center is set to the
+initial center and the uncertainty estimate is set to zero.
+.IP 2.
+If the cleaning algorithm is enabled, clean the subraster before centering.
+.IP 3.
+Estimate is made of the signal to noise of the object. If this quantity is
+less than a certain minimum value the computed center is kept
+but a warning message is issued.
+.IP 4.
+The center and errors are computed using one of several algorithms.
+.IP 5.
+If the computed center is greater than a user specified distance from the
+initial center then the computed center is returned with an error
+message.
+
+.NH 4
+Symmetry Clean Algorithm
+.PP
+The symmetry-clean algorithm attempts to remove defects in the centering
+subraster by assuming that the object has radial symmetry and comparing
+pixels on the opposite sides of the center of symmetry. The algorithm
+works in the following way.
+.IP 1.
+The center of symmetry is computed. Normally the center of symmetry is assumed
+to coincide with the position of the brightest pixel in the subarray.
+However if the maximum pixel is more than a user specified distance away
+from the intial center, the initial center is used as the center of symmetry.
+.IP 2.
+Pixels inside a specified cleaning radius are unaltered.
+.IP 3.
+Pairs of pixels diametrically opposed about the center
+in the cleaning region between the cleaning and clipping
+radii are tested for equality.  If the difference between the pixels is
+greater than a specified k-sigma rejection limit, the larger value is replaced
+by the smaller.
+In this region sigma is computed from Poisson statistics.
+.IP 4.
+Pairs of pixels in the clippping
+region are compared in the same manner as those in the cleaning region
+except that sigma is the standard deviation of the sky pixels.
+.PP
+The effect of the symmetry-clean algorithm is to edit the raster,
+removing any contaminating objects in the vicinity of the primary object.
+This simplifies the fitting algorithm and increases its reliability,
+since it does not have to deal with multipeak marginal distributions.
+
+.NH 4
+Signal to Noise Estimate
+
+.PP
+The signal to noise of the object is estimated from the data values
+in the subraster in the following way.
+.nf
+
+	$SNR ~=~ N sub object over {sqrt {n sub pix ~*~sigma sub sky sup 2}}$
+
+		or
+
+	$SNR ~=~ N sub object over {sqrt {N sub object ~+~ n sub pix~*~sigma sub sky sup 2}}$
+
+.fi
+where $N sub *$ is the number of counts in the object above threshold,
+$sigma sub sky$
+is the standard deviation of the pixels in the sky region and
+$n sub pix$ is the number of pixels in the object aperture.
+The first approximation corresponds to constant sky noise only,
+the second includes Poisson noise in the object.
+
+.NH 4
+Centroid
+.PP
+The centroid centering algorithm is similar to that used in MPC and can
+be briefly described as follows. For more detailed description
+see (Stellar Magnitudes From Digital Pictures, 1980, Adams et al).
+.IP 1.
+The marginal distributions in x and y are accumulated.
+.IP 2.
+The intensity weighted centroid positions for the marginals is computed
+using only data pixels which are above the threshold intensity. If the
+threshold parameter is 0 the mean intensity of the marginal is used
+in place of the threshold
+.nf
+
+    $I sub i ~=~ I sub i ~-~ threshold ~~~~~ I sub i ~>~ 0.0$
+
+    $x sub c ~=~ {sum I sub i ~ x sub i} over {sum I sub i}$
+
+.fi
+.IP 3.
+The errors are estimated in the following way
+.nf
+
+    $sigma sup 2 ~=~ {sum I sub i ~ x sub i sup 2} over {sum I sub i} ~-~ x sub c sup 2$
+
+    $err sub xc ~=~ sqrt {{sigma sup 2} ~/~ sum I sub i}$
+
+.fi
+
+.NH 4
+Gaussian Fit to the Marginals
+.PP
+The fit is performed in the following way.
+.IP 1.
+The  marginal distributions in x and y are accumulated.
+.IP 2.
+Initial guesses for the parameters of the 1D Gaussians $I sub Gauss$,
+$x sub c$ and $I sub sky$ are derived from the marginal distributions
+themselves. The width $sigma$ is held constant.
+.IP 3.
+The best fit parameters and their errors are derived using non-linear
+least-squares techniques and the NLFIT package.
+
+.NH 4
+Optimal Filtering of Marginals
+.PP
+The fit is performed is the following way.
+.IP 1.
+The marginal distributions in x and y are accumulated.
+.IP 2.
+The centroid of the observed distribution is computed by solving the
+following equation.
+.nf
+
+        $PSI (x sub c ) ~=~ sum omega sub i (x sub c ) ~ PHI sub i ~=~ 0$
+
+        $omega sub i ~=~ {{partial phi sub i} ~/~ {partial x sub c}} over {phi sub i~+~b}$
+
+.fi
+The assumptions are that the observed distribution $PHI sub i$ is correctly
+modeled by the profile function $phi sub i$. The usual choise of profile
+model for centering is a Gaussian. Howver in the interests of speed a triangle
+function has been substituted. This causes at most a 7% increase in the
+random centering error.
+.IP 3.
+The startup procedure is based on the following fact.
+.nf
+
+	$PSI (x sub n )~>~0~~for~~ x sub n ~<~ x sub c$
+
+	$PSI (x sub n ) ~<~0~~for~~ x sub n ~>~ x sub c$
+
+.fi
+The iteration is initialized by assuming that $x sub 1$ = $x sub c$ and
+computing $PSI (x sub 1 )$. The initial x 
+value is incremented by $+- sigma sub Gauss$ depending on the sign of $PSI$. The
+search is repeated until $PSI (x sub {n-1})$ and $PSI (x sub n)$ have
+opposite signs. At this point the true center is bracketed by the
+estimated positions $(x sub n, ~ x sub {n-1})$ and we have a table of at
+least 2 values of $PSI (x sub n )$.
+.IP 4.
+The computation proceeds by interpolating in the table of values for the
+estimated position $x sub {n+1}$ where $PSI$ = 0. If the table contains only
+two values as may be the case for the inititial interpolation, linear
+interpolation is used. In all other cases a quadratic fit to the three
+most recent $PSI$ values is used. The computation is complete when
+two successive estimates differ by less than some tolerance typically
+0.001 pixel.
+.IP 5.
+The errors are estimated as follows.
+.nf
+
+    $sigma sup 2 ~=~ ( {int {( partial phi ~/~ partial x sub c )} sup 2 over {
+    phi + b}} ) sup -1$
+
+    $err sub xc ~=~ sqrt {sigma sup 2}$
+
+.fi
+
+.NH 4
+Other Centering Methods
+.PP
+The code is constructed in such a way that new algorithms may be
+easily added at a future date, such as the more sophisticated techniques
+required for accurate astrometry.
+.EQ
+delim $$
+.EN
+.NH 3
+The FITSKY Task
+
+.NH 4
+Sky Fitting Routines
+
+.PP
+The following are the main entry points in the sky fitting package.
+.nf
+\fL
+         apsinit (ap, function, annulus, dannulus, fwhmpsf, noise)
+   ier = apfitsky (ap, im, xpos, ypos, sd, gd)
+   ier = aprefitsky (ap, sd, gd)
+ value = apstat[ir] (ap, param)
+	 apstats (ap, param, str, maxch)
+         apset[irs] (ap, param, value)
+         apsfree (ap)
+\fR
+.fi
+.PP
+The following quantities can be examined or set with apset/apstat calls.
+.nf
+\fL
+data             1. fwhmpsf     full width half maximum of the psf
+parameters       2. sigma       standard deviation of sky pixels
+
+sky fitting      1. annulus     inner radius of sky annulus in fwhmpsf
+parameters       2. dannulus    outer radius of sky annulus in fwhmpsf
+                 3. sfunction   sky fitting algorithm
+                 4. smaxiter    maximum number of fitting iterations
+                 5. kreject     k-sigma rejection limit sigma
+                 6. nreject     maximum number of rejection cycles
+                 7. rgrow       region growing radius in fwhmpsf
+
+                 8. khist       half-wdth of histogram in sigma
+                 9. binsize     binsize of histogram in sigma
+                 10.smooth      Lucy smooth the histogram
+
+                 11.skyfile     name of text file containing sky values
+                 12.skyvaluser  supplied constant value for sky
+\fR
+.fi
+.PP
+The following computed quantities can only be examined with apstat calls.
+.nf
+\fL
+              1. skymode           computed sky value
+              2. skysig            computed sky sigma
+              3. skyskew           computed sky skew
+              4. nsky              number of sky pixels
+              5. nsky_reject       number of rejected sky pixels   
+\fR
+.fi
+
+.NH 4
+The Sky Fitting Algorithms
+.PP
+A good background fit is essential to aperture photometry.  Fitting
+the background is trivial in a sparse field, but difficult in a crowded
+field.  In general the background region will contain contaminating objects
+which must be detected and excluded if a good fit is to be obtained.
+.PP
+The main algorithm used in APPHOT is the following.
+.IP 1.
+If the skyfitting switch is disabled either read the sky values from a text
+file or accept a user supplied constant for the sky.
+.IP 2.
+Perform the initial sky fit using one of the specified algorithms. The
+sky fitting algorithms fall into three general categories, those that use
+the actual sky pixel array itself, those that operate on a histogram of
+sky values and those that rely on user interaction.
+.IP 3.
+If the pixel rejection flags are set perform pixels rejection with optional
+region growing.
+
+.NH 4
+Sky Pixel Array Techniques
+
+.NH 5
+Median
+.IP 1.
+Sort the array of sky pixels. This is necessary to avoid quantization effects.
+.IP 2.
+Compute the median, and the standard deviation and skew with respect to the
+mean.
+.IP 3.
+If the k-sigma rejection limit is greater than zero and the maximum number
+of rejection cycles is greater than one, perform pixel rejection.
+Pixels greater than k-sigma from the median are rejected. Region growing
+is optional.
+.IP 4.
+Stop the rejection cycle on any given iteration if the maximum number of
+rejection cycles ix exceeded, no more sky pixels are left or no more
+pixels are rejected.
+
+.NH 5
+Mode
+.IP 1.
+Sort the array of sky pixels. This is necessary to avoid quantization effects.
+.IP 2.
+Compute the mode, and the standard deviation and skew
+with respect to the mean.
+.nf
+
+	$I sub mode ~=~ 3.0 ~*~ I sub median ~-~ 2.0 ~*~ I sub mean$
+
+.fi
+.IP 3.
+If the k-sigma rejection limit is greater than zero and the maximum number
+of rejection cycles is greater than one, perform pixel rejection.
+Pixels greater than k-sigma from the mode are rejected. Region growing
+is optional.
+.IP 4.
+Stop the rejection cycle on any given iteration if the maximum number of
+rejection cycles ix exceeded, no more sky pixels are left or no more
+pixels are rejected.
+
+
+.NH 4
+Histogram Techniques
+.PP
+The following three techniques all operate on the histogram of the sky pixels.
+The routines all construct the histogram in the following identical manner.
+.IP 1.
+The mean of the sky distribution is computed.
+.IP 2.
+If the user specified standard deviation of the sky pixels is INDEF the
+algorithm computes the standard deviation of the sky pixels with respect
+to the mean.
+.IP 3.
+All pixels within plus or minus sigma standard
+deviations are accumulated into a histogram. The user specifies the bin size.
+.IP 4.
+The histogram may optionally be Lucy smoothed before any operation is performed
+on it.
+
+.NH 5
+Centroid
+.PP
+The mode, sigma and skew of the sky pixels are computed in the following
+manner.
+.IP 1.
+The histogram is compiled as above.
+.IP 2.
+The mode, standard deviation and skew of the sky pixels are computed in the
+following manner.
+
+.nf
+    $I sub 0 ~=~ sum I sub i$
+    $I sub 1 ~=~ sum I sub i ~ x sub i$
+    $I sub 2 ~=~ sum I sub i ~ x sub i sup 2$
+    $I sub 3 ~=~ sum I sub i ~ x sub i sup 3$
+
+    $I sub mode ~=~ {I sub 1} ~/~ {I sub 0}$ 
+    $sigma ~=~ {( I sub 2 ~/~ I sub 0 ~-~ I sub mode sup 2 )} sup {1/2}$
+    $skew ~=~ ( {I sub 3 ~/~ I sub 0 ~-~ I sub mode ~*~ sigma sup 2 ~-~ I sub mode sup 3} ) sup {1/3}$
+
+.fi
+.IP 3
+If pixel rejection is enabled sky pixels within a user supplied limit of
+the mode are rejected with optional region growing.
+
+.NH 5
+Gaussian Fit
+.PP
+The mode, standard deviation and skew of the sky pixels are derived from a
+model fit in the following way.
+.IP 1.
+The histogram of the sky pixels is compiled as above. 
+.IP 2.
+Initial guesses to the model parameters, $N sub max$, $I sub mode$,
+$sigma$, and $skew$ are made from the histogram itself.
+.IP 3.
+Final parameters and their errors are derived using non-linear least squares
+techniques and the NLFIT package.
+.IP 4.
+If pixel rejection is enabled sky pixels within a user supplied limit of
+the computed mode are rejected with optional region growing.
+
+.NH 5
+Optimal Filtering
+.PP
+The method is as follows.
+.IP 1.
+The histogram is compiled as above.
+.IP 2.
+Using the mean of the sky pixels as the intital value of the sky mode,
+a new mode is computed using the optimal filtering technique
+described for centering.
+.IP 4
+If pixel rejection is enabled sky pixels within a user supplied limit of
+the computed mode are rejected with optional region growing.
+
+.NH 5
+Cross Correlation
+.PP
+The method is as follows.
+.IP 1.
+The histogram is compiled as above.
+.IP 2.
+The noise function is estimated using the standard deviation of the sky
+pixels and the cross-correlation function is computed.
+.IP 3.
+The mode is computed using quadratic interpolation around the peak of the
+distribution.
+.IP 4
+If pixel rejection is enabled sky pixels within a user supplied limit of
+the mode are rejected with optional region growing.
+
+.NH 4
+Interactive Techniques
+
+.NH 5
+Histogram Plot
+.PP
+The histogram is compiled as described above and the user marks the peak
+on the histogram plot with the graphics cursor. The sigma and skew of the
+sky distribution with respect to the mean is also computed.
+
+.NH 5
+Radial Distribution
+.PP
+A radial profile plot of the sky region is plotted and the user marks the
+sky value on the plot with the graphics cursor. The sigma and skew of the sky
+distribution with respect to the mean is computed.
+
+.NH 4
+Pixel Rejection and Region Growing
+.PP
+All the sky fitting algorithms permit pixel rejection and
+optional region growing.
+Pixel rejection  and region growing are
+performed by locating all pixels more than k * sigma from the mode,
+and blindly rejecting all pixels within a certain radius of each deviant
+pixel.  This simple algorithm works well because the sample is large,
+and therefore there is little penalty for discarding pixels that might
+not be deviant.  Region growing also tends to accelerate convergence
+significantly.
+.PP
+Very faint contaminating objects are difficult to detect and reject.
+If there are enough such objects, they should not be rejected, because
+there are probably a few in the object aperture as well.  A higher sky
+sigma will be calculated and the computed uncertainty in the magnitude
+will increase.  The best solution to this problem may be to increase
+the size of the annulus to minimize the bias.
+
+.NH 4
+The Principal PHOT Routines
+.PP
+The main entries in the photometry routine are the following.
+.nf
+\fL
+               apinit (ap, cfunction, cbox, sfunction, annulus, dannulus,
+                aperts, napert, fwhmpsf, noise)
+         ier = apfitcenter (ap, im, xinit, yinit)
+         ier = aprefitcenter (ap)
+         ier = apfitsky (ap, im, xcenter, ycenter, sd, gd)
+         ier = aprefitsky (ap, sd, gd)
+         ier = apmag (ap, im, xcenter, ycenter, skyval, skysig, nsky)
+         ier = apwmag (ap, im, xcenter, ycenter, positive, skyval, skysig, nsky)
+         ier = apremag (ap, positive, skyval, skysig, nsky)
+         ier = apwremag (ap, positive, skyval, skysig, nsky)
+       value = apstat[ir] (ap, param)
+               apstats (ap, param, str, maxch)
+               apset[sir] (ap, param, value)
+               apfree (ap)
+
+\fR
+.fi
+.PP
+The following parameters can be examined or altered by apset/apstat calls.
+.nf
+\fL
+                1. weighting        weighting scheme for wphot
+                2. aperts           list of apertues
+                3. naperts          number of apertures
+                4. zmag             zero point of magnitude scale
+                5. itime            effective integration time
+\fR
+.fi
+.PP
+The following quantities can be examined with apstat calls.
+.nf
+\fL
+
+                1. sums            array of aperture sums
+                2. areas            array of areas
+                3. mags             array of magnitudes
+                4. magerrs          array of magnitude errors
+
+\fR
+.fi
+
+.NH 4
+The PHOT Aperture Integration Algorithm
+.PP
+The integral of the flux within a circular aperture is computed by
+fractional pixel techniques.  Pixels are assumed to be square apertures
+arranged in a rectangular grid.  The fraction of a pixel which lies within
+the circular APPHOT aperture is computed by an approximation, and all
+such contributions are summed to produce the total integral.
+.PP
+The inclusion of a partial pixel inside the aperture is done as follows.
+.IP 1.
+If the distance of the current pixel from the center of the star, r, is
+exactly equal to the radius of the aperture R then one-half the counts in
+the pixel are included.
+.IP 2.
+If r < R - 0.5 the entire pixel is included while if r > R + 0.5 the pixel
+is wholly excluded.
+.IP 3.
+In between the fraction of the counts varies linearly. A circular aperture
+is approximated by an irregular polygon.
+.PP
+The simplicity of aperture photometry limits the amount of information
+available for error analysis.  The following three sources of error are
+considered.
+.IP 1.
+The error due to sky noise in the aperture.
+.nf
+
+	$error sub 1 ~=~ sigma sub sky ~*~ {A sub apert} sup {1/2}$
+
+.fi
+.IP 2.
+The error in the aperture sum.
+.nf
+
+	$error sub 2 ~=~ ( {A sub "sum"  ~/~ phpadu} ) sup {1/2}$ 
+
+.fi
+.IP 3.
+The mean error of the sky.
+.nf
+
+	$error sub 3 ~=~ sigma sub sky ~*~ A sub apert ~/~ nsky sup {1/2}$
+
+
+.fi
+where $sigma sub sky$ is either computed by the background fitting
+algorithm or set by the user,
+and $A sub apert$ is the fractional pixel area of the
+aperture.
+
+.NH 4
+The WPHOT Algorithm
+.PP
+The WPHOT algorithm computes a weighted aperture sum in an attempt to
+minimize noise in the sky. The algorithm is the following where w is
+the weight for each pixel, p is the noise free profile value and 
+$sigma$ is the noise per pixel from all sources. (See the paper
+by Stover and Allen 1987 for details)
+.nf
+
+	$A sub sum ~=~ sum {w sub i ~*~ (I sub i ~-~ sky)}$
+
+	$w sub i ~=~ C ~*~ p sub i ~/~ sigma sup 2 sub i$
+
+	$C ~=~ sum {p sub j} / sum {p sub j ~*~ w sub j}$
+.fi
+
+.NH 4
+The POLYPHOT ROUTINES
+.PP
+The principal polyphot routines are the following.
+
+.nf
+\fL
+               apyinit (ap, sfunction, annulus, dannulus, noise)
+         ier = apfitcenter (ap, im, wx, wy)
+	 ier = aprefitcenter (ap)
+	 ier = apfitsky (ap, im, xcenter, ycenter, sd, gd)
+         ier = aprefitsky (ap, sd, gd)
+         ier = polyfit (ap, im, xver, yver, nver)
+       value = apstat[ir] (ap, param)
+               apstats (ap, param, str, maxch)
+               apset[sir] (ap, param, value)
+               apfree (ap)
+
+\fR
+.fi
+
+.PP
+.NH 4
+The POLYPHOT Algorithm 
+.PP
+The function of the POLYPHOT task is to compute the flux inside an
+irregular polygon given a list of the coordinates of the vertices of a polygon.
+The polygon must be entirely inside the image and the vertices of the polygon
+must be specified in clockwise or counterclockwise order.
+The actual algorithm used is as follows.
+.IP 1.
+The range of image lines which intersect the polygon are computed.
+.IP 2.
+For each image line in the specified range the intersection points with the
+polygon are computed.
+.IP 3.
+The flux between pairs of limits is summed using a fractional pixel
+approximation for the endpoints.
+.IP 4.
+The sky is fitted using any of the methods previously discussed and a
+user specified annular region.
+.IP 5.
+The errors are computed as specified in the PHOT specifications.
+.PP
+.EQ
+delim $$
+.EN
+
+.NH
+Example
+.PP
+A brief example may help illustrate the use of the package.  Suppose
+we want to process a few hundred stars on image "blue".
+.PP
+The first step is to prepare a list of objects to be measured.  The simplest
+way to do this is to interactively mark the objects with the image
+cursor using the display (graphics) device and the RIMCURSOR (RGCURSOR)
+task.
+.nf
+\fL
+
+	... load image on the display ...
+
+	ap> rimcursor > starlist
+
+	    ... move cursor and mark stars ...
+
+
+	... load contour plot on graphics terminal ...
+
+	ap> rgcursor > starlist
+
+	    ... move cursor and mark stars ...
+\fR
+.fi
+
+Alternatively one can run DAOFIND to compute a list of candidate objects
+in the frame.
+The name of the coordinate file is stored in the PHOT parameter set.
+
+.nf
+\fL
+	ap> phot.coords=starlist
+\fR
+.fi
+
+.PP
+The next step is to set up the PHOT parameters interactively.
+First we load the image (contour plot) blue on the display (graphics
+terminal). Next we call up PHOT in interactive mode.
+
+.nf
+\fL
+	ap> phot blue
+	... cursor appears ...
+
+\fR
+.fi
+
+.PP
+PHOT takes input by reading the image (graphics)
+display (terminal) cursor. In order to display the available commands
+we tap the ? key and the following text appears on the screen.
+
+.nf
+\fL
+	Interactive Phot Commands
+
+?	Print options
+:	Colon command see below
+i	Setup PHOT parameters interactively
+w	Write PHOT parameters to the parameter files
+l	Process the remainder of the coordinate list
+r	Rewind the coordinate list
+c	Fit center around the current cursor position
+t	Fit sky around the current cursor position
+s	Fit sky around the current center position
+p	Compute magnitudes around the cursor position
+f	Fit center, sky and compute magnitudes
+sp	Fit center, sky, compute magnitudes, and save
+q	Exit program
+
+Phot parameters are listed or set with the following commands.
+
+:m [n]	Move cursor to the [nth] object in the coordinate list
+:n [n]	Measure the [nth] object in the coordinate list
+
+:show [center/sky/phot/all]    List the aphot parameters
+:fwhmpsf [value]               Full width half maximum of the PSF
+:noise [string]                Noise model
+:threshold [value]             Threshold value for centering
+:sigma [value]                 Standard deviation of the background
+:ccdread                       CCD readout noise keyword
+:readnoise                     Readout noise in electrons
+:gain                          Gain keyword
+:epadu                         Electrons per adu
+
+:calgorithm [string]           Centering function
+:positive [y/n]                Emission or absorption feature
+:cbox [value]                  Width of the centering box in fwhmpsf
+:cmaxiter [value]              Maximum number of centering iterations
+:maxshift [value]              Maximum shift in fwhmpf
+:minsnratio [value]            Minimum signal to noise ratio of pixels
+:clean [y/n]                   Clean subraster before centering
+:rclip [value]                 Clipping radius in fwhmpsf
+:rclean [value]                Cleaning radius in fwhmpsf
+:kclean [value]                Sigma for clean algorithm
+:mkcenter [y/n]                Mark the centers on the display
+
+:salgorithm [string]           Sky fitting algorithm
+:annulus [value]               Inner radius of sky annulus in fwhmpsf
+:dannulus [value]              Width of sky annulus in fwhmpsf
+:skyvalue [value]              User supplied sky
+:smaxiter [value]              Maximum number of rejection cycles
+:skreject [value]              +/- Pixel rejection limits in sky sigma
+:snreject [value]              Maximum number of rejection interations
+:khist [value]                 +/- Sky histogram size in sky sigma
+:binsize [value]               Resolution of sky histogram in sky sigma
+:smooth [y/n]                  Lucy smooth the sky histogram
+:rgrow [value]                 Region growing radius in fwhmpsf
+:marksky [y/n]                 Mark the sky annuli on the display
+
+:weighting                     Weighting for wphot
+:aperts [string]               Aperture radii in fwhmpsf
+:zmag [value]                  Zero point of magnitude scale
+:exposure [string]             Exposure time keyword
+:itime [value]                 Integration time
+\fR
+.fi
+
+.PP
+We select the interactive setup option, move the image
+cursor to a high signal-to-noise, isolated star and tap the i key.
+PHOT responds by plotting the radial profile of the star on the
+screen and requesting the user to mark the fwhm of
+the psf, the centering aperture, the inner and outer sky annuli,
+the sky background and sigma and the set of circular apertures.
+The parameters so set can be examined and/or reset with the : commands as shown
+above. Sample measurements can be made of several stars by moving the
+cursor and typing the f command. Finally when we are happy with the
+parameter set we type w to store the parameters and q to exit the program.
+.PP
+Now we are ready to do photometry. We enter the PHOT program in batch mode.
+
+.nf
+\fL
+	ap> phot blue inter- &
+\fR
+.fi
+
+The batch job is now running, appending output lines to the file "blue.mag.#".
+We can proceed to set up the job for the red image, in much the same way
+that we set up the job for the blue image.  When both jobs finish, we
+can use the list processing tools to filter out the good objects and
+calculate colors.
+
+.NH
+The APPHOT Tasks
+.PP
+Manual pages for the APHOT tasks are attached. Although the working of the
+various tasks may change in detail, the help pages attached here should
+provide a good description of the function of each task.
+.PP
+When the package has stabilized a detailed users guide will be written.
diff --git a/noao/digiphot/apphot/doc/specs/apphot.spc.lw b/noao/digiphot/apphot/doc/specs/apphot.spc.lw
new file mode 100644
index 00000000..71285557
--- /dev/null
+++ b/noao/digiphot/apphot/doc/specs/apphot.spc.lw
@@ -0,0 +1,1296 @@
+.EQ
+delim $$
+.EN
+
+.RP
+.TL
+Specifications for the Aperture Photometry Package
+.AU
+Lindsey Davis
+.AI
+.K2 "" "" "*"
+Revised October 1987
+
+.AB
+The APPHOT package is a set of tasks for performing aperture photometry
+on uncrowded or moderately crowded fields, in either interactive or batch mode.
+The photometric technique employed is fractional pixel aperture
+integration. Point spread function fitting techniques are not used and no
+knowledge of the point spread function is required for the computation of
+magnitudes. Separate tasks are provided for creating and modifying object lists,
+computing accurate centers for a list of objects, computing sky values for
+a list of objects and performing aperture photometry inside circular or
+polygonal apertures.
+.AE
+
+.NH
+Introduction
+.PP
+The APPHOT package is a set of tasks for performing
+aperture photometry on uncrowded or moderately crowded fields.
+The photometric technique employed is fractional pixel integration. Point
+spread function techniques are not used and no knowledge of the point spread
+function is required for the computation of magnitudes.
+.PP
+The APPHOT package performs multi-aperture photometry on digitized starfields
+maintained as IRAF image files. Input to the package consists of an
+image file, a list of object coordinates, numerous parameters controlling
+the analysis algorithms and, optionally, the graphics terminal and/or
+display. APPHOT output consists of successive lines of text where each line
+summarizes the results of the analysis for a particular object.
+.PP
+Given starting coordinates and an IRAF image, the principal APPHOT
+task computes accurate centers, sky values and magnitudes
+for a list of objects.  Separate
+IRAF callable tasks in APPHOT exist to create and modify object
+lists, to determine image characteristics such as the full width half maximum
+of the point spread function or standard deviation of the sky pixels,
+to compute accurate centers for a list of objects, to compute accurate local sky
+values for a list of objects, and to compute magnitudes inside a polygonal
+aperture.
+
+.NH
+APPHOT Package Requirements
+.NH 2
+APPHOT Package Input
+.NH 3
+The IRAF Image
+.PP
+APPHOT assumes that images exist on disk in IRAF format. Facilities for reading
+and writing images exist elsewhere in IRAF such as in package DATAIO or
+MTLOCAL.
+.PP
+APPHOT assumes that the image data is linear.
+The input image is assumed to have been corrected for those instrumental
+defects which affect the intensity of a pixel. These include pixel to
+pixel variations in the bias values, pixel to pixel gain variations,
+cosmic rays, cosmetic defects, geometric distortion,
+and detector non-linearities.
+.PP
+APPHOT assumes that the local sky background is approximately flat in the
+vicinity of the object being measured. This assumption is equivalent to
+assuming that the local sky region has a unique mode. Therefore any
+variations in the sky background which occur at the same scale as the
+sky region should be removed prior to entering APPHOT.
+.PP
+The point spread function of the image is assumed to be constant for all
+regions of the image. This is particularly critical in the case of faint objects
+for which small apertures which minimize the effects of crowding and
+sky noise in the aperture are used. The wings of the object will
+almost certainly extend beyond the aperture and good results will only be
+obtained if
+objects are consistently well centered and the shape and diameter of an object
+is constant throughout the image and invariant to magnitude.
+
+.NH 3
+The Coordinate Lists
+.PP
+All APPHOT tasks operate on lists of object coordinates or interactive cursor
+input.  Lists are maintained as text files,
+one object per line with the x and y coordinates in
+columns one and two respectively. List files may be created interactively
+with either the graphics or image cursor, by a previously executed APPHOT
+task, by a previously executed IRAF task or by a user task.
+.PP
+The x and y coordinates contained in the list file can be either the
+starting centers for the objects of interest or the true centers.
+In either case the aperture centered around the object position must
+not extend beyond the boundary of the image. To obtain reliable results
+from the centering algorithm the starting centers should not be more than
+1 fwhmpsf pixels from the true centers.
+
+.NH 3
+Algorithm Parameters
+.PP
+Many tasks in the APPHOT package have an associated set of algorithm parameters
+which control the operation of the analysis routines. For example the
+centering and sky fitting algorithms each have an associated group of
+parameters.
+The APPHOT tasks supply reasonable defaults for these parameters. However
+the user may alter them at any time in interactive mode or by editing the
+appropriate parameter file before running the task in batch. 
+
+.NH 3
+Terminal Graphics and the Image Display
+.PP
+Most APPHOT programs may be run in either interactive or batch mode.
+In interactive mode, the user can mark the positions of objects by
+interactively, positioning the image cursor on the display device.
+Simple cursor commands can interactively alter the algorithm parameters. 
+In batch mode the algorithm parameters are
+fixed and object coordinates are taken from the user supplied coordinate list.
+The display device is not required in batch mode.
+.PP
+At present there is no high level IRAF display interface. Therefore the present
+version of APPHOT replaces the display device with terminal
+graphics. For example it is possible to load a contour plot of an image
+or image section, and run the APPHOT tasks, interactively marking
+positions on the plot. This is a temporary measure to tide thing over until
+the display interface is available. Furthermore this option is only
+really suitable for those terminal which have both text and graphics
+windows displayed at the same time.
+.PP
+Certain APPHOT tasks such as FITSKY occasionally require an interactive graphics
+capability. For example it is sometimes desirable to plot the histogram
+of the sky pixels and mark the peak of the histogram interactively rather
+than using the automatic sky fitting routines.
+Graphics capablity has been added to APPHOT tasks as deemed useful.
+
+.NH 2
+APPHOT Package Functions
+.NH 3
+Creating Coordinate Lists
+.PP
+APPHOT task(s) shall exist to create coordinate lists interactively within
+APPHOT by loading the IRAF image into the image display
+and successively marking the objects to be measured with the image cursor.
+It shall be possible to mark the positions of objects on the display, and draw
+circles of arbitrary size around the objects of interest.
+It shall be possible to verify existing coordinate lists by marking the object
+coordinates on the image display.
+.PP
+At present the full image display cababilities do not exist in IRAF.
+Therefore as a temporary measure most tasks will run with a contour
+plot and the graphics cursor as a substitute for the image display and
+image cursor by setting the image cursor to stdgraph and the display
+parameter for each task to stdgraph.
+The output coordinates will be written to a text file and may be used as
+starting coordinates for the APPHOT routines.
+.PP
+Those sites which have SUN workstations can use the IMTOOL facilites to
+create cursor lists.
+.PP
+APPHOT tasks shall exist to automatically detect objects by specifying the IRAF
+image to be searched, plus a few image characteristics such as a detection 
+threshold and the full width half maximum of the point spread function.
+The output coordinates plus a few object statistics  will be written to a
+text file.
+
+.NH 3
+Coordinate List Operations
+.PP
+General list processing tasks are or will be available in the IRAF lists
+package. Examples of useful currently existing tasks are list sorting by for
+example magnitude and performing a linear transformations
+on coordinate lists.
+.PP
+It may eventually be necessary to add some specialized list processing tasks
+to APPHOT. One example is a list matching facility in which objects in
+common to two lists are combined and output to a third list.
+
+.NH 3
+Determining the Image Characteristics
+.PP
+APPHOT tasks shall exist to estimate certain image
+characteristics such as the full width half maximum of the image point spread
+function and the standard deviation of the background. In order to obtain
+meaningful error estimates it is also necessary to specify the noise
+charactersitics of the detector and a noise model.
+In this version of APPHOT two noise
+functions will be supported a constant sky background noise,
+and constant background noise plus Poisson statistics in the object.
+.PP
+The reason for this capability is that the majority of the APPHOT
+algorithm parameters scale with these two image characteristics.
+For example all the pixel scale dependent parameters such as the centering
+aperture, object apertures, the two sky annuli and the
+maximum shift parameter all scale with the full width half
+maximum of the point spread function. Similarly most of the pixel intensity
+dependent parameters scale with the standard deviation of the sky pixels.
+
+.NH 3
+Centering
+.PP
+An APPHOT task shall exist to determine accurate centers for a list of objects,
+using the approximate object coordinates as a starting point.
+The centering aperture may extend beyond the boundaries of the image but
+a warning message will be generated.
+.PP
+A choice of centering algorithms with a range of efficiency and accuracy will
+be available.  The center determination must be resistant to the affects of
+nearby contaminating objects.
+.PP
+The user may opt to use the starting center as the actual center in all cases,
+to use the starting center as the actual center if the object is very faint,
+or tweak up the center if the signal to noise is above a certain threshold.
+.PP
+The output of the centering algorithm will the set of computed coordinates
+and their errors.
+
+.NH 3
+Fitting the Sky
+.PP
+An APPHOT task shall exist to compute a constant background value by analysis
+of an annular region surrounding the object.
+The background is assumed to be flat in the region
+of the object, but may contain contaminating objects or defects which
+shall be detected and eliminated by the fitting algorithm.
+It shall be permissible for the background region to extend beyond the
+boundaries of the image; the out of bounds region of the background shall
+be excluded from the fit.
+.PP
+The user may supply a constant background, with zero-valued noise and skew
+value or read appropriate values from a file instead of computing the
+background.
+.PP
+The output of the sky fitting algorithm shall be
+the mode, standard deviation and skew of the sky as well as the number
+of pixels left in the background region after pixel rejection and the number
+rejected.
+
+.NH 3
+Multi-aperture Photometry
+.PP
+APPHOT routines shall exist to compute the integral of object minus background
+within one or more circular apertures centered upon the object.
+The integration shall be
+performed using partial pixel techniques, to minimize the effects of
+sampling.  If the aperture contains any indefinite pixels, or if the
+aperture extends beyond the boundary of the image, an indefinite result
+shall be returned. Both normal and weighted photometry routines shall
+be available.
+.PP
+It shall be possible to normalize the output magnitudes to a user specified
+integration time using values stored in the IRAF image header.
+.PP
+The output shall consist of magnitudes and errors for each of the specified
+apertures.
+.NH 3
+Polygonal Aperture Photometry
+.PP
+Determine the integral of the object within a specified
+polygon. Aperture integration shall be by fractional pixel summation
+of successive image lines.
+
+.NH
+Specifications
+.NH 2
+Apphot CL Callable Tasks
+.PP
+The CL callable part of the APPHOT package consists of the following
+routines:\f(CW
+
+.nf
+.na
+        mark    -- create/verify coordinate lists interactively
+    polymark    -- create/verify polygon lists interactively
+     daofind    -- automatic image finder from DAOPHOT
+     lintran    -- linearly transform a list of coordinates (LISTS package)
+
+     radprof    -- compute the radial profile of an object.
+      fitpsf    -- model the PSF
+
+      center    -- compute accurate centers for a list of objects
+      fitsky    -- compute accurate sky values for a list of objects
+        phot    -- perform multi-aperture photometry on a set of objects
+    polyphot    -- compute the flux inside a set of irregular polygons
+       wphot	-- perform weighted multi-aperture photometry\fR
+.ad
+.fi
+
+.NH 2
+Standard Analysis Procedures
+.PP
+A standard reduction procedure would be something as follows.
+.IP 1.
+Estimate the image and data characteristics in the following manner.
+.RS
+.IP 1.
+Use the interactive setup option (i key) in the PHOT task to specify the
+fwhm of the psf,
+the centering apperture, the sky annuli, the photometry apertures as
+well as estimate the sky sigma.
+Examine the results (:show command) and optionally store the 
+new parameters in the parameter files (w key).
+.IP 2.
+Use the EPAR task to edit the parameter files directly. For example the
+detector gain and readout noise must be known before running PHOT in
+order to get reliable error estimates.
+.RE
+.IP 2.
+Prepare a coodinate list in one of the following ways.
+.RS
+.IP 1.
+Running MARK or POLYMARK.
+.IP 2.
+Run DAOFIND or some other automatic image finder.
+.IP 3.
+Run another APPHOT task such as CENTER .
+.IP 4.
+Run any other IRAF or user program which generates the appropriate
+format.
+.IP 5.
+Transform an existing list using the LISTS package facilities
+.RE
+.IP 3.
+Run PHOT or WHOT in non-interactive mode to perform the multi-aperture
+photometry.  The user should be familiar
+with the algorithms used to measure the object center, to fit the background,
+and compute the aperture integral, magnitude, and errors.  The values of
+all visible and hidden PHOT parameters should be inspected before doing
+any serious processing. Note that CENTER and FITSKY can be run independently
+of PHOT and their output used as input to PHOT.
+.EQ
+delim $$
+.EN
+
+.NH 2
+The APPHOT Algorithms
+.PP
+The principal APPHOT algorithms are described below.
+
+.NH 3
+The RADPROF Algorithm
+.PP
+The function of the RADPROF task is to compute the radial profile of
+selected, isolated, high signal to noise objects in an IRAF image.
+.PP
+Given the IRAF image, an initial center, an aperture and a step size,
+RADPROF computes the radial profile of an object in the following manner.
+.IP 1.
+The APPHOT centering routines are used to compute an accurate center for the
+object. The new center is used to compute the radial coordinate for each
+pixel in the subraster.
+.IP 2.
+The APPHOT sky fitting routines are used to compute an accurate sky value
+for the object. The new sky value is used to compute the object intensity
+for each pixel in the subraster.
+.IP 3.
+The CURFIT package routines are used to produce a smooth intensity versus
+radius curve by fitting a cubic least squares spline function to the data
+using linear least squares techniques.
+.IP 4.
+The fitted curve is evaluated at equally spaced intervals to produce the
+final radial profile. The profile is normalised using the r = 0 value.  
+.IP 5.
+The smoothed curve is integrated using the 
+1D integration routines IMINTERP to evalute the fraction of the total
+integral at each interval.
+.IP 6.
+The three quantities $I sub r$ the raw intensity, $Inorm sub r$ the
+normalized intensity, and $Ifraction sub r$ the fraction of the total
+intensity inside radius at r,  are plotted on the terminal and
+output as a function of r to a text file.
+.PP
+RADPROF is used principally to compute the stellar image and setup the
+parameters for doing photometry. Its default output is a radial profile
+plot with the phot parameters marked on it.
+
+.NH 3
+The FITPSF Algorithm
+.PP
+The function of the FITPSF task is to fit an analytic model to an object
+in order to derive information about the point spread function. Given
+an IRAF image, an initial center and an aperture, FITPSF computes the
+model parameters in the following manner.
+.IP 1.
+The fitting function is chosen.
+The present version of FITPSF offers two function choices a 2D radial Gaussian
+function and an elliptical Gaussian function.
+A third option, moment analysis, has been added to the FITPSF package.
+The image characteristics are evaluted by using the 0th, 1st and 2nd order
+moments of the image.
+.IP 2
+Initial guesses for the parameters are made from the subraster data.
+.IP 3
+The parameters and their errors are derived using standard non-linear least
+squares techniques and the NLFIT package.
+
+.NH 3
+The DAOFIND Algorithm
+.PP
+The function of the DAOFIND task is to automatically detect objects
+in an IRAF image above a certain intensity threshold.
+The user specifies an intensiyt threshold,
+the estimated full width half maximum of
+the point spread function,
+and limits on the sharpness and roundness of the objects to be detected.
+DAOFIND produces a list of x and y coordinates and a sharpness
+and roundness statistic for each detected object.
+.PP
+The DAOFIND algorithm works in the following way.
+.IP 1.
+The user specifies an intensity threshold above local sky and estimates
+the full width half maximum of the point spread function.
+.IP 2.
+DAOFIND computes a convolution kernel which is a linear
+function of the brightness values in an approximately circular array of
+pixels.  The original data is convolved with the computed kernel.
+The equivalent mathematical
+operation is a convolution of the original data
+with truncated, lowered circular Gaussian function with the specified FWHM,
+computed in such a way as to be the mathematical
+equivalent of fitting a Gaussian stellar profile to the object data by least
+squares. The coefficients of the linear function sum to zero so that the
+overall bias level (local sky) cancels out exactly. Since the function is
+symmetric about a single pixel, a smooth gradient in the sky brightness
+also cancels exactly. Therefore the user does not have to specify an
+absolute brightness threshold but only a threshold above local sky.
+.IP 3
+The convolved data is searched for local maxima. Local maxima which are
+less than the specified threshold are rejected. A pixel is defined to be
+a local maximum when it is the brightest pixel within
+$n ~*~ sigma sub Gauss$.
+.IP 4.
+Using the original data, DAOFIND computes an object sharpness statistic which
+can be used to reject
+hot or cold pixels.  The sharp parameter is defined below.
+Detected  objects with a sharpness parameter outside the range specifed
+by sharplo and sharphi are rejected. Typical values for sharplo and
+sharphi are 0.2 and 1.0 respectively.
+.nf
+
+    $I sub delta$ = height of best fitting $delta$ function = pixel value
+
+    $I sub Gauss$ = height of best fitting Gaussian function = convolved value
+
+    sharplo <= sharp = ${I sub delta} over {I sub Gauss}$ <= sharphi
+
+.fi
+If the brightness enhancement detected in the convolved data is due to
+a single bright pixel, then the best fitting delta function will have an
+amplitude equal to the height of this pixel above the local background,
+while the amplitude of the best fitting Gaussian will be pulled down by
+the surrounding low valued pixels. Sharp will be a number significantly
+greater than one. A single cold pixel will produce
+brightness enhancements approximately 0.5 * FWHM away
+from the pixel in question  in all directions. In this case the height
+of the delta
+function which best fits these spurious maxima is close to zero, while the
+height of the best fitting Gaussian is some small positive number.
+In this case sharp will be close to zero.
+.IP 5.
+The roundess statistic is computed from the original picture data by fitting
+1D Gaussians
+to the marginal sums in x and y. If the height of either 1D
+Gaussian is negative the object is rejected. If both heights are
+positive the roundness parameter is computed.
+.nf
+
+	$DELTA I ~=~ I sub {x ~ Gauss} ~-~ I sub {y ~ Gauss}$
+
+	$<I> ~=~ I sub {x ~ Gauss} ~+~ I sub {y ~ Gauss}$
+
+	$roundlo ~<=~  round ~=~ {DELTA I} over <I> ~<=~  roundhi$
+
+.fi
+Objects which are elongated in the
+x direction have roundness values less than zero and those elongated in
+the y direction have roundness greater than zero.
+Round discriminates only against objects which are elongated
+along either rows or columns. Objects elongated at a 45 degree angle will
+not be rejected.
+.IP 6.
+Finally the approximate x and y centroids of the detected objects,
+rough magnitudes relative to threshold are computed, and object is added
+to the output file.
+
+
+.NH 3
+The CENTER Task
+
+.NH 4
+Centering Package Routines
+.PP
+The following are the principal programmer callable routines routines in the
+centering package.
+.nf
+\f(CW
+
+                  apcinit (ap, cfunction, cbox, fwhmpsf, noise)
+            ier = apfitcenter (ap, im, xinit, yinit)
+            ier = aprefitcenter (ap)
+          value = apstat[ir] (ap, param)
+                  apstats (ap, param, str, maxch)
+                  apset[sir] (ap, param, value)
+                  apcfree (ap)
+
+\fR
+.fi
+.PP
+The following quantities can be examined or set by apstat/apset calls
+.nf
+\f(CW
+  data          1. fwhmpsf       full width half maximum of psf in pixels
+parameters      2. threshold     minimum intensity for centering
+                3. noise         noise model
+                4. sigma         standard deviation of background
+                5. readnoise     readout noise of CCD in electrons
+                6. epadu         electrons per adu
+
+centering       1. calgorithm    centering algorithm
+parameters      2. positive      emission / absorption features
+                3. cbox          centering radius in fwhmpsf
+                4. cmaxiter      maximum number of fitting iterations
+                5. maxshift      maximum permitted shift in fwhmpsf
+                6. minsnratio    minimum permitted signal to noise ratio
+                7. clean         clean subraster before centering
+                8. rclean        cleaning radius in fwhmpsf
+                9. rclip         clipping radius in fwhmpsf
+                10.kclean        k-sigma rejection for cleaning in sigma
+\fR
+.fi
+
+.PP
+The following computed quantities can be examined by apstat calls.
+.nf
+\f(CW
+              1. xcenter            computed x coordinate
+              2. ycenter            computed y coordinate
+              3. xerr               computed x coordinate error
+              4. yerr               computed y coordinate error
+\fR
+.fi
+.PP
+See the manual pages for CENTER and CENTERPARS for a detailed description
+of the centering parameters.
+
+.NH 4
+The Centering Algorithm
+.PP
+The function of the CENTER task is to compute accurate centers and errors
+for objects in an IRAF image given a list of initial positions and a
+centering aperture.
+.IP 1.
+If the centering algorithm is disabled, the computed center is set to the
+initial center and the uncertainty estimate is set to zero.
+.IP 2.
+If the cleaning algorithm is enabled, clean the subraster before centering.
+.IP 3.
+Estimate is made of the signal to noise of the object. If this quantity is
+less than a certain minimum value the computed center is kept
+but a warning message is issued.
+.IP 4.
+The center and errors are computed using one of several algorithms.
+.IP 5.
+If the computed center is greater than a user specified distance from the
+initial center then the computed center is returned with an error
+message.
+
+.NH 4
+Symmetry Clean Algorithm
+.PP
+The symmetry-clean algorithm attempts to remove defects in the centering
+subraster by assuming that the object has radial symmetry and comparing
+pixels on the opposite sides of the center of symmetry. The algorithm
+works in the following way.
+.IP 1.
+The center of symmetry is computed. Normally the center of symmetry is assumed
+to coincide with the position of the brightest pixel in the subarray.
+However if the maximum pixel is more than a user specified distance away
+from the intial center, the initial center is used as the center of symmetry.
+.IP 2.
+Pixels inside a specified cleaning radius are unaltered.
+.IP 3.
+Pairs of pixels diametrically opposed about the center
+in the cleaning region between the cleaning and clipping
+radii are tested for equality.  If the difference between the pixels is
+greater than a specified k-sigma rejection limit, the larger value is replaced
+by the smaller.
+In this region sigma is computed from Poisson statistics.
+.IP 4.
+Pairs of pixels in the clippping
+region are compared in the same manner as those in the cleaning region
+except that sigma is the standard deviation of the sky pixels.
+.PP
+The effect of the symmetry-clean algorithm is to edit the raster,
+removing any contaminating objects in the vicinity of the primary object.
+This simplifies the fitting algorithm and increases its reliability,
+since it does not have to deal with multipeak marginal distributions.
+
+.NH 4
+Signal to Noise Estimate
+
+.PP
+The signal to noise of the object is estimated from the data values
+in the subraster in the following way.
+.nf
+
+	$SNR ~=~ N sub object over {sqrt {n sub pix ~*~sigma sub sky sup 2}}$
+
+		or
+
+	$SNR ~=~ N sub object over {sqrt {N sub object ~+~ n sub pix~*~sigma sub sky sup 2}}$
+
+.fi
+where $N sub *$ is the number of counts in the object above threshold,
+$sigma sub sky$
+is the standard deviation of the pixels in the sky region and
+$n sub pix$ is the number of pixels in the object aperture.
+The first approximation corresponds to constant sky noise only,
+the second includes Poisson noise in the object.
+
+.NH 4
+Centroid
+.PP
+The centroid centering algorithm is similar to that used in MPC and can
+be briefly described as follows. For more detailed description
+see (Stellar Magnitudes From Digital Pictures, 1980, Adams et al).
+.IP 1.
+The marginal distributions in x and y are accumulated.
+.IP 2.
+The intensity weighted centroid positions for the marginals is computed
+using only data pixels which are above the threshold intensity. If the
+threshold parameter is 0 the mean intensity of the marginal is used
+in place of the threshold
+.nf
+
+    $I sub i ~=~ I sub i ~-~ threshold ~~~~~ I sub i ~>~ 0.0$
+
+    $x sub c ~=~ {sum I sub i ~ x sub i} over {sum I sub i}$
+
+.fi
+.IP 3.
+The errors are estimated in the following way
+.nf
+
+    $sigma sup 2 ~=~ {sum I sub i ~ x sub i sup 2} over {sum I sub i} ~-~ x sub c sup 2$
+
+    $err sub xc ~=~ sqrt {{sigma sup 2} ~/~ sum I sub i}$
+
+.fi
+
+.NH 4
+Gaussian Fit to the Marginals
+.PP
+The fit is performed in the following way.
+.IP 1.
+The  marginal distributions in x and y are accumulated.
+.IP 2.
+Initial guesses for the parameters of the 1D Gaussians $I sub Gauss$,
+$x sub c$ and $I sub sky$ are derived from the marginal distributions
+themselves. The width $sigma$ is held constant.
+.IP 3.
+The best fit parameters and their errors are derived using non-linear
+least-squares techniques and the NLFIT package.
+
+.NH 4
+Optimal Filtering of Marginals
+.PP
+The fit is performed is the following way.
+.IP 1.
+The marginal distributions in x and y are accumulated.
+.IP 2.
+The centroid of the observed distribution is computed by solving the
+following equation.
+.nf
+
+        $PSI (x sub c ) ~=~ sum omega sub i (x sub c ) ~ PHI sub i ~=~ 0$
+
+        $omega sub i ~=~ {{partial phi sub i} ~/~ {partial x sub c}} over {phi sub i~+~b}$
+
+.fi
+The assumptions are that the observed distribution $PHI sub i$ is correctly
+modeled by the profile function $phi sub i$. The usual choise of profile
+model for centering is a Gaussian. Howver in the interests of speed a triangle
+function has been substituted. This causes at most a 7% increase in the
+random centering error.
+.IP 3.
+The startup procedure is based on the following fact.
+.nf
+
+	$PSI (x sub n )~>~0~~for~~ x sub n ~<~ x sub c$
+
+	$PSI (x sub n ) ~<~0~~for~~ x sub n ~>~ x sub c$
+
+.fi
+The iteration is initialized by assuming that $x sub 1$ = $x sub c$ and
+computing $PSI (x sub 1 )$. The initial x 
+value is incremented by $+- sigma sub Gauss$ depending on the sign of $PSI$. The
+search is repeated until $PSI (x sub {n-1})$ and $PSI (x sub n)$ have
+opposite signs. At this point the true center is bracketed by the
+estimated positions $(x sub n, ~ x sub {n-1})$ and we have a table of at
+least 2 values of $PSI (x sub n )$.
+.IP 4.
+The computation proceeds by interpolating in the table of values for the
+estimated position $x sub {n+1}$ where $PSI$ = 0. If the table contains only
+two values as may be the case for the inititial interpolation, linear
+interpolation is used. In all other cases a quadratic fit to the three
+most recent $PSI$ values is used. The computation is complete when
+two successive estimates differ by less than some tolerance typically
+0.001 pixel.
+.IP 5.
+The errors are estimated as follows.
+.nf
+
+    $sigma sup 2 ~=~ ( {int {( partial phi ~/~ partial x sub c )} sup 2 over {
+    phi + b}} ) sup -1$
+
+    $err sub xc ~=~ sqrt {sigma sup 2}$
+
+.fi
+
+.NH 4
+Other Centering Methods
+.PP
+The code is constructed in such a way that new algorithms may be
+easily added at a future date, such as the more sophisticated techniques
+required for accurate astrometry.
+.EQ
+delim $$
+.EN
+.NH 3
+The FITSKY Task
+
+.NH 4
+Sky Fitting Routines
+
+.PP
+The following are the main entry points in the sky fitting package.
+.nf
+\f(CW
+         apsinit (ap, function, annulus, dannulus, fwhmpsf, noise)
+   ier = apfitsky (ap, im, xpos, ypos, sd, gd)
+   ier = aprefitsky (ap, sd, gd)
+ value = apstat[ir] (ap, param)
+         apstats (ap, param, str, maxch)
+         apset[irs] (ap, param, value)
+         apsfree (ap)
+\fR
+.fi
+.PP
+The following quantities can be examined or set with apset/apstat calls.
+.nf
+\f(CW
+data             1. fwhmpsf     full width half maximum of the psf
+parameters       2. sigma       standard deviation of sky pixels
+
+sky fitting      1. annulus     inner radius of sky annulus in fwhmpsf
+parameters       2. dannulus    outer radius of sky annulus in fwhmpsf
+                 3. sfunction   sky fitting algorithm
+                 4. smaxiter    maximum number of fitting iterations
+                 5. kreject     k-sigma rejection limit sigma
+                 6. nreject     maximum number of rejection cycles
+                 7. rgrow       region growing radius in fwhmpsf
+
+                 8. khist       half-wdth of histogram in sigma
+                 9. binsize     binsize of histogram in sigma
+                 10.smooth      Lucy smooth the histogram
+
+                 11.skyfile     name of text file containing sky values
+                 12.skyvaluser  supplied constant value for sky
+\fR
+.fi
+.PP
+The following computed quantities can only be examined with apstat calls.
+.nf
+\f(CW
+              1. skymode           computed sky value
+              2. skysig            computed sky sigma
+              3. skyskew           computed sky skew
+              4. nsky              number of sky pixels
+              5. nsky_reject       number of rejected sky pixels   
+\fR
+.fi
+
+.NH 4
+The Sky Fitting Algorithms
+.PP
+A good background fit is essential to aperture photometry.  Fitting
+the background is trivial in a sparse field, but difficult in a crowded
+field.  In general the background region will contain contaminating objects
+which must be detected and excluded if a good fit is to be obtained.
+.PP
+The main algorithm used in APPHOT is the following.
+.IP 1.
+If the skyfitting switch is disabled either read the sky values from a text
+file or accept a user supplied constant for the sky.
+.IP 2.
+Perform the initial sky fit using one of the specified algorithms. The
+sky fitting algorithms fall into three general categories, those that use
+the actual sky pixel array itself, those that operate on a histogram of
+sky values and those that rely on user interaction.
+.IP 3.
+If the pixel rejection flags are set perform pixels rejection with optional
+region growing.
+
+.NH 4
+Sky Pixel Array Techniques
+
+.NH 5
+Median
+.IP 1.
+Sort the array of sky pixels. This is necessary to avoid quantization effects.
+.IP 2.
+Compute the median, and the standard deviation and skew with respect to the
+mean.
+.IP 3.
+If the k-sigma rejection limit is greater than zero and the maximum number
+of rejection cycles is greater than one, perform pixel rejection.
+Pixels greater than k-sigma from the median are rejected. Region growing
+is optional.
+.IP 4.
+Stop the rejection cycle on any given iteration if the maximum number of
+rejection cycles ix exceeded, no more sky pixels are left or no more
+pixels are rejected.
+
+.NH 5
+Mode
+.IP 1.
+Sort the array of sky pixels. This is necessary to avoid quantization effects.
+.IP 2.
+Compute the mode, and the standard deviation and skew
+with respect to the mean.
+.nf
+
+	$I sub mode ~=~ 3.0 ~*~ I sub median ~-~ 2.0 ~*~ I sub mean$
+
+.fi
+.IP 3.
+If the k-sigma rejection limit is greater than zero and the maximum number
+of rejection cycles is greater than one, perform pixel rejection.
+Pixels greater than k-sigma from the mode are rejected. Region growing
+is optional.
+.IP 4.
+Stop the rejection cycle on any given iteration if the maximum number of
+rejection cycles ix exceeded, no more sky pixels are left or no more
+pixels are rejected.
+
+
+.NH 4
+Histogram Techniques
+.PP
+The following three techniques all operate on the histogram of the sky pixels.
+The routines all construct the histogram in the following identical manner.
+.IP 1.
+The mean of the sky distribution is computed.
+.IP 2.
+If the user specified standard deviation of the sky pixels is INDEF the
+algorithm computes the standard deviation of the sky pixels with respect
+to the mean.
+.IP 3.
+All pixels within plus or minus sigma standard
+deviations are accumulated into a histogram. The user specifies the bin size.
+.IP 4.
+The histogram may optionally be Lucy smoothed before any operation is performed
+on it.
+
+.NH 5
+Centroid
+.PP
+The mode, sigma and skew of the sky pixels are computed in the following
+manner.
+.IP 1.
+The histogram is compiled as above.
+.IP 2.
+The mode, standard deviation and skew of the sky pixels are computed in the
+following manner.
+
+.nf
+    $I sub 0 ~=~ sum I sub i$
+    $I sub 1 ~=~ sum I sub i ~ x sub i$
+    $I sub 2 ~=~ sum I sub i ~ x sub i sup 2$
+    $I sub 3 ~=~ sum I sub i ~ x sub i sup 3$
+
+    $I sub mode ~=~ {I sub 1} ~/~ {I sub 0}$ 
+    $sigma ~=~ {( I sub 2 ~/~ I sub 0 ~-~ I sub mode sup 2 )} sup {1/2}$
+    $skew ~=~ ( {I sub 3 ~/~ I sub 0 ~-~ I sub mode ~*~ sigma sup 2 ~-~ I sub mode sup 3} ) sup {1/3}$
+
+.fi
+.IP 3
+If pixel rejection is enabled sky pixels within a user supplied limit of
+the mode are rejected with optional region growing.
+
+.NH 5
+Gaussian Fit
+.PP
+The mode, standard deviation and skew of the sky pixels are derived from a
+model fit in the following way.
+.IP 1.
+The histogram of the sky pixels is compiled as above. 
+.IP 2.
+Initial guesses to the model parameters, $N sub max$, $I sub mode$,
+$sigma$, and $skew$ are made from the histogram itself.
+.IP 3.
+Final parameters and their errors are derived using non-linear least squares
+techniques and the NLFIT package.
+.IP 4.
+If pixel rejection is enabled sky pixels within a user supplied limit of
+the computed mode are rejected with optional region growing.
+
+.NH 5
+Optimal Filtering
+.PP
+The method is as follows.
+.IP 1.
+The histogram is compiled as above.
+.IP 2.
+Using the mean of the sky pixels as the intital value of the sky mode,
+a new mode is computed using the optimal filtering technique
+described for centering.
+.IP 4
+If pixel rejection is enabled sky pixels within a user supplied limit of
+the computed mode are rejected with optional region growing.
+
+.NH 5
+Cross Correlation
+.PP
+The method is as follows.
+.IP 1.
+The histogram is compiled as above.
+.IP 2.
+The noise function is estimated using the standard deviation of the sky
+pixels and the cross-correlation function is computed.
+.IP 3.
+The mode is computed using quadratic interpolation around the peak of the
+distribution.
+.IP 4
+If pixel rejection is enabled sky pixels within a user supplied limit of
+the mode are rejected with optional region growing.
+
+.NH 4
+Interactive Techniques
+
+.NH 5
+Histogram Plot
+.PP
+The histogram is compiled as described above and the user marks the peak
+on the histogram plot with the graphics cursor. The sigma and skew of the
+sky distribution with respect to the mean is also computed.
+
+.NH 5
+Radial Distribution
+.PP
+A radial profile plot of the sky region is plotted and the user marks the
+sky value on the plot with the graphics cursor. The sigma and skew of the sky
+distribution with respect to the mean is computed.
+
+.NH 4
+Pixel Rejection and Region Growing
+.PP
+All the sky fitting algorithms permit pixel rejection and
+optional region growing.
+Pixel rejection  and region growing are
+performed by locating all pixels more than k * sigma from the mode,
+and blindly rejecting all pixels within a certain radius of each deviant
+pixel.  This simple algorithm works well because the sample is large,
+and therefore there is little penalty for discarding pixels that might
+not be deviant.  Region growing also tends to accelerate convergence
+significantly.
+.PP
+Very faint contaminating objects are difficult to detect and reject.
+If there are enough such objects, they should not be rejected, because
+there are probably a few in the object aperture as well.  A higher sky
+sigma will be calculated and the computed uncertainty in the magnitude
+will increase.  The best solution to this problem may be to increase
+the size of the annulus to minimize the bias.
+
+.NH 4
+The Principal PHOT Routines
+.PP
+The main entries in the photometry routine are the following.
+.nf
+\f(CW
+               apinit (ap, cfunction, cbox, sfunction, annulus, dannulus,
+                aperts, napert, fwhmpsf, noise)
+         ier = apfitcenter (ap, im, xinit, yinit)
+         ier = aprefitcenter (ap)
+         ier = apfitsky (ap, im, xcenter, ycenter, sd, gd)
+         ier = aprefitsky (ap, sd, gd)
+         ier = apmag (ap, im, xcenter, ycenter, skyval, skysig, nsky)
+         ier = apwmag (ap, im, xcenter, ycenter, positive, skyval, skysig,
+                nsky)
+         ier = apremag (ap, positive, skyval, skysig, nsky)
+         ier = apwremag (ap, positive, skyval, skysig, nsky)
+       value = apstat[ir] (ap, param)
+               apstats (ap, param, str, maxch)
+               apset[sir] (ap, param, value)
+               apfree (ap)
+
+\fR
+.fi
+.PP
+The following parameters can be examined or altered by apset/apstat calls.
+.nf
+\f(CW
+                1. weighting        weighting scheme for wphot
+                2. aperts           list of apertues
+                3. naperts          number of apertures
+                4. zmag             zero point of magnitude scale
+                5. itime            effective integration time
+\fR
+.fi
+.PP
+The following quantities can be examined with apstat calls.
+.nf
+\f(CW
+
+                1. sums            array of aperture sums
+                2. areas            array of areas
+                3. mags             array of magnitudes
+                4. magerrs          array of magnitude errors
+
+\fR
+.fi
+
+.NH 4
+The PHOT Aperture Integration Algorithm
+.PP
+The integral of the flux within a circular aperture is computed by
+fractional pixel techniques.  Pixels are assumed to be square apertures
+arranged in a rectangular grid.  The fraction of a pixel which lies within
+the circular APPHOT aperture is computed by an approximation, and all
+such contributions are summed to produce the total integral.
+.PP
+The inclusion of a partial pixel inside the aperture is done as follows.
+.IP 1.
+If the distance of the current pixel from the center of the star, r, is
+exactly equal to the radius of the aperture R then one-half the counts in
+the pixel are included.
+.IP 2.
+If r < R - 0.5 the entire pixel is included while if r > R + 0.5 the pixel
+is wholly excluded.
+.IP 3.
+In between the fraction of the counts varies linearly. A circular aperture
+is approximated by an irregular polygon.
+.PP
+The simplicity of aperture photometry limits the amount of information
+available for error analysis.  The following three sources of error are
+considered.
+.IP 1.
+The error due to sky noise in the aperture.
+.nf
+
+	$error sub 1 ~=~ sigma sub sky ~*~ {A sub apert} sup {1/2}$
+
+.fi
+.IP 2.
+The error in the aperture sum.
+.nf
+
+	$error sub 2 ~=~ ( {A sub "sum"  ~/~ phpadu} ) sup {1/2}$ 
+
+.fi
+.IP 3.
+The mean error of the sky.
+.nf
+
+	$error sub 3 ~=~ sigma sub sky ~*~ A sub apert ~/~ nsky sup {1/2}$
+
+
+.fi
+where $sigma sub sky$ is either computed by the background fitting
+algorithm or set by the user,
+and $A sub apert$ is the fractional pixel area of the
+aperture.
+
+.NH 4
+The WPHOT Algorithm
+.PP
+The WPHOT algorithm computes a weighted aperture sum in an attempt to
+minimize noise in the sky. The algorithm is the following where w is
+the weight for each pixel, p is the noise free profile value and 
+$sigma$ is the noise per pixel from all sources. (See the paper
+by Stover and Allen 1987 for details)
+.nf
+
+	$A sub sum ~=~ sum {w sub i ~*~ (I sub i ~-~ sky)}$
+
+	$w sub i ~=~ C ~*~ p sub i ~/~ sigma sup 2 sub i$
+
+	$C ~=~ sum {p sub j} / sum {p sub j ~*~ w sub j}$
+.fi
+
+.NH 4
+The POLYPHOT ROUTINES
+.PP
+The principal polyphot routines are the following.
+
+.nf
+.na
+\f(CW
+               apyinit (ap, sfunction, annulus, dannulus, noise)
+         ier = apfitcenter (ap, im, wx, wy)
+         ier = aprefitcenter (ap)
+         ier = apfitsky (ap, im, xcenter, ycenter, sd, gd)
+         ier = aprefitsky (ap, sd, gd)
+         ier = polyfit (ap, im, xver, yver, nver)
+       value = apstat[ir] (ap, param)
+               apstats (ap, param, str, maxch)
+               apset[sir] (ap, param, value)
+               apfree (ap)
+
+\fR
+.ad
+.fi
+
+.PP
+.NH 4
+The POLYPHOT Algorithm 
+.PP
+The function of the POLYPHOT task is to compute the flux inside an
+irregular polygon given a list of the coordinates of the vertices of a polygon.
+The polygon must be entirely inside the image and the vertices of the polygon
+must be specified in clockwise or counterclockwise order.
+The actual algorithm used is as follows.
+.IP 1.
+The range of image lines which intersect the polygon are computed.
+.IP 2.
+For each image line in the specified range the intersection points with the
+polygon are computed.
+.IP 3.
+The flux between pairs of limits is summed using a fractional pixel
+approximation for the endpoints.
+.IP 4.
+The sky is fitted using any of the methods previously discussed and a
+user specified annular region.
+.IP 5.
+The errors are computed as specified in the PHOT specifications.
+.PP
+.EQ
+delim $$
+.EN
+
+.NH
+Example
+.PP
+A brief example may help illustrate the use of the package.  Suppose
+we want to process a few hundred stars on image "blue".
+.PP
+The first step is to prepare a list of objects to be measured.  The simplest
+way to do this is to interactively mark the objects with the image
+cursor using the display (graphics) device and the RIMCURSOR (RGCURSOR)
+task.
+.nf
+\f(CW
+
+	... load image on the display ...
+
+	ap> rimcursor > starlist
+
+	    ... move cursor and mark stars ...
+
+
+	... load contour plot on graphics terminal ...
+
+	ap> rgcursor > starlist
+
+	    ... move cursor and mark stars ...
+\fR
+.fi
+
+Alternatively one can run DAOFIND to compute a list of candidate objects
+in the frame.
+The name of the coordinate file is stored in the PHOT parameter set.
+
+.nf
+\f(CW
+	ap> phot.coords=starlist
+\fR
+.fi
+
+.PP
+The next step is to set up the PHOT parameters interactively.
+First we load the image (contour plot) blue on the display (graphics
+terminal). Next we call up PHOT in interactive mode.
+
+.nf
+\f(CW
+	ap> phot blue
+	... cursor appears ...
+
+\fR
+.fi
+
+.PP
+PHOT takes input by reading the image (graphics)
+display (terminal) cursor. In order to display the available commands
+we tap the ? key and the following text appears on the screen.
+
+.nf
+\f(CW
+	Interactive Phot Commands
+
+?	Print options
+:	Colon command see below
+i	Setup PHOT parameters interactively
+w	Write PHOT parameters to the parameter files
+l	Process the remainder of the coordinate list
+r	Rewind the coordinate list
+c	Fit center around the current cursor position
+t	Fit sky around the current cursor position
+s	Fit sky around the current center position
+p	Compute magnitudes around the cursor position
+f	Fit center, sky and compute magnitudes
+sp	Fit center, sky, compute magnitudes, and save
+q	Exit program
+
+Phot parameters are listed or set with the following commands.
+
+:m [n]	Move cursor to the [nth] object in the coordinate list
+:n [n]	Measure the [nth] object in the coordinate list
+
+:show [center/sky/phot/all]    List the aphot parameters
+:fwhmpsf [value]               Full width half maximum of the PSF
+:noise [string]                Noise model
+:threshold [value]             Threshold value for centering
+:sigma [value]                 Standard deviation of the background
+:ccdread                       CCD readout noise keyword
+:readnoise                     Readout noise in electrons
+:gain                          Gain keyword
+:epadu                         Electrons per adu
+
+:calgorithm [string]           Centering function
+:positive [y/n]                Emission or absorption feature
+:cbox [value]                  Width of the centering box in fwhmpsf
+:cmaxiter [value]              Maximum number of centering iterations
+:maxshift [value]              Maximum shift in fwhmpf
+:minsnratio [value]            Minimum signal to noise ratio of pixels
+:clean [y/n]                   Clean subraster before centering
+:rclip [value]                 Clipping radius in fwhmpsf
+:rclean [value]                Cleaning radius in fwhmpsf
+:kclean [value]                Sigma for clean algorithm
+:mkcenter [y/n]                Mark the centers on the display
+
+:salgorithm [string]           Sky fitting algorithm
+:annulus [value]               Inner radius of sky annulus in fwhmpsf
+:dannulus [value]              Width of sky annulus in fwhmpsf
+:skyvalue [value]              User supplied sky
+:smaxiter [value]              Maximum number of rejection cycles
+:skreject [value]              +/- Pixel rejection limits in sky sigma
+:snreject [value]              Maximum number of rejection interations
+:khist [value]                 +/- Sky histogram size in sky sigma
+:binsize [value]               Resolution of sky histogram in sky sigma
+:smooth [y/n]                  Lucy smooth the sky histogram
+:rgrow [value]                 Region growing radius in fwhmpsf
+:marksky [y/n]                 Mark the sky annuli on the display
+
+:weighting                     Weighting for wphot
+:aperts [string]               Aperture radii in fwhmpsf
+:zmag [value]                  Zero point of magnitude scale
+:exposure [string]             Exposure time keyword
+:itime [value]                 Integration time
+\fR
+.fi
+
+.PP
+We select the interactive setup option, move the image
+cursor to a high signal-to-noise, isolated star and tap the i key.
+PHOT responds by plotting the radial profile of the star on the
+screen and requesting the user to mark the fwhm of
+the psf, the centering aperture, the inner and outer sky annuli,
+the sky background and sigma and the set of circular apertures.
+The parameters so set can be examined and/or reset with the : commands as shown
+above. Sample measurements can be made of several stars by moving the
+cursor and typing the f command. Finally when we are happy with the
+parameter set we type w to store the parameters and q to exit the program.
+.PP
+Now we are ready to do photometry. We enter the PHOT program in batch mode.
+
+.nf
+\f(CW
+	ap> phot blue inter- &
+\fR
+.fi
+
+The batch job is now running, appending output lines to the file "blue.mag.#".
+We can proceed to set up the job for the red image, in much the same way
+that we set up the job for the blue image.  When both jobs finish, we
+can use the list processing tools to filter out the good objects and
+calculate colors.
+
+.NH
+The APPHOT Tasks
+.PP
+Manual pages for the APPHOT tasks are available in the IRAF on line help
+database.
diff --git a/noao/digiphot/apphot/doc/specs/apphot.spc.toc b/noao/digiphot/apphot/doc/specs/apphot.spc.toc
new file mode 100644
index 00000000..757f9a79
--- /dev/null
+++ b/noao/digiphot/apphot/doc/specs/apphot.spc.toc
@@ -0,0 +1,111 @@
+.LP
+.sp
+1.\h'|0.4i'\fBIntroduction\fP\l'|5.6i.'\0\01
+.sp
+2.\h'|0.4i'\fBAPPHOT Package Requirements\fP\l'|5.6i.'\0\01
+.br
+\h'|0.4i'2.1.\h'|0.9i'APPHOT Package Input\l'|5.6i.'\0\01
+.br
+\h'|0.9i'2.1.1.\h'|1.5i'The IRAF Image\l'|5.6i.'\0\01
+.br
+\h'|0.9i'2.1.2.\h'|1.5i'The Coordinate Lists\l'|5.6i.'\0\02
+.br
+\h'|0.9i'2.1.3.\h'|1.5i'Algorithm Parameters\l'|5.6i.'\0\02
+.br
+\h'|0.9i'2.1.4.\h'|1.5i'Terminal Graphics and the Image Display\l'|5.6i.'\0\02
+.br
+\h'|0.4i'2.2.\h'|0.9i'APPHOT Package Functions\l'|5.6i.'\0\03
+.br
+\h'|0.9i'2.2.1.\h'|1.5i'Creating Coordinate Lists\l'|5.6i.'\0\03
+.br
+\h'|0.9i'2.2.2.\h'|1.5i'Coordinate List Operations\l'|5.6i.'\0\03
+.br
+\h'|0.9i'2.2.3.\h'|1.5i'Determining the Image Characteristics\l'|5.6i.'\0\03
+.br
+\h'|0.9i'2.2.4.\h'|1.5i'Centering\l'|5.6i.'\0\03
+.br
+\h'|0.9i'2.2.5.\h'|1.5i'Fitting the Sky\l'|5.6i.'\0\04
+.br
+\h'|0.9i'2.2.6.\h'|1.5i'Multi-aperture Photometry\l'|5.6i.'\0\04
+.br
+\h'|0.9i'2.2.7.\h'|1.5i'Polygonal Aperture Photometry\l'|5.6i.'\0\04
+.sp
+3.\h'|0.4i'\fBAPPHOT Package Specifications\fP\l'|5.6i.'\0\04
+.br
+\h'|0.4i'3.1.\h'|0.9i'Apphot CL Callable Tasks\l'|5.6i.'\0\04
+.br
+\h'|0.4i'3.2.\h'|0.9i'Standard Analysis Procedures\l'|5.6i.'\0\05
+.br
+\h'|0.4i'3.3.\h'|0.9i'The APPHOT Algorithms\l'|5.6i.'\0\05
+.br
+\h'|0.9i'3.3.1.\h'|1.5i'The RADPROF Algorithm\l'|5.6i.'\0\05
+.br
+\h'|0.9i'3.3.2.\h'|1.5i'The FITPSF Algorithm\l'|5.6i.'\0\06
+.br
+\h'|0.9i'3.3.3.\h'|1.5i'The DAOFIND Algorithm\l'|5.6i.'\0\06
+.br
+\h'|0.9i'3.3.4.\h'|1.5i'The CENTER Algorithm\l'|5.6i.'\0\08
+.br
+\h'|1.5i'3.3.4.1.\h'|2.2i'Centering Package Routines\l'|5.6i.'\0\08
+.br
+\h'|1.5i'3.3.4.2.\h'|2.2i'The General Centering Procedure\l'|5.6i.'\0\09
+.br
+\h'|1.5i'3.3.4.3.\h'|2.2i'Symmetry Clean Algorithm\l'|5.6i.'\010
+.br
+\h'|1.5i'3.3.4.4.\h'|2.2i'Signal to Noise Estimate\l'|5.6i.'\010
+.br
+\h'|1.5i'3.3.4.5.\h'|2.2i'Centroid\l'|5.6i.'\010
+.br
+\h'|1.5i'3.3.4.6.\h'|2.2i'Gaussian Fit to the Marginals\l'|5.6i.'\011
+.br
+\h'|1.5i'3.3.4.7.\h'|2.2i'Radial Gaussian Fit to the Subraster\l'|5.6i.'\011
+.br
+\h'|1.5i'3.3.4.8.\h'|2.2i'Optimal Filtering of Marginals\l'|5.6i.'\011
+.br
+\h'|1.5i'3.3.4.9.\h'|2.2i'2D Optimal Filtering\l'|5.6i.'\012
+.br
+\h'|1.5i'3.3.4.10.\h'|2.2i'Other Centering Methods\l'|5.6i.'\012
+.br
+\h'|0.9i'3.3.5.\h'|1.5i'The FITSKY Task\l'|5.6i.'\013
+.br
+\h'|1.5i'3.3.5.1.\h'|2.2i'Sky Fitting Package Routines\l'|5.6i.'\013
+.br
+\h'|1.5i'3.3.5.2.\h'|2.2i'General Sky Fitting Procedures\l'|5.6i.'\014
+.br
+\h'|1.5i'3.3.5.3.\h'|2.2i'Sky Pixel Array Techniques\l'|5.6i.'\014
+.br
+\h'|2.2i'3.3.5.3.1.\h'|2.9i'Mean\l'|5.6i.'\014
+.br
+\h'|2.2i'3.3.5.3.2.\h'|2.9i'Median\l'|5.6i.'\014
+.br
+\h'|2.2i'3.3.5.3.3.\h'|2.9i'Mode\l'|5.6i.'\015
+.br
+\h'|1.5i'3.3.5.4.\h'|2.2i'Histogram Techniques\l'|5.6i.'\015
+.br
+\h'|2.2i'3.3.5.4.1.\h'|2.9i'Centroid\l'|5.6i.'\015
+.br
+\h'|2.2i'3.3.5.4.2.\h'|2.9i'Gaussian Fit\l'|5.6i.'\016
+.br
+\h'|2.2i'3.3.5.4.3.\h'|2.9i'Optimal Filtering\l'|5.6i.'\016
+.br
+\h'|2.2i'3.3.5.4.4.\h'|2.9i'Cross Correlation\l'|5.6i.'\016
+.br
+\h'|1.5i'3.3.5.5.\h'|2.2i'Interactive Techniques\l'|5.6i.'\016
+.br
+\h'|2.2i'3.3.5.5.1.\h'|2.9i'Histogram Plot\l'|5.6i.'\016
+.br
+\h'|2.2i'3.3.5.5.2.\h'|2.9i'Radial Distribution\l'|5.6i.'\016
+.br
+\h'|1.5i'3.3.5.6.\h'|2.2i'Pixel Rejection and Region Growing\l'|5.6i.'\017
+.br
+\h'|0.9i'3.3.6.\h'|1.5i'The APPHOT Task\l'|5.6i.'\017
+.br
+\h'|1.5i'3.3.6.1.\h'|2.2i'The APPHOT Package Routines\l'|5.6i.'\017
+.br
+\h'|1.5i'3.3.6.2.\h'|2.2i'The APPHOT Aperture Integration Algorithm\l'|5.6i.'\018
+.br
+\h'|0.9i'3.3.7.\h'|1.5i'The POLYPHOT Algorithm \l'|5.6i.'\018
+.sp
+4.\h'|0.4i'\fBExample\fP\l'|5.6i.'\019
+.sp
+5.\h'|0.4i'\fBThe APHOT Tasks\fP\l'|5.6i.'\021
diff --git a/noao/digiphot/apphot/doc/ucache.hlp b/noao/digiphot/apphot/doc/ucache.hlp
new file mode 100644
index 00000000..34a091dd
--- /dev/null
+++ b/noao/digiphot/apphot/doc/ucache.hlp
@@ -0,0 +1,15 @@
+If \fIcache\fR is yes and the host machine physical memory and working set size
+are large enough, the input image pixels are cached in memory. If cacheing
+is enabled and the task is run interactively the first measurement will appear
+to take a long time as the entire image must be read in before the measurement
+is actually made. All subsequent measurements will be very fast because the task
+is accessing memory not disk. The point of cacheing is to speed up random
+image access by making the internal image i/o buffers the same size as the
+image itself. However if the input object lists are sorted in row order and
+sparse cacheing may actually worsen not improve the execution time. Also at
+present there is no point in enabling cacheing for images that are less than
+or equal to 524288 bytes, i.e. the size of the test image dev$ypix, as the
+default image i/o buffer is exactly that size. However if the size of dev$ypix
+is doubled by converting it to a real image with the chpixtype task then the
+effect of cacheing in interactive is can be quite noticeable if measurements
+of objects in the top and bottom halfs of the image are alternated.
diff --git a/noao/digiphot/apphot/doc/userdocs/apuser.ms b/noao/digiphot/apphot/doc/userdocs/apuser.ms
new file mode 100644
index 00000000..24492bcc
--- /dev/null
+++ b/noao/digiphot/apphot/doc/userdocs/apuser.ms
@@ -0,0 +1,1881 @@
+.RP
+
+.TL
+A User's Guide to the IRAF Apphot Package
+
+.AU
+Lindsey Elspeth Davis
+.AI
+
+.K2 "" "" "*"
+Revised May 1989
+
+.AB
+.PP
+The APPHOT package is a set of tasks for performing aperture photometry
+on uncrowded or moderately crowded stellar fields in either interactive or batch
+mode. The photometric technique employed is fractional pixel 
+integration. Point spread function fitting techniques are not used and no
+knowledge of the point spread function is required for the computation of
+magnitudes. Separate tasks are provided for creating and modifying object
+lists, computing accurate centers and sky values for a list of objects,
+and performing photometry inside concentric
+circular or polygonal apertures.
+.PP
+This document describes the data preparation required to run APPHOT, how
+to set up the display and graphics devices, how to set the algorithm
+parameters, how to run the package tasks in interactive or batch mode
+and how to selectively examine the results. Detailed descriptions of the
+algorithms can be found in the document \fISpecifications for the
+APPHOT Package\fR by the author.
+.PP
+This document applies to APPHOT under IRAF version 2.8.  APPHOT
+can be run under IRAF versions 2.5, 2.6 and 2.7  with only minor changes in
+the task setup. These differences are documented
+where appropriate in the text.
+.AE
+
+.NH
+Introduction
+.PP
+The APPHOT package is a set of tasks for performing
+aperture photometry on uncrowded or moderately crowded fields.
+The photometric technique employed is fractional pixel integration. Point
+spread function techniques are not used and no knowledge of the point spread
+function is required for the computation of magnitudes.
+.PP
+The APPHOT package performs multi-aperture photometry on digitized starfields
+maintained as IRAF image files. Input to the package consists of an
+image file(s), an optional list(s) of object coordinates,
+numerous parameters controlling
+the analysis algorithms and, optionally, the graphics terminal and/or
+display. APPHOT output consists of successive records, where each record
+records the results of the analysis for a single object. Some tasks 
+also produce graphics output in the form of plot metacode files.
+.PP
+Given starting coordinates and an IRAF image, the principal APPHOT
+task \fBphot\fR computes accurate centers, sky values and magnitudes
+for a list of objects.  Separate
+IRAF callable tasks in APPHOT exist to create and modify object
+lists, to determine image characteristics such as the full width half maximum
+of the point spread function or standard deviation of the sky pixels,
+to compute accurate centers for a list of objects, to compute accurate local sky
+values for a list of objects, and to compute magnitudes inside a polygonal
+aperture.
+.PP
+The image data requirements of the APPHOT package are described in section 2.
+Section 3 describes various ways to tailor the IRAF environment to run
+the APPHOT package. Section 4 describes how to load the APPHOT tasks and how
+use the on-help facility.  Section 5 describes how to examine and edit the
+APPHOT task and algorithm parameters. Several methods of creating and
+modifying APPHOT coordinate lists files are described in section 6.
+Sections 7 and 8 describe how to run the APPHOT tasks interactively without
+and with a coordinate list respectively. Batch mode reductions in APPHOT are
+described in section 9.  Section 10 describes the format of the APPHOT output
+catalogue and plot files. Section 12 lists various APPHOT recipes for reducing
+common types of astronomical data with APPHOT.
+
+.NH
+Data Preparation and Requirements
+.PP
+APPHOT assumes that the images to be analyzed exist on disk in IRAF readable
+format.  Facilities for reading and writing images exist elsewhere in IRAF
+in the DATAIO and MTLOCAL packages. None of the current APPHOT
+tasks alter the disk input images in any way.
+.PP
+APPHOT assumes that the pixel data is linear. The input images should be
+corrected for those instrumental defects which affect the intensity
+of a pixel prior to entering the APPHOT package. These defects include pixel
+to pixel variations in the bias values,
+pixel to pixel gain variations, cosmic rays, cosmetic defects, geometric
+distortion and detector non-linearities. Users should be aware of the IRAF
+CCDRED package for reducing CCD data and the DTOI package for converting
+photographic density data to intensity data.
+.PP
+Extreme valued pixels should be removed from the images prior to entering
+the APPHOT package. These include pixel values at or near the data limits of the
+host machine as well as any host machine values such as INDEF,
+produced by divide by zero, and floating point underflows and overflows.
+Floating point operations involving such numbers may crash
+with arithmetic exception errors. For efficiency and portability reasons
+the APPHOT package and most IRAF routines do not test for these numbers.
+The \fBimreplace\fR and \fBimedit\fP tasks in the PROTO  package can be used to replace extreme
+valued pixels.  More general system facilities for handling bad pixels
+inside IRAF are planned for the near future.
+.PP
+In order to normalize the magnitude scales of a list of images to a common
+integration time,
+APPHOT requires that the image exposure times be stored in the image header.
+Similarly the correct computation of magnitude errors requires that
+the readout noise and gain parameters also be present in the image
+header or be supplied as constants in the APPHOT parameter files.
+The readout noise must be supplied in units of electrons and the gain
+is assumed to be in electrons per adu. The time units are arbitrary
+but must be consistent for a given set of images.
+APPHOT tasks access this information using a keyword and value scheme.
+The IMAGES package task \fBhedit\fR can be used to insert or edit this
+information prior to entering the APPHOT package. For example the following
+commands will enter the gain, readout noise and exposure time information
+into the headers of a list of images.
+
+.nf
+	\f(CWcl> hedit *.imh gain 14.0 add+ ver-
+	cl> hedit *.imh readout 20.0 add+ ver-
+	cl> hedit *.imh exptime add+ ver+\fR
+.fi
+
+.PP
+The point spread function is assumed to be constant for all regions
+of the image. This is critical in the case of faint objects for
+which small apertures which minimize the effects of crowding and sky noise in
+the aperture are used. The wings of the object will almost certainly extend
+beyond the aperture and good results will only be obtained if objects
+are consistently well centered and the shape and diameter of an object is
+constant throughout the object and invariant to magnitude.
+.PP
+The centering routines built into the APPHOT package  assume that
+the images are close to circularly symmetric over the region to be used
+in centering although small deviations do not
+significantly affect the accuracy of the results.
+The user should be aware of the more sophisticated 
+but less efficient centering routines in the \fBdaofind\fR and \fBfitpsf\fR
+routines. Several choices of centering algorithm are available in
+APPHOT including  no centering.
+.PP
+APPHOT assumes that the local sky background is approximately flat in the
+vicinity of the object being measured. This assumption is equivalent to
+assuming that
+the local sky region has a unique mode. Therefore any variations in the
+sky background which occur at the same scale as the sky region should be
+removed prior to entering the APPHOT package.
+
+.NH
+Setting up the IRAF Environment for APPHOT
+.NH 2
+Script, Compiled and Pset Tasks
+.PP
+IRAF supports three types of tasks: scripts, compiled tasks and pset tasks.
+In order to distinguish one type of task from another, APPHOT users should 
+set the cl parameter \fBshowtype\fR to yes as shown below.
+
+.nf
+	\f(CWcl> cl.showtype=yes\fR
+.fi
+
+The cl command \fB?\fR or \fB?\fR \fIpackage\fR identifies script
+tasks by a terminating period and pset tasks by a terminating @.
+No trailing characters are added to the compiled task names. Pset tasks are
+important to the APPHOT package and will be discussed further in
+section 5.
+
+.NH 2
+Other IRAF Packages
+.PP
+Before running APPHOT, users may wish to load the IRAF packages, DATAIO,
+IMAGES, 
+TV and PLOT. Various input and output routines exist in the DATAIO package,
+including the fits reader and writer and the cardimage reader and
+writer. The IMAGES package contains routines for basic image arithmetic,
+for computing image statistics, for listing individual pixel values,
+and for examining and
+modifying the image headers. TV, a subpackage of IMAGES, contains the
+\fBdisplay\fR task for loading images into the display device.
+The PLOT package contains tasks for plotting
+image data and for extracting and displaying individual plots from the plot
+metacode files produced by the APPHOT tasks.
+.PP
+Various useful tasks for manipulating and displaying the data produced by
+APPHOT can be found in the PROTO package under the NOAO package. In
+particular the user should be aware of the \fBfields\fR, \fBmkhistogram\fR
+and \fBtvmark\fP tasks.
+
+.NH 2
+The Image Cursor and Display Device
+.PP
+The APPHOT tasks are designed in interactive mode to read the image cursor
+and to perform various actions based on the position of the image cursor
+and the keystroke typed. The image cursor is directed to the display
+device defined by the environment variable \fBstdimage\fR. To check the
+value of the default display device, type the following command.
+
+.nf
+	\f(CWcl> show stdimage
+	imt512\fR
+.fi
+
+In this example the default display device is the 512 pixel square SUN
+imtool window.
+All tasks which write images to the display access this
+device. For example the
+TV package \fBdisplay\fR program will load an image onto this device.
+.PP
+In normal operation IRAF tasks which read the image cursor would read
+the hardware cursor from this device.
+In response to the user command
+
+.nf
+	\f(CWcl> =imcur
+	or
+	cl> show imcur\fR
+.fi
+
+the cursor would come up on the image display ready to accept a
+keystroke command.  At this point the user should check that the display
+is reading the correct image coordinates by moving the image cursor to
+the lower left hand corner of the display image and tapping any key.
+The coordinates should read x,y = (1,1) if the whole image was
+displayed.
+.PP
+Cursor readback is currently implemented under IRAF version 2.7 for the
+SUN workstations and the IIS model 70. Users with older versions of IRAF
+or other devices cannot run APPHOT tasks directly from the image display
+device and must redirect the image cursor.
+Two choices are available.
+.IP [1]
+The image cursor can be directed to accept commands from
+the standard input. This is the default setup under IRAF version 2.6.
+This setup can be checked by typing the following command.
+
+.nf
+	\f(CWcl> show stdimcur
+	text\fR
+.fi
+
+If the value of \fBstdimcur\fR is not "text" the user can set this value by
+typing the following.
+
+.nf
+	\f(CWcl> set stdimcur = text\fR
+.fi
+
+Each time the cursor is to be read the user will be prompted for image
+cursor mode text input. The form and syntax of this command are
+described in detail in section 7.3.
+.IP [2]
+Alternatively a contour plot of the image can be used in place of the
+image display and APPHOT tasks can be directed to read the graphics cursor.
+To direct the image cursor to the graphics device the user types
+
+.nf
+	\f(CWcl> set stdimcur = stdgraph\fR
+.fi
+
+This usage permits interactive use of the APPHOT package for users with graphics
+terminals but no image display. This setup is most suitable for terminals
+which permit the text and graphics planes to be displayed simultaneously.
+.RS
+.LP
+It is currently the responsibility of the user to ensure that the image
+displayed on the image display is the same as the image operated on by
+the APPHOT tasks.
+.RE
+
+.NH
+Loading the Apphot Package
+.PP
+At this point the user has the local environment set up and is ready to
+load the APPHOT package.  APPHOT resides in the DIGIPHOT package (IRAF
+version 2.8 and later) under the NOAO suite of packages.
+Assuming
+that the NOAO package is already loaded the user types the following.
+
+.nf
+	\f(CWcl> digiphot
+	cl> apphot\fR
+.fi
+
+APPHOT can also be an add-on package (IRAF version 2.7 and earlier) 
+installed under the
+LOCAL package. In this case the user types.
+
+.nf
+	\f(CWcl> local
+	cl> apphot\fR
+.fi
+
+The following menu of tasks is displayed.
+
+.nf
+\f(CW
+  apselect      daofind     fitsky        photpars@   polyphot   wphot
+  center        datapars@   fitskypars@   polymark    qphot    
+  centerpars@   fitpsf      phot          polypars@   radprof
+\fR
+.fi
+
+The APPHOT package is now loaded and ready to run.
+A quick one line description of each APPHOT task can be obtained by typing
+the following command.
+
+.nf
+	\f(CWap> help apphot\fR
+.fi
+
+The following text appears.
+.KS
+.nf
+\f(CW
+digiphot.apphot:
+       apselect - Extract select fields from apphot output files
+         center - Compute accurate centers for a list of objects
+     centerpars - Edit the centering parameters
+        daofind - Find stars in an image using the DAO algorithm
+       datapars - Edit the data dependent parameters
+         fitpsf - Model the stellar psf with an analytic function
+         fitsky - Compute sky values in a list of annular or circular
+                  regions
+     fitskypars - Edit the sky fitting parameters
+           phot - Measure magnitudes for a list of stars
+       photpars - Edit the photometry parameters
+       polymark - Create polygon and coordinate lists for polyphot
+       polyphot - Measure magnitudes inside a list of polygonal regions
+       polypars - Edit the polyphot parameters
+          qphot - Measure quick magnitudes for a list of stars
+        radprof - Compute the stellar radial profile of a list of stars
+          wphot - Measure magnitudes with weighting
+\fR
+.fi
+.KE
+For the remainder of this document
+we will use the principal APPHOT task \fBphot\fR as an example of how to
+setup the parameters in both interactive and batch mode.
+To get detailed help  on the phot task the user types the following.
+
+.nf
+	\f(CWcl> help phot | lprint\fR
+.fi
+
+The help page(s) for the \fBphot\fR task will appear on the local default
+printer.
+
+.NH
+Setting the APPHOT Photometry Task Parameters
+.PP
+The principal APPHOT task PHOT is described in sections 5.1 to 5.6.  The
+quick photometry task QPHOT is described in section 5.7 and the
+polygonal aperture photometry task POLYPHOT is described in section
+5.8.
+.NH 2
+The Task Parameters
+.PP
+The \fBphot\fR task parameter set specifies the required image, coordinate
+and output files, the graphics and display devices, the graphics and image
+cursor and the mode of use of the task, interactive or batch. To enter
+and edit the parameter set for the \fBphot\fR task the user types the
+following.
+
+.nf
+	\f(CWcl> epar phot\fR
+.fi
+
+The parameter set for the \fBphot\fR task will appear on the terminal ready
+for editing as follows.
+
+.nf
+\f(CW
+                             IRAF
+             Image Reduction and Analysis Facility
+
+   PACKAGE = apphot
+   TASK = phot
+   
+   image   =                       Input image
+   (datapar=                     ) Data dependent parameters
+   (centerp=                     ) Centering parameters
+   (fitskyp=                     ) Sky fitting parameters
+   (photpar=                     ) Photometry parameters
+   (coords =                     ) Coordinate list
+   skyfile =                       Sky file
+   (output =              default) Results file
+   (plotfil=                     ) File of plot metacode
+   (graphic=             stdgraph) Graphics device
+   (display=             stdimage) Display device
+   (command=                     ) Image cursor: [x y wcs] key [cmd]
+   (cursor =                     ) Graphics cursor: [x y wcs] key [cmd]
+   (radplot=                   no) Plot the radial profiles
+   (interac=                  yes) Mode of use
+   (verify =                  yes) Verify critical parameters in non
+                                   interactive mode
+   (verbose=                   no) Print messages in non interactive mode
+   (mode   =                   ql)
+\fR
+.fi
+
+The \fBphot\fR parameters can be edited in the usual fashion by successively
+moving
+the cursor to the line opposite the parameter name, entering the new value,
+followed by a carriage return, and finally typing a ^Z to exit the
+\fBepar\fR task and update the parameters.
+Some general points about the task
+parameter sets are summarized below. For more detailed descriptions of each
+parameter see the help pages for each task.
+.IP [1]
+\fBImage\fR specifies the list of input image(s) containing the 
+stars to be measured. \fBImage\fR may be a list of images, an image
+template or a file containing a list of images.
+For example if we wish to measure stars in three images: m31U, m31B and
+m31V we could specify the \fBimage\fR parameter in the following three ways.
+
+.nf
+\f(CW
+   image   =       m31B,m31U,m31V  Input image
+	or
+   image   =             m31*.imh  Input image
+	or
+   image   =              @imlist  Input image
+\fR
+.fi
+
+"Imlist" is the name of a text file containing the list of images
+one image name per line. The image list file can easily be created with the cl
+package \fBfiles\fR task or the editor.
+.IP [2]
+Four parameter sets, henceforth psets, \fBdatapars\fR, \fBcenterpars\fR,
+\fBfitskypars\fR and \fBphotpars\fR specify the algorithm parameters.
+They are described in detail in later sections. 
+.IP [3]
+\fBCoords\fR specifies the name of the coordinate file(s) containing the
+initial positions of the stars to be measured. If \fBcoords\fR = "",
+the current image cursor position is read and used as the initial position.
+The number of files specified by
+\fBcoords\fR must be either one, in  which
+case the same coordinate file is used for all the images, or equal in
+number to the set of input images.
+\fBCoords\fR can be a list of files, a file name template,
+or a file
+containing the list of x and y coordinates one per line.
+For example if we have three coordinate files "m31B.coo", "m31U.coo" and
+"m31V.coo" for the three images listed above, we could set the \fBcoords\fR
+parameter in the following three ways.
+
+.nf
+\f(CW
+   (coords = m31B.coo,m31U.coo,m31V.coo) Coordinate list
+	or
+   (coords =             m31*.coo) Coordinate list
+	or
+   (coords =           @coordlist) Coordinate list
+\fR
+.fi
+
+"Coordlist" is the name of a text file containing the names of the coordinate
+files in the desired order one per line.
+.IP [4]
+\fBOutput\fR specifies the name of the results file(s). If \fBoutput\fR =
+"default" then a single output file is created for
+each input image and the root of the output file name is the name of the
+input image. In the case of the above example \fBphot\fR would create three
+output files called "m31B.mag.1", "m31U.mag.1" and "m31V.mag.1" assuming
+that this was the initial run of \fBphot\fR on these images.
+If the user sets the \fBoutput\fR parameter then the number of output files
+must be either one or equal to the number of input images. For example the
+user could set \fBoutput\fR to either
+
+.nf
+\f(CW
+   (output =              m31.out) Results
+   or
+   (output = m31b.out,m31u.out,m31v.out) Results
+\fR
+.fi
+
+If the user sets \fBoutput\fR = "" then no output file is written.
+.IP [5]
+The parameters \fBgraphics\fR and \fBdisplay\fR specify the graphics and
+image display devices. In IRAF version 2.6 and later the APPHOT tasks
+which reference these parameters will in interactive mode issue a warning
+if they cannot open either of these devices
+and continue execution. In IRAF version 2.5 the \fBdisplay\fR parameter must
+be set to "stdgraph" as listed below
+
+.nf
+\f(CW
+   (display=             stdgraph) Display device
+\fR
+.fi
+
+or the following system error will be generated.
+
+.nf
+\f(CW
+    "cannot execute connected subprocess x_stdimage.e"
+\fR
+.fi
+Most of the APPHOT tasks use IRAF graphics in interactive mode to allow
+users to set up their parameters and /or examine their results using radial
+profile plots. The \fBgraphics\fR specifies which graphics device these plots
+will be written to. Similarly most IRAF tasks permit the user to optionally
+mark the star positions, apertures and sky annuli on the display device.
+The parameter \fBdisplay\fR specifies which image display device this
+information will be written to. Currently IRAF does not support an image display
+kernel so the display marking features of APPHOT are not available unless
+the user chooses to run APPHOT interactively from a contour plot.
+.IP [6]
+If \fBplotfile\fR is not equal to "", then for each star written to
+\fBoutput\fR
+a radial profile plot is written to the plot metacode file \fBplotfile\fR.
+The \fBplotfile\fR is opened in append mode and succeeding executions
+of \fBphot\fR write to the end of the same file which may in the process
+become very large.
+\fIThe user should be aware that writing radial profile plots
+to \fBplotfile\fI can significantly slow the execution of \fBphot\fR.
+The variable \fBradplots\fR enables radial profile plotting in interactive mode.
+For each star measured a radial profile plot displaying the answers is
+plotted on the screen.
+.IP [7]
+The \fBinteractive\fR parameter switches the task between interactive
+and batch mode.
+In interactive mode plots and text are written to the terminal as well as the
+output file and the user can show and set the parameters. In batch mode
+\fBphot\fR executes silently.
+.IP [8]
+The \fBverify\fP parameter allows the user to verify the critical task
+parameters in non interactive mode.  It is normally set to yes but
+should be turned off when submitting jobs to background.
+.IP [9]
+The \fBverbose\fP switch permits the printing of results to the standard
+output in non interactive mode.  It is normally turned off.
+
+.NH 2
+APPHOT Psets
+.PP
+APPHOT algorithm parameters have been gathered together into logical
+groups and stored in parameter files. The use of psets permits the
+user to store APPHOT parameters with their relevant datasets rather than
+in the uparm directory and allows APPHOT tasks to share common parameter
+sets. APPHOT presently supports 5 pset files: 1) \fBdatapars\fR which contains
+the data dependent parameter 2) \fBcenterpars\fR which contains the
+centering algorithm parameters 3) \fBfitskypars\fR which contains the
+sky fitting
+algorithm parameters 4) \fBphotpars\fR which contains the multiaperture
+photometry parameters and 5) \fBpolypars\fR which contains the polygonal
+aperture
+photometry parameters. The user should consult the manual page for each
+of the named pset files as well as the attached parameter set document,
+\fIExternal Parameter Sets in the CL and Related Revisions\fR, by Doug Tody.
+.PP
+The default mode of running APPHOT is to edit and store the pset parameter
+files in the uparm directory.  For example to edit the
+\fBdatapars\fR parameter set, the user types either
+
+.nf
+	\f(CWcl> epar datapars\fR
+	or
+	\f(CWcl> datapars\fR
+.fi
+
+and edits the file as usual. All the top level tasks which reference this
+pset will pick up the changes from the uparm directory, assuming
+datapars = "".
+.PP
+Alternatively the user can edit the \fBphot\fR
+task and its psets all at once as follows using \fBepar\fR.
+
+.nf
+	\f(CWcl> epar phot\fR
+.fi
+
+Move the cursor to the \fBdatapars\fR parameter line and type \fB:e\fR.
+The menu for the 
+\fBdatapars\fR pset will appear and is ready for editing. Edit the desired
+parameters and type \fB:q\fR. \fBEpar\fR will return to the main
+\fBphot\fR parameter set.
+Follow the same procedure for the other three psets
+\fBcenterpars\fR, \fBfitskypars\fR and \fBphotpars\fR and exit the program
+in the usual manner.
+.PP
+Sometimes it is desirable to store a given pset along with the data.
+This provides a facility for keeping many different copies of say the
+\fBdatapars\fR pset with the data.
+The example below shows how to write a pset out to a file in the same directory
+as the data. The user types
+
+.nf
+	\f(CWcl> epar phot\fR
+.fi
+
+as before, enters the datapars menu with \f(CW:e\fR and edits the parameters.
+The command
+
+.nf
+	\f(CW:w data1.par\fR
+.fi
+
+writes the parameter set to a file called "data1.par" and a \fB:q\fR
+returns to the main task menu.
+A file called "data1.par" containing the new \fBdatapars\fR parameters
+will be written in the current directory. At this point the user is in the
+\fBphot\fR parameter set at the line opposite \fBdatapars\fR and
+enters "data1.par" on the line opposite this parameter.
+The next time \fBphot\fR is run the parameters will
+be read from "data1.par" not from the pset in the uparm directory.
+This procedure can be repeated for each data set which has distinct parameters,
+as in for example data taken on separate nights.
+
+.NH 2
+Datapars
+.PP
+All the data dependent parameters have been gathered together in one
+pset \fBdatapars\fR. The idea behind this organization is to facilitate
+setting up the algorithm
+psets for data taken under different conditions. For example the
+user may have determined the optimal centering box size, sky annulus radius
+and width and aperture radii in terms of the current \fBfwhmpsf\fR and the
+rejection criteria in terms of the current background standard deviation
+\fBsigma\fR.  In order to use the same setup on
+the next image the user need only reset the \fBscale\fR and background
+\fBsigma\fR parameters to the new values.
+The only pset which need be edited is \fBdatapars\fR.
+.PP
+To examine and edit the \fBdatapars\fR pset type
+
+.nf
+	\f(CWap> datapars\fR
+.fi
+
+and the following menu will appear on the screen.
+
+.nf
+\f(CW
+                                IRAF
+                  Image Reduction and Analysis Facility
+
+   PACKAGE = apphot
+   TASK = datapars
+
+   (fwhmpsf=                   1.) FWHM of the PSF in scale units
+   (emissio=                  yes) Features are positive
+   (noise  =              poisson) Noise model
+   (thresho=                   0.) Detection threshold in counts above
+                                   background
+   (cthresh=                   0.) Centering threshold in counts above
+                                   background
+   (sigma  =                INDEF) Standard deviation of background in counts 
+   (scale  =                   1.) Image scale in units per pixel
+   (ccdread=                     ) CCD readout noise image header keyword
+   (readnoi=                INDEF) CCD readout noise in electrons
+   (gain   =                     ) CCD gain image header keyword
+   (epadu  =                   1.) Gain in electrons per count
+   (exposur=                     ) Exposure time image header keyword
+   (itime  =                INDEF) Integration time
+   (datamin=                INDEF) Minimum good data pixel
+   (datamax=                INDEF) Maximum good data pixel
+   (mode   =                   ql)
+   ($nargs =                    0)
+\fR
+.fi
+
+.PP
+The following is a brief description of the parameters and their function
+as well as some initial setup recommendations.
+
+.PP
+\fBScale\fP is the image scale parameter in units per pixel, for example
+arc-seconds per pixel.  All distance dependent parameters in the APPHOT package
+including the centering box width \fBcbox\fP in \fBcenterpars\fP, the 
+inner radius and width of the sky annulus, \fBannulus\fP and 
+\fBdannulus\fP in \fBfitskypars\fP, and the radii of the concentric
+circular apertures \fBapertures\fP in \fBphotpars\fP are defined
+in scale units, for example arc seconds.  This permits easy comparison
+with apertures published in the literature.  Some other algorithm
+parameters such as \fBmaxshift\fP in \fBcenterpars\fP and the region
+growing radius \fBrgrow\fP in
+\fBfitskypars\fP are also defined in scale units.  By default all
+distance parameters are defined in pixels.
+.PP
+\fBFwhmpsf\fP is used as a first guess for modelling the psf in the 
+\fBfitpsf\fP task, is important for the optimal use of the \fBdaofind\fP
+algorithm, and critical for the centering algorithms "gauss" and
+"ofilter" as well as the \fBwphot\fP task.
+\fBFwhmpsf\fR as well as the other distance dependent parameters
+can be set interactively from inside most of the APPHOT tasks.
+.PP
+\fBFwhmpsf\fP and \fBscale\fP can be combined in an interesting way.
+\fBScale\fP can be defined in units of half width half maximum of the psf per
+pixel in which case the value of \fBfwhmpsf\fP should be set to
+\fB2.0\fP by definition.  By trial and error and use of the interactive
+setup menu optimal values of the remaining distance dependent parameters
+can be determined in units of \fBscale\fP.  Once determined the same
+setup can be reused on another image by simply reseting the \fBscale\fP
+parameter.
+.PP
+APPHOT photometry routines permit measurement of both emission and absorption
+features.  For the majority of applications including photometry of
+stars and galaxies
+all "objects" are emission "objects" and the \fBemission\fR parameter should
+be left at yes.
+.PP
+APPHOT currently supports two noise models "constant" and "poisson".
+If \fBnoise\fR = "constant" the magnitude errors are computed from the
+Poisson noise in the sky background plus the readout noise.
+If \fBnoise\fR = "poisson"
+the magnitude errors are computed on the basis of the Poisson noise in the
+constant sky background, Poisson noise in the object and readout noise.
+Most users
+with CCD data will wish to leave \fBnoise\fR = "poisson".
+\fBCthreshold\fR is a parameter required by the centering algorithms.
+If \fBcthreshold\fR > 0.0, pixels below the data minimum plus
+threshold in the centering subraster are not used by the centering algorithm.
+For difficult centering problems the user may wish to adjust
+this parameter.
+The \fBsigma\fR parameter specifies the standard deviation of the background
+in a single pixel. \fBSigma\fR is used
+to estimate the signal to noise ratio in the centering subraster and to set
+the width and bin size of the histogram of sky pixels, the \fBkhist\fR and
+\fBbinsize\fR parameters in the pset \fBfitskypars\fR. Both \fBcthreshold\fR and
+\fBsigma\fR can be set interactively from inside the \fBphot\fR task.
+.PP
+APPHOT currently recognizes three image header keywords \fBccdread\fR,
+\fBgain\fR and \fBexposure\fR.  Knowledge of the instrument gain and
+readout noise is required for the correct computation of the magnitude
+errors but not required for the magnitude computation. The units of
+the gain and readout noise are assumed to be electrons per adu
+and electrons respectively.
+Exposure time information is required to normalize the magnitudes computed
+for a series of images to a common exposure time.
+The time units are arbitrary but must be consistent for a set of images.
+If this information is already in the
+image header the user can enter the appropriate header keywords.
+Otherwise the instrument constants gain and readout noise can be entered
+into the parameters \fBepadu\fR and \fBreadnoise\fR.
+If the exposure time information is not present in the image header, the
+user can either edit it in with the \fBhedit\fR task or change the \fBitime\fR
+parameter for each image reduced. If both image header keywords and
+default parameter values are defined the image header keywords take
+precedence.
+.PP
+The two parameters \fBdatamin\fP and \fBdatamax\fP which define the upper
+and lower good data limits respectively are not currently implemented by
+the APPHOT tasks.  They will be used in future versions of the package 
+to, for example, set the limits over which a detector is linear.
+.PP
+After editing, the new \fBdatapars\fR pset might look like the following.
+This user has chosen to wait and set \fBfwhmpsf\fR, \fBthreshold\fR,
+\fBcthreshold\fR, and \fBsigma\fR interactively from inside \fBphot\fR but
+has decided to set the
+image header parameters \fBccdread\fR, \fBgain\fR and \fBexposure\fR.
+
+.nf
+\f(CW
+                           IRAF
+             Image Reduction and Analysis Facility
+
+   PACKAGE = apphot
+   TASK = datapars
+   
+   (fwhmpsf=                   1.) FWHM of the PSF in scale units
+   (emissio=                  yes) Features are positive
+   (noise  =              poisson) Noise model
+   (thresho=                   0.) Detection threshold in counts above 
+                                   background
+   (cthresh=                   0.) Centering threshold in counts above
+                                   background
+   (sigma  =                INDEF) Standard deviation of background in counts
+   (scale  =                   1.) Image scale in units per pixel
+   (ccdread=              readout) CCD readout noise image header keyword
+   (readnoi=                INDEF) CCD readout noise in electrons
+   (gain   =                 gain) CCD gain image header keyword
+   (epadu  =                   1.) Gain in electrons per count
+   (exposur=              exptime) Exposure time image header keyword
+   (itime  =                INDEF) Integration time
+   (datamin=                INDEF) Minimum good data pixel
+   (datamax=                INDEF) Maximum good data pixel
+   (mode   =                   ql)
+   ($nargs =                    0)
+\fR
+.fi
+
+.NH 2
+The Centering Parameters
+.PP
+The centering algorithm parameters have been grouped together in a single
+parameter set \fBcenterpars\fR. To display and edit these parameters type
+the command.
+
+.nf
+	\f(CWap> centerpars\fR
+.fi
+
+The following menu will appear on the terminal.
+
+.nf
+\f(CW
+                              IRAF
+               Image Reduction and Analysis Facility
+
+   PACKAGE = apphot
+   TASK = centerpars
+   
+   (calgori=             centroid) Centering algorithm
+   (cbox   =                   5.) Centering box width in scale units 
+   (maxshif=                   1.) Maximum center shift in scale units
+   (minsnra=                   1.) Minimum SNR ratio for centering
+   (cmaxite=                   10) Maximum iterations for centering algorithm
+   (clean  =                   no) Symmetry clean before centering
+   (rclean =                   1.) Cleaning radius in scale units
+   (rclip  =                   2.) Clipping radius in scale units
+   (kclean =                   3.) K-sigma rejection criterion in skysigma
+   (mkcente=                   no) Mark the computed center
+   (mode   =                   ql)
+   ($nargs =                    0)
+\fR   
+.fi
+
+.PP
+APPHOT offers three choices for the  centering algorithm:
+the default "centroid", "gauss" and "ofilter".
+The default centering algorithm does not depend on \fBfwhmpsf\fR but the
+remaining two do. For reasons of simplicity and efficiency the author
+recommends the default algorithm. In cases where there is significant
+crowding or the data is very noisy users may wish to experiment with
+the other algorithms. Centering can be disabled by setting
+\fBcalgorithm\fR = "none". This option is useful if accurate centers
+have already been computed with the \fBdaofind\fR or \fBfitpsf\fR
+tasks. More detailed information on the APPHOT centering algorithms
+can be found in the document,  \fISpecifications for the Apphot Package\fR
+by Lindsey Davis.
+.PP
+The centering box \fBcbox\fR is defined in units of \fBscale\fR.
+Users  should try to set \fBcbox\fR as small as possible to avoid
+adding noisy pixels to the centering subraster.
+\fBCbox\fR can also be set interactively from inside the APPHOT \fBphot\fR
+task.
+.PP
+If the computed centers are more than \fBmaxshift\fR / \fBscale\fR pixels
+from the initial centers or the signal-to-noise ratio in the centering
+subraster is less than \fBminsnratio\fR the new center will be computed but
+flagged with a warning message.
+.PP
+For stars which are crowded or contaminated by bad pixels the user may
+wish to enable the cleaning algorithm by setting \fBclean\fR = yes.
+Its use is complicated and not recommended for most data.  The algorithm is
+described in the APPHOT specifications document.
+.PP
+If \fBmkcenter\fR=yes,  \fBphot\fR tasks will mark the initial
+and final centers and draw a line between them on the default display
+device. At present this option only works if \fBdisplay\fR="stdgraph".
+.PP
+In the above example we have elected to leave the \fBcalgorithm\fR parameter
+at its default value and set \fBcbox\fR interactively from inside the \fBphot\fR
+task.
+
+
+.NH 2
+The Sky Fitting Parameters
+.PP
+The sky fitting algorithm parameters have been grouped together in a single
+parameter set \fBfitskypars\fR. To display and edit these parameters type
+the following command.
+
+.nf
+	\f(CWap> fitskypars\fR
+.fi
+
+The following menu will appear on the terminal.
+
+.nf
+\f(CW
+                              IRAF
+               Image Reduction and Analysis Facility
+
+   PACKAGE = apphot
+   TASK = fitskypars
+   
+   (salgori=                 mode) Sky fitting algorithm
+   (annulus=                  10.) Inner radius of sky annulus in scale units
+   (dannulu=                  10.) Width of sky annulus in scale units
+   (skyvalu=                   0.) User sky value
+   (smaxite=                   10) Maximum number of sky fitting iterations
+   (snrejec=                   50) Maximum number of sky fitting rejection
+                                   iterations
+   (skrejec=                   3.) K-sigma rejection limit in sky sigma
+   (khist  =                   3.) Half width of histogram in sky sigma
+   (binsize=                  0.1) Binsize of histogram in sky sigma
+   (smooth =                   no) Lucy smooth the histogram
+   (rgrow  =                   0.) Region growing radius in scale units
+   (mksky  =                   no) Mark sky annuli on the display
+   (mode   =                   ql)
+   ($nargs =                    0)
+\fR
+.fi
+
+.PP
+APPHOT offers ten sky fitting algorithms. The algorithms can be grouped
+into 4 categories 1) user supplied sky values including "constant" and "file"
+2) sky pixel distribution algorithms including "median" and "mode",
+3) sky pixel histogram algorithms including "centroid", "crosscor",
+"gauss" and "ofilter" 4) interactive algorithms including "radplot"
+and "histplot".
+The definitions of the mode used by APPHOT is the following.
+
+.nf
+\f(CW	mode = 3.0 * median - 2.0 * mean\fP
+.fi
+
+Detailed descriptions of the algorithms can be found in the document,
+\fISpecifications for the Apphot Package\fR by the author. The author recommends
+"mode" the default, and one of the two histogram algorithms "centroid" and
+"crosscor".
+.PP
+The inner radius and width of the sky annulus in terms of \fBscale\fR
+are set by the parameters \fBannulus\fR and \fBdannulus\fR. These can
+easily be set interactively from within the \fBphot\fR task.
+Good statistics require several hundred sky pixels.
+The user should be aware that a circular sky region can be defined by
+setting \fBannulus\fR to 0.
+.PP
+The user should ensure that the parameter \fBsigma\fR in the
+\fBdatapars\fR parameter set is defined if one of the histogram dependent
+sky fitting algorithms is selected.
+The extent and resolution of the sky pixel histogram is determined
+by \fBkhist\fR and \fBbinsize\fR and their relation to \fBsigma\fR.
+If \fBsigma\fR is undefined then the standard deviation of the local
+sky background is used to parameterise \fBkhist\fR and \fBbinsize\fR
+and the histograms of different stars can deviate widely in resolution.
+.PP
+The sky rejection algorithms are controlled by the parameters \fBskreject\fR,
+\fBsnreject\fR and \fBrgrow\fR. It is strongly recommended that the user
+leave pixel rejection enabled. The user should experiment with the region
+growing radius if the local sky regions are severely crowded.
+.PP
+If \fBmksky\fR = yes, \fBphot\fR will mark the inner
+and outer sky annuli. At present this option
+will only work if \fBdisplay\fR = "stdgraph".
+
+.NH 2
+The Photometry Parameters
+.PP
+The photometry algorithm parameters have been grouped together in a single
+parameter set \fBphotpars\fR. To display and edit these parameters type.
+
+.nf
+	\f(CWap> photpars\fR
+.fi
+
+The following menu will appear on the terminal.
+
+.nf
+\f(CW
+                              IRAF
+               Image Reduction and Analysis Facility
+
+   PACKAGE = apphot
+   TASK = photpars
+   
+   (weighti=             constant) Photometric weighting scheme for wphot
+   (apertur=                   3.) List of aperture radii in scale units
+   (zmag   =                  26.) Zero point of magnitude scale
+   (mkapert=                   no) Draw apertures on the display
+   (mode   =                   ql)
+   ($nargs =                    0)
+\fR
+.fi
+
+.PP
+There are three weighting options inside APPHOT. The default is "constant".
+Inside the \fBphot\fR, \fBradprof\fR and \fBpolyphot\fR tasks only constant
+weighting is used. Two other weighting schemes are available for the
+experimental \fBwphot\fR task, "gauss" and "cone". "Gauss" is the more
+highly recommended.
+.PP
+The aperture list is specified by \fBapert\fR in terms of \fBscale\fR.
+The apertures can be entered in any order but are sorted on output.
+\fBApert\fR can be string or the name of a text file containing the
+list of apertures. Apertures can either be listed individually and
+separated by whitespace or commas or a ranges notation of the
+form apstart:apend:apstep can be used.
+These can be set interactively from within the \fBphot\fR task.
+.PP
+Examples of valid aperture strings are listed below.
+
+.nf
+\f(CW
+	1 2 3
+	1.0,2.0,3.0
+	1:10:1
+\fR
+.fi
+
+.PP
+An arbitrary zero point is applied to the magnitude scale with \fBzmag\fR.
+The user can accept the default or experiment with his/her data until
+a suitable value is found. The computation of the magnitude errors
+does not depend on the zero point.
+.PP
+If \fBmkapert\fR = yes, the \fBphot\fR task will draw the concentric
+apertures on the display.  At present this option
+works only if \fBdisplay\fR = "stdgraph".
+
+.NH 2
+The QPHOT Task
+.PP
+\fBQphot\fP computes accurate centers, sky values and magnitudes for a list
+of objects using a restricted subset of the full \fBphot\fP parameter set.
+It is intended to be a quick look photometer suitable for use when 
+observing on the mountain or in well behaved uncrowded stellar fields.
+.PP
+The user is automatically queried for the critical parameters \fBcbox\fP,
+\fBannulus\fP, \fBdannulus\fP and \fBapertures\fP which are defined in
+terms of pixels.  The noise characteristics of the detector are assumed
+to obey Poisson statistics.  \fBQphot\fP computes centers for each
+object using the "centroid" centering algorithm.  Sky values are
+calculated using the "mode" algorithm.  The user can set the zero point
+of the magnitude scale, \fBzmag\fP, the gain of the detector, \fBepadu\fP,
+and exposure time image header keyword, \fBexposure\fP, but all the
+remaining parameters are set to their default values.
+.PP
+\fBQphot\fP can be driven by the image cursor or a coordinate list in
+interactive mode or by a coordinate list in batch mode in exactly 
+the same manner as the \fBphot\fP task.
+
+.NH 2
+The \fBPOLYPHOT\fP Task
+.PP
+\fBPolyphot\fP computes accurate centers, sky values and magnitudes for
+a list of objects using polygonal shaped apertures.  It is most suitable
+for measuring the magnitudes of large extended irregularly shaped objects.
+.PP
+\fBPolyphot\fP uses \fBdatapars\fP, \fBcenterpars\fP, and
+\fBfitskypars\fP in exactly the same manner as the \fBphot\fP task.  In
+general users should set the task parameters in the same way as they
+set them in \fBphot\fP.  However users who have defined their polygonal
+apertures interactively may wish to set the centering algorithm
+parameter \fBcalgorithm =\fP "none", to avoid the task trying to center
+on the brightest feature in the aperture.
+.PP
+The apertures are defined either interactively with the image or graphics
+cursor or by two files \fBpolygons\fP and \fBcoords\fP.
+Polygons defines the shape of the polygonal aperture and coords defines the
+initial positions of the apertures.  The polygons file may contain
+more than one aperture and the flux through each aperture may be measured
+at more than one position.  A detailed description of the file formats
+is given in section 6.4
+
+.NH
+Creating A Coordinate List
+.PP
+All APPHOT tasks operate on either lists of object coordinates or
+interactive cursor
+input. Lists are maintained as text files, one object per line with the x
+and y coordinates in columns one and two respectively. The coordinate and
+polygon files required by the \fBpolyphot\fR task have a different
+format which is described below. List files may be
+created interactively with either the graphics or the image cursor, by a
+previously executed APPHOT task, by a previously executed IRAF task or by
+a user program. Various means of creating coordinate lists within IRAF
+are described below. Comments preceded by a # character and blank lines
+are ignored.
+
+.nf
+\f(CW
+                     #Sample Coordinate List
+                        53.6    83.25
+                        100.0   35.8
+                        2.134   86.89
+                        ....    ....
+\fR
+.fi
+
+.NH 2
+Daofind
+.PP
+\fBDaofind\fR is an APPHOT task which detects stellar objects in an image 
+automatically. The user sets the \fBfwhmpsf\fR of the psf for which the
+detection algorithm is to be
+optimized as well as an intensity threshold for detection. \fBDaofind\fR
+locates all the qualifying stars  and writes their positions, rough magnitudes
+and shape characteristics to a file. This file can then be assigned to
+the \fBphot\fR task \fBcoords\fR parameter and read directly.
+.PP
+For example if we have an image containing stars for which the \fBfwhmpsf\fR
+is 4.0 pixels and the sigma of the sky background is 10 we might run
+\fBdaofind\fR as follows,
+
+.nf
+	\f(CWcl> daofind image fwhmpsf=4.0 threshold=30.0\fR
+.fi
+
+where we have set our detection threshold at 3.0 * sigma.
+
+.NH 2
+Imtool On the SUN Machines
+.PP
+The SUN IRAF \fBimtool\fR facility supports both image world coordinate
+systems and output coordinate files.  Coordinate lists can be created
+interactively by the users in the following way.
+.PP
+Display the IRAF image in the imtool window using the \fBdisplay\fR task.
+Move the mouse to the top of the \fBimtool\fR window, press the right mouse
+button to enter the \fBimtool\fR menu, move the mouse to the setup option and
+release the mouse button. Press
+the return key until the black triangle is opposite the coordinate list file
+name parameter.
+Delete the default file name, enter the full host system path name of the 
+desired coordinate file and press return. This name should now appear at
+the top of the imtool window.
+Move the mouse to the quit option and press the left mouse button to
+quit the setup window.
+.PP
+To enter the \fBimtool\fR cursor readout mode type the \fBF6\fR key.
+The x, y and intensity values at the cursor position
+are displayed in the lower right corner of the image.
+To mark stars and output their coordinates to the coordinate file, move
+the image cursor a star and press the left mouse button. A sequence number
+will appear on the display next to the marked position. The numbers can
+be changed from black to white and vice versa by toggling the \fBF5\fR key.
+The coordinate files are opened in append mode in order that stars may be
+added to an already existing list. \fBImtool\fR coordinate files are directly
+readable by all APPHOT tasks.
+
+.NH 2
+Rgcursor and Rimcursor
+.PP
+The LISTS package tasks \fBrgcursor\fR and \fBrimcursor\fR can be used to
+generate coordinate lists interactively. For example a coordinate
+list can be created interactively using the display cursor and
+the image display.
+
+.nf
+\f(CW
+	cl> display image
+
+	... image appears on the display ...
+
+	cl> rimcursor > image.coo
+
+	... move display cursor to stars of interest and tape space bar ...
+
+	... type ^Z to terminate the list ...
+\fR
+.fi
+
+Similarly a coordinate list
+can be created using the graphics cursor and a contour
+plot as shown below.
+
+.nf
+\f(CW
+	cl> contour image
+
+	... contour plot appears on the terminal ...
+
+	cl> rgcursor > image.coo
+
+	... move cursor to stars of interest and tap space bar ...
+
+	... type ^Z to terminate the list ...
+\fR
+.fi
+
+The text file "image.coo" contains the x and y coordinates of the marked stars
+in image pixel units. The output of \fBrimcursor\fR or  \fBrgcursor\fR can
+be read directly by the APPHOT \fBphot\fR task.
+\fBRimcursor\fR is only available in IRAF versions 2.7 and later and
+only for selected devices.
+
+.NH 2
+The Polygon List
+.PP
+A utility routine \fBpolymark\fR has been added to the APPHOT package to
+generate polygon and initial center lists for the \fBpolyphot\fR task.
+The format of the polygon files is 1 vertex per line with the 
+x and y coordinates of the vertex in columns 1 and 2 respectively.
+A line containing the single character ';' terminates the lists of vertices.
+There can be more than one polygon in a single polygon file.
+
+.nf
+\f(CW
+            Sample Polygon File
+
+                1.0   1.0
+                1.0   51.0
+                51.0  51.0
+                51.0  1.0
+                ;
+                80.0  80.0
+                80.0  131.0
+                131.0 131.0
+                131.0 80.0
+                ;
+\fR
+.fi
+
+.PP
+The accompanying coordinate file is optional. If no coordinate file is given
+the initial center for the polygon is the mean of its vertices in the 
+polygon file. If a
+coordinate file is specified the initial center for the polygon is the
+position in the coordinate file. Each polygonal aperture may be moved
+to several positions.
+
+.nf
+\f(CW
+       Sample Polyphot Coords File
+
+               50. 30.
+               80. 100.
+               60. 33.
+               ;
+               90. 50.
+               55. 90.
+               12. 122.
+               ;
+\fR
+.fi
+
+For example all the coordinates in group 1 will be measured using the
+aperture defined by polygon 1 and all the coordinates
+in group 2 will be measured with the aperture defined by polygon 2.
+
+.NH 2
+User Program
+.PP
+Obviously any user program which produces a text file with the coordinates
+listed 1 per line with x and y in columns 1 and 2 can be used to produce
+APPHOT coordinate files.
+
+.NH 2
+Modifying an Existing Coordinate List
+.PP
+The LISTS package routine \fBlintran\fR has been linked into the APPHOT
+package. It can be used to perform simple coordinate transformations on
+coordinate lists including shifts, magnifications, and rotations.
+
+.NH
+Running Apphot in Interactive Mode Without a Coordinate List
+.PP
+There are currently three ways to run the \fBphot\fR interactively without
+a coordinate list:
+1) read image display cursor commands 2) read 
+graphics cursor commands 3) read commands
+from the standard input. The three methods are briefly discussed below.
+Detailed examples of all three methods of operation can be found in
+the manual pages for each task.
+
+.NH 2
+Reading Image Cursor Commands
+.PP
+The default method of running APPHOT. The user loads an image onto
+the display, types \fBphot\fR and enters the image name. The image cursor
+appears on the display and the program is ready to accept user commands.
+This option is not available under IRAF version 2.6 and earlier
+because interactive image cursor readback was not available.
+
+.NH 2
+Redirecting the Image Cursor to the Graphics Cursor
+.PP
+\fBPhot\fR reads the graphics cursor and executes various keystroke
+commands. The environment variable \fBstdimcur\fR must be set to "stdgraph".
+For full access
+to all the graphics commands the parameter \fBdisplay\fR must also be set
+to "stdgraph".
+The user creates a contour plot of the image on the graphics terminal
+with the \fBcontour\fR task, types \fBphot\fR and answers the image name query.
+The graphics cursor appears on the contour plot ready for input.
+The user can move around the plot with the cursor successively marking stars.
+
+.NH 2
+Redirecting the Image Cursor to the Standard Input
+.PP
+The user can enter cursor commands directly on the standard input.
+The environment variable \fBstdimcur\fR must be set to "text".
+When the user types the task name \fBphot\fR and enters the image
+name, the following prompt appears.
+
+.nf
+	\f(CWImage cursor [xcoord ycoord wcs] key [cmd]:\fR
+.fi
+
+\fIXcoord\fR and \fIycoord\fR are the coordinates of the object of
+interest, \fIwcs\fR is the current world coordinate system, always 1,
+\fIkey\fR is a single
+character and \fIcmd\fR is an APPHOT task command.
+To perform the default action of
+the \fBphot\fR task the user responds as follows.
+
+.nf
+	\f(CWImage cursor [xcoord ycoord wcs] key [cmd]: 36. 42. 1\fR
+.fi
+
+\fBPhot\fR measures the magnitude of the star near pixel coordinates
+x,y = (36.,42.) and writes the result to the output file.
+In IRAF version 2.5 all the cursor command fields must be typed.
+The square brackets
+indicate those fields which are optional under IRAF version 2.6 and later.
+Users with SUN
+workstations may wish to combine the IMTOOL coordinate list cursor readback
+facilities which generate coordinate lists  with this mode of running APPHOT
+interactively.
+
+.NH 2
+The Interactive Keystroke Commands
+.PP
+A conscious effort has been made to keep the definitions of all the
+keystroke commands within the APPHOT package as similar as possible.
+The following are the most commonly used  keystrokes in the APPHOT package.
+
+.NH 3
+The ? (Help) Keystroke Command
+.PP
+The ? key prints the help page describing the cursor keystroke and colon
+show commands for the specific APPHOT task. An abbreviated help page
+is typed by default when a user enters a task in interactive mode.
+The ? key can be typed at any point in the APPHOT task.
+
+.NH 3
+The :show (Set and Print parameter)  Commands
+.PP
+Any APPHOT parameter can be displayed by typing :\fIparameter\fR command
+in interactive mode.
+For example to show the current value of the \fBfwhmpsf\fR parameter
+type the following command.
+
+.nf
+	\f(CW:fwhmpsf\fR
+.fi
+
+To set any APPHOT parameter type :\fIparameter\fR "value". For example
+to set the \fBfwhmpsf\fR to 2.0 type.
+
+.nf
+	\f(CW:fwhmpsf 2.0\fR
+.fi
+
+To display all the centering parameters type.
+
+.nf
+	\f(CW:show center\fR
+.fi
+
+Similarly the sky fitting and photometry parameters can be displayed by
+typing. 
+
+.nf
+	\f(CW:show sky\fR
+	\f(CW:show phot\fR
+.fi
+
+All the parameters can be displayed with the following command.
+
+.nf
+	\f(CW:show\fR
+.fi
+
+.NH 3
+The i (Interactive Setup) Keystroke Command
+.PP
+This extremely useful key allows one to set up the principal APPHOT
+parameters interactively. To use this feature move the image cursor to a star on
+the display, or move the graphics cursor to a star on the contour plot
+and tap the i key,
+or enter the x and y  coordinates, and the world coordinate system
+of the star and the i key manually. The program will query the user for
+the size of the extraction box and plot a radial profile of the star
+on the terminal. The user sets the \fBfwhmpsf\fR, the centering
+aperture \fBcbox\fR, the inner sky annulus \fBannulus\fR and \fBdannulus\fR,
+the list of apertures \fBaperts\fR and the data \fBsigma\fR,
+\fBthreshold\fR and \fBcthreshold\fR using the graphics cursor and the
+radial profile plot.
+The cursor comes up on the plot at the position of the appropriate parameter.
+Typing return will preserve the old value.
+If the cursor is outside the range of values on the plot the old value
+is kept.
+.PP
+Setting \fBsigma\fP, \fBcthreshold\fP, and \fBthreshold\fP 
+interactively requires two keystrokes.  In each case the measured parameter
+is the difference between the two y coordinates of the graphics
+cursor. It is recommended in general that the user leave \fBcthreshold\fP
+at zero.
+
+.NH 3
+The v (Verify) Keystroke Command
+.PP
+The v key verifies that the values of the critical task parameters 
+currently in memory are the ones that the user wants.  To each verify query
+the user either types CR to verify the current value or enters a new
+value.
+
+.NH 3
+The w (Write to Psets) Keystroke Command
+.PP
+The w key writes the current values of the parameters in memory to the
+appropriate psets.
+This feature is useful for saving values marked with the
+i key. On exiting APPHOT a prompt will remind the user that the current
+parameters in memory must be stored in the psets or lost.
+
+.NH 3
+The d (Radial Profile Plot) Keystroke Command
+.PP
+The d key plots a centered radial profile of a star on the graphics device.
+
+.NH 3
+The f (Fit) Keystroke Command
+.PP
+This key performs the default action of each APPHOT task without writing
+any results
+to the output file. In the \fBphot\fR task the f key will center, fit the
+local sky and compute the magnitudes for a star. This key allows the user to
+experiment interactively with the data, changing the default parameters,
+remeasuring magnitudes and so on before actually writing out any data.
+
+.NH 3
+The Space Bar (Fit and Write out Results) Keystroke Command
+.PP
+This key performs the default action of the task and writes the results
+to the output catalog.
+
+.NH
+Running Apphot In Interactive Mode From A Coordinate List
+.PP
+This is currently the best method for running APPHOT interactively for users
+without image cursor readback facilities. APPHOT tasks
+can pick stars out of the list sequentially or by number,  measure stars
+sequentially or by number, rewind the coordinate lists and remeasure all
+the stars. Stars which are not in the coordinate list can still be
+measured and added to the output catalog.
+
+.IP [1] 
+The :m (Move) Keystroke Command
+.RS
+.LP
+This command moves the cursor to the next or a specified star in the
+coordinate list.  If the hardware cursor on the
+device being read from is enabled the actual physical cursor will move
+to the requested star. For
+example a user might decide that star # 10 in the coordinate list is the best
+setup star. He/she simply types a :m 10 to move to the star in
+question followed by the i key to setup the parameters interactively.
+.RE
+
+.IP [2]
+The :n (Next)  Keystroke Command
+.RS
+.LP
+This command moves to the next or specified star in the list, performs the
+default action of the task and writes the results to the output file.
+This key is particularly useful in examining the results of a large batch
+run.
+For example, a user measures the magnitudes of 500 stars using APPHOT in
+batch mode.  He/she is suspicious about the results for twenty of the most
+crowded stars. By rerunning APPHOT in interactive mode using the original
+coordinate list, the user can selectively call up the stars in question,
+plot their radial profiles, and examine the results interactively.
+.RE
+
+.IP [3]
+The l (List) Keystroke Command
+.RS
+.LP
+This command measures all the stars in the coordinate list sequentially from
+the current position in the file.
+.RE
+
+.IP [4]
+The r (Rewind) Keystroke Command
+.RS
+.LP
+This command rewinds the coordinate list.
+.RE
+
+.NH
+Running Apphot in Batch Mode
+.PP
+This is the simplest way to run APPHOT. Once the parameters are set and stored
+in the pset files the program can be run in batch by setting the parameter
+\fBinteractive\fR = no. The program will read the coordinate list
+sequentially computing results for each star and writing them to the
+output file.
+
+.NH
+Apphot Output
+.PP
+APPHOT tasks write their output to text and/or plot files as well as to the
+standard output and graphics terminals.
+
+.NH 2
+Text Files
+.PP
+All APPHOT records are written to text files.
+The parameters for the task are listed at the beginning of each APPHOT
+output text file and identified with a #K string.
+The header record is not written until the record
+for the first star is to be written to the database. Parameter changes  will
+generate a one line entry in the output text file.
+The data records follow the header record in the order in which they
+were computed.
+If the output file parameter \fBoutput\fR = "" no output file is written.
+This is  the default action for the \fBradprof\fR task.
+If \fBoutput\fR = "default",
+the output file name is constructed using the image name.
+
+.NH 2
+Plot Files
+.PP
+Some APPHOT tasks can optionally produce graphics output.
+These files are maintained as plot metacode and may contain many individual
+plots.
+A directory of plots in each metacode file can be obtained with
+\fBgkidir\fR. Individual plots can be extracted with \fBgkiextract\fR and
+combined and plotted with \fBgkimosaic\fR.  
+
+.NH 2
+Running Apselect on Apphot Output Files 
+.PP
+Individual fields can be extracted from the APPHOT output files using
+the \fBapselect\fR task and a keyword and expression scheme.
+For example the user may wish
+to extract the x and y center coordinates, the sky value and the
+magnitudes from the APPHOT \fBphot\fR catalog. Using apselect they
+would type.
+
+.nf
+	\f(CWcl> apselect output xc,yc,msky,mag yes > magsfile\fR
+.fi
+
+The selected fields would appear in the textfile "magsfile".
+
+.NH
+Apphot Recipes
+.PP
+In the following section three APPHOT reduction sessions which illustrate
+different methods of using the APPHOT package are described. In the
+first example the user wishes to compute magnitudes for a large number
+of stars in a single image. In the second example he/she wishes to
+measure the magnitude of a single standard star in each of a long list of
+images. Finally in the last example the user wishes to measure the
+magnitude of an elliptical galaxy through a list of apertures.
+Each example assumes that the user has started with the default set of
+package parameters.
+
+.NH 2
+Infrared photometry of a Star Field in Orion
+.PP
+An observer has an IRAF image on disk of a star forming region in Orion taken
+with the
+IR CCD camera. The Orion image is a composite formed from 64 separate
+IR images using the PROTO \fBirmosaic\fR and \fBiralign\fR tasks.
+The Orion image contains about 400 stars but is only moderately crowded. The
+observer decides to use the APPHOT package to reduce his data.
+.PP
+The observer decides to run the \fBdaofind\fR routines to create a coordinate
+list of stars, to run \fBphot\fR in interactive mode with the image cursor
+directed to the standard input to setup and store the \fBphot\fR task
+parameters and finally, to run \fBphot\fR in batch mode to do the photometry.
+.PP
+To create the coordinate list the user needs to supply the full width half
+maximum of the pointspread function and an intensity threshold
+above background to the
+\fBdaofind\fR program. Using the PLOT package task \fBimplot\fR the user
+examines several stars in the image and decides that the \fBfwhmpsf\fR
+should be 3.0
+pixels and that the standard deviation of the background should be 10.0
+counts.
+The user decides to include all stars with a peak intensity greater
+than five standard deviations above local background in the coordinate list.
+The user runs \fBdaofind\fR as follows.
+
+.nf
+	\f(CWap> daofind orion fwhmpsf=3.0 threshold=50.0\fR
+.fi
+
+The x and y coordinates, a magnitude estimate and some statistics on image
+sharpness and roundness are output to the file "orion.coo.1".
+The user can obtain a printout of the coordinate
+list by typing.
+
+.nf
+	\f(CWap> lprint orion.coo.1\fR
+.fi
+
+.PP
+Next the user decides to set up the parameters of the \fBphot\fR task.
+Using the \fBepar\fR task he enters the phot task parameter menu,
+types "orion" opposite the \fBimage\fR parameter and "orion.coo.1"
+opposite the \fBcoords\fR parameter. Next he moves the cursor opposite
+the \fBdatapars\fR parameter and types \fB:e\fR to enter the \fBdatapars\fR
+menu. He sets the gain parameter \fBepadu\fR to 5.0 electrons per adu
+and the readout noise \fBreadnoise\fR to 5.0 electrons. He types \fB:q\fR to
+quit and save the \fBdatapars\fR parameters and \fB^Z\fR to quit and save the
+\fBphot\fR parameters.
+.PP
+Now the user is ready to enter the \fBphot\fR task in interactive mode to set
+up the remaining data dependent parameters. The user types  the following
+sequence of commands in response to the cursor prompt. Note that the
+example below assumes that the image cursor has been directed to the
+standard input. The image cursor comes up on the screen in the form of
+a prompt. This example could equally well be run from the image hardware
+cursor in which case the cursor would appear on the displayed image. The
+keystroke commands are identical in the two cases.
+
+.br
+
+.nf
+\f(CW
+	ap> phot orion
+
+	... \fIload the phot task\fR ...
+
+	Image cursor [xcoord ycoord wcs] key [cmd]: ?
+
+	... \fIprint help page for phot task\fR ...
+
+	Image cursor [xcoord ycoord wcs] key [cmd]: :radplots yes
+
+	... \fIenable radial profile plotting\fR ...
+
+	Image cursor [xcoord ycoord wcs] key [cmd]: :m 10
+
+	... \fImove to star 10 in the coordinate list\fR ...
+
+	Image cursor [xcoord ycoord wcs] key [cmd]: i
+
+	... \fIenter interactive setup mode using star 10\fR ...
+
+	... \fImark fwhmpsf, cbox, sky annulus, apertures on the plot\fR ...
+
+        ... \fIleave sigma and cthreshold at their default values\fR ...
+
+	... \fIcheck answers on radial profile plot of the results\fR ...
+
+	Image cursor [xcoord ycoord wcs] key [cmd]: v
+
+        ... \fIverify the critical parameters\fR ...
+
+	Image cursor [xcoord ycoord wcs] key [cmd]: :radplots no
+
+	... \fIdisable radial profile plotting\fR ...
+
+	Image cursor [xcoord ycoord wcs] key [cmd]: w
+
+	... \fIstore new parameters in the psets\fR ...
+
+	Image cursor [xcoord ycoord wcs] key [cmd]: q
+
+	... \fIquit interactive cursor loop\fR ...
+
+	q
+
+	... \fIquit the phot task\fR ...
+
+\fR
+.fi
+.PP
+The user decides he is happy with the current parameter set and decides
+to run the \fBphot\fR task in batch and submit it as a background task.
+
+.nf
+	\f(CWap> phot orion inter- verify- &\fR
+.fi
+
+The results will appear in the text file "orion.mag.1".
+
+.NH 2
+Landolt Standards 
+.PP
+The user has 100 UBVRI images of 20 Landolt Standards
+taken on a single night. These frames have been taken at various short
+exposures.
+The user wishes to process all this data
+in batch mode with the output records going to a single file.
+.PP
+The observer decides to run the \fBdaofind\fR task to create a coordinate
+list for each image, to run \fBphot\fR on a representative image
+in interactive mode with the image cursor
+directed to the standard input to set up and store the \fBphot\fR task
+parameters, and finally to run \fBphot\fR in batch mode on all the images
+to do the photometry.
+.PP
+Note that the example below assumes that the image cursor has been redirected
+to the standard input.  The image cursor comes up on the screen in the
+form of a prompt.  This example could equally well be run from the image 
+hardware cursor in which case the cursor would appear on the displayed
+image.  The keystroke commands are identical in the two cases.
+.PP
+To create the coordinate list the user needs to supply the full width half
+maximum of the point spread function and an intensity threshold above
+local background to the
+\fBdaofind\fR task. Using the PLOT package task \fBimplot\fR the user
+examines the Landolt standards in several images and decides that the
+average \fBfwhmpsf\fR is 4.3
+pixels and that the standard deviation of the background is 15.0 counts.
+Note that if the user has access to an image display \fBfwhmpsf\fP and
+\fBthreshold\fP can be determined interactively from inside the
+daofind task itself.
+The user decides to include all stars with a peak intensity greater
+than five standard deviations above local background in the coordinate list,
+which should include weak and spurious objects.
+The user runs \fBdaofind\fR as follows.
+
+.nf
+	\f(CWap> daofind lan*.imh fwhmpsf=4.3 threshold=75.0 verify- &\fP
+.fi
+
+The x and y coordinates, an initial guess at the magnitude and some
+sharpness and roundness characteristics are output to the files "lan*.coo.1".
+For example the image lan100350.imh will now have a corresponding 
+coordinate file lan100350.coo;1. The user may wish at this point
+to quickly check the coordinate files for spurious objects.
+.PP
+Next the user decides to set up the parameters of the phot task.
+Using the \fBepar\fR task he enters the phot task parameter set,
+enters "lan100350b" opposite the \fBimage\fR parameter and "lan100350b.coo.1"
+opposite the \fBcoords\fR parameter. Next he moves the cursor opposite
+the \fBdatapars\fR parameter and types \fB:e\fR to enter the \fBdatapars\fR
+menu. He sets the gain parameter \fBepadu\fR to 10 electrons per adu
+and the readout noise \fBreadnoise\fR to 50.0 electrons. 
+Finally in order to normalize all the magnitudes the user enters
+the image header exposure time keyword "itime" opposite the
+\fBexposure\fP parameter.  He types \fB:q\fR to
+quit and save the \fBdatapars\fR parameters and \fB^Z\fR to quit and save the
+\fBphot\fR parameters.
+.PP
+Now the user is ready to enter the \fBphot\fR task in interactive mode to set
+up the remaining data dependent parameters. The user types  the following
+sequence of commands in response to the cursor prompt.
+
+.nf
+\f(CW
+	ap> phot lan100350.imh
+
+	... \fIload the phot task\fR ...
+
+	Image cursor [xcoord ycoord wcs] key [cmd]: ?
+
+	... \fIprint help page for phot task\fR ...
+
+	Image cursor [xcoord ycoord wcs] key [cmd]: :radplots yes
+
+	... \fIenable radial profile plotting\fR ...
+
+	Image cursor [xcoord ycoord wcs] key [cmd]: :m #n
+
+	... \fImove to star n in the coordinate list\fR ...
+
+	Image cursor [xcoord ycoord wcs] key [cmd]: i
+
+	... \fIenter interactive setup mode using star n\fR ...
+
+	... \fImark fwhmpsf, cbox, sky annulus, apertures on the plot\fR ...
+
+        ... \fIleave sigma and cthreshold at their default values\fR ...
+
+	... \fIcheck answers on radial profile plot of the results\fR ...
+
+	Image cursor [xcoord ycoord wcs] key [cmd]: v
+
+        ... \fIverify the critical parameters\fR ...
+
+	Image cursor [xcoord ycoord wcs] key [cmd]: :radplots no
+
+	... \fIdisable radial profile plotting\fR ...
+
+	Image cursor [xcoord ycoord wcs] key [cmd]: w
+
+	... \fIstore new parameters in the psets\fR ...
+
+	Image cursor [xcoord ycoord wcs] key [cmd]: q
+
+	... \fIquit interactive cursor loop\fR ...
+
+	q
+
+	... \fIquit the phot task\fR ...
+
+\fR
+.fi
+.PP
+Finally the user runs the \fBphot\fR task on the full list of images,
+with their corresponding parameter sets and dumps the output to a single
+text file named "output".
+
+.nf
+	\f(CWap> phot lan*.imh coords="lan*.coo.*" output=output veri- inter- &\fR
+.fi
+
+The results will appear in the text file "output".
+
+.NH 2
+Aperture Photometry of an Elliptical Galaxy
+.PP
+The user has a single image of the elliptical galaxy N315. She
+wishes to measure the magnitude of this galaxy through a list of apertures
+equal to those published in a well known catalogue of photoelectric photometry.
+Her data has been sky subtracted to give an average background value of 0.0
+and the standard deviation of the sky background is 20.0 counts.
+From the published aperture photometry
+and the scale of her telescope she knows that she wishes to measure
+the galaxy through aperture radii of 10.5, 15.2, 20.8, and 25.6 arc seconds.
+.PP
+The user wishes to work in interactive mode using a contour plot
+of the image and the graphics cursor to enter commands to the \fBphot\fR
+task. She therefore sets the image cursor to "stdgraph" as follows.
+
+.nf
+	\f(CWap> set stdimcur = stdgraph\fR
+.fi
+
+.PP
+Next she makes a contour plot of the image and  writes it to
+a plot metacode file as follows.
+
+.nf
+\f(CW
+	ap> contour N315 
+
+	... \fIcontour plot appears on the terminal\fR ...
+
+	ap> =gcur
+
+	... \fIenter cursor mode\fR ...
+
+	:.write n315.plot
+
+	... \fIwrite the plot to a file\fR ...
+
+	q
+
+	... \fIexit cursor mode\fR ...
+
+\fR
+.fi
+.PP
+Now the user is ready to set up the parameters of the \fBphot\fR task.
+Since she already knows the values of the parameters she wishes to use
+she types
+
+.nf
+	\f(CWap> epar phot\fR
+.fi
+
+to enter the phot task menu. She positions the cursor opposite
+\fBimage\fR parameter and types "N315", opposite \fBdispay\fR and
+types "stdgraph".
+Next she moves the cursor opposite
+the \fBdatapars\fR parameter and types \fB:e\fR to enter the \fBdatapars\fR
+menu. She makes sure that \fBscale =\fP 0.75 arc-seconds per pixel the scale
+of the telescope, sets the standard deviation
+of the sky background \fBsigma\fR to 20.0, sets the gain
+parameter \fBepadu\fR to 5 electrons per adu
+and the readout noise \fBreadnoise\fR to 5.0 electrons. She types \fB:q\fR to
+quit and save the \fBdatapars\fR parameters. She decides to leave the
+centering parameters in \fBcenterpars\fR at their default values.
+\fBCbox\fP in particular will be 5.0 arcseconds wide.  The user
+has already removed a low order polynomial sky background from this image.
+She wishes to fix the sky value at 0.0. She moves the cursor opposite
+the \fBfitskypars\fR parameter and types \fB:e\fR to enter the sky fitting menu.
+She types "constant" opposite the \fBsalgorithm\fR parameter, "0.0"
+opposite the \fBskyvalue\fR parameter and \fB:e\fR to exit
+the sky fitting parameter menu. Finally she enters the \fBphotpars\fR
+menu and enters the aperture string "10.5,15.2,20.8,25.6" opposite
+the \fBapert\fR parameter. 
+.PP
+To measure the galaxy she types
+
+.nf
+	\f(CWap> phot N315\fR
+.fi
+
+to enter the phot task, positions the cursor on the center of the
+galaxy in the contour plot and taps the space bar to make the measurement.
+The results are  written to the file "N315.mag.1".
diff --git a/noao/digiphot/apphot/doc/wphot.hlp b/noao/digiphot/apphot/doc/wphot.hlp
new file mode 100644
index 00000000..69bfd7c7
--- /dev/null
+++ b/noao/digiphot/apphot/doc/wphot.hlp
@@ -0,0 +1,780 @@
+.help wphot May00 noao.digiphot.apphot
+.ih
+NAME
+wphot -- perform weighted aperture photometry on a list of stars
+.ih
+USAGE
+wphot image
+.ih
+PARAMETERS
+.ls image
+The list of images containing the objects to be measured.
+.le
+.ls skyfile = ""
+The list of text files containing the sky values, of the measured objects,
+one object per line with x, y, the sky value, sky sigma, sky skew, number of sky
+pixels and number of rejected sky pixels in columns one to seven respectively.
+The number of sky files must be zero, one, or equal to the number of input
+images. A skyfile value is only requested if \fIfitskypars.salgorithm\fR =
+"file" and if WPHOT is run non-interactively.
+.le
+.ls coords = ""
+The list of text files containing initial coordinates for the objects to
+be centered. Objects are listed in coords one object per line with the
+initial coordinate values in columns one and two. The number of coordinate
+files must be zero, one, or equal to the number of images. If coords is
+"default", "dir$default", or a directory specification then a coords file name
+of the form dir$root.extension.version is constructed, where dir is the
+directory, root is the root image name, extension is "coo" and version is
+the next available version number for the file.
+.le
+.ls output = "default"
+The name of the results file or results directory. If output is
+"default", "dir$default", or a directory specification then an output file name
+of the form dir$root.extension.version is constructed, where dir is the
+directory, root is the root image name, extension is "omag" and version is
+the next available version number for the file. The number of output files
+must be zero, one, or equal to the number of image files.  In both interactive
+and batch mode full output is written to output. In interactive mode
+an output summary is also written to the standard output.
+.le
+.ls plotfile = ""
+The name of the file containing radial profile plots of the stars written
+to the output file. If plotfile is defined then a radial profile plot
+is written to plotfile every time a record is written to \fIoutput\fR.
+The user should be aware that this can be a time consuming operation.
+.le
+.ls datapars = ""
+The name of the file containing the data dependent parameters. The critical
+parameters \fIfwhmpsf\fR and \fIsigma\fR are located here. If \fIdatapars\fR
+is undefined then the default parameter set in uparm directory is used.
+.le
+.ls centerpars = ""
+The name of the file containing the centering parameters. The critical
+parameters \fIcalgorithm\fR and \fIcbox\fR are located here.
+If \fIcenterpars\fR is undefined then the default parameter set in
+uparm directory is used.
+.le
+.ls fitskypars = ""
+The name of the text file containing the sky fitting parameters. The critical
+parameters \fIsalgorithm\fR, \fIannulus\fR, and \fIdannulus\fR are located here.
+If \fIfitskypars\fR is undefined then the default parameter set in uparm
+directory is used.
+.le
+.ls photpars = ""
+The name of the file containing the photometry parameters. The critical
+parameter \fIapertures\fR is located here.  If \fIphotpars\fR is undefined
+then the default parameter set in uparm directory is used.
+.le
+.ls interactive = yes
+Run the task interactively ?
+.le
+.ls radplots = no
+If \fIradplots\fR is "yes" and PHOT is run in interactive mode, a radial
+profile of each star is plotted on the screen after the star is measured.
+.le
+.ls icommands = ""
+The image display cursor or image cursor command file.
+.le
+.ls gcommands = ""
+The graphics cursor or graphics cursor command file.
+.le
+.ls wcsin = ")_.wcsin", wcsout = ")_.wcsout"
+The coordinate system of the input coordinates read from \fIcoords\fR and
+of the output coordinates written to \fIoutput\fR respectively. The image
+header coordinate system is used to transform from the input coordinate
+system to the "logical" pixel coordinate system used internally,
+and from the internal "logical" pixel coordinate system to the output
+coordinate system. The input coordinate system options are "logical", tv",
+"physical", and "world". The output coordinate system options are "logical",
+"tv", and "physical". The image cursor coordinate system is assumed to
+be the "tv" system.
+.ls logical
+Logical coordinates are pixel coordinates relative to the current image.
+The  logical coordinate system is the coordinate system used by the image
+input/output routines to access the image data on disk. In the logical
+coordinate system the coordinates of the first pixel of a  2D image, e.g.
+dev$ypix  and a 2D image section, e.g. dev$ypix[200:300,200:300] are
+always (1,1).
+.le
+.ls tv
+Tv coordinates are the pixel coordinates used by the display servers. Tv
+coordinates  include  the effects of any input image section, but do not
+include the effects of previous linear transformations. If the input
+image name does not include an image section, then tv coordinates are
+identical to logical coordinates.  If the input image name does include a
+section, and the input image has not been linearly transformed or copied from
+a parent image, tv coordinates are identical to physical coordinates.
+In the tv coordinate system the coordinates of the first pixel of a
+2D image, e.g. dev$ypix and a 2D image section, e.g. dev$ypix[200:300,200:300]
+are (1,1) and (200,200) respectively.
+.le
+.ls physical
+Physical coordinates are pixel coordinates invariant  with respect to linear
+transformations of the physical image data.  For example, if the current image
+was created by extracting a section of another image,  the  physical
+coordinates of an object in the current image will be equal to the physical
+coordinates of the same object in the parent image,  although the logical
+coordinates will be different.  In the physical coordinate system the
+coordinates of the first pixel of a 2D image, e.g. dev$ypix and a 2D
+image section, e.g. dev$ypix[200:300,200:300] are (1,1) and (200,200)
+respectively.
+.le
+.ls world
+World coordinates are image coordinates in any units which are invariant
+with respect to linear transformations of the physical image data. For
+example, the ra and dec of an object will always be the same no matter
+how the image is linearly transformed. The units of input world coordinates
+must be the same as those expected by the image header wcs, e. g.
+degrees and degrees for celestial coordinate systems.
+.le
+The wcsin and wcsout parameters default to the values of the package
+parameters of the same name. The default values of the package parameters
+wcsin and wcsout are "logical" and "logical" respectively.
+.le
+.le
+.ls cache = ")_.cache"
+Cache the image pixels in memory. Cache may be set to the value of the apphot
+package parameter (the default), "yes", or "no". By default cacheing is 
+disabled.
+.le
+.ls verify = ")_.verify"
+Verify the critical parameters in non-interactive mode.  Verify may be set to
+the apphot package parameter value (the default), "yes", or "no".
+.le
+.ls update = ")_.update"
+Update the critical parameters in non-interactive mode if verify is yes.
+Update may be set to the apphot package parameter value (the default), "yes",
+or "no".
+
+.le
+.ls verbose = ")_.verbose"
+Print messages on the terminal about actions taken in non-interactive mode.
+Verbose may be set to the apphot package parameter value (the default), "yes",
+or "no".
+.le
+.ls graphics = ")_.graphics"
+The default graphics device. Graphics may be set to the apphot package
+parameter value (the default), "yes", or "no".
+
+.le
+.ls display = ")_.display"
+The default display device. Graphics may be set to the apphot package
+parameter value (the default), "yes", or "no. By default graphics overlay
+is disabled.  Setting display to one of "imdr", "imdg", "imdb", or "imdy"
+enables graphics overlay with the IMD graphics kernel.  Setting display to
+"stdgraph" enables WPHOT to work interactively from a contour plot.
+.le
+
+.ih
+DESCRIPTION
+WPHOT computes accurate centers, sky values, and weighted magnitudes for a
+list of objects in the IRAF image \fIimage\fR whose initial coordinates are read
+from the text file \fIcoords\fR or image display cursor, and writes the
+computed x and y coordinates, sky values and magnitudes to the text file
+\fIoutput\fR.
+
+The coordinates read from \fIcoords\fR are assumed to be in coordinate
+system defined by \fIwcsin\fR. The options are "logical", "tv", "physical",
+and "world" and the transformation from the input coordinate system to
+the internal "logical" system is defined by the image coordinate system.
+The simplest default is the "logical" pixel system. Users working on with
+image sections but importing pixel coordinate lists generated from the parent
+image must use the "tv" or "physical" input coordinate systems.
+Users importing coordinate lists in world coordinates, e.g. ra and dec,
+must use the "world" coordinate system and may need to convert their
+equatorial coordinate units from hours and degrees to degrees and degrees first.
+
+The coordinates written to \fIoutput\fR are in the coordinate
+system defined by \fIwcsout\fR. The options are "logical", "tv",
+and "physical". The simplest default is the "logical" system. Users
+wishing to correlate the output coordinates of objects measured in
+image sections or mosaic pieces with coordinates in the parent
+image must use the "tv" or "physical" coordinate systems.
+
+If \fIcache\fR is yes and the host machine physical memory and working set size
+are large enough, the input image pixels are cached in memory. If cacheing
+is enabled and WPHOT is run interactively the first measurement will appear
+to take a long time as the entire image must be read in before the measurement
+is actually made. All subsequent measurements will be very fast because WPHOT
+is accessing memory not disk. The point of cacheing is to speed up random
+image access by making the internal image i/o buffers the same size as the
+image itself. However if the input object lists are sorted in row order and
+sparse cacheing may actually worsen not improve the execution time. Also at
+present there is no point in enabling cacheing for images that are less than
+or equal to 524288 bytes, i.e. the size of the test image dev$ypix, as the
+default image i/o buffer is exactly that size. However if the size of dev$ypix
+is doubled by converting it to a real image with the chpixtype task then the
+effect of cacheing in interactive is can be quite noticeable if measurements
+of objects in the top and bottom halfs of the image are alternated.
+
+In interactive mode the user may either define the list of objects to be
+measured interactively with the image cursor or create an object list prior
+to entering WPHOT.  In either case the user may adjust the centering, sky
+fitting and photometry parameters until a satisfactory fit is achieved and
+only then store the final results in \fIoutput\fR. In batch
+mode the initial positions are read from the text file \fIcoords\fR
+or the image cursor parameter \fIicommands\fR is redirected to a text
+file containing a list of cursor commands.
+
+.ih
+CURSOR COMMANDS
+
+The following list of cursor commands are currently available.
+
+.nf
+	Interactive Photometry Commands
+
+?	Print help
+:	Colon commands
+v	Verify the critical parameters
+w	Store the current parameters
+d	Plot radial profile of current star 
+i	Interactively set parameters using current star
+c	Fit center of current star
+t	Fit sky around the cursor
+a       Average sky values fit around several cursor positions
+s	Fit sky around the current star
+p	Do photometry for current star, using current sky
+o	Do photometry for current star, using current sky, output results
+f	Do photometry for current star
+spbar	Do photometry for current star, output results
+m	Move to next star in coordinate list
+n	Do photometry for next star in coordinate list, output results
+l	Do photometry for remaining stars in coordinate list, output results
+r	Rewind the coordinate list
+e	Print error messages
+q	Exit task
+
+
+	Colon Commands
+
+:show	[data/center/sky/fit]	Show parameters
+:m [n]	Move to next [nth] star in the coordinate list
+:n [n]	Do photometry for next [nth] star in coordinate list, output results
+
+
+	Colon Parameter Editing Commands
+
+# Image and file parameters
+
+:image		[string]	Image name
+:coords		[string]	Coordinate file name
+:output		[string]	Output file name
+
+# Data dependent parameters
+
+:scale		[value]		Image scale (units per pixel)
+:fwhmpsf	[value]		Full-width half-maximum of PSF (scale units)
+:emission	[y/n]		Emission features (y), absorption (n)
+:sigma	        [value]		Standard deviation of sky (counts)
+:datamin	[value]		Minimum good pixel value (counts)
+:datamax	[value]		Maximum good pixel value (counts)
+
+# Noise parameters
+
+:noise		[string]	Noise model (constant|poisson)
+:gain		[string]	Gain image header keyword
+:ccdread	[string]	Readout noise image header keyword
+:epadu		[value]		Gain (electrons  per adu)
+:readnoise	[value]		Readout noise (electrons)
+
+# Observations parameters
+
+:exposure	[string]	Exposure time image header keyword
+:airmass	[string]	Airmass image header keyword
+:filter		[string]	Filter image header keyword
+:obstime	[string]	Time of observation image header keyword
+:itime 		[value]		Integration time (time units)
+:xairmass	[value]		Airmass value (number)
+:ifilter	[string]	Filter id string
+:otime		[string]	Time of observations (time units)
+
+# Centering algorithm parameters
+
+:calgorithm	[string]	Centering algorithm
+:cbox		[value]		Width of the centering box (scale units)
+:cthreshold	[value]		Centering intensity threshold (sigma)
+:cmaxiter	[value]		Maximum number of iterations
+:maxshift	[value]		Maximum center shift (scale units)
+:minsnratio	[value]		Minimum S/N ratio for centering
+:clean		[y/n]		Clean subraster before centering
+:rclean		[value]		Cleaning radius (scale units)
+:rclip		[value]		Clipping radius (scale units)
+:kclean		[value]		Clean K-sigma rejection limit (sigma)
+
+# Sky fitting algorithm parameters
+
+:salgorithm	[string]	Sky fitting algorithm
+:skyvalue	[value]		User supplied sky value (counts)
+:annulus	[value]		Inner radius of sky annulus (scale units)
+:dannulus	[value]		Width of sky annulus (scale units)
+:khist		[value]		Sky histogram extent (+/- sigma)
+:binsize	[value]		Resolution of sky histogram (sigma)
+:smooth		[y/n]		Lucy smooth the sky histogram
+:sloclip	[value]		Low-side clipping factor in percent
+:shiclip	[value]		High-side clipping factor in percent
+:smaxiter	[value]		Maximum number of iterations
+:snreject	[value]		Maximum number of rejection cycles
+:sloreject	[value]		Low-side pixel rejection limits (sky sigma)
+:shireject	[value]		High-side pixel rejection limits (sky sigma)
+:rgrow		[value]		Region growing radius (scale units)
+
+# Photometry parameters
+
+:weighting	[string]	Weighting function (constant|cone|gauss)
+:apertures	[string]	List of aperture radii (scale units)
+:zmag		[value]		Zero point of magnitude scale
+
+# Plotting and marking parameters
+
+:mkcenter	[y/n]		Mark computed centers on display
+:mksky		[y/n]		Mark the sky annuli on the display
+:mkapert	[y/n]		Mark apertures on the display
+:radplot	[y/n]		Plot radial profile of object
+
+
+
+The following commands are available from inside the interactive setup menu.
+
+
+                    Interactive Phot/Wphot Setup Menu
+
+	v	Mark and verify the critical parameters (f,s,c,a,d,r)
+
+	f	Mark and verify the full-width half-maximum of psf
+	s	Mark and verify the standard deviation of the background
+	l	Mark and verify the minimum good data value
+	u	Mark and verify the maximum good data value
+
+	c	Mark and verify the centering box width
+	n	Mark and verify the cleaning radius
+	p	Mark and verify the clipping radius
+
+	a	Mark and verify the inner radius of the sky annulus
+	d	Mark and verify the width of the sky annulus
+	g	Mark and verify the region growing radius
+
+	r	Mark and verify the aperture radii
+.fi
+
+.ih
+ALGORITHMS
+
+WPHOT computes accurate centers for each object using the centering
+parameters defined in the CENTERPARS task, computes an accurate sky value
+for each object using the sky fitting parameters defined in FITSKYPARS task,
+and computes magnitudes using the photometry parameters defined in the
+PHOTPARS task. The data dependent parameter are defined in the DATAPARS task.
+
+Three weighting functions are currently supported: constant, cone and gauss.
+Constant weighting, the default gives identical results to the PHOT task.
+Pixels are weighted by the fraction of their area inside the circular
+aperture. For cone and gauss weighting an additional  triangular or gaussian
+weighting function of full width half maximum equal to \fIfwhmpsf\fR is
+applied to the pixels before aperture summing.
+
+This task is currently experimental. Further algorithm work is required.
+
+.ih
+OUTPUT
+
+In interactive mode the following quantities are printed on the standard
+output as each object is measured. Error is a simple string which
+indicates whether the task encountered any errors in the
+the centering algorithm, the sky fitting algorithm or the photometry
+algorithm. Mag and merr are the magnitudes and errors in
+apertures 1 through N respectively and xcenter, ycenter and msky are the
+x and y centers and the sky value respectively.
+
+.nf
+    image  xcenter  ycenter  msky  mag[1 ... N]   error
+.fi
+
+In both interactive and batch mode full output is written to the text file
+\fIoutput\fR. At the beginning of each file is a header listing the
+current values of the parameters when the first stellar record was written.
+These parameters can be subsequently altered. For each star measured the
+following record is written
+
+.nf
+	image  xinit  yinit  id  coords  lid
+	   xcenter  ycenter  xshift  yshift  xerr  yerr  cier error
+	   msky  stdev  sskew  nsky  nsrej  sier  serror
+	   itime  xairmass  ifilter otime
+	   rapert  sum  area  flux mag  merr  pier  perr
+.fi
+
+Image and coords are the name of the image and coordinate file respectively.
+Id and lid are the sequence numbers of stars in the output and coordinate
+files respectively. Cier and cerror are the error code and accompanying
+error message respectively.  Xinit, yinit, xcenter, ycenter, xshift, yshift,
+and xerr, yerr are self explanatory and output in pixel units. The sense of
+the xshift and yshift definitions is the following.
+
+.nf
+	xshift = xcenter - xinit
+	yshift = ycenter - yinit
+.fi
+
+Sier and serror are the error code and accompanying error message respectively.
+Msky, stdev and sskew are the best estimate of the sky value (per pixel),
+standard deviation and skew respectively. Nsky and nsrej are the number of
+sky pixels and the number of sky pixels rejected respectively.
+
+Itime is the exposure time, xairmass is self-evident, ifilter is an id
+string identifying the filter used during the observation, and otime is
+a string specifying the time of the observation in whatever units the
+user has defined.
+
+Rapert, sum, area, and flux are the radius of the aperture in pixels, the total
+number of counts including sky in the aperture, the area of the aperture
+in square pixels, and the total number of counts in the aperture excluding
+sky. Mag and merr are the magnitude and error in the magnitude
+in the aperture (see below).
+
+.nf
+        flux = sum - area * msky
+         mag = zmag - 2.5 * log10 (flux) + 2.5 * log10 (itime)
+        merr = 1.0857 * error / flux
+       error = sqrt (flux / epadu + area * stdev**2 +
+               area**2 * stdev**2 / nsky)
+.fi
+
+Pier and perror are photometry error code and accompanying error message.
+
+In interactive mode a radial profile of each measured object is plotted
+in the graphics window if \fIradplots\fR is "yes".
+
+In interactive and batchmode a radial profile plot is written to
+\fIplotfile\fR  if it is defined each time the result of an object
+measurement is written to \fIoutput\fR .
+
+.ih
+ERRORS
+If the object centering was error free then the field cier will be zero.
+Non-zero values of cier flag the following error conditions.
+
+.nf
+	0        # No error
+	101      # The centering box is off image
+	102      # The centering box is partially off the image
+	103      # The S/N ratio is low in the centering box
+	104      # There are two few points for a good fit
+	105      # The x or y center fit is singular
+	106      # The x or y center fit did not converge
+	107      # The x or y center shift is greater than maxshift
+	108      # There is bad data in the centering box
+.fi
+
+If all goes well during the sky fitting process then the error code sier
+will be 0. Non-zero values of sier flag the following error conditions.
+
+.nf
+	0         # No error
+	201       # There are no sky pixels in the sky annulus
+	202       # Sky annulus is partially off the image
+	203       # The histogram of sky pixels has no width
+	204       # The histogram of sky pixels is flat or concave
+	205       # There are too few points for a good sky fit
+	206       # The sky fit is singular
+	207       # The sky fit did not converge
+	208       # The graphics stream is undefined
+	209       # The file of sky values does not exist
+	210       # The sky file is at EOF
+	211       # Cannot read the sky value correctly
+	212       # The best fit parameter are non-physical
+.fi
+
+If no error occurs during the measurement of the magnitudes then pier is
+0. Non-zero values of pier flag the following error conditions.
+
+.nf
+	0        # No error
+	301      # The aperture is off the image
+	302      # The aperture is partially off the image
+	303      # The sky value is undefined
+	305      # There is bad data in the aperture
+.fi
+
+.ih
+EXAMPLES
+
+1. Compute the magnitudes for a few  stars in dev$ypix using the display
+and the image cursor. Setup the task parameters using the interactive
+setup menu defined by the i key command and a radial profile plot.
+
+.nf
+        ap> display dev$ypix 1 fi+
+
+        ... display the image
+
+        ap> wphot dev$ypix
+
+        ... type ? to print an optional help page
+
+        ... move the image cursor to a star
+        ... type i to enter the interactive setup menu
+        ... enter maximum radius in pixels of the radial profile or hit
+            CR to accept the default
+        ... set the fwhmpsf, centering radius, inner and outer sky annuli,
+            photometry apertures, and sigma using the graphics cursor and the
+            stellar radial profile plot
+        ... typing <CR> leaves everything at the default value
+        ... type q to quit the setup menu
+
+        ... type the v key to verify the parameters
+
+        ... type the w key to save the parameters in the parameter files
+
+        ... move the image cursor to the stars of interest and tap
+            the space bar
+
+        ... a one line summary of the fitted parameters will appear on the
+            standard output for each star measured
+
+        ... type q to quit and q again to confirm the quit
+
+        ... the output will appear in ypix.omag.1
+.fi
+
+2. Compute the magnitudes for a few stars in dev$ypix using a contour plot
+and the graphics cursor. This option is only useful for those (now very few)
+users who have access to a graphics terminal but not to an image display
+server. Setup the task parameters using the interactive setup menu defined by
+the i key command as in example 1.
+
+.nf
+        ap> show stdimcur
+
+        ... record the default value of stdimcur
+
+        ap> set stdimcur = stdgraph
+
+        ... define the image cursor to be the graphics cursor
+
+        ap> contour dev$ypix
+
+        ... make a contour plot of dev$ypix
+
+        ap> contour dev$ypix >G ypix.plot1
+
+        ... store the contour plot of dev$ypix in the file ypix.plot1
+
+        ap> wphot dev$ypix display=stdgraph
+
+        ... type ? to get an optional help page
+
+        ... move graphics cursor to a star
+        ... type i to enter the interactive setup menu
+        ... enter maximum radius in pixels of the radial profile or CR
+            to accept the default value
+        ... set the fwhmpsf, centering radius, inner and outer sky annuli,
+            apertures, and sigma using the graphics cursor and the
+            stellar radial profile plot
+        ... typing <CR> leaves everything at the default value
+        ... type q to quit the setup menu
+
+        ... type the v key to verify the critical parameters
+
+        ... type the w key to save the parameters in the parameter files
+
+        ... retype :.read ypix.plot1 to reload the contour plot
+
+        ... move the graphics cursor to the stars of interest and tap
+            the space bar
+
+        ... a one line summary of the fitted parameters will appear on the
+            standard output for each star measured
+
+        ... type q to quit and q again to verify
+
+        ... full output will appear in the text file ypix.omag.2
+
+        ap> set stdimcur = <default>
+
+        ... reset stdimcur to its previous value
+.fi
+
+
+3. Setup and run PHOT interactively on a list of objects temporarily
+overriding the fwhmpsf, sigma, cbox, annulus, dannulus, and apertures
+parameters determined in examples 1 or 2.
+
+.nf
+        ap> daofind dev$ypix fwhmpsf=2.6 sigma=25.0 verify-
+
+        ... make a coordinate list
+
+        ... the output will appear in the text file ypix.coo.1
+
+        ap> wphot dev$ypix cbox=7.0 annulus=12.0 dannulus=5.0 \
+           apertures="3.0,5.0" coords=ypix.coo.1
+
+        ... type ? for optional help
+
+
+        ... move the graphics cursor to the stars and tap space bar
+
+                                or
+
+        ... select stars from the input coordinate list with m / :m #
+            and measure with spbar
+
+        ... measure stars selected from the input coordinate list
+            with n / n #
+
+        ... a one line summary of results will appear on the standard output
+            for each star measured
+
+        ... type q to quit and q again to confirm the quit
+
+        ... the output will appear in ypix.omag.3 ...
+.fi
+
+
+4. Display and measure some stars in an image section and write the output
+coordinates in the coordinate system of the parent image.
+
+.nf
+        ap> display dev$ypix[150:450,150:450] 1
+
+        ... display the image section
+
+        ap> wphot dev$ypix[150:450,150:450] wcsout=tv
+
+        ... move cursor to stars and type spbar
+
+        ... type q to quit and q again to confirm quit
+
+        ... output will appear in ypix.omag.4
+
+        ap> pdump ypix.omag.4 xc,yc yes | tvmark 1 STDIN col=204
+.fi
+
+
+5. Run PHOT in batch mode using the coordinate file and the previously
+saved parameters. Verify the critical parameters.
+
+.nf
+        ap> wphot dev$ypix coords=ypix.coo.1 verify+ inter-
+
+        ... output will appear in ypix.omag.5 ...
+.fi
+
+
+6. Repeat example 5 but assume that the input coordinate are ra and dec
+in degrees and degrees, turn off verification, and submit the task to to
+the background.
+
+.nf
+        ap> display dev$ypix 1
+
+        ap> rimcursor wcs=world > radec.coo
+
+        ... move to selected stars and type any key
+
+        ... type ^Z to quit
+
+        ap> wphot dev$ypix coords=radec.coo wcsin=world verify- inter- &
+
+        ... output will appear in ypix.omag.6
+
+        ap> pdump ypix.omag.6 xc,yc yes | tvmark 1 STDIN col=204
+
+        ... mark the stars on the display
+.fi
+
+
+7. Run PHOT interactively without using the image display.
+
+.nf
+        ap> show stdimcur
+
+        ... record the default value of stdimcur
+
+        ap> set stdimcur = text
+
+        ... set the image cursor to the standard input
+
+        ap> wphot dev$ypix coords=ypix.coo.1
+
+        ... type ? for optional help
+
+        ... type :m 3 to set the initial coordinates to those of the
+            third star in the list
+
+        ... type i to enter the interactive setup menu
+        ... enter the maximum radius in pixels for the radial profile or
+            accept the default with a CR
+        ... type v to enter the default menu
+        ... set the fwhmpsf, centering radius, inner and outer sky annuli,
+            apertures, and sigma using the graphics cursor and the
+            stellar radial profile plot
+        ... typing <CR> after the prompt leaves the parameter at its default
+            value
+        ... type q to quit the setup menu
+
+        ... type r to rewind the coordinate list
+
+        ... type l to measure all the stars in the coordinate list
+
+        ... a one line summary of the answers will appear on the standard
+            output for each star measured
+
+        ... type q to quit followed by q to confirm the quit
+
+        ... full output will appear in the text file ypix.omag.7
+
+        ap> set stdimcur = <default>
+
+        ... reset the value of stdimcur
+.fi
+
+
+8. Use a image cursor command file to drive the PHOT task. The cursor command
+file shown below sets the cbox, annulus, dannulus, and apertures parameters
+computes the centers, sky values, and magnitudes for 3 stars, updates the
+parameter files, and quits the task.
+
+.nf
+        ap> type cmdfile
+        : cbox 9.0
+        : annulus 12.0
+        : dannulus 5.0
+        : apertures 5.0
+        442 410 101 \040
+        349 188 101 \040
+        225 131 101 \040
+        w
+        q
+
+        ap> wphot dev$ypix icommands=cmdfile  verify-
+
+        ... full output will appear in ypix.omag.8
+.fi
+
+
+
+
+.ih
+BUGS
+This task is experimental and requires more work.
+
+It is currently the responsibility of the user to make sure that the
+image displayed in the frame is the same as that specified by the image
+parameter.
+
+Commands which draw to the image display are disabled by default.
+To enable graphics overlay on the image display, set the display
+parameter to "imdr", "imdg", "imdb", or "imdy" to get red, green,
+blue or yellow overlays and set the centerpars mkcenter switch to
+"yes", the fitskypars mksky switch to"yes", or the photpars mkapert
+witch to "yes". It may be necessary to run gflush and to redisplay the image
+to get the overlays position correctly.
+
+
+.ih
+SEE ALSO
+datapars, centerpars, fitskypars, photpars, qphot, phot, polyphot
+.endhelp
diff --git a/noao/digiphot/apphot/findpars.par b/noao/digiphot/apphot/findpars.par
new file mode 100644
index 00000000..f357fd76
--- /dev/null
+++ b/noao/digiphot/apphot/findpars.par
@@ -0,0 +1,12 @@
+# FINDPARS
+
+threshold,r,h,4.0,,,Threshold in sigma for feature detection
+nsigma,r,h,1.5,,,Width of convolution kernel in sigma
+ratio,r,h,1.0,0.0,1.0,Ratio of minor to major axis of Gaussian kernel
+theta,r,h,0.0,0.0,180.0,Position angle of major axis of Gaussian kernel
+sharplo,r,h,.2,,,Lower bound on sharpness for feature detection 
+sharphi,r,h,1.0,,,Upper bound on sharpness for  feature detection
+roundlo,r,h,-1.0,,,Lower bound on roundness for feature detection
+roundhi,r,h,1.0,,,Upper bound on roundness for feature detection
+mkdetections,b,h,no,,,Mark detected stars on the display ?
+mode,s,h,'ql'
diff --git a/noao/digiphot/apphot/fitpsf.par b/noao/digiphot/apphot/fitpsf.par
new file mode 100644
index 00000000..d578683b
--- /dev/null
+++ b/noao/digiphot/apphot/fitpsf.par
@@ -0,0 +1,24 @@
+# FITPSF
+
+image,f,a,,,,"The input image(s)"
+box,r,a,,,,"The fitting box width in scale units"
+coords,f,h,"",,,"The input coordinate list(s) (default: image.coo.?)"
+output,f,h,"default",,,"The output fit file(s) (default: image.psf.?)"
+datapars,pset,h,"",,,"Data dependent parameters"
+function,s,h,"radgauss","|radgauss|elgauss|moments|",,"The fitting function"
+maxiter,i,h,50,,,"The maximum number of fitting iterations"
+nreject,i,h,0,,,"The maximum number of rejection cycles"
+kreject,r,h,3.0,,,The K-sigma rejection limit"
+mkbox,b,h,no,,,"Draw the fitting box on the display ?"
+interactive,b,h,yes,,,"Interactive mode ?"
+icommands,*imcur,h,"",,,"Image cursor: [x y wcs] key [cmd]"
+gcommands,*gcur,h,"",,,"Graphics cursor: [x y wcs] key [cmd]"
+wcsin,s,h,)_.wcsin,,,"The input coordinate system (logical,tv,physical,world)"
+wcsout,s,h,)_.wcsout,,,"The output coordinate system (logical,tv,physical)"
+cache,b,h,)_.cache,,,"Cache the input image pixels in memory ?"
+verify,b,h,)_.verify,,,"Verify critical parameters in non-interactive mode ?"
+update,b,h,)_.update,,,"Update critical parameters in non-interactive mode ?"
+verbose,b,h,)_.verbose,,,"Print messages in non-interactive mode ?"
+graphics,s,h,)_.graphics,,,"Graphics device"
+display,s,h,)_.display,,,"Display device"
+mode,s,h,'ql'
diff --git a/noao/digiphot/apphot/fitpsf/apbfitpsf.x b/noao/digiphot/apphot/fitpsf/apbfitpsf.x
new file mode 100644
index 00000000..9854ab9f
--- /dev/null
+++ b/noao/digiphot/apphot/fitpsf/apbfitpsf.x
@@ -0,0 +1,95 @@
+include <fset.h>
+include "../lib/apphot.h"
+include "../lib/display.h"
+
+# APBFITPSF -- Procedure to fit a functional form to the PSF for a list of
+# objects.
+
+procedure apbfitpsf (ap, im, cl, out, gid, id, ld, interactive)
+
+pointer ap			# pointer to apphot structure
+pointer	im			# pointer to IRAF image
+int	cl			# starlist file descriptor
+int	out			# output file descriptor
+pointer	gid			# image display stream
+int	id			# initial id
+int	ld			# list number
+int	interactive		# interactive mode
+
+int	ier, ild, stdin
+pointer	sp, str
+real	wx, wy
+int	fscan, nscan(), strncmp(), apsffit(), apstati()
+
+begin
+	call smark (sp)
+	call salloc (str, SZ_FNAME, TY_CHAR)
+	call fstats (cl, F_FILENAME, Memc[str], SZ_FNAME)
+
+	# Initialize.
+	ild = ld
+
+	# Print query if input is STDIN.
+	if (strncmp ("STDIN", Memc[str], 5) == 0) {
+	    stdin = YES
+	    call printf ("Type object x and y coordinates (^Z or ^D to end): ")
+	    call flush (STDOUT)
+	} else
+	    stdin = NO
+
+	# Loop over the interesting objects.
+	while (fscan(cl) != EOF) {
+
+	    # Decode the centers.
+	    call gargr (wx)
+	    call gargr (wy)
+	    if (nscan () != 2) {
+		if (stdin == YES) {
+	            call printf (
+		        "Type object x and y coordinates (^Z or ^D to end): ")
+	            call flush (STDOUT)
+	        } 
+		next
+	    }
+
+	    # Transform the input coordinates.
+            switch (apstati(ap,WCSIN)) {
+            case WCS_WORLD, WCS_PHYSICAL:
+                call ap_itol (ap, wx, wy, wx, wy, 1)
+            case WCS_TV:
+                call ap_vtol (im, wx, wy, wx, wy, 1)
+            default:
+                ;
+            }
+
+	    # Store the current cursor coordinates.
+	    call apsetr (ap, CWX, wx)
+	    call apsetr (ap, CWY, wy)
+
+	    # Fit the psf.
+	    ier = apsffit (ap, im, wx, wy)
+
+	    # Output the results.
+	    if (interactive == YES) {
+		call ap_qppsf (ap, ier)
+		if (gid != NULL)
+		    call appfmark (ap, gid, apstati (ap, MKPSFBOX))
+	    }
+	    if (id == 1)
+	        call ap_param (ap, out, "fitpsf")
+	    call ap_ppsf (ap, out, id, ild, ier)
+	    
+	    # Prepare for the next object.
+	    id = id + 1
+	    ild = ild + 1
+	    call apsetr (ap, WX, wx)
+	    call apsetr (ap, WY, wy)
+	    if (stdin == YES) {
+		call printf (
+		    "Type object x and y coordinates (^D or ^Z to end): ")
+		call flush (STDOUT)
+	    } 
+
+	}
+	call sfree (sp)
+end
diff --git a/noao/digiphot/apphot/fitpsf/apfbuf.x b/noao/digiphot/apphot/fitpsf/apfbuf.x
new file mode 100644
index 00000000..428c30cb
--- /dev/null
+++ b/noao/digiphot/apphot/fitpsf/apfbuf.x
@@ -0,0 +1,88 @@
+include <imhdr.h>
+include "../lib/apphotdef.h"
+include "../lib/fitpsfdef.h"
+include "../lib/fitpsf.h"
+
+# APFBUF -- Procedure to fetch the subraster of pixels to be fitted given the
+# pointer to the IRAF image, the coordinates of the center and the apphot
+# structure.
+
+int procedure apfbuf (ap, im, wx, wy)
+
+pointer	ap		# pointer to apphot structure
+pointer	im		# pointer to the IRAF image
+real	wx, wy		# center coordinates
+
+int	ippix
+pointer	psf
+real	ppix
+pointer	ap_psfpix()
+
+begin
+	# Check for 0 sized aperture.
+	psf = AP_PPSF(ap)
+	if (AP_PSFAPERT(psf) <= 0.0)
+	    return (AP_NOPSFAREA)
+
+	# Get the PSF pixels.
+	ppix = max (1.0, AP_PSFAPERT(psf) * AP_SCALE(ap))
+	ippix = 2 * int (ppix) + 1
+	AP_PSFPIX(psf) = ap_psfpix (im, wx, wy, ippix, AP_PXC(psf), AP_PYC(psf),
+	    AP_PNX(psf), AP_PNY(psf))
+	if (AP_PSFPIX(psf) == NULL)
+	    return (AP_NOPSFAREA)
+	else if (AP_PNX(psf) < ippix || AP_PNY(psf) < ippix)
+	    return (AP_PSF_OUTOFBOUNDS)
+	else
+	    return (AP_OK)
+end
+
+
+# AP_PSFPIX -- Procedure to fetch the pixels to be used for centering.
+
+pointer procedure ap_psfpix (im, wx, wy, papert, xc, yc, nx, ny)
+
+pointer	im		# pointer to IRAF image
+real	wx, wy		# center of subraster to be extracted
+int	papert		# width of subraster to be extracted
+real	xc, yc		# center of extracted subraster
+int	nx, ny		# dimensions of extracted subraster
+
+int	ncols, nlines, c1, c2, l1, l2, half_papert
+pointer	buf
+real	xc1, xc2, xl1, xl2
+pointer	imgs2r()
+
+begin
+	# Check for nonsensical input.
+	half_papert = (papert - 1) / 2
+	if (half_papert <= 0)
+	    return (NULL)
+
+	# Test for out of bounds pixels
+	ncols = IM_LEN(im,1)
+	nlines = IM_LEN(im,2)
+	xc1 = wx - half_papert
+	xc2 = wx + half_papert
+	xl1 = wy - half_papert
+	xl2 = wy + half_papert
+	if (xc1 > real (ncols) || xc2 < 1.0 || xl1 > real (nlines) || xl2 < 1.0)
+	    return (NULL)
+
+	# Get column and line limits, dimensions and center of subraster.
+	c1 = max (1.0, min (real (ncols), xc1)) + 0.5
+	c2 = min (real (ncols), max (1.0, xc2)) + 0.5
+	l1 = max (1.0, min (real (nlines), xl1)) + 0.5
+	l2 = min (real (nlines), max (1.0, xl2)) + 0.5
+	nx = c2 - c1 + 1
+	ny = l2 - l1 + 1
+	xc = wx - c1 + 1
+	yc = wy - l1 + 1
+
+	# Get pixels and return.
+	buf = imgs2r (im, c1, c2, l1, l2)
+	if (buf == EOF)
+	    return (NULL)
+	else
+	    return (buf)
+end
diff --git a/noao/digiphot/apphot/fitpsf/apfitpsf.x b/noao/digiphot/apphot/fitpsf/apfitpsf.x
new file mode 100644
index 00000000..94957b6a
--- /dev/null
+++ b/noao/digiphot/apphot/fitpsf/apfitpsf.x
@@ -0,0 +1,344 @@
+include <ctype.h>
+include <gset.h>
+include <imhdr.h>
+include "../lib/apphot.h"
+include "../lib/display.h"
+include "../lib/fitpsf.h"
+
+define	HELPFILE	"apphot$fitpsf/fitpsf.key"
+
+# APFITPSF -- Procedure to fit a functional form to the PSF for a list of
+# objects in interactive mode.
+
+int procedure apfitpsf (ap, im, cl, gd, id, out, stid, interactive, cache)
+
+pointer ap			# pointer to apphot structure
+pointer	im			# pointer to IRAF image
+int	cl			# starlist file descriptor
+pointer	gd			# graphics pointer
+pointer	id			# display pointer
+int	out			# output file descriptor
+int	stid			# output file sequence number
+int	interactive		# interactive mode
+int	cache			# cache the input image pixels
+
+real	wx, wy, xlist, ylist
+pointer	sp, cmd
+int	wcs, key, newimage, newbuf, newfit, newlist, ltid, ier
+int	ip, oid, colonkey, prev_num, req_num, buf_size, req_size, old_size
+int	memstat
+
+real	apstatr()
+int	clgcur(), apgscur(), apsffit(), apsfrefit(), apstati()
+int	apgqverify(), apgtverify(), ctoi(), apnew(), ap_memstat(), sizeof()
+
+define  endswitch_ 99
+
+begin
+	# Initialize.
+	call smark (sp)
+	call salloc (cmd, SZ_LINE, TY_CHAR)
+
+	# Initialize the cursor commands.
+	key = ' '
+	Memc[cmd] = EOS
+
+	# Initialize the fitting commands.
+	newimage = NO
+	newbuf = YES
+	newfit = YES
+	ier = AP_OK
+
+	# Initialize the sequencing.
+	newlist = NO
+	ltid = 0
+
+	# Loop over the cursor commands.
+	while (clgcur ("icommands", wx, wy, wcs, key, Memc[cmd], SZ_LINE) !=
+	    EOF) {
+
+	    # Store the cursor coordinates
+	    call ap_vtol (im, wx, wy, wx, wy, 1)
+	    call apsetr (ap, CWX, wx)
+	    call apsetr (ap, CWY, wy)
+
+	    # Test to see if the cursor moved.
+	    if (apnew (ap, wx, wy, xlist, ylist, newlist) == YES) {
+		newbuf = YES
+		newfit = YES
+	    }
+
+	    # Loop over the cursor commands.
+	    switch (key) {
+
+	    # Quit.
+	    case 'q':
+		if (interactive == YES) {
+		    if (apgqverify ("fitpsf", ap, key) == YES) {
+			call sfree (sp)
+			return (apgtverify (key))
+		    }
+		} else {
+		    call sfree (sp)
+		    return (NO)
+		}
+	    
+
+	    # Print error messages.
+	    case 'e':
+		if (interactive == YES)
+		    call ap_pferrors (ap, ier)
+
+	    # Print the help pages.
+	    case '?':
+		if ((id != NULL) && (id == gd))
+		    call gpagefile (id, HELPFILE, "")
+		else if (interactive == YES)
+		    call pagefile (HELPFILE, "[space=morehelp,q=quit,?=help]")
+
+	    # Rewind the list.
+	    case 'r':
+		if (cl != NULL) {
+		    call seek (cl, BOFL)
+		    ltid = 0
+		} else if (interactive == YES)
+		    call printf ("No coordinate list\n")
+
+	    # Process the fitpsf colon commands.
+	    case ':':
+		for (ip = 1; IS_WHITE(Memc[cmd+ip-1]); ip = ip + 1)
+		    ;
+		colonkey = Memc[cmd+ip-1]
+
+		switch (colonkey) {
+		case 'm', 'n':
+
+		    # Show/set fitpsf parameters.
+		    if (Memc[cmd+ip] != EOS && Memc[cmd+ip] != ' ') {
+		        call apsfcolon (ap, im, cl, out, stid, ltid, Memc[cmd],
+			    newimage, newbuf, newfit)
+			goto endswitch_
+		    }
+
+                    # No coordinate list.
+                    if (cl == NULL) {
+                        if (interactive == YES)
+                            call printf ("No coordinate list\n")
+                        goto endswitch_
+                    }
+
+		    # Get next object from the list.
+		    ip = ip + 1
+		    prev_num = ltid
+		    if (ctoi (Memc[cmd], ip, req_num) <= 0)
+		        req_num = ltid + 1
+
+		    # Fetch the next object from the list.
+		    if (apgscur (cl, id, xlist, ylist, prev_num, req_num,
+			ltid) == EOF) {
+                        if (interactive == YES)
+                            call printf (
+                            "End of coordinate list, use r key to rewind\n")
+                        goto endswitch_
+		    }
+
+                    # Convert the coordinates.
+                    switch (apstati (ap, WCSIN)) {
+                    case WCS_PHYSICAL, WCS_WORLD:
+                        call ap_itol (ap,  xlist, ylist, xlist, ylist, 1)
+                    case WCS_TV:
+                        call ap_vtol (im, xlist, ylist, xlist, ylist, 1)
+                    default:
+                        ;
+                    }
+
+		    # Move to the next object.
+		    newlist = YES
+		    if (colonkey == 'm') {
+			newbuf = YES
+			newfit = YES
+                        goto endswitch_
+		    }
+
+		    # Measure the next object.
+	            ier = apsffit (ap, im, xlist, ylist)
+		    if (id != NULL) {
+		        call appfmark (ap, id, apstati (ap, MKPSFBOX))
+		    	if (id == gd)
+			    call gflush (id)
+		    	else
+			    call gframe (id)
+		    }
+		    if (interactive == YES)
+	                call ap_qppsf (ap, ier)
+		    if (stid == 1)
+		        call ap_param (ap, out, "fitpsf")
+		    call ap_ppsf (ap, out, stid, ltid, ier)
+		    stid = stid + 1
+		    newbuf = NO
+		    newfit = NO
+
+		default:
+		    call apsfcolon (ap, im, cl, out, stid, ltid, Memc[cmd],
+		        newimage, newbuf, newfit)
+		}
+
+		# Reestablish the image viewport and window.
+		if (newimage == YES) {
+		    if ((id != NULL) && (id != gd))
+		        call ap_gswv (id, Memc[cmd], im, 4)
+                    req_size = MEMFUDGE * IM_LEN(im,1) * IM_LEN(im,2) *
+                        sizeof (IM_PIXTYPE(im))
+                    memstat = ap_memstat (cache, req_size, old_size)
+                    if (memstat == YES)
+                        call ap_pcache (im, INDEFI, buf_size)
+		}
+
+		newimage = NO
+
+	    # Plot a centered stellar radial profile.
+	    case 'd':
+		if (interactive == YES) {
+		    call ap_qrad (ap, im, wx, wy, gd)
+		    newbuf = YES
+		    newfit = YES
+		}
+
+	    # Verify the parameters interactively.
+	    case 'v':
+		call ap_pfconfirm (ap, out, stid)
+		newbuf = YES
+		newfit = YES
+
+	    # Interactively set up fitpsf parameters.
+	    case 'i':
+		if (interactive == YES) {
+		    call ap_pfradsetup (ap, im, wx, wy, gd, out, stid)
+		    newbuf = YES
+		    newfit = YES
+		}
+
+	    # Save the parameters.
+	    case 'w':
+		call ap_ppfpars (ap)
+
+	    # Fit the PSF and save the results.
+	    case 'f',  ' ':
+	        if (newbuf == YES)
+	            ier = apsffit (ap, im, wx, wy)
+	        else if (newfit == YES)
+	            ier = apsfrefit (ap, im)
+		if (id != NULL) {
+		    call appfmark (ap, id, apstati (ap, MKPSFBOX))
+		    if (id == gd)
+			call gflush (id)
+		    else
+			call gframe (id)
+		}
+		if (interactive == YES)
+		    call ap_qppsf (ap, ier)
+		newbuf = NO
+		newfit = NO
+
+		if (key == ' ') {
+		    if (stid == 1)
+		        call ap_param (ap, out, "fitpsf")
+		    if (newlist == YES)
+		        call ap_ppsf (ap, out, stid, ltid, ier)
+		    else
+		        call ap_ppsf (ap, out, stid, 0, ier)
+		    stid = stid + 1
+		}
+
+
+	    # Get, measure the next star in the coordinate list.
+	    case 'm', 'n':
+
+                # No coordinate file.
+                if (cl == NULL) {
+                    if (interactive == YES)
+                        call printf ("No coordinate list\n")
+                    goto endswitch_
+                }
+
+		prev_num = ltid
+		req_num = ltid + 1
+		if (apgscur (cl, id, xlist, ylist, prev_num, req_num,
+		    ltid) == EOF) {
+		    if (interactive == YES)
+                        call printf (
+                            "End of coordinate list, use r key to rewind\n")
+                    goto endswitch_
+		}
+
+                # Convert coordinates if necessary.
+                switch (apstati (ap, WCSIN)) {
+                case WCS_PHYSICAL, WCS_WORLD:
+                    call ap_itol (ap,  xlist, ylist, xlist, ylist, 1)
+                case WCS_TV:
+                    call ap_vtol (im, xlist, ylist, xlist, ylist, 1)
+                default:
+                    ;
+                }
+
+		# Move to next object.
+		newlist = YES
+		if (key == 'm') {
+		    newbuf = YES
+		    newfit = YES
+                    goto endswitch_
+		}
+
+		# Measure next object.
+	        ier = apsffit (ap, im, xlist, ylist)
+		if (id != NULL) {
+		    call appfmark (ap, id, apstati (ap, MKPSFBOX))
+		    if (id == gd)
+			call gflush (id)
+		    else
+			call gframe (id)
+		}
+		if (interactive == YES)
+	            call ap_qppsf (ap, ier)
+		if (stid == 1)
+		    call ap_param (ap, out, "fitpsf")
+		call ap_ppsf (ap, out, stid, ltid, ier)
+		stid = stid + 1
+		newbuf = NO
+		newfit = NO
+
+	    # Process the remainder of the coordinate list.
+	    case 'l':
+		if (cl != NULL) {
+		    oid = stid
+		    ltid = ltid + 1
+		    call apbfitpsf (ap, im, cl, out, id, stid, ltid, YES)
+		    ltid = ltid + stid - oid + 1
+		    if (id != NULL) {
+		        if (id == gd)
+			    call gflush (id)
+		        else
+			    call gframe (id)
+		    }
+		} else if (interactive == YES)
+		    call printf ("No coordinate list\n")
+
+	    default:
+		# do nothing
+		call printf ("Unknown keystroke command\n")
+	    }
+
+endswitch_
+            # Setup for the next object by setting the default keystroke
+            # command and storing the old cursor coordinates in the
+            # centering structure.
+
+	    key = ' '
+	    Memc[cmd] = EOS
+	    call apsetr (ap, WX, apstatr (ap, CWX))
+	    call apsetr (ap, WY, apstatr (ap, CWY))
+
+	}
+
+	call sfree (sp)
+end
diff --git a/noao/digiphot/apphot/fitpsf/apgpfpars.x b/noao/digiphot/apphot/fitpsf/apgpfpars.x
new file mode 100644
index 00000000..ed4b93ab
--- /dev/null
+++ b/noao/digiphot/apphot/fitpsf/apgpfpars.x
@@ -0,0 +1,40 @@
+include "../lib/display.h"
+include "../lib/noise.h"
+include "../lib/fitpsf.h"
+
+# AP_GPFPARS -- Procedure to fetch the fitpsf parameters.
+
+procedure ap_gpfpars (ap)
+
+pointer	ap		# pointer to the apphot structure
+
+int	function
+pointer	sp, str
+bool	clgetb()
+int	clgeti(), btoi(), clgwrd()
+real	clgetr()
+
+begin
+	call smark (sp)
+	call salloc (str, SZ_LINE, TY_CHAR)
+
+	# Open the apphot structure.
+	call apsfinit (ap, AP_RADGAUSS, 3.5, 2.0, AP_NPOISSON)
+	call apsetr (ap, PSFAPERT, clgetr ("box") / 2.0)
+
+	# Get the data dependent parameters.
+	call ap_gdapars (ap)
+
+	# Get the rest of the FITPSF fitting parameters.
+	function = clgwrd ("function", Memc[str], SZ_LINE, PSFFUNCS)
+	call apsets (ap, PSFSTRING, Memc[str])
+	call apseti (ap, PSFUNCTION, function)
+	call apseti (ap, PMAXITER, clgeti ("maxiter"))
+	call apseti (ap, PNREJECT, clgeti ("nreject"))
+	call apsetr (ap, PK2, clgetr ("kreject"))
+
+	# Get the plotting parameters.
+	call apseti (ap, MKPSFBOX, btoi (clgetb ("mkbox")))
+
+	call sfree (sp)
+end
diff --git a/noao/digiphot/apphot/fitpsf/appfconfirm.x b/noao/digiphot/apphot/fitpsf/appfconfirm.x
new file mode 100644
index 00000000..30e111b2
--- /dev/null
+++ b/noao/digiphot/apphot/fitpsf/appfconfirm.x
@@ -0,0 +1,58 @@
+include "../lib/apphot.h"
+include "../lib/noise.h"
+include "../lib/fitpsf.h"
+
+# AP_PFCONFIRM -- Procedure to confirm the critical fitpsf parameters.
+
+procedure ap_pfconfirm (ap, out, stid)
+
+pointer	ap		# pointer to the apphot structure
+int	out		# the output file descriptor
+int	stid		# the output file sequence number
+
+pointer	sp, str
+real	fwhmpsf, psfapert, datamin, datamax
+int	apstati()
+real	apstatr(), ap_vfwhmpsf(), ap_vpsfapert()
+real	ap_vdatamin(), ap_vdatamax()
+
+begin
+	call smark (sp)
+	call salloc (str, SZ_FNAME, TY_CHAR)
+
+	call printf ("\n")
+
+	# Confirm the fitting function.
+	call ap_vpfstring (ap, Memc[str], SZ_FNAME)
+
+	# Confirm the fwhmpsf.
+	if (apstati (ap, PSFUNCTION) != AP_MOMENTS)
+	    fwhmpsf = ap_vfwhmpsf (ap)
+	else
+	    fwhmpsf = apstatr (ap, FWHMPSF)
+
+	# Confirm the fitting box.
+	psfapert = 2.0 * ap_vpsfapert (ap)
+
+	# Confirm the good data minimum and maximum values.
+	datamin = ap_vdatamin (ap)
+	datamax = ap_vdatamax (ap)
+
+	call printf ("\n")
+
+	# Update the database file.
+	if (out != NULL && stid > 1) {
+	    call ap_sparam (out, KY_PSFSTRING, Memc[str], UN_PSFMODEL,
+		"psf fitting function")
+	    call ap_rparam (out, KY_FWHMPSF, fwhmpsf, UN_ASCALEUNIT,
+	        "full width half maximum of the psf")
+	    call ap_rparam (out, KY_PSFAPERT, psfapert, UN_PSFSCALEUNIT,
+	        "width of fitting box")
+	    call ap_rparam (out, KY_DATAMIN, datamin, UN_ACOUNTS,
+	        "minimum good data value")
+	    call ap_rparam (out, KY_DATAMAX, datamax, UN_ACOUNTS,
+	        "maximum good data value")
+	}
+
+	call sfree (sp)
+end
diff --git a/noao/digiphot/apphot/fitpsf/appferrors.x b/noao/digiphot/apphot/fitpsf/appferrors.x
new file mode 100644
index 00000000..20ed8820
--- /dev/null
+++ b/noao/digiphot/apphot/fitpsf/appferrors.x
@@ -0,0 +1,26 @@
+include "../lib/fitpsf.h"
+
+# AP_PFERRORS -- Print detailed fitpsf error messages on the standard output.
+
+procedure ap_pferrors (ap, ier)
+
+pointer	ap		# pointer to apphot structure (unused)
+int	ier		# integer error code
+
+begin
+	switch (ier) {
+	case AP_NOPSFAREA:
+	    call printf (
+	        "The psf fitting aperture is outside the image.\n")
+	case AP_PSF_OUTOFBOUNDS:
+	    call printf (
+	        "The psf fitting aperture is partially outside the image.\n")
+	case AP_NPSF_TOO_SMALL:
+	    call printf (
+	        "The number of data points is too few for psf fitting.\n")
+	case AP_PSF_SINGULAR:
+	    call printf ("The psf fitting solution is singular.\n")
+	case AP_PSF_NOCONVERGE:
+	    call printf ("The psf fitting solution did not converge.\n")
+	}
+end
diff --git a/noao/digiphot/apphot/fitpsf/appfradsetup.x b/noao/digiphot/apphot/fitpsf/appfradsetup.x
new file mode 100644
index 00000000..aaae9be6
--- /dev/null
+++ b/noao/digiphot/apphot/fitpsf/appfradsetup.x
@@ -0,0 +1,86 @@
+define	HELPFILE	"apphot$fitpsf/ifitpsf.key"
+
+# AP_PFRADSETUP -- Procedure to set up fitpsf interactively
+
+procedure ap_pfradsetup (ap, im, wx, wy, gd, out, stid)
+
+pointer	ap			# pointer to apphot structure
+pointer	im			# pointer to to the IRAF image
+real	wx, wy			# cursor coordinates
+pointer	gd			# pointer to graphics stream
+int	out			# output file descriptor
+int	stid			# output file sequence number
+
+int	ier, wcs, key
+pointer	sp, cmd
+real	xcenter, ycenter, rmin, rmax, imin, imax, xc, yc, rval
+real	u1, u2, v1, v2, x1, x2, y1, y2
+
+int	apsffit(), clgcur(), ap_showplot()
+real	ap_cfwhmpsf(), ap_cpapert(), ap_cdatamin(), ap_cdatamax()
+
+begin
+	if (gd == NULL)
+	    return
+	call greactivate (gd, 0)
+	call gclear (gd)
+
+	# Save old viewport and window coordinates
+	call ggview (gd, u1, u2, v1, v2)
+	call ggwind (gd, x1, x2, y1, y2)
+
+	# plot the radial profile.
+	if (ap_showplot (ap, im, wx, wy, gd, xcenter, ycenter, rmin, rmax,
+	    imin, imax) == ERR) {
+	    call gdeactivate (gd, 0)
+	    return
+	}
+
+	# Allocate temporary space.
+	call smark (sp)
+	call salloc (cmd, SZ_LINE, TY_CHAR)
+	
+	call printf (
+	"Waiting for setup menu command (?=help, v=default setup, q=quit):\n")
+	while (clgcur ("gcommands", xc, yc, wcs, key, Memc[cmd], SZ_LINE) !=
+	    EOF) {
+
+	switch (key) {
+
+	    case 'q':
+	        break
+	    case '?':
+		call gpagefile (gd, HELPFILE, "")
+	    case 'f':
+	        rval = ap_cfwhmpsf (ap, gd, out, stid, rmin, rmax, imin, imax)
+	    case 'l':
+	        rval = ap_cdatamin (ap, gd, out, stid, rmin, rmax, imin, imax)
+	    case 'u':
+	        rval = ap_cdatamax (ap, gd, out, stid, rmin, rmax, imin, imax)
+	    case 'b':
+		rval = ap_cpapert (ap, gd, out, stid, rmin, rmax, imin, imax)
+	    case 'v':
+		rval = ap_cpapert (ap, gd, out, stid, rmin, rmax, imin, imax)
+	        rval = ap_cfwhmpsf (ap, gd, out, stid, rmin, rmax, imin, imax)
+	    default:
+		call printf ("Unknown or ambiguous keystroke command\007\n")
+	    }
+	    call printf (
+	 "Waiting for setup menu command (?=help, v=default setup, q=quit):\n")
+	}
+
+	# Interactive setup is complete.
+	call printf (
+	    "Interactive setup is complete. Type w to save parameters.\n")
+
+	# Restore old viewport and window coords.
+	call gsview (gd, u1, u2, v1, v2)
+	call gswind (gd, x1, x2, y1, y2)
+
+	call gdeactivate (gd, 0)
+	call sfree (sp)
+
+	# Fit the object.
+	ier = apsffit (ap, im, xcenter, ycenter)
+	call ap_qppsf (ap, ier)
+end
diff --git a/noao/digiphot/apphot/fitpsf/apppfpars.x b/noao/digiphot/apphot/fitpsf/apppfpars.x
new file mode 100644
index 00000000..58f40bcf
--- /dev/null
+++ b/noao/digiphot/apphot/fitpsf/apppfpars.x
@@ -0,0 +1,34 @@
+include "../lib/fitpsf.h"
+include "../lib/display.h"
+
+# AP_PPFPARS -- Procedure to write the fitpsf parameters to a parameter file.
+
+procedure ap_ppfpars (ap)
+
+pointer	ap		# pointer to apphot structure
+
+pointer	sp, str
+bool	itob()
+int	apstati()
+real	apstatr()
+
+begin
+	# Initialize and open psets.
+	call smark (sp)
+	call salloc (str, SZ_LINE, TY_CHAR)
+
+	# Store the psf fitting parameters.
+	call clputr ("box", 2.0 * apstatr (ap, PSFAPERT))
+	call apstats (ap, PSFSTRING, Memc[str], SZ_FNAME)
+	call clpstr ("function", Memc[str])
+	call clputi ("maxiter", apstati (ap, PMAXITER))
+	call clputr ("kreject", apstatr (ap, PK2))
+	call clputi ("nreject", apstati (ap, PNREJECT))
+	call clputb ("mkbox", itob (apstati (ap, MKPSFBOX)))
+
+	# Store the data dependent parameters.
+	call ap_dapars (ap)
+
+	# Closeup.
+	call sfree (sp)
+end
diff --git a/noao/digiphot/apphot/fitpsf/apppsf.x b/noao/digiphot/apphot/fitpsf/apppsf.x
new file mode 100644
index 00000000..c3604c87
--- /dev/null
+++ b/noao/digiphot/apphot/fitpsf/apppsf.x
@@ -0,0 +1,123 @@
+include "../lib/apphotdef.h"
+include "../lib/fitpsfdef.h"
+include "../lib/apphot.h"
+include "../lib/fitpsf.h"
+
+# AP_PPSF -- Procedure to write the results of fitpsf to the output file.
+
+procedure ap_ppsf (ap, fd, id, lid, ier)
+
+pointer	ap	# pointer to apphot structure
+int	fd	# output file descriptor
+int	id	# sequence number of star
+int	lid	# list id of star
+int	ier	# comment string
+
+real	apstatr()
+
+begin
+	# Initialize.
+	if (fd == NULL)
+	    return
+
+	# Print the stars id.
+	call ap_wid (ap, fd, apstatr (ap, OPFXCUR), apstatr (ap, OPFYCUR), id,
+	    lid, '\\')
+
+	# Print the parameters.
+	call ap_wfres (ap, fd, ier)
+end
+
+
+# AP_QPPSF -- Procedure to print the results of fitpsf on the standard output
+# in short form.
+
+procedure ap_qppsf (ap, ier)
+
+pointer	ap	# pointer to apphot structure
+int	ier	# comment string
+
+pointer	sp, imname, psf
+
+begin
+	# Initialize.
+	call smark (sp)
+	call salloc (imname, SZ_FNAME, TY_CHAR)
+	psf = AP_PPSF(ap)
+
+	# Print the parameters on the standard output.
+	call apstats (ap, IMROOT, Memc[imname], SZ_FNAME)
+	switch (AP_PSFUNCTION(psf)) {
+	case AP_RADGAUSS:
+	    call printf (
+	    "%s  %8.2f %8.2f  %6.3f %8g %8g  %s\n") 
+		call pargstr (Memc[imname])
+		call pargr (Memr[AP_PPARS(psf)+1])
+		call pargr (Memr[AP_PPARS(psf)+2])
+		call pargr (Memr[AP_PPARS(psf)+3])
+		call pargr (Memr[AP_PPARS(psf)])
+		call pargr (Memr[AP_PPARS(psf)+4])
+		if (ier != AP_OK)
+		    call pargstr ("err")
+		else
+		    call pargstr ("ok")
+	case AP_ELLGAUSS:
+	    call printf ("%s  %8.2f %8.2f  %6.3f %6.3f  ")
+		call pargstr (Memc[imname])
+		call pargr (Memr[AP_PPARS(psf)+1])
+		call pargr (Memr[AP_PPARS(psf)+2])
+		call pargr (Memr[AP_PPARS(psf)+3])
+		call pargr (Memr[AP_PPARS(psf)+4])
+	    call printf ("%6.1f %8g %8g  %s\n")
+		call pargr (Memr[AP_PPARS(psf)+5])
+		call pargr (Memr[AP_PPARS(psf)])
+		call pargr (Memr[AP_PPARS(psf)+6])
+		if (ier != AP_OK)
+		    call pargstr ("err")
+		else
+		    call pargstr ("ok")
+	case AP_MOMENTS:
+	    call printf ("%s  %8.2f %8.2f  %6.3f %6.3f ")
+		call pargstr (Memc[imname])
+		call pargr (Memr[AP_PPARS(psf)+1])
+		call pargr (Memr[AP_PPARS(psf)+2])
+		call pargr (Memr[AP_PPARS(psf)+3])
+		call pargr (Memr[AP_PPARS(psf)+4])
+	    call printf ("%6.1f  %8g %8g  %s\n")
+		call pargr (Memr[AP_PPARS(psf)+5])
+		call pargr (Memr[AP_PPARS(psf)])
+		call pargr (Memr[AP_PPARS(psf)+6])
+		if (ier != AP_OK)
+		    call pargstr ("err")
+		else
+		    call pargstr ("ok")
+	}
+
+	call sfree (sp)
+end
+
+
+# AP_PFHDR -- Procedure to write the banner for the fitpsf output file.
+
+procedure ap_pfhdr (ap, fd)
+
+pointer	ap		# pointer to the apphot strucuture
+int	fd		# output file descriptor
+
+int	apstati()
+
+begin
+	if (fd == NULL)
+	    return
+
+	switch (apstati (ap, PSFUNCTION)) {
+	case AP_RADGAUSS:
+	    call radhdr (ap, fd)
+	case AP_ELLGAUSS:
+	    call elhdr (ap, fd)
+	case AP_MOMENTS:
+	    call momhdr (ap, fd)
+	default:
+	    ;
+	}
+end
diff --git a/noao/digiphot/apphot/fitpsf/appsfshow.x b/noao/digiphot/apphot/fitpsf/appsfshow.x
new file mode 100644
index 00000000..3317bd22
--- /dev/null
+++ b/noao/digiphot/apphot/fitpsf/appsfshow.x
@@ -0,0 +1,59 @@
+include "../lib/display.h"
+include "../lib/fitpsf.h"
+
+# AP_PSFSHOW -- Procedure to print the fitpsf parameters on the standard output.
+
+procedure ap_psfshow (ap)
+
+pointer	ap		# pointer to the apphot structure
+
+begin
+	call ap_nshow (ap)
+	call printf ("\n")
+	call ap_pfshow (ap)
+end
+
+
+# AP_PFSHOW -- Procedure to print out the fitting parameters on the standard
+# output.
+
+procedure ap_pfshow (ap)
+
+pointer	ap		# pointer to apphot structure
+
+pointer	sp, str
+bool	itob()
+int	apstati()
+real	apstatr()
+
+begin
+	# Print the PSF fitting parameters.
+	call smark (sp)
+	call salloc (str, SZ_LINE, TY_CHAR)
+
+	call printf ("Psf Modelling Parameters\n")
+	call apstats (ap, PSFSTRING, Memc[str], SZ_FNAME)
+	call printf ("    %s = %s\n")
+	    call pargstr (KY_PSFSTRING)
+	    call pargstr (Memc[str])
+
+	call printf ("    %s = %g %s    %s = %d\n")
+	    call pargstr (KY_PSFAPERT)
+	    call pargr (2.0 * apstatr (ap, PSFAPERT))
+	    call pargstr (UN_PSFSCALEUNIT)
+	    call pargstr (KY_PMAXITER)
+	    call pargi (apstati (ap, PMAXITER))
+
+	call printf ("    %s = %g %s    %s = %d\n")
+	    call pargstr (KY_PK2)
+	    call pargr (apstatr (ap, PK2))
+	    call pargstr (UN_PSFSIGMA)
+	    call pargstr (KY_PNREJECT)
+	    call pargi (apstati (ap, PNREJECT))
+
+	call printf ("    %s = %b\n")
+	    call pargstr (KY_MKPSFBOX)
+	    call pargb (itob (apstati (ap, MKPSFBOX)))
+
+	call sfree (sp)
+end
diff --git a/noao/digiphot/apphot/fitpsf/apsfcolon.x b/noao/digiphot/apphot/fitpsf/apsfcolon.x
new file mode 100644
index 00000000..cb4d4521
--- /dev/null
+++ b/noao/digiphot/apphot/fitpsf/apsfcolon.x
@@ -0,0 +1,238 @@
+include "../lib/apphot.h"
+include "../lib/display.h"
+include "../lib/noise.h"
+include "../lib/fitpsf.h"
+
+# APSFCOLON -- Process the  fitpsf task colon commands.
+
+procedure apsfcolon (ap, im, cl, out, stid, ltid, cmdstr, newimage, newbuf,
+	newfit)
+
+pointer	ap		# pointer to the apphot structure
+pointer	im		# pointer to the iraf image
+int	cl		# coordinate file descriptor
+int	out		# output file descriptor
+int	stid		# output file sequence number
+int	ltid		# coord file sequence number
+char	cmdstr		# command string
+int	newimage	# new image ?
+int	newbuf		# new psf buffer ?
+int	newfit		# new psf fit ?
+
+int	junk
+pointer	sp, incmd, outcmd
+int	strdic()
+
+begin
+	call smark (sp)
+	call salloc (incmd, SZ_LINE, TY_CHAR)
+	call salloc (outcmd, SZ_LINE, TY_CHAR)
+
+	# Get the command.
+	call sscan (cmdstr)
+	call gargwrd (Memc[incmd], SZ_LINE)
+	if (Memc[incmd] == EOS) {
+	    call sfree (sp)
+	    return
+	}
+
+	# Process the command.
+	if (strdic (Memc[incmd], Memc[outcmd], SZ_LINE, PSFCMDS) != 0)
+	    call ap_fitcolon (ap, out, stid, cmdstr, newbuf, newfit)
+	else if (strdic (Memc[incmd], Memc[outcmd], SZ_LINE, APCMDS) != 0)
+	    call ap_apcolon (ap, im, cl, out, stid, ltid, cmdstr, newimage,
+	        junk, junk, junk, junk, newbuf, newfit)
+	else if (strdic (Memc[incmd], Memc[outcmd], SZ_LINE, NCMDS) != 0)
+	    call apnscolon (ap, im, out, stid, cmdstr, junk, junk,
+	        junk, junk, newbuf, newfit)
+	else
+	    call ap_pfimcolon (ap, cmdstr)
+
+	call sfree (sp)
+end
+
+
+# AP_FITCOLON -- Procedure to show/set the fitpsf parameters.
+
+procedure ap_fitcolon (ap, out, stid, cmdstr, newbuf, newfit)
+
+pointer	ap		# pointer to the apphot structure
+int	out		# output file descriptor
+int	stid		# output file sequence number
+char	cmdstr		# command string
+int	newbuf		# new psf buffer
+int	newfit		# new psf fit
+
+bool	bval
+int	ncmd, ival, stat
+pointer	sp, cmd, str
+real	rval
+
+bool	itob()
+int	nscan(), strdic(), apstati(), btoi()
+real	apstatr()
+
+begin
+	call smark (sp)
+	call salloc (cmd, SZ_LINE, TY_CHAR)
+	call salloc (str, SZ_FNAME, TY_CHAR)
+
+	# Get the command.
+	call sscan (cmdstr)
+	    call gargwrd (Memc[cmd], SZ_LINE)
+	if (Memc[cmd] == EOS) {
+	    call sfree (sp)
+	    return
+	}
+
+	# Process the command.
+	ncmd = strdic (Memc[cmd], Memc[cmd], SZ_LINE, PSFCMDS)
+	switch (ncmd) {
+	case PFCMD_FUNCTION:
+	    call gargwrd (Memc[cmd], SZ_LINE)
+	    if (nscan() == 1) {
+		call apstats (ap, PSFSTRING, Memc[str], SZ_FNAME)
+		call printf ("%s = %s\n")
+		    call pargstr (KY_PSFSTRING)
+		    call pargstr (Memc[str])
+	    } else {
+		stat = strdic (Memc[cmd], Memc[cmd], SZ_LINE, PSFFUNCS)
+		if (stat > 0) {
+		    call apseti (ap, PSFUNCTION, stat)
+		    call apsets (ap, PSFSTRING, Memc[cmd])
+		    switch (stat) {
+		    case AP_RADGAUSS:
+			call apseti (ap, NPARS, 5)
+		    case AP_ELLGAUSS:
+		        call apseti (ap, NPARS, 7)
+		    case AP_MOMENTS:
+		        call apseti (ap, NPARS, 7)
+		    }
+		    if (stid > 1)
+			call ap_sparam (out, "FUNCTION", Memc[cmd], "model",
+			    "fitting function")
+		    newfit = YES
+		}
+	    }
+	case PFCMD_BOX:
+	    call gargr (rval)
+	    if (nscan() == 1) {
+		call printf ("%s = %g %s\n")
+		    call pargstr (KY_PSFAPERT)
+		    call pargr (2.0 * apstatr (ap, PSFAPERT))
+		    call pargstr (UN_PSFSCALEUNIT)
+	    } else {
+		call apsetr (ap, PSFAPERT, rval / 2.0)
+		if (stid > 1)
+		    call ap_rparam (out, KY_PSFAPERT, rval, UN_PSFSCALEUNIT,
+			"fitting box width")
+		newbuf = YES
+		newfit = YES
+	    }
+	case PFCMD_KREJECT:
+	    call gargr (rval)
+	    if (nscan() == 1) {
+		call printf ("%s = %g %s\n")
+		    call pargstr (KY_PK2)
+		    call pargr (apstatr (ap, PK2))
+		    call pargstr (UN_PSFSIGMA)
+	    } else {
+		call apsetr (ap, PK2, rval)
+		if (stid > 1)
+		    call ap_rparam (out, KY_PK2, rval, UN_PSFSIGMA,
+			"k-sigma rejection criterion")
+		newfit = YES
+	    }
+	case PFCMD_MAXITER:
+	    call gargi (ival)
+	    if (nscan () == 1) {
+		call printf ("%s = %d\n")
+		    call pargstr (KY_PMAXITER)
+		    call pargi (apstati (ap, PMAXITER))
+	    } else {
+		call apseti (ap, PMAXITER, ival)
+		if (stid > 1)
+		    call ap_iparam (out, KY_PMAXITER, ival, UN_PSFNUMBER,
+			"maximum number of iterations")
+		newfit = YES
+	    }
+	case PFCMD_NREJECT:
+	    call gargi (ival)
+	    if (nscan () == 1) {
+		call printf ("%s = %d\n")
+		    call pargstr (KY_PNREJECT)
+		    call pargi (apstati (ap, PNREJECT))
+	    } else {
+		call apseti (ap, PNREJECT, ival)
+		if (stid > 1)
+		    call ap_iparam (out, KY_PNREJECT, ival, UN_PSFNUMBER,
+			"maximum number of rejection cycles")
+		newfit = YES
+	    }
+	case PFCMD_MKBOX:
+	    call gargb (bval)
+	    if (nscan() == 1) {
+		call printf ("%s = %b\n")
+		    call pargstr (KY_MKPSFBOX)
+		    call pargb (itob (apstati (ap, MKPSFBOX)))
+	    } else
+		call apseti (ap, MKPSFBOX, btoi (bval))
+	default:
+	    # do nothing gracefully
+	    call printf ("Unknown or ambiguous colon command\n")
+	}
+
+	call sfree (sp)
+end
+
+
+# AP_PFIMCOLON -- Procedure to process fitpsf commands that are not fitpsf
+# parameters.
+
+procedure ap_pfimcolon (ap, cmdstr)
+
+pointer	ap		# pointer to the apphot structure
+char	cmdstr		# command string
+
+int	ncmd
+pointer	sp, cmd
+int	strdic()
+
+begin
+	# Get the command.
+	call smark (sp)
+	call salloc (cmd, SZ_LINE, TY_CHAR)
+
+	call sscan (cmdstr)
+	    call gargwrd (Memc[cmd], SZ_LINE)
+	if (Memc[cmd] == EOS) {
+	    call sfree (sp)
+	    return
+	}
+
+	# Process the command.
+	ncmd = strdic (Memc[cmd], Memc[cmd], SZ_LINE, MISC1)
+	switch (ncmd) {
+	case ACMD_SHOW:
+	    call gargwrd (Memc[cmd], SZ_LINE)
+	    ncmd = strdic (Memc[cmd], Memc[cmd], SZ_LINE, PFSHOWARGS)
+	    switch (ncmd) {
+	    case PFCMD_DATA:
+		call printf ("\n")
+		call ap_nshow (ap)
+		call printf ("\n")
+	    case PFCMD_FIT:
+		call printf ("\n")
+	        call ap_pfshow (ap)
+		call printf ("\n")
+	    default:
+		call printf ("\n")
+	        call ap_psfshow (ap)
+		call printf ("\n")
+	    }
+	default:
+	    call printf ("Unknown or ambigous colon command\7\n")
+	}
+
+	call sfree (sp)
+end
diff --git a/noao/digiphot/apphot/fitpsf/apsfelgauss.x b/noao/digiphot/apphot/fitpsf/apsfelgauss.x
new file mode 100644
index 00000000..df1a9ef4
--- /dev/null
+++ b/noao/digiphot/apphot/fitpsf/apsfelgauss.x
@@ -0,0 +1,185 @@
+include <math.h>
+include <math/nlfit.h>
+include "../lib/noise.h"
+include "../lib/fitpsf.h"
+
+define	NPARAMETERS	7
+define	TOL		0.001
+
+# APSFELGAUSS -- Procedure to fit an elliptical Gaussian function to the
+# stellar data.
+
+int procedure apsfelgauss (ctrpix, nx, ny, emission, fwhmpsf, datamin,
+	datamax, noise, gain, sigma, maxiter, k2, nreject, par, perr, npar)
+
+real	ctrpix[nx,ny]		# object to be centered
+int	nx, ny			# dimensions of subarray
+int	emission		# emission or absorption object
+real	fwhmpsf			# full width half max of the psf
+real	datamin			# minimum good data value
+real	datamax			# maximum good data value
+int	noise			# noise model
+real	gain			# the gain parameter
+real	sigma			# constant term to noise
+int	maxiter			# maximum number of iterations
+real	k2			# k-sigma rejection criterion
+int	nreject			# maximum number of rejection cycles
+real	par[ARB]		# parameters
+real	perr[ARB]		# errors in parameters
+int	npar			# number of parameters
+
+extern	elgauss, delgauss
+int	i, j, npts, fier, imin,imax
+pointer	sp, x, w, list, zfit, nl, ptr
+real	sumw, dummy, chisqr, locut, hicut, ptemp
+int	locpr(), apreject()
+real	asumr(), apwssqr()
+
+begin
+	# Initialize.
+	npts = nx * ny
+	if (npts < NPARAMETERS)
+	    return (AP_NPSF_TOO_SMALL)
+
+	# Allocate working space.
+	call smark (sp)
+	call salloc (x, 2 * npts, TY_REAL)
+	call salloc (w, npts, TY_REAL)
+	call salloc (zfit, npts, TY_REAL)
+	call salloc (list, NPARAMETERS, TY_INT)
+
+	# Define the active parameters.
+	do i = 1, NPARAMETERS
+	    Memi[list+i-1] = i
+
+	# Set up the varaibles array.
+	ptr = x
+	do j = 1, ny {
+	    do i = 1, nx {
+		Memr[ptr] = i
+		Memr[ptr+1] = j
+		ptr = ptr + 2
+	    }
+	}
+
+	# Set up the weight array.
+	switch (noise) {
+	case AP_NCONSTANT:
+	    call amovkr (1.0, Memr[w], npts)
+	case AP_NPOISSON:
+	    call amaxkr (ctrpix, 0.0, Memr[w], npts)
+	    if (gain > 0.0)
+		call adivkr (Memr[w], gain, Memr[w], npts)
+	    if (! IS_INDEFR(sigma))
+		call aaddkr (Memr[w], sigma ** 2, Memr[w], npts)
+	    call apreciprocal (Memr[w], Memr[w], npts, 1.0)
+	default:
+	    call amovkr (1.0, Memr[w], npts)
+	}
+
+	# Make an initial guess at the fitting parameters.
+	if (emission == YES)
+	    call ap_wlimr (ctrpix, Memr[w], nx * ny, datamin, datamax,
+	        par[7], par[1], imin, imax)
+	else
+	    call ap_wlimr (ctrpix, Memr[w], nx * ny, datamin, datamax,
+	        par[7], par[1], imax, imin)
+	par[1] = par[1] - par[7]
+	if (mod (imax, nx) == 0)
+	    imin = imax / nx
+	else
+	    imin = imax / nx + 1
+	par[3] = imin
+	imin = imax - (imin - 1) * nx
+	par[2] = imin
+	par[4] = (fwhmpsf ** 2 / 4.0)
+	par[5] = (fwhmpsf ** 2 / 4.0)
+	par[6] = 0.0
+
+	# Get the centers and errors.
+	call nlinitr (nl, locpr (elgauss), locpr (delgauss), par, perr,
+	    NPARAMETERS, Memi[list], NPARAMETERS, TOL, maxiter)
+	call nlfitr (nl, Memr[x], ctrpix, Memr[w], npts, 2, WTS_USER, fier)
+
+	# Perform the rejection cycle.
+	if (nreject > 0 && k2 > 0.0) {
+	    do i = 1, nreject {
+		call nlvectorr (nl, Memr[x], Memr[zfit], npts, 2)
+		call asubr (ctrpix, Memr[zfit], Memr[zfit], npts)
+		chisqr = apwssqr (Memr[zfit], Memr[w], npts)
+		sumw = asumr (Memr[w], npts)
+		if (sumw <= 0.0)
+		    break
+		else if (chisqr <= 0.0)
+		    break
+		else
+		    chisqr = sqrt (chisqr / sumw)
+		locut = - k2 * chisqr
+		hicut = k2 * chisqr
+		if (apreject (Memr[zfit], Memr[w], npts, locut, hicut) == 0)
+		    break
+		call nlpgetr (nl, par, npar)
+		call nlfreer (nl)
+		call nlinitr (nl, locpr (elgauss), locpr (delgauss), par,
+		    perr, NPARAMETERS, Memi[list], NPARAMETERS, TOL, maxiter)
+		call nlfitr (nl, Memr[x], ctrpix, Memr[w], npts, 2, WTS_USER,
+		    fier)
+	    }
+	}
+
+	# Fetch the parameters.
+	call nlvectorr (nl, Memr[x], Memr[zfit], npts, 2)
+	call nlpgetr (nl, par, npar)
+	par[4] = sqrt (abs(par[4]))
+	par[5] = sqrt (abs(par[5]))
+
+	# Fetch the errors.
+	call nlerrorsr (nl, ctrpix, Memr[zfit], Memr[w], npts, dummy,
+	    chisqr, perr)
+	perr[4] = sqrt (perr[4])
+	perr[5] = sqrt (perr[5])
+
+	# Compute the mean errors.
+	dummy = 0.0
+	do i = 1, npts {
+	    if (Memr[w+i-1] > 0.0)
+		dummy = dummy + 1.0
+	}
+	dummy = sqrt (dummy)
+	if (dummy > 0.0)
+	    call adivkr (perr, dummy, perr, npar)
+
+	# Transform the parameters.
+	par[6] = mod (RADTODEG(par[6]), 360.0)
+	if (par[6] < 0.0)
+	    par[6] = 360.0 + par[6]
+	if (par[6] > 90.0 && par[6] <= 270.0)
+	    par[6] = par[6] - 180.0
+	else if (par[6] > 270.0 && par[6] <= 360.0)
+	    par[6] = par[6] - 360.0
+	if (par[5] > par[4]) {
+	    if (par[6] > 0.0)
+		par[6] = par[6] - 90.0
+	    else if (par[6] < 0.0)
+		par[6] = par[6] + 90.0
+	    ptemp = par[4]
+	    par[4] = par[5]
+	    par[5] = ptemp
+	}
+	perr[6] = mod (RADTODEG(perr[6]), 360.0)
+
+	call nlfreer (nl)
+
+	call sfree (sp)
+
+	# Return the appropriate error code.
+	if (fier == NO_DEG_FREEDOM) {
+	    return (AP_NPSF_TOO_SMALL)
+	} else if (fier == SINGULAR) {
+	    return (AP_PSF_SINGULAR)
+	} else if (fier == NOT_DONE) {
+	    return (AP_PSF_NOCONVERGE)
+	} else {
+	    return (AP_OK)
+	}
+end
diff --git a/noao/digiphot/apphot/fitpsf/apsffit.x b/noao/digiphot/apphot/fitpsf/apsffit.x
new file mode 100644
index 00000000..2e6d6dbc
--- /dev/null
+++ b/noao/digiphot/apphot/fitpsf/apsffit.x
@@ -0,0 +1,136 @@
+include <mach.h>
+include "../lib/apphotdef.h"
+include "../lib/apphot.h"
+include "../lib/fitpsfdef.h"
+include "../lib/noisedef.h"
+include "../lib/fitpsf.h"
+
+# APSFFIT -- Procedure to fit an analytic function to the PSF.
+
+int procedure apsffit (ap, im, wx, wy)
+
+pointer	ap		# pointer to the apphot structure
+pointer	im		# pointer to the IRAF image
+real	wx, wy		# object coordinates
+
+int	ier, fier
+pointer	psf, nse
+real	datamin, datamax, dmin, dmax, threshold
+int	apfbuf(), apsfradgauss(), apsfelgauss(), apsfmoments()
+
+begin
+	# Initialize.
+	psf = AP_PPSF(ap)
+	nse = AP_NOISE(ap)
+	AP_PFXCUR(psf) = wx
+	AP_PFYCUR(psf) = wy
+	if (IS_INDEFR(wx) || IS_INDEFR(wy)) {
+            AP_OPFXCUR(psf) = INDEFR
+            AP_OPFYCUR(psf) = INDEFR
+	} else {
+            switch (AP_WCSOUT(ap)) {
+            case WCS_WORLD, WCS_PHYSICAL:
+                call ap_ltoo (ap, wx, wy, AP_OPFXCUR(psf), AP_OPFYCUR(psf), 1)
+            case WCS_TV:
+                call ap_ltov (im, wx, wy, AP_OPFXCUR(psf), AP_OPFYCUR(psf), 1)
+            default:
+                AP_OPFXCUR(psf) = wx
+                AP_OPFYCUR(psf) = wy
+            }
+	}
+	call amovkr (INDEFR, Memr[AP_PPARS(psf)], AP_MAXNPARS(psf))
+	call amovkr (INDEFR, Memr[AP_PPERRS(psf)], AP_MAXNPARS(psf))
+
+	# Fetch the buffer of pixels.
+	ier = apfbuf (ap, im, wx, wy)
+	if (ier == AP_NOPSFAREA)
+	    return (AP_NOPSFAREA)
+
+	# Compute the min and max of the data subraster.
+	if (IS_INDEFR(AP_DATAMIN(ap)))
+	    datamin = -MAX_REAL
+	else
+	    datamin = AP_DATAMIN(ap)
+	if (IS_INDEFR(AP_DATAMAX(ap)))
+	    datamax = MAX_REAL
+	else
+	    datamax = AP_DATAMAX(ap)
+
+	switch (AP_PSFUNCTION(psf)) {
+
+	case AP_RADGAUSS:
+
+	    fier = apsfradgauss (Memr[AP_PSFPIX(psf)], AP_PNX(psf), AP_PNY(psf),
+	        AP_POSITIVE(ap), AP_FWHMPSF(ap) * AP_SCALE(ap), datamin,
+		datamax, AP_NOISEFUNCTION(nse), AP_EPADU(nse),
+		AP_READNOISE(nse) / AP_EPADU(nse), AP_PMAXITER(psf),
+		AP_PK2(psf), AP_PNREJECT(psf), Memr[AP_PPARS(psf)],
+		Memr[AP_PPERRS(psf)], AP_PSFNPARS(psf))
+
+	    Memr[AP_PPARS(psf)+1] = Memr[AP_PPARS(psf)+1] + wx - AP_PXC(psf)
+	    Memr[AP_PPARS(psf)+2] = Memr[AP_PPARS(psf)+2] + wy - AP_PYC(psf) 
+
+	case AP_ELLGAUSS:
+
+	    fier = apsfelgauss (Memr[AP_PSFPIX(psf)], AP_PNX(psf), AP_PNY(psf),
+	        AP_POSITIVE(ap), AP_FWHMPSF(ap) * AP_SCALE(ap), datamin,
+		datamax, AP_NOISEFUNCTION(nse), AP_EPADU(nse),
+		AP_READNOISE(nse) / AP_EPADU(nse), AP_PMAXITER(psf),
+		AP_PK2(psf), AP_PNREJECT(psf), Memr[AP_PPARS(psf)],
+		Memr[AP_PPERRS(psf)], AP_PSFNPARS(psf))
+
+	    Memr[AP_PPARS(psf)+1] = Memr[AP_PPARS(psf)+1] + wx - AP_PXC(psf)
+	    Memr[AP_PPARS(psf)+2] = Memr[AP_PPARS(psf)+2] + wy - AP_PYC(psf) 
+
+	case AP_MOMENTS:
+
+	    call alimr (Memr[AP_PSFPIX(psf)], AP_PNX(psf) * AP_PNY(psf),
+	        dmin, dmax)
+	    dmin = max (dmin, datamin)
+	    dmax = min (dmax, datamax)
+	    threshold = 0.0
+
+	    if (AP_POSITIVE(ap) == YES)
+	        fier = apsfmoments (Memr[AP_PSFPIX(psf)], AP_PNX(psf),
+		    AP_PNY(psf), dmin + threshold, dmax,
+		    AP_POSITIVE(ap), Memr[AP_PPARS(psf)], Memr[AP_PPERRS(psf)],
+		    AP_PSFNPARS(psf))
+	    else
+	        fier = apsfmoments (Memr[AP_PSFPIX(psf)], AP_PNX(psf),
+		    AP_PNY(psf), dmax - threshold, dmin,
+		    AP_POSITIVE(ap), Memr[AP_PPARS(psf)],
+		    Memr[AP_PPERRS(psf)], AP_PSFNPARS(psf))
+
+	    Memr[AP_PPARS(psf)+1] = Memr[AP_PPARS(psf)+1] + wx - AP_PXC(psf)
+	    Memr[AP_PPARS(psf)+2] = Memr[AP_PPARS(psf)+2] + wy - AP_PYC(psf) 
+
+	default:
+
+	    # do nothing gracefully
+
+        }
+
+        switch (AP_WCSOUT(ap)) {
+        case WCS_WORLD, WCS_PHYSICAL:
+            call ap_ltoo (ap, Memr[AP_PPARS(psf)+1], Memr[AP_PPARS(psf)+2],
+		Memr[AP_PPARS(psf)+1], Memr[AP_PPARS(psf)+2], 1)
+        case WCS_TV:
+            call ap_ltov (im, Memr[AP_PPARS(psf)+1], Memr[AP_PPARS(psf)+2],
+		Memr[AP_PPARS(psf)+1], Memr[AP_PPARS(psf)+2], 1)
+        default:
+	    ;
+        }
+
+	# Return the appropriate error code.
+	if (fier == AP_OK) {
+	    if (ier == AP_PSF_OUTOFBOUNDS)
+		return (AP_PSF_OUTOFBOUNDS)
+	    else
+		return (AP_OK)
+	} else if (fier == AP_NPSF_TOO_SMALL) {
+	    call amovkr (INDEFR, Memr[AP_PPARS(psf)], AP_PSFNPARS(psf))
+	    call amovkr (INDEFR, Memr[AP_PPERRS(psf)], AP_PSFNPARS(psf))
+	    return (AP_NPSF_TOO_SMALL)
+	} else
+	    return (fier)
+end
diff --git a/noao/digiphot/apphot/fitpsf/apsffree.x b/noao/digiphot/apphot/fitpsf/apsffree.x
new file mode 100644
index 00000000..6bac4607
--- /dev/null
+++ b/noao/digiphot/apphot/fitpsf/apsffree.x
@@ -0,0 +1,52 @@
+include "../lib/apphotdef.h"
+include "../lib/fitpsfdef.h"
+
+# APSFFREE -- Procedure to free the point spread fitting structure.
+
+procedure apsffree (ap)
+
+pointer	ap		# pointer to the apphot structure
+
+begin
+	if (ap == NULL)
+	    return
+	if (AP_NOISE(ap) != NULL)
+	    call ap_noisecls (ap)
+	if (AP_PDISPLAY(ap) != NULL)
+	    call ap_dispcls (ap)
+	if (AP_PPSF(ap) != NULL)
+	    call ap_psfcls (ap)
+	if (AP_IMBUF(ap) != NULL)
+	    call mfree (AP_IMBUF(ap), TY_REAL)
+	if (AP_MW(ap) != NULL)
+	    call mw_close (AP_MW(ap))
+	call mfree (ap, TY_STRUCT)
+end
+
+
+# AP_PSFCLS -- Procedure to close up the point spread fitting function
+# and arrays
+
+procedure ap_psfcls (ap)
+
+pointer ap		# pointer to apphot structure
+
+pointer	psf
+
+begin
+	if (AP_PPSF(ap) == NULL)
+	    return
+	psf = AP_PPSF(ap)
+	#if (AP_PSFPIX(psf) != NULL)
+	    #call mfree (AP_PSFPIX(psf), TY_REAL)
+	if (AP_PSFXPIX(psf) != NULL)
+	    call mfree (AP_PSFXPIX(psf), TY_REAL)
+	if (AP_PSFYPIX(psf) != NULL)
+	    call mfree (AP_PSFYPIX(psf), TY_REAL)
+	if (AP_PPARS(psf) != NULL)
+	    call mfree (AP_PPARS(psf), TY_REAL)
+	if (AP_PPERRS(psf) != NULL)
+	    call mfree (AP_PPERRS(psf), TY_REAL)
+	if (AP_PPSF(ap) != NULL)
+	    call mfree (AP_PPSF(ap), TY_STRUCT)
+end
diff --git a/noao/digiphot/apphot/fitpsf/apsfinit.x b/noao/digiphot/apphot/fitpsf/apsfinit.x
new file mode 100644
index 00000000..19e5a42d
--- /dev/null
+++ b/noao/digiphot/apphot/fitpsf/apsfinit.x
@@ -0,0 +1,94 @@
+include "../lib/apphotdef.h"
+include "../lib/fitpsfdef.h"
+include "../lib/fitpsf.h"
+
+# APSFINIT - Procedure to initialize the point spread modelling structure.
+
+procedure apsfinit (ap, function, rbox, fwhmpsf, noise)
+
+pointer	ap		# pointer to the apphot structure
+int	function	# fitting function
+real	rbox		# fitting radius
+real	fwhmpsf		# full width half max of psf
+int	noise		# noise model
+
+begin
+	# Initialize the image parameters.
+	call malloc (ap, LEN_APSTRUCT, TY_STRUCT)
+
+	# Set up the global apphot package parameters.
+	call ap_defsetup (ap, fwhmpsf)
+
+	# Setup noise model.
+	call ap_noisesetup (ap, noise)
+
+	# Set up the point spread fitting function.
+	call ap_psfsetup (ap, function, rbox)
+
+	# Set display options.
+	call ap_dispsetup (ap)
+
+	# Set remaining unused structure pointers to NULL.
+	AP_PCENTER(ap) = NULL
+	AP_PSKY(ap) = NULL
+	AP_PPHOT(ap) = NULL
+	AP_POLY(ap) = NULL
+	AP_RPROF(ap) = NULL
+end
+
+
+# AP_PSFSETUP -- Procedure to define the PSF fitting parameters.
+
+procedure ap_psfsetup (ap, function, rbox)
+
+pointer	ap 		# pointer to apphot structure
+int	function	# fitting function
+real	rbox		# fitting aperture
+
+pointer	psf
+
+begin
+	call malloc (AP_PPSF(ap), LEN_PSFSTRUCT, TY_STRUCT)
+	psf = AP_PPSF(ap)
+
+	# Set PSF fitting function.
+	AP_PSFUNCTION(psf) = function
+	switch (function) {
+	case AP_RADGAUSS:
+	    call strcpy ("radgauss", AP_PSFSTRING(psf), SZ_FNAME)
+	case AP_ELLGAUSS:
+	    call strcpy ("elgauss", AP_PSFSTRING(psf), SZ_FNAME)
+	case AP_MOMENTS:
+	    call strcpy ("moments", AP_PSFSTRING(psf), SZ_FNAME)
+	default:
+	    call strcpy ("radgauss", AP_PSFSTRING(psf), SZ_FNAME)
+	}
+	AP_PFXCUR(psf) = INDEFR
+	AP_PFYCUR(psf) = INDEFR
+	switch (function) {
+	case AP_RADGAUSS:
+	    AP_PSFNPARS(psf) = 5
+	case AP_ELLGAUSS:
+	    AP_PSFNPARS(psf) = 7
+	case AP_MOMENTS:
+	    AP_PSFNPARS(psf) = 7
+	}
+
+	# Set remaining PSF parameters.
+	AP_PSFAPERT(psf) = rbox
+	AP_MAXNPARS(psf) = DEF_MAXNPARS
+	AP_PK2(psf) = DEF_PK2
+	AP_PMAXITER(psf) = DEF_PMAXITER
+	AP_PNREJECT(psf) = DEF_PNREJECT
+
+	# Initialize buffers.
+	AP_LENPSFBUF(psf) = 0
+	AP_NPSFPIX(psf) = 0
+	AP_PSFPIX(psf) = NULL
+	AP_PSFXPIX(psf) = NULL
+	AP_PSFYPIX(psf) = NULL
+
+	# Allocate space for computed parameters.
+	call calloc (AP_PPARS(psf), AP_MAXNPARS(psf), TY_REAL)
+	call calloc (AP_PPERRS(psf), AP_MAXNPARS(psf), TY_REAL)
+end
diff --git a/noao/digiphot/apphot/fitpsf/apsfmoments.x b/noao/digiphot/apphot/fitpsf/apsfmoments.x
new file mode 100644
index 00000000..ddae00f2
--- /dev/null
+++ b/noao/digiphot/apphot/fitpsf/apsfmoments.x
@@ -0,0 +1,106 @@
+include <math.h>
+include "../lib/fitpsf.h"
+
+define	NPARAMETERS	7
+
+# APSFMOMENTS -- Procedure to compute the 0, 1st and second moments of an 
+# image and estimate the x,y center, the ellipticity and the position angle.
+
+int procedure apsfmoments (ctrpix, nx, ny, lthreshold, uthreshold, positive,
+	par, perr, npar)
+
+real	ctrpix[nx, ny]		# object to be centered
+int	nx, ny			# dimensions of subarray
+real	lthreshold		# lower threshold for moment computation
+real	uthreshold		# upper threshold for moment computation
+int	positive		# emission feature
+real	par[ARB]		# parameters
+real	perr[ARB]		# errors in parameters
+int	npar			# number of parameters
+
+int	i, j
+real	temp, sumi, sumxi, sumyi, sumx2i, sumy2i, sumxyi, r2, varx, vary, varxy
+bool	fp_equalr()
+
+begin
+	# Initialize the sums.
+	sumi = 0.0
+	sumxi = 0.0
+	sumyi = 0.0
+	sumxyi = 0.0
+	sumx2i = 0.0
+	sumy2i = 0.0
+
+	# Accumulate the moments.
+	if (positive == YES) {
+	    do j = 1, ny {
+	        do i = 1, nx {
+		    if (ctrpix[i,j] > uthreshold)
+			next
+		    temp = ctrpix[i,j] - lthreshold
+		    if (temp <= 0.0)
+		        next
+		    sumi = sumi + temp
+		    sumxi = sumxi + i * temp
+		    sumyi = sumyi + j * temp
+		    sumxyi = sumxyi + i * j * temp
+		    sumx2i = sumx2i + i * i * temp
+		    sumy2i = sumy2i + j * j * temp
+	        }
+	    }
+	} else {
+	    do j = 1, ny {
+	        do i = 1, nx {
+		    if (ctrpix[i,j] < uthreshold)
+			next
+		    temp = lthreshold - ctrpix[i,j]
+		    if (temp <= 0.0)
+		        next
+		    sumi = sumi + temp
+		    sumxi = sumxi + i * temp
+		    sumyi = sumyi + j * temp
+		    sumxyi = sumxyi + i * j * temp
+		    sumx2i = sumx2i + i * i * temp
+		    sumy2i = sumy2i + j * j * temp
+	        }
+	    }
+	}
+
+	# Compute the parameters.
+	if (fp_equalr (sumi, 0.0)) {
+	    par[1] = 0.0
+	    par[2] = (1 + nx) / 2.0
+	    par[3] = (1 + ny) / 2.0
+	    par[4] = 0.0
+	    par[5] = 0.0
+	    par[6] = 0.0
+	    par[7] = lthreshold
+	} else {
+	    par[1] = sumi
+	    par[2] = sumxi / sumi
+	    par[3] = sumyi / sumi
+	    varx = max (0.0, sumx2i / sumi - par[2] ** 2)
+	    vary = max (0.0, sumy2i / sumi - par[3] ** 2)
+	    r2 = varx + vary
+	    if (r2 <= 0.0) {
+		par[4] = 0.0
+		par[5] = 0.0
+		par[6] = 0.0
+	    } else {
+	        par[4] = sqrt (r2)
+	        varxy = sumxyi / sumi - par[2] * par[3]
+	        par[5] = sqrt ((varx - vary) ** 2 + 4.0 * varxy ** 2) / r2
+		par[6] = (0.5 * r2 * (1.0 + par[5]) - vary)
+		if (fp_equalr (par[6], 0.0))
+		    par[6] = 90.0
+		else
+		    par[6] = RADTODEG (atan (varxy / par[6]))
+	    }
+	    par[7] = lthreshold
+	}
+
+	# Compute the errors.
+	npar = NPARAMETERS
+	call amovkr (0.0, perr, NPARAMETERS)
+	return (AP_OK)
+end
diff --git a/noao/digiphot/apphot/fitpsf/apsfradgauss.x b/noao/digiphot/apphot/fitpsf/apsfradgauss.x
new file mode 100644
index 00000000..0b4a93c6
--- /dev/null
+++ b/noao/digiphot/apphot/fitpsf/apsfradgauss.x
@@ -0,0 +1,183 @@
+include <math/nlfit.h>
+include "../lib/noise.h"
+include "../lib/fitpsf.h"
+
+define	NPARAMETERS	5
+define	TOL		0.001
+
+# APSFRADGAUSS -- Fit a radial Gaussian function to the data.
+
+int procedure apsfradgauss (ctrpix, nx, ny, emission, fwhmpsf, datamin,
+	datamax, noise, gain, sigma, maxiter, k2, nreject, par, perr, npar)
+
+real	ctrpix[nx, ny]		# object to be centered
+int	nx, ny			# dimensions of subarray
+int	emission		# emission or absorption version
+real	fwhmpsf			# full width half max of the psf
+real	datamin			# minimum good data value
+real	datamax			# maximum good data value
+int	noise			# noise model to be used
+real	gain			# the gain in the data
+real	sigma			# sigma of constant noise term
+int	maxiter			# maximum number of iterations
+real	k2			# k-sigma rejection criterion
+int	nreject			# maximum number of rejection cycles
+real	par[ARB]		# parameters
+real	perr[ARB]		# errors in parameters
+int	npar			# number of parameters
+
+extern	gaussr, dgaussr
+int	i, j, npts, list, imin, imax, fier
+pointer	sp, x, w, zfit, nl, ptr
+real	sumw, dummy, chisqr, locut, hicut
+int	locpr(), apreject()
+real	asumr(), apwssqr()
+
+begin
+	# Initialize.
+	npts = nx * ny
+	if (npts < NPARAMETERS)
+	    return (AP_NPSF_TOO_SMALL)
+
+	call smark (sp)
+	call salloc (x, 2 * npts, TY_REAL)
+	call salloc (w, npts, TY_REAL)
+	call salloc (zfit, npts, TY_REAL)
+	call salloc (list, NPARAMETERS, TY_INT)
+
+	# Define the active parameters.
+	do i = 1, NPARAMETERS
+	    Memi[list+i-1] = i
+
+	# Set variables array.
+	ptr = x
+	do j = 1, ny {
+	    do i = 1, nx {
+		Memr[ptr] = i
+		Memr[ptr+1] = j
+		ptr = ptr + 2
+	    }
+	}
+
+	# Define the weight array.
+	switch (noise) {
+	case AP_NCONSTANT:
+	    call amovkr (1.0, Memr[w], npts)
+	case AP_NPOISSON:
+	    call amaxkr (ctrpix, 0.0, Memr[w], npts)
+	    if (gain  > 0.0)
+		call adivkr (Memr[w], gain, Memr[w], npts)
+	    if (! IS_INDEFR(sigma))
+	        call aaddkr (Memr[w], sigma ** 2, Memr[w], npts)
+	    call apreciprocal (Memr[w], Memr[w], npts, 1.0)
+	default:
+	    call amovkr (1.0, Memr[w], npts)
+	}
+
+	# Make an initial guess at the parameters.
+	if (emission == YES)
+	    call ap_wlimr (ctrpix, Memr[w], npts, datamin, datamax,
+	        par[5], par[1], imin, imax)
+	else
+	    call ap_wlimr (ctrpix, Memr[w], npts, datamin, datamax,
+	        par[1], par[5], imax, imin)
+	par[1] = par[1] - par[5]
+	if (mod (imax, nx) == 0)
+	    imin = imax / nx
+	else
+	    imin = imax / nx + 1
+	par[3] = imin
+	imin = imax - (imin - 1) * nx
+	par[2] = imin
+	par[4] = (fwhmpsf ** 2 / 4.0)
+
+	# Fit the function and the errors.
+	call nlinitr (nl, locpr (gaussr), locpr (dgaussr), par, perr,
+	    NPARAMETERS, Memi[list], NPARAMETERS, TOL, maxiter)
+	call nlfitr (nl, Memr[x], ctrpix, Memr[w], npts, 2, WTS_USER, fier)
+
+	# Perform the rejection cycle.
+	if ((nreject > 0) && (k2 > 0.0)) {
+	    do i = 1, nreject {
+		call nlvectorr (nl, Memr[x], Memr[zfit], npts, 2)
+		call asubr (ctrpix, Memr[zfit], Memr[zfit], npts)
+		chisqr = apwssqr (Memr[zfit], Memr[w], npts)
+		sumw = asumr (Memr[w], npts)
+		if (sumw <= 0.0)
+		    break
+		else if (chisqr <= 0.0)
+		    break
+		else
+		    chisqr = sqrt (chisqr / sumw)
+		locut = - k2 * chisqr
+		hicut = k2 * chisqr
+		if (apreject (Memr[zfit], Memr[w], npts, locut, hicut) == 0) 
+		    break
+		call nlpgetr (nl, par, npar)
+		call nlfreer (nl)
+		call nlinitr (nl, locpr (gaussr), locpr (dgaussr), par, perr,
+		    NPARAMETERS, Memi[list], NPARAMETERS, TOL, maxiter)
+		call nlfitr (nl, Memr[x], ctrpix, Memr[w], npts, 2, WTS_USER,
+		    fier)
+	    }
+	}
+
+	# Get the parameters.
+	call nlpgetr (nl, par, npar)
+	par[4] = sqrt (abs(par[4]))
+
+	# Get the errors.
+	call nlvectorr (nl, Memr[x], Memr[zfit], npts, 2)
+	call nlerrorsr (nl, ctrpix, Memr[zfit], Memr[w], npts, dummy,
+	    chisqr, perr)
+	perr[4] = sqrt (abs(perr[4]))
+
+	# Compute the mean errors in the parameters.
+	dummy = 0.0
+	do i = 1, npts {
+	    if (Memr[w+i-1] > 0.0)
+		dummy = dummy + 1.0
+	}
+	dummy = sqrt (dummy)
+	if (dummy > 0.0)
+	    call adivkr (perr, dummy, perr, npar)
+
+	call nlfreer (nl)
+
+	call sfree (sp)
+
+	# Return the appropriate error code.
+	if (fier == NO_DEG_FREEDOM) {
+	    return (AP_NPSF_TOO_SMALL)
+	} else if (fier == SINGULAR) {
+	    return (AP_PSF_SINGULAR)
+	} else if (fier == NOT_DONE) {
+	    return (AP_PSF_NOCONVERGE)
+	} else {
+	    return (AP_OK)
+	}
+end
+
+
+# APREJECT -- Reject points outside of the specified intensity limits by
+# setting their weights to zero.
+
+int procedure apreject (pix, w, npts, locut, hicut)
+
+real	pix[ARB]		# data
+real	w[ARB]			# weights
+int	npts			# number of data points
+real	locut, hicut		# data limits
+
+int	i, nreject
+
+begin
+	nreject = 0
+	do i = 1, npts {
+	    if ((pix[i] < locut || pix[i] > hicut) && w[i] > 0.0) {
+		w[i] = 0.0
+		nreject = nreject + 1
+	    }
+	}
+	return (nreject)
+end
diff --git a/noao/digiphot/apphot/fitpsf/apsfrefit.x b/noao/digiphot/apphot/fitpsf/apsfrefit.x
new file mode 100644
index 00000000..a1b950fa
--- /dev/null
+++ b/noao/digiphot/apphot/fitpsf/apsfrefit.x
@@ -0,0 +1,113 @@
+include <mach.h>
+include "../lib/apphotdef.h"
+include "../lib/apphot.h"
+include "../lib/fitpsfdef.h"
+include "../lib/fitpsf.h"
+include "../lib/noisedef.h"
+
+# APSFREFIT -- Procedure to fit a function to the data already in the
+# data buffers.
+
+int procedure apsfrefit (ap, im)
+
+pointer	ap		# pointer to the apphot structure
+pointer	im		# the input image descriptor
+
+int	ier
+pointer	psf, nse
+int	apsfradgauss(), apsfelgauss(), apsfmoments()
+real	datamin, datamax, dmin, dmax, threshold
+
+begin
+	psf = AP_PPSF(ap)
+	nse = AP_NOISE(ap)
+	call amovkr (INDEFR, Memr[AP_PPARS(psf)], AP_MAXNPARS(psf))
+	call amovkr (INDEFR, Memr[AP_PPERRS(psf)], AP_MAXNPARS(psf))
+
+	# Compute the minimum and maximum good data value.
+	if (IS_INDEFR(AP_DATAMIN(ap)))
+	    datamin = -MAX_REAL
+	else
+	    datamin = AP_DATAMIN(ap)
+	if (IS_INDEFR(AP_DATAMAX(ap)))
+	    datamax = MAX_REAL
+	else
+	    datamax = AP_DATAMAX(ap)
+
+	switch (AP_PSFUNCTION(psf)) {
+
+	case AP_RADGAUSS:
+
+	    ier = apsfradgauss (Memr[AP_PSFPIX(psf)], AP_PNX(psf), AP_PNY(psf),
+		AP_POSITIVE(ap), AP_FWHMPSF(ap) * AP_SCALE(ap), datamin,
+		datamax, AP_NOISEFUNCTION(nse), AP_EPADU(nse),
+		AP_READNOISE(nse) / AP_EPADU(nse), AP_PMAXITER(psf),
+		AP_PK2(psf), AP_PNREJECT(psf), Memr[AP_PPARS(psf)],
+		Memr[AP_PPERRS(psf)], AP_PSFNPARS(psf))
+
+	    Memr[AP_PPARS(psf)+1] = Memr[AP_PPARS(psf)+1] + AP_PFXCUR(psf) -
+		AP_PXC(psf)
+	    Memr[AP_PPARS(psf)+2] = Memr[AP_PPARS(psf)+2] + AP_PFYCUR(psf) -
+		AP_PYC(psf)
+
+	case AP_ELLGAUSS:
+
+	    ier = apsfelgauss (Memr[AP_PSFPIX(psf)], AP_PNX(psf), AP_PNY(psf),
+		AP_POSITIVE(ap), AP_FWHMPSF(ap) * AP_SCALE(ap), datamin,
+		datamax, AP_NOISEFUNCTION(nse), AP_EPADU(nse),
+		AP_READNOISE(nse) / AP_EPADU(nse), AP_PMAXITER(psf),
+		AP_PK2(psf), AP_PNREJECT(psf), Memr[AP_PPARS(psf)],
+		Memr[AP_PPERRS(psf)], AP_PSFNPARS(psf))
+
+	    Memr[AP_PPARS(psf)+1] = Memr[AP_PPARS(psf)+1] + AP_PFXCUR(psf) -
+		AP_PXC(psf)
+	    Memr[AP_PPARS(psf)+2] = Memr[AP_PPARS(psf)+2] + AP_PFYCUR(psf) -
+		AP_PYC(psf)
+
+	case AP_MOMENTS:
+
+	    call alimr (Memr[AP_PSFPIX(psf)], AP_PNX(psf) * AP_PNY(psf),
+		dmin, dmax)
+	    dmin = max (dmin, datamin)
+	    dmax = min (dmax, datamax)
+	    threshold = 0.0
+
+	    if (AP_POSITIVE(ap) == YES)
+	        ier = apsfmoments (Memr[AP_PSFPIX(psf)], AP_PNX(psf),
+		    AP_PNY(psf), dmin + threshold, dmax,
+		    AP_POSITIVE(ap), Memr[AP_PPARS(psf)],
+		    Memr[AP_PPERRS(psf)], AP_PSFNPARS(psf))
+	    else 
+	        ier = apsfmoments (Memr[AP_PSFPIX(psf)], AP_PNX(psf),
+		    AP_PNY(psf), dmax + threshold, dmin,
+		    AP_POSITIVE(ap), Memr[AP_PPARS(psf)],
+		    Memr[AP_PPERRS(psf)], AP_PSFNPARS(psf))
+
+	    Memr[AP_PPARS(psf)+1] = Memr[AP_PPARS(psf)+1] + AP_PFXCUR(psf) -
+		AP_PXC(psf)
+	    Memr[AP_PPARS(psf)+2] = Memr[AP_PPARS(psf)+2] + AP_PFYCUR(psf) -
+		AP_PYC(psf)
+
+	default:
+
+	    # do nothing gracefully
+        }
+
+        switch (AP_WCSOUT(ap)) {
+        case WCS_WORLD, WCS_PHYSICAL:
+            call ap_ltoo (ap, Memr[AP_PPARS(psf)+1], Memr[AP_PPARS(psf)+2],
+                Memr[AP_PPARS(psf)+1], Memr[AP_PPARS(psf)+2], 1)
+        case WCS_TV:
+            call ap_ltov (im, Memr[AP_PPARS(psf)+1], Memr[AP_PPARS(psf)+2],
+                Memr[AP_PPARS(psf)+1], Memr[AP_PPARS(psf)+2], 1)
+        default:
+            ;
+        }
+
+	if (ier == AP_NPSF_TOO_SMALL) {
+	    call amovkr (INDEFR, Memr[AP_PPARS(psf)], AP_PSFNPARS(psf))
+	    call amovkr (INDEFR, Memr[AP_PPERRS(psf)], AP_PSFNPARS(psf))
+	}
+
+	return (ier)
+end
diff --git a/noao/digiphot/apphot/fitpsf/fitpsf.key b/noao/digiphot/apphot/fitpsf/fitpsf.key
new file mode 100644
index 00000000..f7ab725e
--- /dev/null
+++ b/noao/digiphot/apphot/fitpsf/fitpsf.key
@@ -0,0 +1,73 @@
+	       Interactive Keystroke Commands
+
+?	Print help
+:	Colon commands
+v	Verify the critical parameters
+w	Save the current parameters
+d	Plot radial profile of current star 
+i	Interactively set parameters using current star
+f	Fit current star
+spbar	Fit current star, output results
+m	Move to next star in coordinate list
+n	Fit next star in coordinate list, output results
+l	Fit remaining stars in coordinate list, output results
+e	Print error messages
+r	Rewind the coordinate list
+q	Exit task 
+
+
+
+                 Colon Commands
+
+:show	[data/fit]	List the parameters
+:m [n]	Move to next [nth] star in coordinate list
+:n [n]	Fit next [nth] star in coordinate list, output results
+
+
+		Colon Parameter Editing Commands
+
+# Image and file name parameters
+
+:image		[string]	Image name
+:coords		[string]	Coordinate file name
+:output		[string]	Output file name
+
+# Data dependent parameters
+
+:scale		[value]		Image scale (units per pixel)
+:fwhmpsf	[value]		Scale factor (scale units)		
+:emission	[y/n]		Emission feature (y), absorption (n)
+:sigma		[value]		Standard deviation of sky (counts)
+:datamin	[value]		Minimum good data value (counts)
+:datamax	[value]		Maximum good data value (counts)
+
+# Noise description parameters
+
+:noise		[string]	Noise model (constant|poisson)
+:gain		[string]	Gain image header keyword
+:ccdread	[string]	Readout noise image header keyword
+:epadu		[value]		Gain (electrons  per adu)
+:readnoise	[value]		Readnoise (electrons)
+
+# Observation parameters
+
+:exposure	[string]	Exposure time image header keyword
+:airmass	[string]	Airmass image header keyword
+:filter		[string]	Filter image header keyword
+:obstime	[string]        Time of observation image header keyword
+:itime		[value]		Exposure time (time units)
+:xairmass	[value]		Airmass value (number)
+:ifilter	[string]	Filter id string
+:otime		[string]	Time of observation (time units)
+
+# Fitting parameters
+
+:function	[string]	PSF model (radgauss|elgauss|moments)
+:box		[value]		Width of the fitting box (scale units)
+:maxiter	[value]		Maximum number of iterations
+:nreject	[value]		Maximum number of rejection cycles
+:kreject	[value]		Rejection limit (sigma)
+
+# Plotting and marking functions
+
+:mkbox		[y/n]		Mark the fitting box on the display
diff --git a/noao/digiphot/apphot/fitpsf/ifitpsf.key b/noao/digiphot/apphot/fitpsf/ifitpsf.key
new file mode 100644
index 00000000..9bbb4ba9
--- /dev/null
+++ b/noao/digiphot/apphot/fitpsf/ifitpsf.key
@@ -0,0 +1,10 @@
+                    Interactive Fitpsf Setup Menu
+
+	v	Mark and verify the critical fitpsf parameters (f,s,b)
+
+	f	Mark and verify the full-width half-maximum of the psf
+	s	Mark and verify the standard deviation of the background
+	l	Mark and verify the minimum good data value
+	u	Mark and verify the maximum good data value
+
+	b	Mark and verify the half-width of the fitting box
diff --git a/noao/digiphot/apphot/fitpsf/mkpkg b/noao/digiphot/apphot/fitpsf/mkpkg
new file mode 100644
index 00000000..8e8efb12
--- /dev/null
+++ b/noao/digiphot/apphot/fitpsf/mkpkg
@@ -0,0 +1,44 @@
+# FITPSF Task Routines
+
+$checkout libpkg.a ".."
+$update libpkg.a
+$checkin libpkg.a ".."
+$exit
+
+libpkg.a:
+	apbfitpsf.x	<fset.h>		../lib/apphot.h         \
+			../lib/display.h
+	apfbuf.x	<imhdr.h>		../lib/apphotdef.h	\
+			../lib/fitpsfdef.h	 ../lib/fitpsf.h
+	apfitpsf.x	<ctype.h>		<gset.h>		\
+			../lib/apphot.h		../lib/display.h	\
+			../lib/fitpsf.h		<imhdr.h>
+	apppfpars.x	../lib/display.h        ../lib/fitpsf.h
+	apgpfpars.x	../lib/display.h	../lib/fitpsf.h         \
+			../lib/noise.h
+	appfconfirm.x	../lib/apphot.h		../lib/noise.h          \
+			../lib/fitpsf.h
+	appferrors.x	../lib/fitpsf.h
+	apppsf.x	../lib/apphotdef.h	../lib/fitpsfdef.h	\
+			../lib/fitpsf.h		../lib/apphot.h
+	appsfshow.x	../lib/display.h	../lib/fitpsf.h
+	appfradsetup.x
+	apsfcolon.x	../lib/display.h	../lib/fitpsf.h         \
+			../lib/apphot.h	        ../lib/noise.h
+	apsfelgauss.x	<math.h>		../lib/fitpsf.h         \
+			<math/nlfit.h>		../lib/noise.h
+	apsffree.x	../lib/apphotdef.h	../lib/fitpsfdef.h
+	apsfinit.x	../lib/apphotdef.h	../lib/fitpsfdef.h	\
+			../lib/fitpsf.h
+	apsffit.x	../lib/apphotdef.h	../lib/fitpsfdef.h	\
+			../lib/noisedef.h	../lib/fitpsf.h         \
+			../lib/apphot.h          <mach.h>
+	apsfmoments.x	<math.h>		../lib/fitpsf.h
+	apsfradgauss.x  ../lib/fitpsf.h		<math/nlfit.h>   	\
+			../lib/noise.h
+	apsfrefit.x	../lib/apphotdef.h	../lib/fitpsfdef.h	\
+			../lib/fitpsf.h		../lib/noisedef.h       \
+			../lib/apphot.h         <mach.h>
+	t_fitpsf.x	<fset.h>		<gset.h>		\
+			../lib/apphot.h		<imhdr.h>
+	;
diff --git a/noao/digiphot/apphot/fitpsf/t_fitpsf.x b/noao/digiphot/apphot/fitpsf/t_fitpsf.x
new file mode 100644
index 00000000..28345a09
--- /dev/null
+++ b/noao/digiphot/apphot/fitpsf/t_fitpsf.x
@@ -0,0 +1,288 @@
+include <gset.h>
+include <fset.h>
+include <imhdr.h>
+include "../lib/apphot.h"
+
+# T_FITPSF -- Procedure to fit an analytic function to the PSF for a list
+# of objects in a list of images.
+
+procedure t_fitpsf ()
+
+pointer image		# pointer to the name of the image
+pointer output		# pointer to the output file name
+pointer coords		# pointer to the coordinate file
+pointer graphics	# pointer to the graphics display device
+pointer display		# pointer to the display device
+int	interactive	# mode of use
+int	cache		# cache the input image pixels
+int	verify		# verify critical parameters
+int	update 		# update the critical parameter
+int	verbose		# verbose mode
+
+pointer	sp, outfname, ap, im, gd, id, cname, str
+int	cl, out, limlist, lclist, lolist, lid, sid, root, stat, memstat
+int	imlist, clist, olist, wcs, req_size, buf_size, old_size
+
+pointer	gopen(), immap()
+int	imtlen(), imtgetim(), clplen(), btoi(), clgfil(), fnldir()
+int	open(), strncmp(), strlen(), apfitpsf(), imtopenp(), clpopnu()
+int	clgwrd(), ap_memstat(), sizeof()
+bool	clgetb(), streq()
+errchk	gopen
+
+begin
+	# Allocate workin space.
+	call smark (sp)
+	call salloc (image, SZ_FNAME, TY_CHAR)
+	call salloc (output, SZ_FNAME, TY_CHAR)
+	call salloc (coords, SZ_FNAME, TY_CHAR)
+	call salloc (graphics, SZ_FNAME, TY_CHAR)
+	call salloc (display, SZ_FNAME, TY_CHAR)
+	call salloc (outfname, SZ_FNAME, TY_CHAR)
+	call salloc (cname, SZ_FNAME, TY_CHAR)
+	call salloc (str, SZ_LINE, TY_CHAR)
+
+	# Set standard output to flush on newline.
+	call fseti (STDOUT, F_FLUSHNL, YES)
+
+	# Get input image list.
+	imlist = imtopenp ("image")
+	limlist = imtlen (imlist)
+
+	# Get input coordinate lists.
+	clist = clpopnu ("coords")
+	lclist = clplen (clist)
+
+	# Get output file list and check for zero length list.
+	olist = clpopnu ("output")
+	lolist = clplen (olist)
+
+	# Check that image and coordinate list lengths match.
+	if (limlist < 1 || (lclist > 1 && lclist != limlist)) {
+	    call imtclose (imlist)
+	    call clpcls (clist)
+	    call clpcls (olist)
+	    call error (0, "Imcompatable image and coordinate list lengths")
+	}
+
+	# Check that image and output list lengths match.
+	if (lolist > 1 && lolist != limlist) {
+	    call imtclose (imlist)
+	    call clpcls (clist)
+	    call clpcls (olist)
+	    call error (0, "Imcompatable image and output list lengths")
+	}
+
+	call clgstr ("icommands.p_filename", Memc[cname], SZ_FNAME)
+	if (Memc[cname] != EOS)
+	    interactive = NO
+	#else if (lclist == 0)
+	    #interactive = YES
+	else
+	    interactive = btoi (clgetb ("interactive"))
+	cache = btoi (clgetb("cache"))
+	verify = btoi (clgetb ("verify"))
+	update = btoi (clgetb ("update"))
+	verbose = btoi (clgetb ("verbose"))
+
+	# Get the parameters.
+	call ap_gpfpars (ap)
+	if (verify == YES && interactive == NO) {
+	    call ap_pfconfirm (ap, NULL, 1)
+	    if (update == YES)
+		call ap_ppfpars (ap)
+	}
+
+        # Get the wcs information.
+        wcs = clgwrd ("wcsin", Memc[str], SZ_LINE, WCSINSTR)
+        if (wcs <= 0) {
+	    call eprintf (
+	        "Warning: Setting the input coordinate system to logical\n")
+            wcs = WCS_LOGICAL
+	}
+        call apseti (ap, WCSIN, wcs)
+        wcs = clgwrd ("wcsout", Memc[str], SZ_LINE, WCSOUTSTR)
+        if (wcs <= 0) {
+	    call eprintf (
+	        "Warning: Setting the output coordinate system to logical\n")
+            wcs = WCS_LOGICAL
+	}
+        call apseti (ap, WCSOUT, wcs)
+
+	# Get the graphics and display devices.
+	call clgstr ("graphics", Memc[graphics], SZ_FNAME)
+	call clgstr ("display", Memc[display], SZ_FNAME)
+
+	# Open the graphics and display devices.
+	if (interactive == YES) {
+	    if (Memc[graphics] == EOS)
+		gd = NULL
+	    else {
+		iferr {
+		    gd = gopen (Memc[graphics], APPEND+AW_DEFER, STDGRAPH)
+		} then {
+		    call eprintf (
+			"Warning: Error opening graphics device.\n")
+		    gd = NULL
+	  	}
+	    }
+	    if (Memc[display] == EOS)
+		id = NULL
+	    else if (streq (Memc[graphics], Memc[display]))
+		id = gd
+	    else {
+		iferr {
+		    id = gopen (Memc[display], APPEND, STDIMAGE)
+		} then {
+		    call eprintf (
+		"Warning: Graphics overlay not available for display device.\n")
+		    id = NULL
+		}
+	    }
+	} else {
+	    id = NULL
+	    gd = NULL
+	}
+
+	# Begin looping over the image list.
+	sid = 1
+	while (imtgetim (imlist, Memc[image], SZ_FNAME) != EOF) {
+
+	    # Open the image.
+	    im = immap (Memc[image], READ_ONLY, 0)
+	    call apimkeys (ap, im, Memc[image])
+
+	    # Set the image display viewport.
+	    if ((id != NULL) && (id != gd))
+		call ap_gswv (id, Memc[image], im, 4)
+
+	    # Cache the input image pixels.
+            req_size = MEMFUDGE * IM_LEN(im,1) * IM_LEN(im,2) *
+                sizeof (IM_PIXTYPE(im))
+            memstat = ap_memstat (cache, req_size, old_size)
+            if (memstat == YES)
+                call ap_pcache (im, INDEFI, buf_size)
+
+	    # Open coordinate file, where coords is assumed to be a simple text
+	    # file in which the x and y positions are in columns 1 and 2
+	    # respectively and all remaining fields are ignored.
+
+	    if (lclist <= 0) {
+		cl = NULL
+		call strcpy ("", Memc[outfname], SZ_FNAME)
+	    } else {
+		stat = clgfil (clist, Memc[coords], SZ_FNAME)
+		root = fnldir (Memc[coords], Memc[outfname], SZ_FNAME)
+		if (strncmp ("default", Memc[coords+root], 7) == 0 || root ==
+		    strlen (Memc[coords])) {
+		    call ap_inname (Memc[image], Memc[outfname], "coo",
+		        Memc[outfname], SZ_FNAME)
+		    lclist = limlist
+	            cl = open (Memc[outfname], READ_ONLY, TEXT_FILE)
+		} else if (stat != EOF) {
+		    call strcpy (Memc[coords], Memc[outfname], SZ_FNAME)
+	            cl = open (Memc[outfname], READ_ONLY, TEXT_FILE)
+		} else {
+		    call apstats (ap, CLNAME, Memc[outfname], SZ_FNAME)
+		    call seek (cl, BOF)
+		}
+	    }
+	    call apsets (ap, CLNAME, Memc[outfname])
+	    call apfroot (Memc[outfname], Memc[str], SZ_LINE)
+	    call apsets (ap, CLROOT, Memc[str])
+
+	    # Open output text file, if output is "default", dir$default or
+	    # a directory specification then the extension "psf" is added on
+	    # to the image name and a suitable version number is appended to
+	    # the output name. If the output string is null then no output
+	    # file is written.
+
+	    if (lolist == 0) {
+		out = NULL
+		call strcpy ("", Memc[outfname], SZ_FNAME)
+	    } else {
+	        stat = clgfil (olist, Memc[output], SZ_FNAME)
+		root = fnldir (Memc[output], Memc[outfname], SZ_FNAME)
+		if (strncmp ("default", Memc[output+root], 7) == 0 || root ==
+		    strlen (Memc[output])) {
+		    call apoutname (Memc[image], Memc[outfname], "psf",
+		        Memc[outfname], SZ_FNAME)
+		    out = open (Memc[outfname], NEW_FILE, TEXT_FILE)
+		    lolist = limlist
+		} else if (stat != EOF) {
+		    call strcpy (Memc[output], Memc[outfname], SZ_FNAME)
+		    out = open (Memc[outfname], NEW_FILE, TEXT_FILE)
+		} else
+		    call apstats (ap, OUTNAME, Memc[outfname], SZ_FNAME)
+	    }
+	    call apsets (ap, OUTNAME, Memc[outfname])
+
+	    # Fit the PSF.
+	    if (interactive == NO) {
+	        if (Memc[cname] != EOS)
+		    stat = apfitpsf (ap, im, cl, NULL, NULL, out, sid, NO,
+			cache)
+	        else if (cl != NULL) {
+		    lid = 1
+		    call apbfitpsf (ap, im, cl, out, id, sid, lid, verbose)
+		    stat = NO
+		} else
+		    stat = NO
+	    } else
+		stat = apfitpsf (ap, im, cl, gd, id, out, sid, YES, cache)
+
+	    # Cleanup.
+	    call imunmap (im)
+	    if (cl != NULL) {
+		if (lclist > 1)
+		    call close (cl)
+	    }
+	    if (out != NULL && lolist != 1) {
+		call close (out)
+		if (sid <= 1) {
+		    call apstats (ap, OUTNAME, Memc[outfname], SZ_FNAME)
+		    call delete (Memc[outfname])
+		}
+		sid = 1
+	    }
+
+	    # Uncache memory.
+	    call fixmem (old_size)
+
+	    if (stat == YES)
+		break
+	}
+
+	# Close the plot files.
+	if (id == gd && id != NULL)
+	    call gclose (id)
+	else {
+	    if (id != NULL)
+	        call gclose (id)
+	    if (gd != NULL)
+	        call gclose (gd)
+	}
+
+	# If only one coordinate file for a list of images close file.
+	if (cl != NULL && lclist == 1)
+	    call close (cl)
+
+	# If only one output file for a list of images close file.
+	if (out != NULL && lolist == 1) {
+	    call close (out)
+	    if (sid <= 1) {
+		call apstats (ap, OUTNAME, Memc[outfname], SZ_FNAME)
+	        call delete (Memc[outfname])
+	    }
+	}
+
+	# Close up the PSF fitting structure.
+	call apsffree (ap)
+
+	# Close up the lists.
+	call imtclose (imlist)
+	call clpcls (clist)
+	call clpcls (olist)
+
+	call sfree (sp)
+end
diff --git a/noao/digiphot/apphot/fitsky.par b/noao/digiphot/apphot/fitsky.par
new file mode 100644
index 00000000..3899b0e8
--- /dev/null
+++ b/noao/digiphot/apphot/fitsky.par
@@ -0,0 +1,21 @@
+# FITSKY
+
+image,f,a,,,,"The input image(s)"
+coords,f,h,"",,,"The input coordinate list(s) (default: image.coo.?)"
+output,f,h,"default",,,"The output sky file(s) (default: image.sky.?)"
+plotfile,f,h,"",,,"The output metacode plot file"
+datapars,pset,h,"",,,"Data dependent parameters"
+fitskypars,pset,h,"",,,"Sky fitting parameters"
+interactive,b,h,yes,,,"Interactive mode ?"
+radplots,b,h,no,,,"Plot radial profiles in interactive mode ?"
+icommands,*imcur,h,"",,,"Image cursor: [x y wcs] key [cmd]"
+gcommands,*gcur,h,"",,,"Graphics cursor: [x y wcs] key [cmd]"
+wcsin,s,h,)_.wcsin,,,"The input coordinate system (logical,tv,physical,world)"
+wcsout,s,h,)_.wcsout,,,"The output coordinate system (logical,tv,physical)"
+cache,b,h,)_.cache,,,"Cache the input image pixels in memory ?"
+verify,b,h,)_.verify,,,"Verify critical parameters in non-interactive mode ?"
+update,b,h,)_.update,,,"Update critical parameters in non-interactive mode ?"
+verbose,b,h,)_.verbose,,,"Print messages in non-interactive mode ?"
+graphics,s,h,)_.graphics,,,"Graphics device"
+display,s,h,)_.display,,,"Display device"
+mode,s,h,'ql'
diff --git a/noao/digiphot/apphot/fitsky/apavsky.x b/noao/digiphot/apphot/fitsky/apavsky.x
new file mode 100644
index 00000000..c7e38c0e
--- /dev/null
+++ b/noao/digiphot/apphot/fitsky/apavsky.x
@@ -0,0 +1,107 @@
+include "../lib/display.h"
+include "../lib/fitsky.h"
+
+# AP_AVSKY -- Compute an estimate of the sky value by averaging several
+# individual sky values measured in different parts of the frame.
+
+int procedure ap_avsky (ap, im, stid, sd, id, gd, interactive)
+
+pointer	ap			# the pointer to the main apphot data structure
+pointer	im			# the pointer to the input image
+int	stid			# the current sequence number
+int	sd			# the sky file descriptor
+pointer	id			# the display stream descriptor
+pointer	gd			# the graphics stream descriptor
+int	interactive		# interactive mode
+
+int	wcs, key, nmsky, nmsigma, nmskew, nsky, nrej, sier, ier
+pointer	sp, cmd
+real	wx, wy, msky, msigma, mskew
+int	clgcur(), apfitsky(), apstati()
+real	apstatr()
+
+begin
+	call smark (sp)
+	call salloc (cmd, SZ_LINE, TY_CHAR)
+
+	# Initialize the skyvalues.
+	msky = 0.0
+	nmsky = 0
+	msigma = 0.0
+	nmsigma = 0
+	mskew = 0.0
+	nmskew = 0
+	nsky = 0
+	nrej = 0
+	ier = AP_OK
+
+	call printf (
+	"\nMeasure sky around several cursor positions (t=measure, q=quit)\n")
+	while (clgcur ("icommands", wx, wy, wcs, key, Memc[cmd], SZ_LINE) !=
+	    EOF) {
+
+	    switch (key) {
+	    case 'q':
+		break
+
+	    case 't':
+		sier = apfitsky (ap, im, wx, wy, sd, gd)
+		if (sier != AP_OK)
+		    ier = sier
+
+		if (id != NULL) {
+		    call apmark (ap, id, NO, apstati (ap, MKSKY), NO)
+		    if (id == gd)
+			call gflush (id)
+		    else
+		        call gframe (id)
+		}
+		call ap_splot (ap, stid, gd, apstati (ap, RADPLOTS))
+		if (interactive == YES)
+		    call ap_qspsky (ap, sier)
+
+		if (! IS_INDEFR(apstatr (ap, SKY_MODE))) {
+		    msky = msky + apstatr (ap, SKY_MODE)
+		    nmsky = nmsky + 1
+		}
+		if (! IS_INDEFR(apstatr (ap, SKY_SIGMA))) {
+		    msigma = msigma + apstatr (ap, SKY_SIGMA)
+		    nmsigma = nmsigma + 1
+		}
+		if (! IS_INDEFR(apstatr (ap, SKY_SKEW))) {
+		    mskew = mskew + apstatr (ap, SKY_SKEW)
+		    nmskew = nmskew + 1
+		}
+		nsky = nsky + apstati (ap, NSKY)
+		nrej = nrej + apstati (ap, NSKY_REJECT)
+
+	    default:
+		;
+	    }
+	}
+
+	# Compute the average values.
+	if (nmsky > 0)
+	    msky = msky / nmsky
+	else
+	    msky = INDEFR
+	if (nmsigma > 0)
+	    msigma = msigma / nmsigma
+	else
+	    msigma = INDEFR
+	if (nmskew > 0)
+	    mskew = mskew / nmskew
+	else
+	    mskew = INDEFR
+
+	# Store the average values.
+	call apsetr (ap, SKY_MODE, msky)
+	call apsetr (ap, SKY_SIGMA, msigma)
+	call apsetr (ap, SKY_SKEW, mskew)
+	call apseti (ap, NSKY, nsky)
+	call apseti (ap, NSKY_REJECT, nrej)
+
+	call sfree (sp)
+
+	return (ier)
+end
diff --git a/noao/digiphot/apphot/fitsky/apbsky.x b/noao/digiphot/apphot/fitsky/apbsky.x
new file mode 100644
index 00000000..28e96288
--- /dev/null
+++ b/noao/digiphot/apphot/fitsky/apbsky.x
@@ -0,0 +1,98 @@
+include <fset.h>
+include "../lib/apphot.h"
+include "../lib/display.h"
+
+# APBSKY -- Procedure to determine the sky statistics for a list of objects
+# in batch mode using a simple coordinate list.
+
+procedure apbsky (ap, im, cl, sd, out, id, ld, gd, mgd, gid, interactive)
+
+pointer ap			# pointer to apphot structure
+pointer	im			# pointer to IRAF image
+int	cl			# starlist file descriptor
+int	sd			# sky file descriptor
+int	out			# output file descriptor
+int	id, ld			# sequence and list numbers
+int	gd			# pointer to stdgraph stream
+pointer	mgd			# pointer to graphics metacode file
+pointer	gid			# pointer to image display stream
+int	interactive		# interactive mode
+
+int	stdin, ier, ild
+pointer	sp, str
+real	wx, wy
+int	apfitsky(), fscan(), nscan(), strncmp(), apstati()
+
+begin
+	call smark (sp)
+	call salloc (str, SZ_FNAME, TY_CHAR)
+	call fstats (cl, F_FILENAME, Memc[str], SZ_FNAME)
+
+	# Initialize.
+	ild = ld
+
+	# Print the query.
+	if (strncmp ("STDIN", Memc[str], 5) == 0) {
+	    stdin = YES
+	    call printf ("Type object x and y coordinates (^D or ^Z to end): ")
+	    call flush (STDOUT)
+	} else
+	    stdin = NO
+
+	# Loop over the coordinate file.
+	while (fscan (cl) != EOF) {
+
+	    # Fetch and store the coordinates.
+	    call gargr (wx)
+	    call gargr (wy)
+	    if (nscan () != 2) {
+		if (stdin == YES) {
+	    	    call printf (
+		        "Type object x and y coordinates (^D or ^Z to end): ")
+	    	    call flush (STDOUT)
+		} 
+		next
+	    }
+
+            # Transform the input coordinates.
+            switch (apstati(ap,WCSIN)) {
+            case WCS_WORLD, WCS_PHYSICAL:
+                call ap_itol (ap, wx, wy, wx, wy, 1)
+            case WCS_TV:
+                call ap_vtol (im, wx, wy, wx, wy, 1)
+            default:
+                ;
+            }
+	    call apsetr (ap, CWX, wx)
+	    call apsetr (ap, CWY, wy)
+
+	    # Fit the sky value.
+	    ier = apfitsky (ap, im, wx, wy, sd, gd)
+
+	    # Print the sky values.
+	    if (interactive == YES) {
+		call ap_qspsky (ap, ier)
+		if (gid != NULL)
+		    call apmark (ap, gid, NO, apstati (ap, MKSKY), NO)
+	    }
+	    call ap_splot(ap, id, mgd, YES)
+	    if (id == 1)
+	        call ap_param (ap, out, "fitsky")
+	    call ap_pssky (ap, out, id, ild, ier)
+
+	    # Set up for the next object.
+	    id = id + 1
+	    ild = ild + 1
+	    call apsetr (ap, WX, wx)
+	    call apsetr (ap, WY, wy)
+
+	    # print query
+	    if (stdin == YES) {
+		call printf (
+		    "Type object x and y coordinates (^D or ^Z to end): ")
+		call flush (STDOUT)
+	    } 
+	}
+
+	call sfree (sp)
+end
diff --git a/noao/digiphot/apphot/fitsky/apcentroid.x b/noao/digiphot/apphot/fitsky/apcentroid.x
new file mode 100644
index 00000000..310db85d
--- /dev/null
+++ b/noao/digiphot/apphot/fitsky/apcentroid.x
@@ -0,0 +1,244 @@
+include <mach.h>
+include "../lib/fitsky.h"
+
+# AP_CENTROID -- Procedure to find the mode, width and skew of the sky
+# distribution by computing the moments of the histogram. 
+
+int procedure ap_centroid (skypix, coords, wgt, index, nskypix, snx, sny, k1,
+	hwidth, binsize, smooth, losigma, hisigma, rgrow, maxiter, sky_mode,
+	sky_sigma, sky_skew, nsky, nsky_reject)
+
+real	skypix[ARB]		# array of sky pixels
+int	coords[ARB]		# array of coordinates for regions growing
+real	wgt[ARB]		# array of weights for rejection
+int	index[ARB]		# array of sorted indices
+int	nskypix			# the number of sky pixels
+int	snx, sny		# the maximum dimensions of sky raster
+real	k1			# extent of the histogram in skysigma
+real	hwidth			# width of the histogram
+real	binsize			# the size of the histogram in sky sigma
+int	smooth			# smooth the histogram before fitting
+real	losigma, hisigma	# upper and lower k-sigma rejection limits
+real	rgrow			# region growing radius in pixels
+int	maxiter			# maximum number of rejection cycles
+real	sky_mode		# computed sky value
+real	sky_sigma		# computed sigma of the sky pixels
+real	sky_skew		# skew of sky pixels
+int	nsky			# number of sky pixels used in fit
+int	nsky_reject		# number of sky pixels rejected
+
+double	dsky, sumpx, sumsqpx, sumcbpx
+int	nreject, nbins, nker, ier, i, j
+pointer	sp, hgm, shgm
+real	dmin, dmax, sky_mean, hmin, hmax, dh, locut, hicut, cut
+real	sky_zero
+int	ap_grow_hist2(), aphigmr()
+real	ap_asumr(), apmedr()
+
+begin
+	# Intialize.
+	nsky = nskypix
+	nsky_reject = 0
+	sky_mode = INDEFR
+	sky_sigma = INDEFR
+	sky_skew = INDEFR
+	if (nskypix <= 0)
+	    return (AP_NOSKYAREA)
+
+	# Compute the histogram width and binsize.
+	sky_zero = ap_asumr (skypix, index, nskypix) / nskypix
+	call ap_ialimr (skypix, index, nskypix, dmin, dmax)
+	call apfimoments (skypix, index, nskypix, sky_zero, sumpx, sumsqpx,
+	    sumcbpx, sky_mean, sky_sigma, sky_skew)
+	sky_mean = apmedr (skypix, index, nskypix)
+	sky_mean = max (dmin, min (sky_mean, dmax))
+	if (! IS_INDEFR(hwidth) && hwidth > 0.0) {
+	    hmin = sky_mean - k1 * hwidth
+	    hmax = sky_mean + k1 * hwidth
+	    dh = binsize * hwidth
+	} else {
+	    cut = min (sky_mean - dmin, dmax - sky_mean, k1 * sky_sigma)
+	    hmin = sky_mean - cut
+	    hmax = sky_mean + cut
+	    dh = binsize * cut / k1
+	}
+
+	# Compute the number of histogram bins and the histogram resolution.
+	if (dh <= 0.0) {
+	    nbins = 1
+	    dh = 0.0
+	} else {
+	    nbins = 2 * nint ((hmax - sky_mean) / dh) + 1
+	    dh = (hmax - hmin) / (nbins - 1)
+	}
+
+	# Check for a valid histogram.
+	if (nbins < 2 || k1 <= 0.0 || sky_sigma < dh || dh <= 0.0 ||
+	    sky_sigma <= 0.0) {
+	    sky_mode = sky_mean
+	    sky_sigma = 0.0
+	    sky_skew = 0.0
+	    return (AP_NOHISTOGRAM)
+	}
+
+	# Allocate temporary space.
+	call smark (sp)
+	call salloc (hgm, nbins, TY_REAL)
+	call salloc (shgm, nbins, TY_REAL)
+
+	# Accumulate the histogram.
+	call aclrr (Memr[hgm], nbins)
+	nsky_reject = nsky_reject + aphigmr (skypix, wgt, index, nskypix,
+	    Memr[hgm], nbins, hmin, hmax)
+	nsky = nskypix - nsky_reject
+
+	# Do the initial rejection.
+	if (nsky_reject > 0) {
+	    do i = 1, nskypix {
+		if (wgt[index[i]] <= 0.0) {
+		    dsky = skypix[index[i]] - sky_zero
+		    sumpx = sumpx - dsky
+		    sumsqpx = sumsqpx - dsky ** 2
+		    sumcbpx = sumcbpx - dsky ** 3
+		}
+	    }
+	    call apmoments (sumpx, sumsqpx, sumcbpx, nsky, sky_zero, sky_mean,
+	        sky_sigma, sky_skew)
+	}
+
+	# Fit the mode, sigma an skew of the histogram.
+	if (smooth == YES) {
+	    nker = max (1, nint (sky_sigma / dh))
+	    #call ap_lucy_smooth (Memr[hgm], Memr[shgm], nbins, nker, 2)
+	    call ap_bsmooth (Memr[hgm], Memr[shgm], nbins, nker, 2)
+	    call ap_imode (Memr[shgm], nbins, hmin, hmax, YES, sky_mode, ier)
+	} else
+	    call ap_imode (Memr[hgm], nbins, hmin, hmax, NO, sky_mode, ier)
+	sky_mode = max (dmin, min (sky_mode, dmax))
+	if ((IS_INDEFR(losigma) && IS_INDEFR(hisigma)) || (sky_sigma < dh) ||
+	    maxiter < 1) {
+	    call sfree (sp)
+	    return (AP_OK)
+	}
+
+	# Fit histogram with pixel rejection and optional region growing.
+	do i = 1, maxiter {
+
+	    # Compute new histogram limits.
+	    if (IS_INDEFR(losigma))
+		locut = -MAX_REAL
+	    else
+	        locut = sky_mode - losigma * sky_sigma
+	    if (IS_INDEFR(hisigma))
+		hicut = MAX_REAL
+	    else
+	        hicut = sky_mode + hisigma * sky_sigma
+
+	    # Reject pixels.
+	    nreject = 0
+	    do j = 1, nskypix {
+		if (skypix[index[j]] >= locut && skypix[index[j]] <= hicut)
+		    next
+		if (rgrow > 0.0)
+		    nreject = nreject + ap_grow_hist2 (skypix, coords,
+			wgt, nskypix, sky_zero, index[j], snx, sny, Memr[hgm],
+			nbins, hmin, hmax, rgrow, sumpx, sumsqpx, sumcbpx)
+		else if (wgt[index[j]] > 0.0) {
+		    call ap_hgmsub2 (Memr[hgm], nbins, hmin, hmax,
+		        skypix[index[j]], sky_zero, sumpx, sumsqpx, sumcbpx)
+		    wgt[index[j]] = 0.0
+		    nreject = nreject + 1
+		}
+	    }
+	    if (nreject == 0)
+		break
+	    nsky_reject = nsky_reject + nreject
+	    nsky = nskypix - nsky_reject 
+	    if (nsky <= 0)
+		break
+
+	    # Recompute the moments.
+	    call apmoments (sumpx, sumsqpx, sumcbpx, nsky, sky_zero, sky_mean,
+	        sky_sigma, sky_skew)
+
+	    # Recompute the histogram peak.
+	    if (smooth == YES) {
+		nker = max (1, nint (sky_sigma / dh))
+	        #call ap_lucy_smooth (Memr[hgm], Memr[shgm], nbins, nker, 2)
+	        call ap_bsmooth (Memr[hgm], Memr[shgm], nbins, nker, 2)
+	        call ap_imode (Memr[shgm], nbins, hmin, hmax, YES, sky_mode,
+		    ier)
+	    } else
+	        call ap_imode (Memr[hgm], nbins, hmin, hmax, NO, sky_mode, ier)
+	    sky_mode = max (dmin, min (sky_mode, dmax))
+	    if (sky_sigma <= dh || ier != AP_OK)
+		break
+	}
+
+	# Return the error codes.
+	call sfree (sp)
+	if (nsky == 0 || nsky_reject == nskypix || ier == AP_NOHISTOGRAM) {
+	    nsky = 0
+	    nsky_reject = nskypix
+	    sky_mode = INDEFR
+	    sky_sigma = INDEFR
+	    sky_skew = INDEFR
+	    return (AP_NSKY_TOO_SMALL)
+	} else
+	    return (AP_OK)
+end
+
+
+# AP_IMODE -- Procedure to compute the 1st, 2nd and third moments of the
+# histogram of sky pixels.
+
+procedure ap_imode (hgm, nbins, z1, z2, smooth, sky_mode, ier)
+
+real	hgm[ARB]		# histogram
+int	nbins			# number of bins
+real	z1, z2			# min and max of the histogram
+int	smooth			# is the histogram smoothed
+real	sky_mode		# mode of histogram
+int	ier			# error code
+
+int	i, noccup
+double	sumi, sumix, x, dh
+real	hmean, dz
+real	asumr()
+
+begin
+	# Initialize the sums.
+	sumi = 0.0
+	sumix = 0.0
+
+	# Compute a continuum level.
+	if (smooth == NO) 
+	    hmean = asumr (hgm, nbins) / nbins
+	else {
+	    call alimr (hgm, nbins, dz, hmean)
+	    hmean = 2.0 * hmean / 3.0
+	}
+
+	# Accumulate the sums.
+	noccup = 1
+	dz = (z2 - z1) / (nbins - 1)
+	x = z1 + 0.5 * dz
+	do i = 1, nbins {
+	    dh = hgm[i] - hmean
+	    if (dh > 0.0d0) {
+	        sumi = sumi + dh
+	        sumix = sumix + dh * x
+	        noccup = noccup + 1
+	    }
+	    x = x + dz
+	}
+
+	# Compute the sky mode, sigma and skew.
+	if (sumi > 0.0) {
+	    sky_mode = sumix / sumi
+	    ier = AP_OK
+	} else {
+	    sky_mode = INDEFR
+	    ier = AP_NOHISTOGRAM
+	}
+end
diff --git a/noao/digiphot/apphot/fitsky/apcrosscor.x b/noao/digiphot/apphot/fitsky/apcrosscor.x
new file mode 100644
index 00000000..757addcc
--- /dev/null
+++ b/noao/digiphot/apphot/fitsky/apcrosscor.x
@@ -0,0 +1,288 @@
+include <mach.h>
+include "../lib/fitsky.h"
+
+# AP_CROSSCOR -- Procedure to compute the sky value by calculating the
+# cross-correlation function of the histogram of the sky pixels and
+# a Gaussian function with the same sigma as the sky distribution.
+# The peak of the cross-correlation function is found by parabolic
+# interpolation.
+
+int procedure ap_crosscor (skypix, coords, wgt, index, nskypix, snx, sny, k1,
+	hwidth, binsize, smooth, losigma, hisigma, rgrow, maxiter, sky_mode,
+	sky_sigma, sky_skew, nsky, nsky_reject)
+
+real	skypix[ARB]		# array of sky pixels
+int	coords[ARB]		# array of sky coordinates for region growing
+real	wgt[ARB]		# array of weights for rejection
+int	index[ARB]		# array of sort indices
+int	nskypix			# the number of sky pixels
+int	snx, sny		# the maximum dimensions of sky raster
+real	k1			# half-width of the histogram in sky sigma
+real	hwidth			# the input sky sigma
+real	binsize			# the size of the histogram in sky sigma
+int	smooth			# smooth the histogram before fitting (not used)
+real	losigma, hisigma	# upper and lower rejection limits
+real	rgrow			# region growing radius in pixels
+int	maxiter			# maximum number of rejection cycles
+real	sky_mode		# computed sky value
+real	sky_sigma		# computed standard deviation of the sky pixels
+real	sky_skew		# computed skew of sky pixels
+int	nsky			# number of sky pixels used in fit
+int	nsky_reject		# number of sky pixels rejected
+
+double 	dsky, sumpx, sumsqpx, sumcbpx
+int	nreject, nbins, nker, nsmooth, ier, i, j
+pointer	sp, x, hgm, shgm, kernel
+real	dmin, dmax, hmin, hmax, dh, kmin, kmax, locut, hicut, sky_mean, cut
+real	sky_zero
+int	ap_grow_hist2(), aphigmr()
+real	ap_asumr(), apmedr()
+
+begin
+	# Initialize.
+	nsky = nskypix
+	nsky_reject = 0
+	sky_mode = INDEFR
+	sky_sigma = INDEFR
+	sky_skew = INDEFR
+	if (nskypix <= 0)
+	    return (AP_NOSKYAREA)
+
+	# Set up initial guess at sky mean, sigma and skew.
+	sky_zero = ap_asumr (skypix, index, nskypix) / nskypix
+	call ap_ialimr (skypix, index, nskypix, dmin, dmax)
+	call apfimoments (skypix, index, nskypix, sky_zero,
+	    sumpx, sumsqpx, sumcbpx, sky_mean, sky_sigma, sky_skew)
+	sky_mean = apmedr (skypix, index, nskypix)
+	sky_mean = max (dmin, min (sky_mean, dmax))
+
+	# Compute the width and bin size of the histogram.
+	if (! IS_INDEFR(hwidth) && hwidth > 0.0) {
+	    hmin = sky_mean - k1 * hwidth
+	    hmax = sky_mean + k1 * hwidth
+	    dh = binsize * hwidth
+	} else {
+	    cut = min (sky_mean - dmin, dmax - sky_mean, k1 * sky_sigma)
+	    hmin = sky_mean - cut
+	    hmax = sky_mean + cut
+	    dh = binsize * cut / k1
+	} 
+
+	# Compute the number of bins in and the width of the kernel.
+	if (dh <= 0.0) {
+	    nbins = 1
+	    nker = 1
+	    nsmooth = 1
+	    dh = 0.0
+	} else {
+    	    nbins = 2 * nint ((hmax - sky_mean) / dh) + 1
+	    nker = 2 * nint (2.0 * (hmax - sky_mean) / (dh * 3.0)) + 1
+	    nsmooth = nbins - nker + 1
+	    dh = (hmax - hmin) / (nbins - 1)
+	}
+	kmin = - dh * (nker / 2 + 0.5)
+	kmax = dh * (nker / 2 + 0.5)
+
+	# Test for a valid histogram.
+	if (nbins < 2 || k1 <= 0.0 || sky_sigma <= 0.0 || dh <= 0.0 ||
+	    sky_sigma <= dh) {
+	    sky_mode = sky_mean
+	    sky_sigma = 0.0
+	    sky_skew = 0.0
+	    return (AP_NOHISTOGRAM)
+	}
+
+	# Allocate space for the histogram and kernel.
+	call smark (sp)
+	call salloc (x, nbins, TY_REAL)
+	call salloc (hgm, nbins, TY_REAL)
+	call salloc (shgm, nbins, TY_REAL)
+	call salloc (kernel, nker, TY_REAL)
+
+	# Set up x array.
+	do i = 1, nbins
+	    Memr[x+i-1] = i
+	call amapr (Memr[x], Memr[x], nbins, 1.0, real (nbins),
+	    hmin + 0.5 * dh, hmax + 0.5 * dh)
+
+	# Accumulate the histogram.
+	call aclrr (Memr[hgm], nbins)
+	call aclrr (Memr[shgm], nbins)
+	nsky_reject = nsky_reject + aphigmr (skypix, wgt, index, nskypix,
+	    Memr[hgm], nbins, hmin, hmax)
+	nsky = nskypix - nsky_reject
+
+	# Perform the initial rejection cycle.
+	if (nsky_reject > 0.0) {
+	    do i = 1, nskypix {
+	        if (wgt[index[i]] <= 0.0) {
+		    dsky = skypix[index[i]] - sky_zero
+		    sumpx = sumpx - dsky
+		    sumsqpx = sumsqpx - dsky ** 2
+		    sumcbpx = sumcbpx - dsky ** 3
+		}
+	    }
+	    call apmoments (sumpx, sumsqpx, sumcbpx, nsky, sky_zero, sky_mean,
+	        sky_sigma, sky_skew)
+	}
+
+	# Construct kernel and convolve with histogram.
+	if (sky_sigma > 0.0) {
+	    call ap_gauss_kernel (Memr[kernel], nker, kmin, kmax, sky_sigma)
+	    call acnvr (Memr[hgm], Memr[shgm+nker/2], nsmooth, Memr[kernel],
+	        nker)
+	} else
+	    call amovr (Memr[hgm], Memr[shgm], nbins)
+	call ap_corfit (Memr[x], Memr[shgm], nbins, sky_mode, ier)
+	sky_mode = max (dmin, min (sky_mode, dmax))
+	if (ier != OK) {
+	    call sfree (sp)
+	    return (ier)
+	}
+	if ((IS_INDEFR(losigma) && IS_INDEFR(hisigma)) || (sky_sigma <= dh) ||
+	    maxiter < 1) {
+	    call sfree (sp)
+	    return (AP_OK)
+	}
+
+	# Fit histogram with pixel rejection and optional region growing.
+	do i = 1, maxiter {
+
+	    # Compute new histogram limits.
+	    if (IS_INDEFR(losigma))
+		locut = -MAX_REAL
+	    else
+	        locut = sky_mode - losigma * sky_sigma
+	    if (IS_INDEFR(hisigma))
+		hicut = MAX_REAL
+	    else
+	        hicut = sky_mode + hisigma * sky_sigma
+
+	    # Detect rejected pixels.
+	    nreject = 0
+	    do j = 1, nskypix {
+		if (skypix[index[j]] >= locut && skypix[index[j]] <= hicut)
+		    next
+		if (rgrow > 0.0)
+		    nreject = nreject + ap_grow_hist2 (skypix, coords,
+			wgt, nskypix, sky_zero, index[j], snx, sny,
+			Memr[hgm], nbins, hmin, hmax, rgrow, sumpx, sumsqpx,
+			sumcbpx)
+		else if (wgt[index[j]] > 0.0) {
+		    call ap_hgmsub2 (Memr[hgm], nbins, hmin, hmax,
+			skypix[index[j]], sky_zero, sumpx, sumsqpx, sumcbpx)
+		    wgt[index[j]] = 0.0
+		    nreject = nreject + 1
+		}
+	    }
+	    if (nreject == 0)
+		break
+
+	    # Update the sky parameters.
+	    nsky_reject = nsky_reject + nreject
+	    nsky = nskypix - nsky_reject 
+	    if (nsky <= 0)
+		break
+	    call apmoments (sumpx, sumsqpx, sumcbpx, nsky, sky_zero, sky_mean,
+	        sky_sigma, sky_skew)
+	    if (sky_sigma <= dh)
+		break
+
+	    # Recompute the peak of the histogram.
+	    call ap_gauss_kernel (Memr[kernel], nker, kmin, kmax, sky_sigma)
+	    call aclrr (Memr[shgm], nbins)
+	    call acnvr (Memr[hgm], Memr[shgm+nker/2], nsmooth, Memr[kernel],
+	        nker)
+	    call ap_corfit (Memr[x], Memr[shgm], nbins, sky_mode, ier)
+	    sky_mode = max (dmin, min (sky_mode, dmax))
+	    if (ier != AP_OK)
+		 break
+	}
+
+	# Return the appropriate error code.
+	call sfree (sp)
+	if (nsky == 0 || nsky_reject == nskypix) {
+	    nsky = 0
+	    nsky_reject = nskypix
+	    sky_mode = INDEFR
+	    sky_sigma = INDEFR
+	    sky_skew = INDEFR
+	    return (AP_NSKY_TOO_SMALL)
+	} else if (ier != AP_OK) {
+	    sky_mode = sky_mean
+	    sky_sigma = 0.0
+	    sky_skew = 0.0 
+	    return (ier)
+	} else
+	    return (AP_OK)
+end
+
+
+# AP_GAUSS_KERNEL -- Procedure to compute a Gaussian kernel of given length
+# and sigma.
+
+procedure ap_gauss_kernel (kernel, nker, kmin, kmax, sky_sigma)
+
+real	kernel[ARB]		# kernel 
+int	nker			# length of kernel
+real	kmin, kmax		# limits of the kernel
+real	sky_sigma		# sigma of the sky
+
+int	i
+real	dk, x, sumx
+
+begin
+	# Return 1 if unit sized kernel.
+	if (nker == 1) {
+	    kernel[1] = 1.0
+	    return
+	}
+
+	# Intialize.
+	sumx = 0.0
+	x = kmin
+	dk = (kmax - kmin ) / (nker - 1)
+
+ 	# Compute and normalize the kernel.
+	do i = 1, nker {
+	    kernel[i] = exp (- (x ** 2) / (2. * sky_sigma ** 2))
+	    sumx = sumx + kernel[i]
+	    x = x + dk
+	}
+        do i = 1, nker
+            kernel[i] = kernel[i] / sumx
+end
+
+
+# AP_CORFIT -- Procedure to compute the peak of the cross-correlation
+# function using parabolic interpolation.
+
+procedure ap_corfit (x, shgm, nbins, sky_mode, ier)
+
+real	x[ARB]				# x coordinates of histogram
+real	shgm[ARB]			# convolved histogram
+int	nbins				# number of histogram bins
+real	sky_mode			# computed sky_mode
+int	ier				# error code
+
+int	bin
+real	max, xo, dh1, dh2
+
+begin
+	call ap_amaxel (shgm, nbins, max, bin)
+	if (max <= 0) {
+	    ier = AP_FLAT_HIST
+	} else if (bin == 1) {
+	    sky_mode = x[1]
+	    ier = AP_OK
+	} else if (bin == nbins) {
+	    sky_mode = x[nbins]
+	    ier = AP_OK
+	} else {
+	    xo = 0.5 * (x[bin] + x[bin-1])
+	    dh1 = shgm[bin] - shgm[bin-1] 
+	    dh2 = shgm[bin] - shgm[bin+1]
+	    sky_mode = xo + (x[bin] - x[bin-1]) * (dh1 / (dh1 + dh2))
+	    ier = AP_OK
+	}
+end
diff --git a/noao/digiphot/apphot/fitsky/apfitsky.x b/noao/digiphot/apphot/fitsky/apfitsky.x
new file mode 100644
index 00000000..1c105b79
--- /dev/null
+++ b/noao/digiphot/apphot/fitsky/apfitsky.x
@@ -0,0 +1,452 @@
+include "../lib/apphotdef.h"
+include "../lib/apphot.h"
+include "../lib/noisedef.h"
+include "../lib/fitskydef.h"
+include "../lib/fitsky.h"
+
+# APFITSKY -- Procedure to the compute the sky value in an annular region
+# around a given position in the IRAF image.
+
+int procedure apfitsky (ap, im, wx, wy, sd, gd)
+
+pointer	ap		# pointer to the apphot structure
+pointer	im		# pointer to the IRAF image
+real	wx		# object x coordinate
+real	wy		# object y coordinate
+int	sd		# pointer to input text file containing sky values
+pointer	gd		# pointer to graphics stream
+
+int	ier, nclip, nsky, ilo, ihi
+pointer	sky, nse, gt
+real	x, y
+int	apskybuf(), ap_mode(), ap_centroid(), ap_histplot(), ap_readsky()
+int	ap_median(), ap_radplot(), ap_gauss(), ap_lgsky(), ap_crosscor()
+int	ap_mean(), ap_clip()
+pointer	ap_gtinit()
+
+begin
+	# Initialize.
+	sky = AP_PSKY(ap)
+	nse = AP_NOISE(ap)
+	AP_SXCUR(sky) = wx
+	AP_SYCUR(sky) = wy
+        if (IS_INDEFR(wx) || IS_INDEFR(wy)) {
+            AP_OSXCUR(sky) = INDEFR
+            AP_OSYCUR(sky) = INDEFR
+        } else {
+            switch (AP_WCSOUT(ap)) {
+            case WCS_WORLD, WCS_PHYSICAL:
+                call ap_ltoo (ap, wx, wy, AP_OSXCUR(sky), AP_OSYCUR(sky), 1)
+            case WCS_TV:
+                call ap_ltov (im, wx, wy, AP_OSXCUR(sky), AP_OSYCUR(sky), 1)
+            default:
+                AP_OSXCUR(sky) = wx
+                AP_OSYCUR(sky) = wy
+            }
+        }
+
+	AP_SKY_MODE(sky) = INDEFR
+	AP_SKY_SIG(sky) = INDEFR
+	AP_SKY_SKEW(sky) = INDEFR
+	AP_NSKY(sky) = 0
+	AP_NSKY_REJECT(sky) = 0
+	if (IS_INDEFR(wx) || IS_INDEFR(wy))
+	    return (AP_NOSKYAREA)
+
+	switch (AP_SKYFUNCTION(sky)) {
+
+	case AP_MEAN:
+
+	    # Fetch  the sky pixels.
+	    ier = apskybuf (ap, im, wx, wy)
+	    if (ier != AP_OK)
+		return (ier)
+
+	    # Initialze the weights.
+	    call amovkr (1.0, Memr[AP_SWGT(sky)], AP_NSKYPIX(sky))
+
+	    # Clip the data.
+	    if (AP_SLOCLIP(sky) > 0.0 || AP_SHICLIP(sky) > 0.0) {
+		nclip = ap_clip (Memr[AP_SKYPIX(sky)], Memi[AP_INDEX(sky)],
+		    AP_NSKYPIX(sky), AP_SLOCLIP(sky), AP_SHICLIP(sky), ilo,
+		    ihi)
+		if (nclip >= AP_NSKYPIX(sky))
+		    return (AP_NSKY_TOO_SMALL)
+		nsky = AP_NSKYPIX(sky) - nclip
+	    } else {
+		nclip = 0
+		call ap_index (Memi[AP_INDEX(sky)], AP_NSKYPIX(sky))
+		ilo = 1
+		nsky = AP_NSKYPIX(sky) 
+	    }
+
+	    # Compute the mean of the sky pixel distribution with pixel
+	    # rejection and region growing.
+	    ier = ap_mean (Memr[AP_SKYPIX(sky)], Memi[AP_COORDS(sky)],
+	        Memr[AP_SWGT(sky)], Memi[AP_INDEX(sky)+ilo-1],
+		nsky, AP_SNX(sky), AP_SNY(sky), AP_SLOREJECT(sky),
+		AP_SHIREJECT(sky), AP_RGROW(sky) * AP_SCALE(ap),
+		AP_SNREJECT(sky), AP_SKY_MODE(sky), AP_SKY_SIG(sky),
+		AP_SKY_SKEW(sky), AP_NSKY(sky), AP_NSKY_REJECT(sky))
+		AP_NSKY_REJECT(sky) = AP_NBADSKYPIX(sky) + nclip +
+		    AP_NSKY_REJECT(sky)
+
+	    return (ier)
+
+	case AP_MEDIAN:
+
+	    # Fetch  the sky pixels.
+	    ier = apskybuf (ap, im, wx, wy)
+	    if (ier != AP_OK)
+		return (ier)
+
+	    # Initialze the weights.
+	    call amovkr (1.0, Memr[AP_SWGT(sky)], AP_NSKYPIX(sky))
+
+	    # Clip the data.
+	    if (AP_SLOCLIP(sky) > 0.0 || AP_SHICLIP(sky) > 0.0) {
+		nclip = ap_clip (Memr[AP_SKYPIX(sky)], Memi[AP_INDEX(sky)],
+		    AP_NSKYPIX(sky), AP_SLOCLIP(sky), AP_SHICLIP(sky), ilo,
+		    ihi)
+		if (nclip >= AP_NSKYPIX(sky))
+		    return (AP_NSKY_TOO_SMALL)
+		nsky = AP_NSKYPIX(sky) - nclip
+	    } else {
+		nclip = 0
+		call apqsort (Memr[AP_SKYPIX(sky)], Memi[AP_INDEX(sky)],
+		    Memi[AP_INDEX(sky)], AP_NSKYPIX(sky))
+		ilo = 1
+		nsky = AP_NSKYPIX(sky) 
+	    }
+
+	    # Compute the median of the sky pixel distribution with pixel
+	    # rejection and region growing.
+	    ier = ap_median (Memr[AP_SKYPIX(sky)], Memi[AP_COORDS(sky)],
+	        Memr[AP_SWGT(sky)], Memi[AP_INDEX(sky)+ilo-1], nsky,
+		AP_SNX(sky), AP_SNY(sky), AP_SLOREJECT(sky),
+		AP_SHIREJECT(sky), AP_RGROW(sky) * AP_SCALE(ap),
+		AP_SNREJECT(sky), AP_SKY_MODE(sky), AP_SKY_SIG(sky),
+		AP_SKY_SKEW(sky), AP_NSKY(sky), AP_NSKY_REJECT(sky))
+	    AP_NSKY_REJECT(sky) = AP_NBADSKYPIX(sky) + nclip +
+	        AP_NSKY_REJECT(sky)
+
+	    return (ier)
+
+	case AP_MODE:
+
+	    # Fetch the sky pixels.
+	    ier = apskybuf (ap, im, wx, wy)
+	    if (ier != AP_OK)
+		return (ier)
+
+	    # Initialze the weights.
+	    call amovkr (1.0, Memr[AP_SWGT(sky)], AP_NSKYPIX(sky))
+
+	    # Clip the data.
+	    if (AP_SLOCLIP(sky) > 0.0 || AP_SHICLIP(sky) > 0.0) {
+		nclip = ap_clip (Memr[AP_SKYPIX(sky)], Memi[AP_INDEX(sky)],
+		    AP_NSKYPIX(sky), AP_SLOCLIP(sky), AP_SHICLIP(sky), ilo,
+		    ihi)
+		if (nclip >= AP_NSKYPIX(sky))
+		    return (AP_NSKY_TOO_SMALL)
+		nsky = AP_NSKYPIX(sky) - nclip
+	    } else {
+		nclip = 0
+		call apqsort (Memr[AP_SKYPIX(sky)], Memi[AP_INDEX(sky)],
+		    Memi[AP_INDEX(sky)], AP_NSKYPIX(sky))
+		ilo = 1
+		nsky = AP_NSKYPIX(sky) 
+	    }
+
+	    # Compute the median of the sky pixel distribution with pixel
+	    # rejection and region growing.
+	    ier = ap_mode (Memr[AP_SKYPIX(sky)], Memi[AP_COORDS(sky)],
+	        Memr[AP_SWGT(sky)], Memi[AP_INDEX(sky)+ilo-1], nsky,
+		AP_SNX(sky), AP_SNY(sky), AP_SLOREJECT(sky),
+		AP_SHIREJECT(sky), AP_RGROW(sky) * AP_SCALE(ap),
+		AP_SNREJECT(sky), AP_SKY_MODE(sky), AP_SKY_SIG(sky),
+		AP_SKY_SKEW(sky), AP_NSKY(sky), AP_NSKY_REJECT(sky))
+	    AP_NSKY_REJECT(sky) = AP_NBADSKYPIX(sky) + nclip +
+	        AP_NSKY_REJECT(sky)
+
+	    return (ier)
+
+	case AP_CENTROID:
+
+	    # Fetch the sky pixels.
+	    ier = apskybuf (ap, im, wx, wy)
+	    if (ier != AP_OK)
+		return (ier)
+
+	    # Initialze the weights.
+	    call amovkr (1.0, Memr[AP_SWGT(sky)], AP_NSKYPIX(sky))
+
+	    # Clip the data.
+	    if (AP_SLOCLIP(sky) > 0.0 || AP_SHICLIP(sky) > 0.0) {
+		nclip = ap_clip (Memr[AP_SKYPIX(sky)], Memi[AP_INDEX(sky)],
+		    AP_NSKYPIX(sky), AP_SLOCLIP(sky), AP_SHICLIP(sky), ilo,
+		    ihi)
+		if (nclip >= AP_NSKYPIX(sky))
+		    return (AP_NSKY_TOO_SMALL)
+		nsky = AP_NSKYPIX(sky) - nclip
+	    } else {
+		nclip = 0
+		call ap_index (Memi[AP_INDEX(sky)], AP_NSKYPIX(sky))
+		ilo = 1
+		nsky = AP_NSKYPIX(sky) 
+	    }
+
+	    # Compute the sky value by performing a moment analysis of the
+	    # sky pixel histogram.
+	    ier = ap_centroid (Memr[AP_SKYPIX(sky)], Memi[AP_COORDS(sky)],
+	        Memr[AP_SWGT(sky)], Memi[AP_INDEX(sky)+ilo-1], nsky,
+		AP_SNX(sky), AP_SNY(sky), AP_K1(sky), INDEFR,
+		AP_BINSIZE(sky), AP_SMOOTH(sky), AP_SLOREJECT(sky),
+		AP_SHIREJECT(sky), AP_RGROW(sky) * AP_SCALE(ap),
+		AP_SMAXITER(sky), AP_SKY_MODE(sky), AP_SKY_SIG(sky),
+		AP_SKY_SKEW(sky), AP_NSKY(sky), AP_NSKY_REJECT(sky))
+	    AP_NSKY_REJECT(sky) = AP_NBADSKYPIX(sky) + nclip +
+	        AP_NSKY_REJECT(sky)
+
+	    return (ier)
+
+	case AP_CONSTANT:
+
+	    # Set the sky value to a constant.
+	    AP_SKY_MODE(sky) = AP_SKYBACKGROUND(sky)
+	    AP_SKY_SIG(sky) = AP_SKYSIGMA(nse)
+	    AP_SKY_SKEW(sky) = INDEFR
+	    AP_NSKY(sky) = 0
+	    AP_NSKY_REJECT(sky) = 0
+	    return (AP_OK)
+
+	case AP_SKYFILE:
+
+	    # Read the sky values from a file.
+	    if (sd == NULL)
+		return (AP_NOSKYFILE)
+	    ier = ap_readsky (sd, x, y, AP_SKY_MODE(sky), AP_SKY_SIG(sky),
+		AP_SKY_SKEW(sky), AP_NSKY(sky), AP_NSKY_REJECT(sky))
+	    if (ier == EOF)
+		return (AP_EOFSKYFILE)
+	    else if (ier != 7)
+		return (AP_BADSKYSCAN)
+	    else if (AP_NSKY(sky) <= 0)
+		return (AP_NOSKYAREA)
+	    else
+		return (AP_OK)
+
+	case AP_RADPLOT:
+
+	    # Check the status of the graphics stream.
+	    if (gd == NULL)
+		return (AP_NOGRAPHICS)
+
+	    # Fetch the sky pixels.
+	    ier = apskybuf (ap, im, wx, wy)
+	    if (ier != AP_OK)
+		return (ier)
+
+	    # Clip the data.
+	    if (AP_SLOCLIP(sky) > 0.0 || AP_SHICLIP(sky) > 0.0) {
+		nclip = ap_clip (Memr[AP_SKYPIX(sky)], Memi[AP_INDEX(sky)],
+		    AP_NSKYPIX(sky), AP_SLOCLIP(sky), AP_SHICLIP(sky), ilo,
+		    ihi)
+		if (nclip >= AP_NSKYPIX(sky))
+		    return (AP_NSKY_TOO_SMALL)
+		nsky = AP_NSKYPIX(sky) - nclip
+	    } else {
+		nclip = 0
+		call ap_index (Memi[AP_INDEX(sky)], AP_NSKYPIX(sky))
+		ilo = 1
+		nsky = AP_NSKYPIX(sky) 
+	    }
+
+	    # Mark the sky level on the radial profile plot.
+	    call gactivate (gd, 0)
+	    gt = ap_gtinit (AP_IMROOT(ap), wx, wy)
+	    ier = ap_radplot (gd, gt, Memr[AP_SKYPIX(sky)],
+	        Memi[AP_COORDS(sky)], Memi[AP_INDEX(sky)+ilo-1], nsky,
+		AP_SXC(sky), AP_SYC(sky), AP_SNX(sky), AP_SNY(sky),
+		AP_SCALE(ap), AP_SKY_MODE(sky), AP_SKY_SKEW(sky),
+		AP_SKY_SIG(sky), AP_NSKY(sky), AP_NSKY_REJECT(sky))
+	    AP_NSKY_REJECT(sky) = AP_NBADSKYPIX(sky) + nclip +
+	        AP_NSKY_REJECT(sky)
+	    call ap_gtfree (gt)
+	    call gdeactivate (gd, 0)
+
+	    return (ier)
+
+	case AP_HISTPLOT:
+
+	    # Check the status of the graphics stream.
+	    if (gd == NULL)
+		return (AP_NOGRAPHICS)
+
+	    # Fetch the sky pixels.
+	    ier = apskybuf (ap, im, wx, wy)
+	    if (ier != AP_OK)
+		return (ier)
+
+	    # Initialze the weights.
+	    call amovkr (1.0, Memr[AP_SWGT(sky)], AP_NSKYPIX(sky))
+
+	    # Clip the data.
+	    if (AP_SLOCLIP(sky) > 0.0 || AP_SHICLIP(sky) > 0.0) {
+		nclip = ap_clip (Memr[AP_SKYPIX(sky)], Memi[AP_INDEX(sky)],
+		    AP_NSKYPIX(sky), AP_SLOCLIP(sky), AP_SHICLIP(sky),
+		    ilo, ihi)
+		if (nclip >= AP_NSKYPIX(sky))
+		    return (AP_NSKY_TOO_SMALL)
+		nsky = AP_NSKYPIX(sky) - nclip
+	    } else {
+		nclip = 0
+		call ap_index (Memi[AP_INDEX(sky)], AP_NSKYPIX(sky))
+		ilo = 1
+		nsky = AP_NSKYPIX(sky) 
+	    }
+
+	    # Mark the peak of the histogram on the histogram plot.
+	    #call gactivate (gd, 0)
+	    gt = ap_gtinit (AP_IMROOT(ap), wx, wy)
+	    ier = ap_histplot (gd, gt, Memr[AP_SKYPIX(sky)],
+	        Memr[AP_SWGT(sky)], Memi[AP_INDEX(sky)+ilo-1], nsky,
+		AP_K1(sky), INDEFR, AP_BINSIZE(sky), AP_SMOOTH(sky),
+		AP_SKY_MODE(sky), AP_SKY_SIG(sky), AP_SKY_SKEW(sky),
+		AP_NSKY(sky), AP_NSKY_REJECT(sky))	
+	    AP_NSKY_REJECT(sky) = AP_NBADSKYPIX(sky) + nclip +
+	        AP_NSKY_REJECT(sky)
+	    call ap_gtfree (gt)
+	    #call gdeactivate (gd, 0)
+
+	    return (ier)
+
+	case AP_OFILT:
+
+	    # Fetch the sky pixels.
+	    ier = apskybuf (ap, im, wx, wy)
+	    if (ier != AP_OK)
+		return (ier)
+
+	    # Initialze the weights.
+	    call amovkr (1.0, Memr[AP_SWGT(sky)], AP_NSKYPIX(sky))
+
+	    # Clip the data.
+	    if (AP_SLOCLIP(sky) > 0.0 || AP_SHICLIP(sky) > 0.0) {
+		nclip = ap_clip (Memr[AP_SKYPIX(sky)], Memi[AP_INDEX(sky)],
+		    AP_NSKYPIX(sky), AP_SLOCLIP(sky), AP_SHICLIP(sky),
+		    ilo, ihi)
+		if (nclip >= AP_NSKYPIX(sky))
+		    return (AP_NSKY_TOO_SMALL)
+		nsky = AP_NSKYPIX(sky) - nclip
+	    } else {
+		nclip = 0
+		call ap_index (Memi[AP_INDEX(sky)], AP_NSKYPIX(sky))
+		ilo = 1
+		nsky = AP_NSKYPIX(sky) 
+	    }
+
+	    # Compute the sky value using the histogram of the sky pixels
+	    # and a variation of the optimal filtering technique.
+	    ier = ap_lgsky (Memr[AP_SKYPIX(sky)], Memi[AP_COORDS(sky)],
+	        Memr[AP_SWGT(sky)], Memi[AP_INDEX(sky)+ilo-1], nsky,
+		AP_SNX(sky), AP_SNY(sky), AP_K1(sky), INDEFR,
+		AP_BINSIZE(sky), AP_SMOOTH(sky), AP_SLOREJECT(sky),
+		AP_SHIREJECT(sky), AP_RGROW(sky) * AP_SCALE(ap),
+		AP_SMAXITER(sky), AP_SKY_MODE(sky), AP_SKY_SIG(sky),
+		AP_SKY_SKEW(sky), AP_NSKY(sky), AP_NSKY_REJECT(sky))
+	    AP_NSKY_REJECT(sky) = AP_NBADSKYPIX(sky) + nclip +
+	        AP_NSKY_REJECT(sky)
+
+	    return (ier)
+
+	case AP_GAUSS:
+
+	    # Fetch the sky pixels.
+	    ier = apskybuf (ap, im, wx, wy)
+	    if (ier != AP_OK)
+		return (ier)
+
+	    # Initialze the weights.
+	    call amovkr (1.0, Memr[AP_SWGT(sky)], AP_NSKYPIX(sky))
+
+	    # Clip the data.
+	    if (AP_SLOCLIP(sky) > 0.0 || AP_SHICLIP(sky) > 0.0) {
+		nclip = ap_clip (Memr[AP_SKYPIX(sky)], Memi[AP_INDEX(sky)],
+		    AP_NSKYPIX(sky), AP_SLOCLIP(sky), AP_SHICLIP(sky),
+		    ilo, ihi)
+		if (nclip >= AP_NSKYPIX(sky))
+		    return (AP_NSKY_TOO_SMALL)
+		nsky = AP_NSKYPIX(sky) - nclip
+	    } else {
+		nclip = 0
+		call ap_index (Memi[AP_INDEX(sky)], AP_NSKYPIX(sky))
+		ilo = 1
+		nsky = AP_NSKYPIX(sky) 
+	    }
+
+	    # Compute the sky value by a fitting a skewed Gaussian function
+	    # to the sky pixel histogram.
+	    ier = ap_gauss (Memr[AP_SKYPIX(sky)], Memi[AP_COORDS(sky)],
+	        Memr[AP_SWGT(sky)], Memi[AP_INDEX(sky)+ilo-1], nsky,
+		AP_SNX(sky), AP_SNY(sky), AP_SMAXITER(sky), AP_K1(sky),
+		INDEFR, AP_BINSIZE(sky), AP_SMOOTH(sky),
+		AP_SLOREJECT(sky), AP_SHIREJECT(sky), AP_RGROW(sky) *
+		AP_SCALE(ap), AP_SNREJECT(sky), AP_SKY_MODE(sky),
+		AP_SKY_SIG(sky), AP_SKY_SKEW(sky), AP_NSKY(sky),
+		AP_NSKY_REJECT(sky))
+	    AP_NSKY_REJECT(sky) = AP_NBADSKYPIX(sky) + nclip +
+	        AP_NSKY_REJECT(sky)
+
+	    return (ier)
+
+	case AP_CROSSCOR:
+
+	    # Fetch the sky pixels.
+	    ier = apskybuf (ap, im, wx, wy)
+	    if (ier != AP_OK)
+		return (ier)
+
+	    # Initialze the weights.
+	    call amovkr (1.0, Memr[AP_SWGT(sky)], AP_NSKYPIX(sky))
+
+	    # Clip the data.
+	    if (AP_SLOCLIP(sky) > 0.0 || AP_SHICLIP(sky) > 0.0) {
+		nclip = ap_clip (Memr[AP_SKYPIX(sky)], Memi[AP_INDEX(sky)],
+		    AP_NSKYPIX(sky), AP_SLOCLIP(sky), AP_SHICLIP(sky),
+		    ilo, ihi)
+		if (nclip >= AP_NSKYPIX(sky))
+		    return (AP_NSKY_TOO_SMALL)
+		nsky = AP_NSKYPIX(sky) - nclip
+	    } else {
+		nclip = 0
+		call ap_index (Memi[AP_INDEX(sky)], AP_NSKYPIX(sky))
+		ilo = 1
+		nsky = AP_NSKYPIX(sky) 
+	    }
+
+	    # Fit the sky value  by computing the cross-correlation
+	    # function of the histogram and an estimate of the noise
+	    # distribution.
+	    ier = ap_crosscor (Memr[AP_SKYPIX(sky)], Memi[AP_COORDS(sky)],
+	        Memr[AP_SWGT(sky)], Memi[AP_INDEX(sky)+ilo-1], nsky,
+		AP_SNX(sky), AP_SNY(sky), AP_K1(sky), INDEFR,
+		AP_BINSIZE(sky), AP_SMOOTH(sky), AP_SLOREJECT(sky),
+		AP_SHIREJECT(sky), AP_RGROW(sky) * AP_SCALE(ap),
+		AP_SMAXITER(sky), AP_SKY_MODE(sky), AP_SKY_SIG(sky),
+		AP_SKY_SKEW(sky), AP_NSKY(sky), AP_NSKY_REJECT(sky))
+	    AP_NSKY_REJECT(sky) = AP_NBADSKYPIX(sky) + nclip +
+	        AP_NSKY_REJECT(sky)
+
+	    return (ier)
+
+	default:
+
+	    AP_SKY_MODE(sky) = INDEFR
+	    AP_SKY_SIG(sky) = INDEFR
+	    AP_SKY_SKEW(sky) = INDEFR
+	    AP_NSKY(sky) = AP_NSKYPIX(sky)
+	    AP_NSKY_REJECT(sky) = 0
+	    return (AP_OK)
+	}
+end
diff --git a/noao/digiphot/apphot/fitsky/apgauss.x b/noao/digiphot/apphot/fitsky/apgauss.x
new file mode 100644
index 00000000..860301dc
--- /dev/null
+++ b/noao/digiphot/apphot/fitsky/apgauss.x
@@ -0,0 +1,296 @@
+include <mach.h>
+include <math/nlfit.h>
+include "../lib/fitsky.h"
+
+define	TOL		.001		# Fitting tolerance
+
+# AP_GAUSS -- Procedure to compute the peak, width and skew of the histogram
+# by fitting a skewed Gaussian function to the histogram.
+
+int procedure ap_gauss (skypix, coords, wgt, index, nskypix, snx, sny, maxfit,
+	k1, hwidth, binsize, smooth, losigma, hisigma, rgrow, maxiter,
+	sky_mode, sky_sigma, sky_skew, nsky, nsky_reject)
+
+real	skypix[ARB]		# array of unsorted sky pixels
+int	coords[ARB]		# array of coordinates for region growing
+real	wgt[ARB]		# weights for pixel rejection
+int	index[ARB]		# array of sort indices
+int	nskypix			# the number of sky pixels
+int	snx, sny		# the maximum dimensions of sky raster
+int	maxfit			# maximum number of iterations per fit
+real	k1			# extent of the histogram in skysigma
+real	hwidth			# width of the histogram
+real	binsize			# the size of the histogram in sky sigma
+int	smooth			# smooth the histogram before fitting
+real	losigma, hisigma	# upper and lower sigma rejection criterion
+real	rgrow			# region growing radius in pixels
+int	maxiter			# maximum number of rejection cycles
+real	sky_mode		# computed sky value
+real	sky_sigma		# computed sigma of the sky pixels
+real	sky_skew		# skew of sky pixels
+int	nsky			# number of sky pixels used in fit
+int	nsky_reject		# number of sky pixels rejected
+
+double	dsky, sumpx, sumsqpx, sumcbpx
+int	i, j, nreject, nbins, nker, ier
+pointer	sp, x, hgm, shgm, w
+real	sky_mean, sky_msigma, dmin, dmax, hmin, hmax, dh, locut, hicut, cut
+real	sky_zero
+int	ap_grow_hist2(), aphigmr()
+real	ap_asumr(), apmedr()
+
+begin
+	# Initialize.
+	nsky = nskypix
+	nsky_reject = 0
+	sky_mode = INDEFR
+	sky_sigma = INDEFR
+	sky_skew = INDEFR
+	if (nskypix <= 0)
+	    return (AP_NOSKYAREA)
+
+	# Compute initial guess for sky statistics.
+	sky_zero = ap_asumr (skypix, index, nskypix) / nskypix
+	call ap_ialimr (skypix, index, nskypix, dmin, dmax)
+	call apfimoments (skypix, index, nskypix, sky_zero, sumpx, sumsqpx,
+	    sumcbpx, sky_mean, sky_msigma, sky_skew)
+	sky_mean = apmedr (skypix, index,  nskypix)
+	sky_mean = max (dmin, min (sky_mean, dmax))
+
+	# Compute the width and bin size of the sky histogram.
+	if (! IS_INDEFR(hwidth) && hwidth > 0.0) {
+	    hmin = sky_mean - k1 * hwidth
+	    hmax = sky_mean + k1 * hwidth
+	    dh = binsize * hwidth
+	} else {
+	    cut = min (sky_mean - dmin, dmax - sky_mean, k1 * sky_msigma)
+	    hmin = sky_mean - cut
+	    hmax = sky_mean + cut
+	    dh = binsize * cut / k1
+	}
+
+	# Compute the number of histogram bins and width of smoothing kernel.
+	if (dh <= 0.0) {
+	    nbins = 1
+	    dh = 0.0
+	} else {
+	    nbins = 2 * nint ((hmax - sky_mean) / dh) + 1
+	    dh = (hmax - hmin) / (nbins - 1)
+	}
+
+	# Test for a valid histogram.
+	if (sky_msigma <= dh || dh <= 0.0 ||  k1 <= 0.0 || sky_msigma <= 0.0 ||
+	    nbins < 4) {
+	    sky_mode = sky_mean
+	    sky_sigma = 0.0
+	    sky_skew = 0.0
+	    return (AP_NOHISTOGRAM)
+	}
+
+	# Allocate temporary working space.
+	call smark (sp)
+	call salloc (x, nbins, TY_REAL)
+	call salloc (hgm, nbins, TY_REAL)
+	call salloc (shgm, nbins, TY_REAL)
+	call salloc (w, nbins, TY_REAL)
+
+	# Compute the x array.
+	do i = 1, nbins
+	    Memr[x+i-1] = i
+	call amapr (Memr[x], Memr[x], nbins, 1.0, real (nbins),
+	    hmin + 0.5 * dh, hmax + 0.5 * dh)
+
+	# Accumulate the histogram.
+	call aclrr (Memr[hgm], nbins)
+	nsky_reject = nsky_reject + aphigmr (skypix, wgt, index, nskypix,
+	    Memr[hgm], nbins, hmin, hmax)
+	nsky = nskypix - nsky_reject
+
+	# Do the initial rejection.
+	if (nsky_reject > 0) {
+	    do i = 1, nskypix {
+		if (wgt[index[i]] <= 0.0) {
+		    dsky = skypix[index[i]] - sky_zero
+		    sumpx = sumpx - dsky
+		    sumsqpx = sumsqpx - dsky ** 2
+		    sumcbpx = sumcbpx - dsky ** 3
+		}
+	    }
+	    call apmoments (sumpx, sumsqpx, sumcbpx, nsky, sky_zero,
+	        sky_mean, sky_msigma, sky_skew)
+	}
+
+	# Find the mode, sigma and skew of the histogram.
+	if (smooth == YES) {
+	    nker = max (1, nint (sky_msigma / dh))
+	    #call ap_lucy_smooth (Memr[hgm], Memr[shgm], nbins, nker, 2)
+	    call ap_bsmooth (Memr[hgm], Memr[shgm], nbins, nker, 2)
+	    call ap_hist_mode (Memr[x], Memr[shgm], Memr[w], nbins,
+		sky_mode, sky_sigma, sky_skew, maxfit, TOL, ier)
+	} else
+	    call ap_hist_mode (Memr[x], Memr[hgm], Memr[w], nbins,
+		sky_mode, sky_sigma, sky_skew, maxfit, TOL, ier)
+	sky_mode = max (dmin, min (sky_mode, dmax))
+	if (ier != AP_OK) {
+	    call sfree (sp)
+	    return (ier)
+	}
+	if ((IS_INDEFR(losigma) && IS_INDEFR(hisigma)) || sky_sigma <= dh ||
+	    maxiter < 1) {
+	    call sfree (sp)
+	    return (AP_OK)
+	}
+
+	# Fit histogram with pixel rejection and optional region growing.
+	do i = 1, maxiter {
+
+	    # Compute the new rejection limits.
+	    if (IS_INDEFR(losigma))
+		locut = -MAX_REAL
+	    else
+	        locut = sky_mode - losigma * sky_msigma
+	    if (IS_INDEFR(hisigma))
+		hicut = MAX_REAL
+	    else
+	        hicut = sky_mode + hisigma * sky_msigma
+
+	    # Detect and reject pixels.
+	    nreject = 0
+	    do j = 1, nskypix {
+		if (skypix[index[j]] >= locut && skypix[index[j]] <= hicut)
+		    next
+		if (rgrow > 0.0)
+		    nreject = nreject + ap_grow_hist2 (skypix, coords,
+			wgt, nskypix, sky_zero, index[j], snx, sny, Memr[hgm],
+			nbins, hmin, hmax, rgrow, sumpx, sumsqpx, sumcbpx)
+		else if (wgt[index[j]] > 0.0) {
+		    call ap_hgmsub2 (Memr[hgm], nbins, hmin, hmax,
+		        skypix[index[j]], sky_zero, sumpx, sumsqpx, sumcbpx)
+		    wgt[index[j]] = 0.0
+		    nreject = nreject + 1
+		}
+	    }
+	    if (nreject == 0)
+		break
+	    nsky_reject = nsky_reject + nreject
+	    nsky = nskypix - nsky_reject 
+	    if (nsky <= 0)
+		break
+	    call apmoments (sumpx, sumsqpx, sumcbpx, nsky, sky_zero,
+	        sky_mean, sky_msigma, sky_skew)
+
+	    # Recompute mean, mode, sigma and skew.
+	    if (smooth == YES) {
+		nker = max (1, nint (sky_msigma / dh))
+	        #call ap_lucy_smooth (Memr[hgm], Memr[shgm], nbins, nker, 2)
+	        call ap_bsmooth (Memr[hgm], Memr[shgm], nbins, nker, 2)
+	    	call ap_hist_mode (Memr[x], Memr[shgm], Memr[w], nbins,
+		    sky_mode, sky_sigma, sky_skew, maxfit, TOL, ier)
+	    } else
+	    	call ap_hist_mode (Memr[x], Memr[hgm], Memr[w], nbins,
+		    sky_mode, sky_sigma, sky_skew, maxfit, TOL, ier)
+	    sky_mode = max (dmin, min (sky_mode, dmax))
+	    if (ier != AP_OK)
+		break
+	    if (sky_sigma <= dh)
+		break
+	}
+
+	# Return appropriate error code.
+	call sfree (sp)
+	if (nsky == 0 || nsky_reject == nskypix) {
+	    nsky = 0
+	    nsky_reject = nskypix
+	    sky_mode = INDEFR
+	    sky_sigma = INDEFR
+	    sky_skew = INDEFR
+	    return (AP_NSKY_TOO_SMALL)
+	} else if (ier == AP_NSKY_TOO_SMALL) {
+	    return (AP_NSKY_TOO_SMALL)
+	} else if (ier != AP_OK) {
+	    return (ier)
+	} else
+	    return (AP_OK)
+end
+
+
+# AP_HIST_MODE -- Procedure to fit the skewed Gaussian function to the histogram
+# of the sky pixels.
+
+procedure ap_hist_mode (x, hgm, w, nbins, sky_mode, sky_sigma, sky_skew,
+    maxiter, tol, ier)
+
+real	x[ARB]		# x array
+real	hgm[ARB]	# histogram
+real	w[ARB]		# weights
+int	nbins		# number of bins
+real	sky_mode	# sky value
+real	sky_sigma	# sky sigma
+real	sky_skew	# sky skew
+int	maxiter		# max number of iterations
+real	tol		# tolerances
+int	ier		# error code
+
+extern  gausskew, dgausskew
+int	i, imin, imax, np, fier
+pointer	sp, list, fit, nl
+real	p[4], dp[4], dummy1
+int	locpr()
+
+begin
+	# Allocate working memory.
+	call smark (sp)
+	call salloc (list, 4, TY_INT)
+	call salloc (fit, nbins, TY_REAL)
+
+	# Initialize.
+	do i = 1, 4
+	    Memi[list+i-1] = i
+
+	# Compute initial guesses for the parameters.
+	call ap_alimr (hgm, nbins, dummy1, p[1], imin, imax)
+	p[2] = x[imax]
+	#p[3] = max (sky_sigma ** 2, abs (x[2] - x[1]) ** 2)
+	p[3] = abs ((x[nbins] - x[1]) / 6.0) ** 2
+	p[4] = 0.0
+	np = 4
+
+	# Fit the histogram.
+	call nlinitr (nl, locpr (gausskew), locpr (dgausskew), p, dp, np,
+	    Memi[list], 4, tol, maxiter)
+	call nlfitr (nl, x, hgm, w, nbins, 1, WTS_UNIFORM, fier)
+	call nlvectorr (nl, x, Memr[fit], nbins, 1)
+	call nlpgetr (nl, p, np)
+	call nlfreer (nl)
+
+	call sfree (sp)
+
+	# Return the appropriate error code.
+	ier = AP_OK
+	if (fier == NO_DEG_FREEDOM) {
+	    sky_mode = INDEFR
+	    sky_sigma = INDEFR
+	    sky_skew = INDEFR
+	    ier = AP_NSKY_TOO_SMALL
+	} else {
+	    if (fier == SINGULAR)
+		ier = AP_SKY_SINGULAR
+	    else if (fier == NOT_DONE)
+		ier = AP_SKY_NOCONVERGE
+	    if (p[2] < x[1] || p[2] > x[nbins]) {
+		sky_mode = x[imax]
+		ier = AP_BADPARAMS
+	    } else
+	        sky_mode = p[2]
+	    if (p[3] <= 0.0) {
+		sky_sigma = 0.0
+		sky_skew = 0.0
+		ier = AP_BADPARAMS
+	    } else {
+	        sky_sigma = sqrt (p[3])
+	        sky_skew = 1.743875281 * abs (p[4]) ** (1.0 / 3.0) * sky_sigma
+	        if (p[4] < 0.0)
+		    sky_skew = - sky_skew
+	    }
+	}
+end
diff --git a/noao/digiphot/apphot/fitsky/apgrowhist.x b/noao/digiphot/apphot/fitsky/apgrowhist.x
new file mode 100644
index 00000000..6f01a789
--- /dev/null
+++ b/noao/digiphot/apphot/fitsky/apgrowhist.x
@@ -0,0 +1,136 @@
+# AP_GROW_HIST -- Procedure to reject pixels with region growing.
+
+int procedure ap_grow_hist (skypix, coords, wgt, nskypix, index, snx, sny, hgm,
+    nbins, z1, z2, rgrow)
+
+real	skypix[ARB]		# sky pixels
+int	coords[ARB]		# sky pixel coordinates
+real	wgt[ARB]		# array of weights
+int	nskypix			# number of sky pixels
+int	index			# index of pixel to be rejected
+int	snx, sny		# size of sky subraster
+real	hgm[ARB]		# histogram
+int	nbins			# number of bins
+real	z1, z2			# value of first and last histogram bin
+real	rgrow			# region growing radius
+
+int	j, k, ixc, iyc, ymin, ymax, xmin, xmax, nreject, cstart, c, bin
+real	dh, r2, rgrow2, d
+
+begin
+	# Find the x and y coordinates of the pixel to be rejected.
+	ixc = mod (coords[index], snx)
+	if (ixc == 0)
+	    ixc = snx
+	iyc = (coords[index] - ixc) / snx + 1
+
+	# Find the coordinate space to be used for regions growing.
+	ymin = max (1, int (iyc - rgrow))
+	ymax = min (sny, int (iyc + rgrow))
+	xmin = max (1, int (ixc - rgrow))
+	xmax = min (snx, int (ixc + rgrow))
+	if (ymin <= iyc)
+	    cstart = min (nskypix, max (1, index - int (rgrow) + snx *
+	        (ymin - iyc)))
+	else
+	    cstart = index
+
+	# Perform the region growing.
+	dh = real (nbins - 1) / (z2 - z1)
+	rgrow2 = rgrow ** 2
+	nreject = 0
+	do j = ymin, ymax {
+	    d = rgrow2 - (j - iyc) ** 2
+	    if (d <= 0.0)
+		d = 0.0
+	    else
+		d = sqrt (d)
+	    do k = max (xmin, int (ixc - d)), min (xmax, int (ixc + d)) {
+		c = k + (j - 1) * snx
+		while (coords[cstart] < c && cstart < nskypix)
+		    cstart = cstart + 1
+		r2 = (k - ixc) ** 2 + (j - iyc) ** 2
+		if (r2 <= rgrow2 && c == coords[cstart] && wgt[cstart] > 0.0) {
+		    nreject = nreject + 1
+		    wgt[cstart] = 0.0
+		    if (skypix[cstart] >= z1 && skypix[cstart] <= z2) {
+		        bin = int ((skypix[cstart] - z1) * dh) + 1
+		        hgm[bin] = hgm[bin] - 1.0
+		    }
+		}
+	    }
+	}
+
+	return (nreject)
+end
+
+
+# AP_GROW_HIST2 -- Procedure to reject pixels with region growing.
+
+int procedure ap_grow_hist2 (skypix, coords, wgt, nskypix, sky_zero, index,
+    snx, sny, hgm, nbins, z1, z2, rgrow, sumpx, sumsqpx, sumcbpx)
+
+real	skypix[ARB]		# sky pixels
+int	coords[ARB]		# coordinates
+real	wgt[ARB]		# array of weights
+int	nskypix			# number of sky pixels
+real	sky_zero		# the sky zero point for moment analysis
+int	index			# index of pixel to be rejected
+int	snx, sny		# size of sky subraster
+real	hgm[ARB]		# histogram
+int	nbins			# number of bins
+real	z1, z2			# value of first and last histogram bin
+real	rgrow			# region growing radius
+double	sumpx			# sum of sky values
+double	sumsqpx			# sum of sky values squared
+double	sumcbpx			# sum of sky values cubed
+
+double	dsky
+int	j, k, ixc, iyc, ymin, ymax, xmin, xmax, nreject, cstart, c, bin
+real	dh, r2, rgrow2, d
+
+begin
+	# Find the coordinates of the region growing center.
+	ixc = mod (coords[index], snx)
+	if (ixc == 0)
+	    ixc = snx
+	iyc = (coords[index] - ixc) / snx + 1
+
+	ymin = max (1, int (iyc - rgrow))
+	ymax = min (sny, int (iyc + rgrow))
+	xmin = max (1, int (ixc - rgrow))
+	xmax = min (snx, int (ixc + rgrow))
+	dh = real (nbins - 1) / (z2 - z1)
+	if (ymin <= iyc)
+	    cstart = min (nskypix, max (1, index - int (rgrow) + snx *
+	        (ymin - iyc)))
+	else
+	    cstart = index
+
+	# Perform the region growing.
+	nreject = 0
+	rgrow2 = rgrow ** 2
+	do j = ymin, ymax {
+	    d = sqrt (rgrow2 - (j - iyc) ** 2)
+	    do k = max (xmin, int (ixc - d)), min (xmax, int (ixc + d)) {
+		c = k + (j - 1) * snx
+		while (coords[cstart] < c && cstart < nskypix)
+		    cstart = cstart + 1
+		r2 = (k - ixc) ** 2 + (j - iyc) ** 2
+		if (r2 <= rgrow2 && c == coords[cstart] && wgt[cstart] > 0.0) {
+		    nreject = nreject + 1
+		    wgt[cstart] = 0.0
+		    dsky = skypix[cstart] - sky_zero
+		    sumpx = sumpx - dsky
+		    sumsqpx = sumsqpx - dsky ** 2
+		    sumcbpx = sumcbpx - dsky ** 3
+		    if (skypix[cstart] >= z1 && skypix[cstart] <= z2) {
+		        bin = int ((skypix[cstart] - z1) * dh) + 1
+		        hgm[bin] = hgm[bin] - 1.0
+		    }
+		}
+	    }
+	}
+
+	return (nreject)
+end
diff --git a/noao/digiphot/apphot/fitsky/apgspars.x b/noao/digiphot/apphot/fitsky/apgspars.x
new file mode 100644
index 00000000..8ca7f52c
--- /dev/null
+++ b/noao/digiphot/apphot/fitsky/apgspars.x
@@ -0,0 +1,26 @@
+include "../lib/display.h"
+include "../lib/noise.h"
+include "../lib/fitsky.h"
+
+# AP_SGPARS -- Procedure to fetch the parameters for the fitsky task.
+
+procedure ap_sgpars (ap)
+
+pointer	ap		# pointer to apphot structure
+
+bool	clgetb()
+int	btoi()
+
+begin
+	# Open the apphot structure.
+	call apsinit (ap, AP_MODE, 10.0, 10.0, 2.0, AP_NPOISSON)
+
+	# Get the data dependent parameters.
+	call ap_gdapars (ap)
+
+	# Get the sky fitting parameters.
+	call ap_gsapars (ap)
+
+	# Get radial plots.
+	call apseti (ap, RADPLOTS, btoi (clgetb ("radplots")))
+end
diff --git a/noao/digiphot/apphot/fitsky/aphgmsub.x b/noao/digiphot/apphot/fitsky/aphgmsub.x
new file mode 100644
index 00000000..ae969bba
--- /dev/null
+++ b/noao/digiphot/apphot/fitsky/aphgmsub.x
@@ -0,0 +1,51 @@
+# AP_HGMSUB -- Procedure to subtract a point from an existing  histogram.
+
+procedure ap_hgmsub (hgm, nbins, z1, z2, skypix)
+
+real	hgm[ARB]		# histogram
+int	nbins			# number of bins
+real	z1, z2			# range of histogram
+real	skypix	               	# sky value
+
+int	bin
+real	dh
+
+begin
+	if (skypix < z1 || skypix > z2)
+	    return
+	dh = real (nbins - 1) / (z2 - z1)
+	bin = int ((skypix - z1) * dh) + 1
+	hgm[bin] = hgm[bin] - 1.0
+end
+
+
+# AP_HGMSUB2 -- Procedure to subract points from the accumulated sums
+# and the existing histogram.
+
+procedure ap_hgmsub2 (hgm, nbins, z1, z2, skypix, sky_zero, sumpx, sumsqpx,
+	sumcbpx)
+
+real	hgm[ARB]		# histogram
+int	nbins			# number of bins
+real	z1, z2			# range of histogram
+real	skypix	               	# sky value
+real	sky_zero		# sky zero point for moment analysis
+double	sumpx			# sum of the sky pixel values
+double	sumsqpx			# sum of the squares of the sky pixel values
+double	sumcbpx			# sum of the cubes of the sky pixel values
+
+double	dsky
+int	bin
+real	dh
+
+begin
+	if (skypix < z1 || skypix > z2)
+	    return
+	dsky = skypix - sky_zero
+	sumpx = sumpx - dsky
+	sumsqpx = sumsqpx - dsky ** 2
+	sumcbpx = sumcbpx - dsky ** 3
+	dh = real (nbins - 1) / (z2 - z1)
+	bin = int ((skypix - z1) * dh) + 1
+	hgm[bin] = hgm[bin] - 1.0
+end
diff --git a/noao/digiphot/apphot/fitsky/aphistplot.x b/noao/digiphot/apphot/fitsky/aphistplot.x
new file mode 100644
index 00000000..49c00071
--- /dev/null
+++ b/noao/digiphot/apphot/fitsky/aphistplot.x
@@ -0,0 +1,233 @@
+include <gset.h>
+include <pkg/gtools.h>
+include "../lib/fitsky.h"
+
+# AP_HISTPLOT -- Procedure to the sky value using a plot of the sky histogram
+# and cursor readback.
+
+int procedure ap_histplot (gd, gt, skypix, wgt, index, nskypix, k1, hwidth,
+	binsize, smooth, sky_mode, sky_sigma, sky_skew, nsky, nsky_reject)
+
+pointer	gd			# pointer to graphics stream
+pointer	gt			# pointer to GTOOLS structure
+real	skypix[ARB]		# array of unsorted sky pixels
+real	wgt[ARB]		# array of weights for rejection
+int	index[ARB]		# array of sort indices
+int	nskypix			# number of sky pixels
+real	k1			# rejection criterion
+real	hwidth			# half width of histogram in k1 units
+real	binsize			# histogram binsize in units of sigma
+int	smooth			# smooth the histogram
+real	sky_mode		# sky value
+real	sky_sigma		# sigma of sky pixels
+real	sky_skew		# skew of sky pixels
+int	nsky			# number of sky pixels
+int	nsky_reject		# number of rejected sky pixels
+
+double	dsky, sumpx, sumsqpx, sumcbpx
+int	i, nbins, nker, wcs, key
+pointer	sp, x, hgm, shgm, cmd
+real	dmin, dmax, hmin, hmax, dh, ymin, ymax, symin, symax, wx, wy
+real	u1, u2, v1, v2, x1, x2, y1, y2, cut, sky_mean, sky_zero
+int	clgcur(), aphigmr()
+real	apmedr(), ap_asumr()
+
+begin
+	# Check for valid graphics stream.
+	if (gd == NULL)
+	    return (AP_NOGRAPHICS)
+
+	# Initialize.
+	nsky = nskypix
+	nsky_reject = 0
+	sky_mode = INDEFR
+	sky_sigma = INDEFR
+	sky_skew = INDEFR
+	if (nskypix <= 0)
+	    return (AP_SKY_OUTOFBOUNDS)
+
+	# Compute an initial guess at the sky distribution.
+	sky_zero = ap_asumr (skypix, index, nskypix) / nskypix
+	call ap_ialimr (skypix, index, nskypix, dmin, dmax)
+	call apfimoments (skypix, index, nskypix, sky_zero, sumpx, sumsqpx,
+	    sumcbpx, sky_mean, sky_sigma, sky_skew)
+	sky_mode = apmedr (skypix, index, nskypix)
+	sky_mode = max (dmin, min (sky_mode, dmax))
+
+	# Compute histogram width and binsize.
+	if (! IS_INDEFR(hwidth) && hwidth > 0.0) {
+	    hmin = sky_mode - k1 * hwidth
+	    hmax = sky_mode + k1 * hwidth
+	    dh = binsize * hwidth
+	} else {
+	    cut = min (sky_mode - dmin, dmax - sky_mode, k1 * sky_sigma)
+	    hmin = sky_mode - cut
+	    hmax = sky_mode + cut
+	    dh = binsize * cut / k1
+	}
+
+	# Compute the number of histgram bins and the histogram resolution.
+	if (dh <= 0.0) {
+	    nbins = 1
+	    dh = 0.0
+	} else {
+	    nbins = 2 * nint ((hmax - sky_mode) / dh) + 1
+	    dh = (hmax - hmin) / (nbins - 1)
+	}
+
+	# Test for a valid histogram.
+	if (dh <= 0.0 || k1 <= 0.0 || sky_sigma <= 0.0 || sky_sigma <= dh ||
+	    nbins < 2) {
+	    sky_mode = sky_mode
+	    sky_sigma = 0.0
+	    sky_skew = 0.0
+	    return (AP_NOHISTOGRAM)
+	}
+
+	# Allocate temporary space.
+	call smark (sp)
+	call salloc (x, nbins, TY_REAL)
+	call salloc (hgm, nbins, TY_REAL)
+	call salloc (shgm, nbins, TY_REAL)
+	call salloc (cmd, SZ_LINE, TY_CHAR)
+
+	# Compute the x array and accumulate the histogram.
+	do i = 1, nbins
+	    Memr[x+i-1] = i
+	call amapr (Memr[x], Memr[x], nbins, 1.0, real (nbins),
+	    hmin + 0.5 * dh, hmax + 0.5 * dh) 
+	call aclrr (Memr[hgm], nbins)
+	nsky_reject = nsky_reject + aphigmr (skypix, wgt, index, nskypix,
+	    Memr[hgm], nbins, hmin, hmax)
+	nsky = nskypix - nsky_reject
+
+	# Subtract rejected pixels and recompute the moments.
+	if (nsky_reject > 0) {
+	    do i = 1, nskypix {
+	        if (wgt[index[i]] <= 0.0) {
+		    dsky = skypix[index[i]] - sky_zero
+		    sumpx = sumpx - dsky
+		    sumsqpx = sumsqpx - dsky ** 2
+		    sumcbpx = sumcbpx - dsky ** 3
+	        }
+	    }
+	}
+	call apmoments (sumpx, sumsqpx, sumcbpx, nsky, sky_zero, sky_mean,
+	    sky_sigma, sky_skew)
+
+	# Smooth the histogram and compute the histogram plot limits.
+	if (smooth == YES) {
+	    nker = max (1, nint (sky_sigma / dh))
+	    #call ap_lucy_smooth (Memr[hgm], Memr[shgm], nbins, nker, 2)
+	    call ap_bsmooth (Memr[hgm], Memr[shgm], nbins, nker, 2)
+	    call alimr (Memr[hgm], nbins, ymin, ymax)
+	    call alimr (Memr[shgm], nbins, symin, symax)
+	    ymin = min (ymin, symin)
+	    ymax = max (ymax, symax)
+	} else
+	    call alimr (Memr[hgm], nbins, ymin, ymax)
+
+	# Store the old viewport and window coordinates.
+	call greactivate (gd, 0)
+	call ggview (gd, u1, u2, v1, v2)
+	call ggwind (gd, x1, x2, y1, y2)
+
+	# Plot the raw and smoothed histograms.
+	call ap_set_hplot (gd, gt, hmin, hmax, ymin, ymax, nbins, smooth)
+	if (smooth == YES) {
+	    call ap_plothist (gd, gt, Memr[x], Memr[hgm], nbins, "histogram",
+	        GL_SOLID)
+	    call ap_plothist (gd, gt, Memr[x], Memr[shgm], nbins, "line",
+	        GL_SOLID)
+	} else
+	    call ap_plothist (gd, gt, Memr[x], Memr[hgm], nbins, "histogram",
+	        GL_SOLID)
+
+	# Mark the peak of the histogram with the cursor.
+	call printf (
+	    "Mark histogram peak (%g) [space=mark,q=quit,:.help=help:]")
+	    call pargr (sky_mode)
+	call gscur (gd, sky_mode, (ymin + ymax) / 2.0)
+	while (clgcur ("gcommands", wx, wy, wcs, key, Memc[cmd], SZ_LINE) !=
+	    EOF) {
+		if (key == 'q')
+		    break
+		else
+		    sky_mode = max (hmin, min (wx, hmax))
+	    call printf (
+	        "Mark histogram peak (%g) [space=mark,q=quit,:.help=help:]")
+	        call pargr (sky_mode)
+	}
+
+	# Store the old viewport and window coordinates.
+	call gsview (gd, u1, u2, v1, v2)
+	call gswind (gd, x1, x2, y1, y2)
+
+	# Close up.
+	call gflush (gd)
+	call gdeactivate (gd, 0)
+	call sfree (sp)
+	return (AP_OK)
+end
+
+
+# AP_PLOTHIST -- Procedure plot the histogram.
+
+procedure ap_plothist (gd, gt, x, hgm, nbins, plottype, polytype) 
+
+pointer	gd		# pointer to graphics stream
+pointer	gt		# GTOOLS pointer
+real	x[ARB]		# the histogram bin values
+real	hgm[ARB]	# histogram
+int	nbins		# number of bins
+char	plottype[ARB]	# the plot type "histogram" or "line"
+int	polytype	# polyline type
+
+begin
+	call gt_sets (gt, GTTYPE, plottype)
+	call gt_seti (gt, GTLINE, polytype)
+	call gt_plot (gd, gt, x, hgm, nbins)
+	call gflush (gd)
+end
+
+
+# AP_SET_HPLOT -- Procedure to set up the histogram plot.
+
+procedure ap_set_hplot (gd, gt, xmin, xmax, ymin, ymax, nbins, smooth)
+
+pointer	gd		# pointer to GRAPHICS stream
+pointer	gt		# pointer to GTOOLS structure
+real	xmin, xmax	# min and max of x vector
+real	ymin, ymax	# min and max of y vector
+int	nbins		# number of bins
+int	smooth		# smooth histogram
+
+pointer	sp, str
+
+begin
+	# Initialize
+	call gclear (gd)
+	call smark (sp)
+	call salloc (str, SZ_LINE, TY_CHAR)
+
+	# Set up the gtools parameter string.
+	call sprintf (Memc[str], SZ_LINE,
+	    "Sky Histogram: nbins = %d hmin = %g hmax = %g smooth=%b")
+	    call pargi (nbins)
+	    call pargr (xmin)
+	    call pargr (xmax)
+	    call pargi (smooth)
+	call gt_sets (gt, GTPARAMS, Memc[str])
+
+	# Set up the plot axes.
+	call gt_sets (gt, GTXLABEL, "Sky Values")
+	call gt_sets (gt, GTYLABEL, "Number of Pixels")
+	call gt_setr (gt, GTXMIN, xmin)
+	call gt_setr (gt, GTXMAX, xmax)
+	call gt_setr (gt, GTYMIN, ymin)
+	call gt_setr (gt, GTYMAX, ymax)
+	call gt_swind (gd, gt)
+	call gt_labax (gd, gt)
+
+	call sfree (sp)
+end
diff --git a/noao/digiphot/apphot/fitsky/aplgsky.x b/noao/digiphot/apphot/fitsky/aplgsky.x
new file mode 100644
index 00000000..db5b4a19
--- /dev/null
+++ b/noao/digiphot/apphot/fitsky/aplgsky.x
@@ -0,0 +1,216 @@
+include <mach.h>
+include "../lib/fitsky.h"
+
+define	TOL		0.001		# Fitting tolerance
+
+# AP_LGSKY -- Procedure to fit the peak and width of the histogram using
+# repeated convolutions and a triangle function.
+
+int procedure ap_lgsky (skypix, coords, wgt, index, nskypix, snx, sny, k1,
+	hwidth, binsize, smooth, losigma, hisigma, rgrow, maxiter, sky_mode,
+	sky_sigma, sky_skew, nsky, nsky_reject)
+
+real	skypix[ARB]		# array of sky pixels
+int	coords[ARB]		# array of coordinates of region growing
+real	wgt[ARB]		# array of weights for rejection
+int	index[ARB]		# array of sort indices
+int	nskypix			# the number of sky pixels
+int	snx, sny		# the maximum dimensions of sky raster
+real	k1			# extent of the histogram in skysigma
+real	hwidth			# width of histogram
+real	binsize			# the size of the histogram in sky sigma
+int	smooth			# smooth the histogram before fitting
+real	losigma, hisigma	# upper and lower sigma rejection limits
+real	rgrow			# region growing radius in pixels
+int	maxiter			# maximum number of rejection cycles
+real	sky_mode		# computed sky value
+real	sky_sigma		# computed sigma of the sky pixels
+real	sky_skew		# skew of sky pixels
+int	nsky			# number of sky pixels used in fit
+int	nsky_reject		# number of sky pixels rejected
+
+double 	dsky, sumpx, sumsqpx, sumcbpx
+int	nreject, nbins, nker, i, j, iter
+pointer	sp, hgm, shgm
+real	dmin, dmax, hmin, hmax, dh, locut, hicut, sky_mean, center, cut
+real	sky_zero
+int	ap_grow_hist2(), aphigmr(), aptopt()
+real	ap_asumr(), apmedr(), apmapr()
+
+begin
+	# Initialize.
+	nsky = nskypix
+	nsky_reject = 0
+	sky_mode = INDEFR
+	sky_sigma = INDEFR
+	sky_skew = INDEFR
+	if (nskypix <= 0)
+	    return (AP_NOSKYAREA)
+
+	# Compute a first guess for the parameters.
+	sky_zero = ap_asumr (skypix, index, nskypix) / nskypix
+	call ap_ialimr (skypix, index, nskypix, dmin, dmax)
+	call apfimoments (skypix, index, nskypix, sky_zero, sumpx, sumsqpx,
+	    sumcbpx, sky_mean, sky_sigma, sky_skew)
+	sky_mean = apmedr (skypix, index, nskypix)
+	sky_mean = max (dmin, min (sky_mean, dmax))
+
+	# Compute the width and bin size of histogram.
+	if (! IS_INDEFR(hwidth) && hwidth > 0.0) {
+	    hmin = sky_mean - k1 * hwidth
+	    hmax = sky_mean + k1 * hwidth
+	    dh = binsize * hwidth
+	} else {
+	    cut = min (sky_mean - dmin, dmax - sky_mean, k1 * sky_sigma)
+	    hmin = sky_mean - cut
+	    hmax = sky_mean + cut
+	    dh = binsize * cut / k1
+	}
+
+	# Compute the number of histogram bins and the resolution.
+	# filter.
+	if (dh <= 0.0) {
+	    nbins = 1
+	    dh = 0.0
+	} else {
+	    nbins = 2 * nint ((hmax - sky_mean) / dh) + 1
+	    dh  = (hmax - hmin) / (nbins - 1)
+	}
+
+	# Test for a valid histogram.
+	if (nbins < 2 || k1 <= 0.0 || sky_sigma <= 0.0 || dh <= 0.0 ||
+	    sky_sigma <= dh) {
+	    sky_mode = sky_mean
+	    sky_sigma = 0.0
+	    sky_skew = 0.0
+	    return (AP_NOHISTOGRAM)
+	}
+
+	# Allocate temporary space.
+	call smark (sp)
+	call salloc (hgm, nbins, TY_REAL)
+	call salloc (shgm, nbins, TY_REAL)
+
+	# Accumulate the histogram.
+	call aclrr (Memr[hgm], nbins)
+	nsky_reject = nsky_reject + aphigmr (skypix, wgt, index, nskypix,
+	    Memr[hgm], nbins, hmin, hmax)
+	nsky = nskypix - nsky_reject
+
+	# Perform the initial rejection.
+	if (nsky_reject > 0) {
+	    do i = 1, nskypix {
+	        if (wgt[index[i]] <= 0.0) {
+		    dsky = skypix[index[i]] - sky_zero
+		    sumpx = sumpx - dsky
+		    sumsqpx = sumsqpx - dsky ** 2
+		    sumcbpx = sumcbpx - dsky ** 3
+		}
+	    }
+	    call apmoments (sumpx, sumsqpx, sumcbpx, nsky, sky_zero,
+	        sky_mean, sky_sigma, sky_skew)
+	}
+
+	# Fit the peak of the histogram.
+	center = apmapr ((hmin + hmax) / 2.0, hmin + 0.5 * dh,
+	    hmax + 0.5 * dh, 1.0, real (nbins))
+	if (smooth == YES) {
+	    nker = max (1, nint (sky_sigma / dh))
+	    #call ap_lucy_smooth (Memr[hgm], Memr[shgm], nbins, nker, 2)
+	    call ap_bsmooth (Memr[hgm], Memr[shgm], nbins, nker, 2)
+	    iter =  aptopt (Memr[shgm], nbins, center, sky_sigma / dh,
+	        TOL, maxiter, NO)
+	} else
+	    iter = aptopt (Memr[hgm], nbins, center, sky_sigma / dh, TOL,
+	        maxiter, NO)
+	sky_mode = apmapr (center, 1.0, real (nbins), hmin + 0.5 * dh,
+	    hmax + 0.5 * dh)
+	sky_mode = max (dmin, min (sky_mode, dmax))
+	if (iter < 0) {
+	    call sfree (sp)
+	    return (AP_SKY_NOCONVERGE)
+	}
+	if ((IS_INDEFR(losigma) && IS_INDEFR(hisigma)) || (sky_sigma <= dh) ||
+	    (maxiter < 1)) {
+	    call sfree (sp)
+	    return (AP_OK)
+	}
+
+	# Fit the histogram with pixel rejection and optional region growing.
+	do i = 1, maxiter {
+
+	    # Compute new histogram limits.
+	    if (IS_INDEFR(losigma))
+		locut = -MAX_REAL
+	    else
+	        locut = sky_mode - losigma * sky_sigma
+	    if (IS_INDEFR(hisigma))
+		hicut = MAX_REAL
+	    else
+	        hicut = sky_mode + hisigma * sky_sigma
+
+	    # Detect and reject the pixels.
+	    nreject = 0
+	    do j = 1, nskypix {
+		if (skypix[index[j]] >= locut && skypix[index[j]] <= hicut)
+		    next
+		if (rgrow > 0.0)
+		    nreject = nreject + ap_grow_hist2 (skypix, coords,
+			wgt, nskypix, sky_zero, index[j], snx, sny, Memr[hgm],
+			nbins, hmin, hmax, rgrow, sumpx, sumsqpx, sumcbpx)
+		else if (wgt[index[j]] > 0.0) {
+		    call ap_hgmsub2 (Memr[hgm], nbins, hmin, hmax,
+		        skypix[index[j]], sky_zero, sumpx, sumsqpx, sumcbpx)
+		    wgt[index[j]] = 0.0
+		    nreject = nreject + 1
+		}
+	    }
+	    if (nreject == 0)
+		break
+
+	    # Recompute the data limits.
+	    nsky_reject = nsky_reject + nreject
+	    nsky = nskypix - nsky_reject 
+	    if (nsky <= 0)
+		break
+	    call apmoments (sumpx, sumsqpx, sumcbpx, nsky, sky_zero,
+	        sky_mean, sky_sigma, sky_skew)
+	    if (sky_sigma <= dh)
+		break
+
+	    # Refit the sky.
+	    if (smooth == YES) {
+		nker = max (1, nint (sky_sigma / dh))
+	        #call ap_lucy_smooth (Memr[hgm], Memr[shgm], nbins, nker, 2)
+	        call ap_bsmooth (Memr[hgm], Memr[shgm], nbins, nker, 2)
+	    	iter = aptopt (Memr[shgm], nbins, center, sky_sigma / dh,
+		    TOL, maxiter, NO)
+	    } else
+	    	iter = aptopt (Memr[hgm], nbins, center, sky_sigma / dh,
+		    TOL, maxiter, NO)
+	    sky_mode = apmapr (center, 1.0, real (nbins), hmin + 0.5 * dh,
+	        hmax + 0.5 * dh)
+	    sky_mode = max (dmin, min (sky_mode, dmax))
+	    if (iter < 0) 
+		break
+	}
+
+	# Return an appropriate error code.
+	call sfree (sp)
+	if (nsky == 0 || nsky_reject == nskypix) {
+	    nsky = 0
+	    nsky_reject = nskypix
+	    sky_mode = INDEFR
+	    sky_sigma = INDEFR
+	    sky_skew = INDEFR
+	    return (AP_NSKY_TOO_SMALL)
+	} else if (sky_sigma <= 0.0) {
+	    sky_sigma = 0.0
+	    sky_skew = 0.0
+	    return (AP_OK)
+	} else if (iter < 0) {
+	    return (AP_SKY_NOCONVERGE)
+	} else {
+	    return (AP_OK)
+	}
+end
diff --git a/noao/digiphot/apphot/fitsky/apmean.x b/noao/digiphot/apphot/fitsky/apmean.x
new file mode 100644
index 00000000..f134f02c
--- /dev/null
+++ b/noao/digiphot/apphot/fitsky/apmean.x
@@ -0,0 +1,120 @@
+include <mach.h>
+include "../lib/fitsky.h"
+
+# AP_MEAN -- Procedure to calculate the mean of the sky pixel array.
+
+int procedure ap_mean (skypix, coords, wgt, index, nskypix, snx, sny, losigma,
+	hisigma, rgrow, maxiter, sky_mean, sky_sigma, sky_skew, nsky,
+	nsky_reject)
+
+real	skypix[ARB]		# unsorted array of skypixels
+int	coords[ARB]		# coordinate array for region growing
+real	wgt[ARB]		# the weight array for rejection
+int	index[ARB]		# sorted array of indices
+int	nskypix			# total number of sky pixels
+int	snx, sny		# dimensions of the sky subraster
+real	losigma, hisigma	# number of sky_sigma for rejection
+real	rgrow			# radius of region growing
+int	maxiter			# maximum number of cycles of rejection
+real	sky_mean		# computed sky value
+real	sky_sigma		# the computed sky sigma
+real	sky_skew		# skewness of sky distribution
+int	nsky			# the number of sky pixels used
+int	nsky_reject		# the number of sky pixels rejected
+
+double  dsky, sumpx, sumsqpx, sumcbpx
+int	i, j, nreject
+real	sky_zero, dmin, dmax, locut, hicut
+int	ap_grow_regions()
+real	ap_asumr()
+
+begin
+	# Intialize.
+	nsky = nskypix
+	nsky_reject = 0
+	sky_mean = INDEFR
+	sky_sigma = INDEFR
+	sky_skew = INDEFR
+	if (nskypix <= 0)
+	    return (AP_NOSKYAREA)
+
+	# Compute the mean, sigma and skew.
+	sky_zero = ap_asumr (skypix, index, nskypix) / nskypix
+	call apfimoments (skypix, index, nskypix, sky_zero, sumpx, sumsqpx,
+	    sumcbpx, sky_mean, sky_sigma, sky_skew)
+	call ap_ialimr (skypix, index, nskypix, dmin, dmax)
+	sky_mean = max (dmin, min (sky_mean, dmax))
+
+	# Decide whether to do the rejection cycle.
+	if (maxiter < 1 || (IS_INDEFR(losigma) && IS_INDEFR(hisigma)) ||
+	    sky_sigma <= 0.0)
+	    return (AP_OK)
+
+	# Reject points within k1 * sky_sigma of the median.
+	do i = 1, maxiter {
+
+	    # Compute the new rejection limits.
+	    if (IS_INDEFR(losigma))
+		locut = max (-MAX_REAL, dmin)
+	    else if (i == 1)
+		locut = sky_mean -  min (sky_mean - dmin, dmax - sky_mean,
+		    losigma * sky_sigma)
+	    else
+	        locut = sky_mean - losigma * sky_sigma
+	    if (IS_INDEFR(hisigma))
+		hicut = min (MAX_REAL, dmax)
+	    else if (i == 1)
+		hicut = sky_mean + min (dmax - sky_mean, sky_mean - dmin,
+		    hisigma * sky_sigma)
+	    else
+	        hicut = sky_mean + hisigma * sky_sigma
+
+	    nreject = 0
+	    do j = 1, nskypix {
+	        if (wgt[index[j]] <= 0.0)
+		    next
+	        if (skypix[index[j]] < locut || skypix[index[j]] > hicut) {
+		    if (rgrow > 0.0) {
+		        nreject = ap_grow_regions (skypix, coords, wgt,
+			    nskypix, sky_zero, index[j], snx, sny, rgrow,
+			    sumpx, sumsqpx, sumcbpx)
+		    } else {
+			dsky = (skypix[index[j]] - sky_zero)
+		        sumpx = sumpx - dsky
+		        sumsqpx = sumsqpx - dsky ** 2
+		        sumcbpx = sumcbpx - dsky ** 3
+		        wgt[index[j]] = 0.0 
+		        nreject = nreject + 1
+		    }
+	        }
+	    }
+
+	    # Test the number of rejected pixels.
+	    if (nreject <= 0)
+		break
+	    nsky_reject = nsky_reject + nreject
+
+	    # Test that some pixels actually remain.
+	    nsky = nskypix - nsky_reject
+	    if (nsky <= 0)
+		break
+
+	    # Recompute the mean, sigma and skew.
+	    call apmoments (sumpx, sumsqpx, sumcbpx, nsky, sky_zero,
+	        sky_mean, sky_sigma, sky_skew)
+	    if (sky_sigma <= 0.0)
+		break
+	    sky_mean = max (dmin, min (sky_mean, dmax))
+	}
+
+	# Return an appropriate error code.
+	if (nsky == 0 || nsky_reject == nskypix) {
+	    nsky = 0
+	    nsky_reject = nskypix
+	    sky_mean = INDEFR
+	    sky_sigma = INDEFR
+	    sky_skew = INDEFR
+	    return (AP_NSKY_TOO_SMALL)
+	} else
+	    return (AP_OK)
+end
diff --git a/noao/digiphot/apphot/fitsky/apmedian.x b/noao/digiphot/apphot/fitsky/apmedian.x
new file mode 100644
index 00000000..5998492c
--- /dev/null
+++ b/noao/digiphot/apphot/fitsky/apmedian.x
@@ -0,0 +1,184 @@
+include <mach.h>
+include "../lib/fitsky.h"
+
+define	MEDCUT	0.025
+
+# AP_MEDIAN -- Procedure to calculate the median of the sky pixel array.
+
+int procedure ap_median (skypix, coords, wgt, index, nskypix, snx, sny, losigma,
+	hisigma, rgrow, maxiter, sky_med, sky_sigma, sky_skew, nsky,
+	nsky_reject)
+
+real	skypix[ARB]		# unsorted array of sky pixels
+int	coords[ARB]		# coordinate array for regions growing
+real	wgt[ARB]		# array of weights for rejections
+int	index[ARB]		# sky pixel indices in sort order
+int	nskypix			# total number of sky pixels
+int	snx, sny		# dimensions of the sky subraster
+real	losigma, hisigma	# upper and lower sigma for rejection
+real	rgrow			# radius of region growing
+int	maxiter			# maximum number of cycles of rejection
+real	sky_med			# computed sky value
+real	sky_sigma		# the computed sky sigma
+real	sky_skew		# skewness of sky distribution
+int	nsky			# the number of sky pixels used
+int	nsky_reject		# the number of sky pixels rejected
+
+double  dsky, sumpx, sumsqpx, sumcbpx
+int	i, j, ilo, ihi, il, ih, med, medcut
+real	sky_zero, sky_mean, locut, hicut, dmin, dmax
+int	ap_grow_regions(), apimed()
+real	apsmed(), apwsmed(), ap_asumr()
+
+begin
+	# Intialize.
+	nsky = nskypix
+	nsky_reject = 0
+	sky_med = INDEFR
+	sky_sigma = INDEFR
+	sky_skew = INDEFR
+	if (nskypix <= 0)
+	    return (AP_NOSKYAREA)
+
+	# Sort the sky pixels and compute the median, mean, sigma and skew.
+	# MEDCUT tries to correct for quantization effects
+	call ap_ialimr (skypix, index, nskypix, dmin, dmax)
+	sky_zero = ap_asumr (skypix, index, nskypix) / nskypix
+	medcut = nint (MEDCUT * real (nskypix))
+	sky_med = apsmed (skypix, index, nskypix, medcut)
+	sky_med = max (dmin, min (sky_med, dmax))
+	call apfimoments (skypix, index, nskypix, sky_zero, sumpx, sumsqpx,
+	    sumcbpx, sky_mean, sky_sigma, sky_skew)
+	sky_mean = max (dmin, min (sky_mean, dmax))
+	if (maxiter < 1 || (IS_INDEFR(losigma) && IS_INDEFR(hisigma)) ||
+	    sky_sigma <= 0.0)
+	    return (AP_OK)
+	#call printf (
+	    #"mean=%g med=%g sigma=%g nsky=%d nrej=%d dmin=%g dmax=%g\n")
+	    #call pargr (sky_mean)
+	    #call pargr (sky_med)
+	    #call pargr (sky_sigma)
+	    #call pargi (nsky)
+	    #call pargi (nsky_reject)
+	    #call pargr (dmin)
+	    #call pargr (dmax)
+
+	# Reject points outside losigma * sky_sigma and hisigma * sky_sigma
+	# of the median.
+	ilo = 1
+	ihi = nskypix
+	do i = 1, maxiter {
+
+	    # Compute the new rejection limits.
+	    if (IS_INDEFR(losigma))
+		locut = max (-MAX_REAL, dmin)
+	    else if (i == 1)
+		locut = sky_med - min (sky_med - dmin, dmax - sky_med,
+		    losigma * sky_sigma)
+	    else
+	        locut = sky_med - losigma * sky_sigma
+	    if (IS_INDEFR(hisigma))
+		hicut = min (MAX_REAL, dmax)
+	    else if (i == 1)
+		hicut = sky_med + min (dmax - sky_med, sky_med - dmin,
+		    hisigma * sky_sigma)
+	    else
+	        hicut = sky_med + hisigma * sky_sigma
+	    #call printf ("    locut=%g hicut=%g\n")
+		#call pargr (locut)
+		#call pargr (hicut)
+
+	    # Detect pixels to be rejected.
+	    for (il = ilo; il <= nskypix; il = il + 1) {
+		if (skypix[index[il]] >= locut)
+		    break
+	    }
+	    for (ih = ihi; ih >= 1; ih = ih - 1) {
+		if (skypix[index[ih]] <= hicut)
+		    break
+	    }
+	    if (il == ilo && ih == ihi)
+		break
+
+	    # Reject pixels with optional region growing.
+	    if (rgrow > 0.0) {
+
+		# Reject low side pixels with region growing.
+	        do j = ilo, il - 1 
+		    nsky_reject = nsky_reject + ap_grow_regions (skypix, coords,
+		        wgt, nskypix, sky_zero, index[j], snx, sny, rgrow,
+			sumpx, sumsqpx, sumcbpx)
+
+		# Reject high side pixels with region growing.
+		do j = ih + 1, ihi
+		    nsky_reject = nsky_reject + ap_grow_regions (skypix, coords,
+		        wgt, nskypix, sky_zero, index[j], snx, sny, rgrow,
+			sumpx, sumsqpx, sumcbpx)
+
+		# Recompute the median.
+		# and the median pixel
+		nsky = nskypix - nsky_reject
+		med = apimed (wgt, index, il, ih, (nsky + 1) / 2)
+
+
+	    } else {
+
+		# Recompute the number of sky pixels, the number of rejected
+		# pixels and median pixel
+		nsky_reject = nsky_reject + (il - ilo) + (ihi - ih)
+		nsky = nskypix - nsky_reject
+		med = (ih + il) / 2
+
+		# Reject pixels on the low side.
+		do j = ilo, il - 1 {
+		    dsky = skypix[index[j]] - sky_zero
+		    sumpx = sumpx - dsky
+		    sumsqpx = sumsqpx - dsky ** 2
+		    sumcbpx = sumcbpx - dsky ** 3
+		}
+
+		# Reject pixels on the high side.
+		do j = ih + 1, ihi {
+		    dsky = skypix[index[j]] - sky_zero
+		    sumpx = sumpx - dsky
+		    sumsqpx = sumsqpx - dsky ** 2
+		    sumcbpx = sumcbpx - dsky ** 3
+		}
+	    }
+	    if (nsky <= 0)
+		break
+
+	    # Recompute the median, sigma and skew.
+	    medcut = nint (MEDCUT * real (nsky))
+	    sky_med = apwsmed (skypix, index, wgt, nskypix, med, medcut)
+	    sky_med = max (dmin, min (sky_med, dmax))
+	    call apmoments (sumpx, sumsqpx, sumcbpx, nsky, sky_zero,
+	        sky_mean, sky_sigma, sky_skew)
+	    sky_mean = max (dmin, min (sky_mean, dmax))
+	    #call printf (
+	    #"    mean=%g med=%g sigma=%g nsky=%d nrej=%d dmin=%g dmax=%g\n")
+	        #call pargr (sky_mean)
+	        #call pargr (sky_med)
+	        #call pargr (sky_sigma)
+	        #call pargi (nsky)
+	        #call pargi (nsky_reject)
+	        #call pargr (dmin)
+	        #call pargr (dmax)
+
+	    if (sky_sigma <= 0.0)
+		break
+	    ilo = il
+	    ihi = ih
+	}
+
+	# Return an appropriate error code.
+	if (nsky == 0 || nsky_reject == nskypix) {
+	    nsky = 0
+	    nsky_reject = nskypix
+	    sky_med = INDEFR
+	    sky_sigma = INDEFR
+	    sky_skew = INDEFR
+	    return (AP_NSKY_TOO_SMALL)
+	} else
+	    return (AP_OK)
+end
diff --git a/noao/digiphot/apphot/fitsky/apmode.x b/noao/digiphot/apphot/fitsky/apmode.x
new file mode 100644
index 00000000..fc32ba43
--- /dev/null
+++ b/noao/digiphot/apphot/fitsky/apmode.x
@@ -0,0 +1,185 @@
+include <mach.h>
+include "../lib/fitsky.h"
+
+define	MEDCUT		0.025
+
+# AP_MODE -- Procedure to calculate the mode of the sky pixel array.
+
+int procedure ap_mode (skypix, coords, wgt, index, nskypix, snx, sny, losigma,
+	hisigma, rgrow, maxiter, sky_mode, sky_sigma, sky_skew, nsky,
+	nsky_reject)
+
+real	skypix[ARB]		# unsorted array of skypixels
+int	coords[ARB]		# coordinate array for regions growing
+real	wgt[ARB]		# array of weights for rejection
+int	index[ARB]		# indices in sort order
+int	nskypix			# total number of sky pixels
+int	snx, sny		# dimensions of the sky subraster
+real	losigma, hisigma	# number of sky_sigma for rejection
+real	rgrow			# radius of region growing
+int	maxiter			# maximum number of cycles of rejection
+real	sky_mode		# computed sky value
+real	sky_sigma		# the computed sky sigma
+real	sky_skew		# skew of sky pixels
+int	nsky			# the number of sky pixels used
+int	nsky_reject		# the number of sky pixels rejected
+
+double	dsky, sumpx, sumsqpx, sumcbpx
+int	i, j, ilo, ihi, il, ih, med, medcut
+real	dmin, dmax, locut, hicut, sky_zero, sky_mean, sky_med
+int	ap_grow_regions(), apimed()
+real	apsmed(), apwsmed(), ap_asumr()
+
+begin
+	# Initialize.
+	nsky = nskypix
+	nsky_reject = 0
+	sky_mode = INDEFR
+	sky_sigma = INDEFR
+	sky_skew = INDEFR
+	if (nskypix <= 0)
+	    return (AP_NOSKYAREA)
+
+	# Compute the median, sigma, skew and sky mode.
+	sky_zero = ap_asumr (skypix, index, nskypix) / nskypix
+	call ap_ialimr (skypix, index, nskypix, dmin, dmax)
+	medcut = nint (MEDCUT * real (nskypix))
+	sky_med = apsmed (skypix, index, nskypix, medcut)
+	sky_med = max (dmin, min (sky_med, dmax))
+	call apfimoments (skypix, index, nskypix, sky_zero, sumpx, sumsqpx,
+	    sumcbpx, sky_mean, sky_sigma, sky_skew)
+	sky_mean = max (dmin, min (sky_mean, dmax))
+	if (sky_mean < sky_med)
+	    sky_mode = sky_mean
+	else
+	    sky_mode = 3.0 * sky_med - 2.0 * sky_mean
+	sky_mode = max (dmin, min (sky_mode, dmax))
+	if (maxiter < 1 || (IS_INDEFR(losigma) && IS_INDEFR(hisigma)) ||
+	    sky_sigma <= 0.0)
+	    return (AP_OK)
+
+	# Reject points outside losigma * sky_sigma and hisigma * sky_sigma
+	# of the mode.
+	ilo = 1
+	ihi = nskypix
+	do i = 1, maxiter {
+
+	    # Compute the new rejection limits.
+	    if (i == 1) {
+		if (IS_INDEFR(losigma))
+		    locut = max (-MAX_REAL, dmin)
+		else
+	            locut = sky_med - min (sky_med - dmin, dmax - sky_med,
+		        losigma * sky_sigma)
+		if (IS_INDEFR(hisigma))
+		    hicut = min (MAX_REAL, dmax)
+		else
+	            hicut = sky_med + min (sky_med - dmin, dmax - sky_med,
+		        hisigma * sky_sigma)
+	    } else {
+		if (IS_INDEFR(losigma))
+		    locut = max (-MAX_REAL, dmin)
+		else
+	            locut = sky_mode - losigma * sky_sigma
+		if (IS_INDEFR(hisigma))
+		    hicut = min (MAX_REAL, dmax)
+		else
+	            hicut = sky_mode + hisigma * sky_sigma
+	    }
+	    #call eprintf ("i=%d mean=%g median=%g mode=%g locut=%g hicut=%g\n")
+		#call pargi (i)
+		#call pargr (sky_mean)
+		#call pargr (sky_med)
+		#call pargr (sky_mode)
+		#call pargr (locut)
+		#call pargr (hicut)
+
+	    # Perform lower bound pixel rejection.
+	    for (il = ilo; il <= nskypix; il = il + 1) {
+		if (skypix[index[il]] >= locut)
+		    break
+	    }
+
+	    # Perform upper bound pixel rejection.
+	    for (ih = ihi; ih >= 1; ih = ih - 1) {
+		if (skypix[index[ih]] <= hicut)
+		    break
+	    }
+	    if (il == ilo && ih == ihi)
+		break
+
+	    # Compute number of rejected pixels with optional region growing.
+	    if (rgrow > 0.0) {
+
+		# Reject lower bound pixels with region growing.
+	        do j = ilo, il - 1 
+		    nsky_reject = nsky_reject + ap_grow_regions (skypix, coords,
+		        wgt, nskypix, sky_zero, index[j], snx, sny, rgrow,
+			sumpx, sumsqpx, sumcbpx)
+
+		# Reject upper bound pixels with region growing.
+		do j = ih + 1, ihi
+		    nsky_reject = nsky_reject + ap_grow_regions (skypix, coords,
+		        wgt, nskypix, sky_zero, index[j], snx, sny, rgrow,
+			sumpx, sumsqpx, sumcbpx)
+
+		# Compute the new median.
+		nsky = nskypix - nsky_reject
+		med = apimed (wgt, index, il, ihi, (nsky + 1) / 2)
+
+	    } else {
+
+		# Recompute the number of sky pixels, number of rejected
+		# pixels and the median.
+		nsky_reject = nsky_reject + (il - ilo) + (ihi - ih)
+	        nsky = nskypix - nsky_reject
+		med = (ih + il) / 2
+
+		# Reject number of lower bound pixels.
+		do j = ilo, il - 1 {
+		    dsky = skypix[index[j]] - sky_zero
+		    sumpx = sumpx - dsky
+		    sumsqpx = sumsqpx - dsky ** 2
+		    sumcbpx = sumcbpx - dsky ** 3
+		}
+
+		# Reject number of upper bound pixels.
+		do j = ih + 1, ihi {
+		    dsky = skypix[index[j]] - sky_zero
+		    sumpx = sumpx - dsky
+		    sumsqpx = sumsqpx - dsky ** 2
+		    sumcbpx = sumcbpx - dsky ** 3
+		}
+	    }
+	    if (nsky <= 0)
+		break
+
+	    # Recompute mean, median, mode, sigma and skew.
+	    medcut = nint (MEDCUT * real (nsky))
+	    sky_med = apwsmed (skypix, index, wgt, nskypix, med, medcut)
+	    sky_med = max (dmin, min (sky_med, dmax))
+	    call apmoments (sumpx, sumsqpx, sumcbpx, nsky, sky_zero,
+	        sky_mean, sky_sigma, sky_skew)
+	    sky_mean = max (dmin, min (sky_mean, dmax))
+	    if (sky_mean < sky_med)
+		sky_mode = sky_mean
+	    else
+	        sky_mode = 3.0 * sky_med - 2.0 * sky_mean
+	    sky_mode = max (dmin, min (sky_mode, dmax))
+	    if (sky_sigma <= 0.0)
+		break
+	    ilo = il
+	    ihi = ih
+	}
+
+	# Return an appropriate error code.
+	if (nsky == 0 || nsky_reject == nskypix) {
+	    nsky = 0
+	    nsky_reject = nskypix
+	    sky_mode = INDEFR
+	    sky_sigma = INDEFR
+	    sky_skew = INDEFR
+	    return (AP_NSKY_TOO_SMALL)
+	} else
+	    return (AP_OK)
+end
diff --git a/noao/digiphot/apphot/fitsky/appsky.x b/noao/digiphot/apphot/fitsky/appsky.x
new file mode 100644
index 00000000..8da9773e
--- /dev/null
+++ b/noao/digiphot/apphot/fitsky/appsky.x
@@ -0,0 +1,103 @@
+include "../lib/apphot.h"
+include "../lib/fitsky.h"
+
+# AP_PSSKY -- Procedure to write the results of the fitsky task to
+# the output file.
+
+procedure ap_pssky (ap, fd, id, ld, ier)
+
+pointer	ap		# pointer to apphot structure
+int	fd		# output file descriptor
+int	id		# sequence number of star
+int	ld		# list number of star
+int	ier		# error code
+
+real	apstatr()
+
+begin
+	# Return if NULL file descriptor.
+	if (fd == NULL)
+	    return
+
+	# Print the object id and computed sky values.
+	call ap_wid (ap, fd, apstatr (ap, OSXCUR), apstatr (ap, OSYCUR), id,
+	    ld, '\\')
+	call ap_wsres (ap, fd, ier, ' ')
+end
+
+
+# AP_QSPSKY -- Procedure to print a quick summary of the fitsky task on the
+# standard output.
+
+procedure ap_qspsky (ap, ier)
+
+pointer	ap		# pointer to apphot structure
+int	ier		# error code
+
+pointer	sp, imname
+int	apstati()
+real	apstatr()
+
+begin
+	# Print out the results on the standard output.
+	call smark (sp)
+	call salloc (imname, SZ_FNAME, TY_CHAR)
+	call apstats (ap, IMROOT, Memc[imname], SZ_FNAME)
+	call printf ( "%s  %8.2f %8.2f  %8g %8g ") 
+	    call pargstr (Memc[imname])
+	    call pargr (apstatr (ap, OSXCUR))
+	    call pargr (apstatr (ap, OSYCUR))
+	    call pargr (apstatr (ap, SKY_MODE))
+	    call pargr (apstatr (ap, SKY_SIGMA))
+	call printf ("%8g  %5d %5d  %s\n")
+	    call pargr (apstatr (ap, SKY_SKEW))
+	    call pargi (apstati (ap, NSKY))
+	    call pargi (apstati (ap, NSKY_REJECT))
+	    if (ier != AP_OK)
+		call pargstr ("err")
+	    else
+		call pargstr ("ok")
+	call sfree (sp)
+end
+
+
+# AP_QASPSKY -- Procedure to print a quick summary of the fitsky task on the
+# standard output.
+
+procedure ap_qaspsky (ap, ier)
+
+pointer	ap		# pointer to apphot structure
+int	ier		# error code
+
+int	apstati()
+real	apstatr()
+
+begin
+	# Print out the results on the standard output.
+	call printf ( "    Averages  %8g %8g ") 
+	    call pargr (apstatr (ap, SKY_MODE))
+	    call pargr (apstatr (ap, SKY_SIGMA))
+	call printf ("%8g  %5d %5d  %s\n\n")
+	    call pargr (apstatr (ap, SKY_SKEW))
+	    call pargi (apstati (ap, NSKY))
+	    call pargi (apstati (ap, NSKY_REJECT))
+	    if (ier != AP_OK)
+		call pargstr ("err")
+	    else
+		call pargstr ("ok")
+end
+
+# AP_SPHDR -- Procedure to write the banner for the fitsky task to the
+# output file.
+
+procedure ap_sphdr (ap, fd)
+
+pointer	ap		# pointer to apphot structure
+int	fd		# output file descriptor
+
+begin
+	if (fd == NULL)
+	    return
+	call ap_idhdr (ap, fd)
+	call ap_shdr (ap, fd)
+end
diff --git a/noao/digiphot/apphot/fitsky/appspars.x b/noao/digiphot/apphot/fitsky/appspars.x
new file mode 100644
index 00000000..50da0f84
--- /dev/null
+++ b/noao/digiphot/apphot/fitsky/appspars.x
@@ -0,0 +1,22 @@
+include "../lib/display.h"
+
+# AP_PSPARS -- Procedure to write out the current sky fitting parameters
+# to the parameter files.
+
+procedure ap_pspars (ap)
+
+pointer	ap		# pointer to apphot structure
+
+bool	itob()
+int	apstati()
+
+begin
+	# Write the data dependent parameters.
+	call ap_dapars (ap)
+
+	# Write the sky fitting parameters.
+	call ap_sapars (ap)
+
+	# Radial profile plots
+	call clputb ("radplots", itob (apstati (ap, RADPLOTS)))
+end
diff --git a/noao/digiphot/apphot/fitsky/apradplot.x b/noao/digiphot/apphot/fitsky/apradplot.x
new file mode 100644
index 00000000..d9d19992
--- /dev/null
+++ b/noao/digiphot/apphot/fitsky/apradplot.x
@@ -0,0 +1,91 @@
+include "../lib/fitsky.h"
+
+# AP_RADPLOT -- Procedure to compute the mode, sigma, and skew of the sky by
+# eye using a radial profile plot of the sky pixels and cursor readback.
+
+int procedure ap_radplot (gd, gt, skypix, coords, index, nskypix, sxc, syc,
+	snx, sny, scale, sky_mode, sky_skew, sky_sigma, nsky,
+	nsky_reject)
+
+pointer	gd			# pointer to graphics stream
+pointer	gt			# pointer to gtools structure
+real	skypix[ARB]		# array of sky pixels
+int	coords[ARB]		# array of sky coordinates
+int	index[ARB]		# the index array
+int	nskypix			# number of sky pixels
+real	sxc, syc		# sky subraster center
+int	snx, sny		# sky subraster size
+real	scale			# the image scale
+real	sky_mode		# computed sky value
+real	sky_sigma		# computed sigma of sky pixels
+real	sky_skew		# computed skew of sky pixels
+int	nsky			# number of sky pixels used in fit
+int	nsky_reject		# number of rejected sky pixels
+
+double	sumpx, sumsqpx, sumcbpx
+int	wcs, key
+pointer	sp, r, cmd
+real	wx, wy, xmin, xmax, ymin, ymax, u1, u2, v1, v2, x1, x2, y1, y2
+real	sky_zero
+int	clgcur()
+real	ap_asumr()
+
+begin
+	if (gd == NULL)
+	    return (AP_NOGRAPHICS)
+
+	# Initialize.
+	nsky = nskypix
+	nsky_reject = 0
+	sky_mode = INDEFR
+	sky_sigma = INDEFR
+	sky_skew = INDEFR
+	if (nskypix <= 0)
+	    return (AP_SKY_OUTOFBOUNDS)
+
+	call smark (sp)
+	call salloc (r, nskypix, TY_REAL)
+	call salloc (cmd, SZ_LINE, TY_CHAR)
+
+	# Compute an initial guess at the data characteristics.
+	nsky = nskypix
+	sky_zero = ap_asumr (skypix, index, nskypix) / nskypix
+	call apfimoments (skypix, index, nskypix, sky_zero, sumpx, sumsqpx,
+	    sumcbpx, sky_mode, sky_sigma, sky_skew)
+
+	# Store the old window and viewport coordinates.
+	call ggview (gd, u1, u2, v1, v2)
+	call ggwind (gd, x1, x2, y1, y2)
+
+	# Compute the radial profile
+	call ap_xytor (coords, index, Memr[r], nskypix, sxc, syc, snx)
+	call alimr (Memr[r], nskypix, xmin, xmax)
+	call alimr (skypix, nskypix, ymin, ymax)
+
+	# Plot the radial profile.
+	call gclear (gd)
+	call ap_rset (gd, gt, xmin, xmax, ymin, ymax, scale)
+	call ap_plotrad (gd, gt, Memr[r], skypix, nskypix, "plus")
+
+	# Mark the sky level with the cursor.
+	call printf ("Mark sky level (%g) [space=mark,q=quit,:.help=help]:")
+	    call pargr (sky_mode)
+	call gscur (gd, (xmin + xmax) / 2.0, sky_mode)
+	while (clgcur ("gcommands", wx, wy, wcs, key, Memc[cmd], SZ_LINE) !=
+	    EOF) {
+	    if (key == 'q')
+		break
+	    else
+		sky_mode = wy
+	    call printf ("Mark sky level (%g) [space=mark,q=quit,:.help=help]:")
+	        call pargr (sky_mode)
+	    call gscur (gd, (xmin + xmax) / 2.0, sky_mode)
+	}
+
+	# Store the old window and viewport coordinates.
+	call gsview (gd, u1, u2, v1, v2)
+	call gswind (gd, x1, x2, y1, y2)
+
+	call sfree (sp)
+	return (AP_OK)
+end
diff --git a/noao/digiphot/apphot/fitsky/apreadsky.x b/noao/digiphot/apphot/fitsky/apreadsky.x
new file mode 100644
index 00000000..3db9a183
--- /dev/null
+++ b/noao/digiphot/apphot/fitsky/apreadsky.x
@@ -0,0 +1,40 @@
+# AP_READSKY -- Procedure to read sky values, sigma and skew from a file
+# The x and y positions, sky mode, sigma, and skew values, number of sky
+# pixels and number of rejected sky pixels are assumed to be columns
+# 1 to 7 respectively.
+
+int procedure ap_readsky (fd, x, y, sky_mode, sky_sigma, sky_skew, nsky,
+    nsky_reject)
+
+int	fd		# sky file descriptor
+real	x, y		# center of sky annulus
+real	sky_mode	# sky valye
+real	sky_sigma	# sky sigma
+real	sky_skew	# skew of sky pixels
+int	nsky		# number of sky pixels
+int	nsky_reject	# number of rejected pixesl
+
+int	stat
+int	fscan(), nscan()
+
+begin
+	# Initialize.
+	sky_mode = INDEFR
+	sky_sigma = INDEFR
+	sky_skew = INDEFR
+	nsky = 0
+	nsky_reject = 0
+
+	# Read in and decode a sky file text line.
+	stat = fscan (fd)
+	if (stat == EOF)
+	    return (EOF)
+	call gargr (x)
+	call gargr (y)
+	call gargr (sky_mode)
+	call gargr (sky_sigma)
+	call gargr (sky_skew)
+	call gargi (nsky)
+	call gargi (nsky_reject)
+	return (nscan ())
+end
diff --git a/noao/digiphot/apphot/fitsky/aprefitsky.x b/noao/digiphot/apphot/fitsky/aprefitsky.x
new file mode 100644
index 00000000..bc4ed6c2
--- /dev/null
+++ b/noao/digiphot/apphot/fitsky/aprefitsky.x
@@ -0,0 +1,371 @@
+include "../lib/apphotdef.h"
+include "../lib/apphot.h"
+include "../lib/noisedef.h"
+include "../lib/fitskydef.h"
+include "../lib/fitsky.h"
+
+# APREFITSKY -- Procedure to fit the sky using the pixels currently stored in
+# the sky fitting buffers.
+
+int procedure aprefitsky (ap, im, gd)
+
+pointer	ap		# pointer to the apphot structure
+pointer	im		# the input image descriptor
+pointer	gd		# pointer to graphics stream
+
+int	ier, nclip, nsky, ilo, ihi
+pointer	sky, nse, gt
+int	ap_mode(), ap_centroid(), ap_histplot(), ap_median()
+int	ap_radplot(), ap_gauss(), ap_lgsky(), ap_crosscor()
+int	ap_mean(), ap_clip()
+pointer	ap_gtinit()
+
+begin
+	# Initialize.
+	sky = AP_PSKY(ap)
+	nse = AP_NOISE(ap)
+	AP_SKY_MODE(sky) = INDEFR
+	AP_SKY_SIG(sky) = INDEFR
+	AP_SKY_SKEW(sky) = INDEFR
+	AP_NSKY(sky) = 0
+	AP_NSKY_REJECT(sky) = 0
+	if (IS_INDEFR(AP_SXCUR(sky)) || IS_INDEFR(AP_SYCUR(sky))) {
+            AP_OSXCUR(sky) = AP_SXCUR(sky)
+            AP_OSYCUR(sky) = AP_SYCUR(sky)
+	} else {
+            switch (AP_WCSOUT(ap)) {
+            case WCS_WORLD, WCS_PHYSICAL:
+                call ap_ltoo (ap, AP_SXCUR(sky), AP_SYCUR(sky), AP_OSXCUR(sky),
+		    AP_OSYCUR(sky), 1)
+            case WCS_TV:
+                call ap_ltov (im, AP_SXCUR(sky), AP_SYCUR(sky), AP_OSXCUR(sky),
+		    AP_OSYCUR(sky), 1)
+            default:
+                AP_OSXCUR(sky) = AP_SXCUR(sky)
+                AP_OSYCUR(sky) = AP_SYCUR(sky)
+            }
+	}
+
+	if (IS_INDEFR(AP_SXCUR(sky)) || IS_INDEFR(AP_SYCUR(sky)))
+	    return (AP_NOSKYAREA)
+
+	switch (AP_SKYFUNCTION(sky)) {
+
+	case AP_MEAN:
+
+	    # Initialize the weights.
+	    call amovkr (1.0, Memr[AP_SWGT(sky)], AP_NSKYPIX(sky))
+
+	    # Clip the data.
+	    if (AP_SLOCLIP(sky) > 0.0 || AP_SHICLIP(sky) > 0.0) {
+		nclip = ap_clip (Memr[AP_SKYPIX(sky)], Memi[AP_INDEX(sky)],
+		    AP_NSKYPIX(sky), AP_SLOCLIP(sky), AP_SHICLIP(sky), ilo,
+		    ihi)
+		if (nclip >= AP_NSKYPIX(sky))
+		    return (AP_NSKY_TOO_SMALL)
+		nsky = AP_NSKYPIX(sky) - nclip
+	    } else {
+		nclip = 0
+		call ap_index (Memi[AP_INDEX(sky)], AP_NSKYPIX(sky))
+		ilo = 1
+		nsky = AP_NSKYPIX(sky) 
+	    }
+
+	    ier = ap_mean (Memr[AP_SKYPIX(sky)], Memi[AP_COORDS(sky)],
+	        Memr[AP_SWGT(sky)], Memi[AP_INDEX(sky)+ilo-1], nsky,
+		AP_SNX(sky), AP_SNY(sky), AP_SLOREJECT(sky),
+		AP_SHIREJECT(sky), AP_RGROW(sky) * AP_SCALE(ap),
+		AP_SNREJECT(sky), AP_SKY_MODE(sky), AP_SKY_SIG(sky),
+		AP_SKY_SKEW(sky), AP_NSKY(sky), AP_NSKY_REJECT(sky))
+	    AP_NSKY_REJECT(sky) = AP_NBADSKYPIX(sky) + nclip +
+	        AP_NSKY_REJECT(sky) 
+
+	    return (ier)
+
+	case AP_MEDIAN:
+
+	    # Initialize the weights.
+	    call amovkr (1.0, Memr[AP_SWGT(sky)], AP_NSKYPIX(sky))
+
+	    # Clip the data.
+	    if (AP_SLOCLIP(sky) > 0.0 || AP_SHICLIP(sky) > 0.0) {
+		nclip = ap_clip (Memr[AP_SKYPIX(sky)], Memi[AP_INDEX(sky)],
+		    AP_NSKYPIX(sky), AP_SLOCLIP(sky), AP_SHICLIP(sky), ilo,
+		    ihi)
+		if (nclip >= AP_NSKYPIX(sky))
+		    return (AP_NSKY_TOO_SMALL)
+		nsky = AP_NSKYPIX(sky) - nclip
+	    } else {
+		nclip = 0
+		call apqsort (Memr[AP_SKYPIX(sky)], Memi[AP_INDEX(sky)],
+		    Memi[AP_INDEX(sky)], AP_NSKYPIX(sky))
+		ilo = 1
+		nsky = AP_NSKYPIX(sky) 
+	    }
+
+	    ier = ap_median (Memr[AP_SKYPIX(sky)], Memi[AP_COORDS(sky)],
+	        Memr[AP_SWGT(sky)], Memi[AP_INDEX(sky)+ilo-1], nsky,
+		AP_SNX(sky), AP_SNY(sky), AP_SLOREJECT(sky),
+		AP_SHIREJECT(sky), AP_RGROW(sky) * AP_SCALE(ap),
+		AP_SNREJECT(sky), AP_SKY_MODE(sky), AP_SKY_SIG(sky),
+		AP_SKY_SKEW(sky), AP_NSKY(sky), AP_NSKY_REJECT(sky))
+	    AP_NSKY_REJECT(sky) = AP_NBADSKYPIX(sky) + nclip +
+	        AP_NSKY_REJECT(sky) 
+	    return (ier)
+
+	case AP_MODE:
+
+	    # Initialize the weights.
+	    call amovkr (1.0, Memr[AP_SWGT(sky)], AP_NSKYPIX(sky))
+
+	    # Clip the data.
+	    if (AP_SLOCLIP(sky) > 0.0 || AP_SHICLIP(sky) > 0.0) {
+		nclip = ap_clip (Memr[AP_SKYPIX(sky)], Memi[AP_INDEX(sky)],
+		    AP_NSKYPIX(sky), AP_SLOCLIP(sky), AP_SHICLIP(sky), ilo,
+		    ihi)
+		if (nclip >= AP_NSKYPIX(sky))
+		    return (AP_NSKY_TOO_SMALL)
+		nsky = AP_NSKYPIX(sky) - nclip
+	    } else {
+		nclip = 0
+		call apqsort (Memr[AP_SKYPIX(sky)], Memi[AP_INDEX(sky)],
+		    Memi[AP_INDEX(sky)], AP_NSKYPIX(sky))
+		ilo = 1
+		nsky = AP_NSKYPIX(sky) 
+	    }
+
+	    ier = ap_mode (Memr[AP_SKYPIX(sky)], Memi[AP_COORDS(sky)],
+	        Memr[AP_SWGT(sky)], Memi[AP_INDEX(sky)+ilo-1], nsky,
+		AP_SNX(sky), AP_SNY(sky), AP_SLOREJECT(sky),
+		AP_SHIREJECT(sky), AP_RGROW(sky) * AP_SCALE(ap),
+		AP_SNREJECT(sky), AP_SKY_MODE(sky), AP_SKY_SIG(sky),
+		AP_SKY_SKEW(sky), AP_NSKY(sky), AP_NSKY_REJECT(sky))
+	    AP_NSKY_REJECT(sky) = AP_NBADSKYPIX(sky) + nclip +
+	        AP_NSKY_REJECT(sky) 
+
+	    return (ier)
+
+	case AP_CENTROID:
+
+	    # Initialize the weights.
+	    call amovkr (1.0, Memr[AP_SWGT(sky)], AP_NSKYPIX(sky))
+
+	    # Clip the data.
+	    if (AP_SLOCLIP(sky) > 0.0 || AP_SHICLIP(sky) > 0.0) {
+		nclip = ap_clip (Memr[AP_SKYPIX(sky)], Memi[AP_INDEX(sky)],
+		    AP_NSKYPIX(sky), AP_SLOCLIP(sky), AP_SHICLIP(sky), ilo,
+		    ihi)
+		if (nclip >= AP_NSKYPIX(sky))
+		    return (AP_NSKY_TOO_SMALL)
+		nsky = AP_NSKYPIX(sky) - nclip
+	    } else {
+		nclip = 0
+		call ap_index (Memi[AP_INDEX(sky)], AP_NSKYPIX(sky))
+		ilo = 1
+		nsky = AP_NSKYPIX(sky) 
+	    }
+
+	    ier = ap_centroid (Memr[AP_SKYPIX(sky)], Memi[AP_COORDS(sky)],
+	        Memr[AP_SWGT(sky)+ilo-1], Memi[AP_INDEX(sky)+ilo-1], nsky,
+		AP_SNX(sky), AP_SNY(sky), AP_K1(sky), INDEFR,
+		AP_BINSIZE(sky), AP_SMOOTH(sky), AP_SLOREJECT(sky),
+		AP_SHIREJECT(sky), AP_RGROW(sky) * AP_SCALE(ap),
+		AP_SMAXITER(sky), AP_SKY_MODE(sky), AP_SKY_SIG(sky),
+		AP_SKY_SKEW(sky), AP_NSKY(sky), AP_NSKY_REJECT(sky))
+	    AP_NSKY_REJECT(sky) = AP_NBADSKYPIX(sky) + nclip +
+	        AP_NSKY_REJECT(sky) 
+
+	    return (ier)
+
+	case AP_CONSTANT:
+
+	    AP_SKY_MODE(sky) = AP_SKYBACKGROUND(sky)
+	    AP_SKY_SIG(sky) = AP_SKYSIGMA(nse)
+	    AP_SKY_SKEW(sky) = INDEFR
+	    AP_NSKY(sky) = 0
+	    AP_NSKY_REJECT(sky) = 0
+	    return (AP_OK)
+
+	case AP_SKYFILE:
+
+	    return (AP_OK)
+
+	case AP_RADPLOT:
+
+	    # Check the status of the graphics stream.
+	    if (gd == NULL)
+		return (AP_NOGRAPHICS)
+
+	    # Clip the data.
+	    if (AP_SLOCLIP(sky) > 0.0 || AP_SHICLIP(sky) > 0.0) {
+		nclip = ap_clip (Memr[AP_SKYPIX(sky)], Memi[AP_INDEX(sky)],
+		    AP_NSKYPIX(sky), AP_SLOCLIP(sky), AP_SHICLIP(sky), ilo,
+		    ihi)
+		if (nclip >= AP_NSKYPIX(sky))
+		    return (AP_NSKY_TOO_SMALL)
+		nsky = AP_NSKYPIX(sky) - nclip
+	    } else {
+		nclip = 0
+		call ap_index (Memi[AP_INDEX(sky)], AP_NSKYPIX(sky))
+		ilo = 1
+		nsky = AP_NSKYPIX(sky) 
+	    }
+
+	    call gactivate (gd, 0)
+	    gt = ap_gtinit (AP_IMROOT(ap), AP_SXCUR(sky), AP_SYCUR(sky))
+	    ier = ap_radplot (gd, gt, Memr[AP_SKYPIX(sky)],
+	        Memi[AP_COORDS(sky)], Memi[AP_INDEX(sky)+ilo-1], nsky,
+		AP_SXC(sky), AP_SYC(sky), AP_SNX(sky), AP_SNY(sky),
+		AP_SCALE(ap), AP_SKY_MODE(sky), AP_SKY_SIG(sky),
+		AP_SKY_SKEW(sky), AP_NSKY(sky), AP_NSKY_REJECT(sky))
+	    AP_NSKY_REJECT(sky) = AP_NBADSKYPIX(sky) + nclip +
+	        AP_NSKY_REJECT(sky) 
+	    call ap_gtfree (gt)
+	    call gdeactivate (gd, 0)
+
+	    return (ier)
+
+	case AP_HISTPLOT:
+
+	    # Check the status of the graphics stream.
+	    if (gd == NULL)
+		return (AP_NOGRAPHICS)
+
+	    # Initialize the weights.
+	    call amovkr (1.0, Memr[AP_SWGT(sky)], AP_NSKYPIX(sky))
+
+	    # Clip the data.
+	    if (AP_SLOCLIP(sky) > 0.0 || AP_SHICLIP(sky) > 0.0) {
+		nclip = ap_clip (Memr[AP_SKYPIX(sky)], Memi[AP_INDEX(sky)],
+		    AP_NSKYPIX(sky), AP_SLOCLIP(sky), AP_SHICLIP(sky), ilo,
+		    ihi)
+		if (nclip >= AP_NSKYPIX(sky))
+		    return (AP_NSKY_TOO_SMALL)
+		nsky = AP_NSKYPIX(sky) - nclip
+	    } else {
+		nclip = 0
+		call ap_index (Memi[AP_INDEX(sky)], AP_NSKYPIX(sky))
+		ilo = 1
+		nsky = AP_NSKYPIX(sky) 
+	    }
+
+	    #call gactivate (gd, 0)
+	    gt = ap_gtinit (AP_IMROOT(ap), AP_SXCUR(sky), AP_SYCUR(sky))
+	    ier = ap_histplot (gd, gt, Memr[AP_SKYPIX(sky)],
+	        Memr[AP_SWGT(sky)], Memi[AP_INDEX(sky)+ilo-1], nsky,
+		AP_K1(sky), INDEFR, AP_BINSIZE(sky), AP_SMOOTH(sky),
+		AP_SKY_MODE(sky), AP_SKY_SIG(sky), AP_SKY_SKEW(sky),
+		AP_NSKY(sky), AP_NSKY_REJECT(sky))	
+	    AP_NSKY_REJECT(sky) = AP_NBADSKYPIX(sky) + nclip +
+	        AP_NSKY_REJECT(sky) 
+	    call ap_gtfree (gt)
+
+	    return (ier)
+
+	case AP_OFILT:
+
+	    # Initialize the weights.
+	    call amovkr (1.0, Memr[AP_SWGT(sky)], AP_NSKYPIX(sky))
+
+	    # Clip the data.
+	    if (AP_SLOCLIP(sky) > 0.0 || AP_SHICLIP(sky) > 0.0) {
+		nclip = ap_clip (Memr[AP_SKYPIX(sky)], Memi[AP_INDEX(sky)],
+		    AP_NSKYPIX(sky), AP_SLOCLIP(sky), AP_SHICLIP(sky), ilo,
+		    ihi)
+		if (nclip >= AP_NSKYPIX(sky))
+		    return (AP_NSKY_TOO_SMALL)
+		nsky = AP_NSKYPIX(sky) - nclip
+	    } else {
+		nclip = 0
+		call ap_index (Memi[AP_INDEX(sky)], AP_NSKYPIX(sky))
+		ilo = 1
+		nsky = AP_NSKYPIX(sky) 
+	    }
+
+	    ier = ap_lgsky (Memr[AP_SKYPIX(sky)], Memi[AP_COORDS(sky)],
+	        Memr[AP_SWGT(sky)], Memi[AP_INDEX(sky)+ilo-1], nsky,
+		AP_SNX(sky), AP_SNY(sky), AP_K1(sky), INDEFR,
+		AP_BINSIZE(sky), AP_SMOOTH(sky), AP_SLOREJECT(sky),
+		AP_SHIREJECT(sky), AP_RGROW(sky) * AP_SCALE(ap),
+		AP_SMAXITER(sky), AP_SKY_MODE(sky), AP_SKY_SIG(sky),
+		AP_SKY_SKEW(sky), AP_NSKY(sky), AP_NSKY_REJECT(sky))
+	    AP_NSKY_REJECT(sky) = AP_NBADSKYPIX(sky) + nclip +
+	        AP_NSKY_REJECT(sky) 
+
+	    return (ier)
+
+	case AP_GAUSS:
+
+	    # Initialize the weights.
+	    call amovkr (1.0, Memr[AP_SWGT(sky)], AP_NSKYPIX(sky))
+
+	    # Clip the data.
+	    if (AP_SLOCLIP(sky) > 0.0 || AP_SHICLIP(sky) > 0.0) {
+		nclip = ap_clip (Memr[AP_SKYPIX(sky)], Memi[AP_INDEX(sky)],
+		    AP_NSKYPIX(sky), AP_SLOCLIP(sky), AP_SHICLIP(sky), ilo,
+		    ihi)
+		if (nclip >= AP_NSKYPIX(sky))
+		    return (AP_NSKY_TOO_SMALL)
+		nsky = AP_NSKYPIX(sky) - nclip
+	    } else {
+		nclip = 0
+		call ap_index (Memi[AP_INDEX(sky)], AP_NSKYPIX(sky))
+		ilo = 1
+		nsky = AP_NSKYPIX(sky) 
+	    }
+
+	    ier = ap_gauss (Memr[AP_SKYPIX(sky)], Memi[AP_COORDS(sky)],
+	        Memr[AP_SWGT(sky)], Memi[AP_INDEX(sky)+ilo-1], nsky,
+		AP_SNX(sky), AP_SNY(sky), AP_SMAXITER(sky),
+		AP_K1(sky), INDEFR, AP_BINSIZE(sky), AP_SMOOTH(sky),
+		AP_SLOREJECT(sky), AP_SHIREJECT(sky), AP_RGROW(sky) *
+		AP_SCALE(ap), AP_SNREJECT(sky), AP_SKY_MODE(sky),
+		AP_SKY_SIG(sky), AP_SKY_SKEW(sky), AP_NSKY(sky),
+		AP_NSKY_REJECT(sky))
+	    AP_NSKY_REJECT(sky) = AP_NBADSKYPIX(sky) + nclip +
+	        AP_NSKY_REJECT(sky) 
+
+	    return (ier)
+
+	case AP_CROSSCOR:
+
+	    # Initialize the weights.
+	    call amovkr (1.0, Memr[AP_SWGT(sky)], AP_NSKYPIX(sky))
+
+	    # Clip the data.
+	    if (AP_SLOCLIP(sky) > 0.0 || AP_SHICLIP(sky) > 0.0) {
+		nclip = ap_clip (Memr[AP_SKYPIX(sky)], Memi[AP_INDEX(sky)],
+		    AP_NSKYPIX(sky), AP_SLOCLIP(sky), AP_SHICLIP(sky), ilo,
+		    ihi)
+		if (nclip >= AP_NSKYPIX(sky))
+		    return (AP_NSKY_TOO_SMALL)
+		nsky = AP_NSKYPIX(sky) - nclip
+	    } else {
+		nclip = 0
+		call ap_index (Memi[AP_INDEX(sky)], AP_NSKYPIX(sky))
+		ilo = 1
+		nsky = AP_NSKYPIX(sky) 
+	    }
+
+	    ier = ap_crosscor (Memr[AP_SKYPIX(sky)], Memi[AP_COORDS(sky)],
+	        Memr[AP_SWGT(sky)], Memi[AP_INDEX(sky)+ilo-1], nsky,
+		AP_SNX(sky), AP_SNY(sky), AP_K1(sky), INDEFR,
+		AP_BINSIZE(sky), AP_SMOOTH(sky), AP_SLOREJECT(sky),
+		AP_SHIREJECT(sky), AP_RGROW(sky) * AP_SCALE(ap),
+		AP_SMAXITER(sky), AP_SKY_MODE(sky), AP_SKY_SIG(sky),
+		AP_SKY_SKEW(sky), AP_NSKY(sky), AP_NSKY_REJECT(sky))
+	    AP_NSKY_REJECT(sky) = AP_NBADSKYPIX(sky) + nclip +
+	        AP_NSKY_REJECT(sky) 
+
+	    return (ier)
+
+	default:
+
+	    AP_SKY_MODE(sky) = INDEFR
+	    AP_SKY_SIG(sky) = INDEFR
+	    AP_SKY_SKEW(sky) = INDEFR
+	    AP_NSKY(sky) = AP_NSKYPIX(sky)
+	    AP_NSKY_REJECT(sky) = 0
+	    return (AP_OK)
+	}
+end
diff --git a/noao/digiphot/apphot/fitsky/aprgrow.x b/noao/digiphot/apphot/fitsky/aprgrow.x
new file mode 100644
index 00000000..902b91d6
--- /dev/null
+++ b/noao/digiphot/apphot/fitsky/aprgrow.x
@@ -0,0 +1,64 @@
+# AP_GROW_REGIONS -- Perform region growing around a rejected pixel.
+
+int procedure ap_grow_regions (skypix, coords, wgt, nskypix, sky_zero,
+	index, snx, sny, rgrow, sumpx, sumsqpx, sumcbpx)
+
+real	skypix[ARB]		# sky pixels
+int	coords[ARB]		# sky cordinates
+real	wgt[ARB]		# weights
+int	nskypix			# total number of sky pixels
+real	sky_zero		# sky zero point for moment analysis
+int	index			# index of pixel to be rejected
+int	snx, sny		# size of sky subraster
+real	rgrow			# region growing radius
+double	sumpx, sumsqpx, sumcbpx	# sum and sum of squares of sky pixels
+
+double	dsky
+int	j, k, ixc, iyc, xmin, xmax, ymin, ymax, cstart, c, nreject
+real	rgrow2, r2, d
+
+begin
+	# Find the center of the region to be rejected.
+	ixc = mod (coords[index], snx)
+	if (ixc == 0)
+	    ixc = snx
+	iyc = (coords[index] - ixc) / snx + 1
+
+	# Define the region to be searched.
+	rgrow2 = rgrow ** 2
+	ymin = max (1, int (iyc - rgrow)) 
+	ymax = min (sny, int (iyc + rgrow))
+	xmin = max (1, int (ixc - rgrow))
+	xmax = min (snx, int (ixc + rgrow)) 
+	if (ymin <= iyc)
+	    cstart = min (nskypix, max (1, index - int (rgrow) + snx *
+	    (ymin - iyc)))
+	else
+	    cstart = index
+
+	# Reject the pixels.
+	nreject = 0
+	do j = ymin, ymax {
+	    d = rgrow2 - (j - iyc) ** 2
+	    if (d <= 0.0)
+		d = 0.0
+	    else
+		d = sqrt (d)
+	    do k = max (xmin, int (ixc - d)), min (xmax, int (ixc + d)) {
+		c = k + (j - 1) * snx
+	        while (coords[cstart] < c && cstart < nskypix)
+	    	    cstart = cstart + 1
+		r2 = (k - ixc) ** 2 + (j - iyc) ** 2
+		if (r2 <= rgrow2 && c == coords[cstart] && wgt[cstart] > 0.0) {
+		    dsky = skypix[cstart] - sky_zero
+		    sumpx = sumpx - dsky
+		    sumsqpx = sumsqpx - dsky ** 2
+		    sumcbpx = sumcbpx - dsky ** 3
+		    nreject = nreject + 1
+		    wgt[cstart] = 0.0
+		}
+	    }
+	}
+
+	return (nreject)
+end
diff --git a/noao/digiphot/apphot/fitsky/apsconfirm.x b/noao/digiphot/apphot/fitsky/apsconfirm.x
new file mode 100644
index 00000000..43c0b168
--- /dev/null
+++ b/noao/digiphot/apphot/fitsky/apsconfirm.x
@@ -0,0 +1,74 @@
+include "../lib/apphot.h"
+include "../lib/noise.h"
+include "../lib/fitsky.h"
+
+# AP_SCONFIRM -- Procedure to confirm the critical fitsky parameters.
+
+procedure ap_sconfirm (ap, out, stid)
+
+pointer	ap		# pointer to the apphot structure
+int	out		# output file descriptor
+int	stid		# output file sequence number
+
+pointer	sp, str
+real	annulus, dannulus, skysigma, datamin, datamax
+int	apstati()
+real	apstatr(), ap_vannulus(), ap_vdannulus(), ap_vsigma()
+real	ap_vdatamin(), ap_vdatamax()
+
+begin
+	call smark (sp)
+	call salloc (str, SZ_LINE, TY_CHAR)
+
+	call printf ("\n")
+
+	# Confirm the sky fitting algorithm.
+	call ap_vsstring (ap, Memc[str], SZ_FNAME)
+
+	# Confirm the remaining parameters.
+	if (apstati (ap, SKYFUNCTION) != AP_CONSTANT &&
+	    apstati (ap, SKYFUNCTION) != AP_SKYFILE) {
+
+	    # Confirm the sky annulus parameter.
+	    annulus = ap_vannulus (ap)
+
+	    # Confirm the width of the sky annulus.
+	    dannulus = ap_vdannulus (ap)
+
+	} else {
+
+	    annulus = apstatr (ap, ANNULUS)
+	    dannulus = apstatr (ap, DANNULUS)
+
+	}
+
+	# Confirm the sky sigma parameter.
+	if (apstati (ap, SKYFUNCTION) != AP_SKYFILE)
+	    skysigma = ap_vsigma (ap)
+	else
+	    skysigma = apstatr (ap, SKYSIGMA)
+
+	# Confirm the minimum and maximum good data values.
+	datamin = ap_vdatamin (ap)
+	datamax = ap_vdatamax (ap)
+
+	call printf ("\n")
+
+	# Update the database file.
+	if (out != NULL && stid > 1) {
+	    call ap_sparam (out, KY_SSTRING, Memc[str], UN_SALGORITHM,
+		"sky fitting algorithm")
+	    call ap_rparam (out, KY_ANNULUS, annulus, UN_SSCALEUNIT,
+	        "inner radius of sky annulus")
+	    call ap_rparam (out, KY_DANNULUS, dannulus, UN_SSCALEUNIT,
+	        "width of the sky annulus")
+	    call ap_rparam (out, KY_SKYSIGMA, skysigma, UN_NCOUNTS,
+	        "standard deviation of 1 sky pixel") 
+	    call ap_rparam (out, KY_DATAMIN, datamin, UN_ACOUNTS,
+	        "minimum good data value") 
+	    call ap_rparam (out, KY_DATAMAX, datamax, UN_ACOUNTS,
+	        "maximum good data value") 
+	}
+
+	call sfree (sp)
+end
diff --git a/noao/digiphot/apphot/fitsky/apserrors.x b/noao/digiphot/apphot/fitsky/apserrors.x
new file mode 100644
index 00000000..80c8f0a7
--- /dev/null
+++ b/noao/digiphot/apphot/fitsky/apserrors.x
@@ -0,0 +1,42 @@
+include "../lib/fitsky.h"
+
+# AP_SERRORS -- Program to print out detailed fitsky error messages when the
+# program is run in interactive mode.
+
+procedure ap_serrors (ap, ier)
+
+pointer	ap		# pointer to apphot structure (not used)
+int	ier		# integer error code
+
+begin
+	switch (ier) {
+	case AP_NOSKYAREA:
+	    call printf ("The are no pixels in the sky annulus.\n")
+	case AP_SKY_OUTOFBOUNDS:
+	    call printf ("The sky annulus is outside of the image.\n")
+	case AP_NOHISTOGRAM:
+	    call printf ("The sky histogram has no width.\n")
+	case AP_FLAT_HIST:
+	    call printf ("The sky histogram is flat or concave.\n")
+	case AP_NSKY_TOO_SMALL:
+	    call printf ("The number of sky points is too small.\n")
+	case AP_SKY_SINGULAR:
+	    call printf ("The sky fit is singular.\n")
+	case AP_SKY_NOCONVERGE:
+	    call printf ("The sky fit did not converge.\n")
+	case AP_NOGRAPHICS:
+	    call printf ("Interactive graphics are not available.\n")
+	case AP_NOSKYFILE:
+	    call printf (
+	        "The text file containing sky values does not exist.\n")
+	case AP_EOFSKYFILE:
+	    call printf ("The sky file is at EOF.\n")
+	case AP_BADSKYSCAN:
+	    call printf (
+	    "An error occurred in decoding the current line in the sky file.\n")
+	case AP_BADPARAMS:
+	    call printf ("Out of range mode or -ve sigma in Gaussian fit.\n")
+	default:
+	    call printf ("")
+	}
+end
diff --git a/noao/digiphot/apphot/fitsky/apsfree.x b/noao/digiphot/apphot/fitsky/apsfree.x
new file mode 100644
index 00000000..63d41090
--- /dev/null
+++ b/noao/digiphot/apphot/fitsky/apsfree.x
@@ -0,0 +1,48 @@
+include "../lib/apphotdef.h"
+include "../lib/fitskydef.h"
+
+# APSFREE -- Procedure to free the sky fitting structure.
+
+procedure apsfree (ap)
+
+pointer	ap		# pointer to the apphot structure
+
+begin
+	if (ap == NULL)
+	    return
+	if (AP_NOISE(ap) != NULL)
+	    call ap_noisecls (ap)
+	if (AP_PDISPLAY(ap) != NULL)
+	    call ap_dispcls (ap)
+	if (AP_PSKY(ap) != NULL)
+	    call ap_skycls (ap)
+	if (AP_IMBUF(ap) != NULL)
+	    call mfree (AP_IMBUF(ap), TY_REAL)
+	if (AP_MW(ap) != NULL)
+	    call mw_close (AP_MW(ap))
+	call mfree (ap, TY_STRUCT)
+end
+
+
+# AP_SKYCLS -- Procedure to close up the sky fitting arrays.
+
+procedure ap_skycls (ap)
+
+pointer	ap		# pointer to the apphot structure
+
+pointer	sky
+
+begin
+	sky = AP_PSKY(ap)
+	if (sky == NULL)
+	    return
+	if (AP_SKYPIX(sky) != NULL)
+	    call mfree (AP_SKYPIX(sky), TY_REAL)
+	if (AP_INDEX(sky) != NULL)
+	    call mfree (AP_INDEX(sky), TY_INT)
+	if (AP_COORDS(sky) != NULL)
+	    call mfree (AP_COORDS(sky), TY_INT)
+	if (AP_SWGT(sky) != NULL)
+	    call mfree (AP_SWGT(sky), TY_REAL)
+	call mfree (AP_PSKY(ap), TY_STRUCT)
+end
diff --git a/noao/digiphot/apphot/fitsky/apsinit.x b/noao/digiphot/apphot/fitsky/apsinit.x
new file mode 100644
index 00000000..e180835f
--- /dev/null
+++ b/noao/digiphot/apphot/fitsky/apsinit.x
@@ -0,0 +1,116 @@
+include "../lib/apphotdef.h"
+include "../lib/fitskydef.h"
+include "../lib/fitsky.h"
+
+# APSINIT - Procedure to initialize the sky fitting structure and parameters.
+
+procedure apsinit (ap, function, annulus, dannulus, fwhmpsf, noise)
+
+pointer	ap		# pointer to the apphot structure
+int	function	# sky fitting algorithm
+real	annulus		# radius of sky annulus
+real	dannulus	# width of sky annulus
+real	fwhmpsf		# FWHM of the PSF
+int	noise		# noise function
+
+begin
+	# Set up the object parameters.
+	call malloc (ap, LEN_APSTRUCT, TY_STRUCT)
+
+	# Set up the global apphot package parameters.
+	call ap_defsetup (ap, fwhmpsf)
+
+	# Set up the noise model parameters.
+	call ap_noisesetup (ap, noise)
+
+	# Set up the display options.
+	call ap_dispsetup (ap)
+
+	# Initialize the sky fitting parameters.
+	call ap_skysetup (ap, function, annulus, dannulus)
+
+	# Unused structures are set to null.
+	AP_PCENTER(ap) = NULL
+	AP_PPHOT(ap) = NULL
+	AP_POLY(ap) = NULL
+	AP_PPSF(ap) = NULL
+	AP_RPROF(ap) = NULL
+end
+
+
+# AP_SKYSETUP -- Procedure to set up the sky fitting arrays and parameters.
+
+procedure ap_skysetup (ap, function, annulus, dannulus)
+
+pointer	ap		# pointer to apphot structure
+int	function	# sky fitting function
+real	annulus		# inner radius of sky annulus
+real	dannulus	# outer radius of sky annulus
+
+pointer	sky
+
+begin
+	call malloc (AP_PSKY(ap), LEN_SKYSTRUCT, TY_STRUCT)
+	sky = AP_PSKY(ap)
+	AP_SXCUR(sky) = INDEFR
+	AP_SYCUR(sky) = INDEFR
+
+	# Initialize the sky fitting parameters.
+	AP_SKYFUNCTION(sky) = function
+	switch (function) {
+	case AP_CONSTANT:
+	    call strcpy ("constant", AP_SSTRING(sky), SZ_FNAME)
+	case AP_MODE:
+	    call strcpy ("mode", AP_SSTRING(sky), SZ_FNAME)
+	case AP_CENTROID:
+	    call strcpy ("centroid", AP_SSTRING(sky), SZ_FNAME)
+	case AP_SKYFILE:
+	    call strcpy ("file", AP_SSTRING(sky), SZ_FNAME)
+	case AP_HISTPLOT:
+	    call strcpy ("histplot", AP_SSTRING(sky), SZ_FNAME)
+	case AP_RADPLOT:
+	    call strcpy ("radplot", AP_SSTRING(sky), SZ_FNAME)
+	case AP_MEDIAN:
+	    call strcpy ("median", AP_SSTRING(sky), SZ_FNAME)
+	case AP_GAUSS:
+	    call strcpy ("gauss", AP_SSTRING(sky), SZ_FNAME)
+	case AP_OFILT:
+	    call strcpy ("ofilt", AP_SSTRING(sky), SZ_FNAME)
+	case AP_CROSSCOR:
+	    call strcpy ("crosscor", AP_SSTRING(sky), SZ_FNAME)
+	case AP_MEAN:
+	    call strcpy ("mean", AP_SSTRING(sky), SZ_FNAME)
+	default:
+	    AP_SKYFUNCTION(sky) = DEF_SKYFUNCTION
+	    call strcpy ("mode", AP_SSTRING(sky), SZ_FNAME)
+	}
+
+	AP_SKYBACKGROUND(sky) = DEF_SKYVALUE
+	AP_ANNULUS(sky) = annulus
+	AP_DANNULUS(sky) = dannulus
+	AP_K1(sky) = DEF_K1
+	AP_BINSIZE(sky) = DEF_BINSIZE
+	AP_SMOOTH(sky) = DEF_SMOOTH
+	AP_SLOCLIP(sky) = DEF_SLOCLIP
+	AP_SHICLIP(sky) = DEF_SHICLIP
+	AP_SMAXITER(sky) = DEF_SMAXITER
+	AP_RGROW(sky) = DEF_RGROW
+	AP_SNREJECT(sky) = DEF_SNREJECT
+	AP_SLOREJECT(sky) = DEF_SLOREJECT
+	AP_SHIREJECT(sky) = DEF_SHIREJECT
+
+	# Initialize the sky pixel buffers.
+	AP_LENSKYBUF(sky) = 0
+	AP_NSKYPIX(sky) = 0
+	AP_SKYPIX(sky) = NULL
+	AP_INDEX(sky) = NULL
+	AP_COORDS(sky) = NULL
+	AP_SWGT(sky) = NULL
+
+	# Initialize results parameters.
+	AP_SKY_MODE(sky) = INDEFR
+	AP_SKY_SIG(sky) = INDEFR
+	AP_SKY_SKEW(sky) = INDEFR
+	AP_NSKY(sky) = 0
+	AP_NSKY_REJECT(sky) = 0
+end
diff --git a/noao/digiphot/apphot/fitsky/apsky.x b/noao/digiphot/apphot/fitsky/apsky.x
new file mode 100644
index 00000000..40faac3d
--- /dev/null
+++ b/noao/digiphot/apphot/fitsky/apsky.x
@@ -0,0 +1,346 @@
+include <ctype.h>
+include <gset.h>
+include <imhdr.h>
+include "../lib/apphot.h"
+include "../lib/display.h"
+include "../lib/fitsky.h"
+
+define	HELPFILE	"apphot$fitsky/fitsky.key"
+
+# APSKY -- Procedure to interactively determine sky values in an annular
+# region around a list of objects.
+
+int procedure apsky (ap, im, cl, sd, gd, mgd, id, out, stid, interactive, cache)
+
+pointer ap			# pointer to apphot structure
+pointer	im			# pointer to IRAF image
+int	cl			# starlist file descriptor
+int	sd			# the sky file descriptor
+pointer	gd			# pointer to graphcis descriptor
+pointer	mgd			# pointer to graphics metacode file
+pointer	id			# pointer to image display stream
+int	out			# output file descriptor
+int	stid			# output file sequence number
+int	interactive		# interactive mode
+int	cache			# cache the input image pixels
+
+real	wx, wy, xlist, ylist
+pointer sp, cmd
+int	wcs, key, colonkey, newimage, newobject, newsky, newlist, ier
+int	ip, ltid, oid, prev_num, req_num, buf_size, req_size, old_size
+int	memstat
+
+real	apstatr()
+int	clgcur(), apfitsky(), aprefitsky(), apgscur(), ctoi(), apstati()
+int	apgqverify(), apgtverify(), apnew(), ap_memstat(), sizeof()
+
+define  endswitch_ 99
+
+begin
+	call smark (sp)
+	call salloc (cmd, SZ_LINE, TY_CHAR)
+
+	# Initialize cursor command.
+	key = ' '
+	Memc[cmd] = EOS
+
+	# Initialize fitting parameters.
+	newimage = NO
+	newobject = YES
+	newsky = YES
+	ier = AP_OK
+
+	# Initialize sequencing.
+	newlist = NO
+	ltid = 0
+
+	# Loop over the cursor commands.
+	while (clgcur ("icommands", wx, wy, wcs, key, Memc[cmd], SZ_LINE) !=
+	    EOF) {
+
+	    # Store the current cursor coordinates.
+	    call ap_vtol (im, wx, wy, wx, wy, 1)
+	    call apsetr (ap, CWX, wx)
+	    call apsetr (ap, CWY, wy)
+
+	    # Test to see if the cursor has moved.
+	    if (apnew (ap, wx, wy, xlist, ylist, newlist) == YES) {
+		newobject = YES
+		newsky = YES
+	    }
+
+	    # Loop over the colon commands.
+	    switch (key) {
+
+	    # Quit.
+	    case 'q':
+		if (interactive == YES) {
+		    if (apgqverify ("fitsky", ap, key) == YES) {
+			call sfree (sp)
+			return (apgtverify (key))
+		    }
+		} else {
+		    call sfree (sp)
+		    return (NO)
+		}
+
+	    # Print the error messages.
+	    case 'e':
+		if (interactive == YES)
+		    call ap_serrors (ap, ier)
+
+	    # Print the help page.
+	    case '?':
+		if ((id != NULL) && (id == gd))
+		    call gpagefile (id, HELPFILE, "")
+		else if (interactive == YES)
+		    call pagefile (HELPFILE, "[space=morehelp,q=quit,?=help]")
+
+	    # Rewind the coordinate file.
+	    case 'r':
+		if (cl != NULL) {
+		    call seek (cl, BOFL)
+		    ltid = 0
+		} else if (interactive == YES)
+		    call printf ("No coordinate list\n")
+
+	    # Verify the critical parameters.
+	    case 'v':
+		call ap_sconfirm (ap, out, stid)
+		newobject = YES
+		newsky = YES
+
+	    # Save the sky fitting parameters.
+	    case 'w':
+		call ap_pspars (ap)
+
+	    # Draw a centered radial profile plot.
+	    case 'd':
+	        if (interactive == YES) {
+		    call ap_qrad (ap, im, wx, wy, gd)
+		    newobject = YES
+		    newsky = YES
+	        }
+
+	    # Interactively set up sky fitting parameters.
+	    case 'i':
+		if (interactive == YES) {
+		    call ap_sradsetup (ap, im, wx, wy, gd, out, stid)
+		    newobject = YES
+		    newsky = YES
+		}
+
+	    # Process fitsky colon commands.
+	    case ':':
+		for (ip = 1; IS_WHITE(Memc[cmd+ip-1]); ip = ip + 1)
+		    ;
+		colonkey = Memc[cmd+ip-1]
+		switch (colonkey) {
+		case 'm', 'n':
+
+		    # Show/set fitsky commands.
+		    if (Memc[cmd+ip] != EOS && Memc[cmd+ip] != ' ') {
+		        call apskycolon (ap, im, cl, out, stid, ltid,
+			    Memc[cmd], newimage, newobject, newsky)
+			goto endswitch_
+		    }
+
+                    # No coordinate list.
+                    if (cl == NULL) {
+                        if (interactive == YES)
+                            call printf ("No coordinate list\n")
+                        goto endswitch_
+                    }
+
+		    # Get next object from the list.
+		    ip = ip + 1
+		    prev_num = ltid
+		    if (ctoi (Memc[cmd], ip, req_num) <= 0)
+			req_num = ltid + 1
+
+		    # Fetch the next object from the list.
+		    if (apgscur (cl, id, xlist, ylist, prev_num, req_num,
+		        ltid) == EOF) {
+                        if (interactive == YES)
+                            call printf (
+                            "End of coordinate list, use r key to rewind\n")
+                        goto endswitch_
+		    }
+
+                    # Convert the coordinates.
+                    switch (apstati (ap, WCSIN)) {
+                    case WCS_PHYSICAL, WCS_WORLD:
+                        call ap_itol (ap,  xlist, ylist, xlist, ylist, 1)
+                    case WCS_TV:
+                        call ap_vtol (im, xlist, ylist, xlist, ylist, 1)
+                    default:
+                        ;
+                    }
+
+		    # Move to the next object.
+		    newlist = YES
+		    if (colonkey == 'm') {
+		        newobject = YES
+			newsky = YES
+                        goto endswitch_
+		    }
+
+		    # Measure the next object.	
+		    ier = apfitsky (ap, im, xlist, ylist, sd, gd)
+		    if (id != NULL) {
+		        call apmark (ap, id, NO, apstati (ap, MKSKY), NO)
+			if (id == gd)
+			    call gflush (id)
+			else
+			    call gframe (id)
+		    }
+		    call ap_splot (ap, stid, gd, apstati (ap, RADPLOTS))
+		    if (interactive == YES)
+		        call ap_qspsky (ap, ier)
+		    if (stid == 1)
+		        call ap_param (ap, out, "fitsky")
+		    call ap_splot (ap, stid, mgd, YES)
+		    call ap_pssky (ap, out, stid, ltid, ier)
+		    stid = stid + 1
+		    newobject = NO; newsky = NO
+
+		default:
+		    call apskycolon (ap, im, cl, out, stid, ltid, Memc[cmd],
+		        newimage, newobject, newsky)
+		}
+
+		if (newimage == YES) {
+		    if ((id != NULL) && (gd != id))
+		        call ap_gswv (id, Memc[cmd], im, 4)
+                    req_size = MEMFUDGE * IM_LEN(im,1) * IM_LEN(im,2) *
+                        sizeof (IM_PIXTYPE(im))
+                    memstat = ap_memstat (cache, req_size, old_size)
+                    if (memstat == YES)
+                        call ap_pcache (im, INDEFI, buf_size)
+		}
+
+		newimage = NO
+
+	    # Fit the sky and store the results.
+	    case 'f', ' ':
+		if (newobject == YES)
+		    ier = apfitsky (ap, im, wx, wy, sd, gd)
+		else if (newsky == YES)
+		    ier = aprefitsky (ap, im, gd)
+		if (id != NULL) {
+		    call apmark (ap, id, NO, apstati (ap, MKSKY), NO)
+		    if (id == gd)
+			call gflush (id)
+		    else
+		        call gframe (id)
+		}
+		call ap_splot (ap, stid, gd, apstati (ap, RADPLOTS))
+		if (interactive == YES)
+		    call ap_qspsky (ap, ier)
+		newobject = NO; newsky = NO
+
+		if (key == ' ') {
+		    if (stid == 1)
+		        call ap_param (ap, out, "fitsky")
+		    if (newlist == YES)
+		        call ap_pssky (ap, out, stid, ltid, ier)
+		    else
+		        call ap_pssky (ap, out, stid, 0, ier)
+		    call ap_splot (ap, stid, mgd, YES)
+		    stid = stid + 1
+		}
+
+	    # Get, fit the next object in the list.
+	    case 'm', 'n':
+
+                # No coordinate file.
+                if (cl == NULL) {
+                    if (interactive == YES)
+                        call printf ("No coordinate list\n")
+                    goto endswitch_
+                }
+
+		# Need to rewind coordinate file.
+		prev_num = ltid
+		req_num = ltid + 1
+		if (apgscur (cl, id, xlist, ylist, prev_num, req_num,
+		    ltid) == EOF) {
+                    if (interactive == YES)
+                        call printf (
+                            "End of coordinate list, use r key to rewind\n")
+                    goto endswitch_
+
+		}
+
+                # Convert coordinates if necessary.
+                switch (apstati (ap, WCSIN)) {
+                case WCS_PHYSICAL, WCS_WORLD:
+                    call ap_itol (ap,  xlist, ylist, xlist, ylist, 1)
+                case WCS_TV:
+                    call ap_vtol (im, xlist, ylist, xlist, ylist, 1)
+                default:
+                    ;
+                }
+
+		# Move to the next object.
+		newlist = YES
+		if (key == 'm') {
+		    newobject = YES
+		    newsky = YES
+                    goto endswitch_
+		}
+
+		# Measure the next object.
+		ier = apfitsky (ap, im, xlist, ylist, sd, gd)
+		if (id != NULL) {
+		    call apmark (ap, id, NO, apstati (ap, MKSKY), NO)
+		    if (id == gd)
+			call gflush (id)
+		    else
+			call gframe (id)
+		}
+		call ap_splot (ap, stid, gd, apstati (ap, RADPLOTS))
+		if (interactive == YES)
+		    call ap_qspsky (ap, ier)
+		if (stid == 1)
+		    call ap_param (ap, out, "fitsky")
+		call ap_pssky (ap, out, stid, ltid, ier)
+		call ap_splot (ap, stid, mgd, YES)
+		stid = stid + 1
+		newobject = NO
+		newsky = NO
+
+	    # Process the remainder of the list.
+	    case 'l':
+		if (cl != NULL) {
+		    ltid = ltid + 1
+		    oid = stid
+		    call apbsky (ap, im, cl, sd, out, stid, ltid, gd, mgd, id,
+		        YES)
+		    ltid = ltid + stid - oid + 1
+		    if (id != NULL) {
+		        if (id == gd)
+			    call gflush (id)
+		        else
+		            call gframe (id)
+		    }
+		} else if (interactive == YES)
+		    call printf ("No coordinate list\n")
+
+	    default:
+		# do nothing
+		call printf ("Unknown or ambiguous keystroke command\n")
+	    }
+
+endswitch_
+
+	    # Setup for the next object.
+	    key = ' '
+	    Memc[cmd] = EOS
+	    call apsetr (ap, WX, apstatr (ap, CWX))
+	    call apsetr (ap, WY, apstatr (ap, CWY))
+
+	}
+
+	call sfree (sp)
+end
diff --git a/noao/digiphot/apphot/fitsky/apskybuf.x b/noao/digiphot/apphot/fitsky/apskybuf.x
new file mode 100644
index 00000000..cacd4737
--- /dev/null
+++ b/noao/digiphot/apphot/fitsky/apskybuf.x
@@ -0,0 +1,254 @@
+include <imhdr.h>
+include <math.h>
+include <mach.h>
+include "../lib/apphotdef.h"
+include "../lib/fitskydef.h"
+include "../lib/fitsky.h"
+
+# APSKYBUF -- Procedure to fetch the sky pixels given the pointer to the
+# IRAF image, the coordinates of the center and the size of the apphot
+# sky annulus.
+
+int procedure apskybuf (ap, im, wx, wy)
+
+pointer	ap		# pointer to apphot structure
+pointer	im		# pointer to the IRAF image
+real	wx, wy		# center coordinates
+
+int	lenbuf
+pointer	sky
+real	annulus, dannulus, datamin, datamax
+int	ap_skypix(), ap_bskypix()
+
+begin
+	# Check for 0 radius annulus.
+	sky = AP_PSKY(ap)
+	annulus = AP_ANNULUS(sky) * AP_SCALE(ap)
+	dannulus = AP_DANNULUS(sky) * AP_SCALE(ap)
+	if (dannulus <= 0.0)
+	    return (AP_NOSKYAREA)
+
+	# Allocate space for sky pixels.
+	lenbuf = PI * (2.0 * annulus + dannulus + 1.0) * (dannulus + 0.5)
+
+	if (lenbuf != AP_LENSKYBUF(sky)) {
+	    if (AP_SKYPIX(sky) != NULL)
+		call mfree (AP_SKYPIX(sky), TY_REAL)
+	    call malloc (AP_SKYPIX(sky), lenbuf, TY_REAL)
+	    if (AP_COORDS(sky) != NULL)
+		call mfree (AP_COORDS(sky), TY_INT)
+	    call malloc (AP_COORDS(sky), lenbuf, TY_INT)
+	    if (AP_INDEX(sky) != NULL)
+		call mfree (AP_INDEX(sky), TY_INT)
+	    call malloc (AP_INDEX(sky), lenbuf, TY_INT)
+	    if (AP_SWGT(sky) != NULL)
+		call mfree (AP_SWGT(sky), TY_REAL)
+	    call malloc (AP_SWGT(sky), lenbuf, TY_REAL)
+	    AP_LENSKYBUF(sky) = lenbuf
+	}
+
+	# Fetch the sky pixels.
+	if (IS_INDEFR(AP_DATAMIN(ap)) && IS_INDEFR(AP_DATAMAX(ap))) {
+	    AP_NSKYPIX(sky) = ap_skypix (im, wx, wy, annulus, (annulus +
+	        dannulus), Memr[AP_SKYPIX(sky)], Memi[AP_COORDS(sky)],
+		AP_SXC(sky), AP_SYC(sky), AP_SNX(sky), AP_SNY(sky))
+	    AP_NBADSKYPIX(sky) = 0
+	} else {
+	    if (IS_INDEFR(AP_DATAMIN(ap)))
+		datamin = -MAX_REAL
+	    else
+		datamin = AP_DATAMIN(ap)
+	    if (IS_INDEFR(AP_DATAMAX(ap)))
+		datamax = MAX_REAL
+	    else
+		datamax = AP_DATAMAX(ap)
+	    AP_NSKYPIX(sky) = ap_bskypix (im, wx, wy, annulus, (annulus +
+	        dannulus), datamin, datamax, Memr[AP_SKYPIX(sky)],
+		Memi[AP_COORDS(sky)], AP_SXC(sky), AP_SYC(sky), AP_SNX(sky),
+		AP_SNY(sky), AP_NBADSKYPIX(sky))
+	}
+
+	if (AP_NSKYPIX(sky) <= 0) {
+	    if (AP_NBADSKYPIX(sky) <= 0)
+	        return (AP_SKY_OUTOFBOUNDS)
+	    else
+	        return (AP_NSKY_TOO_SMALL)
+	} else
+	    return (AP_OK)
+end
+
+
+# AP_SKYPIX -- Procedure to fetch the sky pixels from the image
+
+int procedure ap_skypix (im, wx, wy, rin, rout, skypix, coords, xc, yc,
+        nx, ny)
+
+pointer	im		# pointer to IRAF image
+real	wx, wy		# center of sky annulus
+real	rin, rout	# inner and outer radius of sky annulus
+real	skypix[ARB]	# skypixels
+int	coords[ARB]	# sky subraster coordinates [i + nx * (j - 1)]
+real	xc, yc		# center of sky subraster
+int	nx, ny		# max dimensions of sky subraster (output)
+
+int	i, j, ncols, nlines, c1, c2, l1, l2, nskypix
+pointer	buf
+real	xc1, xc2, xl1, xl2, rin2, rout2, rj2, r2
+pointer	imgs2r()
+
+#pointer	tbuf
+
+begin
+	if (rout <= rin)
+	    return (0)
+
+	# Test for out of bounds sky regions.
+	ncols = IM_LEN(im,1)
+	nlines = IM_LEN(im,2)
+	xc1 = wx - rout
+	xc2 = wx + rout
+	xl1 = wy - rout
+	xl2 = wy + rout
+	if (xc2 < 1.0 || xc1 > real (ncols) || xl2 < 1.0 || xl1 > real (nlines))
+	    return (0)
+
+	# Compute the column and line limits.
+	c1 = max (1.0, min (real (ncols), wx - rout)) + 0.5
+	c2 = min (real (ncols), max (1.0, wx + rout)) + 0.5
+	l1 = max (1.0, min (real (nlines), wy - rout)) + 0.5
+	l2 = min (real (nlines), max (1.0, wy + rout)) + 0.5
+	nx = c2 - c1 + 1
+	ny = l2 - l1 + 1
+	xc = wx - c1 + 1
+	yc = wy - l1 + 1
+
+	# Fetch the sky pixels.
+	rin2 = rin ** 2
+	rout2 = rout ** 2
+	nskypix = 0
+
+	do j = l1, l2 {
+	    buf = imgs2r (im, c1, c2, j, j)
+	    rj2 = (wy - j) ** 2
+	    do i = c1, c2 {
+	        r2 = (wx - i) ** 2 + rj2
+		if (r2 > rin2 && r2 <= rout2) {
+		    skypix[nskypix+1] = Memr[buf+i-c1]
+		    coords[nskypix+1] = (i - c1 + 1) + nx * (j - l1)
+		    nskypix = nskypix + 1
+		}
+	    }
+	}
+
+	#buf = imgs2r (im, c1, c2, l1, l2)
+	#tbuf = buf
+	#do j = l1,  l2 {
+	    #rj2 = (wy - j) ** 2
+	    #do i = c1, c2 {
+	        #r2 = (wx - i) ** 2 + rj2
+		#if (r2 > rin2 && r2 <= rout2) {
+		    #skypix[nskypix+1] = Memr[tbuf+i-c1]
+		    #coords[nskypix+1] = (i - c1 + 1) + nx * (j - l1)
+		    #nskypix = nskypix + 1
+		#}
+	    #}
+	    #tbuf = tbuf + nx
+	#}
+
+	return (nskypix)
+end
+
+
+# AP_BSKYPIX -- Procedure to fetch the sky pixels from the image
+
+int procedure ap_bskypix (im, wx, wy, rin, rout, datamin, datamax,
+	skypix, coords, xc, yc, nx, ny, nbad)
+
+pointer	im		# pointer to IRAF image
+real	wx, wy		# center of sky annulus
+real	rin, rout	# inner and outer radius of sky annulus
+real	datamin		# minimum good value
+real	datamax		# maximum good value
+real	skypix[ARB]	# skypixels
+int	coords[ARB]	# sky subraster coordinates [i + nx * (j - 1)]
+real	xc, yc		# center of sky subraster
+int	nx, ny		# max dimensions of sky subraster (output)
+int	nbad		# number of bad pixels
+
+int	i, j, ncols, nlines, c1, c2, l1, l2, nskypix
+pointer	buf
+real	xc1, xc2, xl1, xl2, rin2, rout2, rj2, r2, pixval
+pointer	imgs2r()
+
+#pointer	tbuf
+
+begin
+	if (rout <= rin)
+	    return (0)
+
+	# Test for out of bounds sky regions.
+	ncols = IM_LEN(im,1)
+	nlines = IM_LEN(im,2)
+	xc1 = wx - rout
+	xc2 = wx + rout
+	xl1 = wy - rout
+	xl2 = wy + rout
+	if (xc2 < 1.0 || xc1 > real (ncols) || xl2 < 1.0 || xl1 > real (nlines))
+	    return (0)
+
+	# Compute the column and line limits.
+	c1 = max (1.0, min (real (ncols), wx - rout)) + 0.5
+	c2 = min (real (ncols), max (1.0, wx + rout)) + 0.5
+	l1 = max (1.0, min (real (nlines), wy - rout)) + 0.5
+	l2 = min (real (nlines), max (1.0, wy + rout)) + 0.5
+	nx = c2 - c1 + 1
+	ny = l2 - l1 + 1
+	xc = wx - c1 + 1
+	yc = wy - l1 + 1
+
+	rin2 = rin ** 2
+	rout2 = rout ** 2
+	nskypix = 0
+	nbad = 0
+
+	# Fetch the sky pixels.
+	do j = l1, l2 {
+	    buf = imgs2r (im, c1, c2, j, j)
+	    rj2 = (wy - j) ** 2
+	    do i = c1, c2 {
+	        r2 = (wx - i) ** 2 + rj2
+		if (r2 > rin2 && r2 <= rout2) {
+		    pixval = Memr[buf+i-c1] 
+		    if (pixval < datamin || pixval > datamax)
+		        nbad = nbad + 1
+		    else {
+		        skypix[nskypix+1] = pixval
+		        coords[nskypix+1] = (i - c1 + 1) + nx * (j - l1)
+		        nskypix = nskypix + 1
+		    }
+		}
+	    }
+	}
+
+	#buf = imgs2r (im, c1, c2, l1, l2)
+	#tbuf = buf
+	#do j = l1, l2 {
+	    #rj2 = (wy - j) ** 2
+	    #do i = c1, c2 {
+	        #r2 = (wx - i) ** 2 + rj2
+		#if (r2 > rin2 && r2 <= rout2) {
+		    #pixval = Memr[tbuf+i-c1] 
+		    #if (pixval < datamin || pixval > datamax)
+		        #nbad = nbad + 1
+		    #else {
+		        #skypix[nskypix+1] = pixval
+		        #coords[nskypix+1] = (i - c1 + 1) + nx * (j - l1)
+		        #nskypix = nskypix + 1
+		    #}
+		#}
+	    #}
+	    #tbuf = tbuf + nx
+	#}
+
+	return (nskypix)
+end
diff --git a/noao/digiphot/apphot/fitsky/apskycolon.x b/noao/digiphot/apphot/fitsky/apskycolon.x
new file mode 100644
index 00000000..35b59aa9
--- /dev/null
+++ b/noao/digiphot/apphot/fitsky/apskycolon.x
@@ -0,0 +1,367 @@
+include "../lib/apphot.h"
+include "../lib/noise.h"
+include "../lib/fitsky.h"
+include "../lib/display.h"
+
+
+# APSKYCOLON -- Procedure to process the fitsky colon commands.
+
+procedure apskycolon (ap, im, cl, out, stid, ltid, cmdstr, newimage,
+	newskybuf, newsky)
+
+pointer	ap				# pointer to the apphot structure
+pointer	im				# pointer to the iraf image
+int	cl				# coordinate file descriptor
+int	out				# output file descriptor
+int	stid				# output file sequence number
+int	ltid				# coord list sequence number
+char	cmdstr[ARB]			# command string
+int	newimage			# new image ?
+int	newskybuf			# new sky buffer ?
+int	newsky				# new sky fit ?
+
+int	junk
+pointer	sp, incmd, outcmd
+int	strdic()
+
+begin
+	# Get the command.
+	call smark (sp)
+	call salloc (incmd, SZ_LINE, TY_CHAR)
+	call salloc (outcmd, SZ_LINE, TY_CHAR)
+	call sscan (cmdstr)
+	call gargwrd (Memc[incmd], SZ_LINE)
+	if (Memc[incmd] == EOS) {
+	    call sfree (sp)
+	    return
+	}
+
+	# Process the command.
+	if (strdic (Memc[incmd], Memc[outcmd], SZ_LINE, SCMDS) != 0)
+	    call apscolon (ap, out, stid, cmdstr, newskybuf, newsky)
+	else if (strdic (Memc[incmd], Memc[outcmd], SZ_LINE, APCMDS) != 0)
+	    call ap_apcolon (ap, im, cl, out, stid, ltid, cmdstr,
+	        newimage, junk, junk, newskybuf, newsky, junk, junk)
+	else if (strdic (Memc[incmd], Memc[outcmd], SZ_LINE, NCMDS) != 0)
+	    call apnscolon (ap, im, out, stid, cmdstr, junk, junk,
+	        newskybuf, newsky, junk, junk)
+	else
+	    call ap_simcolon (ap, cmdstr)
+
+	call sfree (sp)
+end
+
+
+# APSCOLON --  Procedure to examine and edit the sky fitting parameters.
+
+procedure apscolon (ap, out, stid, cmdstr, newbuf, newfit)
+
+pointer	ap		# pointer to the apphot structure
+int	out		# output file descriptor
+int	stid		# output file number
+char	cmdstr		# command string
+int	newbuf		# new sky buffer
+int	newfit		# new sky fit
+
+bool	bval
+int	ncmd, ival, stat
+pointer	sp, cmd
+real	rval
+
+bool	itob()
+int	nscan(), strdic(), btoi(), apstati()
+real	apstatr()
+
+
+begin
+	# Get the command
+	call smark (sp)
+	call salloc (cmd, SZ_LINE, TY_CHAR)
+	call sscan (cmdstr)
+	call gargwrd (Memc[cmd], SZ_LINE)
+	if (Memc[cmd] == EOS) {
+	    call sfree (sp)
+	    return
+	}
+
+	# Process the command.
+	ncmd = strdic (Memc[cmd], Memc[cmd], SZ_LINE, SCMDS)
+	switch (ncmd) {
+	case SCMD_ANNULUS:
+	    call gargr (rval)
+	    if (nscan() == 1) {
+		call printf ("%s = %g %s\n")
+		    call pargstr (KY_ANNULUS)
+		    call pargr (apstatr (ap, ANNULUS))
+		    call pargstr (UN_SSCALEUNIT)
+	    } else {
+		call apsetr (ap, ANNULUS, rval)
+		if (stid > 1)
+		    call ap_rparam (out, KY_ANNULUS, rval, UN_SSCALEUNIT,
+			"inner radius of sky annulus")
+		newbuf = YES
+		newfit = YES
+	    }
+	case SCMD_DANNULUS:
+	    call gargr (rval)
+	    if (nscan() == 1) {
+		call printf ("%s = %g %s\n")
+		    call pargstr (KY_DANNULUS)
+		    call pargr (apstatr (ap, DANNULUS))
+		    call pargstr (UN_SSCALEUNIT)
+	    } else {
+		call apsetr (ap, DANNULUS, rval)
+		if (stid > 1)
+		    call ap_rparam (out, KY_DANNULUS, rval, UN_SSCALEUNIT,
+			"width of the sky annulus")
+		newbuf = YES
+		newfit = YES
+	    }
+	case SCMD_SALGORITHM:
+	    call gargwrd (Memc[cmd], SZ_LINE)
+	    if (Memc[cmd] == EOS) {
+		call apstats (ap, SSTRING, Memc[cmd], SZ_FNAME)
+	        call printf ("%s = %s\n")
+		    call pargstr (KY_SSTRING)
+		    call pargstr (Memc[cmd])
+	    } else {
+		stat = strdic (Memc[cmd], Memc[cmd], SZ_LINE, SFUNCS)
+		if (stat > 0) {
+		    call apseti (ap, SKYFUNCTION, stat)
+		    call apsets (ap, SSTRING, Memc[cmd])
+		    if (stid > 1)
+		        call ap_sparam (out, KY_SSTRING, Memc[cmd],
+			    UN_SALGORITHM, "sky fitting algorithm")
+		    newfit = YES
+		}
+	    }
+	case SCMD_KHIST:
+	    call gargr (rval)
+	    if (nscan() == 1) {
+		call printf ("%s = %g %s\n")
+		    call pargstr (KY_K1)
+		    call pargr (apstatr (ap, K1))
+		    call pargstr (UN_SSIGMA)
+	    } else {
+		call apsetr (ap, K1, rval)
+		if (stid > 1)
+		    call ap_rparam (out, KY_K1, rval, UN_SSIGMA,
+			"half width of sky histogram")
+		newfit = YES
+	    }
+	case SCMD_SLOREJECT:
+	    call gargr (rval)
+	    if (nscan() == 1) {
+		call printf ("%s = %g %s\n")
+		    call pargstr (KY_SLOREJECT)
+		    call pargr (apstatr (ap, SLOREJECT))
+		    call pargstr (UN_SSIGMA)
+	    } else {
+		call apsetr (ap, SLOREJECT, rval)
+		if (stid > 1)
+		    call ap_rparam (out, KY_SLOREJECT, rval, UN_SSIGMA,
+			"lower k-sigma rejection criterion")
+		newfit = YES
+	    }
+	case SCMD_SHIREJECT:
+	    call gargr (rval)
+	    if (nscan() == 1) {
+		call printf ("%s = %g %s\n")
+		    call pargstr (KY_SHIREJECT)
+		    call pargr (apstatr (ap, SHIREJECT))
+		    call pargstr (UN_SSIGMA)
+	    } else {
+		call apsetr (ap, SHIREJECT, rval)
+		if (stid > 1)
+		    call ap_rparam (out, KY_SHIREJECT, rval, UN_SSIGMA,
+			"upper k-sigma rejection criterion")
+		newfit = YES
+	    }
+	case SCMD_SLOCLIP:
+	    call gargr (rval)
+	    if (nscan() == 1) {
+		call printf ("%s = %g %s\n")
+		    call pargstr (KY_SLOCLIP)
+		    call pargr (apstatr (ap, SLOCLIP))
+		    call pargstr (UN_SPERCENT)
+	    } else {
+		call apsetr (ap, SLOCLIP, rval)
+		if (stid > 1)
+		    call ap_rparam (out, KY_SLOCLIP, rval, UN_SPERCENT,
+			"lower k-sigma rejection criterion")
+		newfit = YES
+	    }
+	case SCMD_SHICLIP:
+	    call gargr (rval)
+	    if (nscan() == 1) {
+		call printf ("%s = %g %s\n")
+		    call pargstr (KY_SHICLIP)
+		    call pargr (apstatr (ap, SHICLIP))
+		    call pargstr (UN_SPERCENT)
+	    } else {
+		call apsetr (ap, SHICLIP, rval)
+		if (stid > 1)
+		    call ap_rparam (out, KY_SHICLIP, rval, UN_SPERCENT,
+			"lower k-sigma rejection criterion")
+		newfit = YES
+	    }
+	case SCMD_SMAXITER:
+	    call gargi (ival)
+	    if (nscan () == 1) {
+		call printf ("%s = %d\n")
+		    call pargstr (KY_SMAXITER)
+		    call pargi (apstati (ap, SMAXITER))
+	    } else {
+		call apseti (ap, SMAXITER, ival)
+		if (stid > 1)
+		    call ap_iparam (out, KY_SMAXITER, ival, UN_SNUMBER,
+			"maximum number of iterations")
+		newfit = YES
+	    }
+	case SCMD_BINSIZE:
+	    call gargr (rval)
+	    if (nscan() == 1) {
+		call printf ("%s = %g %s\n")
+		    call pargstr (KY_BINSIZE)
+		    call pargr (apstatr (ap, BINSIZE))
+		    call pargstr (UN_SSIGMA)
+	    } else {
+		call apsetr (ap, BINSIZE, rval)
+		if (stid > 1)
+		    call ap_rparam (out, KY_BINSIZE, rval, UN_SSIGMA,
+			"width of the sky histogram bin")
+		newfit = YES
+	    }
+	case SCMD_SMOOTH:
+	    call gargb (bval)
+	    if (nscan () == 1) {
+		call printf ("%s = %b\n")
+		    call pargstr (KY_SMOOTH)
+		    call pargb (itob (apstati (ap, SMOOTH)))
+	    } else {
+		call apseti (ap, SMOOTH, btoi (bval))
+		if (stid > 1)
+		    call ap_bparam (out, KY_SMOOTH, bval, UN_SSWITCH,
+			"Lucy smooth the histogram")
+		newfit = YES
+	    }
+	case SCMD_RGROW:
+	    call gargr (rval)
+	    if (nscan() == 1) {
+		call printf ("%s = %g %s\n")
+		    call pargstr (KY_RGROW)
+		    call pargr (apstatr (ap, RGROW))
+		    call pargstr (UN_SSCALEUNIT)
+	    } else {
+		call apsetr (ap, RGROW, rval)
+		if (stid > 1)
+		    call ap_rparam (out, KY_RGROW, rval, UN_SSCALEUNIT,
+			"region growing radius")
+		newfit = YES
+	    }
+	case SCMD_SNREJECT:
+	    call gargi (ival)
+	    if (nscan () == 1) {
+		call printf ("%s = %d\n")
+		    call pargstr (KY_SNREJECT)
+		    call pargi (apstati (ap, SNREJECT))
+	    } else {
+		call apseti (ap, SNREJECT, ival)
+		if (stid > 1)
+		    call ap_iparam (out, KY_SNREJECT, ival, UN_SNUMBER,
+			"maximum number of rejection cycles")
+		newfit = YES
+	    }
+	case SCMD_SKYVALUE:
+	    call gargr (rval)
+	    if (nscan () == 1) {
+		call printf ("%s = %g\n")
+		    call pargstr (KY_SKY_BACKGROUND)
+		    call pargr (apstatr (ap, SKY_BACKGROUND))
+		    call pargstr (UN_SCOUNTS)
+	    } else {
+		call apsetr (ap, SKY_BACKGROUND, rval)
+		if (stid > 1)
+		    call ap_rparam (out, KY_SKY_BACKGROUND, rval,
+		        UN_SCOUNTS, "user supplied sky value")
+		newfit = YES
+	    }
+	case SCMD_MKSKY:
+	    call gargb (bval)
+	    if (nscan () == 1) {
+		call printf ("%s = %b\n")
+		    call pargstr (KY_MKSKY)
+		    call pargb (itob (apstati (ap, MKSKY)))
+	    } else {
+		call apseti (ap, MKSKY, btoi (bval))
+	    }
+	default:
+	    # do nothing gracefully
+	    call printf ("Unrecognized command\7\n")
+	}
+
+	call sfree (sp)
+end
+
+
+# AP_SIMCOLON -- Procedure to process fitsky commands which alter parameters
+# other than the sky fitting parameters themselves.
+
+procedure ap_simcolon (ap, cmdstr)
+
+pointer	ap			# pointer to the apphot structure
+char	cmdstr[ARB]		# command string
+
+bool	bval
+int	ncmd
+pointer	sp, cmd
+bool	itob()
+int	strdic(), nscan(), apstati(), btoi()
+
+begin
+	call smark (sp)
+	call salloc (cmd, SZ_LINE, TY_CHAR)
+		
+	# Get the command.
+	call sscan (cmdstr)
+	call gargwrd (Memc[cmd], SZ_LINE)
+	if (Memc[cmd] == EOS) {
+	    call sfree (sp)
+	    return
+	}
+
+	# Process the commands.
+	ncmd = strdic (Memc[cmd], Memc[cmd], SZ_LINE, MISC)
+	switch (ncmd) {
+	case ACMD_SHOW:
+	    call gargwrd (Memc[cmd], SZ_LINE)
+	    ncmd = strdic (Memc[cmd], Memc[cmd], SZ_LINE, SSHOWARGS)
+	    switch (ncmd) {
+	    case SCMD_DATA:
+		call printf ("\n")
+		call ap_nshow (ap)
+		call printf ("\n")
+	    case SCMD_SKY:
+		call printf ("\n")
+	        call ap_spshow (ap)
+		call printf ("\n")
+	    default:
+		call printf ("\n")
+	        call ap_sshow (ap)
+		call printf ("\n")
+	    }
+	case ACMD_RADPLOTS:
+	    call gargb (bval)
+	    if (nscan () == 1) {
+		call printf ("%s = %b\n")
+		    call pargstr (KY_RADPLOTS)
+		    call pargb (itob (apstati (ap, RADPLOTS)))
+	    } else {
+		call apseti (ap, RADPLOTS, btoi (bval))
+	    }
+	default:
+	    call printf ("Unknown or ambiguous colon command\7\n")
+	}
+
+	call sfree (sp)
+end
diff --git a/noao/digiphot/apphot/fitsky/apsplot.x b/noao/digiphot/apphot/fitsky/apsplot.x
new file mode 100644
index 00000000..0a75b0c8
--- /dev/null
+++ b/noao/digiphot/apphot/fitsky/apsplot.x
@@ -0,0 +1,244 @@
+include <pkg/gtools.h>
+include <gset.h>
+include "../lib/apphotdef.h"
+include "../lib/apphot.h"
+include "../lib/noise.h"
+include "../lib/fitskydef.h"
+include "../lib/fitsky.h"
+
+# AP_SPLOT -- Procedure to compute radial profile plots for the sky fitting
+# routine.
+
+procedure ap_splot (ap, sid, gd, makeplot)
+
+pointer	ap		# pointer to the apphot structure
+int	sid		# id number of the star
+pointer	gd		# graphics stream
+int	makeplot	# make a plot
+
+int	nx, ny, nskypix
+pointer	sp, sky, str, r, gt
+real	xcenter, ycenter, rmin, rmax, imin, imax
+real	u1, u2, v1, v2, x1, x2, y1, y2
+int	apstati()
+pointer	ap_gtinit()
+real	apstatr()
+
+begin
+	# Initialize.
+	if (gd == NULL || makeplot == NO)
+	    return
+
+	# Check for defined center and non-constant algorithm.
+	xcenter = apstatr (ap, SXCUR)
+	ycenter = apstatr (ap, SYCUR)
+	if (IS_INDEFR(xcenter) || IS_INDEFR(ycenter))
+	    return
+	if (apstati (ap, SKYFUNCTION) == AP_CONSTANT)
+	    return
+
+	# Check that a buffer of sky pixels exists.
+	sky = AP_PSKY(ap)
+	nskypix = AP_NSKYPIX(sky)
+	nx = AP_SNX(sky)
+	ny = AP_SNY(sky)
+	if (nskypix <= 0 || nx <= 0 || ny <= 0)
+	    return
+
+	# Allocate working space
+	call smark (sp)
+	call salloc (str, SZ_LINE, TY_CHAR)
+	call salloc (r, nskypix, TY_REAL)
+
+	# Compute the radii and the plot limits.
+	call ap_xytor (Memi[AP_COORDS(sky)], Memi[AP_INDEX(sky)],
+	    Memr[r], nskypix, AP_SXC(sky), AP_SYC(sky), nx)
+	call alimr (Memr[r], nskypix, rmin, rmax)
+	rmin = rmin - 1.0
+	rmax = rmax + 1.0
+	call alimr (Memr[AP_SKYPIX(sky)], nskypix, imin, imax)
+
+	# Reactivate the work station.
+	call greactivate (gd, 0)
+
+	# Store the viewport and window coordinates.
+	call ggview (gd, u1, u2, v1, v2)
+	call ggwind (gd, x1, x2, y1, y2)
+
+	# Initialize the plot.
+	call apstats (ap, IMROOT, Memc[str], SZ_LINE)
+	call sprintf (Memc[str], SZ_LINE, "%s  Star %d")
+	    call pargstr (Memc[str])
+	    call pargi (sid)
+	gt = ap_gtinit (Memc[str], apstatr (ap,OSXCUR), apstatr(ap,OSYCUR))
+	
+	# Draw the plot.
+	call gclear (gd)
+	call ap_spset (gd, gt, ap, rmin, rmax, imin, imax)
+	call ap_spannotate (gd, ap, rmin, rmax, imin, imax)
+	call ap_plotrad (gd, gt, Memr[r], Memr[AP_SKYPIX(sky)], nskypix, "plus")
+
+	# Restore the viewport and window coordinates.
+	call gsview (gd, u1, u2, v1, v2)
+	call gswind (gd, x1, x2, y1, y2)
+
+	# Free the space.
+	call ap_gtfree (gt)
+	call gdeactivate (gd, 0)
+	call sfree (sp)
+end
+
+
+# AP_SPSET -- Procedure to set up the parameters for the fitsky radial profile
+# plot.
+
+procedure ap_spset (gd, gt, ap, xmin, xmax, ymin, ymax)
+
+pointer	gd		# graphics stream
+pointer	gt		# gtools pointer
+pointer	ap		# apphot pointer
+real	xmin, xmax	# minimum and maximum radial distance
+real	ymin, ymax	# minimum and maximum of the y axis
+
+int	fd
+pointer	sp, str, title
+real	aspect, scale, vx1, vx2, vy1, vy2
+int	apstati(), stropen()
+real	apstatr(), gstatr()
+
+begin
+	call smark (sp)
+	call salloc (str, 3 * SZ_LINE, TY_CHAR)
+	call salloc (title, SZ_LINE, TY_CHAR)
+
+	# Encode the parameter string.
+	fd = stropen (Memc[str], 3 * SZ_LINE, WRITE_ONLY)
+
+	call sysid (Memc[title], SZ_FNAME)
+	call fprintf (fd, "%s\n")
+	    call pargstr (Memc[title])
+
+	call fprintf (fd,
+	    "Sky: value=%0.2f sigma=%0.2f skew=%0.2f nsky=%d nreject=%d\n")
+	    call pargr (apstatr (ap, SKY_MODE))
+	    call pargr (apstatr (ap, SKY_SIGMA))
+	    call pargr (apstatr (ap, SKY_SKEW))
+	    call pargi (apstati (ap, NSKY))
+	    call pargi (apstati (ap, NSKY_REJECT))
+
+	call gt_gets (gt, GTTITLE, Memc[title], SZ_LINE)
+	call fprintf (fd, "%s\n")
+	    call pargstr (Memc[title])
+
+	call strclose (fd)
+
+	# Set the aspect ratio.
+	scale = apstatr (ap, SCALE)
+	aspect = gstatr (gd, G_ASPECT)
+	call gsetr (gd, G_ASPECT, 0.75)
+
+	# Set the labels and window.
+	call gseti (gd, G_XDRAWAXES, 2)
+	call gswind (gd, xmin / scale, xmax / scale, ymin, ymax)
+	call glabax (gd, Memc[str], "", "Intensity")
+	call gseti (gd, G_YDRAWAXES, 0)
+	call gseti (gd, G_XDRAWAXES, 1)
+	call ggview (gd, vx1, vx2, vy1, vy2)
+	call gsview (gd, vx1, vx2, vy1, vy2)
+	call gswind (gd, xmin, xmax, ymin, ymax)
+	call glabax (gd, "",
+	    "Radial Distance (lower-pixels, upper-scale units)", "")
+
+	call gseti (gd, G_YDRAWAXES, 3)
+	call gseti (gd, G_XDRAWAXES, 3)
+	call gsetr (gd, G_ASPECT, aspect)
+	call gt_sets (gt, GTTYPE, "mark")
+
+	call sfree (sp)
+end
+
+
+# AP_SPANNOTATE -- Procedure to annotate the radial plot in fitsky.
+
+procedure ap_spannotate (gd, ap, xmin, xmax, ymin, ymax)
+
+pointer	gd		# graphics stream
+pointer	ap		# apphot structure
+real	xmin, xmax	# min and max of x axis
+real	ymin, ymax	# min and max of y axis
+
+pointer	sp, str
+real	annulus, dannulus, sigma, skyval, skysigma
+real	apstatr ()
+
+begin
+	call smark (sp)
+	call salloc (str, SZ_LINE, TY_CHAR)
+	call gseti (gd, G_PLTYPE, GL_DASHED)
+
+	# Mark the inner sky annulus.
+	annulus = apstatr (ap, SCALE) * apstatr (ap, ANNULUS)
+	if (annulus >= xmin && annulus <= xmax) {
+	    call gamove (gd, annulus, ymin)
+	    call gadraw (gd, annulus, ymax)
+	    call sprintf (Memc[str], SZ_LINE, "inner sky radius = %0.2f")
+	        call pargr (annulus)
+	    call gtext (gd, annulus, ymax, Memc[str], "q=h;u=180;v=t;p=r")
+	}
+ 
+	# Mark the outer sky annulus.
+	dannulus = annulus + apstatr (ap, SCALE) * apstatr (ap, DANNULUS)
+	if (dannulus >= xmin && dannulus <= xmax) {
+	    call gamove (gd, dannulus, ymin)
+	    call gadraw (gd, dannulus, ymax)
+	    call sprintf (Memc[str], SZ_LINE, "outer sky radius = %0.2f")
+	        call pargr (dannulus)
+	    call gtext (gd, dannulus, ymax, Memc[str], "q=h;u=180;v=t;p=r")
+	}
+
+	# Mark the sky sigma if defined.
+	sigma = apstatr (ap, SKY_SIGMA)
+	if (! IS_INDEFR(sigma)) {
+	    call gmark (gd, (xmin + xmax) / 2.0, (ymin + ymax) / 2.0, 
+		GM_VEBAR, -0.25, -sigma)
+	    call sprintf (Memc[str], SZ_LINE, "sigma = %g")
+		call pargr (sigma)
+	    call gtext (gd, (xmin + xmax) / 2.0, (ymin + ymax + sigma) / 2.0,
+		Memc[str], "q=h;h=c")
+	}
+
+	# Mark the sky value.
+	call gseti (gd, G_PLTYPE, GL_SOLID)
+	skyval = apstatr (ap, SKY_MODE)
+	if (skyval >= ymin && skyval <= ymax) {
+	    call gamove (gd, xmin, skyval)
+	    call gadraw (gd, xmax, skyval)
+	}
+
+	# Mark the upper sky sigma.
+	call gseti (gd, G_PLTYPE, GL_DASHED)
+	if (! IS_INDEFR(apstatr (ap, SKY_SIGMA)))
+	    skysigma = skyval + apstatr (ap, SHIREJECT) * apstatr (ap,
+	        SKY_SIGMA)
+	else
+	    skysigma = INDEFR
+	if (! IS_INDEFR(skysigma) && (skysigma >= ymin) && skysigma <= ymax) {
+	    call gamove (gd, xmin, skysigma)
+	    call gadraw (gd, xmax, skysigma)
+	    #call sprintf (Memc[str], SZ_LINE, "sky sigma= %g")
+	        #call pargr (skysigma)
+	}
+
+	# Mark the lower sky sigma
+	if (! IS_INDEFR(apstatr (ap, SKY_SIGMA)))
+	    skysigma = skyval - apstatr (ap, SLOREJECT) * apstatr (ap,
+	        SKY_SIGMA)
+	else
+	    skysigma = INDEFR
+	if (! IS_INDEFR(skysigma) && (skysigma >= ymin) && skysigma <= ymax) {
+	    call gamove (gd, xmin, skysigma)
+	    call gadraw (gd, xmax, skysigma)
+	}
+
+	call sfree (sp)
+end
diff --git a/noao/digiphot/apphot/fitsky/apsradsetup.x b/noao/digiphot/apphot/fitsky/apsradsetup.x
new file mode 100644
index 00000000..fd4039f8
--- /dev/null
+++ b/noao/digiphot/apphot/fitsky/apsradsetup.x
@@ -0,0 +1,97 @@
+include "../lib/display.h"
+include "../lib/fitsky.h"
+
+define	HELPFILE	"apphot$fitsky/ifitsky.key"
+
+# AP_SRADSETUP -- Procedure to set up the sky fitting interactively using
+# radial profile plot around the given coordinates.
+
+procedure ap_sradsetup (ap, im, wx, wy, gd, out, stid)
+
+pointer	ap			# pointer to apphot structure
+pointer	im			# pointero to the IRAF image
+real	wx, wy			# cursor coordinates
+pointer	gd			# pointer to graphics stream
+int	out			# output file descriptor
+int	stid			# output file sequence number
+
+int	ier, key, wcs
+pointer	sp, cmd
+real	xcenter, ycenter, xc, yc, rmin, rmax, imin, imax, rval
+real	u1, u2, v1, v2, x1, x2, y1, y2
+
+int	apstati(), apfitsky(), clgcur(), ap_showplot()
+real	apstatr(), ap_cannulus(), ap_cdannulus(), ap_csigma()
+real	ap_cdatamin(), ap_cdatamax(), ap_crgrow()
+
+begin
+	if (gd == NULL)
+	    return
+	call greactivate (gd, 0)
+
+	# Store the old window and viewport coordinates.
+	call ggview (gd, u1, u2, v1, v2)
+	call ggwind (gd, x1, x2, y1, y2)
+
+	# Plot the profile.
+	if (ap_showplot (ap, im, wx, wy, gd, xcenter, ycenter, rmin, rmax,
+    	    imin, imax) == ERR) {
+	    call gdeactivate (gd, 0)
+	    return
+	}
+
+	# Allocate memory.
+	call smark (sp)
+	call salloc (cmd, SZ_LINE, TY_CHAR)
+
+	call printf (
+	    "Waiting for setup menu command (?=help, v=default setup, q=quit):")
+	while (clgcur ("gcommands", xc, yc, wcs, key, Memc[cmd],
+	    SZ_LINE) != EOF) {
+
+	switch (key) {
+
+	    case 'q':
+	        break
+	    case '?':
+		call gpagefile (gd, HELPFILE, "")
+	    case 's':
+	        rval = ap_csigma (ap, gd, out, stid, rmin, rmax, imin, imax)
+	    case 'l':
+	        rval = ap_cdatamin (ap, gd, out, stid, rmin, rmax, imin, imax)
+	    case 'u':
+	        rval = ap_cdatamax (ap, gd, out, stid, rmin, rmax, imin, imax)
+	    case 'a':
+		rval = ap_cannulus (ap, gd, out, stid, rmin, rmax, imin, imax)
+	    case 'd':
+		rval = ap_cdannulus (ap, gd, out, stid, apstatr (ap, ANNULUS),
+		    rmin, rmax, imin, imax)
+	    case 'g':
+		rval = ap_crgrow (ap, gd, out, stid, rmin, rmax, imin, imax)
+	    case 'v':
+		rval = ap_cannulus (ap, gd, out, stid, rmin, rmax, imin, imax)
+		rval = ap_cdannulus (ap, gd, out, stid, apstatr (ap, ANNULUS),
+		    rmin, rmax, imin, imax)
+	        rval = ap_csigma (ap, gd, out, stid, rmin, rmax, imin, imax)
+	    default:
+		call printf ("Unknown or ambiguous keystroke command\007\n")
+	    }
+	    call printf (
+	  "Waiting for setup menu command (?=help, v=default setup, q=quit):")
+	}
+	call printf (
+	    "Interactive setup is complete. Type w to store parameters.\n")
+
+	# Store the old window and viewport coordinates.
+	call gsview (gd, u1, u2, v1, v2)
+	call gswind (gd, x1, x2, y1, y2)
+
+	# Free the plotting space.
+	call sfree (sp)
+	call gdeactivate (gd, 0)
+
+	# Fit the new sky value and print it on the standard output.
+	ier = apfitsky (ap, im, xcenter, ycenter, NULL, gd)
+	call ap_splot (ap, 0, gd, apstati (ap, RADPLOTS))
+	call ap_qspsky (ap, ier)
+end
diff --git a/noao/digiphot/apphot/fitsky/apsshow.x b/noao/digiphot/apphot/fitsky/apsshow.x
new file mode 100644
index 00000000..da54bfbf
--- /dev/null
+++ b/noao/digiphot/apphot/fitsky/apsshow.x
@@ -0,0 +1,99 @@
+include "../lib/display.h"
+include "../lib/fitsky.h"
+
+
+# AP_SSHOW -- Procedure to print sky fitting parameters on the terminal.
+
+procedure ap_sshow (ap)
+
+pointer	ap	# pointer to the apphot strucuture
+
+bool	itob()
+int	apstati()
+
+begin
+	call ap_nshow (ap)
+	call printf ("\n")
+	call ap_spshow (ap)
+	call printf ("    %s = %b\n")
+	    call pargstr (KY_RADPLOTS)
+	    call pargb (itob (apstati (ap, RADPLOTS)))
+end
+
+
+# AP_SPSHOW -- Procedure to print sky fitting parameters on the terminal.
+
+procedure ap_spshow (ap)
+
+pointer	ap	# pointer to the apphot strucuture
+
+pointer	sp, str
+bool	itob()
+int	apstati()
+real	apstatr()
+
+begin
+	# Print the image characteristics
+	call smark (sp)
+	call salloc (str, SZ_LINE, TY_CHAR)
+
+	# Print the sky fitting parameters.
+	call printf ("Sky Fitting Parameters\n")
+	call apstats (ap, SSTRING, Memc[str], SZ_FNAME)
+	call printf ("    %s = %s %s    %s = %g %s\n")
+	    call pargstr (KY_SSTRING)
+	    call pargstr (Memc[str])
+	    call pargstr (UN_SALGORITHM)
+	    call pargstr (KY_SKY_BACKGROUND)
+	    call pargr (apstatr (ap, SKY_BACKGROUND))
+	    call pargstr (UN_SCOUNTS)
+
+	call printf ("    %s = %g %s    %s = %g %s\n")
+	    call pargstr (KY_ANNULUS)
+	    call pargr (apstatr (ap, ANNULUS))
+	    call pargstr (UN_SSCALEUNIT)
+	    call pargstr (KY_DANNULUS)
+	    call pargr (apstatr (ap, DANNULUS))
+	    call pargstr (UN_SSCALEUNIT)
+
+	call printf ("    %s = %g %s    %s = %g %s    %s = %b\n")
+	    call pargstr (KY_K1)
+	    call pargr (apstatr (ap, K1))
+	    call pargstr (UN_SSIGMA)
+	    call pargstr (KY_BINSIZE)
+	    call pargr (apstatr (ap, BINSIZE))
+	    call pargstr (UN_SSIGMA)
+	    call pargstr (KY_SMOOTH)
+	    call pargb (itob (apstati (ap, SMOOTH)))
+
+	call printf ("    %s = %g %s    %s = %g %s\n")
+	    call pargstr (KY_SLOCLIP)
+	    call pargr (apstatr (ap, SLOCLIP))
+	    call pargstr (UN_SPERCENT)
+	    call pargstr (KY_SHICLIP)
+	    call pargr (apstatr (ap, SHICLIP))
+	    call pargstr (UN_SPERCENT)
+
+	call printf ("    %s = %g %s    %s = %g %s    %s = %d\n")
+	    call pargstr (KY_SLOREJECT)
+	    call pargr (apstatr (ap, SLOREJECT))
+	    call pargstr (UN_SSIGMA)
+	    call pargstr (KY_SHIREJECT)
+	    call pargr (apstatr (ap, SHIREJECT))
+	    call pargstr (UN_SSIGMA)
+	    call pargstr (KY_SMAXITER)
+	    call pargi (apstati (ap, SMAXITER))
+
+	call printf ("    %s = %d    %s = %g %s\n")
+	    call pargstr (KY_SNREJECT)
+	    call pargi (apstati (ap, SNREJECT))
+	    call pargstr (KY_RGROW)
+	    call pargr (apstatr (ap, RGROW))
+	    call pargstr (UN_SSCALEUNIT)
+
+	call printf ("    %s = %b\n")
+	    call pargstr (KY_MKSKY)
+	    call pargb (itob (apstati (ap, MKSKY)))
+
+	call sfree (sp)
+end
diff --git a/noao/digiphot/apphot/fitsky/fitsky.key b/noao/digiphot/apphot/fitsky/fitsky.key
new file mode 100644
index 00000000..ee515bf1
--- /dev/null
+++ b/noao/digiphot/apphot/fitsky/fitsky.key
@@ -0,0 +1,81 @@
+	Interactive Keystroke Commands
+
+?	Print help
+:	Colon commands
+v	Verify the critical parameters
+w	Save the current parameters
+d	Plot radial profile of current star 
+i	Interactively set parameters using current star
+f	Fit sky for current star
+spbar	Fit sky for current star, output results
+m	Move to next star in coordinate list
+m	Fit sky for next star in coordinate list, output results
+l	Fit sky for remaining stars in coordinate list, output results
+e	Print error messages
+r	Rewind the coordinate list
+q	Exit task
+
+
+        Colon commands
+
+:show	[data/sky]	List the parameters
+:m [n]	Move to the next [nth] star in coordinate list
+:n [n]	Fit sky to next [nth] star in coordinate list, output results
+
+	Colon Parameter Editing Commands
+
+# Image and file name parameters
+
+:image		[string]	Image name
+:coords		[string]	Coordinate file name
+:output 	[string]	Output file name
+
+# Data dependent parameters
+
+:scale		[value]		Image scale (units per pixel)
+:fwhmpsf	[value]		Full width half maximum PSF (scale units)
+:emission	[y/n]		Emission feature (y), absorption (n)
+:sigma		[value]		Standard deviation of sky (counts)
+:datamin	[value]		Minimum good pixel value (counts)
+:datamax	[value]		Maximum good pixel value (counts)
+
+# Noise parameters
+
+:noise		[string]	Noise model (constant|poisson)
+:gain		[string]	Gain image header keyword
+:ccdread	[string]	Readout noise image header keyword
+:epadu		[value]		Gain (electrons per adu)
+:readnoise	[value]		Readout noise (electrons)
+
+# Observations parameters
+
+:exposure	[string]	Exposure time image header keyword
+:airmass	[string]	Airmass image header keyword
+:filter		[string]	Filter image header keyword
+:obstime	[string]	Time of observation image header keyword
+:itime		[value]		Exposure time (time units)
+:xairmass	[value]		Airmass value (number)
+:ifilter	[string]	Filter id string
+:otime		[string]	Time of observation (time units)
+
+# Sky fitting algorithm parameters
+
+:salgorithm	[string]	Sky fitting algorithm 
+:skyvalue	[value]		User supplied sky value (counts)
+:annulus 	[value]		Inner radius of sky annulus (scale units)
+:dannulus	[value]		Width of sky annulus (scale units)
+:khist		[value]		Sky histogram extent (+/- sky sigma)
+:smooth		[y/n]		Lucy smooth the sky histogram 
+:binsize	[value]		Resolution of sky histogram (sky sigma)
+:smaxiter	[value]		Maximum number of iterations
+:sloclip	[value]		Low side clipping factor (percent)
+:shiclip	[value]		High side clipping factor (percent)
+:snreject	[value]		Maximum number of rejection cycles
+:sloreject	[value]		Low side pixel rejection limits (sky sigma)
+:shireject	[value]		High side pixel rejection limits (sky sigma)
+:rgrow		[value]		Region growing radius (scale units)
+
+# Marking and plotting parameters
+
+:mksky		[y/n]		Mark sky annuli on the display
+:radplot	[y/n]		Plot radial profile of sky pixels
diff --git a/noao/digiphot/apphot/fitsky/ifitsky.key b/noao/digiphot/apphot/fitsky/ifitsky.key
new file mode 100644
index 00000000..bd651bc3
--- /dev/null
+++ b/noao/digiphot/apphot/fitsky/ifitsky.key
@@ -0,0 +1,11 @@
+                      Interactive Fitsky Setup Menu
+
+	v	Mark and verify the critical parameters (a,d,s)
+
+	s	Mark and verify the standard deviation of the sky
+	l	Mark and verify the minimum good data value
+	u	Mark and verify the maximum good data value
+
+	a	Mark and verify the inner radius of the sky annulus
+	d	Mark and verify the width of the sky annulus
+	g	Mark and verify the region growing radius
diff --git a/noao/digiphot/apphot/fitsky/mkpkg b/noao/digiphot/apphot/fitsky/mkpkg
new file mode 100644
index 00000000..a72edc57
--- /dev/null
+++ b/noao/digiphot/apphot/fitsky/mkpkg
@@ -0,0 +1,59 @@
+# FITSKY Task Tools
+
+$checkout libpkg.a ".."
+$update libpkg.a
+$checkin libpkg.a ".."
+$exit
+
+libpkg.a:
+	apavsky.x	../lib/display.h	../lib/fitsky.h
+	apbsky.x	<fset.h>		../lib/apphot.h         \
+			../lib/display.h
+	apcentroid.x	<mach.h>		../lib/fitsky.h
+	apcrosscor.x	<mach.h>		../lib/fitsky.h
+	apfitsky.x	../lib/apphotdef.h	../lib/noisedef.h	\
+			../lib/fitskydef.h	../lib/fitsky.h         \
+			../lib/apphot.h
+	apgauss.x	<mach.h>		../lib/fitsky.h         \
+			<math/nlfit.h>
+	apgrowhist.x
+	apgspars.x	../lib/display.h	../lib/fitsky.h         \
+			../lib/noise.h
+	aphgmsub.x
+	aphistplot.x	<gset.h>		<pkg/gtools.h>		\
+			../lib/fitsky.h
+	aplgsky.x	<mach.h>		../lib/fitsky.h
+	apmean.x	<mach.h>		../lib/fitsky.h
+	apmedian.x	<mach.h>		../lib/fitsky.h
+	apmode.x	<mach.h>		../lib/fitsky.h
+	appsky.x	../lib/fitsky.h		../lib/apphot.h
+	apradplot.x	../lib/fitsky.h
+	apreadsky.x
+	aprefitsky.x	../lib/apphotdef.h	../lib/noisedef.h	\
+			../lib/fitskydef.h	../lib/fitsky.h         \
+			../lib/apphot.h
+	aprgrow.x
+	apsconfirm.x	../lib/apphot.h		../lib/noise.h          \
+			../lib/fitsky.h
+	apserrors.x	../lib/fitsky.h
+	apsfree.x	../lib/apphotdef.h	../lib/fitskydef.h
+	apsinit.x	../lib/apphotdef.h	../lib/fitskydef.h      \
+			../lib/fitsky.h
+	apsky.x		<ctype.h>		<gset.h>		\
+			../lib/apphot.h		../lib/display.h        \
+			../lib/fitsky.h         <imhdr.h>
+	apskybuf.x	<imhdr.h>		<math.h>                \
+			../lib/apphotdef.h	../lib/fitskydef.h	\
+			../lib/fitsky.h         <mach.h>
+	apskycolon.x	../lib/apphot.h		../lib/fitsky.h         \
+			../lib/display.h	../lib/noise.h
+	apsradsetup.x	../lib/display.h	../lib/fitsky.h
+	appspars.x	../lib/display.h
+	apsplot.x	<pkg/gtools.h>		<gset.h>		\
+			../lib/apphot.h		../lib/noise.h          \
+			../lib/fitsky.h		../lib/fitskydef.h	\
+			../lib/apphotdef.h
+	apsshow.x	../lib/display.h	../lib/fitsky.h
+	t_fitsky.x	<fset.h>		<gset.h>		\
+			../lib/apphot.h		<imhdr.h>
+	;
diff --git a/noao/digiphot/apphot/fitsky/t_fitsky.x b/noao/digiphot/apphot/fitsky/t_fitsky.x
new file mode 100644
index 00000000..c9fb7db8
--- /dev/null
+++ b/noao/digiphot/apphot/fitsky/t_fitsky.x
@@ -0,0 +1,303 @@
+include <gset.h>
+include <fset.h>
+include <imhdr.h>
+include "../lib/apphot.h"
+
+# T_FITSKY -- Procedure to fit sky values in a an annular region around
+# a list of objects.
+
+procedure t_fitsky ()
+
+pointer image		# pointer to the name of the image
+pointer	output		# pointer to output file name
+pointer	coords		# coordinate file
+pointer	plotfile	# pointer to file of graphics metacode
+pointer graphics	# pointer to graphics display device
+pointer	display		# pointer to display device
+int	interactive	# mode of use
+int	cache		# cache the image pixels in memory
+int	verify		# verify critical parameters
+int	update		# update the critical parameter
+int	verbose		# verbose mode
+
+pointer	sp, outfname, cname, ap, im, mgd, gd, id, str
+int	sid, lid, limlist, lclist, lolist, out, cl, pfd, root, stat, memstat
+int	imlist, clist, olist, wcs, req_size, old_size, buf_size
+
+pointer	immap(), gopen()
+int	imtlen(), imtgetim(), clplen(), clgfil(), btoi(), fnldir(), strncmp()
+int	strlen(), apsky(), imtopenp(), clpopnu(), open(), clgwrd(), ap_memstat()
+int	sizeof()
+bool	clgetb(), streq()
+errchk	gopen
+
+begin
+	# Allocate working space.
+	call smark (sp)
+	call salloc (image, SZ_FNAME, TY_CHAR)
+	call salloc (output, SZ_FNAME, TY_CHAR)
+	call salloc (coords, SZ_FNAME, TY_CHAR)
+	call salloc (plotfile, SZ_FNAME, TY_CHAR)
+	call salloc (graphics, SZ_FNAME, TY_CHAR)
+	call salloc (display, SZ_FNAME, TY_CHAR)
+	call salloc (outfname, SZ_FNAME, TY_CHAR)
+	call salloc (cname, SZ_FNAME, TY_CHAR)
+	call salloc (str, SZ_LINE, TY_CHAR)
+
+	# Set the standard output to flush on a newline.
+	call fseti (STDOUT, F_FLUSHNL, YES)
+
+	# Get input and output file names.
+	imlist = imtopenp ("image")
+	limlist = imtlen (imlist)
+	clist = clpopnu ("coords")
+	lclist = clplen (clist)
+	olist = clpopnu ("output")
+	lolist = clplen (olist)
+
+	# Check that image and coordinate list lengths match.
+	if (limlist < 1 || (lclist > 1 && lclist != limlist)) {
+	    call imtclose (imlist)
+	    call clpcls (clist)
+	    call clpcls (olist)
+	    call error (0, "Imcompatable image and coordinate list lengths")
+	}
+
+	# Check that image and output list lengths match.
+	if (lolist > 1 && lolist != limlist) {
+	    call imtclose (imlist)
+	    call clpcls (clist)
+	    call clpcls (olist)
+	    call error (0, "Imcompatible image and output list lengths")
+	}
+
+	call clgstr ("icommands.p_filename", Memc[cname], SZ_FNAME)
+	if (Memc[cname] != EOS)
+	    interactive = NO
+	#else if (lclist == 0)
+	    #interactive = YES
+	else
+	    interactive = btoi (clgetb ("interactive"))
+	cache = btoi (clgetb("cache"))
+	verify = btoi (clgetb ("verify"))
+	update = btoi (clgetb ("update"))
+	verbose = btoi (clgetb ("verbose"))
+
+	# Get the parameters.
+	call ap_sgpars (ap)
+	if (verify == YES && interactive == NO) {
+	    call ap_sconfirm (ap, NULL, 1)
+	    if (update == YES)
+		call ap_pspars (ap)
+	}
+
+        # Get the wcs information.
+        wcs = clgwrd ("wcsin", Memc[str], SZ_LINE, WCSINSTR)
+        if (wcs <= 0) {
+	    call eprintf (
+	        "Warning: Setting the input coordinate system to logical\n")
+            wcs = WCS_LOGICAL
+	}
+        call apseti (ap, WCSIN, wcs)
+        wcs = clgwrd ("wcsout", Memc[str], SZ_LINE, WCSOUTSTR)
+        if (wcs <= 0) {
+	    call eprintf (
+	        "Warning: Setting the output coordinate system to logical\n")
+            wcs = WCS_LOGICAL
+	}
+        call apseti (ap, WCSOUT, wcs)
+
+	# Get the graphics and display devices.
+	call clgstr ("graphics", Memc[graphics], SZ_FNAME)
+	call clgstr ("display", Memc[display], SZ_FNAME)
+
+	# Open plot files.
+	if (interactive == YES) {
+	    if (Memc[graphics] == EOS)
+	        gd = NULL
+	    else {
+                iferr {
+	            gd = gopen (Memc[graphics], APPEND+AW_DEFER, STDGRAPH)
+	        } then {
+	            call eprintf (
+		        "Warning: Error opening graphics device.\n")
+	            gd = NULL
+	        }
+	    }
+	    if (Memc[display] == EOS)
+	        id = NULL
+	    else if (streq (Memc[graphics], Memc[display]))
+	        id = gd
+	    else {
+	        iferr {
+	            id = gopen (Memc[display], APPEND, STDIMAGE)
+	        } then {
+		    call eprintf (
+		"Warning: Graphics overlay not available for display device.\n")
+		    id = NULL
+	        }
+	    }
+	} else {
+	    gd = NULL
+	    id = NULL
+	}
+
+	# Open the plot metacode file.
+	call clgstr ("plotfile", Memc[plotfile], SZ_FNAME)
+	if (Memc[plotfile] == EOS)
+	    pfd = NULL
+	else
+	    pfd = open (Memc[plotfile], APPEND, BINARY_FILE)
+	if (pfd != NULL)
+	    mgd = gopen (Memc[graphics], NEW_FILE, pfd)
+	else
+	    mgd = NULL
+
+	# Begin looping over image list.
+	sid = 1
+	while (imtgetim (imlist, Memc[image], SZ_FNAME) != EOF) {
+
+	    # Open image.
+ 	    im = immap (Memc[image], READ_ONLY, 0)
+	    call apimkeys (ap, im, Memc[image])
+
+	    # Set the image display viewport.
+	    if ((id != NULL) && (id != gd))
+		call ap_gswv (id, Memc[image], im, 4)
+
+	    # Cache the input image pixels.
+            req_size = MEMFUDGE * IM_LEN(im,1) * IM_LEN(im,2) *
+                sizeof (IM_PIXTYPE(im))
+            memstat = ap_memstat (cache, req_size, old_size)
+            if (memstat == YES)
+                call ap_pcache (im, INDEFI, buf_size)
+
+	    # Open the coordinate file, where coords is assumed to be a simple
+	    # text file in which the x and y positions are in columns 1 and 2
+	    # respectively and all remaining fields are ignored.
+
+	    if (lclist <= 0) {
+		cl = NULL
+		call strcpy ("", Memc[outfname], SZ_FNAME)
+	    } else {
+		stat = clgfil (clist, Memc[coords], SZ_FNAME)
+		root = fnldir (Memc[coords], Memc[outfname], SZ_FNAME)
+		if (strncmp ("default", Memc[coords+root], 7) == 0 || root ==
+		    strlen (Memc[coords])) {
+		    call ap_inname (Memc[image], Memc[outfname], "coo",
+		        Memc[outfname], SZ_FNAME)
+		    lclist = limlist
+	            cl = open (Memc[outfname], READ_ONLY, TEXT_FILE)
+		} else if (stat != EOF) {
+		    call strcpy (Memc[coords], Memc[outfname], SZ_FNAME)
+	            cl = open (Memc[outfname], READ_ONLY, TEXT_FILE)
+		} else {
+		    call apstats (ap, CLNAME, Memc[outfname], SZ_FNAME)
+		    call seek (cl, BOF)
+		}
+	    }
+	    call apsets (ap, CLNAME, Memc[outfname])
+	    call apfroot (Memc[outfname], Memc[str], SZ_LINE)
+	    call apsets (ap, CLROOT, Memc[str])
+
+	    # Open the output text file, if output is "default", dir$default
+	    # or a directory specification then the extension "sky" is added
+	    # to the image name and a suitable version number is appended to
+	    # the output name. If the output string is null to output file
+	    # is created.
+
+	    if (lolist == 0) {
+		out = NULL
+		call strcpy ("", Memc[outfname], SZ_FNAME)
+	    } else {
+	        stat = clgfil (olist, Memc[output], SZ_FNAME)
+		root = fnldir (Memc[output], Memc[outfname], SZ_FNAME)
+		if (strncmp ("default", Memc[output+root], 7) == 0 || root ==
+		    strlen (Memc[output])) {
+		    call apoutname (Memc[image], Memc[outfname], "sky",
+		        Memc[outfname], SZ_FNAME)
+		    out = open (Memc[outfname], NEW_FILE, TEXT_FILE)
+		    lolist = limlist
+		} else if (stat != EOF) {
+		    call strcpy (Memc[output], Memc[outfname], SZ_FNAME)
+		    out = open (Memc[outfname], NEW_FILE, TEXT_FILE)
+		} else
+		    call apstats (ap, OUTNAME, Memc[outfname], SZ_FNAME)
+	    }
+	    call apsets (ap, OUTNAME, Memc[outfname])
+
+	    # Fit the sky
+	    if (interactive == NO) {
+	        if (Memc[cname] != EOS)
+		    stat =  apsky (ap, im, cl, NULL, NULL, mgd, NULL, out,
+		        sid, NO, cache)
+	        else if (cl != NULL) {
+		    lid = 1
+	            call apbsky (ap, im, cl, NULL, out, sid, lid, gd, mgd, id,
+		        verbose)
+		    stat = NO
+		} else
+		    stat = NO
+	    } else
+		stat = apsky (ap, im, cl, NULL, gd, mgd, id, out, sid, YES,
+		    cache)
+
+	    # Cleanup.
+	    call imunmap (im)
+	    if (cl != NULL) {
+		if (lclist > 1)
+		    call close (cl)
+	    }
+	    if (out != NULL && lolist != 1) {
+		call close (out)
+		if (sid <= 1) {
+		    call apstats (ap, OUTNAME, Memc[outfname], SZ_FNAME)
+		    call delete (Memc[outfname])
+		}
+		sid = 1
+	    }
+
+	    # Uncache memory.
+	    call fixmem (old_size)
+
+	    if (stat == YES)
+		break
+	}
+
+	# If only one coordinate file for a list of images close.
+	if (cl != NULL && lclist == 1)
+	    call close (cl)
+
+	# If only one output file for a list of images close.
+	if (out != NULL && lolist == 1) {
+	    call close (out)
+	    if (sid <= 1) {
+		call apstats (ap, OUTNAME, Memc[outfname], SZ_FNAME)
+		call delete (Memc[outfname])
+	    }
+	}
+
+	# Close up plot files.
+	if (id == gd && id != NULL) {
+	    call gclose (id)
+	} else {
+	    if (gd != NULL)
+                call gclose (gd)
+	    if (id != NULL)
+	        call gclose (id)
+	}
+	if (mgd != NULL)
+	    call gclose (mgd)
+	if (pfd != NULL)
+	    call close (pfd)
+
+	# Free sky fitting structure
+	call apsfree (ap)
+
+	# Close up lists.
+	call imtclose (imlist)
+	call clpcls (clist)
+	call clpcls (olist)
+
+	call sfree (sp)
+end
diff --git a/noao/digiphot/apphot/fitskypars.par b/noao/digiphot/apphot/fitskypars.par
new file mode 100644
index 00000000..2a90cf33
--- /dev/null
+++ b/noao/digiphot/apphot/fitskypars.par
@@ -0,0 +1,17 @@
+# SKY FITTING PARAMETERS
+
+salgorithm,s,h,"centroid","|median|mode|centroid|gauss|crosscor|ofilter|histplot|radplot|constant|file|mean|",,Sky fitting algorithm
+annulus,r,h,10.0,,,Inner radius of sky annulus in scale units
+dannulus,r,h,10.0,,,Width of sky annulus in scale units
+skyvalue,r,h,0.0,,,User sky value
+smaxiter,i,h,10,,,Maximum number of sky fitting iterations
+sloclip,r,h,0.0,,,Lower clipping factor in percent
+shiclip,r,h,0.0,,,Upper clipping factor in percent
+snreject,i,h,50,,,Maximum number of sky fitting rejection iterations
+sloreject,r,h,3.0,,,Lower K-sigma rejection limit in sky sigma
+shireject,r,h,3.0,,,Upper K-sigma rejection limit in sky sigma
+khist,r,h,3.0,,,Half width of histogram in sky sigma
+binsize,r,h,0.10,,,Binsize of histogram in sky sigma
+smooth,b,h,no,,,Boxcar smooth the histogram
+rgrow,r,h,0.0,,,Region growing radius in scale units
+mksky,b,h,no,,,Mark sky annuli on the display
diff --git a/noao/digiphot/apphot/lib/apphot.h b/noao/digiphot/apphot/lib/apphot.h
new file mode 100644
index 00000000..b9c7fb33
--- /dev/null
+++ b/noao/digiphot/apphot/lib/apphot.h
@@ -0,0 +1,110 @@
+# APPHOT header file
+
+# APPHOT parameters (# 1 - 100)
+
+define	IMNAME		1	# Image name
+define	IMROOT		2	# Image name
+define	CLNAME		3	# Coordinates file name
+define	CLROOT		4	# Coordinates file name
+define	PLOTFILE	5	# Name of the plotfile
+define	OUTNAME		6	# Output file name
+
+define	WCSIN		7	# Input WCS
+define	WCSOUT		8	# Input WCS
+define	MW		9	# MWCS descriptor
+define	CTIN		10	# Input WCS transformation
+define	CTOUT		11	# Output WCS transformation
+
+define	SCALE		12	# Scale in pixels / unit
+define	FWHMPSF		13	# Full width half maximum of the PSF
+define	POSITIVE	14	# Emission or absorption feature
+define	DATAMIN		15	# Minimum good data value
+define	DATAMAX		16	# Maximum good data value
+
+define	ITIME		17	# Exposure time
+define	AIRMASS		18	# Airmass keyword
+define	FILTER		19	# Filter keyword
+define	OBSTIME		20	# Time of observation keyword
+
+define	XAIRMASS	21	# Airmass value
+define	FILTERID	22	# Filter id
+define	OTIME		23	# Time stamp
+define	EXPOSURE	24	# Exposure time keyword
+
+define	WX		25	# Previous X cursor position
+define	WY		26	# Previous Y cursor position
+define	CWX		27	# Current X cursor position
+define	CWY		28	# Current Y cursor position
+
+# Define the WCS types
+
+define	WCSINSTR		"|logical|tv|physical|world|"
+define	WCSOUTSTR		"|logical|tv|physical|"
+define	WCS_LOGICAL		1
+define	WCS_TV			2
+define	WCS_PHYSICAL		3
+define	WCS_WORLD		4
+
+# define APPHOT keywords
+
+define	KY_FWHMPSF	"fwhmpsf"
+define	KY_IMNAME	"image"
+define	KY_POSITIVE	"emission"
+define	KY_ITIME	"itime"
+define	KY_EXPOSURE	"exposure"
+define	KY_DATAMIN	"datamin"
+define	KY_DATAMAX	"datamax"
+define	KY_OUTNAME	"output"
+define	KY_CLNAME	"coords"
+define	KY_SCALE	"scale"
+define	KY_AIRMASS	"airmass"
+define	KY_XAIRMASS	"xairmass"
+define	KY_FILTER	"filter"
+define	KY_FILTERID	"ifilter"
+define	KY_OBSTIME	"obstime"
+define	KY_OTIME	"otime"
+
+# define APPHOT units strings
+
+define	UN_ASCALEUNIT	"scaleunit"
+define	UN_ASWITCH	"switch"
+define	UN_ACOUNTS	"counts"
+define	UN_AUNITS	"units"
+define	UN_ATIMEUNIT	"timeunit"
+define	UN_AKEYWORD	"keyword"
+define	UN_ANAME	"name"
+define	UN_ANUMBER	"number"
+
+# APPHOT string commands
+
+define	APCMDS	"|fwhmpsf|emission|exposure|itime|datamin|datamax|image|coords|output|scale|airmass|xairmass|filter|ifilter|obstime|otime|"
+
+define	APCMD_FWHMPSF	1
+define	APCMD_EMISSION	2
+define	APCMD_EXPOSURE	3
+define	APCMD_ITIME	4
+define	APCMD_DATAMIN	5
+define	APCMD_DATAMAX	6
+define	APCMD_IMAGE	7
+define	APCMD_COORDS	8
+define	APCMD_OUTPUT	9
+define	APCMD_SCALE	10
+define	APCMD_AIRMASS	11
+define	APCMD_XAIRMASS	12
+define	APCMD_FILTER	13
+define	APCMD_FILTERID	14
+define	APCMD_OBSTIME	15
+define	APCMD_OTIME	16
+
+
+# Define the memory cacheing fudge factor
+
+define	MEMFUDGE	1.05
+
+# Miscellaneous commands
+
+define	MISC	"|show|radplots|"
+define	MISC1	"|show|"
+
+define	ACMD_SHOW	1
+define	ACMD_RADPLOTS	2
diff --git a/noao/digiphot/apphot/lib/apphotdef.h b/noao/digiphot/apphot/lib/apphotdef.h
new file mode 100644
index 00000000..a63b6dbd
--- /dev/null
+++ b/noao/digiphot/apphot/lib/apphotdef.h
@@ -0,0 +1,80 @@
+# APPHOT Structure
+
+define	LEN_APSTRUCT	(36 + 12 * SZ_FNAME + 12)
+
+# apphot definitions
+
+define	AP_VERSION	Memi[$1]	# Package version number
+define	AP_CWX		Memr[P2R($1+1)]	# Current x cursor coordinate
+define	AP_CWY		Memr[P2R($1+2)]	# Current y cursor coordinate
+define	AP_WX		Memr[P2R($1+3)]	# Previous x cursor coordinate
+define	AP_WY		Memr[P2R($1+4)]	# Previous y cursor coordinate
+define	AP_FWHMPSF	Memr[P2R($1+5)]	# FWHM of the PSF
+define	AP_SCALE	Memr[P2R($1+6)]	# Scale in pixels / unit (internal)
+define	AP_POSITIVE	Memi[$1+7]	# Emission feature ?
+define	AP_DATAMIN	Memr[P2R($1+8)]	# Mininum good data value
+define	AP_DATAMAX	Memr[P2R($1+9)]	# Maximum good data value
+define	AP_ITIME	Memr[P2R($1+10)] # Exposure time
+define	AP_XAIRMASS	Memr[P2R($1+11)] # Air mass
+
+# pointer to the apphot strucutures
+
+define	AP_NOISE	Memi[$1+12]	# Pointer to noise structure
+define	AP_PCENTER	Memi[$1+13]	# Pointer to center structure
+define	AP_PSKY		Memi[$1+14]	# Pointer to sky structure
+define	AP_PPSF		Memi[$1+15]	# Pointer to psf structure
+define  AP_PPHOT        Memi[$1+16]	# Pointer to phot structure
+define	AP_PDISPLAY	Memi[$1+17]	# Pointer to display structure
+define	AP_POLY		Memi[$1+18]	# Pointer to polyphot structure
+define	AP_RPROF	Memi[$1+19]	# Pointer to radprof strucuture
+define	AP_PFIND	Memi[$1+20]	# Pointer to the find structure
+
+# pointer to sequential access buffer (not used currently)
+
+define	AP_SEQUENTIAL	Memi[$1+21]	# Sequential or random access
+define	AP_IMBUF	Memi[$1+22]	# Pointer to internal buffer
+define	AP_HWIDTH	Memi[$1+23]	# Half-width of buffer in image lines
+define	AP_IMX1		Memi[$1+24]	# Lower column limit of buffer
+define	AP_IMX2		Memi[$1+25]	# Upper column limit of buffer
+define	AP_IMY1		Memi[$1+26]	# Lower line limit of buffer
+define	AP_IMY2		Memi[$1+27]	# Upper line limit of buffer
+
+# pointer to the wcs info
+
+
+define	AP_WCSIN	Memi[$1+28]	# the input wcs
+define	AP_WCSOUT	Memi[$1+29]	# the output wcs
+define	AP_MW		Memi[$1+30]	# the mwcs pointer
+define	AP_CTIN	        Memi[$1+31]	# the input transformation pointer
+define	AP_CTOUT        Memi[$1+32]	# the output transformation pointer
+
+# image, file and keyword names
+
+define  AP_IMNAME	Memc[P2C($1+36)]                # IRAF image name
+define  AP_IMROOT	Memc[P2C($1+36+SZ_FNAME+1)]     # IRAF image root name
+define	AP_CLNAME	Memc[P2C($1+36+2*SZ_FNAME+2)]   # Coordinate list
+define	AP_CLROOT	Memc[P2C($1+36+3*SZ_FNAME+3)]   # Coordinate list root
+define	AP_PLOTFILE	Memc[P2C($1+36+4*SZ_FNAME+4)]	# Plotfile
+define	AP_OUTNAME	Memc[P2C($1+36+5*SZ_FNAME+5)]	# Output
+define	AP_EXPOSURE	Memc[P2C($1+36+6*SZ_FNAME+6)]	# Exposure keyword
+define	AP_AIRMASS	Memc[P2C($1+36+7*SZ_FNAME+7)]	# Airmass keyword
+define	AP_FILTER	Memc[P2C($1+36+8*SZ_FNAME+8)]	# Filter keyword
+define	AP_FILTERID	Memc[P2C($1+36+9*SZ_FNAME+9)]	# Filter id
+define	AP_OBSTIME	Memc[P2C($1+36+10*SZ_FNAME+10)]	# Obstime keyword
+define	AP_OTIME	Memc[P2C($1+36+11*SZ_FNAME+11)]	# Time of observation
+
+# default definitions
+
+define	DEF_SCALE	1.0000
+define	DEF_POSITIVE	YES
+define	DEF_DATAMIN	INDEFR
+define	DEF_DATAMAX	INDEFR
+
+define	DEF_EXPOSURE	""
+define	DEF_AIRMASS	""
+define	DEF_FILTER	""
+define	DEF_OBSTIME	""
+define	DEF_ITIME	INDEFR
+define	DEF_XAIRMASS	INDEFR
+define	DEF_FILTERID	"INDEF"
+define	DEF_OTIME	"INDEF"
diff --git a/noao/digiphot/apphot/lib/center.h b/noao/digiphot/apphot/lib/center.h
new file mode 100644
index 00000000..ecf672f3
--- /dev/null
+++ b/noao/digiphot/apphot/lib/center.h
@@ -0,0 +1,102 @@
+# CENTER defintions
+
+# centering algorithms
+
+define	AP_CENTROID1D	1	# 1D centroiding
+define	AP_GAUSS1D	2	# 1D Gaussian
+define	AP_NONE		3	# No centering
+define	AP_OFILT1D	4	# 1-D optimal filtering
+
+# centering errors (# 101 - 200)
+
+define	AP_OK			0	# No error
+define	AP_CTR_NOAREA		101	# No pixels for centering
+define	AP_CTR_OUTOFBOUNDS	102	# Centering aperture extends oob
+define	AP_CTR_LOWSNRATIO	103	# S/N ratio too low for centering
+define	AP_CTR_NTOO_SMALL	104	# Too few histogram bins
+define	AP_CTR_SINGULAR		105	# Fit is singular
+define	AP_CTR_NOCONVERGE	106	# Solution does not converge
+define	AP_CTR_BADSHIFT		107	# Max shift parameter exceeded
+define	AP_CTR_BADDATA		108	# Bad data in centering subraster
+
+# centering parameters (# 101 - 200)
+
+define	CAPERT		101
+define	CENTERFUNCTION	102
+define	MINSNRATIO	103
+define	MAXSHIFT	104
+define	CLEAN		105
+define	RCLEAN		106
+define	RCLIP		107
+define	SIGMACLEAN	108
+define	OXINIT		109
+define	OYINIT		110
+define	XCENTER		111
+define	YCENTER		112
+define	OXCENTER	113
+define	OYCENTER	114
+define	XERR		115
+define	YERR		116
+define	CMAXITER	117
+define	CXCUR		118
+define	CYCUR		119
+define	XSHIFT		120
+define	YSHIFT		121
+define	OXSHIFT		122
+define	OYSHIFT		123
+define	CSTRING		124
+define	CDATALIMIT	125
+define	CTHRESHOLD	126
+
+# center keywords
+
+define	KY_CAPERT	"cboxwidth"
+define	KY_CSTRING	"calgorithm"
+define	KY_MINSNRATIO	"minsnratio"
+define	KY_MAXSHIFT	"maxshift"
+define	KY_CLEAN	"clean"
+define	KY_RCLEAN	"rclean"
+define	KY_RCLIP	"rclip"
+define	KY_SIGMACLEAN	"kclean"
+define	KY_CMAXITER	"cmaxiter"
+define	KY_CTHRESHOLD	"cthreshold"
+
+# center unit strings
+
+#define	UN_CAPERT	"scaleunit"
+#define	UN_CSTRING	"algorithm"
+#define	UN_MINSNRATIO	"number"
+#define	UN_MAXSHIFT	"scaleunit"
+#define	UN_CLEAN	"switch"
+#define	UN_RCLEAN	"scaleunit"
+#define	UN_RCLIP	"scaleunit"
+#define	UN_SIGMACLEAN	"sigma"
+#define	UN_CMAXITER	"number"
+#define	UN_CTHRESHOLD	"sigma"
+
+define	UN_CSCALEUNIT	"scaleunit"
+define	UN_CNUMBER	"number"
+define	UN_CSIGMA	"sigma"
+define	UN_CSWITCH	"switch"
+define	UN_CALGORITHM	"algorithm"
+
+# center string commands
+
+define	CSHOWARGS	"|data|center|"
+define	CFUNCS		"|centroid|gauss|none|ofilter|"
+define	CCMDS		"|cboxwidth|calgorithm|maxshift|minsnratio|cmaxiter|clean|rclean|rclip|kclean|mkcenter|cthreshold|"
+
+define	CCMD_CBOXWIDTH		1
+define	CCMD_CALGORITHM		2
+define	CCMD_MAXSHIFT		3
+define	CCMD_MINSNRATIO		4
+define	CCMD_CMAXITER		5
+define	CCMD_CLEAN		6
+define	CCMD_RCLEAN		7
+define	CCMD_RCLIP		8
+define	CCMD_KCLEAN		9
+define	CCMD_MKCENTER		10
+define	CCMD_CTHRESHOLD		11
+
+define	CCMD_DATA		1
+define	CCMD_CENTER		2
diff --git a/noao/digiphot/apphot/lib/centerdef.h b/noao/digiphot/apphot/lib/centerdef.h
new file mode 100644
index 00000000..c9dcd6a4
--- /dev/null
+++ b/noao/digiphot/apphot/lib/centerdef.h
@@ -0,0 +1,60 @@
+# CENTER header file
+
+define	LEN_CENSTRUCT		(36 + SZ_FNAME + 1)
+
+# centering parameters
+
+define	AP_CENTERFUNCTION   Memi[$1]		# Centering algorithm
+define	AP_CAPERT	    Memr[P2R($1+1)]	# Centering box half-width
+define	AP_CTHRESHOLD	    Memr[P2R($1+2)]  	# Threshold above cdatalimit
+define	AP_MAXSHIFT	    Memr[P2R($1+3)]	# Maximum center shift
+define	AP_MINSNRATIO	    Memr[P2R($1+4)]	# Minimum s/n ratio 
+define	AP_CLEAN	    Memi[$1+5]		# Clean before centering
+define	AP_RCLEAN	    Memr[P2R($1+6)]	# Cleaning radius
+define  AP_RCLIP	    Memr[P2R($1+7)]	# Clipping radius
+define	AP_SIGMACLEAN	    Memr[P2R($1+8)]	# Sky sigma for cleaning
+define	AP_CMAXITER	    Memi[$1+9]		# Maximum number of iterations
+
+# centering buffers
+
+define	AP_CTRPIX	    Memi[$1+10]		# Pointer to pixels
+define	AP_XCTRPIX	    Memi[$1+11]		# Pointer to x coords (not used)
+define	AP_YCTRPIX	    Memi[$1+12]		# Pointer to y coords (not used)
+define	AP_NCTRPIX	    Memi[$1+13]		# Number of pixels (not used)
+define	AP_LENCTRBUF	    Memi[$1+14]		# Centering buffer sz (not used)
+define	AP_CXCUR	    Memr[P2R($1+15)]	# Centering buffer x center
+define	AP_CYCUR	    Memr[P2R($1+16)]	# Centering buffer y center
+define	AP_CXC		    Memr[P2R($1+17)]	# X center of subraster
+define	AP_CYC		    Memr[P2R($1+18)]	# Y center of subraster
+define	AP_CNX		    Memi[$1+19]		# Y dimension of subraster
+define	AP_CNY		    Memi[$1+20]		# Y dimension of subraster
+
+# center fitting output
+
+define	AP_OXINIT	    Memr[P2R($1+21)]	# initial output x center
+define	AP_OYINIT	    Memr[P2R($1+22)]	# initial output y center
+define	AP_XCENTER	    Memr[P2R($1+23)]	# computed x center
+define	AP_YCENTER	    Memr[P2R($1+24)]	# computed y center
+define	AP_OXCENTER	    Memr[P2R($1+25)]	# computed output x center
+define	AP_OYCENTER	    Memr[P2R($1+26)]	# computed output y center
+define	AP_XSHIFT	    Memr[P2R($1+27)]	# total x shift
+define	AP_YSHIFT	    Memr[P2R($1+28)]	# total y shift
+define	AP_OXSHIFT	    Memr[P2R($1+29)]	# total output x shift
+define	AP_OYSHIFT	    Memr[P2R($1+30)]	# total output y shift
+define	AP_XERR		    Memr[P2R($1+31)]	# x error
+define	AP_YERR		    Memr[P2R($1+32)]	# y error
+define	AP_CDATALIMIT	    Memr[P2R($1+33)]	# min (max) of subraster
+define	AP_CSTRING	    Memc[P2C($1+34)]# centering algorithm id
+
+# default setup values for centering parameters
+
+define	DEF_CENTERFUNCTION	AP_CENTROID1D
+define	DEF_CAPERT		2.5
+define	DEF_CTHRESHOLD		0.0
+define	DEF_MINSNRATIO		1.0
+define	DEF_CMAXITER		10
+define	DEF_MAXSHIFT		1.0
+define	DEF_CLEAN		NO
+define	DEF_RCLEAN		1.0
+define	DEF_RCLIP		2.0
+define	DEF_CLEANSIGMA		3.0
diff --git a/noao/digiphot/apphot/lib/display.h b/noao/digiphot/apphot/lib/display.h
new file mode 100644
index 00000000..ae8ff523
--- /dev/null
+++ b/noao/digiphot/apphot/lib/display.h
@@ -0,0 +1,21 @@
+# APPHOT display parameters
+
+# display parameters (# 501 - 600)
+
+define	MKSKY		501
+define	MKCENTER	502
+define	MKAPERT		503
+define	MKPOLYGON	504
+define	MKPSFBOX	505
+define	RADPLOTS	506
+define	MKDETECTIONS	507
+
+# display parameters
+
+define	KY_MKSKY		"mksky"
+define	KY_MKCENTER		"mkcenter"
+define	KY_MKAPERT		"mkapert"
+define	KY_MKPOLYGON		"mkpolygon"
+define	KY_MKPSFBOX		"mkbox"
+define	KY_RADPLOTS		"radplots"
+define	KY_MKDETECTIONS		"mkdetections"
diff --git a/noao/digiphot/apphot/lib/displaydef.h b/noao/digiphot/apphot/lib/displaydef.h
new file mode 100644
index 00000000..8add188d
--- /dev/null
+++ b/noao/digiphot/apphot/lib/displaydef.h
@@ -0,0 +1,23 @@
+# APPHOT display structure
+
+define	LEN_DISPLAYSTRUCT	10
+
+# display parameters
+
+define	AP_MKSKY		Memi[$1]	# Mark sky circles
+define	AP_MKCENTER		Memi[$1+1]	# Mark center circles
+define	AP_MKAPERT		Memi[$1+2]	# Mark aperture circles
+define	AP_MKPOLYGON		Memi[$1+3]	# Mark polygon
+define	AP_MKPSFBOX		Memi[$1+4]	# Mark psf fitting box
+define	AP_RADPLOTS		Memi[$1+5]	# Make radial plots
+define	AP_MKDETECTIONS		Memi[$1+6]	# Mark detected stars
+
+# default values for the display parameters
+
+define	DEF_MKSKY		NO
+define	DEF_MKCENTER		NO
+define	DEF_MKAPERT		NO
+define	DEF_MKPOLYGON		NO
+define	DEF_MKPSFBOX		NO
+define	DEF_RADPLOTS		NO
+define	DEF_MKDETECTIONS	NO
diff --git a/noao/digiphot/apphot/lib/find.h b/noao/digiphot/apphot/lib/find.h
new file mode 100644
index 00000000..b5e3760b
--- /dev/null
+++ b/noao/digiphot/apphot/lib/find.h
@@ -0,0 +1,75 @@
+# Find header file
+
+# find parameters (# 701 - 800)
+
+define	RATIO		701
+define	THETA		702
+define	NSIGMA		703
+define	SHARPLO		704
+define	SHARPHI		705
+define	ROUNDLO		706
+define	ROUNDHI		707
+define	THRESHOLD	708
+
+# find keyword units
+
+define	KY_RATIO	"ratio"
+define	KY_THETA	"theta"
+define	KY_NSIGMA	"nsigma"
+define	KY_SHARPLO	"sharplo"
+define	KY_SHARPHI	"sharphi"
+define	KY_ROUNDLO	"roundlo"
+define	KY_ROUNDHI	"roundhi"
+define	KY_THRESHOLD	"threshold"
+
+# find parameter units
+
+#define	UN_RATIO	"number"
+#define	UN_THETA	"degrees"
+#define	UN_NSIGMA	"sigma"
+#define	UN_SHARPLO	"number"
+#define	UN_SHARPHI	"number"
+#define	UN_ROUNDLO	"number"
+#define	UN_ROUNDHI	"number"
+#define	UN_THRESHOLD	"sigma"
+
+define	UN_FNUMBER	"number"
+define	UN_FSIGMA	"sigma"
+define	UN_FDEGREES	"degrees"
+
+# define daofind commands
+
+define FSHOWARGS	"|data|find|"
+define FCMDS  "|nsigma|ratio|sharplo|sharphi|roundlo|roundhi|mkdetections|\
+theta|threshold|"
+
+# define daofind command strings
+
+define	FCMD_NSIGMA		1
+define	FCMD_RATIO		2
+define	FCMD_SHARPLO		3
+define	FCMD_SHARPHI		4
+define	FCMD_ROUNDLO		5
+define	FCMD_ROUNDHI		6
+define	FCMD_MKDETECTIONS	7
+define	FCMD_THETA		8
+define	FCMD_THRESHOLD		9
+
+define	FCMD_DATA		1
+define	FCMD_FIND		2
+
+
+# define the gaussian sums structure
+
+define	LEN_GAUSS		10
+
+define	GAUSS_SUMG		1
+define	GAUSS_SUMGSQ		2
+define	GAUSS_PIXELS		3
+define	GAUSS_DENOM		4
+define	GAUSS_SGOP		5
+
+# miscellaneous
+
+define	FWHM_TO_SIGMA		0.42467
+define	RMIN			2.001
diff --git a/noao/digiphot/apphot/lib/finddef.h b/noao/digiphot/apphot/lib/finddef.h
new file mode 100644
index 00000000..4ea9e99d
--- /dev/null
+++ b/noao/digiphot/apphot/lib/finddef.h
@@ -0,0 +1,26 @@
+# FIND header file
+
+define	LEN_FIND		(10)
+
+# find model parameters
+
+define	AP_RATIO	Memr[P2R($1)]	# Gaussian axis ratio
+define	AP_THETA 	Memr[P2R($1+1)]	# Gaussian position angle
+define	AP_NSIGMA	Memr[P2R($1+2)]	# Size of convolution kernel
+define	AP_SHARPLO	Memr[P2R($1+3)]	# Lower sharpness bound
+define	AP_SHARPHI	Memr[P2R($1+4)]	# Upper sharpness bound
+define	AP_ROUNDLO	Memr[P2R($1+5)]	# Lower roundness bound
+define	AP_ROUNDHI	Memr[P2R($1+6)]	# Higher roundness bound
+define	AP_THRESHOLD	Memr[P2R($1+7)]	# Threshold in sigma for detection
+
+
+# noise model defaults
+
+define	DEF_RATIO		1.0
+define	DEF_THETA		0.0
+define	DEF_NSIGMA		1.5
+define	DEF_SHARPLO		0.2
+define	DEF_SHARPHI		1.0
+define	DEF_ROUNDLO		-1.0
+define	DEF_ROUNDHI		1.0
+define	DEF_THRESHOLD		0.0
diff --git a/noao/digiphot/apphot/lib/fitpsf.h b/noao/digiphot/apphot/lib/fitpsf.h
new file mode 100644
index 00000000..5aa5f04c
--- /dev/null
+++ b/noao/digiphot/apphot/lib/fitpsf.h
@@ -0,0 +1,72 @@
+# FITPSF header file
+
+# fitpsf functions
+
+define	AP_RADGAUSS		1	# Radial Gaussian
+define  AP_ELLGAUSS		2	# Elliptical Gaussian
+define	AP_MOMENTS		3	# Moment analysis
+
+# fitpsf errors (# 401 - 500)
+
+define	AP_OK			0	# no error
+define	AP_NOPSFAREA		401	# No pixels for PSF
+define	AP_PSF_OUTOFBOUNDS	402	# PSF aperture extends oob
+define	AP_NPSF_TOO_SMALL	403	# Too few PSF points
+define	AP_PSF_SINGULAR		404	# Fit is singular
+define	AP_PSF_NOCONVERGE	405	# Solution does not converge
+
+# fitpsf parameters (# 401 - 500)
+
+define	PSFUNCTION	401
+define	MAXNPARS	402
+define	PK2		403
+define	PMAXITER	404
+define	PSFAPERT	405
+define	NPARS		406
+define	PARS		407
+define	PERRS		408
+define	PNREJECT	409
+define	PFXCUR		410
+define	PFYCUR		411
+define	OPFXCUR		412
+define	OPFYCUR		413
+define	PSFSTRING	414
+
+# define fitpsf keywords
+
+define	KY_PSFUNCTION	"function"
+define	KY_PSFAPERT	"box"
+define	KY_PK2		"kreject"
+define	KY_PMAXITER	"maxiter"
+define	KY_PNREJECT	"nreject"
+define	KY_PSFSTRING	"function"
+
+# define fitpsf units
+
+#define	UN_PSFUNCTION	"model"
+#define	UN_PSFAPERT	"scaleunit"
+#define	UN_PK2		"sigma"
+#define	UN_PMAXITER	"number"
+#define	UN_PNREJECT	"number"
+#define	UN_PSFSTRING	"model"
+
+define	UN_PSFSCALEUNIT	"scaleunit"
+define	UN_PSFNUMBER	"number"
+define	UN_PSFMODEL	"model"
+define	UN_PSFSIGMA	"sigma"
+
+# fitpsf string constants
+
+define	PFSHOWARGS	"|data|fit|"
+define	PSFFUNCS	"|radgauss|elgauss|moments|"
+define	PSFCMDS		"|function|box|kreject|maxiter|nreject|mkbox|"
+
+define	PFCMD_DATA		1
+define	PFCMD_FIT		2
+
+define	PFCMD_FUNCTION		1
+define	PFCMD_BOX		2
+define	PFCMD_KREJECT		3
+define	PFCMD_MAXITER		4
+define	PFCMD_NREJECT		5
+define	PFCMD_MKBOX		6
diff --git a/noao/digiphot/apphot/lib/fitpsfdef.h b/noao/digiphot/apphot/lib/fitpsfdef.h
new file mode 100644
index 00000000..bbd88ad0
--- /dev/null
+++ b/noao/digiphot/apphot/lib/fitpsfdef.h
@@ -0,0 +1,43 @@
+# FITPSF header file
+
+define	LEN_PSFSTRUCT		(25 + SZ_FNAME + 1)
+
+# fitpsf parameters
+
+define	AP_PSFUNCTION	Memi[$1]	# PSF function
+define	AP_PSFNPARS	Memi[$1+1]	# Number of parameters
+define	AP_MAXNPARS	Memi[$1+2]	# Maximum number of parameters
+define	AP_PSFAPERT	Memr[P2R($1+3)]	# Half-width of fitting box
+define	AP_PMAXITER	Memi[$1+4]	# Maximum number of iterations
+define	AP_PK2		Memr[P2R($1+5)]	# Rejection limit in sigma
+define	AP_PNREJECT	Memi[$1+6]	# Maximum number of rejections
+
+# fitpsf buffers
+
+define	AP_PSFPIX	Memi[$1+7]	# Pointer to pixels
+define	AP_PSFXPIX	Memi[$1+8]	# X coordinates array (not used)
+define	AP_PSFYPIX	Memi[$1+9]	# Y coordinates array (not used)
+define	AP_NPSFPIX	Memi[$1+10]	# Number of pixels (not used)
+define	AP_LENPSFBUF	Memi[$1+11]	# Length of pixel buffer (not used)
+define	AP_PXC		Memr[P2R($1+12)]# X center of subraster
+define	AP_PYC		Memr[P2R($1+13)]# Y center of subraster
+define	AP_PNX		Memi[$1+14]	# X dimension of subraster
+define	AP_PNY		Memi[$1+15]	# Y dimension of subraster
+define	AP_PFXCUR	Memr[P2R($1+16)]# X initial position
+define	AP_PFYCUR	Memr[P2R($1+17)]# Y initial position
+define	AP_OPFXCUR	Memr[P2R($1+18)]# X initial position
+define	AP_OPFYCUR	Memr[P2R($1+19)]# Y initial position
+
+# fitpsf answers
+
+define	AP_PPARS	Memi[$1+20]	# fitted parameters
+define	AP_PPERRS	Memi[$1+21]	# errors in the parameters
+define	AP_PSFSTRING	Memc[P2C($1+22)] # functions string
+
+# default fitpsf parameters
+
+define	DEF_MAXNPARS		10
+define	DEF_PSFUNCTION		AP_RADGAUSS
+define	DEF_PMAXITER		50
+define	DEF_PK2			3.0
+define	DEF_PNREJECT		1
diff --git a/noao/digiphot/apphot/lib/fitsky.h b/noao/digiphot/apphot/lib/fitsky.h
new file mode 100644
index 00000000..b4cedaea
--- /dev/null
+++ b/noao/digiphot/apphot/lib/fitsky.h
@@ -0,0 +1,128 @@
+# FITSKY definitions
+
+# define the sky fitting algorithms
+
+define	AP_CONSTANT	1	# Use a constant sky
+define	AP_MODE		2	# Compute the mode of the sky pixels
+define	AP_CENTROID	3	# Compute the peak of the histogram
+define	AP_SKYFILE	4	# Get values from a file
+define	AP_HISTPLOT	5	# Mark the sky on a histogram plot
+define	AP_MEDIAN	6	# Take median of sky pixels
+define	AP_RADPLOT	7	# Mark sky on radial profile plot
+define	AP_GAUSS	8	# Non-linear fit to a Gaussian
+define	AP_OFILT	9	# Optimal filtering
+define	AP_CROSSCOR	10	# Cross correlation method
+define	AP_MEAN		11	# Compute the mean of the sky pixels
+
+# define sky fitting errors (# 201 - 300)
+
+define	AP_OK			0	# No error
+define	AP_NOSKYAREA		201	# Width of the annulus is <= 0.0 pixels
+define	AP_SKY_OUTOFBOUNDS	202	# Sky annulus out of bounds
+define	AP_NOHISTOGRAM		203	# Cannot make a histogram
+define	AP_FLAT_HIST		204	# Histogram is flat or concave
+define	AP_NSKY_TOO_SMALL	205	# Too few points for fit
+define	AP_SKY_SINGULAR		206	# Fit is singular
+define	AP_SKY_NOCONVERGE	207	# Solution does not converge
+define	AP_NOGRAPHICS		208	# NULL graphics pointer
+define	AP_NOSKYFILE		209	# NULL sky file descriptor
+define	AP_EOFSKYFILE		210	# End of sky file
+define	AP_BADSKYSCAN		211	# Incomplete scan of sky file
+define	AP_BADPARAMS		212	# Non-physical parameters
+
+# sky fitting parameters (# 201 - 300)
+
+define	SKYFUNCTION	201
+define	ANNULUS		202
+define	DANNULUS	203
+define	SKY_BACKGROUND	204
+define	K1		205
+define	BINSIZE		206
+define	SMOOTH		207
+define	SMAXITER	208
+define	SLOCLIP		209
+define	SHICLIP		210
+define	SNREJECT	211
+define	SLOREJECT	212
+define	SHIREJECT	213
+define	RGROW		214
+define	SKY_MODE	215
+define	SKY_SIGMA	216
+define	SKY_SKEW	217
+define	NSKY		218
+define	NSKY_REJECT	219
+define	SXCUR		220
+define	SYCUR		221
+define	OSXCUR		222
+define	OSYCUR		223
+define	SSTRING		224
+
+# define sky fitting keywords
+
+define	KY_SSTRING		"salgorithm"
+define	KY_ANNULUS		"annulus"
+define	KY_DANNULUS		"dannulus"
+define	KY_SKY_BACKGROUND	"skyvalue"
+define	KY_K1			"khist"
+define	KY_BINSIZE		"binsize"
+define	KY_SMOOTH		"smooth"
+define	KY_SMAXITER		"smaxiter"
+define	KY_SLOCLIP		"sloclip"
+define	KY_SHICLIP		"shiclip"
+define	KY_SNREJECT		"snreject"
+define	KY_SLOREJECT		"sloreject"
+define	KY_SHIREJECT		"shireject"
+define	KY_RGROW		"rgrow"
+
+# define sky fitting units strings
+
+#define	UN_SSTRING		"algorithm"
+#define	UN_ANNULUS		"scaleunit"
+#define	UN_DANNULUS		"scaleunit"
+#define	UN_SKY_BACKGROUND	"counts"
+#define	UN_K1			"sigma"
+#define	UN_BINSIZE		"sigma"
+#define	UN_SMOOTH		"switch"
+#define	UN_SMAXITER		"number"
+#define	UN_SLOCLIP		"percent"
+#define	UN_SHICLIP		"percent"
+#define	UN_SNREJECT		"number"
+#define	UN_SLOREJECT		"sigma"
+#define	UN_SHIREJECT		"sigma"
+#define	UN_RGROW		"scaleunit"
+
+define	UN_SALGORITHM		"algorithm"
+define	UN_SSCALEUNIT		"scaleunit"
+define	UN_SSIGMA		"sigma"
+define	UN_SNUMBER		"number"
+define	UN_SPERCENT		"percent"
+define	UN_SCOUNTS		"counts"
+define	UN_SSWITCH		"switch"
+
+# fitsky string definitions
+
+define	SSHOWARGS	"|data|sky|"
+define	SFUNCS		"|constant|mode|centroid|file|histplot|median|\
+radplot|gauss|ofilter|crosscor|mean|"
+define	SCMDS		"|annulus|dannulus|salgorithm|khist|sloreject|\
+shireject|smaxiter|binsize|smooth|rgrow|snreject|skyvalue|mksky|sloclip|\
+shiclip|"
+
+define	SCMD_ANNULUS		1
+define	SCMD_DANNULUS		2
+define	SCMD_SALGORITHM 	3
+define	SCMD_KHIST		4
+define	SCMD_SLOREJECT		5
+define	SCMD_SHIREJECT		6
+define	SCMD_SMAXITER		7
+define	SCMD_BINSIZE		8
+define	SCMD_SMOOTH		9
+define	SCMD_RGROW		10
+define	SCMD_SNREJECT		11
+define	SCMD_SKYVALUE 		12
+define	SCMD_MKSKY		13
+define	SCMD_SLOCLIP		14
+define	SCMD_SHICLIP		15
+
+define	SCMD_DATA		1
+define	SCMD_SKY		2
diff --git a/noao/digiphot/apphot/lib/fitskydef.h b/noao/digiphot/apphot/lib/fitskydef.h
new file mode 100644
index 00000000..f768851f
--- /dev/null
+++ b/noao/digiphot/apphot/lib/fitskydef.h
@@ -0,0 +1,65 @@
+# FITSKY structure
+
+define LEN_SKYSTRUCT		(36 + SZ_FNAME + 1)
+
+# sky fitting parameters
+
+define	AP_SKYFUNCTION	  Memi[$1]	   # sky fitting algorithm
+define	AP_ANNULUS	  Memr[P2R($1+1)]  # inner radius of annulus in scale 
+define	AP_DANNULUS	  Memr[P2R($1+2)]  # annulus width in scale
+define	AP_SKYBACKGROUND  Memr[P2R($1+3)]  # user defined sky value
+define	AP_K1		  Memr[P2R($1+4)]  # K-sigma histogram rejection
+define	AP_BINSIZE	  Memr[P2R($1+5)]  # histogram binsize in sky sigma
+define	AP_SMOOTH	  Memi[$1+6]	   # Smooth histogram ?
+define	AP_SMAXITER	  Memi[$1+7]	   # maximum number of iterations
+define	AP_SLOCLIP	  Memr[P2R($1+8)]  # lower clipping percentile
+define	AP_SHICLIP	  Memr[P2R($1+9)]  # lower clipping percentile
+define	AP_SNREJECT	  Memi[$1+10]	   # maximum number of rejection cycles
+define	AP_SLOREJECT	  Memr[P2R($1+11)] # lower K-sigma rejection for pixels
+define	AP_SHIREJECT	  Memr[P2R($1+12)] # higher K-sigma rejection for pixels
+define	AP_RGROW	  Memr[P2R($1+13)] # region growing radius in scale
+
+# sky buffer definitions
+
+define	AP_SKYPIX	Memi[$1+14]	   # pointer to sky pixels
+define	AP_INDEX	Memi[$1+15]	   # pointer to ordering array
+define	AP_COORDS	Memi[$1+16]	   # pointer to sky coordinates array
+define	AP_SWGT		Memi[$1+17]	   # pointer to sky weights
+define	AP_NSKYPIX	Memi[$1+18]	   # number of sky pixels
+define	AP_NBADSKYPIX	Memi[$1+19]	   # number of bad sky pixels
+define	AP_LENSKYBUF	Memi[$1+20]	   # length of sky buffers
+define	AP_SXCUR	Memr[P2R($1+21)]   # x center of sky annulus
+define	AP_SYCUR	Memr[P2R($1+22)]   # y center of sky annulus
+define	AP_SXC		Memr[P2R($1+23)]   # x center of sky subraster
+define	AP_SYC		Memr[P2R($1+24)]   # y center of sky subraster
+define	AP_SNX		Memi[$1+25]	   # x dimension of sky subraster
+define	AP_SNY		Memi[$1+26]	   # y dimension of sky subraster
+
+# fitsky output
+
+define	AP_OSXCUR	Memr[P2R($1+27)]   # x center of sky annulus
+define	AP_OSYCUR	Memr[P2R($1+28)]   # y center of sky annulus
+define	AP_SKY_MODE	Memr[P2R($1+29)]   # computed sky value
+define	AP_SKY_SIG	Memr[P2R($1+30)]   # computed sky sigma
+define	AP_SKY_SKEW	Memr[P2R($1+31)]   # computed sky skew
+define	AP_NSKY		Memi[$1+32]	   # number of sky pix
+define	AP_NSKY_REJECT	Memi[$1+33]	   # number of rejected sky pix
+
+define	AP_SSTRING	Memc[P2C($1+34)]   # salgorithm string
+
+# default setup values for sky fitting
+
+define	DEF_SKYFUNCTION		AP_MODE
+define	DEF_SKYVALUE		0.0
+define	DEF_ANNULUS		10.
+define	DEF_DANNULUS		10.
+define	DEF_SLOCLIP		0.0
+define	DEF_SHICLIP		0.0
+define	DEF_SNREJECT		50
+define	DEF_SLOREJECT		3.0
+define	DEF_SHIREJECT		3.0
+define	DEF_SMAXITER		10
+define	DEF_RGROW		0.0
+define	DEF_K1			3.0
+define	DEF_BINSIZE		0.10
+define	DEF_SMOOTH		NO
diff --git a/noao/digiphot/apphot/lib/noise.h b/noao/digiphot/apphot/lib/noise.h
new file mode 100644
index 00000000..32ef1ed1
--- /dev/null
+++ b/noao/digiphot/apphot/lib/noise.h
@@ -0,0 +1,54 @@
+# Noise model header file
+
+# noise parameters (# 601 - 700)
+
+define	SKYSIGMA	601
+define	EPADU		603
+define	NOISEFUNCTION	604
+define	GAIN		605
+define	NSTRING		606
+define	CCDREAD		607
+define	READNOISE	608
+
+# noise keywords
+
+define	KY_SKYSIGMA	"sigma"
+define	KY_EPADU	"epadu"
+define	KY_GAIN		"gain"
+define	KY_NSTRING	"noise"
+define	KY_CCDREAD	"ccdread"
+define	KY_READNOISE	"readnoise"
+
+# noise parameter units
+
+#define	UN_SKYSIGMA	"counts"
+#define	UN_EPADU	"e-/adu"
+#define	UN_GAIN		"keyword"
+#define	UN_NSTRING	"model"
+#define	UN_CCDREAD	"keyword"
+#define	UN_READNOISE	"e-"
+
+define	UN_NKEYWORD	"keyword"
+define	UN_NCOUNTS	"counts"
+define	UN_NELECTRONS	"e-"
+define	UN_NMODEL	"model"
+define	UN_NEPADU	"e-/adu"
+
+# noise functions
+
+define	AP_NCONSTANT	1
+define	AP_NPOISSON	2
+
+# noise model strings
+
+define	NCMDS "|noise|sigma|epadu|gain|ccdread|readnoise|"
+define	NFUNCS	"|constant|poisson|"
+
+# noise string cases
+
+define	NCMD_NOISE	1
+define	NCMD_SIGMA	2
+define	NCMD_EPADU	3
+define	NCMD_GAIN	4
+define	NCMD_CCDREAD	5
+define	NCMD_READNOISE	6
diff --git a/noao/digiphot/apphot/lib/noisedef.h b/noao/digiphot/apphot/lib/noisedef.h
new file mode 100644
index 00000000..3d67f5ec
--- /dev/null
+++ b/noao/digiphot/apphot/lib/noisedef.h
@@ -0,0 +1,21 @@
+# APPHOT header file
+
+define	LEN_APNOISE		(10 + 3 * SZ_FNAME + 3)
+
+# noise model parameters
+
+define	AP_NOISEFUNCTION	Memi[$1]	# Noise function
+define	AP_SKYSIGMA		Memr[P2R($1+2)]	# Sky sigma in counts
+define	AP_EPADU		Memr[P2R($1+3)]	# Photons per adu
+define	AP_READNOISE		Memr[P2R($1+4)]	# CCD readnoise in adu
+define	AP_GAIN			Memc[P2C($1+6)]	# Gain keyword
+define	AP_NSTRING		Memc[P2C($1+6+SZ_FNAME+1)] # Noise model
+define	AP_CCDREAD		Memc[P2C($1+6+2*SZ_FNAME+2)] # Readnoise
+
+# noise model defaults
+
+define	DEF_SKYSIGMA		INDEFR
+define	DEF_EPADU		1.0
+define	DEF_CCDREAD		""
+define	DEF_GAIN		""
+define	DEF_READNOISE		INDEFR
diff --git a/noao/digiphot/apphot/lib/phot.h b/noao/digiphot/apphot/lib/phot.h
new file mode 100644
index 00000000..ca9430f5
--- /dev/null
+++ b/noao/digiphot/apphot/lib/phot.h
@@ -0,0 +1,86 @@
+# APPHOT header file
+
+# phot errors (# 301 - 400)
+
+define	AP_OK			0	# no error
+define	AP_APERT_NOAPERT	301	# no aperture area
+define  AP_APERT_OUTOFBOUNDS	302	# 1 or more apertures out of bounds
+define	AP_APERT_NOSKYMODE	303	# INDEF valued sky
+define	AP_APERT_NEGMAG		304	# 0 or -ve magnitude
+define	AP_APERT_BADDATA	305	# bad pixels in aperture
+
+# phot parameters and answers (# 301 - 400)
+
+define	ZMAG		301
+define	APERTS		302
+define	NAPERTS		303
+define	MAGS		304
+define	MAGERRS		305
+define	PXCUR		306
+define	PYCUR		307
+define	OPXCUR		308
+define	OPYCUR		309
+define	AREAS		310
+define	SUMS		311
+define	PWEIGHTS	312
+define	PWSTRING	313
+define	APSTRING	314
+
+# define the phot keywords
+
+define	KY_ZMAG		"zmag"
+define	KY_PWSTRING	"weighting"
+define	KY_APERTS	"apertures"
+
+# define the phot units
+
+#define	UN_ZMAG		"zeropoint"
+#define	UN_PWSTRING	"model"
+#define	UN_APERTS	"scaleunit"
+
+define	UN_PZMAG	"zeropoint"
+define	UN_PMODEL	"model"
+define	UN_PSCALEUNIT	"scaleunit"
+
+# define the weighting functions
+
+define	AP_PWCONSTANT	1	# uniform weighting
+define	AP_PWCONE	2	# a cone of given fwhm is used
+define	AP_PWGAUSS	3	# a Gaussian of given fwhm is used
+
+# phot strings
+
+define	PCMDS		"|apertures|zmag|mkapert|weighting|"
+define	PSHOWARGS	"|center|sky|phot|data|"
+define	PWFUNCS		"|constant|cone|gauss|"
+define	QCMDS		"|show|cboxwidth|annulus|dannulus|apertures|zmag|epadu|exposure|radplots|image|output|coords|airmass|filter|obstime|"
+
+define	PCMD_APERTURES		1
+define	PCMD_ZMAG		2
+define	PCMD_MKAPERT		3
+define	PCMD_WEIGHTING		4
+
+define	PCMD_CENTER		1
+define	PCMD_SKY		2
+define	PCMD_PHOT		3
+define	PCMD_DATA		4
+
+define	QCMD_SHOW		1
+define	QCMD_CBOXWIDTH		2
+define	QCMD_ANNULUS		3
+define	QCMD_DANNULUS		4
+define	QCMD_APERTURES		5
+define	QCMD_ZMAG		6
+define	QCMD_EPADU		7
+define	QCMD_EXPOSURE		8
+define	QCMD_RADPLOTS		9
+define	QCMD_IMAGE		10
+define	QCMD_OUTPUT		11
+define	QCMD_COORDS		12
+define	QCMD_AIRMASS		13
+define	QCMD_FILTER		14
+define	QCMD_OBSTIME		15
+
+# miscellaneous
+
+define	MAX_NAPERTS	100
diff --git a/noao/digiphot/apphot/lib/photdef.h b/noao/digiphot/apphot/lib/photdef.h
new file mode 100644
index 00000000..3d02f11a
--- /dev/null
+++ b/noao/digiphot/apphot/lib/photdef.h
@@ -0,0 +1,43 @@
+# PHOT header file
+
+define	LEN_PHOTSTRUCT		(30 +  SZ_FNAME + SZ_LINE +  2)
+
+# photmetry aperture parameters
+
+define	AP_NAPERTS	Memi[$1]	 # Number of apertures
+define	AP_PXCUR	Memr[P2R($1+1)]	 # X aperture center
+define	AP_PYCUR	Memr[P2R($1+2)]	 # Y aperture center
+define	AP_NMAXAP	Memi[$1+3]	 # Maximum number of apertures
+define	AP_NMINAP	Memi[$1+4]	 # Minimum number of apertures
+define	AP_APERTS	Memi[$1+5]	 # Pointer to aperture array
+define	AP_APIX		Memi[$1+6]	 # Pointer to pixels
+define	AP_XAPIX	Memi[$1+7]	 # Pointer to x coords array (not used)
+define	AP_YAPIX	Memi[$1+8]	 # Pointer to y coords array (not used)
+define	AP_NAPIX	Memi[$1+9]	 # Number of pixels (not used)
+define	AP_LENABUF	Memi[$1+10]	 # Size of pixels buffer (not used)
+define	AP_AXC		Memr[P2R($1+11)] # X center of subraster
+define	AP_AYC		Memr[P2R($1+12)] # X center of subraster
+define	AP_ANX		Memi[$1+13]	 # X dimension of subraster
+define	AP_ANY		Memi[$1+14]	 # Y dimension of subraster
+define	AP_OPXCUR	Memr[P2R($1+15)] # X aperture center
+define	AP_OPYCUR	Memr[P2R($1+16)] # Y aperture center
+
+# photometry output
+
+define	AP_MAGS		Memi[$1+17]	 # Pointer to magnitude array
+define	AP_MAGERRS	Memi[$1+18]	 # Pointer to mag errors array
+define	AP_AREA		Memi[$1+19]	 # Pointer to areas array
+define	AP_SUMS		Memi[$1+20]	 # Pointer to aperture sums array
+
+# photometry parameters
+
+define	AP_ZMAG		Memr[P2R($1+21)] # Zero point of magnitude scale
+define	AP_PWEIGHTS	Memi[$1+22]	 # Weighting function for ophot
+define	AP_PWSTRING	Memc[P2C($1+24)] # Weights string
+define	AP_APSTRING	Memc[P2C($1+24+SZ_FNAME+1)] # Apertures string
+
+# phot default defintions
+
+define	DEF_ZMAG		25.0
+define	DEF_APERTS		"3.0"
+define	DEF_PWEIGHTS		AP_PWCONSTANT
diff --git a/noao/digiphot/apphot/lib/polyphot.h b/noao/digiphot/apphot/lib/polyphot.h
new file mode 100644
index 00000000..d41751c2
--- /dev/null
+++ b/noao/digiphot/apphot/lib/polyphot.h
@@ -0,0 +1,63 @@
+# POLYPHOT header file
+
+# polyphot error codes (# 801 - 900)
+
+define	PY_NOPOLYGON		801
+define	PY_OUTOFBOUNDS		802
+define	PY_NOPIX		803
+define	PY_NOSKYMODE		804
+define	PY_BADDATA		805
+define	PY_OK			0
+
+# polyphot parameters and answers (# 801 - 900)
+
+define	PYXMEAN			801
+define	PYYMEAN			802
+define	PYCX			803
+define	PYCY			804
+define	OPYXMEAN		805
+define	OPYYMEAN		806
+define	OPYCX			807
+define	OPYCY			808
+define	PYFLUX			809
+define	PYNPIX			810
+define	PYNVER			811
+define	PYMINRAD		812
+define	PYX			813
+define	PYY			814
+define	PYZMAG			815
+define	PYMAG			816
+define	PYMAGERR		817
+define	PYNAME			818
+define	PYROOT			819
+define	PYBADPIX		820
+
+# polyphot keywords
+
+define	KY_PYZMAG	"zmag"
+define	KY_PYNAME	"polyfile"
+
+# polyphot units
+
+define	UN_PYZMAG	"zeropoint"
+
+# miscellaneous polyphot definitions
+
+define	MAX_NVERTICES		900
+define	NEXT_POLYGON		0
+define	NEXT_OBJECT		1
+define	THIS_OBJECT		2
+
+# polyphot strings
+
+define	PYSHOWARGS	"|center|sky|phot|data|"
+define	PYCMDS		"|zmag|mkpolygon|polygons|"
+
+define	PLCMD_CENTER		1
+define	PLCMD_SKY		2
+define	PLCMD_PHOT		3
+define	PLCMD_DATA		4
+
+define	PLCMD_ZMAG		1
+define	PLCMD_MKPOLYGON		2
+define	PLCMD_POLYGONS		3
diff --git a/noao/digiphot/apphot/lib/polyphotdef.h b/noao/digiphot/apphot/lib/polyphotdef.h
new file mode 100644
index 00000000..4b354bfc
--- /dev/null
+++ b/noao/digiphot/apphot/lib/polyphotdef.h
@@ -0,0 +1,37 @@
+# POLYPHOT header file
+
+define	LEN_PYSTRUCT	(25 + 2 * SZ_FNAME + 2)
+
+# polyphot parameters
+
+define	AP_PYZMAG	Memr[P2R($1)]	# Zero point of mag scale
+
+# polygon parameters
+
+define	AP_PYXMEAN	Memr[P2R($1+1)]	# Original mean X of polygon
+define	AP_PYYMEAN	Memr[P2R($1+2)]	# Original mean Y of polygon
+define  AP_PYCX		Memr[P2R($1+3)]	# Current mean X of polygon
+define	AP_PYCY		Memr[P2R($1+4)]	# Current mean Y of polygon
+define	AP_PYX		Memr[P2R($1+5)]	# Previous mean X of polygon
+define	AP_PYY		Memr[P2R($1+6)]	# Previous mean Y of polygon
+define	AP_PYNVER	Memi[$1+7]	# Number of vertices
+define	AP_PYMINRAD	Memr[P2R($1+8)]	# Minimum sky fitting radius in scale
+define	AP_OPYXMEAN	Memr[P2R($1+9)]	# Original output mean X of polygon
+define	AP_OPYYMEAN	Memr[P2R($1+10)]# Original output mean Y of polygon
+define  AP_OPYCX	Memr[P2R($1+11)]# Current output mean X of polygon
+define	AP_OPYCY	Memr[P2R($1+12)]# Current output mean Y of polygon
+
+# polyphot answers
+
+define	AP_PYBADPIX	Memi[$1+13]	# Are there bad pixels ?
+define	AP_PYFLUX	Memd[P2D($1+14)]# Flux
+define	AP_PYNPIX	Memd[P2D($1+16)]# Polygon area
+define	AP_PYMAG	Memr[P2R($1+18)]# Magnitude
+define	AP_PYMAGERR	Memr[P2R($1+19)]# Magnitude error
+
+define	AP_PYNAME	Memc[P2C($1+21)]# Polygons file name
+define	AP_PYROOT	Memc[P2C($1+21+SZ_FNAME+1)]# Polygons file name
+
+# polyphot defaults
+
+define	DEF_PYZMAG	25.0
diff --git a/noao/digiphot/apphot/lib/radprof.h b/noao/digiphot/apphot/lib/radprof.h
new file mode 100644
index 00000000..56572c50
--- /dev/null
+++ b/noao/digiphot/apphot/lib/radprof.h
@@ -0,0 +1,66 @@
+# RADPROF header file
+
+# radprof error codes (# 901 - 1000)
+
+define	AP_OK			0
+define	AP_RP_NOPROFILE		901
+define	AP_RP_OUTOFBOUNDS	902
+define	AP_RP_NPTS_TOO_SMALL	903
+define	AP_RP_SINGULAR		904
+define	AP_RP_NOSKYMODE		905
+
+# radprof fit parameters and answers (# 901 - 1000)
+
+define	RPXCUR			901
+define	RPYCUR			902
+define	ORPXCUR			903
+define	ORPYCUR			904
+define	RPRADIUS		905
+define	RPSTEP			906
+define	RPKSIGMA		907
+define	RPNREJECT		908
+define	RPORDER			909
+define	INORM			910
+define	TNORM			911
+define	DNORM			912
+define	RPFWHM			913
+define	RPNPTS			914
+define	RPNDATA			915
+define	RPNDATAREJ		916
+
+# define radprof keywords
+
+define	KY_RPRADIUS	"radius"
+define	KY_RPSTEP	"stepsize"
+define	KY_RPORDER	"order"
+define	KY_RPKSIGMA	"kreject"
+define	KY_RPNREJECT	"nreject"
+
+# define radprof units
+
+#define	UN_RPRADIUS	"scaleunit"
+#define	UN_RPSTEP	"scaleunit"
+#define	UN_RPORDER	"number"
+#define	UN_RPKSIGMA	"sigma"
+#define	UN_RPNREJECT	"number"
+
+define	UN_RSCALEUNIT	"scaleunit"
+define	UN_RNUMBER	"number"
+define	UN_RSIGMA	"sigma"
+
+# radprof strings
+
+define	RPSHOWARGS	"|center|sky|phot|fit|data|"
+define	RPCMDS		"|radius|stepsize|order|kreject|nreject|"
+
+define	RCMD_CENTER	1
+define	RCMD_SKY	2
+define	RCMD_PHOT	3
+define	RCMD_FIT	4
+define	RCMD_DATA	5
+
+define	RCMD_RADIUS	1
+define	RCMD_STEPSIZE	2
+define	RCMD_ORDER	3
+define	RCMD_KREJECT 	4
+define	RCMD_NREJECT 	5
diff --git a/noao/digiphot/apphot/lib/radprofdef.h b/noao/digiphot/apphot/lib/radprofdef.h
new file mode 100644
index 00000000..1fcb3dcc
--- /dev/null
+++ b/noao/digiphot/apphot/lib/radprofdef.h
@@ -0,0 +1,38 @@
+# RADPROF header file
+
+define	LEN_RPSTRUCT	30
+
+# Radprof data parameters
+
+define  AP_RPXCUR	Memr[P2R($1)]	# X image center in pixels
+define	AP_RPYCUR	Memr[P2R($1+1)]	# Y image center in pixels
+define	AP_RPIX		Memi[$1+2]	# Pointer to radial profile pixels
+define	AP_RPXC		Memr[P2R($1+3)]	# X center of subraster
+define	AP_RPYC		Memr[P2R($1+4)]	# Y center of subraster
+define	AP_RPNX		Memi[$1+5]	# Subraster length in x
+define	AP_RPNY		Memi[$1+6]	# Subraster length in y
+define  AP_ORPXCUR	Memr[P2R($1+7)]	# output system X image center in pixels
+define	AP_ORPYCUR	Memr[P2R($1+8)]	# output system Y image center in pixels
+
+# Radprof fit parameters
+
+define	AP_RPRADIUS	Memr[P2R($1+9)]	# Radprof radius in scale
+define	AP_RPSTEP	Memr[P2R($1+10)]# Radprof step size in scale
+define	AP_RPORDER	Memi[$1+11]	# Order of the spline3 fit
+define	AP_RPKSIGMA	Memr[P2R($1+12)]# Radprof K-rejection criterion in sigma
+define	AP_RPNREJECT	Memi[$1+13]	# Maximum number of rejection cycles
+
+# Radprof answers
+
+define	AP_RPNPTS	Memi[$1+14]	# Number of points in radial profile
+define	AP_RPDIST	Memi[$1+15]	# Pointer to radial distance array
+define	AP_INTENSITY	Memi[$1+16]	# Pointer to fitted intensity array
+define	AP_DINTENSITY	Memi[$1+17]	# Pointer incremental intensity array
+define	AP_TINTENSITY	Memi[$1+18]	# Pointer to total intensity array
+define	AP_INORM	Memr[P2R($1+19)]# Normalization for intensity profile
+define	AP_TINORM	Memr[P2R($1+20)]# Normalization for total intensity
+define	AP_DNORM	Memr[P2R($1+21)]# Normalization for incremental inten
+define	AP_RPFWHM	Memr[P2R($1+22)]# Fitted profile FWHM
+define	AP_RPNDATA	Memi[$1+23]	# Number of data points
+define	AP_RPNDATAREJ	Memi[$1+24]	# Number of points rejected from fit
+define	AP_RPNBAD	Memi[$1+25]	# Number of bad pixel points
diff --git a/noao/digiphot/apphot/mkpkg b/noao/digiphot/apphot/mkpkg
new file mode 100644
index 00000000..861aeea4
--- /dev/null
+++ b/noao/digiphot/apphot/mkpkg
@@ -0,0 +1,39 @@
+# Make the APPHOT package
+
+$call relink
+$exit
+
+update:
+	$call relink
+	$call install
+	;
+
+relink:
+	$set LIBS = "-lnlfit -liminterp -lcurfit -lds -lxtools"
+	$update libpkg.a
+	$omake x_apphot.x
+	$link x_apphot.o libpkg.a $(LIBS) -o xx_apphot.e
+	;
+
+linkonly:
+	$set LIBS = "-lnlfit -liminterp -lcurfit -lds -lxtools"
+	$link x_apphot.o libpkg.a $(LIBS) -o xx_apphot.e
+	$call install
+	;
+
+install:
+	$move xx_apphot.e noaobin$x_apphot.e
+	;
+
+libpkg.a:
+	@aplib
+	@aputil
+	@center
+	@daofind
+	@fitpsf
+	@fitsky
+	@phot
+	@polyphot
+	@radprof
+	@wphot
+	;
diff --git a/noao/digiphot/apphot/pexamine.par b/noao/digiphot/apphot/pexamine.par
new file mode 100644
index 00000000..809e2943
--- /dev/null
+++ b/noao/digiphot/apphot/pexamine.par
@@ -0,0 +1,20 @@
+# The PEXAMINE task parameter set
+
+input,s,a,,,,"Name of the input catalog"
+output,s,a,"",,,"Name of the edited output catalog"
+image,s,a,"",,,Name of the image corresponding to the input catalog
+deletions,s,h,"",,,"Name of the output catalog for deleted entries"
+photcolumns,s,h,"apphot",,,"Names of the standard photometry columns"
+xcolumn,s,h,mag,,,"Catalog column which is the X axis of X-Y plot"
+ycolumn,s,h,merr,,,"Catalog column which is the Y axis of X-Y plot"
+hcolumn,s,h,mag,,,"Catalog column which is to be binned"
+xposcolumn,s,h,"xcenter",,,"Name of the x coordinate column"
+yposcolumn,s,h,"ycenter",,,"Name of the y coordinate column"
+usercolumns,s,h,"",,,"Names of additional user selected columns"
+first_star,i,h,1,1,,First star in the catalog to load
+max_nstars,i,h,5000,1,,Maximum number of stars to load
+match_radius,r,h,2.0,,,Matching radius for positional coincidence on display
+graphics,s,h,"stdgraph",,,The graphics device
+use_display,b,h,yes,,,Use the image display ?
+icommands,*imcur,h,"",,,"Image cursor: [x y wcs] key [cmd]"
+gcommands,*gcur,h,"",,,"Graphics cursor: [x y wcs] key [cmd]"
diff --git a/noao/digiphot/apphot/phot.par b/noao/digiphot/apphot/phot.par
new file mode 100644
index 00000000..87570ac2
--- /dev/null
+++ b/noao/digiphot/apphot/phot.par
@@ -0,0 +1,24 @@
+# PHOT parameters
+
+image,f,a,,,,"The input image(s)"
+skyfile,f,a,"",,,"The input sky file(s)"
+coords,f,h,"",,,"The input coordinate files(s) (default: image.coo.?)"
+output,f,h,"default",,,"The output photometry file(s) (default: image.mag.?)"
+plotfile,f,h,"",,,"The output plots metacode file"
+datapars,pset,h,"",,,"Data dependent parameters"
+centerpars,pset,h,"",,,"Centering parameters"
+fitskypars,pset,h,"",,,"Sky fitting parameters"
+photpars,pset,h,"",,,"Photometry parameters"
+interactive,b,h,yes,,,"Interactive mode ?"
+radplots,b,h,no,,,"Plot the radial profiles in interactive mode ?"
+icommands,*imcur,h,"",,,"Image cursor: [x y wcs] key [cmd]"
+gcommands,*gcur,h,"",,,"Graphics cursor: [x y wcs] key [cmd]"
+wcsin,s,h,)_.wcsin,,,"The input coordinate system (logical,tv,physical,world)"
+wcsout,s,h,)_.wcsout,,,"The output coordinate system (logical,tv,physical)"
+cache,b,h,)_.cache,,,"Cache the input image pixels in memory ?"
+verify,b,h,)_.verify,,,"Verify critical parameters in non-interactive mode ?"
+update,b,h,)_.update,,,"Update critical parameters in non-interactive mode ?"
+verbose,b,h,)_.verbose,,,"Print messages in non-interactive mode ?"
+graphics,s,h,)_.graphics,,,"Graphics device"
+display,s,h,)_.display,,,"Display device"
+mode,s,h,'ql'
diff --git a/noao/digiphot/apphot/phot/apbphot.x b/noao/digiphot/apphot/phot/apbphot.x
new file mode 100644
index 00000000..ea6ee325
--- /dev/null
+++ b/noao/digiphot/apphot/phot/apbphot.x
@@ -0,0 +1,115 @@
+include <fset.h>
+include "../lib/apphot.h"
+include "../lib/display.h"
+include "../lib/center.h"
+include "../lib/fitsky.h"
+
+# APBPHOT -- Procedure to compute the magnitudes for a list of objects
+# interactively.
+
+procedure apbphot (ap, im, cl, sd, out, id, ld, gd, mgd, gid, interactive)
+
+pointer ap			# pointer to apphot structure
+pointer	im			# pointer to IRAF image
+int	cl			# starlist file descriptor
+int	sd			# sky file descriptor
+int	out			# output file descriptor
+int	id, ld			# sequence and list numbers
+pointer	gd			# pointer to stdgraph stream
+pointer	mgd			# pointer to plot metacode file
+pointer	gid			# pointer to image display stream
+int	interactive		# interactive pr batch mode
+
+int	stdin, ild, radius, cier, sier, pier
+pointer	sp, str
+real	wx, wy
+int	fscan(), nscan(), apfitsky(), apfitcenter(), apmag(), strncmp()
+int	apstati()
+real	apstatr()
+
+begin
+	call smark (sp)
+	call salloc (str, SZ_FNAME, TY_CHAR)
+	call fstats (cl, F_FILENAME, Memc[str], SZ_FNAME)
+
+	# Initialize
+	ild = ld
+	radius = 4 * (apstatr (ap, ANNULUS) + apstatr (ap, DANNULUS) + 1.0) *
+	    apstatr (ap, SCALE)
+	call ap_imbuf (ap, radius, YES)
+
+	# Print query.
+	if (strncmp ("STDIN", Memc[str], 5) == 0) {
+	    stdin = YES
+	    call printf ("Type object x and y coordinates (^D or ^Z to end): ")
+	    call flush (STDOUT)
+	} else
+	    stdin = NO
+
+	# Loop over the coordinate file.
+	while (fscan (cl) != EOF) {
+
+	    # Get and store the coordinates.
+	    call gargr (wx)
+	    call gargr (wy)
+	    if (nscan () != 2) {
+		if (stdin == YES) {
+	    	    call printf (
+		        "Type object x and y coordinates (^D or ^Z to end): ")
+	    	    call flush (STDOUT)
+		}
+		next
+	    }
+
+
+            # Transform the input coordinates.
+            switch (apstati(ap,WCSIN)) {
+            case WCS_WORLD, WCS_PHYSICAL:
+                call ap_itol (ap, wx, wy, wx, wy, 1)
+            case WCS_TV:
+                call ap_vtol (im, wx, wy, wx, wy, 1)
+            default:
+                ;
+            }
+	    call apsetr (ap, CWX, wx)
+	    call apsetr (ap, CWY, wy)
+
+	    # Center the coordinates, fit the sky and compute magnitudes.
+	    cier = apfitcenter (ap, im, wx, wy)
+	    sier = apfitsky (ap, im, apstatr (ap, XCENTER), apstatr (ap,
+	        YCENTER), sd, gd)
+	    pier = apmag (ap, im, apstatr (ap, XCENTER), apstatr (ap, YCENTER),
+	        apstati (ap, POSITIVE), apstatr (ap, SKY_MODE),
+		apstatr (ap, SKY_SIGMA), apstati (ap, NSKY))
+
+	    # Print the results if interactive mode.
+	    if (interactive == YES) {
+		call ap_qpmag (ap, cier, sier, pier)
+		if (gid != NULL)
+		    call apmark (ap, gid, apstati (ap, MKCENTER), apstati (ap,
+			MKSKY), apstati (ap, MKAPERT))
+	    }
+
+	    # Write the results.
+	    if (id == 1)
+	        call ap_param (ap, out, "phot")
+	    call ap_pmag (ap, out, id, ild, cier, sier, pier)
+
+	    # Make plots if mgd is enabled.
+	    call ap_pplot (ap, im, id, mgd, YES)
+
+	    # Prepare for the next object.
+	    id = id + 1
+	    ild = ild + 1
+	    call apsetr (ap, WX, wx)
+	    call apsetr (ap, WY, wy)
+	    if (stdin == YES) {
+		call printf (
+		    "Type object x and y coordinates (^Z or ^D to end): ")
+		call flush (STDOUT)
+	    }
+	}
+
+	call ap_imbuf (ap, 0, YES)
+	call sfree (sp)
+end
diff --git a/noao/digiphot/apphot/phot/apcomags.x b/noao/digiphot/apphot/phot/apcomags.x
new file mode 100644
index 00000000..c6d15a16
--- /dev/null
+++ b/noao/digiphot/apphot/phot/apcomags.x
@@ -0,0 +1,118 @@
+include <mach.h>
+include "../lib/noise.h"
+
+# APCOPMAGS -- Procedure to compute the magnitudes from the aperture sums,
+# areas and sky values.
+
+procedure apcopmags (sums, areas, mags, magerrs, naperts, sky, sigma, nsky,
+    zmag, noise, padu)
+
+double	sums[ARB]		# aperture sums
+double	areas[ARB]		# aperture areas
+real	mags[ARB]		# output magnitudes
+real	magerrs[ARB]		# errors in the magnitudes
+int	naperts			# number of apertures
+real	sky			# sky value
+real	sigma			# sigma of the sky values
+int	nsky			# number of sky pixels
+real	zmag			# sky value, sigma and zero point magnitudes
+int	noise			# noise model
+real	padu			# photons per adu
+
+int	i
+real	err1, err2, err3, err
+
+begin
+	# Compute the magnitudes and errors
+	do i = 1, naperts {
+	    mags[i] = sums[i] - areas[i] * sky
+	    if (mags[i] <= 0.0)
+		mags[i] = INDEFR
+	    else {
+		if (IS_INDEFR(sigma))
+		    err1 = 0.0
+		else
+		    err1 = areas[i] * sigma ** 2
+		switch (noise) {
+		case AP_NCONSTANT:
+		    err2 = 0.0
+		case AP_NPOISSON:
+		    err2 = mags[i] / padu
+		default:
+		    err2 = 0.0
+		}
+		if (nsky <= 0)
+		    err3 = 0.0
+		else if (IS_INDEFR(sigma))
+		    err3 = 0.0
+		else
+		    err3 = sigma ** 2 * areas[i] ** 2 / nsky
+		err = err1 + err2 + err3
+		if (err <= 0.0)
+		    magerrs[i] = 0.0
+		else {
+		    magerrs[i] = 1.0857 * sqrt (err) / mags[i]
+		}
+		mags[i] = zmag - 2.5 * log10 (mags[i])
+	    }
+	}
+end
+
+
+# APCONMAGS -- Procedure to compute the magnitudes from the aperture sums,
+# areas and sky values.
+
+procedure apconmags (sums, areas, mags, magerrs, naperts, sky, sigma, nsky,
+    zmag, noise, padu, readnoise)
+
+double	sums[ARB]		# aperture sums
+double	areas[ARB]		# aperture areas
+real	mags[ARB]		# output magnitudes
+real	magerrs[ARB]		# errors in the magnitudes
+int	naperts			# number of apertures
+real	sky			# sky value
+real	readnoise		# readout noise in electrons
+real	sigma			# sigma of the sky values
+int	nsky			# number of sky pixels
+real	zmag			# sky value, sigma and zero point magnitudes
+int	noise			# noise model
+real	padu			# photons per adu
+
+int	i
+real	err1, err2, err3, err
+
+begin
+	# Compute the magnitudes and errors
+	do i = 1, naperts {
+	    mags[i] = areas[i] * sky - sums[i]
+	    if (mags[i] <= 0.0)
+		mags[i] = INDEFR
+	    else {
+		if (IS_INDEFR(readnoise))
+		    err1 = 0.0
+		else
+		    err1 = areas[i] * (readnoise / padu) ** 2
+		switch (noise) {
+		case AP_NCONSTANT:
+		    err2 = 0.0
+		case AP_NPOISSON:
+		    err2 = abs (sums[i]) / padu
+		default:
+		    err2 = 0.0
+		}
+		if (nsky <= 0)
+		    err3 = 0.0
+		else if (IS_INDEFR(sigma))
+		    err3 = 0.0
+		else
+		    err3 = sigma ** 2 * areas[i] ** 2 / nsky
+		err = err1 + err2 + err3
+		if (err <= 0.0)
+		    magerrs[i] = 0.0
+		else {
+		    magerrs[i] = 1.0857 * sqrt (err) / abs (sums[i])
+		}
+		mags[i] = zmag - 2.5 * log10 (mags[i])
+	    }
+	}
+end
diff --git a/noao/digiphot/apphot/phot/apgppars.x b/noao/digiphot/apphot/phot/apgppars.x
new file mode 100644
index 00000000..09961678
--- /dev/null
+++ b/noao/digiphot/apphot/phot/apgppars.x
@@ -0,0 +1,35 @@
+include "../lib/display.h"
+include "../lib/noise.h"
+include "../lib/center.h"
+include "../lib/fitsky.h"
+include "../lib/phot.h"
+
+# AP_GPPARS -- Procedure to fetch the phot task parameters.
+
+procedure ap_gppars (ap)
+
+pointer	ap		# pointer to apphot structure
+
+bool	clgetb()
+int	btoi()
+
+begin
+	# Open the apphot strucuture.
+	call appinit (ap, AP_CENTROID1D, 2.5, AP_MODE, 10.0, 10.0, 3.0, 1,
+	    AP_PWCONSTANT, 2.0, AP_NPOISSON)
+
+	# Get the data dependent parameters.
+	call ap_gdapars (ap)
+
+	# Get the centering algorithm parameters.
+	call ap_gcepars (ap)
+
+	# Get the sky fitting parameters.
+	call ap_gsapars (ap)
+
+	# Get the photometry parameters.
+	call ap_gphpars (ap)
+
+	# Get the plotting parameters.
+	call apseti (ap, RADPLOTS, btoi (clgetb ("radplots")))
+end
diff --git a/noao/digiphot/apphot/phot/apgqppars.x b/noao/digiphot/apphot/phot/apgqppars.x
new file mode 100644
index 00000000..dea31951
--- /dev/null
+++ b/noao/digiphot/apphot/phot/apgqppars.x
@@ -0,0 +1,75 @@
+include "../lib/apphot.h"
+include "../lib/display.h"
+include "../lib/noise.h"
+include "../lib/center.h"
+include "../lib/fitsky.h"
+include "../lib/phot.h"
+
+# AP_GQPPARS -- Procedure to fetch the phot task parameters.
+
+procedure ap_gqppars (ap)
+
+pointer	ap		# pointer to apphot structure
+
+int	naperts
+pointer	mp, aperts, str, apstr
+real	cbox, annulus, dannulus
+bool	clgetb()
+int	ap_getaperts(), btoi()
+real	clgetr()
+
+begin
+	call smark (mp)
+	call salloc (aperts, MAX_NAPERTS, TY_REAL)
+	call salloc (str, SZ_LINE, TY_CHAR)
+	call salloc (apstr, SZ_LINE, TY_CHAR)
+
+	# Get the center, sky fitting and photometry apertures.
+	cbox = clgetr ("cbox") / 2.0
+	annulus = clgetr ("annulus")
+	dannulus = clgetr ("dannulus")
+	call clgstr ("apertures", Memc[apstr], SZ_LINE)
+	naperts = ap_getaperts (Memc[apstr], Memr[aperts], MAX_NAPERTS)
+
+	# Open the apphot structure.
+	if (naperts <= 0.0)
+	    call appinit (ap, AP_CENTROID1D, cbox, AP_CENTROID, annulus,
+	        dannulus, 0.0, 1, AP_PWCONSTANT, 2.5, AP_NPOISSON) 
+	else
+	    call appinit (ap, AP_CENTROID1D, cbox, AP_CENTROID, annulus,
+	        dannulus, Memr[aperts], naperts, AP_PWCONSTANT, 2.5,
+		AP_NPOISSON) 
+
+	# Set remaining parameters.
+	call apseti (ap, SMOOTH, YES)
+
+	if (naperts > 0)
+	    call apsets (ap, APSTRING, Memc[apstr])
+	call apsetr (ap, ZMAG, clgetr ("zmag"))
+
+	call clgstr ("exposure", Memc[str], SZ_FNAME)
+	call apsets (ap, EXPOSURE, Memc[str])
+
+	call clgstr ("airmass", Memc[str], SZ_FNAME)
+	call apsets (ap, AIRMASS, Memc[str])
+	call apsetr (ap, XAIRMASS, INDEFR)
+
+	call clgstr ("filter", Memc[str], SZ_FNAME)
+	call apsets (ap, FILTER, Memc[str])
+	call apsets (ap, FILTERID, "INDEF")
+
+	call clgstr ("obstime", Memc[str], SZ_FNAME)
+	call apsets (ap, OBSTIME, Memc[str])
+	call apsets (ap, OTIME, "INDEF")
+
+	call apsetr (ap, EPADU, clgetr ("epadu"))
+
+	# Print the display parameters.
+	call apseti (ap, MKCENTER, btoi (true))
+	call apseti (ap, MKSKY, btoi (true))
+	call apseti (ap, MKAPERT, btoi (true))
+	call apseti (ap, RADPLOTS, btoi (clgetb ("radplots")))
+
+	# Close the pset files.
+	call sfree (mp)
+end
diff --git a/noao/digiphot/apphot/phot/apmag.x b/noao/digiphot/apphot/phot/apmag.x
new file mode 100644
index 00000000..e1490be2
--- /dev/null
+++ b/noao/digiphot/apphot/phot/apmag.x
@@ -0,0 +1,118 @@
+include <mach.h>
+include "../lib/apphotdef.h"
+include "../lib/apphot.h"
+include "../lib/noisedef.h"
+include "../lib/photdef.h"
+include "../lib/phot.h"
+
+# APMAG -- Procedure to compute the magnitudes inside a set of apertures for
+# a single of object.
+
+int procedure apmag (ap, im, wx, wy, positive, skyval, skysig, nsky)
+
+pointer	ap		# pointer to the apphot structure
+pointer	im		# pointer to the IRAF image
+real	wx, wy		# object coordinates
+int	positive	# emission or absorption features
+real	skyval		# sky value
+real	skysig		# sky sigma
+int	nsky		# number of sky pixels
+
+int	c1, c2, l1, l2, ier, nap
+pointer	sp, nse, phot, temp
+real	datamin, datamax, zmag
+int	apmagbuf()
+
+begin
+	# Initalize.
+	phot = AP_PPHOT(ap)
+	nse = AP_NOISE(ap)
+	AP_PXCUR(phot) = wx
+	AP_PYCUR(phot) = wy
+        if (IS_INDEFR(wx) || IS_INDEFR(wy)) {
+            AP_OPXCUR(phot) = INDEFR
+            AP_OPYCUR(phot) = INDEFR
+        } else {
+            switch (AP_WCSOUT(ap)) {
+            case WCS_WORLD, WCS_PHYSICAL:
+                call ap_ltoo (ap, wx, wy, AP_OPXCUR(phot), AP_OPYCUR(phot), 1)
+            case WCS_TV:
+                call ap_ltov (im, wx, wy, AP_OPXCUR(phot), AP_OPYCUR(phot), 1)
+            default:
+                AP_OPXCUR(phot) = wx
+                AP_OPYCUR(phot) = wy
+            }
+        }
+
+	call amovkd (0.0d0, Memd[AP_SUMS(phot)], AP_NAPERTS(phot))
+	call amovkd (0.0d0, Memd[AP_AREA(phot)], AP_NAPERTS(phot))
+	call amovkr (INDEFR, Memr[AP_MAGS(phot)], AP_NAPERTS(phot))
+	call amovkr (INDEFR, Memr[AP_MAGERRS(phot)], AP_NAPERTS(phot))
+
+	# Make sure the center is defined.
+	if (IS_INDEFR(wx) || IS_INDEFR(wy))
+	    return (AP_APERT_NOAPERT)
+
+	# Fetch the aperture pixels.
+	ier = apmagbuf (ap, im, wx, wy, c1, c2, l1, l2)
+	if (ier == AP_APERT_NOAPERT)
+	    return (AP_APERT_NOAPERT)
+
+	call smark (sp)
+	call salloc (temp, AP_NAPERTS(phot), TY_REAL)
+
+	# Do photometry for all the apertures.
+	call amulkr (Memr[AP_APERTS(phot)], AP_SCALE(ap), Memr[temp],
+	    AP_NAPERTS(phot)]
+	if (IS_INDEFR(AP_DATAMIN(ap)) && IS_INDEFR(AP_DATAMAX(ap))) {
+	    call  apmeasure (im, wx, wy, c1, c2, l1, l2, Memr[temp],
+	        Memd[AP_SUMS(phot)], Memd[AP_AREA(phot)], AP_NMAXAP(phot))
+	    AP_NMINAP(phot) = AP_NMAXAP(phot) + 1
+	} else {
+	    if (IS_INDEFR(AP_DATAMIN(ap)))
+		datamin = -MAX_REAL
+	    else
+		datamin = AP_DATAMIN(ap)
+	    if (IS_INDEFR(AP_DATAMAX(ap)))
+		datamax = MAX_REAL
+	    else
+		datamax = AP_DATAMAX(ap)
+	    call  apbmeasure (im, wx, wy, c1, c2, l1, l2, datamin, datamax,
+	        Memr[temp], Memd[AP_SUMS(phot)], Memd[AP_AREA(phot)],
+		AP_NMAXAP(phot), AP_NMINAP(phot))
+	}
+
+	# Make sure that the sky value has been defined.
+	if (IS_INDEFR(skyval))
+	    ier = AP_APERT_NOSKYMODE
+	else {
+
+	    # Check for bad pixels.
+	    if ((ier == AP_OK) && (AP_NMINAP(phot) <= AP_NMAXAP(phot)))
+		ier = AP_APERT_BADDATA
+
+	    nap = min (AP_NMINAP(phot) - 1, AP_NMAXAP(phot))
+
+	    # Compute the magnitudes and errors.
+	    if (positive == YES)
+	        call apcopmags (Memd[AP_SUMS(phot)], Memd[AP_AREA(phot)],
+	            Memr[AP_MAGS(phot)], Memr[AP_MAGERRS(phot)],
+		    nap, skyval, skysig, nsky, AP_ZMAG(phot),
+		    AP_NOISEFUNCTION(nse), AP_EPADU(nse))
+	    else
+	        call apconmags (Memd[AP_SUMS(phot)], Memd[AP_AREA(phot)],
+	            Memr[AP_MAGS(phot)], Memr[AP_MAGERRS(phot)],
+		    nap, skyval, skysig, nsky, AP_ZMAG(phot),
+		    AP_NOISEFUNCTION(nse), AP_EPADU(nse), AP_READNOISE(nse))
+
+	    # Compute correction for itime.
+	    zmag = 2.5 * log10 (AP_ITIME(ap))
+	    call aaddkr (Memr[AP_MAGS(phot)], zmag, Memr[AP_MAGS(phot)], nap)
+	}
+
+	call sfree (sp)
+	if (ier != AP_OK)
+	    return (ier)
+	else
+	    return (AP_OK)
+end
diff --git a/noao/digiphot/apphot/phot/apmagbuf.x b/noao/digiphot/apphot/phot/apmagbuf.x
new file mode 100644
index 00000000..15034561
--- /dev/null
+++ b/noao/digiphot/apphot/phot/apmagbuf.x
@@ -0,0 +1,89 @@
+include <imhdr.h>
+include "../lib/apphotdef.h"
+include "../lib/photdef.h"
+include "../lib/phot.h"
+
+# APMAGBUF -- Procedure to determine the mapping of the aperture list
+# into the input image.
+
+int procedure apmagbuf (ap, im, wx, wy, c1, c2, l1, l2)
+
+pointer	ap		# pointer to apphot structure
+pointer	im		# pointer to the IRAF image
+real	wx, wy		# center coordinates
+int	c1, c2		# column limits
+int	l1, l2		# line limits
+
+int	i
+pointer	phot
+real	rbuf
+int	ap_photpix()
+
+begin
+	# Check for 0 radius aperture.
+	phot = AP_PPHOT(ap)
+	if (Memr[AP_APERTS(phot)] <= 0.0)
+	    return (AP_APERT_NOAPERT)
+
+	# Compute the maximum aperture size
+	AP_APIX(phot) = NULL
+	for (i = AP_NAPERTS(phot); AP_APIX(phot) == NULL && i >= 1; i = i - 1) {
+	    rbuf =  2. * Memr[AP_APERTS(phot)+i-1] * AP_SCALE(ap)
+	    AP_APIX(phot) = ap_photpix (im, wx, wy, rbuf, c1, c2, l1, l2)
+	    AP_AXC(phot) = wx - c1 + 1 
+	    AP_AYC(phot) = wy - l1 + 1
+	    AP_ANX(phot) = c2 - c1 + 1
+	    AP_ANY(phot) = l2 - l1 + 1
+	    AP_NMAXAP(phot) = i
+	}
+
+	# Return the appropriate error code.
+	if (AP_APIX(phot) == NULL) {
+	    return (AP_APERT_NOAPERT)
+	} else if (AP_NMAXAP(phot) < AP_NAPERTS(phot)) {
+	    return (AP_APERT_OUTOFBOUNDS)
+	} else {
+	    return (AP_OK)
+	}
+end
+
+
+# AP_PHOTPIX -- Procedure to determine the line and column limits of the
+# required subraster.
+
+int procedure ap_photpix (im, wx, wy, papert, c1, c2, l1, l2)
+
+pointer	im		# pointer to IRAF image
+real	wx, wy		# center of centering subraster annulus
+real	papert		# centering radius
+int	c1, c2		# column limits
+int	l1, l2		# line limits
+
+int	ncols, nlines
+real	half_papert, xc1, xc2, xl1, xl2
+
+begin
+	# Check for 0 radius aperture.
+	half_papert = papert / 2.
+	if (half_papert <= 0)
+	    return (0)
+	ncols = IM_LEN(im,1)
+	nlines = IM_LEN(im,2)
+
+	# Test for an out of bounds aperture.
+	xc1 = wx - half_papert
+	xc2 = wx + half_papert
+	xl1 = wy - half_papert
+	xl2 = wy + half_papert
+	if ((xc1 < 0.5) || (xc2 > (real (ncols) + 0.5)) ||
+	    (xl1 < 0.5) || (xl2 > (real (nlines) + 0.5)))
+	    return (0)
+
+	# Get the column and line limits, dimensions and center of the subraster
+	# to be extracted.
+	c1 = max (1.0, min (real (ncols), xc1))
+	c2 = min (real (ncols), max (1.0, xc2 + 0.5))
+	l1 = max (1.0, min (real (nlines), xl1))
+	l2 = min (real (nlines), max (1.0, xl2 + 0.5))
+	return ((c2 - c1 + 1) * (l2 - l1 + 1))
+end
diff --git a/noao/digiphot/apphot/phot/apmeasure.x b/noao/digiphot/apphot/phot/apmeasure.x
new file mode 100644
index 00000000..6d64db5e
--- /dev/null
+++ b/noao/digiphot/apphot/phot/apmeasure.x
@@ -0,0 +1,116 @@
+# APMEASURE -- Procedure to measure the fluxes and effective areas of a set of
+# apertures.
+
+procedure apmeasure (im, wx, wy, c1, c2, l1, l2, aperts, sums, areas, naperts)
+
+pointer	im			# pointer to image
+real	wx, wy			# center of subraster
+int	c1, c2			# column limits
+int	l1, l2			# line limits
+real	aperts[ARB]		# array of apertures
+double	sums[ARB]		# array of sums
+double	areas[ARB]		# aperture areas
+int	naperts			# number of apertures
+
+int	i, j, k, nx, yindex
+double	fctn
+pointer	buf
+real	xc, yc, apmaxsq, dy2, r2, r
+pointer	imgs2r()
+
+begin
+	# Initialize.
+	nx = c2 - c1 + 1
+	xc = wx - c1 + 1
+	yc = wy - l1 + 1
+	apmaxsq = (aperts[naperts] + 0.5) ** 2
+	call aclrd (sums, naperts)
+	call aclrd (areas, naperts)
+
+	# Loop over the pixels.
+	do j = l1, l2 {
+	    buf = imgs2r (im, c1, c2, j, j)
+	    if (buf == NULL)
+		return
+	    yindex = j - l1 + 1
+	    dy2 = (yindex - yc) ** 2
+	    do i = 1, nx {
+		r2 = (i - xc) ** 2 + dy2
+		if (r2 > apmaxsq)
+		    next
+		r = sqrt (r2) - 0.5
+		do k = 1, naperts {
+		    if (r > aperts[k])
+			next
+		    fctn = max (0.0, min (1.0, aperts[k] - r))
+		    sums[k] = sums[k] + fctn * Memr[buf+i-1]
+		    areas[k] = areas[k] + fctn
+		}
+	    }
+	}
+end
+
+
+# APBMEASURE -- Procedure to measure the fluxes and effective areas of a set of
+# apertures.
+
+procedure apbmeasure (im, wx, wy, c1, c2, l1, l2, datamin, datamax, aperts,
+	sums, areas, naperts, minapert)
+
+pointer	im			# pointer to image
+real	wx, wy			# center of subraster
+int	c1, c2			# column limits
+int	l1, l2			# line limits
+real	datamin			# minimum good data value
+real	datamax			# maximum good data value
+real	aperts[ARB]		# array of apertures
+double	sums[ARB]		# array of sums
+double	areas[ARB]		# aperture areas
+int	naperts			# number of apertures
+int	minapert		# minimum apertures
+
+int	i, j, k, nx, yindex, kindex
+double	fctn
+pointer	buf
+real	xc, yc, apmaxsq, dy2, r2, r, pixval
+pointer	imgs2r()
+
+begin
+	# Initialize.
+	nx = c2 - c1 + 1
+	xc = wx - c1 + 1
+	yc = wy - l1 + 1
+	apmaxsq = (aperts[naperts] + 0.5) ** 2
+	call aclrd (sums, naperts)
+	call aclrd (areas, naperts)
+	minapert = naperts + 1
+
+	# Loop over the pixels.
+	do j = l1, l2 {
+	    buf = imgs2r (im, c1, c2, j, j)
+	    if (buf == NULL)
+		return
+	    yindex = j - l1 + 1
+	    dy2 = (yindex - yc) ** 2
+	    do i = 1, nx {
+		r2 = (i - xc) ** 2 + dy2
+		if (r2 > apmaxsq)
+		    next
+		r = sqrt (r2) - 0.5
+		pixval = Memr[buf+i-1]
+		kindex = naperts + 1
+		do k = 1, naperts {
+		    if (r > aperts[k])
+			next
+		    kindex = min (k, kindex)
+		    fctn = max (0.0, min (1.0, aperts[k] - r))
+		    sums[k] = sums[k] + fctn * pixval
+		    areas[k] = areas[k] + fctn
+		}
+		if (kindex < minapert) {
+		    if (pixval < datamin || pixval > datamax)
+		        minapert = kindex
+		}
+	    }
+	}
+end
diff --git a/noao/digiphot/apphot/phot/appconfirm.x b/noao/digiphot/apphot/phot/appconfirm.x
new file mode 100644
index 00000000..53d24034
--- /dev/null
+++ b/noao/digiphot/apphot/phot/appconfirm.x
@@ -0,0 +1,98 @@
+include "../lib/apphot.h"
+include "../lib/noise.h"
+include "../lib/center.h"
+include "../lib/fitsky.h"
+include "../lib/phot.h"
+
+# AP_PCONFIRM -- Procedure to confirm the critical phot parameters.
+
+procedure ap_pconfirm (ap, out, stid)
+
+pointer	ap		# pointer to the apphot structure
+int	out		# output file descriptor
+int	stid		# output file sequence number
+
+pointer	sp, cstr, sstr, aperts
+real	fwhmpsf, capert, annulus, dannulus, skysigma
+real	datamin, datamax
+int	apstati()
+real	apstatr(), ap_vcapert(), ap_vannulus(), ap_vdannulus(), ap_vsigma()
+real	ap_vfwhmpsf(), ap_vdatamin(), ap_vdatamax
+
+begin
+	call smark (sp)
+	call salloc (cstr, SZ_FNAME, TY_CHAR)
+	call salloc (sstr, SZ_FNAME, TY_CHAR)
+	call salloc (aperts, SZ_LINE, TY_CHAR)
+
+	call printf ("\n")
+
+	# Confirm the centering algorithm.
+	call ap_vcstring (ap, Memc[cstr], SZ_FNAME)
+
+	if (apstati (ap, CENTERFUNCTION) != AP_NONE) {
+
+	    # Confirm the fwhmpsf.
+	    if (apstati (ap, CENTERFUNCTION) != AP_CENTROID1D)
+		fwhmpsf = ap_vfwhmpsf (ap)
+	    else
+		fwhmpsf = apstatr (ap, FWHMPSF)
+
+	    # Confirm the centering box.
+	    capert = 2.0 * ap_vcapert (ap)
+
+	} else {
+
+	    fwhmpsf = apstatr (ap, FWHMPSF)
+	    capert = 2.0 * apstatr (ap, CAPERT)
+	}
+
+	# Confirm the sky fitting algorithm.
+	call ap_vsstring (ap, Memc[sstr], SZ_FNAME)
+
+	# Confirm the sky annulus.
+	if (apstati (ap, SKYFUNCTION) != AP_CONSTANT &&
+	    apstati (ap, SKYFUNCTION) != AP_SKYFILE) {
+	    annulus = ap_vannulus (ap)
+	    dannulus = ap_vdannulus (ap)
+	} else {
+	    annulus = apstatr (ap, ANNULUS)
+	    dannulus = apstatr (ap, DANNULUS)
+	}
+
+	# Confirm the aperture radii parameter.
+	call ap_vaperts (ap, Memc[aperts], SZ_LINE)
+
+	# Confirm the datamin and datamax parameters.
+	skysigma = ap_vsigma (ap)
+	datamin = ap_vdatamin (ap)
+	datamax = ap_vdatamax (ap)
+
+	call printf ("\n")
+
+	# Update the database file.
+	if (out != NULL && stid > 1) {
+	    call ap_sparam (out, KY_CSTRING, Memc[cstr], UN_CALGORITHM,
+		"centering aperture")
+	    call ap_rparam (out, KY_FWHMPSF, fwhmpsf, UN_ASCALEUNIT,
+	        "full width half maximum of the psf")
+	    call ap_rparam (out, KY_CAPERT, capert, UN_CSCALEUNIT,
+	        "centering box width")
+	    call ap_sparam (out, KY_SSTRING, Memc[sstr], UN_SALGORITHM,
+		"sky fitting algorithm")
+	    call ap_rparam (out, KY_ANNULUS, annulus, UN_SSCALEUNIT,
+	        "inner radius of the sky annulus")
+	    call ap_rparam (out, KY_DANNULUS, dannulus, UN_SSCALEUNIT,
+	        "width of the sky annulus")
+	    call ap_rparam (out, KY_SKYSIGMA, skysigma, UN_NCOUNTS,
+	        "standard deviation of 1 sky pixel")
+	    call ap_sparam (out, KY_APERTS, Memc[aperts], UN_PSCALEUNIT,
+		"list of apertures")
+	    call ap_rparam (out, KY_DATAMIN, datamin, UN_ACOUNTS,
+	        "minimum good data value")
+	    call ap_rparam (out, KY_DATAMAX, datamax, UN_ACOUNTS,
+	        "maximum good data value")
+	}
+
+	call sfree (sp)
+end
diff --git a/noao/digiphot/apphot/phot/apperrors.x b/noao/digiphot/apphot/phot/apperrors.x
new file mode 100644
index 00000000..ff67e3ee
--- /dev/null
+++ b/noao/digiphot/apphot/phot/apperrors.x
@@ -0,0 +1,48 @@
+include "../lib/phot.h"
+
+# AP_PERRORS -- Print the photometry task errors.
+
+procedure ap_perrors (ap, cier, sier, pier)
+
+pointer	ap		# apphot structure
+int	cier		# centering error code
+int	sier		# sky fitting error code
+int	pier		# photometry error code
+
+begin
+	# Print the centering error message.
+	call ap_cerrors (ap, cier)
+
+	# Print the sky fitting error message.
+	call ap_serrors (ap, sier)
+
+	# Print the photometry error message.
+	call ap_merrors (ap, pier)
+
+end
+
+
+# AP_MERRORS -- Print the photometry errors.
+
+procedure ap_merrors (ap, pier)
+
+pointer	ap			# pointer to the apphot structure (unused)
+int	pier			# photometry error
+
+begin
+	# Print the photometry error message.
+	switch (pier) {
+	case AP_APERT_NOAPERT:
+	    call printf ("Photometry apertures are outside of the image.\n")
+	case AP_APERT_OUTOFBOUNDS:
+	 call printf ("Photometry apertures are partially outside the image.\n")
+	case AP_APERT_NOSKYMODE:
+	    call printf ("The sky value is undefined.\n")
+	case AP_APERT_NEGMAG:
+	    call printf ("The total flux inside the aperture is negative.\n")
+	case AP_APERT_BADDATA:
+	    call printf ("Bad data in the aperture(s).\n")
+	default:
+	    call printf ("")
+	}
+end
diff --git a/noao/digiphot/apphot/phot/appfree.x b/noao/digiphot/apphot/phot/appfree.x
new file mode 100644
index 00000000..6d588f8a
--- /dev/null
+++ b/noao/digiphot/apphot/phot/appfree.x
@@ -0,0 +1,66 @@
+include "../lib/apphotdef.h"
+include "../lib/photdef.h"
+
+# APFREE -- Free the apphot structure.
+
+procedure appfree (ap)
+
+pointer	ap		# pointer to the apphot structure
+
+begin
+	if (ap == NULL)
+	    return
+	if (AP_NOISE(ap) != NULL)
+	    call ap_noisecls (ap)
+	if (AP_PCENTER(ap) != NULL)
+	    call ap_ctrcls (ap)
+	if (AP_PDISPLAY(ap) != NULL)
+	    call ap_dispcls (ap)
+	if (AP_POLY(ap) != NULL)
+	    call ap_ycls (ap)
+	if (AP_PPHOT(ap) != NULL)
+	    call ap_photcls (ap)
+	if (AP_PPSF(ap) != NULL)
+	    call ap_psfcls (ap)
+	if (AP_PSKY(ap) != NULL)
+	    call ap_skycls (ap)
+	if (AP_IMBUF(ap) != NULL)
+	    call mfree (AP_IMBUF(ap), TY_REAL)
+	if (AP_MW(ap) != NULL)
+	    call mw_close (AP_MW(ap))
+	call mfree (ap, TY_STRUCT)
+end
+
+
+# AP_PHOTCLS -- Procedure to close up the photometry structure and arrays.
+
+procedure ap_photcls (ap)
+
+pointer	ap		# pointer to apphot structure
+
+pointer	phot
+
+begin
+	if (AP_PPHOT(ap) == NULL)
+	    return
+	phot = AP_PPHOT(ap)
+	if (AP_APERTS(phot) != NULL)
+	    call mfree (AP_APERTS(phot), TY_REAL)
+	if (AP_MAGS(phot) != NULL)
+	    call mfree (AP_MAGS(phot), TY_REAL)
+	if (AP_MAGERRS(phot) != NULL)
+	    call mfree (AP_MAGERRS(phot), TY_REAL)
+	if  (AP_SUMS(phot) != NULL)
+	    call mfree (AP_SUMS(phot), TY_DOUBLE)
+	if (AP_AREA(phot) != NULL)
+	    call mfree (AP_AREA(phot), TY_DOUBLE)
+
+	#if (AP_APIX(phot) != NULL)
+	    #call mfree (AP_APIX(phot), TY_REAL)
+	#if (AP_XAPIX(phot) != NULL)
+	    #call mfree (AP_XAPIX(phot), TY_REAL)
+	#if (AP_YAPIX(phot) != NULL)
+	    #call mfree (AP_YAPIX(phot), TY_REAL)
+
+	call mfree (AP_PPHOT(ap), TY_STRUCT)
+end
diff --git a/noao/digiphot/apphot/phot/apphot.x b/noao/digiphot/apphot/phot/apphot.x
new file mode 100644
index 00000000..1f8b942d
--- /dev/null
+++ b/noao/digiphot/apphot/phot/apphot.x
@@ -0,0 +1,511 @@
+include <ctype.h>
+include <gset.h>
+include <imhdr.h>
+include "../lib/phot.h"
+include "../lib/apphot.h"
+include "../lib/display.h"
+include "../lib/center.h"
+include "../lib/fitsky.h"
+
+define	HELPFILE	"apphot$phot/phot.key"
+
+# APPHOT -- Procedure to compute magnitudes for a list of objects
+
+int procedure apphot (ap, im, cl, sd, gd, mgd, id, out, stid, interactive,
+	cache)
+
+pointer ap			# pointer to apphot structure
+pointer	im			# pointer to IRAF image
+int	cl			# starlist file descriptor
+int	sd			# the sky file descriptor
+pointer	gd			# pointer to graphcis descriptor
+pointer	mgd			# pointer to the metacode file
+pointer	id			# pointer to image display stream
+int	out			# output file descriptor
+int	stid			# output file sequence number
+int	interactive		# interactive mode
+int	cache			# cache the input image pixels
+
+real	wx, wy, xlist, ylist
+pointer	sp, cmd
+int	newimage, newskybuf, newsky, newcenterbuf, newcenter, newmagbuf, newmag
+int	colonkey, prev_num, req_num, ip, cier, sier, pier, oid, req_size
+int	old_size, buf_size, memstat, wcs, key, ltid, newlist
+
+real	apstatr()
+int	clgcur(), apfitsky(), aprefitsky(), apfitcenter(), aprefitcenter()
+int	apmag(), apremag(), apgscur(), ctoi(), apstati(), apgqverify()
+int	apgtverify(), apnew(), ap_avsky(), ap_memstat(), sizeof()
+bool	fp_equalr()
+
+define  endswitch_ 99
+
+begin
+	# Initialize.
+	call smark (sp)
+	call salloc (cmd, SZ_LINE, TY_CHAR)
+
+	# Initialize cursor command.
+	key = ' '
+	Memc[cmd] = EOS
+
+	# Initialize the fitting parameters.
+	newimage = NO
+	newcenterbuf = YES
+	newcenter = YES
+	newskybuf = YES
+	newsky = YES
+	newmagbuf = YES
+	newmag = YES
+	cier = AP_OK
+	sier = AP_OK
+	pier = AP_OK
+
+	# Intialize the sequencing.
+	newlist = NO
+	ltid = 0
+
+	# Loop over the coordinate file.
+	while (clgcur ("icommands", wx, wy, wcs, key, Memc[cmd], SZ_LINE) !=
+	    EOF) {
+
+	    # Store the current cursor coordinates.
+	    call ap_vtol (im, wx, wy, wx, wy, 1)
+	    call apsetr (ap, CWX, wx)
+	    call apsetr (ap, CWY, wy)
+
+	    # Test to see if the cursor moved.
+	    if (apnew (ap, wx, wy, xlist, ylist, newlist) == YES) {
+		newcenterbuf = YES
+		newcenter = YES
+		newskybuf = YES
+		newsky = YES
+		newmagbuf = YES
+		newmag = YES
+	    }
+
+	    # Store previous cursor coordinates.
+	    call apsetr (ap, WX, apstatr (ap, CWX))
+	    call apsetr (ap, WY, apstatr (ap, CWY))
+
+	    # Loop over the colon keystroke commands.
+	    switch (key) {
+
+	    # Quit.
+	    case 'q':
+		if (interactive == YES) {
+		    if (apgqverify ("phot", ap, key) == YES) {
+			call sfree (sp)
+			return (apgtverify (key))
+		    }
+		} else {
+		    call sfree (sp)
+		    return (NO)
+		}
+
+	    # Print out error messages.
+	    case 'e':
+		if (interactive == YES)
+		    call ap_perrors (ap, cier, sier, pier)
+
+	    # Print out the help page(s).
+	    case '?':
+		if ((id != NULL) && (id == gd))
+		    call gpagefile (id, HELPFILE, "")
+		else if (interactive == YES)
+		    call pagefile (HELPFILE, "[space=morehelp,q=quit,?=help]")
+
+	    # Plot a centered stellar radial profile.
+	    case 'd':
+		if (interactive == YES) {
+		    call ap_qrad (ap, im, wx, wy, gd)
+		    newmagbuf = YES; newmag = YES
+		    newcenterbuf = YES; newcenter = YES
+		    newskybuf = YES; newsky = YES
+		}
+
+	    # Rewind the list.
+	    case 'r':
+		if (cl != NULL) {
+		    call seek (cl, BOFL)
+		    ltid = 0
+		} else if (interactive == YES)
+		    call printf ("No coordinate list\n")
+
+	    # Get, measure the next object in the coordinate list.
+	    case 'm', 'n':
+
+		# No coordinate file.
+                if (cl == NULL) {
+                    if (interactive == YES)
+                        call printf ("No coordinate list\n")
+                    goto endswitch_
+
+		}
+
+		# Need to rewind coordinate file.
+		prev_num = ltid
+		req_num = ltid + 1
+		if (apgscur (cl, id, xlist, ylist, prev_num, req_num,
+		    ltid) == EOF) {
+                    if (interactive == YES)
+                        call printf (
+                            "End of coordinate list, use r key to rewind\n")
+                    goto endswitch_
+
+		}
+
+                # Convert coordinates if necessary.
+                switch (apstati (ap, WCSIN)) {
+                case WCS_PHYSICAL, WCS_WORLD:
+                    call ap_itol (ap,  xlist, ylist, xlist, ylist, 1)
+                case WCS_TV:
+                    call ap_vtol (im, xlist, ylist, xlist, ylist, 1)
+                default:
+                    ;
+                }
+
+		# Move to next object.
+		newlist = YES
+		if (key == 'm') {
+		    newcenterbuf = YES; newcenter = YES
+		    newskybuf = YES; newsky = YES
+		    newmagbuf = YES; newmag = YES
+                    goto endswitch_
+		}
+
+		# Measure next object.
+		cier = apfitcenter (ap, im, xlist, ylist)
+		sier = apfitsky (ap, im, apstatr (ap, XCENTER), apstatr (ap,
+		    YCENTER), sd, gd)
+		pier = apmag (ap, im, apstatr (ap, XCENTER), apstatr (ap,
+		    YCENTER), apstati (ap, POSITIVE), apstatr (ap, SKY_MODE),
+		    apstatr (ap, SKY_SIGMA), apstati (ap, NSKY))
+		if (id != NULL) {
+		    call apmark (ap, id, apstati (ap, MKCENTER), apstati (ap,
+			MKSKY), apstati (ap, MKAPERT))
+		    if (id == gd)
+			call gflush (id)
+		    else
+			call gframe (id)
+		}
+		call ap_pplot (ap, im, stid, gd, apstati (ap, RADPLOTS))
+		if (interactive == YES)
+		    call ap_qpmag (ap, cier, sier, pier)
+		if (stid == 1)
+		    call ap_param (ap, out, "phot")
+		call ap_pmag (ap, out, stid, ltid, cier, sier, pier)
+		call ap_pplot (ap, im, stid, mgd, YES)
+		stid = stid + 1
+		newcenterbuf = NO; newcenter = NO
+		newskybuf = NO; newsky = NO
+		newmagbuf = NO; newmag = NO
+
+	    # Process the remainder of the list.
+	    case 'l':
+		if (cl != NULL) {
+		    ltid = ltid + 1
+		    oid = stid
+		    call apbphot (ap, im, cl, sd, out, stid, ltid, gd, mgd, id,
+		        YES)
+		    ltid = ltid + stid - oid + 1
+		    if (id != NULL) {
+		        if (id == gd)
+			    call gflush (id)
+		        else
+		            call gframe (id)
+		    }
+		} else if (interactive == YES)
+		    call printf ("No coordinate list\n")
+
+	    # Process apphot colon commands.
+	    case ':':
+		for (ip = 1; IS_WHITE(Memc[cmd+ip-1]); ip = ip + 1)
+		    ;
+		colonkey = Memc[cmd+ip-1]
+		switch (colonkey) {
+		case 'm', 'n':
+
+		    # Show/set a phot parameter.
+		    if (Memc[cmd+ip] != EOS && Memc[cmd+ip] != ' ') {
+		        call apphotcolon (ap, im, cl, out, stid, ltid,
+			    Memc[cmd], newimage, newcenterbuf, newcenter,
+			    newskybuf, newsky, newmagbuf, newmag)
+			goto endswitch_
+		    }
+
+		    # No coordinate list.
+		    if (cl == NULL) {
+                        if (interactive == YES)
+                            call printf ("No coordinate list\n")
+                        goto endswitch_
+		    }
+
+		    # Get next object from the list.
+		    ip = ip + 1
+		    prev_num = ltid
+		    if (ctoi (Memc[cmd], ip, req_num) <= 0)
+		        req_num = ltid + 1
+
+		    # Fetch the next object from the list.
+		    if (apgscur (cl, id, xlist, ylist, prev_num, req_num,
+			ltid) == EOF) {
+                        if (interactive == YES)
+                            call printf (
+                            "End of coordinate list, use r key to rewind\n")
+                        goto endswitch_
+		    }
+
+                    # Convert the coordinates.
+                    switch (apstati (ap, WCSIN)) {
+                    case WCS_PHYSICAL, WCS_WORLD:
+                        call ap_itol (ap,  xlist, ylist, xlist, ylist, 1)
+                    case WCS_TV:
+                        call ap_vtol (im, xlist, ylist, xlist, ylist, 1)
+                    default:
+                        ;
+                    }
+
+		    # Move to the next object.
+		    newlist = YES
+		    if (colonkey == 'm') {
+		        newcenterbuf = YES; newcenter = YES
+		        newskybuf = YES; newsky = YES
+		        newmagbuf = YES; newmag = YES
+                        goto endswitch_
+		    }
+		    cier = apfitcenter (ap, im, xlist, ylist)
+		    sier = apfitsky (ap, im, apstatr (ap, XCENTER),
+			apstatr (ap, YCENTER), sd, gd)
+		    pier = apmag (ap, im, apstatr (ap, XCENTER), apstatr (ap,
+			YCENTER), apstati (ap, POSITIVE), apstatr (ap,
+			SKY_MODE), apstatr (ap, SKY_SIGMA), apstati (ap, NSKY))
+		    if (id != NULL) {
+		        call apmark (ap, id, apstati (ap, MKCENTER),
+			    apstati (ap, MKSKY), apstati (ap, MKAPERT))
+			if (id == gd)
+			    call gflush (id)
+			else
+			    call gframe (id)
+		    }
+		    call ap_pplot (ap, im, stid, gd, apstati (ap, RADPLOTS))
+		    if (interactive == YES)
+		        call ap_qpmag (ap, cier, sier, pier)
+		    if (stid == 1)
+		        call ap_param (ap, out, "phot")
+		    call ap_pmag (ap, out, stid, ltid, cier, sier, pier)
+		    call ap_pplot (ap, im, stid, mgd, YES)
+		    stid = stid + 1
+		    newcenterbuf = NO; newcenter = NO
+		    newskybuf = NO; newsky = NO
+		    newmagbuf = NO; newmag = NO
+
+		# Show/set a phot parameter.
+		default:
+		    call apphotcolon (ap, im, cl, out, stid, ltid, Memc[cmd],
+		        newimage, newcenterbuf, newcenter, newskybuf, newsky,
+			newmagbuf, newmag)
+		}
+
+		# Reestablish the image display viewport if necessary.
+		if (newimage == YES) {
+		    if ((id != NULL) && (id != gd))
+		        call ap_gswv (id, Memc[cmd], im, 4)
+                    req_size = MEMFUDGE * IM_LEN(im,1) * IM_LEN(im,2) *
+                        sizeof (IM_PIXTYPE(im))
+                    memstat = ap_memstat (cache, req_size, old_size)
+                    if (memstat == YES)
+                        call ap_pcache (im, INDEFI, buf_size)
+		}
+
+		newimage = NO
+
+	    # Save the current parameters in the pset files.
+	    case 'w':
+		call ap_ppars (ap)
+
+	    # Setup phot parameters interactively.
+	    case 'i':
+		if (interactive == YES) {
+		    call ap_radsetup (ap, im, wx, wy, gd, out, stid)
+		    newcenterbuf = YES; newcenter = YES
+		    newskybuf = YES; newsky = YES
+		    newmagbuf = YES; newmag = YES
+		}
+
+	    # Verify the critical PHOT parameters.
+	    case 'v':
+		call ap_pconfirm (ap, out, stid)
+		newcenterbuf = YES; newcenter = YES
+		newskybuf = YES; newsky = YES
+		newmagbuf = YES; newmag = YES
+
+	    # Fit the center around the cursor position.
+	    case 'c':
+		if (newcenterbuf == YES)
+		    cier = apfitcenter (ap, im, wx, wy)
+		else if (newcenter == YES)
+		    cier = aprefitcenter (ap, im, cier)
+		if (id != NULL) {
+		    call apmark (ap, id, apstati (ap, MKCENTER), NO, NO)
+		    if (id == gd)
+			call gflush (id)
+		    else
+		        call gframe (id)
+		}
+		call ap_cplot (ap, stid, gd, apstati (ap, RADPLOTS))
+		if (interactive == YES)
+		    call ap_qcenter (ap, cier)
+		newcenterbuf = NO; newcenter = NO
+
+	    # Fit the sky around the cursor position.
+	    case 't':
+	        if (newskybuf == YES || ! fp_equalr (wx,
+		    apstatr (ap, SXCUR)) || ! fp_equalr (wy, apstatr (ap,
+		    SYCUR)))
+		    sier = apfitsky (ap, im, wx, wy, sd, gd)
+	        else if (newsky == YES)
+		    sier = aprefitsky (ap, im, gd)
+		if (id != NULL) {
+		    call apmark (ap, id, NO, apstati (ap, MKSKY), NO)
+		    if (id == gd)
+			call gflush (id)
+		    else
+		        call gframe (id)
+		}
+		call ap_splot (ap, stid, gd, apstati (ap, RADPLOTS))
+		if (interactive == YES)
+		    call ap_qspsky (ap, sier)
+		newskybuf = NO; newsky = NO
+
+	    # Compute the average of several sky measurements around
+	    # different cursor postions.
+	    case 'a':
+		sier = ap_avsky (ap, im, stid, sd, id, gd, interactive)
+		if (interactive == YES)
+		    call ap_qaspsky (ap, sier)
+		newskybuf = NO; newsky = NO
+
+	     # Fit the sky around the current center position. 
+	     case 's':
+	        if (newskybuf == YES || ! fp_equalr (apstatr (ap, XCENTER),
+		    apstatr (ap, SXCUR)) || ! fp_equalr (apstatr (ap, SYCUR),
+		    apstatr (ap, YCENTER)))
+		    sier = apfitsky (ap, im, apstatr (ap, XCENTER),
+		        apstatr (ap, YCENTER), sd, gd)
+		else if (newsky == YES)
+		    sier = aprefitsky (ap, im, gd)
+		if (id != NULL) {
+		    call apmark (ap, id, NO, apstati (ap, MKSKY), NO)
+		    if (id == gd)
+			call gflush (id)
+		    else
+		        call gframe (id)
+		}
+		call ap_splot (ap, stid, gd, apstati (ap, RADPLOTS))
+		if (interactive == YES)
+		    call ap_qspsky (ap, sier)
+		newskybuf = NO; newsky = NO
+
+	    # Compute magnitudes around the current star using the current
+	    # sky.
+	    case 'p', 'o':
+		if (newcenterbuf == YES)
+		    cier = apfitcenter (ap, im, wx, wy)
+		else if (newcenter == YES)
+		    cier = aprefitcenter (ap, im, cier)
+	        if (newmagbuf == YES || ! fp_equalr (apstatr (ap, XCENTER),
+		    apstatr (ap, PXCUR)) || ! fp_equalr (apstatr (ap,
+		    PYCUR), apstatr (ap, YCENTER)))
+		    pier = apmag (ap, im, apstatr (ap, XCENTER), apstatr (ap,
+		        YCENTER), apstati (ap, POSITIVE), apstatr (ap,
+			SKY_MODE), apstatr (ap, SKY_SIGMA), apstati (ap, NSKY))
+		else
+		    pier = apremag (ap, im, apstati (ap, POSITIVE), apstatr (ap,
+		        SKY_MODE), apstatr (ap, SKY_SIGMA), apstati (ap, NSKY))
+		if (id != NULL) {
+		    call apmark (ap, id, NO, NO, apstati (ap, MKAPERT))
+		    if (id == gd)
+			call gflush (id)
+		    else
+		        call gframe (id)
+		}
+		if (interactive == YES)
+		    call ap_qpmag (ap, cier, sier, pier)
+		newcenterbuf = NO; newcenter = NO
+		newmagbuf = NO; newmag = NO
+
+		if (key == 'o') {
+		    if (stid == 1)
+		        call ap_param (ap, out, "phot")
+		    if (newlist == YES)
+		        call ap_pmag (ap, out, stid, ltid, cier, sier, pier)
+		    else
+		        call ap_pmag (ap, out, stid, 0, cier, sier, pier)
+		    call ap_pplot (ap, im, stid, mgd, YES)
+		    stid = stid + 1
+		}
+
+	    # Compute the center, sky, and magnitudes and save the results.
+	    case 'f', ' ':
+		if (newcenterbuf == YES)
+		    cier = apfitcenter (ap, im, wx, wy)
+		else if (newcenter == YES)
+		    cier = aprefitcenter (ap, im, cier)
+		if (newskybuf == YES || ! fp_equalr (apstatr (ap, XCENTER),
+		    apstatr (ap, SXCUR)) || ! fp_equalr (apstatr (ap, YCENTER),
+		    apstatr (ap, SYCUR)))
+		    sier = apfitsky (ap, im, apstatr (ap, XCENTER), apstatr (ap,
+		        YCENTER), sd, gd)
+		else if (newsky == YES)
+		    sier = aprefitsky (ap, im, gd)
+		if (newmagbuf == YES || ! fp_equalr (apstatr (ap, XCENTER),
+		    apstatr (ap, PXCUR)) || ! fp_equalr (apstatr (ap, YCENTER),
+		    apstatr (ap, PYCUR)))
+		    pier = apmag (ap, im, apstatr (ap, XCENTER),
+		        apstatr (ap, YCENTER), apstati (ap, POSITIVE),
+			apstatr (ap, SKY_MODE), apstatr (ap, SKY_SIGMA),
+			apstati (ap, NSKY))
+		else
+		    pier = apremag (ap, im, apstati (ap, POSITIVE), apstatr (ap,
+		        SKY_MODE), apstatr (ap, SKY_SIGMA), apstati (ap, NSKY))
+
+		if (id != NULL) {
+		    call apmark (ap, id, apstati (ap, MKCENTER), apstati (ap,
+		        MKSKY), apstati (ap, MKAPERT))
+		    if (id == gd)
+			call gflush (id)
+		    else
+		        call gframe (id)
+		}
+		call ap_pplot (ap, im, stid, gd, apstati (ap, RADPLOTS))
+		if (interactive == YES)
+		    call ap_qpmag (ap, cier, sier, pier)
+
+		newcenterbuf = NO; newcenter = NO
+		newskybuf = NO; newsky = NO
+		newmagbuf = NO; newmag = NO
+
+		if (key == ' ') {
+		    if (stid == 1)
+		        call ap_param (ap, out, "phot")
+		    if (newlist == YES)
+		        call ap_pmag (ap, out, stid, ltid, cier, sier, pier)
+		    else
+		        call ap_pmag (ap, out, stid, 0, cier, sier, pier)
+		    call ap_pplot (ap, im, stid, mgd, YES)
+		    stid = stid + 1
+		}
+
+	    default:
+		call printf ("Unknown or ambiguous keystroke command\n")
+	    }
+
+endswitch_
+	    # Setup for the next object.
+	    key = ' '
+	    Memc[cmd] = EOS
+	}
+
+	call sfree (sp)
+end
diff --git a/noao/digiphot/apphot/phot/apphotcolon.x b/noao/digiphot/apphot/phot/apphotcolon.x
new file mode 100644
index 00000000..825459b2
--- /dev/null
+++ b/noao/digiphot/apphot/phot/apphotcolon.x
@@ -0,0 +1,209 @@
+include <gset.h>
+include "../lib/apphot.h"
+include "../lib/fitsky.h"
+include "../lib/center.h"
+include "../lib/phot.h"
+include "../lib/display.h"
+include "../lib/noise.h"
+
+# APPHOTCOLON -- Process phot colon commands.
+
+procedure apphotcolon (ap, im, cl, out, stid, ltid, cmdstr, newimage,
+	newcenterbuf, newcenter, newskybuf, newsky, newmagbuf, newmag)
+
+pointer	ap				# pointer to the apphot structure
+pointer	im				# pointer to the iraf image
+int	cl				# coord file descriptor
+int	out				# output file descriptor
+int	stid				# output file sequence number
+int	ltid				# coord list sequence number
+char	cmdstr[ARB]			# command string
+int	newimage			# new image ?
+int	newcenterbuf, newcenter		# new center buffer ? new center fit ?
+int	newskybuf, newsky		# new sky buffer ? new sky fit ?
+int	newmagbuf, newmag		# new aperture buffer ? new fit ?
+
+pointer	sp, incmd, outcmd
+int	strdic()
+
+begin
+	call smark (sp)
+	call salloc (incmd, SZ_LINE, TY_CHAR)
+	call salloc (outcmd, SZ_LINE, TY_CHAR)
+
+	# Get the command.
+	call sscan (cmdstr)
+	call gargwrd (Memc[incmd], SZ_LINE)
+	if (Memc[incmd] == EOS) {
+	    call sfree (sp)
+	    return
+	}
+
+	# Process the command.
+	if (strdic (Memc[incmd], Memc[outcmd], SZ_LINE, CCMDS) != 0)
+	    call apccolon (ap, out, stid, cmdstr, newcenterbuf, newcenter)
+	else if (strdic (Memc[incmd], Memc[outcmd], SZ_LINE, SCMDS) != 0)
+	    call apscolon (ap, out, stid, cmdstr, newskybuf, newsky)
+	else if (strdic (Memc[incmd], Memc[outcmd], SZ_LINE, PCMDS) != 0)
+	    call apmagcolon (ap, out, stid, cmdstr, newmagbuf, newmag)
+	else if (strdic (Memc[incmd], Memc[outcmd], SZ_LINE, APCMDS) != 0)
+	    call ap_apcolon (ap, im, cl, out, stid, ltid, cmdstr, newimage,
+	        newcenterbuf, newcenter, newskybuf, newsky, newmagbuf, newmag)
+	else if (strdic (Memc[incmd], Memc[outcmd], SZ_LINE, NCMDS) != 0)
+	    call apnscolon (ap, im, out, stid, cmdstr, newcenterbuf,
+	        newcenter, newskybuf, newsky, newmagbuf, newmag)
+	else
+	    call ap_himcolon (ap, cmdstr)
+
+	call sfree (sp)
+end
+
+
+# APMAGCOLON -- Procedure to display and edit the photometry parameters.
+
+procedure apmagcolon (ap, out, stid, cmdstr, newmagbuf, newmag)
+
+pointer	ap		# pointer to apphot structure
+int	out		# output file descriptor
+int	stid		# output number
+char	cmdstr[ARB]	# command string
+int	newmagbuf	# new aperture buffers
+int	newmag		# compute new magnitudes
+
+bool	bval
+int	ncmd
+pointer	sp, cmd
+real	rval
+bool	itob()
+int	btoi(), strdic(), nscan(), apstati()
+real	apstatr()
+
+begin
+	# Get the command.
+	call smark (sp)
+	call salloc (cmd, SZ_LINE, TY_CHAR)
+
+	call sscan (cmdstr)
+	call gargwrd (Memc[cmd], SZ_LINE)
+	if (Memc[cmd] == EOS) {
+	    call sfree (sp)
+	    return
+	}
+
+	# Process the command
+	ncmd = strdic (Memc[cmd], Memc[cmd], SZ_LINE, PCMDS)
+	switch (ncmd) {
+	case PCMD_APERTURES:
+	    call gargwrd (Memc[cmd], SZ_LINE)
+	    if (Memc[cmd] == EOS) {
+	        call apstats (ap, APERTS, Memc[cmd], SZ_LINE)
+	        call printf ("%s = %s %s\n")
+		    call pargstr (KY_APERTS)
+		    call pargstr (Memc[cmd])
+		    call pargstr (UN_PSCALEUNIT)
+	    } else {
+		call apsets (ap, APERTS, Memc[cmd])
+		if (stid > 1)
+		    call ap_sparam (out, KY_APERTS, Memc[cmd], UN_PSCALEUNIT,
+			"list of aperture radii")
+		newmag = YES
+		newmagbuf = YES
+	    }
+	case PCMD_ZMAG:
+	    call gargr (rval)
+	    if (nscan() == 1) {
+		call printf ("%s = %g\n")
+		    call pargstr (KY_ZMAG)
+		    call pargr (apstatr (ap, ZMAG))
+	    } else {
+		call apsetr (ap, ZMAG, rval)
+		if (stid > 1)
+		    call ap_rparam (out, KY_ZMAG, rval, UN_PZMAG,
+			"zero point of magnitude scale")
+		newmag = YES
+	    }
+	case PCMD_MKAPERT:
+	    call gargb (bval)
+	    if (nscan () == 1) {
+		call printf ("%s = %b\n")
+		    call pargstr (KY_MKAPERT)
+		    call pargb (itob (apstati (ap, MKAPERT)))
+	    } else {
+		call apseti (ap, MKAPERT, btoi (bval))
+	    }
+	default:
+	    call printf ("Unknown command\7\n")
+	}
+
+	call sfree (sp)
+end
+
+
+# AP_HIMCOLON -- Procedure to process commands which alter the centering, sky
+# fitting and photometry buffers.
+
+procedure ap_himcolon (ap, cmdstr)
+
+pointer	ap			# pointer to the apphot structure
+char	cmdstr[ARB]		# command string
+
+bool	bval
+int	ncmd
+pointer	sp, cmd
+bool	itob()
+int	strdic(), nscan(), btoi(), apstati()
+
+begin
+	call smark (sp)
+	call salloc (cmd, SZ_LINE, TY_CHAR)
+
+	# Get the command.
+	call sscan (cmdstr)
+	    call gargwrd (Memc[cmd], SZ_LINE)
+	if (Memc[cmd] == EOS) {
+	    call sfree (sp)
+	    return
+	}
+
+	# Process the command.
+	ncmd = strdic (Memc[cmd], Memc[cmd], SZ_LINE, MISC)
+	switch (ncmd) {
+	case ACMD_SHOW:
+	    call gargwrd (Memc[cmd], SZ_LINE)
+	    ncmd = strdic (Memc[cmd], Memc[cmd], SZ_LINE, PSHOWARGS)
+	    switch (ncmd) {
+	    case PCMD_CENTER:
+		call printf ("\n")
+		call ap_cpshow (ap)
+		call printf ("\n")
+	    case PCMD_SKY:
+		call printf ("\n")
+		call ap_spshow (ap)
+		call printf ("\n")
+	    case PCMD_PHOT:
+		call printf ("\n")
+		call ap_mpshow (ap)
+		call printf ("\n")
+	    case PCMD_DATA:
+		call printf ("\n")
+		call ap_nshow (ap)
+		call printf ("\n")
+	    default:
+		call printf ("\n")
+		call ap_pshow (ap)
+		call printf ("\n")
+	    }
+	case ACMD_RADPLOTS:
+	    call gargb (bval)
+	    if (nscan () == 1) {
+		call printf ("%s = %b\n")
+		    call pargstr (KY_RADPLOTS)
+		    call pargb (itob (apstati (ap, RADPLOTS)))
+	    } else
+		call apseti (ap, RADPLOTS, btoi (bval))
+	default:
+	    call printf ("Unknown or ambigous colon command\7\n")
+	}
+
+	call sfree (sp)
+end
diff --git a/noao/digiphot/apphot/phot/appinit.x b/noao/digiphot/apphot/phot/appinit.x
new file mode 100644
index 00000000..b9f558c2
--- /dev/null
+++ b/noao/digiphot/apphot/phot/appinit.x
@@ -0,0 +1,100 @@
+include "../lib/apphotdef.h"
+include "../lib/photdef.h"
+include "../lib/phot.h"
+
+# APPINIT - Procedure to initialize apphot structure.
+
+procedure appinit (ap, cfunction, cbox, sfunction, annulus, dannulus,
+        aperts, napert, weight, fwhmpsf, noise)
+
+pointer	ap		# pointer to the apphot structure
+int	cfunction	# centering algorithm
+real	cbox		# half width of the centering box
+int	sfunction	# sky fitting algorithm
+real	annulus		# radius of sky annulus
+real	dannulus	# width of sky annulus
+real	aperts[ARB]	# apertures
+int	napert		# number of apertures
+int	weight		# weight for photometry
+real	fwhmpsf		# FWHM of the PSF
+int	noise		# noise model
+
+begin
+	# Set the image parameters.
+	call malloc (ap, LEN_APSTRUCT, TY_STRUCT)
+
+	# Set up the apphot package defaults.
+	call ap_defsetup (ap, fwhmpsf)
+
+	# Set up noise structure.
+	call ap_noisesetup (ap, noise)
+
+	# Set up centering structure.
+	call ap_ctrsetup (ap, cfunction, cbox)
+
+	# Set up sky fitting structure.
+	call ap_skysetup (ap, sfunction, annulus, dannulus)
+
+	# Set up photometry structure.
+	call ap_photsetup (ap, aperts, napert, weight)
+	    
+	# Set the display options.
+	call ap_dispsetup (ap)
+
+	# Unused structures are set to null.
+	AP_PPSF(ap) = NULL
+	AP_POLY(ap) = NULL
+	AP_RPROF(ap) = NULL
+end
+
+
+# AP_PHOTSETUP -- Procedure to set up the photometry parameters.
+
+procedure ap_photsetup (ap, aperts, napert, weight)
+
+pointer	ap		# pointer to apphot structure
+real	aperts[ARB]	# array of apertures
+int	napert		# number of apertures
+int	weight		# weighting function for photometry
+
+pointer	phot
+
+begin
+	# phot structure
+	call malloc (AP_PPHOT(ap), LEN_PHOTSTRUCT, TY_STRUCT)
+	phot = AP_PPHOT(ap)
+
+	# Set the default values forthe photometry parameters.
+	AP_PXCUR(phot) = INDEFR
+	AP_PYCUR(phot) = INDEFR
+	AP_NAPERTS(phot) = napert
+	AP_ZMAG(phot) = DEF_ZMAG
+	AP_PWEIGHTS(phot) = weight
+	AP_APSTRING(phot) = EOS
+	switch (weight) {
+	case AP_PWCONSTANT:
+	    call strcpy ("constant", AP_PWSTRING(phot), SZ_FNAME)
+	case AP_PWCONE:
+	    call strcpy ("cone", AP_PWSTRING(phot), SZ_FNAME)
+	case AP_PWGAUSS:
+	    call strcpy ("gauss", AP_PWSTRING(phot), SZ_FNAME)
+	default:
+	    call strcpy ("constant", AP_PWSTRING(phot), SZ_FNAME)
+	}
+
+	# Initialize buffers.
+	AP_LENABUF(phot) = 0
+	AP_NAPIX(phot) = 0
+	AP_APIX(phot) = NULL
+	AP_XAPIX(phot) = NULL
+	AP_YAPIX(phot) = NULL
+
+	# Allocate the buffers to hold the answers.
+	call malloc (AP_APERTS(phot), napert, TY_REAL)
+	call malloc (AP_MAGS(phot), napert, TY_REAL)
+	call malloc (AP_MAGERRS(phot), napert, TY_REAL)
+	call malloc (AP_AREA(phot), napert, TY_DOUBLE)
+	call malloc (AP_SUMS(phot), napert, TY_DOUBLE)
+	call amovr (aperts, Memr[AP_APERTS(phot)], napert)
+	call asrtr (Memr[AP_APERTS(phot)], Memr[AP_APERTS(phot)], napert)
+end
diff --git a/noao/digiphot/apphot/phot/appmag.x b/noao/digiphot/apphot/phot/appmag.x
new file mode 100644
index 00000000..9bc7e43c
--- /dev/null
+++ b/noao/digiphot/apphot/phot/appmag.x
@@ -0,0 +1,120 @@
+include "../lib/apphotdef.h"
+include "../lib/apphot.h"
+include "../lib/center.h"
+include "../lib/fitsky.h"
+include "../lib/photdef.h"
+include "../lib/phot.h"
+
+# AP_PMAG -- Procedure to write the results of the phot task to the output 
+# file.
+
+procedure ap_pmag (ap, fd, id, lid, cier, sier, pier)
+
+pointer	ap	# pointer to apphot structure
+int 	fd	# output text file
+int	id	# id number of str
+int	lid	# list id of star
+int	cier	# centering error
+int	sier	# sky fitting error
+int	pier	# photometric error
+
+int	i, naperts
+int	apstati()
+real	apstatr()
+
+begin
+	# Initialize.
+	if (fd == NULL)
+	    return
+
+	# Write out the object id parameters.
+	call ap_wid (ap, fd, apstatr (ap, OXINIT), apstatr(ap, OYINIT),
+	    id, lid, '\\')
+
+	# Write out the centering results.
+	call ap_wcres (ap, fd, cier, '\\')
+
+	# Write out the sky fitting results.
+	call ap_wsres (ap, fd, sier, '\\')
+
+	# Write out the photometry results.
+	naperts = apstati (ap, NAPERTS)
+	if (naperts == 0)
+	    call ap_wmres (ap, fd, 0, pier, "  ")
+	else {
+	    do i = 1, naperts {
+	        if (naperts == 1)
+		    call ap_wmres (ap, fd, i, pier, "  ")
+	        else if (i == naperts)
+		    call ap_wmres (ap, fd, i, pier, "* ")
+	        else
+		    call ap_wmres (ap, fd, i, pier, "*\\")
+	    }
+	}
+end
+
+
+# AP_QPMAG -- Procedure to print a quick summary of the phot output on the
+# standard output.
+
+procedure ap_qpmag (ap, cier, sier, pier)
+
+pointer	ap	# pointer to apphot structure
+int	cier	# centering error
+int	sier	# sky fitting error
+int	pier	# photometry error
+
+int	i
+pointer	sp, imname, phot
+real	apstatr()
+
+begin
+	# Initialize.
+	call smark (sp)
+	call salloc (imname, SZ_FNAME, TY_CHAR)
+	phot = AP_PPHOT(ap)
+
+	# Print the center and sky value.
+	call apstats (ap, IMROOT, Memc[imname], SZ_FNAME)
+	call printf ("%s  %8.2f %8.2f  %8g  ")
+	    call pargstr (Memc[imname])
+	    call pargr (apstatr (ap, OPXCUR))
+	    call pargr (apstatr (ap, OPYCUR))
+	    call pargr (apstatr (ap, SKY_MODE))
+
+	# Print out the magnitudes and errors.
+	do i = 1, AP_NAPERTS(phot) {
+	    if (i == AP_NAPERTS(phot))
+		call printf ("%7.3f  ")
+	    else
+	        call printf ("%7.3f  ")
+		call pargr (Memr[AP_MAGS(phot)+i-1])
+	}
+
+	# Print out the error codes.
+	if (cier != AP_OK || sier != AP_OK || pier != AP_OK) {
+	    call printf ("err\n")
+	} else {
+	    call printf ("ok\n")
+	}
+
+	call sfree (sp)
+end
+
+
+# AP_MAGHDR -- Procedure to print the banner for the phot task on the
+# standard output.
+
+procedure ap_maghdr (ap, fd)
+
+pointer	ap		# pointer to apphot strucuture
+int	fd		# output file descriptor
+
+begin
+	if (fd == NULL)
+	    return
+	call ap_idhdr (ap, fd)
+	call ap_chdr (ap, fd)
+	call ap_shdr (ap, fd)
+	call ap_mhdr (ap, fd)
+end
diff --git a/noao/digiphot/apphot/phot/apppars.x b/noao/digiphot/apphot/phot/apppars.x
new file mode 100644
index 00000000..68e08aeb
--- /dev/null
+++ b/noao/digiphot/apphot/phot/apppars.x
@@ -0,0 +1,26 @@
+include "../lib/display.h"
+
+# AP_PPARS -- Procedure to write out the phot task parameters.
+
+procedure ap_ppars (ap)
+
+pointer	ap		# pointer to apphot structure
+
+bool	itob()
+int	apstati()
+
+begin
+	# Write the data dependent parameters.
+	call ap_dapars (ap)
+
+	# Write the centering  parameters.
+	call ap_cepars (ap)
+
+	# Write the sky fitting paameters.
+	call ap_sapars (ap)
+
+	# Write the photometry parameters.
+	call ap_phpars (ap)
+
+	call clputb ("radplots", itob (apstati (ap, RADPLOTS)))
+end
diff --git a/noao/digiphot/apphot/phot/appplot.x b/noao/digiphot/apphot/phot/appplot.x
new file mode 100644
index 00000000..5172533d
--- /dev/null
+++ b/noao/digiphot/apphot/phot/appplot.x
@@ -0,0 +1,273 @@
+include <pkg/gtools.h>
+include <gset.h>
+include "../lib/apphot.h"
+include "../lib/noise.h"
+include "../lib/center.h"
+include "../lib/fitsky.h"
+include "../lib/phot.h"
+
+# AP_PPLOT -- Procedure to compute radial profile plots for the centering
+# routine.
+
+procedure ap_pplot (ap, im, sid, gd, makeplot)
+
+pointer	ap		# pointer to the apphot structure
+pointer	im		# pointer to the iraf image
+int	sid		# id number of the star
+pointer	gd		# graphics stream
+int	makeplot	# make a plot ?
+
+int	apert, nx, ny
+pointer	buf, sp, str, r, gt
+real	xcenter, ycenter, xc, yc, rmin, rmax, imin, imax
+real	u1, u2, v1, v2, x1, x2, y1, y2
+int	ap_ctrpix()
+pointer	ap_gtinit()
+real	apstatr()
+
+begin
+	# Initialize
+	if (gd == NULL || makeplot == NO)
+	    return
+
+	# Check for defined center and get the pixels.
+	xcenter = apstatr (ap, XCENTER)
+	ycenter = apstatr (ap, YCENTER)
+	if (IS_INDEFR(xcenter) || IS_INDEFR(ycenter))
+	    return
+
+	# Fetch the pixels.
+	apert = 2 * int (apstatr (ap, SCALE) * (apstatr (ap, ANNULUS) +
+	    apstatr (ap, DANNULUS))) + 1
+	buf = ap_ctrpix (im, xcenter, ycenter, apert, xc, yc, nx, ny)
+	if (buf == NULL)
+	    return
+
+	# Reactivate the work station.
+	call greactivate (gd, 0)
+
+	# Allocate working space.
+	call smark (sp)
+	call salloc (str, SZ_LINE, TY_CHAR)
+	call salloc (r, nx * ny, TY_REAL)
+
+	# Compute the radii and the plot limits.
+	call ap_ijtor2 (Memr[r], nx, ny, xc, yc)
+	call alimr (Memr[r], nx * ny, rmin, rmax)
+	call alimr (Memr[buf], nx * ny, imin, imax)
+
+	# Store the viewport and window coordinates.
+	call ggview (gd, u1, u2, v1, v2)
+	call ggwind (gd, x1, x2, y1, y2)
+
+	# Initialize the plot.
+	call apstats (ap, IMROOT, Memc[str], SZ_LINE)
+	call sprintf (Memc[str], SZ_LINE, "%s  Star %d")
+	    call pargstr (Memc[str])
+	    call pargi (sid)
+	gt = ap_gtinit (Memc[str], apstatr (ap, OXINIT), apstatr (ap, OYINIT))
+	call gclear (gd)
+
+	# Label and annotate the plot.
+	call ap_ppset (gd, gt, ap, rmin, rmax, imin, imax)
+	call ap_ppannotate (gd, ap, rmin, rmax, imin, imax)
+
+	# Plot the coordinates.
+	call ap_plotrad (gd, gt, Memr[r], Memr[buf], nx * ny, "plus")
+
+	# Store the viewport and window coordinates.
+	call gsview (gd, u1, u2, v1, v2)
+	call gswind (gd, x1, x2, y1, y2)
+
+	call ap_gtfree (gt)
+	call gdeactivate (gd, 0)
+	call sfree (sp)
+end
+
+
+# AP_PPSET -- Procedure to set up the parameters for the phot radial profile
+# plot.
+
+procedure ap_ppset (gd, gt, ap, xmin, xmax, ymin, ymax)
+
+pointer	gd		# the graphics stream
+pointer	gt		# the gtools pointer
+pointer	ap		# the apphot pointer
+real	xmin, xmax	# the minimum and maximum radial distance
+real	ymin, ymax	# the minimum and maximum of the y axes
+
+int	fd, naperts
+pointer	sp, str, title, temp
+real	aspect, scale, vx1, vx2, vy1, vy2
+int	stropen(), apstati()
+real	apstatr(), gstatr()
+
+begin
+	call smark (sp)
+	call salloc (str, 5 * SZ_LINE, TY_CHAR)
+	call salloc (title, SZ_LINE, TY_CHAR)
+	naperts = apstati (ap, NAPERTS)
+	call salloc (temp, naperts, TY_REAL)
+
+	fd = stropen (Memc[str], 5 * SZ_LINE, WRITE_ONLY)
+	call sysid (Memc[title], SZ_LINE)
+	call fprintf (fd, "%s\n")
+	    call pargstr (Memc[title])
+
+	# Encode the center parameter string.
+	call fprintf (fd,
+	    "Center: xc=%0.2f yc=%0.2f xerr=%0.2f yerr=%0.2f\n")
+	    call pargr (apstatr (ap, OXCENTER))
+	    call pargr (apstatr (ap, OYCENTER))
+	    call pargr (apstatr (ap, XERR))
+	    call pargr (apstatr (ap, YERR))
+
+	# Encode the sky fitting parameter string
+	call fprintf (fd,
+	    "Sky: value=%0.2f sigma=%0.2f skew=%0.2f nsky=%d nrej=%d\n")
+	    call pargr (apstatr (ap, SKY_MODE))
+	    call pargr (apstatr (ap, SKY_SIGMA))
+	    call pargr (apstatr (ap, SKY_SKEW))
+	    call pargi (apstati (ap, NSKY))
+	    call pargi (apstati (ap, NSKY_REJECT))
+
+	# Encode the apertures and magnitudes.
+	call ap_arrayr (ap, APERTS, Memr[temp])
+	call amulkr (Memr[temp], apstatr (ap, SCALE), Memr[temp], naperts)
+	call fprintf (fd, "Photometry: maxapert=")
+	call fprintf (fd, "%0.2f  mag=")
+	    call pargr (Memr[temp+naperts-1])
+	call ap_arrayr (ap, MAGS, Memr[temp])
+	call fprintf (fd, "%0.3f  merr=")
+	    call pargr (Memr[temp+naperts-1])
+	call ap_arrayr (ap, MAGERRS, Memr[temp])
+	call fprintf (fd, "%0.3f\n")
+	    call pargr (Memr[temp+naperts-1])
+
+	# Encode the title.
+	call gt_gets (gt, GTTITLE, Memc[title], SZ_LINE)
+	call fprintf (fd, "%s\n")
+	    call pargstr (Memc[title])
+
+	call strclose (fd)
+
+	aspect = gstatr (gd, G_ASPECT)
+	call gsetr (gd, G_ASPECT, 0.70)
+	scale = apstatr (ap, SCALE)
+
+	# Draw three axes.
+	call gseti (gd, G_XDRAWAXES, 2)
+	call gswind (gd, xmin / scale, xmax / scale, ymin, ymax)
+	call glabax (gd, Memc[str], "", "Intensity")
+
+	# Draw the bottom x axis.
+	call gseti (gd, G_YDRAWAXES, 0)
+	call gseti (gd, G_XDRAWAXES, 1)
+	call ggview (gd, vx1, vx2, vy1, vy2)
+	call gsview (gd, vx1, vx2, vy1, vy2)
+	call gswind (gd, xmin, xmax, ymin, ymax)
+	call glabax (gd,
+	    "","Radial Distance (lower-pixels, upper-scale units)", "")
+
+	# Restore the default draw axis parameters.
+	call gseti (gd, G_YDRAWAXES, 3)
+	call gseti (gd, G_XDRAWAXES, 3)
+	call gsetr (gd, G_ASPECT, aspect)
+
+	# Set the mark type.
+	call gt_sets (gt, GTTYPE, "mark")
+
+	call sfree (sp)
+end
+
+
+# AP_PPANNOTATE -- Procedure to annotate the radial plot in phot.
+
+procedure ap_ppannotate (gd, ap, xmin, xmax, ymin, ymax)
+
+pointer	gd		# graphics stream
+pointer	ap		# apphot structure
+real	xmin, xmax	# minimum and maximum of the x axis
+real	ymin, ymax	# minimum and maximum of the y axis
+
+int	i, naperts
+pointer	sp, str, temp
+real	annulus, dannulus, skyval, skysigma
+int	apstati()
+real	apstatr ()
+
+begin
+	naperts = apstati (ap, NAPERTS)
+	call smark (sp)
+	call salloc (str, SZ_LINE + 1, TY_CHAR)
+	call salloc (temp, naperts, TY_REAL)
+
+	# Define some temporary variables
+	annulus = apstatr (ap, SCALE) * apstatr (ap, ANNULUS)
+	dannulus = annulus + apstatr (ap, SCALE) * apstatr (ap, DANNULUS)
+
+	# Mark the inner sky annulus.
+	if (annulus >= xmin && annulus <= xmax) {
+	    call gamove (gd, annulus, ymin)
+	    call gadraw (gd, annulus, ymax)
+	    call sprintf (Memc[str], SZ_LINE, "inner sky radius = %0.2f")
+		call pargr (annulus)
+	    call gtext (gd, annulus, ymax, Memc[str], "q=h;u=180;v=t;p=r")
+	}
+     
+	# Mark the outer sky annulus.
+	if (dannulus >= xmin && dannulus <= xmax) {
+	    call gamove (gd, dannulus, ymin)
+	    call gadraw (gd, dannulus, ymax)
+	    call sprintf (Memc[str], SZ_LINE, "outer sky radius = %0.2f")
+	        call pargr (dannulus)
+	    call gtext (gd, dannulus, ymax, Memc[str], "q=h;u=180;v=t;p=r")
+	}
+
+	# Mark the sky value.
+	call gseti (gd, G_PLTYPE, GL_SOLID)
+	skyval = apstatr (ap, SKY_MODE)
+	if (skyval >= ymin && skyval <= ymax) {
+	    call gamove (gd, xmin, skyval)
+	    call gadraw (gd, xmax, skyval)
+	}
+
+	# Mark the upper sky sigma.
+	call gseti (gd, G_PLTYPE, GL_DASHED)
+	if (! IS_INDEFR(apstatr (ap, SKY_SIGMA)))
+	    skysigma = skyval + apstatr (ap, SHIREJECT) * apstatr (ap,
+	        SKY_SIGMA)
+	else
+	    skysigma = INDEFR
+	if (! IS_INDEFR(skysigma) && (skysigma >= ymin) && skysigma <= ymax) {
+	    call gamove (gd, xmin, skysigma)
+	    call gadraw (gd, xmax, skysigma)
+	}
+
+	# Mark the lower sky sigma
+	if (! IS_INDEFR(apstatr (ap, SKY_SIGMA)))
+	    skysigma = skyval - apstatr (ap, SLOREJECT) * apstatr (ap,
+	        SKY_SIGMA)
+	else
+	    skysigma = INDEFR
+	if (! IS_INDEFR(skysigma) && (skysigma >= ymin) && skysigma <= ymax) {
+	    call gamove (gd, xmin, skysigma)
+	    call gadraw (gd, xmax, skysigma)
+	}
+
+	# Mark the appertures.
+	call gseti (gd, G_PLTYPE, GL_SOLID)
+	call ap_arrayr (ap, APERTS, Memr[temp])
+	call amulkr (Memr[temp], apstatr (ap, SCALE), Memr[temp], naperts)
+	do i = 1, naperts {
+	    call gamove (gd, Memr[temp+i-1], ymin)
+	    call gadraw (gd, Memr[temp+i-1], ymax)
+	    call sprintf (Memc[str], SZ_LINE, "apert[%d] = %0.2f")
+		call pargi (i)
+		call pargr (Memr[temp+i-1])
+	    call gtext (gd, Memr[temp+i-1], ymax, Memc[str],
+	        "q=h;u=180;v=t;p=r")
+	}
+
+	call sfree (sp)
+end
diff --git a/noao/digiphot/apphot/phot/appshow.x b/noao/digiphot/apphot/phot/appshow.x
new file mode 100644
index 00000000..5e52b42d
--- /dev/null
+++ b/noao/digiphot/apphot/phot/appshow.x
@@ -0,0 +1,83 @@
+include "../lib/display.h"
+include "../lib/phot.h"
+
+# AP_PSHOW -- Procedure to print the photometry parameters.
+
+procedure ap_pshow (ap)
+
+pointer	ap	# pointer to the apphot strucuture
+
+bool	itob()
+int	apstati()
+
+begin
+	call ap_nshow (ap)
+	call printf ("\n")
+	call ap_cpshow (ap)
+	call printf ("\n")
+	call ap_spshow (ap)
+	call printf ("\n")
+	call ap_mpshow (ap)
+	call printf ("    %s = %b\n")
+	    call pargstr (KY_RADPLOTS)
+	    call pargb (itob (apstati (ap, RADPLOTS)))
+end
+
+
+# AP_MSHOW -- Procedure to print the photometry parameters on the standard
+# output.
+
+procedure ap_mshow (ap)
+
+pointer	ap		# pointer to apphot structure
+
+bool	itob()
+int	apstati()
+begin
+	call ap_nshow (ap)
+	call printf ("\n")
+	call ap_mpshow (ap)
+	call printf ("    %s = %b\n")
+	    call pargstr (KY_RADPLOTS)
+	    call pargb (itob (apstati (ap, RADPLOTS)))
+end
+
+
+# AP_MPSHOW -- Procedure to print the photometry parameters on the standard
+# output.
+
+procedure ap_mpshow (ap)
+
+pointer	ap		# pointer to apphot structure
+
+pointer	sp, str
+bool	itob()
+int	apstati()
+real	apstatr()
+
+begin
+	# Write out the image and cursor position.
+	call smark (sp)
+	call salloc (str, SZ_LINE, TY_CHAR)
+
+	# Write out the phot parameters.
+	call printf ("Photometry Parameters\n")
+	call apstats (ap, PWSTRING, Memc[str], SZ_LINE)
+	call printf ("    %s = %s %s\n")
+	    call pargstr (KY_PWSTRING)
+	    call pargstr (Memc[str])
+	    call pargstr (UN_PMODEL)
+	call apstats (ap, APERTS, Memc[str], SZ_LINE)
+	call printf ("    %s = %s %s\n")
+	    call pargstr (KY_APERTS)
+	    call pargstr (Memc[str])
+	    call pargstr (UN_PSCALEUNIT)
+	call printf ("    %s = %g\n")
+	    call pargstr (KY_ZMAG)
+	    call pargr (apstatr (ap, ZMAG))
+	call printf ("    %s = %b\n")
+	    call pargstr (KY_MKAPERT)
+	    call pargb (itob (apstati (ap, MKAPERT)))
+
+	call sfree (sp)
+end
diff --git a/noao/digiphot/apphot/phot/apqcolon.x b/noao/digiphot/apphot/phot/apqcolon.x
new file mode 100644
index 00000000..c3050190
--- /dev/null
+++ b/noao/digiphot/apphot/phot/apqcolon.x
@@ -0,0 +1,331 @@
+include <error.h>
+include "../lib/apphot.h"
+include "../lib/display.h"
+include "../lib/noise.h"
+include "../lib/center.h"
+include "../lib/fitsky.h"
+include "../lib/phot.h"
+
+# APQCOLON -- Procedure to display and edit the quick photometry parameters.
+
+procedure apqcolon (ap, im, cl, out, stid, ltid, cmdstr, newimage, newcbuf,
+	newcenter, newsbuf, newsky, newmagbuf, newmag)
+
+pointer	ap		# pointer to apphot structure
+pointer	im		# pointer to the iraf image
+int	cl		# coordinate file descriptor
+int	out		# output file descriptor
+int	stid		# output file sequence number
+int	ltid		# coordinate file sequence number
+char	cmdstr[ARB]	# command string
+int	newimage	# new image ?
+int	newcbuf		# new centering buffers ?
+int	newcenter	# compute new center ?
+int	newsbuf		# new sky fitting buffers ?
+int	newsky		# compute new sky ?
+int	newmagbuf	# new aperture buffers ?
+int	newmag		# compute new magnitudes ?
+
+bool	bval
+int	ip, ncmd
+pointer	sp, cmd, str
+real	rval
+
+bool	streq(), itob()
+int	btoi(), strdic(), nscan(), apstati(), ctowrd(), open()
+pointer	immap()
+real	apstatr()
+errchk	immap, open
+
+begin
+	# Allocate temporary space.
+	call smark (sp)
+	call salloc (cmd, SZ_LINE, TY_CHAR)
+	call salloc (str, SZ_LINE, TY_CHAR)
+
+	# Get the command.
+	call sscan (cmdstr)
+	call gargwrd (Memc[cmd], SZ_LINE)
+	if (Memc[cmd] == EOS) {
+	    call sfree (sp)
+	    return
+	}
+
+	# Process the command
+	ncmd = strdic (Memc[cmd], Memc[cmd], SZ_LINE, QCMDS)
+	switch (ncmd) {
+	case QCMD_SHOW:
+	    call printf ("\n")
+	    call ap_qshow (ap)
+	    call printf ("\n")
+
+	case QCMD_CBOXWIDTH:
+	    call gargr (rval)
+	    if (nscan() == 1) {
+		call printf ("%s = %g %s\n")
+		    call pargstr (KY_CAPERT)
+		    call pargr (2.0 * apstatr (ap, CAPERT))
+		    call pargstr ("pixels")
+	    } else {
+		call apsetr (ap, CAPERT, rval / 2.0)
+		if (stid > 1)
+		    call ap_rparam (out, KY_CAPERT, rval, UN_CSCALEUNIT,
+			"width of the centering box")
+		newcbuf = YES
+		newcenter = YES
+	    }
+
+	case QCMD_ANNULUS:
+	    call gargr (rval)
+	    if (nscan() == 1) {
+		call printf ("%s = %g %s\n")
+		    call pargstr (KY_ANNULUS)
+		    call pargr (apstatr (ap, ANNULUS))
+		    call pargstr ("pixels")
+	    } else {
+		call apsetr (ap, ANNULUS, rval)
+		if (stid > 1)
+		    call ap_rparam (out, KY_ANNULUS, rval, UN_SSCALEUNIT,
+			"inner radius of the sky annulus")
+		newsbuf = YES
+		newsky = YES
+	    }
+
+	case QCMD_DANNULUS:
+	    call gargr (rval)
+	    if (nscan() == 1) {
+		call printf ("%s = %g %s\n")
+		    call pargstr (KY_DANNULUS)
+		    call pargr (apstatr (ap, DANNULUS))
+		    call pargstr ("pixels")
+	    } else {
+		call apsetr (ap, DANNULUS, rval)
+		if (stid > 1)
+		    call ap_rparam (out, KY_DANNULUS, rval, UN_SSCALEUNIT,
+			"width of the sky annulus")
+		newsbuf = YES
+		newsky = YES
+	    }
+
+	case QCMD_APERTURES:
+	    call gargwrd (Memc[cmd], SZ_LINE)
+	    if (Memc[cmd] == EOS) {
+	        call apstats (ap, APERTS, Memc[cmd], SZ_LINE)
+	        call printf ("%s = %s %s\n")
+		    call pargstr (KY_APERTS)
+		    call pargstr (Memc[cmd])
+		    call pargstr ("pixels")
+	    } else {
+		call apsets (ap, APERTS, Memc[cmd])
+		if (stid > 1)
+		    call ap_sparam (out, KY_APERTS, Memc[cmd], UN_PSCALEUNIT,
+			"list of aperture radii")
+		newmag = YES
+		newmagbuf = YES
+	    }
+
+	case QCMD_ZMAG:
+	    call gargr (rval)
+	    if (nscan() == 1) {
+		call printf ("%s = %g\n")
+		    call pargstr (KY_ZMAG)
+		    call pargr (apstatr (ap, ZMAG))
+	    } else {
+		call apsetr (ap, ZMAG, rval)
+		if (stid > 1)
+		    call ap_rparam (out, KY_ZMAG, rval, UN_PZMAG,
+			"zero point of magnitude scale")
+		newmag = YES
+	    }
+
+	case QCMD_EPADU:
+	    call gargr (rval)
+	    if (nscan() == 1) {
+		call printf ("%s = %g\n")
+		    call pargstr (KY_EPADU)
+		    call pargr (apstatr (ap, EPADU))
+	    } else {
+		call apsetr (ap, EPADU, rval)
+		if (stid > 1)
+		    call ap_rparam (out, KY_EPADU, rval, UN_NEPADU, "gain")
+		newmag = YES
+	    }
+
+	case QCMD_EXPOSURE:
+	    call gargstr (Memc[cmd], SZ_LINE)
+	    if (Memc[cmd] == EOS) {
+		call apstats (ap, EXPOSURE, Memc[str], SZ_FNAME)
+		call printf ("%s = %s\n")
+		    call pargstr (KY_EXPOSURE)
+		    call pargstr (Memc[str])
+	    } else {
+		ip = 1
+		if (ctowrd (Memc[cmd], ip, Memc[str], SZ_FNAME) <= 0)
+		    Memc[str] = EOS
+		call apsets (ap, EXPOSURE, Memc[str])
+		if (im != NULL)
+		    call ap_itime (im, ap)
+		if (stid > 1)
+		    call ap_sparam (out, KY_EXPOSURE, Memc[str],
+		        UN_AKEYWORD, "exposure time keyword")
+	    }
+
+	case QCMD_AIRMASS:
+	    call gargstr (Memc[cmd], SZ_LINE)
+	    if (Memc[cmd] == EOS) {
+		call apstats (ap, AIRMASS, Memc[str], SZ_FNAME)
+		call printf ("%s = %s\n")
+		    call pargstr (KY_AIRMASS)
+		    call pargstr (Memc[str])
+	    } else {
+		ip = 1
+		if (ctowrd (Memc[cmd], ip, Memc[str], SZ_FNAME) <= 0)
+		    Memc[str] = EOS
+		call apsets (ap, AIRMASS, Memc[str])
+		if (im != NULL)
+		    call ap_airmass (im, ap)
+		if (stid > 1)
+		    call ap_sparam (out, KY_AIRMASS, Memc[str],
+		        UN_AKEYWORD, "airmass keyword")
+	    }
+
+	case QCMD_FILTER:
+	    call gargstr (Memc[cmd], SZ_LINE)
+	    if (Memc[cmd] == EOS) {
+		call apstats (ap, FILTER, Memc[str], SZ_FNAME)
+		call printf ("%s = %s\n")
+		    call pargstr (KY_FILTER)
+		    call pargstr (Memc[str])
+	    } else {
+		ip = 1
+		if (ctowrd (Memc[cmd], ip, Memc[str], SZ_FNAME) <= 0)
+		    Memc[str] = EOS
+		call apsets (ap, FILTER, Memc[str])
+		if (im != NULL)
+		    call ap_filter (im, ap)
+		if (stid > 1)
+		    call ap_sparam (out, KY_FILTER, Memc[str],
+		        UN_AKEYWORD, "filter keyword")
+	    }
+
+	case QCMD_OBSTIME:
+	    call gargstr (Memc[cmd], SZ_LINE)
+	    if (Memc[cmd] == EOS) {
+		call apstats (ap, OBSTIME, Memc[str], SZ_FNAME)
+		call printf ("%s = %s\n")
+		    call pargstr (KY_OBSTIME)
+		    call pargstr (Memc[str])
+	    } else {
+		ip = 1
+		if (ctowrd (Memc[cmd], ip, Memc[str], SZ_FNAME) <= 0)
+		    Memc[str] = EOS
+		call apsets (ap, OBSTIME, Memc[str])
+		if (im != NULL)
+		    call ap_otime (im, ap)
+		if (stid > 1)
+		    call ap_sparam (out, KY_OBSTIME, Memc[str],
+		        UN_AKEYWORD, "filter keyword")
+	    }
+
+	case QCMD_RADPLOTS:
+	    call gargb (bval)
+	    if (nscan () == 1) {
+		call printf ("%s = %b\n")
+		    call pargstr (KY_RADPLOTS)
+		    call pargb (itob (apstati (ap, RADPLOTS)))
+	    } else {
+		call apseti (ap, RADPLOTS, btoi (bval))
+	    }
+
+	case QCMD_IMAGE:
+	    call gargwrd (Memc[cmd], SZ_LINE)
+	    call apstats (ap, IMNAME, Memc[str], SZ_FNAME)
+	    if (Memc[cmd] == EOS || streq (Memc[cmd], Memc[str])) {
+		call printf ("%s = %s\n")
+		    call pargstr (KY_IMNAME)
+		    call pargstr (Memc[str])
+	    } else {
+		if (im != NULL) {
+		    call imunmap (im)
+		    im = NULL
+		}
+		iferr {
+		    im = immap (Memc[cmd], READ_ONLY, 0)
+		} then {
+		    call erract (EA_WARN)
+		    call printf ("Reopening image %s.\n")
+			call pargstr (Memc[str])
+		    im = immap (Memc[str], READ_ONLY, 0)
+		} else {
+		    call apimkeys (ap, im, Memc[cmd])
+		    newimage = YES
+		    newcbuf = YES; newcenter = YES
+		    newsbuf = YES; newsky = YES
+		    newmagbuf = YES; newmag = YES
+		}
+	    }
+
+	case QCMD_COORDS:
+	    call gargwrd (Memc[cmd], SZ_LINE)
+	    call apstats (ap, CLNAME, Memc[str], SZ_FNAME)
+	    if (Memc[cmd] == EOS || streq (Memc[cmd], Memc[str])) {
+		call printf ("%s:  %s\n")
+		    call pargstr (KY_CLNAME)
+		    call pargstr (Memc[str])
+	    } else {
+		if (cl != NULL) {
+		    call close( cl)
+		    cl = NULL
+		}
+		iferr {
+		    cl = open (Memc[cmd], READ_ONLY, TEXT_FILE)
+		} then {
+		    cl = NULL
+		    call erract (EA_WARN)
+		    call apsets (ap, CLNAME, "")
+		    call apsets (ap, CLROOT, "")
+		    call printf ("Coordinate file is undefined.\n")
+		} else {
+		    call apsets (ap, CLNAME, Memc[cmd])
+		    call apfroot (Memc[cmd], Memc[str], SZ_FNAME)
+		    call apsets (ap, CLROOT, Memc[str])
+		    ltid = 0
+		}
+	    }
+
+	case QCMD_OUTPUT:
+	    call gargwrd (Memc[cmd], SZ_LINE)
+	    call apstats (ap, OUTNAME, Memc[str], SZ_FNAME)
+	    if (Memc[cmd] == EOS || streq (Memc[cmd], Memc[str])) {
+		call printf ("%s = %s\n")
+		    call pargstr (KY_OUTNAME)
+		    call pargstr (Memc[str])
+	    } else {
+		if (out != NULL) {
+		    call close (out)
+		    out = NULL
+		    if (stid <= 1)
+			call delete (Memc[str])
+		}
+		iferr {
+		    out = open (Memc[cmd], READ_ONLY, TEXT_FILE)
+		} then {
+		    call erract (EA_WARN)
+		    call printf ("Reopening output file: %s\n")
+			call pargstr (Memc[str])
+		    if (Memc[str] != EOS)
+			out = open (Memc[str], APPEND, TEXT_FILE) 
+		    else
+		        out = NULL
+		} else {
+		    call apsets (ap, OUTNAME, Memc[cmd])
+		    stid = 1
+		}
+	    }
+
+	default:
+	    call printf ("Unknown or ambiguous colon command\7\n")
+	}
+
+	call sfree (sp)
+end
diff --git a/noao/digiphot/apphot/phot/apqphot.x b/noao/digiphot/apphot/phot/apqphot.x
new file mode 100644
index 00000000..b3c80b73
--- /dev/null
+++ b/noao/digiphot/apphot/phot/apqphot.x
@@ -0,0 +1,494 @@
+include <ctype.h>
+include <gset.h>
+include <imhdr.h>
+include "../lib/phot.h"
+include "../lib/apphot.h"
+include "../lib/display.h"
+include "../lib/center.h"
+include "../lib/fitsky.h"
+
+define	HELPFILE	"apphot$phot/qphot.key"
+
+# APQPHOT -- Procedure to compute quick magnitudes for a list of objects
+
+int procedure apqphot (ap, im, cl, gd, mgd, id, out, stid, interactive, cache)
+
+pointer ap			# pointer to apphot structure
+pointer	im			# pointer to IRAF image
+int	cl			# the coordinate list descriptor
+pointer	gd			# pointer to graphcis descriptor
+pointer	mgd			# pointer to the metacode file
+pointer	id			# pointer to image display stream
+int	out			# output file descriptor
+int	stid			# output file sequence number
+int	interactive		# interactive mode
+int	cache			# cache the input image pixels
+
+real	wx, wy, xlist, ylist
+pointer	sp, cmd
+int	newskybuf, newsky, newcenterbuf, newcenter, newmagbuf, newmag
+int	newimage, newlist, ip, wcs, key, colonkey, cier, sier, pier
+int	ltid, oid, prev_num, req_num, req_size, old_size, buf_size, memstat
+
+real	apstatr()
+int	clgcur(), apfitsky(), aprefitsky(), apfitcenter(), aprefitcenter()
+int	apmag(), apremag(), apstati(), apgqverify(), apnew(), ctoi()
+int	apgtverify(), apgscur(), ap_avsky(), ap_memstat(), sizeof()
+bool	fp_equalr()
+
+define  endswitch_ 99
+
+begin
+	# Initialize.
+	call smark (sp)
+	call salloc (cmd, SZ_LINE, TY_CHAR)
+
+	# Initialize cursor command.
+	key = ' '
+	Memc[cmd] = EOS
+
+	# Initialize the fitting parameters.
+	newimage = NO
+	newcenterbuf = YES; newcenter = YES
+	newskybuf = YES; newsky = YES
+	newmagbuf = YES; newmag = YES
+	cier = AP_OK; sier = AP_OK; pier = AP_OK
+
+	# Initialize the sequencing.
+	newlist = NO
+	ltid = 0
+
+	# Loop over the coordinate file.
+	while (clgcur ("icommands", wx, wy, wcs, key, Memc[cmd], SZ_LINE) !=
+	    EOF) {
+
+	    # Store the current cursor coordinates.
+            call ap_vtol (im, wx, wy, wx, wy, 1)
+	    call apsetr (ap, CWX, wx)
+	    call apsetr (ap, CWY, wy)
+
+	    if (apnew (ap, wx, wy, xlist, ylist, newlist) == YES) {
+		newcenterbuf = YES; newcenter = YES
+		newskybuf = YES; newsky = YES
+		newmagbuf = YES; newmag = YES
+	    }
+
+	    # Store previous cursor coordinates.
+	    call apsetr (ap, WX, apstatr (ap, CWX))
+	    call apsetr (ap, WY, apstatr (ap, CWY))
+
+	    # Loop over the colon keystroke commands.
+	    switch (key) {
+
+	    # Quit.
+	    case 'q':
+		if (interactive == YES) {
+		    if (apgqverify ("qphot", ap, key) == YES) {
+			call sfree (sp)
+			return (apgtverify (key))
+		    }
+		} else {
+		    call sfree (sp)
+		    return (NO)
+		}
+
+	    # Print out error messages.
+	    case 'e':
+		if (interactive == YES)
+		    call ap_perrors (ap, cier, sier, pier)
+
+	    # Print out the help page(s).
+	    case '?':
+		if ((id != NULL) && (id == gd))
+		    call gpagefile (id, HELPFILE, "")
+		else if (gd != NULL)
+		    call pagefile (HELPFILE, "[space=morehelp,q=quit,?=help]")
+
+	    # Process apphot colon commands.
+	    case ':':
+		for (ip = 1; IS_WHITE(Memc[cmd+ip-1]); ip = ip + 1)
+		    ;
+		colonkey = Memc[cmd+ip-1]
+		switch (colonkey) {
+		case 'm', 'n':
+
+		    # Show/set a qphot parameter.
+		    if (Memc[cmd+ip] != EOS && Memc[cmd+ip] != ' ') {
+			call apqcolon (ap, im, cl, out, stid, ltid, Memc[cmd], 
+		    	    newimage, newcenterbuf, newcenter, newskybuf,
+			    newsky, newmagbuf, newmag)
+			goto endswitch_
+		    }
+
+		    # No coordinate list.
+		    if (cl == NULL) {
+                        if (interactive == YES)
+                            call printf ("No coordinate list\n")
+                        goto endswitch_
+		    }
+
+		    # Get the next object.
+		    ip = ip + 1
+		    prev_num = ltid
+		    if (ctoi (Memc[cmd], ip, req_num) <= 0)
+		        req_num =  ltid + 1
+
+		    # Fetch the next object from the list.
+		    if (apgscur (cl, id, xlist, ylist, prev_num, req_num,
+			ltid) == EOF) {
+                        if (interactive == YES)
+                            call printf (
+                            "End of coordinate list, use r key to rewind\n")
+                        goto endswitch_
+		    }
+
+                    # Convert the coordinates.
+                    switch (apstati (ap, WCSIN)) {
+                    case WCS_PHYSICAL, WCS_WORLD:
+                        call ap_itol (ap,  xlist, ylist, xlist, ylist, 1)
+                    case WCS_TV:
+                        call ap_vtol (im, xlist, ylist, xlist, ylist, 1)
+                    default:
+                        ;
+                    }
+
+		    # Move to the next object.
+		    newlist = YES
+		    if (colonkey == 'm') {
+		        newcenterbuf = YES; newcenter = YES
+		        newskybuf = YES; newsky = YES
+		        newmagbuf = YES; newmag = YES
+                        goto endswitch_
+		    }
+
+		    # Measure object.
+		    cier = apfitcenter (ap, im, xlist, ylist)
+		    sier = apfitsky (ap, im, apstatr (ap, XCENTER),
+			apstatr (ap, YCENTER), NULL, gd)
+		    pier = apmag (ap, im, apstatr (ap, XCENTER), apstatr (ap,
+			YCENTER), apstati (ap, POSITIVE), apstatr (ap,
+			SKY_MODE), apstatr(ap, SKY_SIGMA), apstati (ap, NSKY))
+		    if (id != NULL) {
+		        call apmark (ap, id, apstati (ap, MKCENTER),
+			    apstati (ap, MKSKY), apstati (ap, MKAPERT))
+			if (id == gd)
+			    call gflush (id)
+			else
+			    call gframe (id)
+		     }
+		     call ap_pplot (ap, im, stid, gd, apstati (ap, RADPLOTS))
+		     if (interactive == YES)
+		         call ap_qpmag (ap, cier, sier, pier)
+		     if (stid == 1)
+		     call ap_param (ap, out, "qphot")
+		     call ap_pmag (ap, out, stid, ltid, cier, sier, pier)
+		     call ap_pplot (ap, im, stid, mgd, YES)
+		     stid = stid + 1
+		     newcenterbuf = NO; newcenter = NO
+		     newskybuf = NO; newsky = NO
+		     newmagbuf = NO; newmag = NO
+
+		default:
+		    call apqcolon (ap, im, cl, out, stid, ltid, Memc[cmd], 
+		        newimage, newcenterbuf, newcenter, newskybuf, newsky,
+			newmagbuf, newmag)
+		}
+
+		# Reestablish the correct viewport.
+		if (newimage == YES) {
+		    if ((id != NULL) && (id != gd))
+		        call ap_gswv (id, Memc[cmd], im, 4)
+                    req_size = MEMFUDGE * IM_LEN(im,1) * IM_LEN(im,2) *
+                        sizeof (IM_PIXTYPE(im))
+                    memstat = ap_memstat (cache, req_size, old_size)
+                    if (memstat == YES)
+                        call ap_pcache (im, INDEFI, buf_size)
+		}
+
+		newimage = NO
+
+	    # Save the current parameters in the pset files.
+	    case 'w':
+		call ap_qppars (ap)
+
+	    # Plot a centered stellar radial profile.
+	    case 'd':
+		if (interactive == YES) {
+		    call ap_qrad (ap, im, wx, wy, gd)
+		    newmagbuf = YES; newmag = YES
+		    newcenterbuf = YES; newcenter = YES
+		    newskybuf = YES; newsky = YES
+		}
+
+	    # Rewind the list.
+	    case 'r':
+		if (cl != NULL) {
+		    call seek (cl, BOF)
+		    ltid = 0
+		} else if (interactive == YES)
+		    call printf ("No coordinate list\n")
+
+	    # Process the remainder of the list.
+	    case 'l':
+		if (cl != NULL) {
+		    ltid = ltid + 1
+		    oid = stid
+		    call apbphot (ap, im, cl, NULL, out, stid, ltid, gd, mgd,
+			id, YES)
+		    ltid = ltid + stid - oid + 1
+		    if (id != NULL) {
+			if (id == gd)
+			    call gflush (id)
+			else
+			    call gframe (id)
+		    }
+		} else if (interactive == YES)
+		    call printf ("No coordinate list\n")
+
+	    # Get, measure next object in the list
+	    case 'm', 'n':
+
+                # No coordinate file.
+                if (cl == NULL) {
+                    if (interactive == YES)
+                        call printf ("No coordinate list\n")
+                    goto endswitch_
+
+                }
+
+		# Need to rewind the coordinate file.
+		prev_num = ltid
+		req_num =  ltid + 1
+		if (apgscur (cl, id, xlist, ylist, prev_num, req_num,
+		    ltid) == EOF) {
+                    if (interactive == YES)
+                        call printf (
+                            "End of coordinate list, use r key to rewind\n")
+                    goto endswitch_
+		}
+
+                # Convert coordinates if necessary.
+                switch (apstati (ap, WCSIN)) {
+                case WCS_PHYSICAL, WCS_WORLD:
+                    call ap_itol (ap,  xlist, ylist, xlist, ylist, 1)
+                case WCS_TV:
+                    call ap_vtol (im, xlist, ylist, xlist, ylist, 1)
+                default:
+                    ;
+                }
+
+		# Move to next object.
+		newlist = YES
+		if (key == 'm') {
+		    newcenterbuf = YES; newcenter = YES
+		    newskybuf = YES; newsky = YES
+		    newmagbuf = YES; newmag = YES
+                    goto endswitch_
+		}
+
+		# Measure next object.
+		cier = apfitcenter (ap, im, xlist, ylist)
+		sier = apfitsky (ap, im, apstatr (ap, XCENTER), apstatr (ap,
+		    YCENTER), NULL, gd)
+		pier = apmag (ap, im, apstatr (ap, XCENTER), apstatr (ap,
+		    YCENTER), apstati (ap, POSITIVE), apstatr (ap, SKY_MODE),
+		    apstatr (ap, SKY_SIGMA), apstati (ap, NSKY))
+		if (id != NULL) {
+		    call apmark (ap, id, apstati (ap, MKCENTER), apstati (ap,
+			MKSKY), apstati (ap, MKAPERT))
+		    if (id == gd)
+		        call gflush (id)
+		    else
+		        call gframe (id)
+		}
+		call ap_pplot (ap, im, stid, gd, apstati (ap, RADPLOTS))
+		if (interactive == YES)
+		    call ap_qpmag (ap, cier, sier, pier)
+		if (stid == 1)
+		    call ap_param (ap, out, "qphot")
+		call ap_pmag (ap, out, stid, ltid, cier, sier, pier)
+		call ap_pplot (ap, im, stid, mgd, YES)
+		stid = stid + 1
+		newcenterbuf = NO; newcenter = NO
+		newskybuf = NO; newsky = NO
+		newmagbuf = NO; newmag = NO
+
+	    # Setup phot parameters interactively.
+	    case 'i':
+		if (interactive == YES) {
+		    call ap_qradsetup (ap, im, wx, wy, gd, out, stid)
+		    newmagbuf = YES; newmag = YES
+		    newcenterbuf = YES; newcenter = YES
+		    newskybuf = YES; newsky = YES
+		}
+
+	     # Fit the center around the cursor position.
+	     case 'c':
+		if (newcenterbuf == YES)
+		    cier = apfitcenter (ap, im, wx, wy)
+		else if (newcenter == YES)
+		    cier = aprefitcenter (ap, im, cier)
+		if (id != NULL) {
+		    call apmark (ap, id, apstati (ap, MKCENTER), NO, NO)
+		    if (id == gd)
+			call gflush (id)
+		    else
+			call gframe (id)
+		}
+		call ap_cplot (ap, stid, gd, apstati (ap, RADPLOTS))
+		if (interactive == YES)
+		    call ap_qcenter (ap, cier)
+		newcenterbuf = NO
+		newcenter = NO
+
+	    # Fit the sky around the cursor position.
+	    case 't':
+	        if (newskybuf == YES || ! fp_equalr (wx,
+		    apstatr (ap, SXCUR)) || ! fp_equalr (wy, apstatr (ap,
+		    SYCUR)))
+		    sier = apfitsky (ap, im, wx, wy, NULL, gd)
+	        else if (newsky == YES)
+		    sier = aprefitsky (ap, im, gd)
+		if (id != NULL) {
+		    call apmark (ap, id, NO, apstati (ap, MKSKY), NO)
+		    if (id == gd)
+			call gflush (id)
+		    else
+			call gframe (id)
+		}
+		call ap_splot (ap, stid, gd, apstati (ap, RADPLOTS))
+		if (interactive == YES)
+		    call ap_qspsky (ap, sier)
+		newskybuf = NO; newsky = NO
+
+ 	    # Compute the average of several sky measurements around
+            # different cursor postions.
+            case 'a':
+                sier = ap_avsky (ap, im, stid, NULL, id, gd, interactive)
+                if (interactive == YES)
+                    call ap_qaspsky (ap, sier)
+                newskybuf = NO; newsky = NO
+
+	     # Fit the sky around the current center position. 
+	     case 's':
+	        if (newskybuf == YES || ! fp_equalr (apstatr (ap, XCENTER),
+		    apstatr (ap, SXCUR)) || ! fp_equalr (apstatr (ap, SYCUR),
+		    apstatr (ap, YCENTER)))
+		    sier = apfitsky (ap, im, apstatr (ap, XCENTER),
+		        apstatr (ap, YCENTER), NULL, gd)
+		else if (newsky == YES)
+		    sier = aprefitsky (ap, im, gd)
+		if (id != NULL) {
+		    call apmark (ap, id, NO, apstati (ap, MKSKY), NO)
+		    if (id == gd)
+			call gflush (id)
+		    else
+			call gframe (id)
+		}
+		call ap_splot (ap, stid, gd, apstati (ap, RADPLOTS))
+		if (interactive == YES)
+		    call ap_qspsky (ap, sier)
+		newskybuf = NO
+		newsky = NO
+
+	    # Compute magnitudes around the cursor position using the current
+	    # sky.
+	    case 'p', 'o':
+		if (newcenterbuf == YES)
+		    cier = apfitcenter (ap, im, wx, wy)
+		else if (newcenter == YES)
+		    cier = aprefitcenter (ap, im, cier)
+	        if (newmagbuf == YES || ! fp_equalr (apstatr (ap, XCENTER),
+		    apstatr (ap, PXCUR)) || ! fp_equalr (apstatr (ap,
+		    PYCUR), apstatr (ap, YCENTER)))
+		    pier = apmag (ap, im, apstatr (ap, XCENTER), apstatr (ap,
+		        YCENTER), apstati (ap, POSITIVE), apstatr (ap,
+			SKY_MODE), apstatr (ap, SKY_SIGMA), apstati (ap, NSKY))
+		else
+		    pier = apremag (ap, im, apstati (ap, POSITIVE), apstatr (ap,
+		        SKY_MODE), apstatr (ap, SKY_SIGMA), apstati (ap, NSKY))
+		if (id != NULL) {
+		    call apmark (ap, id, NO, NO, apstati (ap, MKAPERT))
+		    if (id == gd)
+			call gflush (id)
+		    else
+			call gframe (id)
+		}
+		if (interactive == YES)
+		    call ap_qpmag (ap, cier, sier, pier)
+		newmagbuf = NO; newmag = NO
+
+		if (key == 'o') {
+		    if (stid == 1)
+		        call ap_param (ap, out, "qphot")
+		    if (newlist == YES)
+		        call ap_pmag (ap, out, stid, ltid, cier, sier, pier)
+		    else
+		        call ap_pmag (ap, out, stid, 0, cier, sier, pier)
+		    call ap_pplot (ap, im, stid, mgd, YES)
+		    stid = stid + 1
+		}
+
+	    # Compute the center, sky, and magnitudes and save the results.
+	    case 'f', ' ':
+		if (newcenterbuf == YES)
+		    cier = apfitcenter (ap, im, wx, wy)
+		else if (newcenter == YES)
+		    cier = aprefitcenter (ap, im, cier)
+		if (newskybuf == YES || ! fp_equalr (apstatr (ap, XCENTER),
+		    apstatr (ap, SXCUR)) || ! fp_equalr (apstatr (ap, YCENTER),
+		    apstatr (ap, SYCUR)))
+		    sier = apfitsky (ap, im, apstatr (ap, XCENTER), apstatr (ap,
+		        YCENTER), NULL, gd)
+		else if (newsky == YES)
+		    sier = aprefitsky (ap, im, gd)
+		if (newmagbuf == YES || ! fp_equalr (apstatr (ap, XCENTER),
+		    apstatr (ap, PXCUR)) || ! fp_equalr (apstatr (ap, YCENTER),
+		    apstatr (ap, PYCUR)))
+		    pier = apmag (ap, im, apstatr (ap, XCENTER),
+		        apstatr (ap, YCENTER), apstati (ap, POSITIVE),
+			apstatr (ap, SKY_MODE), apstatr (ap, SKY_SIGMA),
+			apstati (ap, NSKY))
+		else
+		    pier = apremag (ap, im, apstati (ap, POSITIVE), apstatr (ap,
+		        SKY_MODE), apstatr (ap, SKY_SIGMA), apstati (ap, NSKY))
+
+		if (id != NULL) {
+		    call apmark (ap, id, apstati (ap, MKCENTER), apstati (ap,
+		        MKSKY), apstati (ap, MKAPERT))
+		    if (id == gd)
+			call gflush (id)
+		    else
+			call gframe (id)
+		}
+		call ap_pplot (ap, im, stid, gd, apstati (ap, RADPLOTS))
+		if (interactive == YES)
+		    call ap_qpmag (ap, cier, sier, pier)
+		
+		newcenterbuf = NO; newcenter = NO
+		newskybuf = NO; newsky = NO
+		newmagbuf = NO; newmag = NO
+
+		if (key == ' ') {
+		    if (stid == 1)
+		        call ap_param (ap, out, "qphot")
+		    if (newlist == YES)
+		        call ap_pmag (ap, out, stid, ltid, cier, sier, pier)
+		    else
+		        call ap_pmag (ap, out, stid, 0, cier, sier, pier)
+		    call ap_pplot (ap, im, stid, mgd, YES)
+		    stid = stid + 1
+		}
+
+	    default:
+		call printf ("Unknown or ambiguous keystroke command\n")
+	    }
+
+endswitch_
+	    # Setup for the next object.
+	    key = ' '
+	    Memc[cmd] = EOS
+	}
+
+	call sfree (sp)
+end
diff --git a/noao/digiphot/apphot/phot/apqppars.x b/noao/digiphot/apphot/phot/apqppars.x
new file mode 100644
index 00000000..cb87383b
--- /dev/null
+++ b/noao/digiphot/apphot/phot/apqppars.x
@@ -0,0 +1,42 @@
+include "../lib/apphot.h"
+include "../lib/center.h"
+include "../lib/fitsky.h"
+include "../lib/phot.h"
+include "../lib/noise.h"
+include "../lib/display.h"
+
+# AP_QPPARS -- Procedure to write out qthe phot task parameters.
+
+procedure ap_qppars (ap)
+
+pointer	ap		# pointer to apphot structure
+
+pointer	mp, str
+bool	itob()
+int	apstati()
+real	apstatr()
+
+begin
+	call smark (mp)
+	call salloc (str, SZ_LINE, TY_CHAR)
+
+	call clputr ("cbox", 2.0 * apstatr (ap, CAPERT))
+	call clputr ("annulus", apstatr (ap, ANNULUS))
+	call clputr ("dannulus", apstatr (ap, DANNULUS))
+	call apstats (ap, APERTS, Memc[str], SZ_LINE)
+	call clpstr ("apertures", Memc[str])
+
+	call apstats (ap, EXPOSURE, Memc[str], SZ_LINE)
+	call clpstr ("exposure", Memc[str])
+	call apstats (ap, AIRMASS, Memc[str], SZ_LINE)
+	call clpstr ("airmass", Memc[str])
+	call apstats (ap, FILTER, Memc[str], SZ_LINE)
+	call clpstr ("filter", Memc[str])
+	call apstats (ap, OBSTIME, Memc[str], SZ_LINE)
+	call clpstr ("obstime", Memc[str])
+	call clputr ("epadu", apstatr (ap, EPADU))
+	call clputr ("zmag", apstatr (ap, ZMAG))
+	call clputb ("radplots", itob (apstati (ap, RADPLOTS)))
+
+	call sfree (mp)
+end
diff --git a/noao/digiphot/apphot/phot/apqradsetup.x b/noao/digiphot/apphot/phot/apqradsetup.x
new file mode 100644
index 00000000..233cd8a7
--- /dev/null
+++ b/noao/digiphot/apphot/phot/apqradsetup.x
@@ -0,0 +1,105 @@
+include "../lib/apphot.h"
+include "../lib/display.h"
+include "../lib/fitsky.h"
+include "../lib/center.h"
+
+define	HELPFILE	"apphot$phot/iqphot.key"
+
+# AP_QRADSETUP -- Procedure to set up phot interactively using a radial profile
+# plot of a bright star.
+
+procedure ap_qradsetup (ap, im, wx, wy, gd, out, stid)
+
+pointer	ap			# pointer to apphot structure
+pointer	im			# pointer to the IRAF image
+real	wx, wy			# cursor coordinates
+pointer	gd			# pointer to graphics stream
+int	out			# output file descriptor
+int	stid			# output file sequence number
+
+int	cier, sier, pier, wcs, key
+pointer	sp, str, cmd
+real	xcenter, ycenter, rmin, rmax, imin, imax, xc, yc, rval
+real	u1, u2, v1, v2, x1, x2, y1, y2
+
+int	apfitcenter(), apfitsky(), ap_wmag(), apstati(), clgcur(), ap_showplot()
+real	apstatr(), ap_ccapert(), ap_cannulus(), ap_cdannulus()
+
+begin
+	# Check for open graphics stream
+	if (gd == NULL)
+	    return
+	call greactivate (gd, 0)
+
+	# Store the viewport and window coordinates.
+	call ggview (gd, u1, u2, v1, v2)
+	call ggwind (gd, x1, x2, y1, y2)
+
+	# Plot the radial profile.
+	if (ap_showplot (ap, im, wx, wy, gd, xcenter, ycenter, rmin, rmax,
+	    imin, imax) == ERR) {
+	    call gdeactivate (gd, 0)
+	    return
+	}
+
+	call smark (sp)
+	call salloc (cmd, SZ_LINE, TY_CHAR)
+	call salloc (str, SZ_LINE, TY_CHAR)
+
+        call printf (
+	"Waiting for setup menu command (?=help, v=default setup, q=quit):\n")
+	while (clgcur ("gcommands", xc, yc, wcs, key, Memc[cmd],
+	    SZ_LINE) != EOF) {
+
+	switch (key) {
+
+	    case 'q':
+	        break
+	    case '?':
+		call gpagefile (gd, HELPFILE, "")
+	    case 'c':
+	        rval = ap_ccapert (ap, gd, out, stid, rmin, rmax, imin, imax)
+	    case 'a':
+	        rval = ap_cannulus (ap, gd, out, stid, rmin, rmax, imin, imax)
+	    case 'd':
+	        rval = ap_cdannulus (ap, gd, out, stid, apstatr (ap, ANNULUS),
+		    rmin, rmax, imin, imax)
+	    case 'r':
+		call ap_caper (ap, gd, out, stid, Memc[str], rmin, rmax,
+		    imin, imax)
+	    case 'v':
+	        rval = ap_ccapert (ap, gd, out, stid, rmin, rmax, imin, imax)
+	        rval = ap_cannulus (ap, gd, out, stid, rmin, rmax, imin, imax)
+	        rval = ap_cdannulus (ap, gd, out, stid, apstatr (ap, ANNULUS),
+		    rmin, rmax, imin, imax)
+		call ap_caper (ap, gd, out, stid, Memc[str], rmin, rmax,
+		    imin, imax)
+	    default:
+		call printf ("Unknown or ambiguous keystroke command\007\n")
+	    }
+            call printf (
+	"Waiting for setup menu command (?=help, v=default setup, q=quit):\n")
+	}
+	call printf (
+	    "Interactive setup is complete. Type w to save parameters.\n")
+
+	# Restore the viewport and window coordinates.
+	call gsview (gd, u1, u2, v1, v2)
+	call gswind (gd, x1, x2, y1, y2)
+
+	call gdeactivate (gd, 0)
+	call sfree (sp)
+
+	# Print the answer.
+	cier = apfitcenter (ap, im, xcenter, ycenter)
+	if (! IS_INDEFR (apstatr (ap, XCENTER)) &&
+	    ! IS_INDEFR (apstatr (ap, YCENTER)))
+	    sier = apfitsky (ap, im, apstatr (ap, XCENTER), apstatr (ap,
+	        YCENTER), NULL, gd)
+	if (! IS_INDEFR (apstatr (ap, SKY_MODE)))
+	    pier = ap_wmag (ap, im, apstatr (ap, XCENTER), apstatr (ap,
+		YCENTER), apstati (ap, POSITIVE), apstatr (ap, SKY_MODE),
+		apstatr (ap, SKY_SIGMA), apstati (ap, NSKY))
+	call ap_pplot (ap, im, 0, gd, apstati (ap, RADPLOTS))
+	call ap_qpmag (ap, cier, sier, pier)
+end
diff --git a/noao/digiphot/apphot/phot/apqshow.x b/noao/digiphot/apphot/phot/apqshow.x
new file mode 100644
index 00000000..d8a4b6db
--- /dev/null
+++ b/noao/digiphot/apphot/phot/apqshow.x
@@ -0,0 +1,86 @@
+include "../lib/apphot.h"
+include "../lib/noise.h"
+include "../lib/display.h"
+include "../lib/center.h"
+include "../lib/fitsky.h"
+include "../lib/phot.h"
+
+# AP_QSHOW -- Procedure to display the current data parameters.
+
+procedure ap_qshow (ap)
+
+pointer	ap	# pointer to the apphot strucuture
+
+pointer	sp, str
+bool	itob()
+int	apstati()
+real	apstatr()
+
+begin
+	call smark (sp)
+	call salloc (str, SZ_LINE, TY_CHAR)
+
+	# Set the object charactersitics.
+	call printf ("Quick Phot Parameters\n")
+	call printf ("    %s: %s (%.2f,%.2f)    %s:  %s\n")
+	call apstats (ap, IMNAME, Memc[str], SZ_FNAME)
+	    call pargstr (KY_IMNAME)
+	    call pargstr (Memc[str])
+	    call pargr (apstatr (ap, CWX))
+	    call pargr (apstatr (ap, CWY))
+	call apstats (ap, OUTNAME, Memc[str], SZ_FNAME)
+	    call pargstr (KY_OUTNAME)
+	    call pargstr (Memc[str])
+
+	call printf ("    %s: %s\n")
+	call apstats (ap, CLNAME, Memc[str], SZ_FNAME)
+	    call pargstr (KY_CLNAME)
+	    call pargstr (Memc[str])
+
+	call printf ("    %s = %g %s\n")
+	    call pargstr (KY_CAPERT)
+	    call pargr (2.0* apstatr (ap, CAPERT))
+	    call pargstr ("pixels")
+
+	call printf ("    %s = %g %s    %s = %g %s\n")
+	    call pargstr (KY_ANNULUS)
+	    call pargr (apstatr (ap, ANNULUS))
+	    call pargstr ("pixels")
+	    call pargstr (KY_DANNULUS)
+	    call pargr (apstatr (ap, DANNULUS))
+	    call pargstr ("pixels")
+
+	call apstats (ap, APERTS, Memc[str], SZ_FNAME)
+	call printf ("    %s = %s %s    %s = %g %s\n")
+	    call pargstr (KY_APERTS)
+	    call pargstr (Memc[str])
+	    call pargstr ("pixels")
+	    call pargstr (KY_ZMAG)
+	    call pargr (apstatr (ap, ZMAG))
+	    call pargstr (UN_PZMAG)
+		
+	call printf ("    %s = %g %s\n")
+	    call pargstr (KY_EPADU)
+	    call pargr (apstatr (ap, EPADU))
+	    call pargstr (UN_NEPADU)
+	call printf ("    %s = %s    %s = %s\n")
+	call apstats (ap, EXPOSURE, Memc[str], SZ_FNAME)
+	    call pargstr (KY_EXPOSURE)
+	    call pargstr (Memc[str])
+	call apstats (ap, AIRMASS, Memc[str], SZ_FNAME)
+	    call pargstr (KY_AIRMASS)
+	    call pargstr (Memc[str])
+	call printf ("    %s = %s    %s = %s\n")
+	call apstats (ap, FILTER, Memc[str], SZ_FNAME)
+	    call pargstr (KY_FILTER)
+	    call pargstr (Memc[str])
+	call apstats (ap, OBSTIME, Memc[str], SZ_FNAME)
+	    call pargstr (KY_OBSTIME)
+	    call pargstr (Memc[str])
+
+	call printf ("    %s = %b\n")
+	    call pargstr (KY_RADPLOTS)
+	    call pargb (itob (apstati (ap, RADPLOTS)))
+
+	call sfree (sp)
+end
diff --git a/noao/digiphot/apphot/phot/apradsetup.x b/noao/digiphot/apphot/phot/apradsetup.x
new file mode 100644
index 00000000..b7f47f41
--- /dev/null
+++ b/noao/digiphot/apphot/phot/apradsetup.x
@@ -0,0 +1,126 @@
+include "../lib/apphot.h"
+include "../lib/display.h"
+include "../lib/center.h"
+include "../lib/fitsky.h"
+
+define	HELPFILE	"apphot$phot/iphot.key"
+
+# AP_RADSETUP -- Procedure to set up phot interactively using a radial profile
+# plot of a bright star.
+
+procedure ap_radsetup (ap, im, wx, wy, gd, out, stid)
+
+pointer	ap			# pointer to apphot structure
+pointer	im			# pointer to the IRAF image
+real	wx, wy			# cursor coordinates
+pointer	gd			# pointer to graphics stream
+int	out			# output file descriptor
+int	stid			# output file sequence number
+
+int	cier, sier, pier, key, wcs
+pointer	sp, cmd, str
+real	xcenter, ycenter, xc, yc, rmin, rmax, imin, imax
+real	u1, u2, v1, v2, x1, x2, y1, y2, rval
+
+int	apfitcenter(), apfitsky(), ap_wmag(), apstati(), clgcur(), ap_showplot()
+real	apstatr(), ap_cfwhmpsf(), ap_ccapert(), ap_cannulus(), ap_cdannulus()
+real	ap_csigma(), ap_crgrow(), ap_crclean(), ap_crclip()
+real	ap_cdatamin(), ap_cdatamax()
+
+begin
+	# Check for open graphics stream
+	if (gd == NULL)
+	    return
+	call greactivate (gd, 0)
+	call gclear (gd)
+
+	# Store the viewport and window coordinates.
+	call ggview (gd, u1, u2, v1, v2)
+	call ggwind (gd, x1, x2, y1, y2)
+
+	# Make the plot.
+	if (ap_showplot (ap, im, wx, wy, gd, xcenter, ycenter, rmin, rmax,
+	    imin, imax) == ERR) {
+	    call gdeactivate (gd, 0)
+	    return
+	}
+
+	# Initialize.
+	call smark (sp)
+	call salloc (cmd, SZ_LINE, TY_CHAR)
+	call salloc (str, SZ_LINE, TY_CHAR)
+
+	call printf (
+	 "Waiting for setup menu command (?=help, v=default setup, q=quit):\n")
+	while (clgcur ("gcommands", xc, yc, wcs, key, Memc[cmd],
+	    SZ_LINE) != EOF) {
+
+	switch (key) {
+
+	    case 'q':
+	        break
+	    case '?':
+		call gpagefile (gd, HELPFILE, "")
+	    case 'f':
+	        rval = ap_cfwhmpsf (ap, gd, out, stid, rmin, rmax, imin, imax)
+	    case 's':
+	        rval = ap_csigma (ap, gd, out, stid, rmin, rmax, imin, imax)
+	    case 'l':
+	        rval = ap_cdatamin (ap, gd, out, stid, rmin, rmax, imin, imax)
+	    case 'u':
+	        rval = ap_cdatamax (ap, gd, out, stid, rmin, rmax, imin, imax)
+	    case 'c':
+	        rval = ap_ccapert (ap, gd, out, stid, rmin, rmax, imin, imax)
+	    case 'n':
+	        rval = ap_crclean (ap, gd, out, stid, rmin, rmax, imin, imax)
+	    case 'p':
+	        rval = ap_crclip (ap, gd, out, stid, rmin, rmax, imin, imax)
+	    case 'a':
+	        rval = ap_cannulus (ap, gd, out, stid, rmin, rmax, imin, imax)
+	    case 'd':
+	        rval = ap_cdannulus (ap, gd, out, stid, apstatr (ap, ANNULUS),
+		    rmin, rmax, imin, imax)
+	    case 'g':
+	        rval = ap_crgrow (ap, gd, out, stid, rmin, rmax, imin, imax)
+	    case 'r':
+		call ap_caper (ap, gd, out, stid, Memc[str], rmin, rmax,
+		    imin, imax)
+	    case 'v':
+	        rval = ap_cfwhmpsf (ap, gd, out, stid, rmin, rmax, imin, imax)
+	        rval = ap_ccapert (ap, gd, out, stid, rmin, rmax, imin, imax)
+	        rval = ap_csigma (ap, gd, out, stid, rmin, rmax, imin, imax)
+	        #rval = ap_ccthresh (ap, gd, out, stid, rmin, rmax, imin, imax)
+	        rval = ap_cannulus (ap, gd, out, stid, rmin, rmax, imin, imax)
+	        rval = ap_cdannulus (ap, gd, out, stid, apstatr (ap, ANNULUS),
+		    rmin, rmax, imin, imax)
+		call ap_caper (ap, gd, out, stid, Memc[str], rmin, rmax,
+		    imin, imax)
+	    default:
+		call printf ("Unknown or ambiguous keystroke command\007\n")
+	    }
+	    call printf (
+	  "Waiting for setup menu command (?=help, v=default setup, q=quit):\n")
+	}
+	call printf (
+	    "Interactive setup is complete. Type w to save parameters.\n")
+
+	# Restore the viewport and window coordinates.
+	call gsview (gd, u1, u2, v1, v2)
+	call gswind (gd, x1, x2, y1, y2)
+
+	call gdeactivate (gd, 0)
+	call sfree (sp)
+
+	# Compute and print the answer.
+	cier = apfitcenter (ap, im, xcenter, ycenter)
+	if (! IS_INDEFR (apstatr (ap, XCENTER)) &&
+	    ! IS_INDEFR (apstatr (ap, YCENTER)))
+	    sier = apfitsky (ap, im, apstatr (ap, XCENTER), apstatr (ap,
+	        YCENTER), NULL, gd)
+	if (! IS_INDEFR (apstatr (ap, SKY_MODE)))
+	    pier = ap_wmag (ap, im, apstatr (ap, XCENTER), apstatr (ap,
+		YCENTER), apstati (ap, POSITIVE), apstatr (ap, SKY_MODE),
+		apstatr (ap, SKY_SIGMA), apstati (ap, NSKY))
+	call ap_pplot (ap, im, 0, gd, apstati (ap, RADPLOTS))
+	call ap_qpmag (ap, cier, sier, pier)
+end
diff --git a/noao/digiphot/apphot/phot/apremag.x b/noao/digiphot/apphot/phot/apremag.x
new file mode 100644
index 00000000..9cf705d4
--- /dev/null
+++ b/noao/digiphot/apphot/phot/apremag.x
@@ -0,0 +1,77 @@
+include <mach.h>
+include "../lib/apphotdef.h"
+include "../lib/apphot.h"
+include "../lib/noisedef.h"
+include "../lib/photdef.h"
+include "../lib/phot.h"
+
+# APREMAG -- Procedure to recompute the magnitudes inside a set of apertures
+# given that the sums and effective areas have already been computed.
+
+int procedure apremag (ap, im, positive, skyval, skysig, nsky)
+
+pointer	ap		# pointer to the apphot structure
+pointer	im		# the input image descriptor
+int	positive	# emission and absorption features
+real	skyval		# sky value
+real	skysig		# sigma of sky
+int	nsky		# number of sky pixels
+
+int	nap
+pointer	nse, phot
+real	zmag
+
+begin
+	# Initalize.
+	phot = AP_PPHOT(ap)
+	nse = AP_NOISE(ap)
+	call amovkr (INDEFR, Memr[AP_MAGS(phot)], AP_NAPERTS(phot))
+	call amovkr (INDEFR, Memr[AP_MAGERRS(phot)], AP_NAPERTS(phot))
+        if (IS_INDEFR(AP_PXCUR(phot)) || IS_INDEFR(AP_PYCUR(phot))) {
+            AP_OPXCUR(phot) = AP_PXCUR(phot)
+            AP_OPYCUR(phot) = AP_PYCUR(phot)
+        } else {
+            switch (AP_WCSOUT(ap)) {
+            case WCS_WORLD, WCS_PHYSICAL:
+                call ap_ltoo (ap, AP_PXCUR(phot), AP_PYCUR(phot),
+		    AP_OPXCUR(phot), AP_OPYCUR(phot), 1)
+            case WCS_TV:
+                call ap_ltov (im, AP_PXCUR(phot), AP_PYCUR(phot),
+		    AP_OPXCUR(phot), AP_OPYCUR(phot), 1)
+            default:
+                AP_OPXCUR(phot) = AP_PXCUR(phot)
+                AP_OPYCUR(phot) = AP_PYCUR(phot)
+            }
+        }
+
+	# Check for errors.
+	if (IS_INDEFR(AP_PXCUR(phot)) || IS_INDEFR(AP_PYCUR(phot)))
+	    return (AP_APERT_NOAPERT)
+	if (IS_INDEFR(skyval))
+	    return (AP_APERT_NOSKYMODE)
+
+	nap = min (AP_NMINAP(phot) - 1, AP_NMAXAP(phot))
+
+	# Compute the magnitudes and errors.
+	if (positive == YES)
+	    call apcopmags (Memd[AP_SUMS(phot)], Memd[AP_AREA(phot)],
+	        Memr[AP_MAGS(phot)], Memr[AP_MAGERRS(phot)], nap,
+	        skyval, skysig, nsky, AP_ZMAG(phot), AP_NOISEFUNCTION(nse),
+		AP_EPADU(nse))
+	else
+	    call apconmags (Memd[AP_SUMS(phot)], Memd[AP_AREA(phot)],
+	        Memr[AP_MAGS(phot)], Memr[AP_MAGERRS(phot)], nap,
+	        skyval, skysig, nsky, AP_ZMAG(phot), AP_NOISEFUNCTION(nse),
+		AP_EPADU(nse), AP_READNOISE(nse))
+
+	# Correct for itime.
+	zmag = 2.5 * log10 (AP_ITIME(ap))
+	call aaddkr (Memr[AP_MAGS(phot)], zmag, Memr[AP_MAGS(phot)], nap)
+
+	if (AP_NMAXAP(phot) < AP_NAPERTS(phot))
+	    return (AP_APERT_OUTOFBOUNDS)
+	else if (AP_NMINAP(phot) <= AP_NMAXAP(phot))
+	    return (AP_APERT_BADDATA)
+	else
+	    return (AP_OK)
+end
diff --git a/noao/digiphot/apphot/phot/iphot.key b/noao/digiphot/apphot/phot/iphot.key
new file mode 100644
index 00000000..679f2d50
--- /dev/null
+++ b/noao/digiphot/apphot/phot/iphot.key
@@ -0,0 +1,18 @@
+                    Interactive Phot Setup Menu
+
+	v	Mark and verify the critical parameters (f,s,c,a,d,r)
+
+	f	Mark and verify the full-width half-maximum of psf
+	s	Mark and verify the standard deviation of the background
+	l	Mark and verify the minimum good data value
+	u	Mark and verify the maximum good data value
+
+	c	Mark and verify the centering box width
+	n	Mark and verify the cleaning radius
+	p	Mark and verify the clipping radius
+
+	a	Mark and verify the inner radius of the sky annulus
+	d	Mark and verify the width of the sky annulus
+	g	Mark and verify the region growing radius
+
+	r	Mark and verify the aperture radii
diff --git a/noao/digiphot/apphot/phot/iqphot.key b/noao/digiphot/apphot/phot/iqphot.key
new file mode 100644
index 00000000..426bd523
--- /dev/null
+++ b/noao/digiphot/apphot/phot/iqphot.key
@@ -0,0 +1,8 @@
+                    Interactive Qphot Setup Menu
+
+	v	Mark and verify the critical parameters (c,a,d,r)
+
+	c	Mark and verify the centering box width
+	a	Mark and verify the inner radius of the sky annulus
+	d	Mark and verify the width of the sky annulus
+	r	Mark and verify the aperture radii
diff --git a/noao/digiphot/apphot/phot/mkpkg b/noao/digiphot/apphot/phot/mkpkg
new file mode 100644
index 00000000..8ca684f8
--- /dev/null
+++ b/noao/digiphot/apphot/phot/mkpkg
@@ -0,0 +1,81 @@
+# PHOT,QPHOT tasks
+
+$checkout libpkg.a ".."
+$update libpkg.a
+$checkin libpkg.a ".."
+$exit
+
+libpkg.a:
+	# general photometry and  PHOT task routines
+
+	apbphot.x	<fset.h>		../lib/apphot.h        \
+			../lib/center.h		../lib/display.h       \
+			../lib/fitsky.h
+	apcomags.x	<mach.h>		../lib/noise.h
+	apgppars.x	../lib/center.h		../lib/fitsky.h        \
+			../lib/phot.h		../lib/display.h       \
+			../lib/noise.h
+	apmag.x		<mach.h>		../lib/apphotdef.h     \
+			../lib/noisedef.h	../lib/photdef.h       \
+			../lib/apphot.h         ../lib/phot.h
+	apmagbuf.x	<imhdr.h>		../lib/apphotdef.h     \
+			../lib/photdef.h	../lib/phot.h
+	apmeasure.x
+	apppars.x	../lib/display.h
+	appconfirm.x	../lib/apphot.h		../lib/noise.h         \
+			../lib/center.h         ../lib/fitsky.h        \
+			../lib/phot.h
+	apperrors.x	../lib/phot.h
+	appfree.x	../lib/apphotdef.h	../lib/photdef.h
+	apphot.x	<ctype.h>		<gset.h>               \
+			../lib/apphot.h		../lib/display.h       \
+			../lib/center.h		../lib/fitsky.h        \
+			../lib/phot.h		<imhdr.h>
+	apphotcolon.x	../lib/noise.h		../lib/apphot.h        \
+			../lib/display.h	../lib/fitsky.h        \
+			../lib/center.h		../lib/phot.h          \
+			<gset.h>
+	appinit.x	../lib/apphotdef.h	../lib/photdef.h       \
+			../lib/phot.h
+	appplot.x	<gset.h>		<pkg/gtools.h>         \
+			../lib/apphot.h		../lib/noise.h         \
+			../lib/center.h		../lib/fitsky.h        \
+			../lib/phot.h
+	appmag.x	../lib/apphot.h		../lib/apphotdef.h     \
+			../lib/fitsky.h		../lib/center.h        \
+			../lib/photdef.h	../lib/phot.h
+	appshow.x	../lib/display.h	../lib/phot.h
+	apradsetup.x	../lib/fitsky.h		../lib/center.h        \
+			../lib/display.h	../lib/apphot.h
+	apremag.x	<mach.h>		../lib/apphotdef.h     \
+			../lib/noisedef.h       ../lib/photdef.h       \
+			../lib/apphot.h         ../lib/phot.h
+	t_phot.x	<fset.h>		<gset.h>	       \
+			<lexnum.h>		../lib/apphot.h        \
+			../lib/fitsky.h         <imhdr.h>
+
+	# QPHOT TASK SPECIFIC ROUTINES
+
+	apgqppars.x	"../lib/apphot.h"	"../lib/display.h"	\
+			"../lib/noise.h"	"../lib/center.h"	\
+			"../lib/fitsky.h"	"../lib/phot.h"
+	apqppars.x	"../lib/apphot.h"	"../lib/display.h"	\
+			"../lib/noise.h"	"../lib/center.h"	\
+			"../lib/fitsky.h"	"../lib/phot.h"
+	apqphot.x	<ctype.h>		<gset.h>		\
+			"../lib/apphot.h"	"../lib/display.h"	\
+			"../lib/center.h"	"../lib/fitsky.h"	\
+			"../lib/phot.h"         <imhdr.h>
+	apqradsetup.x "../lib/apphot.h"		"../lib/display.h"	\
+			"../lib/center.h"	"../lib/fitsky.h"
+	apqcolon.x	"../lib/apphot.h"	"../lib/display.h"	\
+			"../lib/noise.h"	"../lib/center.h"	\
+			"../lib/fitsky.h"	"../lib/phot.h"         \
+			<error.h>
+	apqshow.x	"../lib/apphot.h"	"../lib/display.h"	\
+			"../lib/noise.h"	"../lib/center.h"	\
+			"../lib/fitsky.h"	"../lib/phot.h"
+	t_qphot.x	<fset.h>		<gset.h>		\
+			<lexnum.h>		../lib/apphot.h   	\
+			../lib/fitsky.h         <imhdr.h>
+	;
diff --git a/noao/digiphot/apphot/phot/phot.key b/noao/digiphot/apphot/phot/phot.key
new file mode 100644
index 00000000..83e577fd
--- /dev/null
+++ b/noao/digiphot/apphot/phot/phot.key
@@ -0,0 +1,109 @@
+	Interactive Keystroke Commands
+
+?	Print help
+:	Colon commands
+v	Verify the critical parameters
+w	Save the current parameters
+d	Plot radial profile of current star
+i	Interactively set parameters using current star
+c	Fit center for current star
+t	Fit sky around cursor
+a	Average sky values fit around several cursor positions
+s	Fit sky around current centered star
+p	Do photometry for current star, using current sky
+o	Do photometry for current star, using current sky, output results
+f	Do photometry for current star
+spbar	Do photometry for current star, output results
+m	Move to next star in coordinate list
+n	Do photometry for next star in coordinate list, output results
+l	Do photometry for remaining stars in coordinate list, output results
+e	Print error messages
+r	Rewind coordinate list
+q	Exit task
+
+
+Photometry parameters are listed or set with the following commands.
+
+	Colon commands
+
+:show	[data/center/sky/phot]	List the parameters
+:m [n]	Move to next [nth] star in coordinate list
+:n [n]	Do photometry for next [nth] star in coordinate list, output results
+
+	Colon Parameter Editing Commands
+
+# Image and file name parameters
+
+:image		[string]	Image name
+:coords		[string]	Coordinate file name
+:output		[string]	Output file name
+
+# Data dependent parameters
+
+:scale		[value]		Image scale (units per pixel)
+:fwhmpsf	[value]		Full width half maximum of PSF (scale units)
+:emission	[y/n]		Emission feature (y), absorption (n)
+:sigma	        [value]		Standard deviation of sky (counts)
+:datamin	[value]		Minimum good data value (counts)
+:datamax	[value]		Maximum good data value (counts)
+
+# Noise parameters
+
+:noise		[string]	Noise model (constant|poisson)
+:gain		[string]	Gain image header keyword
+:ccdread	[string]	Readout noise image header keyword
+:epadu		[value]		Gain (electrons  per adu)
+:readnoise	[value]		Readout noise (electrons)
+
+# Observations parameters
+
+:exposure	[string]	Exposure time image header keyword
+:airmass	[string]	Airmass image header keyword
+:filter		[string]	Filter image header keyword
+:obstime	[string]	Time of observation image header keyword
+:itime 		[value]		Integration time (time units)
+:xairmass	[value]		Airmass value (number)
+:ifilter	[string]	Filter id string
+:otime		[string]	Time of observation (time units)
+
+# Centering algorithm parameters
+
+:calgorithm	[string]	Centering algorithm
+:cbox		[value]		Width of the centering box (scale units)
+:cthreshold	[value]		Centering intensity threshold (sigma)
+:cmaxiter	[value]		Maximum number of iterations
+:maxshift	[value]		Maximum center shift (scale units)
+:minsnratio	[value]		Minimum S/N ratio for centering
+:clean		[y/n]		Clean subraster before centering
+:rclean		[value]		Cleaning radius (scale units)
+:rclip		[value]		Clipping radius (scale units)
+:kclean		[value]		Clean K-sigma rejection limit (sigma)
+
+# Sky fitting algorithm parameters
+
+:salgorithm	[string]	Sky fitting algorithm
+:skyvalue	[value]		User supplied sky value (counts)
+:annulus	[value]		Inner radius of sky annulus (scale units)
+:dannulus	[value]		Width of sky annulus (scale units)
+:khist		[value]		Sky histogram extent (+/- sky sigma)
+:binsize	[value]		Resolution of sky histogram (sky sigma)
+:smooth		[y/n]		Lucy smooth the sky histogram
+:sloclip	[value]	        Low-side clipping factor in percent
+:shiclip	[value]	        High-side clipping factor in percent
+:smaxiter	[value]		Maximum number of iterations
+:snreject	[value]		Maximum number of rejection cycles
+:sloreject	[value]		Low-side pixel rejection limits (sky sigma)
+:shireject	[value]		High-side pixel rejection limits (sky sigma)
+:rgrow		[value]		Region growing radius (scale units)
+
+# Photometry parameters
+
+:apertures	[string]	List of aperture radii (scale units)
+:zmag		[value]		Zero point of magnitude scale
+
+# Plotting and marking parameters
+
+:mkcenter	[y/n]		Mark computed centers on display
+:mksky		[y/n]		Mark the sky annuli on the display
+:mkapert	[y/n]		Mark apertures on the display
+:radplot	[y/n]		Plot radial profile of object
diff --git a/noao/digiphot/apphot/phot/qphot.key b/noao/digiphot/apphot/phot/qphot.key
new file mode 100644
index 00000000..ff4dd5b7
--- /dev/null
+++ b/noao/digiphot/apphot/phot/qphot.key
@@ -0,0 +1,48 @@
+	Interactive Photometry Commands
+
+?	Print help
+:	Colon commands
+w	Save the current parameters
+d	Plot radial profile of current star
+i	Interactively set parameters using current star
+c	Fit center of current star
+t	Fit sky around cursor 
+a       Average sky values fit around several cursor positions
+s	Fit sky for current centered star
+p	Do photometry for current star, using current sky
+o	Do photometry for current star, using current sky, output results
+f	Do photometry for current star
+spbar	Do photometry for current star, output results
+e	Print error messages
+m	Move to next star in coordinate list
+n	Do photometry for next star in coordinate list, output results
+l	Do photometry for remaining stars in coordinate list, output results
+r	Rewind the coordinate list
+q	Exit task
+
+
+	Colon Commands
+
+:show				List the parameters
+:m [n]	Move to next [nth] star in coordinate list
+:n [n]	Do photometry for next [nth] star in coordinate list, output results
+
+	Colon Parameter Editing Commands
+
+:image		[string]	Image name
+:output		[string]	Output file name
+:coords		[string]	Coords file name
+
+:cbox		[value]		Width of the centering box (pixels)
+:annulus	[value]		Inner radius of sky annulus (pixels)
+:dannulus	[value]		Width of sky annulus (pixels)
+:apertures	[string]	List of aperture radii (pixels)
+:zmag		[value]		Zero point of magnitude scale (magnitudes)
+:epadu		[value]		Gain (electrons  per adu)
+
+:exposure	[string]	Exposure time image header keyword
+:airmass	[string]	Airmass image header keyword
+:filter		[string]	Filter image header keyword
+:obstime	[string]	Time of observation image header keyword
+
+:radplot	[y/n]		Plot radial profile of object
diff --git a/noao/digiphot/apphot/phot/t_phot.x b/noao/digiphot/apphot/phot/t_phot.x
new file mode 100644
index 00000000..9d35c994
--- /dev/null
+++ b/noao/digiphot/apphot/phot/t_phot.x
@@ -0,0 +1,341 @@
+include <fset.h>
+include <gset.h>
+include <lexnum.h>
+include <imhdr.h>
+include "../lib/apphot.h"
+include "../lib/fitsky.h"
+
+# T_PHOT -- Procedure to measure magnitudes inside a set of apertures for a list
+# of stars in a list of images.
+
+procedure t_phot ()
+
+pointer	image			# pointer name of the image
+pointer	output			# pointer output file name
+pointer	coords			# pointer to name of coords file
+pointer	skyfile			# pointer to name of file with sky values
+pointer	plotfile		# file of plot metacode
+pointer	graphics		# graphics display device
+pointer	display			# display device
+int	interactive		# mode of use
+int	cache			# cache the input image pixels in memory
+int	verify			# verify critical parameters in batch mode
+int	update			# update the critical parameters
+int	verbose			# type messages on the terminal
+
+pointer	sp, cname, outfname, str, ap, im, gd, mgd, id
+int	limlist, lclist, lolist, lslist, sid, lid, sd, out, cl, root, stat, pfd
+int	imlist, clist, olist, slist, memstat, old_size, wcs, req_size
+int	buf_size
+
+pointer	immap(), gopen()
+int	imtlen(), imtgetim(), clplen(), clgfil(), btoi(), apstati(), strncmp()
+int	fnldir(), strlen(), apphot(), imtopenp(), clpopnu(), open(), clgwrd()
+int	ap_memstat(), sizeof()
+bool	clgetb(), streq()
+errchk	gopen
+
+begin
+	# Allocate temporary space.
+	call smark (sp)
+	call salloc (image, SZ_FNAME, TY_CHAR)
+	call salloc (output, SZ_FNAME, TY_CHAR)
+	call salloc (coords, SZ_FNAME, TY_CHAR)
+	call salloc (skyfile, SZ_FNAME, TY_CHAR)
+	call salloc (plotfile, SZ_FNAME, TY_CHAR)
+	call salloc (graphics, SZ_FNAME, TY_CHAR)
+	call salloc (display, SZ_FNAME, TY_CHAR)
+	call salloc (outfname, SZ_FNAME, TY_CHAR)
+	call salloc (cname, SZ_FNAME, TY_CHAR)
+	call salloc (str, SZ_LINE, TY_CHAR)
+
+	# Set the standard output to flush on newline.
+	call fseti (STDOUT, F_FLUSHNL, YES)
+
+	# Get the task parameters.
+	imlist = imtopenp ("image")
+	limlist = imtlen (imlist)
+	clist = clpopnu ("coords")
+	lclist = clplen (clist)
+	olist = clpopnu ("output")
+	lolist = clplen (olist)
+
+	# Check that image and coordinate list lengths match.
+	if (limlist < 1 || (lclist > 1 && lclist != limlist)) {
+	    call imtclose (imlist)
+	    call clpcls (clist)
+	    call clpcls (olist)
+	    call error (0, "Imcompatible image and coordinate list lengths")
+	}
+
+	# Check that image and output list lengths match.
+	if (lolist > 1 && lolist != limlist) {
+	    call imtclose (imlist)
+	    call clpcls (clist)
+	    call clpcls (olist)
+	    call error (0, "Imcompatible image and output list lengths")
+	}
+
+	call clgstr ("icommands.p_filename", Memc[cname], SZ_FNAME)
+	if (Memc[cname] != EOS)
+	    interactive = NO
+	#else if (lclist == 0)
+	    #interactive = YES
+	else
+	    interactive = btoi (clgetb ("interactive"))
+	cache = btoi (clgetb ("cache"))
+	verbose = btoi (clgetb ("verbose"))
+	verify = btoi (clgetb ("verify"))
+	update = btoi (clgetb ("update"))
+
+	# Get the graphics and display devices.
+	call clgstr ("graphics", Memc[graphics], SZ_FNAME)
+	call clgstr ("display", Memc[display], SZ_FNAME)
+
+	# Open the graphics and display devices.
+	if (interactive == YES) {
+	    if (Memc[graphics] == EOS)
+		gd = NULL
+	    else {
+		iferr {
+		    gd = gopen (Memc[graphics], APPEND+AW_DEFER, STDGRAPH)
+		} then {
+		    call eprintf (
+		        "Warning: Error opening graphics device.\n")
+		    gd = NULL
+		}
+	    }
+	    if (Memc[display] == EOS)
+		id = NULL
+	    else if (streq (Memc[graphics], Memc[display]))
+		id = gd
+	    else {
+		iferr {
+		    id = gopen (Memc[display], APPEND, STDIMAGE)
+		} then {
+		    call eprintf (
+		"Warning: Graphics overlay not available for display device.\n")
+		    id = NULL
+		}
+	    }
+	} else {
+	    gd = NULL
+	    id = NULL
+	}
+
+	# Open the plot metacode file.
+	call clgstr ("plotfile", Memc[plotfile], SZ_FNAME)
+	if (Memc[plotfile] == EOS)
+	    pfd = NULL
+	else
+	    pfd = open (Memc[plotfile], APPEND, BINARY_FILE)
+	if (pfd != NULL)
+	    mgd = gopen (Memc[graphics], NEW_FILE, pfd)
+	else
+	    mgd = NULL
+
+	# Intialize the phot structure.
+	call ap_gppars (ap)
+
+	# Confirm the algorithm parameters.
+	if (verify == YES && interactive == NO) {
+	    call ap_pconfirm (ap, NULL, 1)
+	    if (update == YES)
+		call ap_ppars (ap)
+	}
+
+        # Get the wcs information.
+        wcs = clgwrd ("wcsin", Memc[str], SZ_LINE, WCSINSTR)
+        if (wcs <= 0) {
+            call eprintf (
+                "Warning: Setting the input coordinate system to logical\n")
+            wcs = WCS_LOGICAL
+        }
+        call apseti (ap, WCSIN, wcs)
+        wcs = clgwrd ("wcsout", Memc[str], SZ_LINE, WCSOUTSTR)
+        if (wcs <= 0) {
+            call eprintf (
+                "Warning: Setting the output coordinate system to logical\n")
+            wcs = WCS_LOGICAL
+        }
+        call apseti (ap, WCSOUT, wcs)
+
+	# Get the file name for the sky values.
+	if (apstati (ap, SKYFUNCTION) == AP_SKYFILE) {
+	    slist = clpopnu ("skyfile")
+	    lslist = clplen (slist)
+	    if (limlist < 1 || (lslist > 1 && lslist != limlist)) {
+	        call imtclose (imlist)
+	        call clpcls (clist)
+	        call clpcls (olist)
+		call clpcls (slist)
+	        call error (0, "Imcompatible image and sky file list lengths")
+	    }
+	} else
+	    sd = NULL
+
+	# Begin looping over the image list.
+	sid = 1
+	while (imtgetim (imlist, Memc[image], SZ_FNAME) != EOF) {
+
+	    # Open the image and store image parameters.
+	    im = immap (Memc[image], READ_ONLY, 0)
+	    call apimkeys (ap, im, Memc[image])
+
+	    # Set the image display viewport.
+	    if ((id != NULL) && (id != gd))
+		call ap_gswv (id, Memc[image], im, 4)
+
+	    # Cache the input image pixels.
+            req_size = MEMFUDGE * IM_LEN(im,1) * IM_LEN(im,2) *
+                sizeof (IM_PIXTYPE(im))
+            memstat = ap_memstat (cache, req_size, old_size)
+            if (memstat == YES)
+                call ap_pcache (im, INDEFI, buf_size)
+
+	    # Open the coordinate file, where coords is assumed to be a simple
+	    # text file in which the x and y positions are in columns 1 and 2
+	    # respectively and all remaining fields are ignored.
+
+	    if (lclist <= 0) {
+		cl = NULL
+		call strcpy ("", Memc[outfname], SZ_FNAME)
+	    } else {
+		stat = clgfil (clist, Memc[coords], SZ_FNAME)
+		root = fnldir (Memc[coords], Memc[outfname], SZ_FNAME)
+		if (strncmp ("default", Memc[coords+root], 7) == 0 || root ==
+		    strlen (Memc[coords])) {
+		    call ap_inname (Memc[image], Memc[outfname], "coo",
+		        Memc[outfname], SZ_FNAME)
+		    lclist = limlist
+	            cl = open (Memc[outfname], READ_ONLY, TEXT_FILE)
+		} else if (stat != EOF) {
+		    call strcpy (Memc[coords], Memc[outfname], SZ_FNAME)
+	            cl = open (Memc[outfname], READ_ONLY, TEXT_FILE)
+		} else {
+		    call apstats (ap, CLNAME, Memc[outfname], SZ_FNAME)
+		    call seek (cl, BOF)
+		}
+	    }
+	    call apsets (ap, CLNAME, Memc[outfname])
+	    call apfroot (Memc[outfname], Memc[str], SZ_LINE)
+	    call apsets (ap, CLROOT, Memc[str])
+
+	    # Open the skys file.
+	    if (lslist <= 0) {
+		sd = NULL
+		call strcpy ("", Memc[skyfile], SZ_FNAME)
+	    } else if (clgfil (slist, Memc[skyfile], SZ_FNAME) != EOF)
+		sd = open (Memc[skyfile], READ_ONLY, TEXT_FILE)
+	    else
+		call seek (sd, BOF)
+	    #call apsets (ap, SKYNAME, Memc[skyfile])
+
+	    # Open the output text file, if output is "default", dir$default or
+	    # a directory specification then the extension "mag" is added to the
+	    # image name and a suitable version number is appended to the output
+	    # name. If output is the null string then no output file is created.
+
+	    if (lolist == 0) {
+		out = NULL
+		call strcpy ("", Memc[outfname], SZ_FNAME)
+	    } else {
+	        stat = clgfil (olist, Memc[output], SZ_FNAME)
+		root = fnldir (Memc[output], Memc[outfname], SZ_FNAME)
+		if (strncmp ("default", Memc[output+root], 7) == 0 || root ==
+		    strlen (Memc[output])) {
+		    call apoutname (Memc[image], Memc[outfname], "mag",
+		        Memc[outfname], SZ_FNAME)
+		    out = open (Memc[outfname], NEW_FILE, TEXT_FILE)
+		    lolist = limlist
+		} else if (stat != EOF) {
+		    call strcpy (Memc[output], Memc[outfname], SZ_FNAME)
+		    out = open (Memc[outfname], NEW_FILE, TEXT_FILE)
+		} else
+		    call apstats (ap, OUTNAME, Memc[outfname], SZ_FNAME)
+	    }
+	    call apsets (ap, OUTNAME, Memc[outfname])
+
+	    # Do aperture photometry.
+	    if (interactive == NO) {
+	        if (Memc[cname] != EOS)
+		    stat = apphot (ap, im, cl, sd, NULL, mgd, NULL, out, sid,
+		        NO, cache)
+	        else if (cl != NULL) {
+		    lid = 1
+	            call apbphot (ap, im, cl, sd, out, sid, lid, gd, mgd, id,
+		        verbose)
+		    stat = NO
+		} else
+		    stat = NO
+	    } else
+		stat = apphot (ap, im, cl, sd, gd, mgd, id, out, sid, YES,
+		    cache)
+
+	    # Cleanup.
+	    call imunmap (im)
+	    if (cl != NULL) {
+		if (clplen(clist) > 1)
+		    call close (cl)
+	    }
+	    if (sd != NULL) {
+		if (lslist > 1)
+		    call close (sd)
+	    }
+	    if (out != NULL && lolist != 1) {
+		call close (out)
+		if (sid <= 1) {
+		    call apstats (ap, OUTNAME, Memc[outfname], SZ_FNAME)
+		    call delete (Memc[outfname])
+		}
+		sid = 1
+	    }
+
+	    # Uncache memory.
+	    call fixmem (old_size)
+
+	    if (stat == YES)
+		break
+	}
+
+
+	# Close the coordinate, sky and output files.
+	if (cl != NULL && lclist == 1)
+	    call close (cl)
+	if (sd != NULL && lslist == 1)
+	    call close (sd)
+	if (out != NULL && lolist == 1) {
+	    call close (out)
+	    if (sid <= 1) {
+		call apstats (ap, OUTNAME, Memc[outfname], SZ_FNAME)
+		call delete (Memc[outfname])
+	    }
+	}
+
+	# Close up the plot files.
+	if (id == gd && id != NULL)
+	    call gclose (id)
+	else {
+	    if (gd != NULL)
+	        call gclose (gd)
+	    if (id != NULL)
+	        call gclose (id)
+	}
+	if (mgd != NULL)
+	    call gclose (mgd)
+	if (pfd != NULL)
+	    call close (pfd)
+
+	# Free the apphot data structures.
+	call appfree (ap)
+
+	# Close the coord, sky and image lists.
+	call imtclose (imlist)
+	call clpcls (clist)
+	if (sd != NULL)
+	    call clpcls (slist)
+	call clpcls (olist)
+
+	# Free working space.
+	call sfree (sp)
+end
diff --git a/noao/digiphot/apphot/phot/t_qphot.x b/noao/digiphot/apphot/phot/t_qphot.x
new file mode 100644
index 00000000..91174e78
--- /dev/null
+++ b/noao/digiphot/apphot/phot/t_qphot.x
@@ -0,0 +1,293 @@
+include <fset.h>
+include <gset.h>
+include <lexnum.h>
+include <imhdr.h>
+include "../lib/apphot.h"
+include "../lib/fitsky.h"
+
+# T_QPHOT -- Procedure to measure magnitudes inside a set of apertures for a
+# list of stars in a list of images.
+
+procedure t_qphot ()
+
+pointer	image			# pointer name of the image
+pointer	output			# pointer output file name
+pointer	coords			# pointer to the coordinate file
+pointer	plotfile		# file of plot metacode
+pointer	graphics		# graphics display device
+pointer	display			# display device
+int	cache			# cache input image pixels in memory
+int	verbose			# verbose mode	
+
+pointer	sp, outfname, cname, ap, im, gd, mgd, id, str
+int	limlist, lclist, lolist, cl, sid, lid, out, root, stat, pfd, interactive
+int	imlist, olist, clist, memstat, wcs, req_size, old_size, buf_size
+
+pointer	immap(), gopen()
+int	imtlen(), imtgetim(), clplen(), clgfil(), btoi(), strncmp()
+int	fnldir(), strlen(), apqphot(), imtopenp(), clpopnu(), open()
+int	clgwrd(), ap_memstat(), sizeof()
+bool	clgetb(), streq()
+errchk	gopen
+
+begin
+	# Allocate temporary space.
+	call smark (sp)
+	call salloc (image, SZ_FNAME, TY_CHAR)
+	call salloc (coords, SZ_FNAME, TY_CHAR)
+	call salloc (output, SZ_FNAME, TY_CHAR)
+	call salloc (plotfile, SZ_FNAME, TY_CHAR)
+	call salloc (graphics, SZ_FNAME, TY_CHAR)
+	call salloc (display, SZ_FNAME, TY_CHAR)
+	call salloc (outfname, SZ_FNAME, TY_CHAR)
+	call salloc (cname, SZ_FNAME, TY_CHAR)
+	call salloc (str, SZ_FNAME, TY_CHAR)
+
+	# Set the standard output to flush on newline.
+	call fseti (STDOUT, F_FLUSHNL, YES)
+
+	# Get the task parameters.
+	imlist = imtopenp ("image")
+	limlist = imtlen (imlist)
+	clist = clpopnu ("coords")
+	lclist = clplen (clist)
+	olist = clpopnu ("output")
+	lolist = clplen (olist)
+
+	# Check that image and coordinate list lengths match.
+	if (limlist < 1 || (lclist > 1 && lclist != limlist)) {
+	    call imtclose (imlist)
+	    call clpcls (clist)
+	    call clpcls (olist)
+	    call error (0, "Imcompatible image and coordinate list lengths")
+	}
+
+	# Check that image and output list lengths match.
+	if (lolist > 1 && lolist != limlist) {
+	    call imtclose (imlist)
+	    call clpcls (olist)
+	    call error (0, "Imcompatible image and output list lengths")
+	}
+
+	# Intialize the phot structure.
+	call clgstr ("icommands.p_filename", Memc[cname], SZ_FNAME)
+	if (Memc[cname] != EOS)
+	    interactive = NO
+	#else if (lclist == 0)
+	    #interactive = YES
+	else
+	    interactive = btoi (clgetb ("interactive"))
+	cache = btoi (clgetb ("cache"))
+	verbose = btoi (clgetb ("verbose"))
+
+	# Get the parameters.
+	call ap_gqppars (ap)
+
+        # Get the wcs information.
+        wcs = clgwrd ("wcsin", Memc[str], SZ_LINE, WCSINSTR)
+        if (wcs <= 0) {
+            call eprintf (
+                "Warning: Setting the input coordinate system to logical\n")
+            wcs = WCS_LOGICAL
+        }
+        call apseti (ap, WCSIN, wcs)
+        wcs = clgwrd ("wcsout", Memc[str], SZ_LINE, WCSOUTSTR)
+        if (wcs <= 0) {
+            call eprintf (
+                "Warning: Setting the output coordinate system to logical\n")
+            wcs = WCS_LOGICAL
+        }
+        call apseti (ap, WCSOUT, wcs)
+
+	# Get the graphics and display devices.
+	call clgstr ("graphics", Memc[graphics], SZ_FNAME)
+	call clgstr ("display", Memc[display], SZ_FNAME)
+
+	# Open the plot files.
+	if (interactive == YES) {
+	    if (Memc[graphics] == EOS)
+		gd = NULL
+	    else {
+		iferr {
+		    gd = gopen (Memc[graphics], APPEND+AW_DEFER, STDGRAPH)
+		} then {
+		    call eprintf (
+		        "Warning: Error opening graphics device.\n")
+		    gd = NULL
+		}
+	    }
+	    if (Memc[display] == EOS)
+		id = NULL
+	    else if (streq (Memc[graphics], Memc[display]))
+		id = gd
+	    else {
+		iferr {
+		    id = gopen (Memc[display], APPEND, STDIMAGE)
+		} then {
+		    call eprintf (
+		"Warning: Graphics overlay not available for display device.\n")
+		    id = NULL
+		}
+	    }
+	} else {
+	    gd = NULL
+	    id = NULL
+	}
+
+	# Open the plot metacode file.
+	call clgstr ("plotfile", Memc[plotfile], SZ_FNAME)
+	if (Memc[plotfile] == EOS)
+	    pfd = NULL
+	else
+	    pfd = open (Memc[plotfile], APPEND, BINARY_FILE)
+	if (pfd != NULL)
+	    mgd = gopen (Memc[graphics], NEW_FILE, pfd)
+	else
+	    mgd = NULL
+
+	# Begin looping over the image list.
+	sid = 1
+	while (imtgetim (imlist, Memc[image], SZ_FNAME) != EOF) {
+
+	    # Open the image and store image parameters.
+	    im = immap (Memc[image], READ_ONLY, 0)
+	    call apimkeys (ap, im, Memc[image])
+
+	    # Set the image display viewport.
+	    if ((id != NULL) && (id != gd))
+		call ap_gswv (id, Memc[image], im, 4)
+
+	    # Cache the input image pixels.
+            req_size = MEMFUDGE * IM_LEN(im,1) * IM_LEN(im,2) *
+                sizeof (IM_PIXTYPE(im))
+            memstat = ap_memstat (cache, req_size, old_size)
+            if (memstat == YES)
+                call ap_pcache (im, INDEFI, buf_size)
+
+	    # Open the coordinate file, where coords is assumed to be a simple
+	    # text file in which the x and y positions are in columns 1 and 2
+	    # respectively and all remaining fields are ignored.
+
+	    if (lclist <= 0) {
+		cl = NULL
+		call strcpy ("", Memc[outfname], SZ_FNAME)
+	    } else {
+		stat = clgfil (clist, Memc[coords], SZ_FNAME)
+		root = fnldir (Memc[coords], Memc[outfname], SZ_FNAME)
+		if (strncmp ("default", Memc[coords+root], 7) == 0 || root ==
+		    strlen (Memc[coords])) {
+		    call ap_inname (Memc[image], Memc[outfname], "coo",
+		        Memc[outfname], SZ_FNAME)
+		    lclist = limlist
+	            cl = open (Memc[outfname], READ_ONLY, TEXT_FILE)
+		} else if (stat != EOF) {
+		    call strcpy (Memc[coords], Memc[outfname], SZ_FNAME)
+	            cl = open (Memc[outfname], READ_ONLY, TEXT_FILE)
+		} else {
+		    call apstats (ap, CLNAME, Memc[outfname], SZ_FNAME)
+		    call seek (cl, BOF)
+		}
+	    }
+	    call apsets (ap, CLNAME, Memc[outfname])
+	    call apfroot (Memc[outfname], Memc[str], SZ_FNAME)
+	    call apsets (ap, CLROOT, Memc[str])
+
+	    # Open the output text file, if output is "default", dir$default or
+	    # a directory specification then the extension "mag" is added to the
+	    # image name and a suitable version number is appended to the output
+	    # name. If output is the null string then no output file is created.
+
+	    if (lolist == 0) {
+		out = NULL
+		call strcpy ("", Memc[outfname], SZ_FNAME)
+	    } else {
+	        stat = clgfil (olist, Memc[output], SZ_FNAME)
+		root = fnldir (Memc[output], Memc[outfname], SZ_FNAME)
+		if (strncmp ("default", Memc[output+root], 7) == 0 || root ==
+		    strlen (Memc[output])) {
+		    call apoutname (Memc[image], Memc[outfname], "mag",
+		        Memc[outfname], SZ_FNAME)
+		    out = open (Memc[outfname], NEW_FILE, TEXT_FILE)
+		    lolist = limlist
+		} else if (stat != EOF) {
+		    call strcpy (Memc[output], Memc[outfname], SZ_FNAME)
+		    out = open (Memc[outfname], NEW_FILE, TEXT_FILE)
+		} else
+		    call apstats (ap, OUTNAME, Memc[outfname], SZ_FNAME)
+	    }
+	    call apsets (ap, OUTNAME, Memc[outfname])
+
+	    # Do aperture photometry.
+	    if (interactive == NO) {
+	        if (Memc[cname] != EOS)
+		    stat = apqphot (ap, im, cl, NULL, mgd, NULL, out, sid, NO,
+			cache)
+	        else if (cl != NULL) {
+		    lid = 1
+	            call apbphot (ap, im, cl, NULL, out, sid, lid, gd, mgd, id,
+		        verbose)
+		    stat = NO
+		} else
+		    stat = NO
+	    } else
+		stat = apqphot (ap, im, cl, gd, mgd, id, out, sid, YES, cache)
+
+	    # Cleanup.
+	    call imunmap (im)
+	    if (cl != NULL) {
+		if (lclist > 1)
+		    call close (cl)
+	    }
+	    if (out != NULL && lolist != 1) {
+		call close (out)
+		if (sid <= 1) {
+		    call apstats (ap, OUTNAME, Memc[outfname], SZ_FNAME)
+		    call delete (Memc[outfname])
+		}
+		sid = 1
+	    }
+
+	    # Uncache memory.
+	    call fixmem (old_size)
+
+	    if (stat == YES)
+		break
+	}
+
+
+	# Close the coordinate, sky and output files.
+	if (cl != NULL && lclist == 1)
+	    call close (cl)
+	if (out != NULL && lolist == 1) {
+	    call close (out)
+	    if (sid <= 1) {
+		call apstats (ap, OUTNAME, Memc[outfname], SZ_FNAME)
+		call delete (Memc[outfname])
+	    }
+	}
+
+	# Close up the plot files.
+	if (id == gd && id != NULL)
+	    call gclose (id)
+	else {
+	    if (gd != NULL)
+	        call gclose (gd)
+	    if (id != NULL)
+	        call gclose (id)
+	}
+	if (mgd != NULL)
+	    call gclose (mgd)
+	if (pfd != NULL)
+	    call close (pfd)
+
+	# Free the apphot data structure.
+	call appfree (ap)
+
+	# Close the coord, sky and image lists.
+	call imtclose (imlist)
+	call clpcls (clist)
+	call clpcls (olist)
+
+	# Free working space.
+	call sfree (sp)
+end
diff --git a/noao/digiphot/apphot/photpars.par b/noao/digiphot/apphot/photpars.par
new file mode 100644
index 00000000..87c7ac9e
--- /dev/null
+++ b/noao/digiphot/apphot/photpars.par
@@ -0,0 +1,7 @@
+# PHOTPARS Parameter File
+
+weighting,s,h,constant,"|constant|cone|gauss|",,Photometric weighting scheme for wphot
+apertures,s,h,"3.",,,List of aperture radii in scale units
+zmag,r,h,25.,,,Zero point of magnitude scale
+mkapert,b,h,no,,,Draw apertures on the display
+mode,s,h,'ql'
diff --git a/noao/digiphot/apphot/polymark.par b/noao/digiphot/apphot/polymark.par
new file mode 100644
index 00000000..6bf303e3
--- /dev/null
+++ b/noao/digiphot/apphot/polymark.par
@@ -0,0 +1,13 @@
+# POLYMARK
+
+image,f,a,,,,"The input image(s)"
+coords,f,h,"default",,,"The output coordinate file(s) (default: image.coo.?)"
+polygons,f,h,"default",,,"The output polygons file(s) (default: image.ver.?)"
+icommands,*imcur,h,"",,,"Image cursor: [x y wcs] key [cmd]"
+gcommands,*gcur,h,"",,,"Graphics cursor: [x y wcs] key [cmd]"
+wcsin,s,h,)_.wcsin,,,"The input coordinate system (logical,tv,physical,world)"
+wcsout,s,h,)_.wcsout,,,"The output coordinate system (logical,tv,physical)"
+cache,b,h,)_.cache,,,"Cache the input image pixels ?"
+graphics,s,h,)_.graphics,,,"Graphics device"
+display,s,h,)_.display,,,"Display device"
+mode,s,h,'ql'
diff --git a/noao/digiphot/apphot/polypars.par b/noao/digiphot/apphot/polypars.par
new file mode 100644
index 00000000..8b6aac6a
--- /dev/null
+++ b/noao/digiphot/apphot/polypars.par
@@ -0,0 +1,4 @@
+# Polyphot photometry parameters
+
+zmag,r,h,25.0,,,Zero point of magnitude scale
+mkpolygon,b,h,no,,,Draw polygon on the image display
diff --git a/noao/digiphot/apphot/polyphot.par b/noao/digiphot/apphot/polyphot.par
new file mode 100644
index 00000000..aefdf6b9
--- /dev/null
+++ b/noao/digiphot/apphot/polyphot.par
@@ -0,0 +1,22 @@
+# POLYPHOT
+
+image,f,a,,,,"The input image(s)"
+polygons,f,h,"",,,"The input polygons file(s) (default: image.ver.?)"
+coords,f,h,"",,,"The input coordinates file(s) (default: image.coo.?)"
+output,f,h,"default",,,"The output photometry file(s) (default: image.mag.?)"
+datapars,pset,h,"",,,"Data dependent parameters"
+centerpars,pset,h,"",,,"Centering parameters"
+fitskypars,pset,h,"",,,"Sky fitting parameters"
+polypars,pset,h,"",,,"Photometry parameters"
+interactive,b,h,yes,,,"Interactive mode ?"
+icommands,*imcur,h,"",,,"Image cursor: [x y wcs] key [cmd]"
+gcommands,*gcur,h,"",,,"Graphics cursor: [x y wcs] key [cmd]"
+wcsin,s,h,)_.wcsin,,,"The input coordinate system (logical,tv,physical,world)"
+wcsout,s,h,)_.wcsout,,,"The output coordinate system (logical,tv,physical)"
+cache,b,h,)_.cache,,,"Cache the input image pixels in memory ?"
+verify,b,h,)_.verify,,,"Verify critical parameters in non-interactive mode ?"
+update,b,h,)_.update,,,"Update critical parameters in non-interactive mode ?"
+verbose,b,h,)_.verbose,,,"Print messages in non-interactive mode ?"
+graphics,s,h,)_.graphics,,,"Graphics device"
+display,s,h,)_.display,,,"Display device"
+mode,s,h,'ql'
diff --git a/noao/digiphot/apphot/polyphot/apgypars.x b/noao/digiphot/apphot/polyphot/apgypars.x
new file mode 100644
index 00000000..960f9cbc
--- /dev/null
+++ b/noao/digiphot/apphot/polyphot/apgypars.x
@@ -0,0 +1,29 @@
+include "../lib/display.h"
+include "../lib/noise.h"
+include "../lib/center.h"
+include "../lib/fitsky.h"
+include "../lib/polyphot.h"
+
+# AP_GYPARS -- Procedure to fetch the polyphot task parameters.
+
+procedure ap_gypars (ap)
+
+pointer	ap		# pointer to apphot fitting structure
+
+begin
+	# Open the apphot strucuture.
+	call apyinit (ap, AP_CENTROID1D, 2.5, AP_MODE, 10.0, 10.0, 2.0,
+	    AP_NPOISSON)
+
+	# Get the data dependent parameters.
+	call ap_gdapars (ap)
+
+	# Get the centering algorithm parameters.
+	call ap_gcepars (ap)
+
+	# Get the sky fitting parameters.
+	call ap_gsapars (ap)
+
+	# Get the photometry parameters.
+	call ap_gpopars (ap)
+end
diff --git a/noao/digiphot/apphot/polyphot/apmkpylist.x b/noao/digiphot/apphot/polyphot/apmkpylist.x
new file mode 100644
index 00000000..6b9d1ea0
--- /dev/null
+++ b/noao/digiphot/apphot/polyphot/apmkpylist.x
@@ -0,0 +1,279 @@
+include <ctype.h>
+include <gset.h>
+include "../lib/apphot.h"
+include "../lib/polyphot.h"
+
+define	HELPFILE	"apphot$polyphot/polymark.key"
+
+# AP_MKPYLIST -- Procedure to make polygon and accompanying coordinate list.
+
+int procedure ap_mkpylist (im, py, pl, cl, id, gd, pid, cid)
+
+pointer	im		# pointer to IRAF image
+pointer	py		# pointer to the POLYPHOT structure
+int	pl		# starlist file descriptor
+int	cl		# coordinate file list
+pointer	id		# pointer to image display stream
+pointer	gd		# pointer to graphics display stream
+int	pid		# polygon id sequence number
+int	cid		# coordinate list sequence number
+
+int	key, nvertices, wcs, ptid, ltid, prev_num, req_num
+int	ip, colonkey, firstpoly, newpoly, delim
+pointer	sp, cmd, x, y, xshift, yshift
+real	wx, wy, xmean, ymean
+
+int	clgcur(), apgqverify(), apgtverify(), ap_ymkpoly(), ctoi()
+int	ap_ynextobj()
+real	apstatr()
+data	delim /';'/
+
+define	endswitch_  99
+
+begin
+	# Allocate temporary space.
+	call smark (sp)
+	call salloc (cmd, SZ_LINE, TY_CHAR)
+	call salloc (x, MAX_NVERTICES + 1, TY_REAL)
+	call salloc (y, MAX_NVERTICES + 1, TY_REAL)
+	call salloc (xshift, MAX_NVERTICES + 1, TY_REAL)
+	call salloc (yshift, MAX_NVERTICES + 1, TY_REAL)
+
+	# Initialize the cursor read.
+	key = ' '
+	Memc[cmd] = EOS
+
+	# Initialize the sequencing.
+	firstpoly = YES
+	newpoly = NO
+	ptid = 0
+	ltid = 0
+	xmean = INDEFR
+	ymean = INDEFR
+
+	# Loop over the polygon file.
+	nvertices = 0
+	while (clgcur ("icommands", wx, wy, wcs, key, Memc[cmd], SZ_LINE) !=
+	    EOF) {
+
+	    # Set the current cursor coordinates.
+	    call ap_vtol (im, wx, wy, wx, wy, 1)
+	    call apsetr (py, CWX, wx)
+	    call apsetr (py, CWY, wy)
+
+	    # Loop over the colon commands.
+	    switch (key) {
+
+	    # Quit.
+	    case 'q':
+		 if (apgqverify ("polymark", NULL, key) == YES) {
+		    call sfree (sp)
+		    return (apgtverify (key))
+		 }
+
+	    # Plot a centered stellar radial profile.
+	    case 'd':
+		call ap_qrad (py, im, wx, wy, gd)
+
+	    # Print the help page.
+	    case '?':
+		if ((id != NULL) && (id == gd))
+		    call gpagefile (id, HELPFILE, "")
+		else 
+		    call pagefile (HELPFILE, "[space=morehelp,q=quit,?=help]")
+
+	    # Colon escape commands.
+	    case ':':
+		for (ip = 1; IS_WHITE(Memc[cmd+ip-1]); ip = ip + 1)
+		    ;
+		colonkey = Memc[cmd+ip-1]
+
+		switch (colonkey) {
+		case 'm':
+
+		    # Decode a polymark colon command.
+		    if (Memc[cmd+ip] != EOS && Memc[cmd+ip] != ' ') {
+		        call printf (
+			    "Unknown or ambigous keystroke command\n")
+			goto endswitch_
+		    }
+
+		    # The polygon file is undefined.
+		    if (pl == NULL) {
+			call printf ("The polygon list is undefined\n")
+			goto endswitch_
+		    }
+
+		    # Read the next polygon.
+		    ip = ip + 1
+		    prev_num = ltid
+		    if (ctoi (Memc[cmd], ip, req_num) <= 0)
+			req_num = ltid + 1
+		    nvertices = ap_ynextobj (py, im, id, pl, cl, delim,
+			Memr[xshift], Memr[yshift], MAX_NVERTICES, prev_num,
+			req_num, ltid, ptid)
+		    if (nvertices == EOF) {
+			call printf (
+			    "End of polygon list, use r key to rewind\n")
+			goto endswitch_
+		    }
+
+		    # The polygon is undefined.
+		    if (nvertices < 3) {
+			call printf ("The polygon has fewer than 3 vertices\n")
+			goto endswitch_
+		    }
+
+		   # Mark the polygon.
+		   if (id != NULL) {
+		        call appymark (py, id, Memr[xshift], Memr[yshift],
+		           nvertices + 1, NO, NO, YES)
+			if (gd == id)
+			    call gflush (id)
+			else
+		    	    call gframe (id)
+		    }
+
+		default:
+		    call printf ("Unknown or ambigous keystroke command\n")
+		}
+
+	    # Draw the next polygon in the list.
+	    case 'm':
+
+		# No polygon file.
+		if (pl == NULL) {
+		    call printf ("The polygon list is undefined\n")
+		    goto endswitch_
+		}
+
+		# Read the next polygon.
+		prev_num = ltid
+		req_num = ltid + 1
+		nvertices = ap_ynextobj (py, im, id, pl, cl, delim,
+		    Memr[xshift], Memr[yshift], MAX_NVERTICES, prev_num,
+		    req_num, ltid, ptid)
+
+		# The polygon is undefined.
+		if (nvertices == EOF) {
+		    call printf ("End of polygon list, use r key to rewind\n")
+		    goto endswitch_
+	        }
+
+		# The polygon is ill-defined.
+		if (nvertices < 3) {
+		    call printf ("The polygon has fewer than 3 vertices\n")
+		    goto endswitch_
+		}
+
+		# Mark the polygon.
+		if (id != NULL) {
+		    call appymark (py, id, Memr[xshift], Memr[yshift],
+		        nvertices + 1, NO, NO, YES)
+		    if (gd == id)
+		    	call gflush (id)
+		    else
+		    	call gframe (id)
+		}
+
+	    # Rewind the polygon and coordinate lists.
+	    case 'r':
+		if (pl != NULL) {
+		    call seek (pl, BOF)
+		    if (cl != NULL)
+		        call seek (cl, BOF)
+		    ptid = 0
+		    ltid = 0
+		} else 
+		    call printf ("The polygon list is undefined\n")
+
+	    # Draw the remaining polygons on the display.
+	    case 'l':
+		if (pl == NULL) {
+		    call printf ("The polygon list is undefined\n")
+		} else if (id != NULL) {
+		    call ap_ydraw (py, im, cl, pl, ltid, ptid, id)
+		    if (gd == id)
+		        call gflush (id)
+		    else
+		        call gframe (id)
+		}
+
+	    # Define the polygon interactively.
+	    case 'g':
+		if (gd == id)
+		    nvertices = ap_ymkpoly (py, im, id, Memr[x], Memr[y],
+		        MAX_NVERTICES, NO)
+		else
+		    nvertices = ap_ymkpoly (py, im, id, Memr[x], Memr[y],
+		        MAX_NVERTICES, YES)
+		xmean = apstatr (py, PYXMEAN)
+		ymean = apstatr (py, PYYMEAN)
+		if (nvertices == EOF) {
+		    newpoly = NO
+		    call printf ("The polygon is undefined\n")
+		} else if (nvertices <= 2) {
+		    newpoly = NO
+		    call printf (
+		        "The polygon has fewer then 3 vertices\n")
+		} else { 
+		    newpoly = YES
+		    if (id != NULL) {
+			if (gd == id)
+			    call gflush (id)
+			else
+			    call gframe (id)
+		    }
+		}
+
+	    # Mark the current polygon on the display.
+	    case 'f':
+		if (id != NULL) {
+		    if (! IS_INDEFR(xmean) && ! IS_INDEFR(ymean)) {
+		        call aaddkr (Memr[x], wx - xmean, Memr[xshift],
+			    nvertices + 1)
+		        call aaddkr (Memr[y], wy - ymean, Memr[yshift],
+			    nvertices + 1)
+		        call appymark (py, id, Memr[xshift], Memr[yshift],
+		            nvertices + 1, NO, NO, YES)
+			if (gd == id)
+			    call gflush (id)
+			else
+			    call gframe (id)
+		    } else
+			call printf ("The polygon is undefined\n")
+		}
+
+
+	    # Mark the current polygon on the display and write to file.
+	    case ' ':
+		if (! IS_INDEFR(xmean) && ! IS_INDEFR(ymean)) {
+		    call ap_ywrite (py, im, cl, pl, Memr[x], Memr[y], nvertices,
+		        cid, pid, firstpoly, newpoly)
+		    if (id != NULL) {
+		        call aaddkr (Memr[x], wx - xmean, Memr[xshift],
+			    nvertices + 1)
+		        call aaddkr (Memr[y], wy - ymean, Memr[yshift],
+			    nvertices + 1)
+		        call appymark (py, id, Memr[xshift], Memr[yshift],
+		            nvertices + 1, NO, NO, YES)
+			if (gd == id)
+			    call gflush (id)
+			else
+			    call gframe (id)
+		    }
+		} else
+		    call printf ("The polygon is undefined\n")
+
+	    default:
+		call printf ("Unknown or ambigous keystroke command\n")
+	    }
+
+endswitch_
+	    # Reset the keystroke and command defaults.
+	    call apsetr (py, WX, apstatr (py, CWX))
+	    call apsetr (py, WY, apstatr (py, CWY))
+	    key = ' '
+	    Memc[cmd] = EOS
+	}
+end
diff --git a/noao/digiphot/apphot/polyphot/appyerrors.x b/noao/digiphot/apphot/polyphot/appyerrors.x
new file mode 100644
index 00000000..96a7bc93
--- /dev/null
+++ b/noao/digiphot/apphot/polyphot/appyerrors.x
@@ -0,0 +1,35 @@
+include "../lib/polyphot.h"
+
+# AP_PYERRORS -- Procedure to print out polyphot error messages when the
+# task is run in interactive mode.
+
+procedure ap_pyerrors (ap, cier, sier, pier)
+
+pointer	ap		# apphot structure
+int	cier		# centering error code
+int	sier		# sky fitting error code
+int	pier		# polyphot error code
+
+begin
+	# Print centering errors.
+	call ap_cerrors (ap, cier)
+
+	# Print sky fitting errors.
+	call ap_serrors (ap, sier)
+
+	# Print the polyphot errors.
+	switch (pier) {
+	case PY_NOPOLYGON:
+	    call printf ("The polygon is undefined or too few vertices.\n")
+	case PY_OUTOFBOUNDS:
+	    call printf ("The polygon is partially outside the image.\n")
+	case PY_NOPIX:
+	    call printf ("The effective polygon area is 0.0.\n")
+	case PY_NOSKYMODE:
+	    call printf ("The sky value is undefined.\n")
+	case PY_BADDATA:
+	    call printf ("Bad pixels inside the polygon.\n")
+	default:
+	    call printf ("")
+	}
+end
diff --git a/noao/digiphot/apphot/polyphot/apybphot.x b/noao/digiphot/apphot/polyphot/apybphot.x
new file mode 100644
index 00000000..8a4783e8
--- /dev/null
+++ b/noao/digiphot/apphot/polyphot/apybphot.x
@@ -0,0 +1,94 @@
+include <fset.h>
+include "../lib/apphot.h"
+include "../lib/display.h"
+include "../lib/fitsky.h"
+include "../lib/polyphot.h"
+
+# AP_YBPHOT -- Measure the flux inside a list of polygons.
+
+procedure ap_ybphot (py, im, cl, pl, out, id, ld, pd, gid, interactive)
+
+pointer py			# pointer to apphot structure
+pointer	im			# pointer to IRAF image
+int	cl			# coordinates file descriptor
+int	pl			# vertices list file descriptor
+int	out			# output file descriptor
+int	id			# output file sequence number
+int	ld			# coordinate list number
+int	pd			# polygon list number
+pointer	gid			# pointer to image display stream
+int	interactive		# interactive or batch mode
+
+real	apstatr()
+pointer	sp, x, y, xout, yout
+int	req_num, prev_num, cier, sier, pier, nvertices, delim
+int	ap_ynextobj(), ap_ycenter(), apfitsky(), ap_yfit(), apstati()
+data	delim /';'/
+
+begin
+	# Allocate temporary space for arrays.
+	call smark (sp)
+	call salloc (x, MAX_NVERTICES + 1, TY_REAL)
+	call salloc (y, MAX_NVERTICES + 1, TY_REAL)
+	call salloc (xout, MAX_NVERTICES + 1, TY_REAL)
+	call salloc (yout, MAX_NVERTICES + 1, TY_REAL)
+
+	# Initialize
+	if (pl != NULL)
+	    call seek (pl, BOF)
+	if (cl != NULL)
+	    call seek (cl, BOF)
+
+	# Get the first polygon.
+	pd = 0
+	prev_num = 0
+	req_num = ld + 1
+	nvertices = ap_ynextobj (py, im, gid, pl, cl, delim, Memr[x], Memr[y],
+	    MAX_NVERTICES, prev_num, req_num, ld, pd)
+
+	while (nvertices != EOF) {
+	    
+	    # Fit the center, sky and measure the polygon.
+	    cier = ap_ycenter (py, im, apstatr (py, PYCX), apstatr (py, PYCY),
+	        Memr[x], Memr[y], nvertices + 1)
+	    sier = apfitsky (py, im, apstatr (py, PYCX), apstatr (py,
+	        PYCY), NULL, NULL)
+	    pier = ap_yfit (py, im, Memr[x], Memr[y],
+		nvertices + 1, apstatr (py, SKY_MODE), apstatr (py,
+		SKY_SIGMA), apstati (py, NSKY))
+
+	    # Write the output to the standard output.
+	    if (interactive == YES) {
+	        call ap_qyprint (py, cier, sier, pier)
+		if (gid != NULL)
+		    call appymark (py, gid, Memr[x], Memr[y], nvertices + 1,
+		        YES, apstati (py, MKSKY), apstati (py, MKPOLYGON))
+	    }
+
+	    # Write the output to a file.
+	    if (id == 1)
+	        call ap_param (py, out, "polyphot")
+            switch (apstati(py,WCSOUT)) {
+            case WCS_WORLD, WCS_PHYSICAL:
+                call ap_ltoo (py, Memr[x], Memr[y], Memr[xout], Memr[yout],
+		    nvertices + 1)
+            case WCS_TV:
+                call ap_ltov (im, Memr[x], Memr[y], Memr[xout], Memr[yout],
+		    nvertices + 1)
+            default:
+		call amovr (Memr[x], Memr[xout], nvertices + 1)
+		call amovr (Memr[y], Memr[yout], nvertices + 1)
+            }
+	    call ap_yprint (py, out, Memr[xout], Memr[yout], nvertices, id, ld,
+	        pd, cier, sier, pier) 
+	    id = id + 1
+
+	    # Setup for next polygon.
+	    prev_num = ld
+	    req_num = ld + 1
+	    nvertices = ap_ynextobj (py, im, gid, pl, cl, delim, Memr[x],
+	        Memr[y], MAX_NVERTICES, prev_num, req_num, ld, pd)
+	}   
+
+	call sfree (sp)
+end
diff --git a/noao/digiphot/apphot/polyphot/apycenter.x b/noao/digiphot/apphot/polyphot/apycenter.x
new file mode 100644
index 00000000..faa2d884
--- /dev/null
+++ b/noao/digiphot/apphot/polyphot/apycenter.x
@@ -0,0 +1,59 @@
+include "../lib/center.h"
+include "../lib/polyphot.h"
+
+# AP_YCENTER -- Center the polygon using the centering package routines.
+
+int procedure ap_ycenter (py, im, wx, wy, x, y, nver)
+
+pointer	py		# pointer to polyphot structure
+pointer	im		# pointer to the IRAF image
+real	wx		# initial x center
+real	wy		# initial y center
+real	x[ARB]		# x coordinates of the polygon
+real	y[ARB]		# y coordinates of the polygon
+int	nver		# number of vertices
+
+int	cier
+int	apfitcenter()
+real	apstatr()
+
+begin
+	if (IS_INDEFR(apstatr (py, PYCX)) || IS_INDEFR(apstatr (py, PYCY)))
+	    cier = apfitcenter (py, im, INDEFR, INDEFR)
+	else
+	    cier = apfitcenter (py, im, wx, wy)
+
+	if (! IS_INDEFR (apstatr (py, XCENTER)) && ! IS_INDEFR (apstatr (py,
+	    YCENTER)) && ! IS_INDEFR (apstatr (py, PYCX)) &&
+	    ! IS_INDEFR (apstatr (py, PYCY)))
+	    call ap_yshift (py, im, x, y, nver, apstatr (py, XCENTER),
+	        apstatr (py, YCENTER))
+
+	return (cier)
+end
+
+
+# AP_YRECENTER -- Recenter the polygon using the existing buffer of pixels
+# and the centering package routines.
+
+int procedure ap_yrecenter (py, im, x, y, nver, cier)
+
+pointer	py		# pointer to polyphot structure
+pointer	im		# the input image descriptor
+real	x[ARB]		# x coordinates of the polygon
+real	y[ARB]		# y coordinates of the polygon
+int	nver		# number of vertices
+int	cier		# original centering error
+
+int	aprefitcenter()
+real	apstatr()
+
+begin
+	cier = aprefitcenter (py, im, cier)
+	if (! IS_INDEFR (apstatr (py, XCENTER)) && ! IS_INDEFR (apstatr (py,
+	    YCENTER)) && ! IS_INDEFR (apstatr (py, PYCX)) && !
+	    IS_INDEFR (apstatr (py, PYCY)))
+	    call ap_yshift (py, im, x, y, nver, apstatr (py, XCENTER),
+	        apstatr (py, YCENTER))
+	return (cier)
+end
diff --git a/noao/digiphot/apphot/polyphot/apycolon.x b/noao/digiphot/apphot/polyphot/apycolon.x
new file mode 100644
index 00000000..9b70199b
--- /dev/null
+++ b/noao/digiphot/apphot/polyphot/apycolon.x
@@ -0,0 +1,226 @@
+include <error.h>
+include <gset.h>
+include "../lib/apphot.h"
+include "../lib/noise.h"
+include "../lib/display.h"
+include "../lib/center.h"
+include "../lib/fitsky.h"
+include "../lib/polyphot.h"
+
+# AP_YCOLON -- Process polyphot task colon commands
+
+procedure ap_ycolon (ap, im, pl, cl, out, stid, ptid, ltid, cmdstr, newimage,
+        newcenterbuf, newcenter, newskybuf, newsky, newmagbuf, newmag)
+
+pointer	ap				# pointer to the apphot structure
+pointer	im				# pointer to the iraf image
+int	pl				# polygon file descriptor
+int     cl				# coord file descriptor
+int	out				# output file descriptor	
+int	stid				# output file number
+int	ptid				# polygon file sequence number
+int	ltid				# coord file sequence number
+char	cmdstr[ARB]			# command string
+int	newimage			# new image ?
+int	newcenterbuf, newcenter		# new center buffer ?, new center fit ?
+int	newskybuf, newsky		# new sky buffer ?, new sky fit ?
+int	newmagbuf, newmag		# new aperture buffer ?, new fit ?
+
+pointer	sp, incmd, outcmd
+int	strdic()
+
+begin
+	# Fetch the command.
+	call smark (sp)
+	call salloc (incmd, SZ_LINE, TY_CHAR)
+	call salloc (outcmd, SZ_LINE, TY_CHAR)
+
+	call sscan (cmdstr)
+	call gargwrd (Memc[incmd], SZ_LINE)
+	if (Memc[incmd] == EOS) {
+	    call sfree (sp)
+	    return
+	}
+
+	# Set the command to the appropriate routine.
+	if (strdic (Memc[incmd], Memc[outcmd], SZ_LINE, CCMDS) != 0)
+	    call apccolon (ap, out, stid, cmdstr, newcenterbuf, newcenter)
+	else if (strdic (Memc[incmd], Memc[outcmd], SZ_LINE, SCMDS) != 0)
+	    call apscolon (ap, out, stid, cmdstr, newskybuf, newsky)
+	else if (strdic (Memc[incmd], Memc[outcmd], SZ_LINE, APCMDS) != 0)
+	    call ap_apcolon (ap, im, cl, out, stid, ltid, cmdstr, newimage,
+	        newcenterbuf, newcenter, newskybuf, newsky, newmagbuf, newmag)
+	else if (strdic (Memc[incmd], Memc[outcmd], SZ_LINE, NCMDS) != 0)
+	    call ap_nscolon (ap, im, out, stid, cmdstr, newcenterbuf,
+	        newcenter, newskybuf, newsky, newmagbuf, newmag)
+	else if (strdic (Memc[incmd], Memc[outcmd], SZ_LINE, PYCMDS) != 0)
+	    call ap_yycolon (ap, pl, out, stid, ptid, ltid, cmdstr, newmagbuf,
+	        newmag)
+	else
+	    call ap_yimcolon (ap, cmdstr)
+
+	call sfree (sp)
+end
+
+
+# AP_YIMCOLON -- Procedure to process remaining polyphot commands which 
+
+procedure ap_yimcolon (ap, cmdstr)
+
+pointer	ap			# pointer to the apphot structure
+char	cmdstr[ARB]		# command string
+
+int	ncmd
+pointer	sp, cmd
+int	strdic()
+
+begin
+	# Fetch the command.
+	call smark (sp)
+	call salloc (cmd, SZ_LINE, TY_CHAR)
+
+	call sscan (cmdstr)
+	call gargwrd (Memc[cmd], SZ_LINE)
+	if (Memc[cmd] == EOS) {
+	    call sfree (sp)
+	    return
+	}
+
+	# Process the command.
+	ncmd = strdic (Memc[cmd], Memc[cmd], SZ_LINE, MISC1)
+	switch (ncmd) {
+	case 1:
+	    call gargwrd (Memc[cmd], SZ_LINE)
+	    ncmd = strdic (Memc[cmd], Memc[cmd], SZ_LINE, PYSHOWARGS)
+	    switch (ncmd) {
+	    case 1:
+		call printf ("\n")
+		call ap_cpshow (ap)
+		call printf ("\n")
+	    case 2:
+		call printf ("\n")
+		call ap_spshow (ap)
+		call printf ("\n")
+	    case 3:
+		call printf ("\n")
+		call ap_ypshow (ap)
+		call printf ("\n")
+	    case 4:
+		call printf ("\n")
+		call ap_nshow (ap)
+		call printf ("\n")
+	    default:
+		call printf ("\n")
+		call ap_yshow (ap)
+		call printf ("\n")
+	    }
+	default:
+	    call printf ("Unknown or ambiguous colon command\7\n")
+	}
+
+	call sfree (sp)
+end
+
+
+# AP_YYCOLON -- Procedure to process polyphot commands
+
+procedure ap_yycolon (ap, pl, out, stid, ptid, ltid, cmdstr, newmagbuf, newmag)
+
+pointer	ap		# pointer to apphot structure
+int	pl		# polygon file descriptor
+int	out		# output file descriptor
+int	stid		# output file sequence number
+int	ptid		# polygon file sequence number
+int	ltid		# coords file sequence number
+char	cmdstr[ARB]	# command string
+int	newmagbuf	# new aperture buffers ?
+int	newmag		# compute new magnitudes ?
+
+bool	bval
+int	ncmd
+pointer	sp, cmd, str
+real	rval
+string	cmds PYCMDS
+
+bool	itob(), streq()
+int	apstati(), btoi(), strdic(), nscan(), open()
+real	apstatr()
+errchk	open, close
+
+begin
+	# Allocate the space.
+	call smark (sp)
+	call salloc (cmd, SZ_LINE, TY_CHAR)
+	call salloc (str, SZ_FNAME, TY_CHAR)
+
+	call sscan (cmdstr)
+	call gargwrd (Memc[cmd], SZ_LINE)
+	if (Memc[cmd] == EOS) {
+	    call sfree (sp)
+	    return
+	}
+
+	# Process the colon command.
+	ncmd = strdic (Memc[cmd], Memc[cmd], SZ_LINE, cmds)
+	switch (ncmd) {
+
+	case PLCMD_ZMAG:
+	    call gargr (rval)
+	    if (nscan() == 1) {
+		call printf ("%s = %g\n")
+		    call pargstr (KY_PYZMAG)
+		    call pargr (apstatr (ap, PYZMAG))
+	    } else {
+		call apsetr (ap, PYZMAG, rval)
+		if (stid > 1)
+		    call ap_rparam (out, KY_PYZMAG, rval, UN_PYZMAG,
+			"zero point of magnitude scale")
+		newmag = YES
+	    }
+
+	case PLCMD_MKPOLYGON:
+	    call gargb (bval)
+	    if (nscan() == 1) {
+		call printf ("%s = %g\n")
+		    call pargstr (KY_MKPOLYGON)
+		    call pargb (itob (apstati (ap, MKPOLYGON)))
+	    } else {
+		call apseti (ap, MKPOLYGON, btoi (bval))
+	    }
+
+	case PLCMD_POLYGONS:
+	    call gargwrd (Memc[cmd], SZ_LINE)
+	    call apstats (ap, PYNAME, Memc[str], SZ_FNAME)
+	    if (Memc[cmd] == EOS || streq (Memc[cmd], Memc[str])) {
+		call printf ("%s = %s\n")
+		    call pargstr (KY_PYNAME)
+		    call pargstr (Memc[str])
+	    } else {
+		if (pl != NULL) {
+		    call close (pl)
+		    pl = NULL
+		}
+		iferr {
+		    pl = open (Memc[cmd], READ_ONLY, TEXT_FILE)
+		} then {
+		    pl = NULL
+		    call erract (EA_WARN)
+		    call apsets (ap, PYNAME, "")
+		    call apsets (ap, PYROOT, "")
+		    ptid = 0
+		    ltid = 0
+		} else {
+		    call apsets (ap, PYNAME, Memc[cmd])
+		    call apfroot (Memc[cmd], Memc[str], SZ_FNAME)
+		    call apsets (ap, PYROOT, Memc[str])
+		    ptid = 0
+		    ltid = 0
+		}
+	    }
+
+	default:
+	    call printf ("Unknown or ambiguous colon command\n")
+	}
+
+	call sfree (sp)
+end
diff --git a/noao/digiphot/apphot/polyphot/apyconfirm.x b/noao/digiphot/apphot/polyphot/apyconfirm.x
new file mode 100644
index 00000000..fb10ad32
--- /dev/null
+++ b/noao/digiphot/apphot/polyphot/apyconfirm.x
@@ -0,0 +1,99 @@
+include "../lib/apphot.h"
+include "../lib/noise.h"
+include "../lib/center.h"
+include "../lib/fitsky.h"
+
+# AP_YCONFIRM -- Procedure to confirm the critical polyphot parameters.
+
+procedure ap_yconfirm (ap, out, stid)
+
+pointer	ap		# pointer to the apphot structure
+int	out		# output file descriptor
+int	stid		# output file sequence number
+
+pointer	sp, cstr, sstr
+real	fwhmpsf, capert, annulus, dannulus, skysigma
+real	datamin, datamax
+int	apstati()
+real	apstatr(), ap_vfwhmpsf(), ap_vcapert(), ap_vsigma()
+real	ap_vannulus(), ap_vdannulus(), ap_vdatamin(), ap_vdatamax()
+
+begin
+	call smark (sp)
+	call salloc (cstr, SZ_FNAME, TY_CHAR)
+	call salloc (sstr, SZ_FNAME, TY_CHAR)
+
+	call printf ("\n")
+
+	# Confirm the centering algorithm.
+	call ap_vcstring (ap, Memc[cstr], SZ_FNAME)
+
+	if (apstati (ap, CENTERFUNCTION) != AP_NONE) {
+
+	    # Confirm the fwhmpsf.
+	    if (apstati (ap, CENTERFUNCTION) != AP_CENTROID1D)
+		fwhmpsf = ap_vfwhmpsf (ap)
+	    else
+	        fwhmpsf = apstatr (ap, FWHMPSF)
+
+	    # Confirm the centering box.
+	    capert = 2.0 * ap_vcapert (ap)
+
+	} else {
+	    fwhmpsf = apstatr (ap, FWHMPSF)
+	    capert = 2.0 * apstatr (ap, CAPERT)
+	}
+
+	# Confirm the sky fitting algorithm.
+	call ap_vsstring (ap, Memc[sstr], SZ_FNAME)
+
+	if (apstati (ap, SKYFUNCTION) != AP_CONSTANT &&
+	    apstati (ap, SKYFUNCTION) != AP_SKYFILE) {
+
+	    # Confirm the sky annulus parameter.
+	    annulus = ap_vannulus (ap)
+
+	    # Confirm the width of the sky annulus.
+	    dannulus = ap_vdannulus (ap)
+
+	} else {
+	    annulus = apstatr (ap, ANNULUS)
+	    dannulus = apstatr (ap, DANNULUS)
+	}
+
+	# Confirm the sky sigma parameter.
+	if (apstati (ap, SKYFUNCTION) != AP_SKYFILE)
+	    skysigma = ap_vsigma (ap)
+	else
+	    skysigma = apstatr (ap, SKYSIGMA)
+
+	# Confirm the datamin and datamax parameters.
+	datamin = ap_vdatamin (ap)
+	datamax = ap_vdatamax (ap)
+
+	call printf ("\n")
+
+	# Update the database file.
+	if (out != NULL && stid > 1) {
+	    call ap_sparam (out, KY_CSTRING, Memc[cstr], UN_CALGORITHM,
+		"centering algorithm")
+	    call ap_rparam (out, KY_FWHMPSF, fwhmpsf, UN_ASCALEUNIT,
+	        "full width half maximum of the psf")
+	    call ap_rparam (out, KY_CAPERT, capert, UN_CSCALEUNIT,
+	        "width of the centering box")
+	    call ap_sparam (out, KY_SSTRING, Memc[sstr], UN_SALGORITHM,
+		"sky fitting algorithm")
+	    call ap_rparam (out, KY_ANNULUS, annulus, UN_SSCALEUNIT,
+	        "inner radius of the sky annulus")
+	    call ap_rparam (out, KY_DANNULUS, dannulus, UN_SSCALEUNIT,
+	        "width of the sky annulus")
+	    call ap_rparam (out, KY_SKYSIGMA, skysigma, UN_NCOUNTS,
+	        "standard deviation of 1 sky pixel")
+	    call ap_rparam (out, KY_DATAMIN, datamin, UN_ACOUNTS,
+	        "minimum good data value")
+	    call ap_rparam (out, KY_DATAMAX, datamax, UN_ACOUNTS,
+	        "maximum good data value")
+	}
+
+	call sfree (sp)
+end
diff --git a/noao/digiphot/apphot/polyphot/apycoords.x b/noao/digiphot/apphot/polyphot/apycoords.x
new file mode 100644
index 00000000..0298b0f8
--- /dev/null
+++ b/noao/digiphot/apphot/polyphot/apycoords.x
@@ -0,0 +1,43 @@
+include	"../lib/polyphot.h"
+
+# AP_YCOORDS -- Procedure to fetch the next center coordinates for the polygon.
+
+int procedure ap_ycoords (cl, delim, xshift, yshift, stdin)
+
+int	cl	# coordinates file descriptor
+int	delim	# delimiter character
+real	xshift	# new x coordinate
+real	yshift	# new y coordinate
+int	stdin	# is cl STDIN?
+
+char	marker
+int	stat
+int	fscan(), nscan()
+
+begin
+	if (stdin == YES) {
+	    call printf ("Type object x and y coordinates (^D or^Z to end): ")
+		call flush (STDOUT)
+	}
+
+	stat = fscan (cl)
+	while (stat != EOF) {
+
+            call gargr (xshift)
+            call gargr (yshift)
+
+	    if (nscan() != 2) {
+		call reset_scan()
+		call gargc (marker)
+		if (int (marker) == delim)
+		    return (NEXT_POLYGON)
+		#else
+		    #return (NEXT_OBJECT)
+	    } else
+	        return (THIS_OBJECT)
+
+	    stat = fscan (cl)
+	}
+
+	return (stat)
+end
diff --git a/noao/digiphot/apphot/polyphot/apydraw.x b/noao/digiphot/apphot/polyphot/apydraw.x
new file mode 100644
index 00000000..aadcbed0
--- /dev/null
+++ b/noao/digiphot/apphot/polyphot/apydraw.x
@@ -0,0 +1,55 @@
+include "../lib/polyphot.h"
+
+# APYDRAW -- Procedure to draw polygons interactively on the  display.
+
+procedure ap_ydraw (py, im, cl, pl, ld, pd, id)
+
+pointer py			# pointer to apphot structure
+pointer	im			# theinput image descriptor
+int	cl			# coordinates file descriptor
+int	pl			# vertices list file descriptor
+int	ld			# coordinate list number
+int	pd			# polygon list number
+pointer	id			# pointer to image display stream
+
+int	req_num, prev_num, nvertices, delim
+pointer	sp, x, y
+int	ap_ynextobj()
+data	delim /';'/
+
+begin
+	# Allocate temporary space for arrays.
+	call smark (sp)
+	call salloc (x, MAX_NVERTICES + 1, TY_REAL)
+	call salloc (y, MAX_NVERTICES + 1, TY_REAL)
+
+	# Rewind the polygon and coordinate files.
+	if (pl != NULL)
+	    call seek (pl, BOF)
+	if (cl != NULL)
+	    call seek (cl, BOF)
+
+	# Initialize.
+	pd = 0
+	prev_num = 0
+	req_num = ld + 1
+	nvertices = ap_ynextobj (py, im, id, pl, cl, delim, Memr[x], Memr[y],
+	    MAX_NVERTICES, prev_num, req_num, ld, pd)
+
+	# Loop over the coordinate and polygon file.
+	while (nvertices != EOF) {
+	    
+	    # Draw the polygon if it has more than three vertices.
+	    if (id != NULL && nvertices >= 3)
+		call appymark (py, id, Memr[x], Memr[y], nvertices + 1,
+		    NO, NO, YES)
+
+	    # Setup for next polygon.
+	    prev_num = ld
+	    req_num = ld + 1
+	    nvertices = ap_ynextobj (py, im, id, pl, cl, delim, Memr[x],
+	        Memr[y], MAX_NVERTICES, prev_num, req_num, ld, pd)
+	}   
+
+	call sfree (sp)
+end
diff --git a/noao/digiphot/apphot/polyphot/apyfit.x b/noao/digiphot/apphot/polyphot/apyfit.x
new file mode 100644
index 00000000..abb76a6d
--- /dev/null
+++ b/noao/digiphot/apphot/polyphot/apyfit.x
@@ -0,0 +1,578 @@
+include <imhdr.h>
+include <mach.h>
+include "../lib/apphot.h"
+include "../lib/noise.h"
+include "../lib/polyphot.h"
+
+# AP_YFIT -- Procedure to compute the magnitude of an object inside a polygonal
+# aperture.
+
+int procedure ap_yfit (py, im, xver, yver, nver, skyval, skysig, nsky)
+
+pointer	py		# pointer to polyphot strucuture
+pointer	im		# pointer to IRAF image
+real	xver[ARB]	# x vertices coords
+real	yver[ARB]	# y vertices coords
+int	nver		# number of vertices
+real	skyval		# sky value
+real	skysig		# sigma of sky pixels
+int	nsky		# number of sky pixels
+
+double	flux, area
+int	noise, badpix, ier
+real	datamin, datamax, mag, magerr, zmag, padu, itime, readnoise
+int	apstati(), ap_yyfit(), ap_byyfit()
+real	apstatr()
+
+begin
+	# Initialize.
+	call apsetd (py, PYFLUX, 0.0d0)
+	call apsetd (py, PYNPIX, 0.0d0)
+	call apsetr (py, PYMAG, INDEFR)
+	call apsetr (py, PYMAGERR, INDEFR)
+
+	# Compute the flux inside the polygon.
+	if (IS_INDEFR(apstatr (py, DATAMIN)) && IS_INDEFR(apstatr(py,
+	    DATAMAX))) {
+	    ier = ap_yyfit (im, xver, yver, nver, flux, area)
+	    badpix = NO
+	} else {
+	    if (IS_INDEFR(apstatr (py, DATAMIN)))
+		datamin = -MAX_REAL
+	    else
+		datamin = apstatr (py, DATAMIN)
+	    if (IS_INDEFR(apstatr (py, DATAMAX)))
+		datamax = MAX_REAL
+	    else
+		datamax = apstatr (py, DATAMAX)
+	    ier = ap_byyfit (im, xver, yver, nver, datamin, datamax, flux,
+	        area, badpix)
+	}
+
+	if (ier == PY_NOPOLYGON)
+	    return (PY_NOPOLYGON)
+	else if (ier == PY_NOPIX)
+	    return (PY_NOPIX)
+
+	# Store the results.
+	call apsetd (py, PYFLUX, flux)
+	call apsetd (py, PYNPIX, area)
+	call apseti (py, PYBADPIX, badpix)
+
+	if (IS_INDEFR(skyval))
+	    return (PY_NOSKYMODE)
+
+	# Get the photometry parameters.
+	zmag = apstatr (py, PYZMAG)
+	itime = apstatr (py, ITIME)
+	noise = apstati (py, NOISEFUNCTION)
+	padu = apstatr (py, EPADU)
+	readnoise = apstatr (py, READNOISE)
+
+	# Compute the magnitude and error.
+	if (badpix == NO) {
+	    if (apstati (py, POSITIVE) == YES)
+	        call apcopmags (flux, area, mag, magerr, 1, skyval,
+		    skysig, nsky, zmag, noise, padu)
+	    else
+	        call apconmags (flux, area, mag, magerr, 1, skyval,
+		    skysig, nsky, zmag, noise, padu, readnoise)
+	    mag  = mag + 2.5 * log10 (itime)
+
+	    call apsetr (py, PYMAG, mag)
+	    call apsetr (py, PYMAGERR, magerr)
+	}
+
+	return (ier)
+end
+
+
+# AP_YYFIT -- Measure the total flux inside a polygon.
+
+int procedure ap_yyfit (im, xver, yver, nver, flux, area)
+
+pointer	im		# pointer to IRAF image
+real	xver[ARB]	# x coordinates of the vertices
+real	yver[ARB]	# y coordinates of the vertices:
+int	nver		# number of vertices
+double	flux		# flux interior to the polygon
+double	area		# approximate area of polygon
+
+double	fluxx, areax, fctnx, fctny
+real	xmin, xmax, ymin, ymax, x1, x2, lx, ld
+pointer	sp, work1, work2, xintr, buf
+int	i, j, k, linemin, linemax, colmin, colmax, nintr, ier
+int	ap_yclip()
+pointer	imgl2r()
+
+begin
+	# Check that polygon has at least 3 vertices plus the closing vertex.
+	if (nver < 4) {
+	    flux = INDEFD
+	    area = 0.0d0
+	    return (PY_NOPOLYGON)
+	}
+
+	# Allocate working space.
+	call smark (sp)
+	call salloc (work1, nver, TY_REAL)
+	call salloc (work2, nver, TY_REAL)
+	call salloc (xintr, nver, TY_REAL)
+
+	# Find the minimum and maximum x and y values of the polygon
+	# and detemine whether the polygon is partially off the image.
+
+	call alimr (xver, nver, xmin, xmax)
+	call alimr (yver, nver, ymin, ymax)
+	if (xmin < 0.5 || xmax > (IM_LEN(im,1) + 0.5) || ymin < 0.5 || ymax >
+	    (IM_LEN(im,2) + 0.5))
+	    ier = PY_OUTOFBOUNDS
+	else
+	    ier = PY_OK
+
+	# Find the minimum and maximum image line numbers.
+	ymin = max (0.5, min (real (IM_LEN (im,2) + 0.5), ymin))
+	ymax = min (real (IM_LEN(im,2) + 0.5), max (0.5, ymax))
+	linemin = min (int (ymin + 0.5), int (IM_LEN(im,2)))
+	linemax = min (int (ymax + 0.5), int (IM_LEN(im,2)))
+
+	# Set up the line segment parameters and initialize fluxes and areas.
+	x1 = 0.5
+	x2 = IM_LEN(im,1) + 0.5
+	lx = x2 - x1
+	flux = 0.0d0
+	area = 0.0d0
+
+	# Loop over the range of lines of interest.
+	do i = linemin, linemax {
+
+	    # Read in image line.
+	    buf = imgl2r (im, i)
+	    if (buf == EOF)
+		next
+
+	    # Find all the x intersection points of image line and polygon.
+	    if (ymin > i)
+		ld = min (i + 1, linemax)
+	    else if (ymax < i)
+		ld = max (i - 1, linemin)
+	    else
+	        ld = i
+	    nintr = ap_yclip (xver, yver, Memr[work1], Memr[work2],
+	        Memr[xintr],  nver, lx, ld)
+	    if (nintr <= 0)
+		next
+	    fctny = min (i + 0.5, ymax) - max (i - 0.5, ymin)
+
+	    # Sort the x intersection points
+	    call asrtr (Memr[xintr], Memr[xintr], nintr)
+
+	    # Integrate the flux in each line segment.
+	    fluxx = 0.0d0
+	    areax = 0.0d0
+	    do j = 1, nintr, 2 {
+
+		# Compute the line segment limits.
+		xmin = min (real (IM_LEN(im,1) + 0.5), max (0.5,
+		    Memr[xintr+j-1]))
+		xmax = min (real (IM_LEN(im,1) + 0.5), max (0.5,
+		    Memr[xintr+j]))
+		colmin = min (int (xmin + 0.5), int (IM_LEN(im,1)))
+		colmax = min (int (xmax + 0.5), int (IM_LEN(im,1)))
+
+		# Sum the contribution from a particular line segment.
+		do k = colmin, colmax {
+	            fctnx = min (k + 0.5, xmax) - max (k - 0.5, xmin)
+		    fluxx = fluxx + fctnx * Memr[buf+k-1]
+		    areax = areax + fctnx
+		}
+	    }
+
+	    # Add the line sum to the total.
+	    area = area + areax * fctny
+	    flux = flux + fluxx * fctny
+	}
+
+	call sfree (sp)
+
+	# Return the appropriate error code.
+	if (area <= 0.0d0)
+	    return (PY_NOPIX)
+	else if (ier != PY_OK)
+	    return (ier)
+	else
+	    return (PY_OK)
+end
+
+
+# AP_BYYFIT -- Measure the total flux inside a polygon while searching for
+# bad pixels at the same time.
+
+int procedure ap_byyfit (im, xver, yver, nver, datamin, datamax, flux, area,
+	badpix)
+
+pointer	im		# pointer to IRAF image
+real	xver[ARB]	# x coordinates of the vertices
+real	yver[ARB]	# y coordinates of the vertices:
+int	nver		# number of vertices
+real	datamin		# minimum good data value
+real	datamax		# maximum good data value
+double	flux		# flux interior to the polygon
+double	area		# approximate area of polygon
+int	badpix		# are there bad pixels
+
+int	i, j, k, linemin, linemax, colmin, colmax, nintr, ier
+pointer	sp, work1, work2, xintr, buf
+real	xmin, xmax, ymin, ymax, x1, x2, lx, ld
+double	fluxx, areax, fctnx, fctny
+int	ap_yclip()
+pointer	imgl2r()
+
+begin
+	# Check that polygon has at least 3 vertices plus a closing vertex.
+	if (nver < 4) {
+	    flux = INDEFD
+	    area = 0.0d0
+	    badpix = NO
+	    return (PY_NOPOLYGON)
+	}
+
+	# Allocate working space.
+	call smark (sp)
+	call salloc (work1, nver, TY_REAL)
+	call salloc (work2, nver, TY_REAL)
+	call salloc (xintr, nver, TY_REAL)
+
+	# Find minimum and maximum y values of the polygon vertices and
+	# compute the minimum and maximum image line limits.
+
+	call alimr (xver, nver, xmin, xmax)
+	call alimr (yver, nver, ymin, ymax)
+	if (xmin < 0.5 || xmax > (IM_LEN(im,1) + 0.5) || ymin < 0.5 || ymax >
+	    (IM_LEN(im,2) + 0.5))
+	    ier = PY_OUTOFBOUNDS
+	else
+	    ier = PY_OK
+
+	# Find the min and max image line numbers.
+	ymin = max (0.5, min (real (IM_LEN (im,2) + 0.5), ymin))
+	ymax = min (real (IM_LEN(im,2) + 0.5), max (0.5, ymax))
+	linemin = max (1, min (int (ymin + 0.5), int (IM_LEN(im,2))))
+	linemax = max (1, min (int (ymax + 0.5), int (IM_LEN(im,2))))
+
+	# Set up line segment parameters and initialize fluxes.
+	x1 = 0.5
+	x2 = IM_LEN(im,1) + 0.5
+	lx = x2 - x1
+	flux = 0.0d0
+	area = 0.0d0
+
+	# Loop over the range of lines of interest.
+	badpix = NO
+	do i = linemin, linemax {
+
+	    # Read in the image line.
+	    buf = imgl2r (im, i)
+	    if (buf == EOF)
+		next
+
+	    # Find all the intersection points.
+	    if (ymin > i)
+		ld = min (i + 1, linemax)
+	    else if (ymax < i)
+		ld = max (i - 1, linemin)
+	    else
+	        ld = i
+	    nintr = ap_yclip (xver, yver, Memr[work1], Memr[work2],
+	        Memr[xintr], nver, lx, ld)
+	    if (nintr <= 0)
+		next
+	    fctny = min (i + 0.5, ymax) - max (i - 0.5, ymin)
+
+	    # Sort the x intersection points
+	    call asrtr (Memr[xintr], Memr[xintr], nintr)
+
+	    # Integrate the flux in the line segment
+	    fluxx = 0.0d0
+	    areax = 0.0d0
+	    do j = 1, nintr, 2 {
+
+		# Compute the line segment limits.
+		xmin = min (real (IM_LEN(im,1) + 0.5), max (0.5,
+		    Memr[xintr+j-1]))
+		xmax = min (real (IM_LEN(im,1) + 0.5), max (0.5, Memr[xintr+j]))
+		colmin = min (int (xmin + 0.5), int (IM_LEN(im,1)))
+		colmax = min (int (xmax + 0.5), int (IM_LEN(im,1)))
+
+		# Sum the contribution from a particular line segment.
+		do k = colmin, colmax {
+	            fctnx = min (k + 0.5, xmax) - max (k - 0.5, xmin)
+		    fluxx = fluxx + fctnx * Memr[buf+k-1]
+		    areax = areax + fctnx
+		    if (Memr[buf+k-1] < datamin || Memr[buf+k-1] > datamax)
+			badpix = YES
+		}
+	    }
+
+	    # Add the line sum to the total.
+	    area = area + areax * fctny
+	    flux = flux + fluxx * fctny
+	}
+
+	call sfree (sp)
+
+	if (area <= 0.0d0)
+	    return (PY_NOPIX)
+	if (badpix == YES)
+	    return (PY_BADDATA)
+	else if (ier != PY_OK)
+	    return (ier)
+	else
+	    return (PY_OK)
+end
+
+
+# AP_YCLIP -- Compute the intersection of an image line with a polygon defined
+# by a list of vertices.  The output is a list of ranges stored in the array
+# xranges. Two work additional work arrays xintr and slope are required for
+# the computation.
+
+int procedure ap_yclip (xver, yver, xintr, slope, xranges, nver, lx, ld)
+
+real	xver[ARB]		# x vertex coords
+real	yver[ARB]		# y vertex coords
+real	xintr[ARB]		# work array of x intersection points
+real	slope[ARB]		# work array of y slopes at intersection points
+real	xranges[ARB]		# x line segments
+int	nver			# number of vertices
+real	lx, ld 			# equation of image line
+
+bool	collinear
+int	i, j, nintr, nplus, nzero, nneg, imin, imax, nadd
+real	u1, u2, u1u2, dx, dy, dd, xa, wa
+
+begin
+	# Compute the intersection points of the image line and the polygon.
+	collinear = false
+	nplus = 0
+	nzero = 0
+	nneg = 0
+	nintr = 0
+	#u1 = - lx * yver[1] + ld
+	u1 = lx * (- yver[1] + ld)
+	do i = 2, nver {
+
+	    #u2 = - lx * yver[i] + ld
+	    u2 = lx * (- yver[i] + ld)
+	    u1u2 = u1 * u2
+
+	    # Does the polygon side intersect the image line ?
+	    if (u1u2 <= 0.0) {
+
+
+		# Compute the x intersection coordinate if the point of
+		# intersection is not a vertex.
+
+		if ((u1 != 0.0) && (u2 != 0.0)) {
+
+		    dy = yver[i-1] - yver[i]
+		    dx = xver[i-1] - xver[i]
+		    dd = xver[i-1] * yver[i] - yver[i-1] * xver[i]
+		    #xa = (dx * ld - lx * dd)
+		    xa = lx * (dx * ld - dd)
+		    wa = dy * lx
+		    nintr = nintr + 1
+		    xranges[nintr] = xa / wa
+		    slope[nintr] = -dy
+		    if (slope[nintr] < 0.0)
+			nneg = nneg + 1
+		    else if (slope[nintr] > 0.0)
+			nplus = nplus + 1
+		    else
+			nzero = nzero + 1
+		    collinear = false
+
+		# For each collinear line segment add two intersection
+		# points. Remove interior collinear intersection points.
+
+		} else if (u1 == 0.0 && u2 == 0.0) {
+
+		    if (! collinear) {
+		        nintr = nintr + 1
+			xranges[nintr] = xver[i-1]
+			if (i == 2)
+			    slope[nintr] = yver[1] - yver[nver-1]
+			else
+			    slope[nintr] = yver[i-1] - yver[i-2]
+		        if (slope[nintr] < 0.0)
+			    nneg = nneg + 1
+		        else if (slope[nintr] > 0.0)
+			    nplus = nplus + 1
+		        else
+			    nzero = nzero + 1
+		        nintr = nintr + 1
+		        xranges[nintr] = xver[i]
+			slope[nintr] = 0.0
+			nzero = nzero + 1
+		    } else {
+		        xranges[nintr] = xver[i]
+			slope[nintr] = 0.0
+			nzero = nzero + 1
+		    }
+		    collinear = true
+
+		# If the intersection point is a vertex add it to the
+		# list if it is not collinear with the next point. Add
+		# another point to the list if the vertex is at the
+		# apex of an acute angle.
+
+		} else if (u1 != 0.0) {
+
+		    if (i == nver) {
+		        dx = (xver[2] - xver[nver])
+			dy = (yver[2] - yver[nver])
+			dd = dy * (yver[nver-1] - yver[nver])
+		    } else {
+			dx = (xver[i+1] - xver[i])
+			dy = (yver[i+1] - yver[i])
+			dd = dy * (yver[i-1] - yver[i])
+		    }
+
+		    # Test whether the point is collinear with the point
+		    # ahead. If it is not include the intersection point. 
+
+		    if (dy != 0.0) {
+			nintr = nintr + 1
+			xranges[nintr] = xver[i]
+			slope[nintr] = yver[i] - yver[i-1]
+		        if (slope[nintr] < 0.0)
+			    nneg = nneg + 1
+		        else if (slope[nintr] > 0.0)
+		            nplus = nplus + 1
+		        else
+			    nzero = nzero + 1
+		    }
+
+		    # If the intersection point is an isolated vertex add
+		    # another point to the list.
+
+		    if (dd > 0.0) {
+			nintr = nintr + 1
+			xranges[nintr] = xver[i]
+			slope[nintr] = dy
+		        if (slope[nintr] < 0.0)
+			    nneg = nneg + 1
+		        else if (slope[nintr] > 0.0)
+		            nplus = nplus + 1
+		        else
+			    nzero = nzero + 1
+		    }
+
+		    collinear = false
+
+		} else
+		    collinear = false
+	    } else
+		collinear = false
+
+	    u1 = u2
+	}
+
+	# Join up any split collinear line segments.
+	if (collinear && (slope[1] == 0.0)) {
+	    xranges[1] = xranges[nintr-1]
+	    slope[1] = slope[nintr-1]
+	    nintr = nintr - 2
+	    nzero = nzero - 2
+	}
+
+	# Return the number of intersection points if there are no interior
+	# collinear line segments.
+	if (nzero == 0 || nplus == 0 || nneg == 0)
+	    return (nintr)
+
+	# Find the minimum and maximum intersection points.
+	call ap_alimr (xranges, nintr, u1, u2, imin, imax)
+
+	# Check for vertices at the ends of the ranges.
+
+	u1 = xranges[min(imin,imax)] - xranges[1]
+	u2 = xranges[nintr] - xranges[max(imin,imax)]
+
+	# Vertices were traversed in order of increasing x.
+	if ((u1 >= 0.0 && u2 > 0.0) || (u1 > 0.0 && u2 >= 0.0) ||
+	    (u1 == u2 && imax > imin)) {
+	    do i = imax + 1, nintr {
+		if (xranges[i] != xranges[i-1])
+		    break
+		imax = i
+	    }
+	    do i = imin - 1, 1, -1 {
+		if (xranges[i] != xranges[i+1])
+		    break
+		imin = i
+	    }
+	}
+
+	# Vertices were traversed in order of decreasing x.
+	if ((u1 <= 0.0 && u2 < 0.0) || (u1 < 0.0 && u2 <= 0.0) || 
+	    (u1 == u2 && imax < imin)) {
+	    do i = imin + 1, nintr {
+		if (xranges[i] != xranges[i-1])
+		    break
+		imin = i
+	    }
+	    do i = imax - 1, 1, -1 {
+		if (xranges[i] != xranges[i+1])
+		    break
+		imax = i
+	    }
+	}
+
+	# Reorder the x ranges and slopes if necessary. 
+	if ((imax < imin) && ! (imin == nintr && imax == 1)) {
+	    call amovr (xranges, xintr, nintr)
+	    do i = 1, imax
+	        xranges[nintr-imax+i] = xintr[i]
+	    do i = imin, nintr
+	        xranges[i-imax] = xintr[i]
+	    call amovr (slope, xintr, nintr)
+	    do i = 1, imax
+	        slope[nintr-imax+i] = xintr[i]
+	    do i = imin, nintr
+	        slope[i-imax] = xintr[i]
+	} else if ((imin < imax) && ! (imin == 1 && imax == nintr)) {
+	    call amovr (xranges, xintr, nintr)
+	    do i = 1, imin
+		xranges[nintr-imin+i] = xintr[i]
+	    do i = imax, nintr
+		xranges[i-imin] = xintr[i]
+	    call amovr (slope, xintr, nintr)
+	    do i = 1, imin
+		slope[nintr-imin+i] = xintr[i]
+	    do i = imax, nintr
+		slope[i-imin] = xintr[i]
+	}
+
+	# Add any extra intersection points that are required to deal with
+	# the collinear line segments.
+
+	nadd = 0
+	for (i = 1; i <= nintr-2; ) {
+	    if (slope[i] * slope[i+2] > 0.0) {
+		i = i + 2
+	    } else {
+		nadd = nadd + 1
+		xranges[nintr+nadd] = xranges[i+1]
+		for (j = i + 3; j <= nintr; j = j + 1) {
+		    if (slope[i] * slope[j] > 0)
+			break
+		    nadd = nadd + 1
+		    xranges[nintr+nadd] = xranges[j-1]
+		}
+		i = j
+	    }
+	}
+
+	return (nintr + nadd)
+end
diff --git a/noao/digiphot/apphot/polyphot/apyfree.x b/noao/digiphot/apphot/polyphot/apyfree.x
new file mode 100644
index 00000000..0bede579
--- /dev/null
+++ b/noao/digiphot/apphot/polyphot/apyfree.x
@@ -0,0 +1,41 @@
+include "../lib/apphotdef.h"
+include "../lib/polyphotdef.h"
+
+# AP_YFREE -- Procedure to free the polyphot structure.
+
+procedure ap_yfree (ap)
+
+pointer	ap		# pointer to the apphot structure
+
+begin
+	if (ap == NULL)
+	    return
+	if (AP_NOISE(ap) != NULL)
+	    call ap_noisecls (ap)
+	if (AP_PDISPLAY(ap) != NULL)
+	    call ap_dispcls (ap)
+	if (AP_POLY(ap) != NULL)
+	    call ap_ycls (ap)
+	if (AP_PSKY(ap) != NULL)
+	    call ap_skycls (ap)
+	if (AP_PCENTER(ap) != NULL)
+	    call ap_ctrcls (ap)
+	if (AP_IMBUF(ap) != NULL)
+	    call mfree (AP_IMBUF(ap), TY_REAL)
+	if (AP_MW(ap) != NULL)
+	    call mw_close (AP_MW(ap))
+	call mfree (ap, TY_STRUCT)
+end
+
+
+# AP_YCLS -- Procedure to close up the polyphot structure and arrays.
+
+procedure ap_ycls (ap)
+
+pointer	ap		# pointer to the apphot structure
+
+begin
+	if (AP_POLY(ap) == NULL)
+	    return
+	call mfree (AP_POLY(ap), TY_STRUCT)
+end
diff --git a/noao/digiphot/apphot/polyphot/apyget.x b/noao/digiphot/apphot/polyphot/apyget.x
new file mode 100644
index 00000000..a990b6f8
--- /dev/null
+++ b/noao/digiphot/apphot/polyphot/apyget.x
@@ -0,0 +1,306 @@
+include <fset.h>
+include "../lib/apphot.h"
+include "../lib/fitsky.h"
+include "../lib/polyphot.h"
+
+# AP_YGET -- Procedure to fetch the coordinates of the vertices of a
+# polygon from a text file.
+
+int procedure ap_yget (py, im, fd, delim, x, y, max_nvertices)
+
+pointer	py		# polyphot structure
+pointer	im		# the input image descriptor
+int	fd		# polygon file descriptor
+int	delim		# delimiter character
+real	x[ARB]		# x coords of vertices
+real	y[ARB]		# y coords of vertices
+int	max_nvertices	# maximum number of vertices
+
+real	xc, yc, r2max, r2, xtemp, ytemp
+pointer	sp, str
+int	i, nvertices, nreal, stat
+char	marker
+real	asumr()
+int	fscan(), nscan(), strncmp(), apstati()
+
+begin
+	call smark (sp)
+	call salloc (str, SZ_LINE, TY_CHAR)
+
+	# Print prompts if input file is STDIN.
+	call fstats (fd, F_FILENAME, Memc[str], SZ_LINE)
+	if (strncmp ("STDIN", Memc[str], 5) == 0) {
+	    call printf ("Type x and y coordinates of vertex\n")
+	    call printf ("\t1 vertex per line\n")
+	    call printf ("\t; to end polygon\n")
+	    call printf ("\t^Z to end list\n")
+	    call flush (STDOUT)
+	}
+
+	# Get the polygon.
+	nvertices = 0
+	stat = fscan (fd)
+	while (stat != EOF) {
+
+	    # Read the vertices from the file
+	    call gargr (xtemp)
+	    call gargr (ytemp)
+	    nreal = nscan ()
+	    if (nreal != 2) {
+		call reset_scan ()
+		call gargc (marker)
+		if (int (marker) == delim)
+		    break
+		nreal = nscan ()
+	    }
+
+	    # Store the vertices.
+	    if (nreal >= 2) {
+	        nvertices = nvertices + 1
+	        if (nvertices <= max_nvertices) {
+		    x[nvertices] = xtemp
+		    y[nvertices] = ytemp
+	        }
+	    }
+
+	    stat = fscan (fd)
+	}
+
+	if (nvertices == 0 && stat == EOF) {
+
+	    nvertices = EOF
+	    call apsetr (py, PYXMEAN, INDEFR)
+	    call apsetr (py, PYYMEAN, INDEFR)
+	    call apsetr (py, OPYXMEAN, INDEFR)
+	    call apsetr (py, OPYYMEAN, INDEFR)
+	    call apsetr (py, PYCX, INDEFR)
+	    call apsetr (py, PYCY, INDEFR)
+	    call apsetr (py, OPYCX, INDEFR)
+	    call apsetr (py, OPYCY, INDEFR)
+	    call apsetr (py, PYMINRAD, INDEFR)
+	    call apseti (py, PYNVER, 0)
+
+	} else if (nvertices <= 2) {
+
+	    call apsetr (py, PYXMEAN, INDEFR)
+	    call apsetr (py, PYYMEAN, INDEFR)
+	    call apsetr (py, OPYXMEAN, INDEFR)
+	    call apsetr (py, OPYYMEAN, INDEFR)
+	    call apsetr (py, PYCX, INDEFR)
+	    call apsetr (py, PYCY, INDEFR)
+	    call apsetr (py, OPYCX, INDEFR)
+	    call apsetr (py, OPYCY, INDEFR)
+	    call apsetr (py, PYMINRAD, INDEFR)
+	    call apseti (py, PYNVER, 0)
+	    nvertices = 0
+
+	} else {
+
+	    # Add in the last vertex.
+	    x[nvertices+1] = x[1]
+	    y[nvertices+1] = y[1]
+
+            # Transform the input coordinates.
+            switch (apstati(py,WCSIN)) {
+            case WCS_WORLD, WCS_PHYSICAL:
+                call ap_itol (py, x, y, x, y, nvertices + 1)
+            case WCS_TV:
+                call ap_vtol (im, x, y, x, y, nvertices + 1)
+            default:
+                ;
+            }
+
+	    # Compute the mean polygon coordinates.
+	    xc = asumr (x, nvertices) / nvertices
+	    yc = asumr (y, nvertices) / nvertices
+	    call apsetr (py, PYXMEAN, xc)
+	    call apsetr (py, PYYMEAN, yc)
+	    call apsetr (py, PYCX, xc)
+	    call apsetr (py, PYCY, yc)
+
+	    # Set the minimum size of the sky annulus.
+	    r2max = 0.0
+	    do i = 1, nvertices {
+		r2 = (x[i] - xc) ** 2 + (y[i] - yc) ** 2
+		if (r2 > r2max)
+		    r2max = r2
+	    }
+
+            switch (apstati(py,WCSOUT)) {
+            case WCS_WORLD, WCS_PHYSICAL:
+                call ap_ltoo (py, xc, yc, xc, yc, 1)
+            case WCS_TV:
+                call ap_ltov (im, xc, yc, xc, yc, 1)
+            default:
+    		;
+	    }
+	    call apsetr (py, OPYXMEAN, xc)
+	    call apsetr (py, OPYYMEAN, yc)
+	    call apsetr (py, OPYCX, xc)
+	    call apsetr (py, OPYCY, yc)
+
+	    call apsetr (py, PYMINRAD, (sqrt (r2max) + 1.1))
+	    call apseti (py, PYNVER, nvertices)
+	}
+
+	call sfree (sp)
+	return (nvertices)
+end
+
+
+# AP_YMKPOLY -- Mark the coordinates of a polygon on the display device.
+
+int procedure ap_ymkpoly (py, im, id, x, y, max_nvertices, idflush)
+
+pointer	py		# polyphot structure
+pointer	im		# the input image descriptor
+pointer	id		# display pointer
+real	x[ARB]		# x coords of vertices
+real	y[ARB]		# y coords of vertices
+int	max_nvertices	# maximum number of vertices
+int	idflush		# flush the imd interface ?
+
+int	i, nvertices, stat, wcs, key
+pointer	sp, cmd
+real	xtemp, ytemp, xc, yc, r2max, r2
+real	apstatr(), asumr()
+int	clgcur(), apstati()
+errchk	gscur
+
+begin
+	# Reopen the device.
+	if (id != NULL)
+	    call greactivate (id, 0)
+
+	# Initialize.
+	call smark (sp)
+	call salloc (cmd, SZ_LINE, TY_CHAR)
+
+	# Type prompt.
+	call printf (
+	    "Mark polygon vertex [space=mark,q=quit].\n")
+	stat = clgcur ("icommands", xtemp, ytemp, wcs, key, Memc[cmd], SZ_LINE)
+	call ap_vtol (im, xtemp, ytemp, xtemp, ytemp, 1)
+
+
+	# Fetch the polygon and draw it on the display.
+	nvertices = 0
+	while (stat != EOF) {
+
+	    if (key == 'q')
+		break
+
+	    # Decode and draw vertices.
+	    nvertices = nvertices + 1
+	    if (nvertices <= max_nvertices) {
+		x[nvertices] = xtemp
+		y[nvertices] = ytemp
+		if (id != NULL) {
+		    if (nvertices == 1)
+		        call gamove (id, x[1], y[1])
+		    else {
+		        call gadraw (id, x[nvertices], y[nvertices])
+			if (idflush == YES)
+			    call gframe (id)
+			else
+			    call gflush (id)
+		    }
+		}
+	    } else
+		break
+
+	    # Type prompt.
+	    call printf (
+	        "Mark polygon vertex [space=mark,q=quit].\n")
+	    stat = clgcur ("icommands", xtemp, ytemp, wcs, key, Memc[cmd],
+	        SZ_LINE)
+	    call ap_vtol (im, xtemp, ytemp, xtemp, ytemp, 1)
+	}
+	call printf ("\n")
+
+	call sfree (sp)
+
+	# Return EOF or the number of vertices in the polygon.
+	if (stat == EOF) {
+
+	    call apsetr (py, PYXMEAN, INDEFR)
+	    call apsetr (py, PYYMEAN, INDEFR)
+	    call apsetr (py, OPYXMEAN, INDEFR)
+	    call apsetr (py, OPYYMEAN, INDEFR)
+	    call apsetr (py, PYCX, INDEFR)
+	    call apsetr (py, PYCY, INDEFR)
+	    call apsetr (py, OPYCX, INDEFR)
+	    call apsetr (py, OPYCY, INDEFR)
+	    call apsetr (py, PYMINRAD, INDEFR)
+	    call apseti (py, PYNVER, 0)
+	    nvertices = EOF
+
+	} else if (nvertices  <= 2) {
+
+	    call apsetr (py, PYXMEAN, INDEFR)
+	    call apsetr (py, PYYMEAN, INDEFR)
+	    call apsetr (py, OPYXMEAN, INDEFR)
+	    call apsetr (py, OPYYMEAN, INDEFR)
+	    call apsetr (py, PYCX, INDEFR)
+	    call apsetr (py, PYCY, INDEFR)
+	    call apsetr (py, OPYCX, INDEFR)
+	    call apsetr (py, OPYCY, INDEFR)
+	    call apsetr (py, PYMINRAD, INDEFR)
+	    call apseti (py, PYNVER, 0)
+	    nvertices = 0
+
+	} else {
+
+	    # Add the last vertex and close the polygon.
+	    x[nvertices+1] = x[1]
+	    y[nvertices+1] = y[1]
+	    if (id != NULL) {
+	        call gadraw (id, x[1], y[1])
+		if (idflush == YES)
+		    call gframe (id)
+		else
+	            call gflush (id)
+	    }
+
+	    # Compute and save the mean polygon coords.
+	    xc = asumr (x, nvertices) / nvertices
+	    yc = asumr (y, nvertices) / nvertices
+	    call apsetr (py, PYXMEAN, xc)
+	    call apsetr (py, PYYMEAN, yc)
+	    call apsetr (py, PYCX, xc)
+	    call apsetr (py, PYCY, yc)
+	    if (id != NULL)
+	        call gscur (id, apstatr (py, PYCX), apstatr (py, PYCY))
+
+	    # Compute the mean sky annulus.
+	    r2max = 0.0
+	    do i = 1, nvertices {
+		r2 = (x[i] - xc) ** 2 + (y[i] - yc) ** 2
+		if (r2 > r2max)
+		    r2max = r2
+	    }
+
+	    # Compute output coordinate centers.
+            switch (apstati(py,WCSOUT)) {
+            case WCS_WORLD, WCS_PHYSICAL:
+                call ap_ltoo (py, xc, yc, xc, yc, 1)
+            case WCS_TV:
+                call ap_ltov (im, xc, yc, xc, yc, 1)
+            default:
+                ;
+            }
+            call apsetr (py, OPYXMEAN, xc)
+            call apsetr (py, OPYYMEAN, yc)
+            call apsetr (py, OPYCX, xc)
+            call apsetr (py, OPYCY, yc)
+
+	    call apseti (py, PYNVER, nvertices)
+	    call apsetr (py, PYMINRAD, (sqrt (r2max) + 1.1))
+
+	}
+
+	if (id != NULL)
+	    call gdeactivate (id, 0)
+
+	return (nvertices)
+end
diff --git a/noao/digiphot/apphot/polyphot/apyinit.x b/noao/digiphot/apphot/polyphot/apyinit.x
new file mode 100644
index 00000000..6d9c2fe7
--- /dev/null
+++ b/noao/digiphot/apphot/polyphot/apyinit.x
@@ -0,0 +1,64 @@
+include "../lib/apphotdef.h"
+include "../lib/polyphotdef.h"
+
+# AP_YINIT - Initialize the polyphot structure.
+
+procedure ap_yinit (ap, cfunction, cbox, sfunction, annulus, dannulus, fwhmpsf,
+    noise)
+
+pointer	ap		# pointer to the apphot structure
+int	cfunction	# centering algorithm
+real	cbox		# centering box half-width
+int	sfunction	# sky fitting algorithm
+real	annulus		# inner radius of sky annulus
+real	dannulus	# width of sky annulus
+real	fwhmpsf		# fwhmpsf
+int	noise		# Noise function
+
+begin
+	call malloc (ap, LEN_APSTRUCT, TY_STRUCT)
+
+	# Set the global apphot package parameters.
+	call ap_defsetup (ap, fwhmpsf)
+
+	# Setup noise parameters.
+	call ap_noisesetup (ap, noise)
+
+	# Set display options.
+	call ap_dispsetup (ap)
+
+	# Setup the centering parameters.
+	call ap_ctrsetup (ap, cfunction, cbox)
+
+	# Set up the sky fitting parameters.
+	call ap_skysetup (ap, sfunction, annulus, dannulus)
+
+	# Setup the polyphot parameters.
+	call ap_ysetup (ap)
+
+	# Set unused structure pointers to null.
+	AP_PPSF(ap) = NULL
+	AP_PPHOT(ap) = NULL
+	AP_RPROF(ap) = NULL
+end
+
+
+# AP_YSETUP -- Procedure to set parameters for polygonal aperture  photometry.
+
+procedure ap_ysetup (ap)
+
+pointer	ap		# pointer to apphot strucuture
+
+pointer	ply
+
+begin
+	call malloc (AP_POLY(ap), LEN_PYSTRUCT, TY_STRUCT)
+	ply = AP_POLY(ap)
+	AP_PYCX(ply) = INDEFR
+	AP_PYCY(ply) = INDEFR
+	AP_PYX(ply) = INDEFR
+	AP_PYY(ply) = INDEFR
+	AP_PYZMAG(ply) = DEF_PYZMAG
+	AP_PYNAME(ply) = EOS
+	AP_PYROOT(ply) = EOS
+end
diff --git a/noao/digiphot/apphot/polyphot/apymkfree.x b/noao/digiphot/apphot/polyphot/apymkfree.x
new file mode 100644
index 00000000..424b94e3
--- /dev/null
+++ b/noao/digiphot/apphot/polyphot/apymkfree.x
@@ -0,0 +1,23 @@
+include "../lib/apphotdef.h"
+
+# AP_YMKFREE -- Procedure to free the polyphot structure.
+
+procedure ap_ymkfree (ap)
+
+pointer	ap		# pointer to the apphot structure
+
+begin
+	if (ap == NULL)
+	    return
+	if (AP_NOISE(ap) != NULL)
+	    call ap_noisecls (ap)
+	if (AP_PDISPLAY(ap) != NULL)
+	    call ap_dispcls (ap)
+	if (AP_POLY(ap) != NULL)
+	    call ap_ycls (ap)
+	if (AP_IMBUF(ap) != NULL)
+	    call mfree (AP_IMBUF(ap), TY_REAL)
+	if (AP_MW(ap) != NULL)
+	    call mw_close (AP_MW(ap))
+	call mfree (ap, TY_STRUCT)
+end
diff --git a/noao/digiphot/apphot/polyphot/apymkinit.x b/noao/digiphot/apphot/polyphot/apymkinit.x
new file mode 100644
index 00000000..215d3e9c
--- /dev/null
+++ b/noao/digiphot/apphot/polyphot/apymkinit.x
@@ -0,0 +1,31 @@
+include "../lib/apphotdef.h"
+include "../lib/noise.h"
+
+# AP_YMKINIT - Procedure to initialize the polymark structure.
+
+procedure ap_ymkinit (ap)
+
+pointer	ap		# pointer to the apphot structure
+
+begin
+	call calloc (ap, LEN_APSTRUCT, TY_STRUCT)
+
+	# Set the main structure parameters.
+	call ap_defsetup (ap, 2.5)
+
+	# Set the noise options.
+	call ap_noisesetup (ap, AP_NPOISSON)
+
+	# Set display options.
+	call ap_dispsetup (ap)
+
+	# Setup the polyphot parameters.
+	call ap_ysetup (ap)
+
+	# Set unused structure pointers to null.
+	AP_PCENTER(ap) = NULL
+	AP_PSKY(ap) = NULL
+	AP_PPHOT(ap) = NULL
+	AP_RPROF(ap) = NULL
+	AP_PPSF(ap) = NULL
+end
diff --git a/noao/digiphot/apphot/polyphot/apynextobj.x b/noao/digiphot/apphot/polyphot/apynextobj.x
new file mode 100644
index 00000000..292d84bd
--- /dev/null
+++ b/noao/digiphot/apphot/polyphot/apynextobj.x
@@ -0,0 +1,190 @@
+include <fset.h>
+include "../lib/apphot.h"
+include "../lib/polyphot.h"
+
+# AP_YNEXTOBJ -- Read the next polygon from the list polygon and/or coordinate
+# list.
+
+int procedure ap_ynextobj (py, im, id, pl, cl, delim, x, y, maxnver, prev_num,
+    req_num, ld, pd)
+
+pointer	py		# pointer to the apphot structre
+pointer	im		# the input image descriptor
+pointer	id		# pointer to image display stream
+int	pl		# polygons file descriptor
+int	cl		# coordinates file descriptor
+int	delim		# delimiter character
+real	x[ARB]		# x coordinates of the polygon vertices
+real	y[ARB]		# y coordinates of the polygon vertices
+int	maxnver		# maximum number of vertices
+int	prev_num	# previous object
+int	req_num		# requested object
+int	ld		# current object
+int	pd		# current polygon
+
+real	xshift, yshift
+pointer	sp, fname
+int	stdin, nskip, ncount, nver, stat
+real	apstatr()
+int	strncmp(), ap_yget(), ap_ycoords(), apstati()
+errchk	greactivate, gdeactivate, gscur
+
+begin
+	# The coordinate list is undefined.
+	if (cl == NULL) {
+
+	    # Get the input file name.
+	    call smark (sp)
+	    call salloc (fname, SZ_FNAME, TY_CHAR)
+	    call fstats (pl, F_FILENAME, Memc[fname], SZ_FNAME)
+
+	    # Compute the number of polygons that must be skipped.
+	    if (strncmp ("STDIN", Memc[fname], 5) == 0) {
+		stdin = YES
+		nskip = 1
+	    } else {
+		stdin = NO
+		if (req_num <= prev_num) {
+		    call seek (pl, BOF)
+		    nskip = req_num
+		} else
+		    nskip = req_num - prev_num
+	    }
+
+	    # Initialize the polygon search.
+	    ncount = 0
+	    pd = prev_num
+
+	    # Find the correct polygon.
+	    repeat {
+
+		call apsetr (py, PYX, apstatr (py, PYCX))
+		call apsetr (py, PYY, apstatr (py, PYCY))
+		nver = ap_yget (py, im, pl, delim, x, y, maxnver)
+
+		if (nver == EOF) {
+		    ncount = EOF
+		}  else if (nver > 0) {
+		    ncount = ncount + 1
+		    pd = pd + 1
+		}
+
+	    } until (ncount == EOF || ncount == nskip)
+
+	    # Return the polygon number.
+	    if (req_num <= prev_num)
+		pd = ncount 
+	    ld = pd
+
+	    call sfree (sp)
+
+	    if (ncount == EOF) {
+		return (EOF)
+	    } else if (id != NULL) {
+		iferr {
+		    call greactivate (id, 0)
+		    call gscur (id, apstatr (py, PYCX), apstatr (py, PYCY))
+		    call gdeactivate (id, 0)
+		} then
+		    ;
+		return (nver)
+	     } else {
+		return (nver)
+	    }
+
+	# Both the polygon and coordinate file are defined.
+	} else {
+
+	    # Get the input file name.
+	    call smark (sp)
+	    call salloc (fname, SZ_FNAME, TY_CHAR)
+	    call fstats (cl, F_FILENAME, Memc[fname], SZ_FNAME)
+
+	    # Compute the number of objects that must be skipped.
+	    if (strncmp ("STDIN", Memc[fname], 5) == 0) {
+		stdin = YES
+		nskip = 1
+	    } else {
+		stdin = NO
+		if (req_num <= prev_num) {
+		    call seek (cl, BOF)
+		    call seek (pl, BOF)
+		    pd = 0
+		    nskip = req_num
+		} else
+		    nskip = req_num - prev_num
+	    }
+
+	    # Initialize the polygon id.
+	    ncount = 0
+	    ld = prev_num
+
+	    # Find the correct object and shift the coordinates.
+	    repeat {
+
+		# Read the coordinates and the polygon.
+		stat = ap_ycoords (cl, delim, xshift, yshift, stdin)
+		if (stat == EOF) {
+		    ncount = EOF
+		} else if (stat == NEXT_POLYGON || pd == 0) {
+		    call apsetr (py, PYX, apstatr (py, PYCX))
+		    call apsetr (py, PYY, apstatr (py, PYCY))
+		    nver = ap_yget (py, im, pl, delim, x, y, maxnver)
+		    if (nver == EOF)
+		        ncount = EOF
+		    else if (nver > 0)
+		        pd = pd + 1
+		}
+
+		# Shift the polygon coordinates.
+		if (stat == THIS_OBJECT && ncount != EOF && nver > 0) {
+            	    switch (apstati(py,WCSIN)) {
+            	    case WCS_WORLD, WCS_PHYSICAL:
+                	call ap_itol (py, xshift, yshift, xshift, yshift, 1)
+            	    case WCS_TV:
+                	call ap_vtol (im, xshift, yshift, xshift, yshift, 1)
+            	    default:
+                	;
+            	    }
+		    call aaddkr (x, (xshift - apstatr (py, PYCX)), x, nver + 1)
+		    call aaddkr (y, (yshift - apstatr (py, PYCY)), y, nver + 1)
+		    call apsetr (py, PYCX, xshift)
+		    call apsetr (py, PYCY, yshift)
+                    switch (apstati(py,WCSOUT)) {
+            	    case WCS_WORLD, WCS_PHYSICAL:
+                	call ap_ltoo (py, xshift, yshift, xshift, yshift, 1)
+            	    case WCS_TV:
+                	call ap_ltov (im, xshift, yshift, xshift, yshift, 1)
+            	    default:
+    			;
+            	    }
+		    call apsetr (py, OPYCX, xshift)
+		    call apsetr (py, OPYCY, yshift)
+		    ncount = ncount + 1
+		    ld = ld + 1
+		}
+
+	    } until (ncount == EOF || ncount == nskip)
+
+	    # Get the correct id.
+	    if (req_num <= prev_num)
+		ld = ncount
+
+	    call sfree (sp)
+
+	    if (ncount == EOF) {
+		return (EOF)
+	    } else if (id != NULL) {
+		iferr {
+		    call greactivate (id, 0)
+		    call gscur (id, apstatr (py, PYCX), apstatr (py, PYCY))
+		    call gdeactivate (id, 0)
+		} then
+		    ;
+		return (nver)
+	    } else {
+		return (nver)
+	    }
+	}
+
+end
diff --git a/noao/digiphot/apphot/polyphot/apypars.x b/noao/digiphot/apphot/polyphot/apypars.x
new file mode 100644
index 00000000..4f988323
--- /dev/null
+++ b/noao/digiphot/apphot/polyphot/apypars.x
@@ -0,0 +1,20 @@
+# AP_PYPARS -- Procedure to write the current polyphot parameters to the
+# output file.
+
+procedure ap_pypars (ap)
+
+pointer	ap		# pointer to apphot structure
+
+begin
+	# Write the data dependent parameters.
+	call ap_dapars (ap)
+
+	# Write the centering parameters.
+	call ap_cepars (ap)
+
+	# Write the sky fitting parameters.
+	call ap_sapars (ap)
+
+	# Set the photometry parameters.
+	call ap_popars (ap)
+end
diff --git a/noao/digiphot/apphot/polyphot/apyphot.x b/noao/digiphot/apphot/polyphot/apyphot.x
new file mode 100644
index 00000000..cd7bac0a
--- /dev/null
+++ b/noao/digiphot/apphot/polyphot/apyphot.x
@@ -0,0 +1,577 @@
+include <ctype.h>
+include <gset.h>
+include <imhdr.h>
+include "../lib/apphot.h"
+include "../lib/display.h"
+include "../lib/fitsky.h"
+include "../lib/polyphot.h"
+
+define	HELPFILE	"apphot$polyphot/polyphot.key"
+
+# AP_YPHOT -- Compute the flux inside polygonal apertures.
+
+int procedure ap_yphot (py, im, cl, pl, gd, id, out, stid, interactive, cache)
+
+pointer py		# pointer to apphot structure
+pointer	im		# pointer to IRAF image
+int	cl		# coordinate file descriptor
+int	pl		# starlist file descriptor
+pointer	gd		# pointer to graphcis stream
+pointer	id		# pointer to image display stream
+int	out		# output file descriptor
+int	stid		# output file sequence number
+int	interactive	# interactive mode
+int	cache		# cache the input image pixels
+
+real	wx, wy
+pointer	sp, x, y, xout, yout, cmd
+int	nvertices, cier, sier, pier, wcs, key, ip, colonkey
+int	prev_num, req_num, ptid, ltid, delim, newlist, newimage
+int	newcenterbuf, newcenter, newskybuf, newsky, newmagbuf, newmag
+int	req_size, old_size, buf_size, memstat
+
+real	apstatr()
+int	ap_ymkpoly(), ap_yfit(), clgcur(), apfitsky(), aprefitsky()
+int	apstati(), ctoi(), ap_ynextobj(), ap_ycenter(), ap_yrecenter()
+int	apgqverify(), apgtverify(), ap_yradsetup(), apnew(), ap_avsky()
+int	ap_memstat(), sizeof()
+bool	fp_equalr()
+data	delim /';'/
+
+define	endswitch_  99
+
+begin
+	# Allocate temporary space.
+	call smark (sp)
+	call salloc (cmd, SZ_LINE, TY_CHAR)
+	call salloc (x, MAX_NVERTICES + 1, TY_REAL)
+	call salloc (y, MAX_NVERTICES + 1, TY_REAL)
+	call salloc (xout, MAX_NVERTICES + 1, TY_REAL)
+	call salloc (yout, MAX_NVERTICES + 1, TY_REAL)
+
+	# Initialize the cursor read.
+	key = ' '
+	Memc[cmd] = EOS
+
+	# Initialize the fit.
+	newimage = NO
+	newcenterbuf = YES; newcenter = YES
+	newskybuf = YES; newsky = YES
+	newmagbuf = YES; newmag = YES
+	cier = AP_OK; sier = AP_OK; pier = AP_OK
+
+	# Initialize the sequencing.
+	newlist = NO
+	ptid = 0
+	ltid = 0
+
+	# Loop over the polygon file.
+	nvertices = 0
+	while (clgcur ("icommands", wx, wy, wcs, key, Memc[cmd], SZ_LINE) !=
+	    EOF) {
+
+	    # Store the current coordinates.
+	    call ap_vtol (im, wx, wy, wx, wy, 1)
+	    call apsetr (py, CWX, wx)
+	    call apsetr (py, CWY, wy)
+
+	    # Has the polygon moved ?
+	    if (apnew (py, wx, wy, apstatr (py, PYCX), apstatr (py, PYCY),
+	        newlist) == YES) {
+		newcenterbuf = YES; newcenter = YES
+		newskybuf = YES; newsky = YES
+		newmagbuf = YES; newmag = YES
+	    }
+
+	    # Loop over the colon commands.
+	    switch (key) {
+
+	    # Quit.
+	    case 'q':
+		if (interactive == YES) {
+		    if (apgqverify ("polyphot", py, key) == YES) {
+			call sfree (sp)
+		        return (apgtverify (key))
+		    }
+		} else {
+		    call sfree (sp)
+		    return (NO)
+		}
+
+	    # Print the help page.
+	    case '?':
+		if ((id != NULL) && (id == gd))
+		    call gpagefile (id, HELPFILE, "")
+		else if (interactive == YES)
+		    call pagefile (HELPFILE, "[space=morehelp,q=quit,?=help]")
+
+	    # Plot a centered stellar radial profile.
+	    case 'd':
+		if (interactive == YES)
+		    call ap_qrad (py, im, wx, wy, gd)
+
+	    # Setup the parameters using a radial profile plot
+	    case 'i':
+		if (interactive == YES) {
+		    nvertices = ap_yradsetup (py, im, id, gd, out, stid,
+		        Memr[x], Memr[y], MAX_NVERTICES)
+		    newlist = NO
+		    newcenterbuf = YES; newcenter = YES
+		    newskybuf = YES; newsky = YES
+		    newmagbuf = YES; newmag = YES
+		}
+
+	    # Verify the critical parameters.
+	    case 'v':
+		call ap_yconfirm (py, out, stid)
+		newcenterbuf = YES; newcenter = YES
+		newskybuf = YES; newsky = YES
+		newmagbuf = YES; newmag = YES
+
+	    # Define a polygon interactively.
+	    case 'g':
+		if (interactive == YES) {
+		    if (id == gd)
+		        nvertices = ap_ymkpoly (py, im, id, Memr[x], Memr[y],
+		            MAX_NVERTICES, NO)
+		    else
+		        nvertices = ap_ymkpoly (py, im, id, Memr[x], Memr[y],
+		            MAX_NVERTICES, YES)
+		    if (id != NULL) {
+			if (id == gd)
+			    call gflush (id)
+			else
+			    call gframe (id)
+		    }
+		    newlist = NO
+		    newcenterbuf = YES; newcenter = YES
+		    newskybuf = YES; newsky = YES
+		    newmagbuf = YES; newmag = YES
+		}
+
+	    # Print error messages.
+	    case 'e':
+		if (interactive == YES)
+		    call ap_pyerrors (py, cier, sier, pier)
+
+	    # Rewind the polygon and coordinate lists.
+	    case 'r':
+		if (pl != NULL) {
+		    call seek (pl, BOF)
+		    if (cl != NULL)
+		        call seek (cl, BOF)
+		    ptid = 0
+		    ltid = 0
+		} else if (interactive == YES)
+		    call printf ("No polygon list\n")
+
+	    # Show/set polyphot parameters.
+	    case ':':
+		for (ip = 1; IS_WHITE(Memc[cmd+ip-1]); ip = ip + 1)
+		    ;
+
+		colonkey = Memc[cmd+ip-1]
+		switch (colonkey) {
+		case 'm', 'n':
+
+		    # Show/set polyphot parameters
+		    if (Memc[cmd+ip] != EOS && Memc[cmd+ip] != ' ') {
+		        call ap_ycolon (py, im, pl, cl, out, stid, ptid, ltid,
+			    Memc[cmd], newimage, newcenterbuf, newcenter,
+			    newskybuf, newsky, newmagbuf, newmag)
+			goto endswitch_
+		    }
+
+	    	    # Measure the next object in the list.
+		    if (pl != NULL) {
+                        if (interactive == YES)
+                            call printf ("No polygon list\n")
+                        goto endswitch_
+		    }
+
+		    # Get the next polygon.
+		    ip = ip + 1
+		    prev_num = ltid
+		    if (ctoi (Memc[cmd], ip, req_num) <= 0)
+		        req_num = ltid + 1
+		    nvertices = ap_ynextobj (py, im, id, pl, cl, delim, Memr[x],
+			Memr[y], MAX_NVERTICES, prev_num, req_num, ltid, ptid)
+		    if (nvertices == EOF) {
+			if (interactive == YES)
+			    call printf (
+				"End of polygon list, use r key to rewind\n")
+			goto endswitch_
+		    }
+
+		    # Move to the next object.
+		    newlist = YES
+		    if (colonkey == 'm') {
+			newcenterbuf = YES; newcenter = YES
+		        newskybuf = YES; newsky = YES
+			newmagbuf = YES; newmag = YES
+			goto endswitch_
+		    }
+
+		    # Fit the center, sky and measure polygon.
+		    cier = ap_ycenter (py, im, apstatr (py, PYCX), apstatr (py,
+		        PYCY), Memr[x], Memr[y], nvertices + 1)
+		    sier = apfitsky (py, im, apstatr (py, PYCX), apstatr (py,
+		        PYCY), NULL, gd)
+		    pier = ap_yfit (py, im, Memr[x], Memr[y], nvertices + 1,
+		        apstatr (py, SKY_MODE), apstatr (py, SKY_SIGMA),
+			apstati (py, NSKY))
+		    if (interactive == YES)
+		        call ap_qyprint (py, cier, sier, pier)
+
+		    # Draw the polygon.
+		    if (id != NULL) {
+		        call appymark (py, id, Memr[x], Memr[y], nvertices + 1,
+		            apstati (py, MKCENTER), apstati (py, MKSKY),
+			    apstati (py, MKPOLYGON))
+			if (id == gd)
+			    call gflush (id)
+			else
+			    call gframe (id)
+		    }
+
+		    # Write the results to output.
+		    if (stid == 1)
+		        call ap_param (py, out, "polyphot")
+
+            	    switch (apstati(py,WCSOUT)) {
+            	    case WCS_WORLD, WCS_PHYSICAL:
+                	call ap_ltoo (py, Memr[x], Memr[y], Memr[xout],
+			    Memr[yout], nvertices + 1)
+            	    case WCS_TV:
+                	call ap_ltov (im, Memr[x], Memr[y], Memr[xout],
+			    Memr[yout], nvertices + 1)
+            	    default:
+			call amovr (Memr[x], Memr[xout], nvertices + 1)
+			call amovr (Memr[y], Memr[yout], nvertices + 1)
+            	    }
+		    if (newlist == YES)
+		        call ap_yprint (py, out, Memr[xout], Memr[yout],
+			    nvertices, stid, ltid, ptid, cier, sier, pier)
+		    else
+			call ap_yprint (py, out, Memr[xout], Memr[yout],
+			    nvertices, stid, 0, ptid, cier, sier, pier)
+
+		     # Set up for the next object.
+		     stid = stid + 1
+		     newcenterbuf = NO; newcenter = NO
+		     newskybuf = NO; newsky = NO
+		     newmagbuf = NO; newmag = NO
+
+		# Show/set polyphot parameters.
+		default:
+		    call ap_ycolon (py, im, pl, cl, out, stid, ptid, ltid,
+		        Memc[cmd], newimage, newcenterbuf, newcenter,
+			newskybuf, newsky, newmagbuf, newmag)
+		}
+
+		# Reestablish the image display viewport and window.
+		if (newimage == YES) {
+		    if ((id != NULL) && (id != gd))
+		        call ap_gswv (id, Memc[cmd], im, 4)
+                    req_size = MEMFUDGE * IM_LEN(im,1) * IM_LEN(im,2) *
+                        sizeof (IM_PIXTYPE(im))
+                    memstat = ap_memstat (cache, req_size, old_size)
+                    if (memstat == YES)
+                        call ap_pcache (im, INDEFI, buf_size)
+		}
+		newimage = NO
+
+	    # Get measure next object in the list.
+	    case 'm', 'n':
+		if (pl == NULL) {
+		    if (interactive == YES)
+		        call printf ("No polygon list\n")
+		    goto endswitch_
+		}
+
+		# Get the next polygon.
+		prev_num = ltid
+		req_num = ltid + 1
+		nvertices = ap_ynextobj (py, im, id, pl, cl, delim, Memr[x],
+		    Memr[y], MAX_NVERTICES, prev_num, req_num, ltid, ptid)
+		if (nvertices == EOF) {
+		    if (interactive == YES)
+			call printf (
+			    "End of polygon list, use r key to rewind\n")
+		    goto endswitch_
+		}
+
+		# Move to next object.
+		newlist = YES
+		if (key == 'm') {
+		    newcenterbuf = YES; newcenter = YES
+		    newskybuf = YES; newsky = YES
+		    newmagbuf = YES; newmag = YES
+		    goto endswitch_
+		}
+
+		# Measure next object.
+		cier = ap_ycenter (py, im, apstatr (py, PYCX), apstatr (py,
+		    PYCY), Memr[x], Memr[y], nvertices + 1)
+		sier = apfitsky (py, im, apstatr (py, PYCX), apstatr (py,
+		    PYCY), NULL, gd)
+		pier = ap_yfit (py, im, Memr[x], Memr[y], nvertices + 1,
+		    apstatr (py, SKY_MODE), apstatr (py, SKY_SIGMA),
+		    apstati (py, NSKY))
+	        if (interactive == YES)
+	            call ap_qyprint (py, cier, sier, pier)
+
+		# Draw the polygon.
+		if (id != NULL) {
+		    call appymark (py, id, Memr[x], Memr[y], nvertices + 1,
+		        apstati (py, MKCENTER), apstati (py, MKSKY),
+			apstati (py, MKPOLYGON))
+		    if (id == gd)
+			call gflush (id)
+		    else
+			call gframe (id)
+		}
+
+		# Write the results to output.
+		if (stid == 1)
+		    call ap_param (py, out, "polyphot")
+                switch (apstati(py,WCSOUT)) {
+                case WCS_WORLD, WCS_PHYSICAL:
+                    call ap_ltoo (py, Memr[x], Memr[y], Memr[xout], Memr[yout],
+			nvertices + 1)
+                case WCS_TV:
+                    call ap_ltov (im, Memr[x], Memr[y], Memr[xout], Memr[yout],
+			nvertices + 1)
+                default:
+		    call amovr (Memr[x], Memr[xout], nvertices + 1)
+		    call amovr (Memr[y], Memr[yout], nvertices + 1)
+                }
+		if (newlist == YES)
+		    call ap_yprint (py, out, Memr[xout], Memr[yout], nvertices,
+		        stid, ltid, ptid, cier, sier, pier)
+		else
+		    call ap_yprint (py, out, Memr[xout], Memr[yout], nvertices,
+		        stid, 0, ptid, cier, sier, pier)
+
+		# Set up for the next object.
+		stid = stid + 1
+		newcenterbuf = NO; newcenter = NO
+		newskybuf = NO; newsky = NO
+		newmagbuf = NO; newmag = NO
+
+	    # Process the remainder of the list.
+	    case 'l':
+		if (pl != NULL) {
+		    call ap_ybphot (py, im, cl, pl, out, stid, ltid, ptid, id,
+		        YES)
+		    if (id != NULL) {
+			if (id == gd)
+			    call gflush (id)
+			else
+			    call gframe (id)
+		    }
+		} else if (interactive == YES)
+		    call printf ("No polygon list\n")
+
+	    # Save current parameters in the pset file.
+	    case 'w':
+		call ap_pypars (py)
+
+	    # Center the current polygon around the cursor poition.
+	    case 'c':
+		if (newcenterbuf == YES)
+		    cier = ap_ycenter (py, im, wx, wy, Memr[x], Memr[y],
+		        nvertices + 1)
+		else if (newcenter == YES)
+		    cier = ap_yrecenter (py, im, Memr[x], Memr[y],
+		        nvertices + 1, cier)
+		if (interactive == YES)
+		    call ap_qcenter (py, cier)
+		if (id != NULL) {
+		    call apmark (py, id, apstati (py, MKCENTER), NO, NO)
+		    if (id == gd)
+		        call gflush (id)
+		    else
+			call gframe (id)
+		}
+		newcenterbuf = NO; newcenter = NO
+
+	    # Fit the sky around the cursor position.
+	    case 't':
+		if (newskybuf == YES || ! fp_equalr (wx,
+		    apstatr (py, SXCUR)) || ! fp_equalr (wy, apstatr (py,
+		    SYCUR)))
+		    sier = apfitsky (py, im, wx, wy, NULL, gd)
+	        else if (newsky == YES)
+		    sier = aprefitsky (py, im, gd)
+		if (interactive == YES)
+		    call ap_qspsky (py, sier)
+		if (id != NULL) {
+		    call apmark (py, id, NO, apstati (py, MKSKY), NO)
+		    if (id == gd)
+		        call gflush (id)
+		    else
+			call gframe (id)
+		}
+		newskybuf = NO; newsky = NO
+
+ 	    # Compute the average of several sky measurements around
+            # different cursor postions.
+            case 'a':
+                sier = ap_avsky (py, im, stid, NULL, id, gd, interactive)
+                if (interactive == YES)
+                    call ap_qaspsky (py, sier)
+                newskybuf = NO; newsky = NO
+
+	     # Fit sky in an annulus around the current polygon.
+	     case 's':
+	        if (newskybuf == YES || ! fp_equalr (apstatr (py, PYCX),
+		    apstatr (py, SXCUR)) || ! fp_equalr (apstatr (py, PYCY),
+		    apstatr (py, SYCUR)))
+		    sier = apfitsky (py, im, apstatr (py, PYCX), apstatr (py,
+		        PYCY), NULL, gd)
+		else if (newsky == YES)
+		    sier = aprefitsky (py, im, gd)
+		if (interactive == YES)
+		    call ap_qspsky (py, sier)
+		if (id != NULL) {
+		    call apmark (py, id, NO, apstati (py, MKSKY), NO)
+		    if (id == gd)
+		        call gflush (id)
+		    else
+			call gframe (id)
+		}
+		newskybuf = NO; newsky = NO
+
+	    # Compute the magnitudes of current polygon using the current sky.
+	    case 'p', 'o':
+		if (newcenterbuf == YES)
+		    cier = ap_ycenter (py, im, wx, wy, Memr[x], Memr[y],
+		        nvertices + 1)
+		else if (newcenter == YES)
+		    cier = ap_yrecenter (py, im, Memr[x], Memr[y],
+		        nvertices + 1, cier)
+		pier = ap_yfit (py, im, Memr[x], Memr[y], nvertices + 1,
+		    apstatr (py, SKY_MODE), apstatr (py, SKY_SIGMA),
+		    apstati (py, NSKY))
+		if (interactive == YES)
+		    call ap_qyprint (py, cier, sier, pier)
+		if (id != NULL) {
+		    call appymark (py, id, Memr[x], Memr[y], nvertices + 1,
+		        NO, NO, apstati (py, MKPOLYGON))
+		    if (id == gd)
+		        call gflush (id)
+		    else
+			call gframe (id)
+		}
+		newcenterbuf = NO; newcenter = NO
+		newmagbuf = NO; newmag = NO
+
+		# Write the results.
+		if (key == 'o') {
+		    if (stid == 1)
+		        call ap_param (py, out, "polyphot")
+            	    switch (apstati(py,WCSOUT)) {
+            	    case WCS_WORLD, WCS_PHYSICAL:
+                	call ap_ltoo (py, Memr[x], Memr[y], Memr[xout],
+			    Memr[yout], nvertices + 1)
+            	    case WCS_TV:
+                	call ap_ltov (im, Memr[x], Memr[y], Memr[xout],
+			    Memr[yout], nvertices + 1)
+            	    default:
+		        call amovr (Memr[x], Memr[xout], nvertices + 1)
+		        call amovr (Memr[y], Memr[yout], nvertices + 1)
+            	    }
+		    if (newlist == YES)
+		        call ap_yprint (py, out, Memr[xout], Memr[yout],
+			    nvertices, stid, ltid, ptid, cier, sier, pier)
+		    else
+		        call ap_yprint (py, out, Memr[xout], Memr[yout],
+			    nvertices, stid, 0, ptid, cier, sier, pier)
+		    stid = stid + 1
+		}
+
+	    # Center, compute the sky and the magnitudes and save the results.
+	    case 'h', 'j', 'f', ' ':
+
+		# Compute the centers.
+		if (key == 'f' || key == ' ') {
+		    if (newcenterbuf == YES)
+		        cier = ap_ycenter (py, im, wx, wy, Memr[x], Memr[y],
+		            nvertices + 1)
+		    else if (newcenter == YES)
+		        cier = ap_yrecenter (py, im, Memr[x], Memr[y],
+			    nvertices + 1, cier)
+		} else {
+		    if (newcenterbuf == YES)
+		        cier = ap_ycenter (py, im, apstatr (py, PYCX),
+			    apstatr (py, PYCY), Memr[x], Memr[y], nvertices + 1)
+		    else if (newcenter == YES)
+		        cier = ap_yrecenter (py, im, Memr[x], Memr[y],
+			    nvertices + 1, cier)
+		}
+
+		# Compute the sky values and the magnitudes.
+	        if (newskybuf == YES || ! fp_equalr (apstatr (py,
+		    PYCX), apstatr (py, SXCUR)) || ! fp_equalr (apstatr (py,
+		    PYCY), apstatr (py, SYCUR))) sier = apfitsky (py, im,
+		    apstatr (py, PYCX), apstatr (py, PYCY), NULL, gd)
+		else if (newsky == YES)
+		    sier = aprefitsky (py, im, gd)
+		pier = ap_yfit (py, im, Memr[x], Memr[y], nvertices + 1,
+		    apstatr (py, SKY_MODE), apstatr (py, SKY_SIGMA),
+		    apstati (py, NSKY))
+
+		if (interactive == YES)
+		    call ap_qyprint (py, cier, sier, pier)
+		if (id != NULL) {
+		    call appymark (py, id, Memr[x], Memr[y], nvertices + 1,
+		        apstati (py, MKCENTER), apstati (py, MKSKY),
+			apstati (py, MKPOLYGON))
+		    if (id == gd)
+		        call gflush (id)
+		    else
+			call gframe (id)
+		}
+
+		newcenterbuf = NO; newcenter = NO
+		newskybuf = NO; newsky = NO
+		newmagbuf = NO; newmag = NO
+
+		# Write the results to an output file.
+		if (key == ' ' || key == 'j') {
+		    if (stid == 1)
+		        call ap_param (py, out, "polyphot")
+            	    switch (apstati(py,WCSOUT)) {
+            	    case WCS_WORLD, WCS_PHYSICAL:
+                	call ap_ltoo (py, Memr[x], Memr[y], Memr[xout],
+			    Memr[yout], nvertices + 1)
+            	    case WCS_TV:
+                	call ap_ltov (im, Memr[x], Memr[y], Memr[xout],
+			    Memr[yout], nvertices + 1)
+            	    default:
+		        call amovr (Memr[x], Memr[xout], nvertices + 1)
+		        call amovr (Memr[y], Memr[yout], nvertices + 1)
+            	    }
+		    if (newlist == YES)
+		        call ap_yprint (py, out, Memr[xout], Memr[yout],
+			    nvertices, stid, ltid, ptid, cier, sier, pier)
+		    else
+		        call ap_yprint (py, out, Memr[xout], Memr[yout],
+			    nvertices, stid, 0, ptid, cier, sier, pier)
+		    stid = stid + 1
+		}
+
+	    default:
+		call printf ("Unknown or ambigous keystroke command\n")
+	    }
+
+endswitch_
+	    # Reset the keystroke and command defaults.
+	    key = ' '
+	    Memc[cmd] = EOS
+	    call apsetr (py, WX, apstatr (py, CWX))
+	    call apsetr (py, WY, apstatr (py, CWY))
+	}
+
+end
diff --git a/noao/digiphot/apphot/polyphot/apyprint.x b/noao/digiphot/apphot/polyphot/apyprint.x
new file mode 100644
index 00000000..dda24c3f
--- /dev/null
+++ b/noao/digiphot/apphot/polyphot/apyprint.x
@@ -0,0 +1,94 @@
+include "../lib/apphot.h"
+include "../lib/center.h"
+include "../lib/fitsky.h"
+include "../lib/polyphot.h"
+
+# AP_YPRINT -- Write the results of the polyphot task to the output file.
+
+procedure ap_yprint (py, fd, xver, yver, nver, id, lid, pid, cier, sier, pier)
+
+pointer	py		# pointer to apphot structure
+int	fd		# output file descriptor
+real	xver[ARB]	# coords of x vertices
+real	yver[ARB]	# coords of y vertices
+int	nver		# number of vertices
+int	id		# id number of str
+int	lid		# list id number of star
+int	pid		# polygon number
+int	cier		# centering error
+int	sier		# sky fitting error
+int	pier		# photometric error
+
+real	apstatr()
+
+begin
+	if (fd == NULL)
+	    return
+
+	# Write object id parameters.
+	call ap_wid (py, fd, apstatr (py, OXINIT), apstatr (py, OYINIT), id,
+	    lid, '\\')
+
+	# Write the centering parameters
+	call ap_wcres (py, fd, cier, '\\')
+
+	# Write the fitsky parameters.
+	call ap_wsres (py, fd, sier, '\\')
+
+	# Write the polyphot parameters
+	call ap_wlres (py, fd, xver, yver, nver, pid, pier)
+end
+
+
+# AP_QYPRINT -- Print a quick summary of the polyphot results on the standard
+# output.
+
+procedure ap_qyprint (py, cier, sier, pier)
+
+pointer	py	# pointer to apphot structure
+int	cier	# centering error
+int	sier	# sky fitting error
+int	pier	# photometry error
+
+pointer	sp, imname
+real	apstatr()
+
+begin
+	# Allocate space.
+	call smark (sp)
+	call salloc (imname, SZ_FNAME, TY_CHAR)
+
+	# Print polyphot magnitudes.
+	#call apstats (py, IMNAME, Memc[imname], SZ_FNAME)
+	call apstats (py, IMROOT, Memc[imname], SZ_FNAME)
+	call printf ("%s  %8.2f %8.2f  %8g  ")
+	    call pargstr (Memc[imname])
+	    call pargr (apstatr (py, OPYCX))
+	    call pargr (apstatr (py, OPYCY))
+	    call pargr (apstatr (py, SKY_MODE))
+	call printf ("%7.3f  %s\n")
+	    call pargr (apstatr (py, PYMAG))
+	if (cier != AP_OK || sier != AP_OK || pier != AP_OK)
+	    call pargstr ("err")
+	else
+	    call pargstr ("ok")
+
+	call sfree (sp)
+end
+
+
+# AP_YHDR -- Write the polyphot header banner to the output file.
+
+procedure ap_yhdr (ap, fd)
+
+pointer	ap		# apphot structure
+int 	fd		# output file descriptor
+
+begin
+	if (fd == NULL)
+	    return
+	call ap_idhdr (ap, fd)
+	call ap_chdr (ap, fd)
+	call ap_shdr (ap, fd)
+	call ap_plhdr (ap, fd)
+end
diff --git a/noao/digiphot/apphot/polyphot/apyradsetup.x b/noao/digiphot/apphot/polyphot/apyradsetup.x
new file mode 100644
index 00000000..a966110b
--- /dev/null
+++ b/noao/digiphot/apphot/polyphot/apyradsetup.x
@@ -0,0 +1,135 @@
+include "../lib/fitsky.h"
+include "../lib/polyphot.h"
+
+define	HELPFILE	"apphot$polyphot/ipolyphot.key"
+
+# AP_YRADSETUP - Set up polyphot interactively using a radial profile
+# plot of a bright star.
+
+int procedure ap_yradsetup (ap, im, id, gd, out, stid, x, y, max_nvertices)
+
+pointer	ap			# pointer to apphot structure
+pointer	im			# pointer to the IRAF image
+pointer	id			# pointer to the image display
+pointer	gd			# pointer to graphics stream
+int	out			# output file descriptor
+int	stid			# output file sequence number
+real	x[ARB]			# array of x vertices
+real	y[ARB]			# array of y vertices
+int	max_nvertices		# maximum number of vertices
+
+int	nvertices, cier, sier, pier, key, wcs
+pointer	sp, str, cmd
+real	rmin, rmax, imin, imax, u1, u2, v1, v2, x1, x2, y1, y2
+real	xcenter, ycenter, xc, yc, rval
+
+int	ap_ycenter(), clgcur(), ap_showplot()
+int	apfitsky(),  ap_yfit(), apstati(), ap_ymkpoly()
+real	apstatr(), ap_cfwhmpsf(), ap_ccapert(), ap_cannulus(), ap_csigma()
+real	ap_cdannulus(), ap_cdatamin(), ap_cdatamax()
+real	ap_crgrow(), ap_crclean(), ap_crclip()
+
+begin
+	# Mark the polygon interactively.
+	if (id == gd)
+	    nvertices = ap_ymkpoly (ap, im, id, x, y, max_nvertices, NO)
+	else
+	    nvertices = ap_ymkpoly (ap, im, id, x, y, max_nvertices, YES)
+	if (id != NULL) {
+	    if (gd == id)
+		call gflush (id)
+	    else
+		call gframe (id)
+	}
+	if (nvertices <= 0)
+	    return (nvertices)
+
+	# Store the viewport and window coordinates.
+	call ggview (gd, u1, u2, v1, v2)
+	call ggwind (gd, x1, x2, y1, y2)
+
+	# Check for open display device and graphics stream.
+	if (gd == NULL)
+	    return (0)
+	call greactivate (gd, 0)
+
+	# Show the plot.
+	if (ap_showplot (ap, im, apstatr (ap, PYCX), apstatr (ap, PYCY), gd,
+	    xcenter, ycenter, rmin, rmax, imin, imax) == ERR) {
+	    call gdeactivate (gd, 0)
+	    return (nvertices)
+	}
+
+	# Allocate memory.
+	call smark (sp)
+	call salloc (str, SZ_LINE, TY_CHAR)
+	call salloc (cmd, SZ_LINE, TY_CHAR)
+
+        call printf (
+	"Waiting for setup menu command (?=help, v=default setup, q=quit):\n")
+	while (clgcur ("gcommands", xc, yc, wcs, key, Memc[cmd],
+	    SZ_LINE) != EOF) {
+
+	switch (key) {
+
+	    case 'q':
+	        break
+	    case '?':
+		call gpagefile (gd, HELPFILE, "")
+	    case 'f':
+		rval = ap_cfwhmpsf (ap, gd, out, stid, rmin, rmax, imin, imax)
+	    case 'h':
+		#rval = ap_ccthresh (ap, gd, out, stid, rmin, rmax, imin, imax)
+	    case 'c':
+		rval = ap_ccapert (ap, gd, out, stid, rmin, rmax, imin, imax)
+	    case 's':
+	        rval = ap_csigma (ap, gd, out, stid, rmin, rmax, imin, imax)
+	    case 'n':
+		rval = ap_crclean (ap, gd, out, stid, rmin, rmax, imin, imax)
+	    case 'p':
+		rval = ap_crclip (ap, gd, out, stid, rmin, rmax, imin, imax)
+	    case 'l':
+	        rval = ap_cdatamin (ap, gd, out, stid, rmin, rmax, imin, imax)
+	    case 'u':
+	        rval = ap_cdatamax (ap, gd, out, stid, rmin, rmax, imin, imax)
+	    case 'a':
+		rval = ap_cannulus (ap, gd, out, stid, rmin, rmax, imin, imax)
+	    case 'd':
+		rval = ap_cdannulus (ap, gd, out, stid, apstatr (ap, ANNULUS),
+		    rmin, rmax, imin, imax)
+	    case 'g':
+		rval = ap_crgrow (ap, gd, out, stid, rmin, rmax, imin, imax)
+	    case 'v':
+		rval = ap_cfwhmpsf (ap, gd, out, stid, rmin, rmax, imin, imax)
+		rval = ap_ccapert (ap, gd, out, stid, rmin, rmax, imin, imax)
+	        rval = ap_csigma (ap, gd, out, stid, rmin, rmax, imin, imax)
+		rval = ap_cannulus (ap, gd, out, stid, rmin, rmax, imin, imax)
+		rval = ap_cdannulus (ap, gd, out, stid, apstatr (ap, ANNULUS),
+		    rmin, rmax, imin, imax)
+	    default:
+		call printf ("Unknown or ambiguous keystroke command\007\n")
+	    }
+            call printf (
+	"Waiting for setup menu command (?=help, v=default setup, q=quit):\n")
+	}
+	call printf (
+	    "Interactive setup is complete. Type w to save parameters.\n")
+
+	# Restore the viewport and window coordinates.
+	call gsview (gd, u1, u2, v1, v2)
+	call gswind (gd, x1, x2, y1, y2)
+
+	# Clean up memory space.
+	call gdeactivate (gd, 0)
+	call sfree (sp)
+
+	# Print the answer.
+	cier = ap_ycenter (ap, im, xcenter, ycenter, x, y, nvertices + 1)
+	sier = apfitsky (ap, im, apstatr (ap, PYCX), apstatr (ap, PYCY),
+	    NULL, gd)
+	pier = ap_yfit (ap, im, x, y, nvertices + 1, apstatr (ap, SKY_MODE),
+	    apstatr (ap, SKY_SIGMA), apstati (ap, NSKY))
+	call ap_qyprint (ap, cier, sier, pier)
+
+	return (nvertices)
+end
diff --git a/noao/digiphot/apphot/polyphot/apyshift.x b/noao/digiphot/apphot/polyphot/apyshift.x
new file mode 100644
index 00000000..4fd56cbe
--- /dev/null
+++ b/noao/digiphot/apphot/polyphot/apyshift.x
@@ -0,0 +1,41 @@
+include "../lib/apphot.h"
+include "../lib/polyphot.h"
+
+# AP_YSHIFT -- Shift a polygon to a new center position.
+
+procedure ap_yshift (py, im, x, y, nver, newx, newy)
+
+pointer	py		# pointer to the polyphot structure
+pointer	im		# the input image descriptor
+real	x[ARB]		# x coordinates of the vertices
+real	y[ARB]		# y coordinates of the vertices
+int	nver		# number of vertices
+real	newx, newy	# new x and y coordinates of center
+
+real	xshift, yshift
+real	apstatr()
+int	apstati()
+
+begin
+	call apsetr (py, PYX, apstatr (py, PYCX))
+	call apsetr (py, PYY, apstatr (py, PYCY))
+
+	xshift = newx - apstatr (py, PYCX)
+	yshift = newy - apstatr (py, PYCY)
+	call aaddkr (x, xshift, x, nver)
+	call aaddkr (y, yshift, y, nver)
+	call apsetr (py, PYCX, newx)
+	call apsetr (py, PYCY, newy)
+
+        switch (apstati(py,WCSOUT)) {
+        case WCS_WORLD, WCS_PHYSICAL:
+            call ap_ltoo (py, newx, newy, xshift, yshift, 1)
+        case WCS_TV:
+            call ap_ltov (im, newx, newy, xshift, yshift, 1)
+        default:
+	    xshift = newx
+	    yshift = newy
+        }
+        call apsetr (py, OPYCX, xshift)
+        call apsetr (py, OPYCY, yshift)
+end
diff --git a/noao/digiphot/apphot/polyphot/apywrite.x b/noao/digiphot/apphot/polyphot/apywrite.x
new file mode 100644
index 00000000..b246aac3
--- /dev/null
+++ b/noao/digiphot/apphot/polyphot/apywrite.x
@@ -0,0 +1,92 @@
+include "../lib/apphot.h"
+include "../lib/polyphot.h"
+
+# AP_YWRITE -- Procedure to write a polygon to a file.
+
+procedure ap_ywrite (py, im, cl, pl, x, y, nvertices, cid, pid, firstpoly,
+	newpoly)
+
+pointer	py		# pointer to the apphot structure
+pointer	im		# the input image descriptor
+int	cl		# pointer to the coordinate list file
+int	pl		# pointer to the polygon list file
+real	x[ARB]		# x coordinates of the vertices
+real	y[ARB]		# y coordinates of the vertices
+int	nvertices	# number of vertices
+int	cid		# coordinate list index
+int	pid		# polygon list index
+int	firstpoly	# first polygon measured
+int	newpoly		# new polygon
+
+real	xtemp, ytemp
+int	i
+real	apstatr()
+int	apstati()
+
+begin
+	# Make sure the output files are at EOF.
+	if (pl == NULL)
+	    return
+	call seek (pl, EOF)
+	if (cl != NULL)
+	    call seek (cl, EOF)
+
+	if (newpoly == YES) {
+
+	    # Terminate the coord list that belongs with the first polygon.
+	    if (firstpoly == NO && cl != NULL)
+		call fprintf (cl, ";\n")
+
+	    # Write out the coordinates.
+	    do i = 1, nvertices {
+                switch (apstati(py, WCSOUT)) {
+                case WCS_WORLD, WCS_PHYSICAL:
+                    call ap_ltoo (py, x[i], y[i], xtemp, ytemp, 1)
+                case WCS_TV:
+                    call ap_ltov (im, x[i], y[i], xtemp, ytemp, 1)
+                default:
+		    xtemp = x[i]
+		    ytemp = y[i]
+                }
+		call fprintf (pl, "%g  %g\n")
+		    call pargr (xtemp)
+		    call pargr (ytemp)
+	    }
+	    if (nvertices > 0)
+	        call fprintf (pl, ";\n")
+
+	    pid = pid + 1
+
+	    # Reset polygon parameters.
+	    newpoly = NO
+	    if (firstpoly == YES)
+		firstpoly = NO
+	}
+
+	# Write out the central coordinates of the polygon.
+	if (firstpoly == NO && cl != NULL) {
+
+            switch (apstati(py, WCSOUT)) {
+            case WCS_WORLD, WCS_PHYSICAL:
+                call ap_ltoo (py, apstatr(py,CWX), apstatr(py,CWY), xtemp,
+		    ytemp, 1)
+            case WCS_TV:
+                call ap_ltov (im, apstatr(py,CWX), apstatr(py,CWY), xtemp,
+		    ytemp, 1)
+            default:
+		xtemp = apstatr (py, CWX)
+		ytemp = apstatr (py, CWY)
+            }
+	    call fprintf (cl, "%g  %g\n")
+		call pargr (xtemp)
+		call pargr (ytemp)
+
+	    cid = cid + 1
+	}
+
+	# Flush the output files.
+	if (pl != NULL)
+	    call flush (pl)
+	if (cl != NULL)
+	    call flush (cl)
+end
diff --git a/noao/digiphot/apphot/polyphot/ipolyphot.key b/noao/digiphot/apphot/polyphot/ipolyphot.key
new file mode 100644
index 00000000..f8ef878c
--- /dev/null
+++ b/noao/digiphot/apphot/polyphot/ipolyphot.key
@@ -0,0 +1,16 @@
+                    Interactive Photometry Setup Menu
+
+	v	Mark and verify the critical parameters (f,c,s,a,d)
+
+	f	Mark and verify the psf full-width half-maximum
+	s	Mark and verify the standard deviation of the background
+	l	Mark and verify the minimum good data value
+	u	Mark and verify the maximum good data value
+
+	c	Mark and verify the centering box width
+	n	Mark and verify the cleaning radius
+	p	Mark and verify the clipping radius
+
+	a	Mark and verify the inner radius of the sky annulus
+	d	Mark and verify the width of the sky annulus
+	g	Mark and verify the region growing radius
diff --git a/noao/digiphot/apphot/polyphot/mkpkg b/noao/digiphot/apphot/polyphot/mkpkg
new file mode 100644
index 00000000..b98b6803
--- /dev/null
+++ b/noao/digiphot/apphot/polyphot/mkpkg
@@ -0,0 +1,60 @@
+# POLYPHOT and POLYMARK routines
+
+$checkout libpkg.a ".."
+$update libpkg.a
+$checkin  libpkg.a ".."
+$exit
+
+libpkg.a:
+	# POLYPHOT routines
+
+	appyerrors.x	../lib/polyphot.h
+	apgypars.x	../lib/display.h	../lib/fitsky.h         \
+			../lib/noise.h          ../lib/polyphot.h	\
+			../lib/center.h
+	apycenter.x	../lib/center.h		../lib/polyphot.h
+	apyconfirm.x	../lib/apphot.h		../lib/noise.h		\
+			../lib/center.h		../lib/fitsky.h
+	apycoords.x	../lib/polyphot.h
+	apyfree.x	../lib/apphotdef.h	../lib/polyphotdef.h
+	apyinit.x	../lib/apphotdef.h	../lib/polyphotdef.h
+	apynextobj.x	<fset.h>		../lib/apphot.h         \
+	                ../lib/polyphot.h
+	apypars.x	
+	apyradsetup.x	../lib/fitsky.h		../lib/polyphot.h
+	apyshift.x	../lib/apphot.h         ../lib/polyphot.h
+	apycolon.x	../lib/polyphot.h	../lib/center.h         \
+			../lib/apphot.h		../lib/fitsky.h         \
+			../lib/noise.h		../lib/display.h	\
+			<gset.h>		<error.h>
+	apyfit.x	../lib/polyphot.h	../lib/noise.h          \
+			../lib/apphot.h		 <imhdr.h>              \
+			<mach.h>
+	apyget.x	<fset.h>		../lib/apphot.h         \
+			../lib/fitsky.h		../lib/polyphot.h
+	polyshow.x	../lib/display.h	../lib/polyphot.h
+	apybphot.x	<fset.h>		../lib/display.h        \
+			../lib/polyphot.h	../lib/fitsky.h         \
+			../lib/apphot.h
+	apyphot.x	<ctype.h>		<gset.h>                \
+			../lib/display.h	../lib/polyphot.h	\
+			../lib/fitsky.h		../lib/apphot.h         \
+			<imhdr.h>
+	apyprint.x	../lib/fitsky.h		../lib/center.h         \
+			../lib/apphot.h		../lib/polyphot.h
+	t_polyphot.x	<gset.h>		<fset.h>		\
+			../lib/apphot.h		../lib/polyphot.h       \
+			<imhdr.h>
+
+	# POLYMARK routines
+
+	t_polymark.x	<gset.h>		<fset.h>		\
+			"../lib/apphot.h"	"../lib/polyphot.h"     \
+			<imhdr.h>
+	apmkpylist.x	<gset.h>		<ctype.h>		\
+			"../lib/apphot.h"	"../lib/polyphot.h"
+	apydraw.x	"../lib/polyphot.h"
+	apymkinit.x	"../lib/apphotdef.h"    "../lib/noise.h"
+	apymkfree.x	"../lib/apphotdef.h"
+	apywrite.x	"../lib/apphot.h"	"../lib/polyphot.h"
+	;
diff --git a/noao/digiphot/apphot/polyphot/polymark.key b/noao/digiphot/apphot/polyphot/polymark.key
new file mode 100644
index 00000000..9e1901a1
--- /dev/null
+++ b/noao/digiphot/apphot/polyphot/polymark.key
@@ -0,0 +1,16 @@
+	Interactive Keystroke Commands
+
+?	Print help
+:	Colon commands 
+d	Plot radial profile of star near cursor
+g	Define the current polygonal aperture
+f	Draw the current polygon on the display
+spbar	Draw the current polygon on the display, output the polygon
+r	Rewind the polygon list
+m	Draw the next polygon in the polygon list on the display
+l	Draw all the remaining polygons in the list on the display
+q	Exit
+
+	Colon commands
+
+:m [n]	Draw the next [nth] polygon in the polygon list on the display
diff --git a/noao/digiphot/apphot/polyphot/polyphot.key b/noao/digiphot/apphot/polyphot/polyphot.key
new file mode 100644
index 00000000..e2c92da2
--- /dev/null
+++ b/noao/digiphot/apphot/polyphot/polyphot.key
@@ -0,0 +1,110 @@
+	Interactive Keystroke Commands
+
+?	Print help
+:	Colon commands
+v	Verify the critical parameters
+w	Store the current parameters
+d	Plot radial profile of current object
+i	Define current polygon, graphically set parameters using current object
+g	Define current polygon
+c	Fit center for current object
+t	Fit sky around cursor
+a       Average sky values fit around several cursor positions
+s	Fit sky around current object
+h	Do photometry for current polygon
+j	Do photometry for current polygon, output results
+p	Do photometry for current object using current sky
+o	Do photometry for current object using current sky, output results
+f	Do photometry for current object
+spbar	Do photometry for current object, output results
+m	Move to next object in coordinate list
+n	Do photometry for next object in coordinate list, output results
+l	Do photometry for remaining objects in coordinate list, output results
+r	Rewind the the coordinate list
+e	Print error messages
+q	Exit task
+
+
+	Colon Commands
+
+:show	[data/center/sky/phot]	List the parameters
+:m [n]	Move to next [nth] object in coordinate list
+:n [n]	Do photometry for next [nth] object in coordinate list, output results
+
+
+	Colon Parameter Editing Commands
+
+# Image and file name parameters
+
+:image		[string]	Image name
+:polygon	[string]	Polygon file
+:coords		[string]	Coordinate file
+:output		[string]	Results file
+
+# Data dependent parameters
+
+:scale		[value]		Image scale (units per pixel)
+:fwhmpsf	[value]		Full-width half-maximum of PSF (scale units)
+:emission	[y/n]		Emission feature (y), absorption (n)
+:sigma		[value]		Standard deviation of sky (counts)
+:datamin	[value]		Minimum good pixel value (counts)
+:datamax	[value]		Maximum good pixel value (counts)
+
+# Noise parameters
+
+:noise		[string]	Noise model (constant|poisson)
+:gain		[string]	Gain image header keyword
+:ccdread	[string]	Readout noise image header keyword
+:epadu		[value]		Gain (electrons per count)
+:epadu		[value]		Readout noise (electrons)
+
+# Observing parameters
+
+:exposure	[string]	Exposure time image header keyword
+:airmass	[string]	Airmass image header keyword
+:filter		[string]	Filter image header keyword
+:obstime	[string]	Time of observation image header keyword
+:itime		[value]		Integration time (time units)
+:xairmass	[value]		Airmass value (number)
+:ifilter	[string]	Filter id string
+:otime		[string]	Time of observation (time units)
+
+# Centering algorithm parameters
+
+:calgorithm	[string]	Centering algorithm
+:cbox		[value]		Width of centering box (scale units)
+:cthreshold	[value]		Centering intensity threshold (sigma)
+:cmaxiter	[value]		Maximum number of iterations
+:maxshift	[value]		Maximum center shift (scale units)
+:minsnratio	[value]		Minimum S/N ratio for centering
+:clean		[y/n]		Clean subraster before centering
+:rclean		[value]		Cleaning radius (scale units)
+:rclip		[value]		Clipping radius (scale units)
+:kclean		[value]		Clean K-sigma rejection limit (sigma)
+
+# Sky fitting algorithm parameters
+
+:salgorithm	[string]	Sky fitting algorithm 
+:skyvalue	[value]		User supplied sky value (counts)
+:annulus	[value]		Inner radius of sky annulus (scale units)
+:dannulus	[value]		Width of sky annulus (scale units)
+:khist		[value]		Sky histogram extent (+/- sigma)
+:binsize	[value]		Resolution of sky histogram (sigma)
+:sloclip	[value]		Low-side clipping factor in percent
+:shiclip	[value]		High-side clipping factor in percent
+:smooth		[y/n]		Lucy smooth the sky histogram
+:smaxiter	[value]		Maximum number of iterations
+:snreject	[value]		Maximum number of rejection cycles
+:sloreject	[value]		Low-side pixel rejection limits (sky sigma)
+:shireject	[value]		High-side pixel rejection limits (sky sigma)
+:rgrow		[value]		Region growing radius (scale units)
+
+# Photometry parameters
+
+:zmag		[value]		Zero point of magnitude scale
+
+# Plotting and marking parameters
+
+:mkcenter	[y/n]		Mark computed centers on the display
+:mksky		[y/n]		Mark the sky annuli on the display
+:mkpolygon	[y/n]		Mark the polygon on the display
diff --git a/noao/digiphot/apphot/polyphot/polyshow.x b/noao/digiphot/apphot/polyphot/polyshow.x
new file mode 100644
index 00000000..9e3da070
--- /dev/null
+++ b/noao/digiphot/apphot/polyphot/polyshow.x
@@ -0,0 +1,65 @@
+include "../lib/display.h"
+include "../lib/polyphot.h"
+
+# AP_YSHOW -- Print the all the polyphot parameters on the standard output.
+
+procedure ap_yshow (ap)
+
+pointer	ap	# pointer to the apphot strucuture
+
+begin
+	call ap_nshow (ap)
+	call printf ("\n")
+	call ap_cpshow (ap)
+	call printf ("\n")
+	call ap_spshow (ap)
+	call printf ("\n")
+	call ap_yyshow (ap)
+end
+
+
+# AP_YPSHOW -- Print the noise and polypars parameters on the standard output.
+
+procedure ap_ypshow (ap)
+
+pointer	ap		# pointer to apphot structure
+
+begin
+	call ap_nshow (ap)
+	call printf ("\n")
+	call ap_yyshow (ap)
+end
+
+
+# AP_YYSHOW --  Print the polypars parameters on the standard output.
+
+procedure ap_yyshow (ap)
+
+pointer	ap		# pointer to apphot structure
+
+pointer	sp, str
+bool	itob()
+int	apstati()
+real	apstatr()
+
+begin
+	call smark (sp)
+	call salloc (str, SZ_LINE, TY_CHAR)
+
+	call printf ("Photometry Parameters\n")
+
+	call apstats (ap, PYNAME, Memc[str], SZ_LINE)
+	call printf ("    %s = %s\n")
+	    call pargstr (KY_PYNAME)
+	    call pargstr (Memc[str])
+
+	call printf ("    %s = %g\n")
+	    call pargstr (KY_PYZMAG)
+	    call pargr (apstatr (ap, PYZMAG))
+
+	call printf ("    %s = %b\n")
+	    call pargstr (KY_MKPOLYGON)
+	    call pargb (itob (apstati (ap, MKPOLYGON)))
+
+	call sfree (sp)
+end
diff --git a/noao/digiphot/apphot/polyphot/t_polymark.x b/noao/digiphot/apphot/polyphot/t_polymark.x
new file mode 100644
index 00000000..4eea5207
--- /dev/null
+++ b/noao/digiphot/apphot/polyphot/t_polymark.x
@@ -0,0 +1,240 @@
+include <gset.h>
+include <fset.h>
+include <imhdr.h>
+include "../lib/apphot.h"
+include "../lib/polyphot.h"
+
+define	MAX_NVERTICES	100
+
+# T_POLYMARK -- Create a polygons list file interactively.
+
+procedure t_polymark()
+
+pointer	image			# pointer to name of image
+pointer	polygons		# pointer to the polygons file
+pointer	coords			# pointer to the coords file
+int	cache			# cache the input image pixels in memory 
+pointer	display			# pointer to display device name
+pointer	graphics		# pointer to the graphics device
+
+pointer	sp, cfname, pfname, im, py, id, gd, str
+int	limlist, lplist, lclist, stat, pl, cl, root, pid, cid, wcs
+int	imlist, plist, clist, newpy, newcoo, memstat, req_size, old_size
+int	buf_size
+
+pointer	gopen(), immap()
+int	imtlen(), clplen(), imtgetim(), clgfil(), strncmp(), strlen()
+int	fnldir(), ap_mkpylist(), imtopenp(), clpopnu(), open(), clgwrd()
+int	access(), btoi(), ap_memstat(), sizeof()
+bool	clgetb(), streq()
+errchk	gopen()
+
+begin
+	# Allocate working space.
+	call smark (sp)
+	call salloc (image, SZ_FNAME, TY_CHAR)
+	call salloc (coords, SZ_FNAME, TY_CHAR)
+	call salloc (polygons, SZ_FNAME, TY_CHAR)
+	call salloc (display, SZ_FNAME, TY_CHAR)
+	call salloc (graphics, SZ_FNAME, TY_CHAR)
+	call salloc (cfname, SZ_FNAME, TY_CHAR)
+	call salloc (pfname, SZ_FNAME, TY_CHAR)
+	call salloc (str, SZ_LINE, TY_CHAR)
+
+	# Set STDOUT.
+	call fseti (STDOUT, F_FLUSHNL, YES)
+
+	# Get input and output file lists.
+	imlist = imtopenp ("image")
+	limlist = imtlen (imlist)
+	plist = clpopnu ("polygons")
+	lplist = clplen (plist)
+	clist = clpopnu ("coords")
+	lclist = clplen (clist)
+
+	# Check that image input and coords file list lengths match.
+	if (lclist > 0 && lclist != limlist) {
+	    call imtclose (imlist)
+	    call clpcls (plist)
+	    call clpcls (clist)
+	    call error (0, "Imcompatible image and coord file list lengths")
+	}
+
+	# Check that image input and polygons file list lengths match.
+	if (lplist != limlist) {
+	    call imtclose (imlist)
+	    call clpcls (plist)
+	    call clpcls (clist)
+	    call error (0, "Imcompatible image and polygons file list lengths")
+	}
+
+	cache = btoi (clgetb ("cache"))
+
+	# Open the graphics device.
+	call clgstr ("graphics", Memc[graphics], SZ_FNAME)
+	if (Memc[graphics] == EOS)
+	    gd = NULL
+	else {
+	    iferr {
+	        gd = gopen (Memc[graphics], APPEND+AW_DEFER, STDGRAPH)
+	    } then {
+		call eprintf  ("Warning: Error opening graphics device.\n")
+		gd = NULL
+	    }
+	}
+
+	# Open the display device.
+	call clgstr ("display", Memc[display], SZ_FNAME)
+	if (Memc[display] == EOS)
+	    id = NULL
+	 else if (streq (Memc[display], Memc[graphics])) {
+	    id = gd
+	 } else {
+	    iferr {
+	        id = gopen (Memc[display], APPEND, STDIMAGE)
+	    } then {
+	        call eprintf (
+		"Warning: Graphics overlay not available for display device.\n")
+		id = NULL
+	    }
+	}
+
+	# Open the polymark structure.
+	call ap_ymkinit (py)
+
+        # Get the wcs information.
+        wcs = clgwrd ("wcsin", Memc[str], SZ_LINE, WCSINSTR)
+        if (wcs <= 0) {
+            call eprintf (
+                "Warning: Setting the input coordinate system to logical\n")
+            wcs = WCS_LOGICAL
+        }
+        call apseti (py, WCSIN, wcs)
+        wcs = clgwrd ("wcsout", Memc[str], SZ_LINE, WCSOUTSTR)
+        if (wcs <= 0) {
+            call eprintf (
+                "Warning: Setting the output coordinate system to logical\n")
+            wcs = WCS_LOGICAL
+        }
+        call apseti (py, WCSOUT, wcs)
+
+	# Mark polygons.
+	while (imtgetim (imlist, Memc[image], SZ_FNAME) != EOF) {
+	    
+	    # Open image.
+	    im = immap (Memc[image], READ_ONLY, 0)
+            call apimkeys (py, im, Memc[image])
+
+	    # Establish the image display viewport and window.
+	    if ((id != NULL) && (id != gd))
+		call ap_gswv (id, Memc[image], im, 4)
+
+	    # Cache the input image pixels.
+            req_size = MEMFUDGE * IM_LEN(im,1) * IM_LEN(im,2) *
+                sizeof (IM_PIXTYPE(im))
+            memstat = ap_memstat (cache, req_size, old_size)
+            if (memstat == YES)
+                call ap_pcache (im, INDEFI, buf_size)
+
+	    # Set the polygon file name.
+	    if (lplist == 0)
+		pl = NULL
+	    else {
+	        stat = clgfil (plist, Memc[polygons], SZ_FNAME)
+		root = fnldir (Memc[polygons], Memc[pfname], SZ_FNAME)
+		if (strncmp ("default", Memc[polygons+root], 7) == 0 || root ==
+		    strlen (Memc[polygons])) {
+		    call apoutname (Memc[image], Memc[pfname], "ver",
+		        Memc[pfname], SZ_FNAME)
+		    lplist = limlist
+		} else if (stat != EOF)
+		    call strcpy (Memc[polygons], Memc[pfname], SZ_FNAME)
+		if (access (Memc[pfname], READ_WRITE, TEXT_FILE) == YES) {
+		    newpy = NO
+		    pl = open (Memc[pfname], READ_WRITE, TEXT_FILE)
+		} else {
+		    newpy = YES
+		    pl = open (Memc[pfname], NEW_FILE, TEXT_FILE)
+		    call close (pl)
+		    pl = open (Memc[pfname], READ_WRITE, TEXT_FILE)
+		}
+	    }
+	    call apsets (py, PYNAME, Memc[pfname])
+
+	    # Set the coord file name.
+	    if (lclist == 0)
+		cl = NULL
+	    else {
+	        stat = clgfil (clist, Memc[coords], SZ_FNAME)
+		root = fnldir (Memc[coords], Memc[cfname], SZ_FNAME)
+		if (strncmp ("default", Memc[coords+root], 7) == 0 || root ==
+		    strlen (Memc[coords])) {
+		    call apoutname (Memc[image], Memc[cfname], "coo",
+		        Memc[cfname], SZ_FNAME)
+		    lclist = limlist
+		} else if (stat != EOF)
+		    call strcpy (Memc[coords], Memc[cfname], SZ_FNAME)
+		if (access (Memc[cfname], READ_WRITE, TEXT_FILE) == YES) {
+		    newcoo = NO
+		    cl = open (Memc[cfname], READ_WRITE, TEXT_FILE)
+		} else {
+		    newcoo = YES
+		    cl = open (Memc[cfname], NEW_FILE, TEXT_FILE)
+		    call close (cl)
+		    cl = open (Memc[cfname], READ_WRITE, TEXT_FILE)
+		}
+	    }
+	    call apsets (py, CLNAME, Memc[cfname])
+
+	    # Mark polygons on each image.
+	    pid = 1
+	    cid = 1
+	    stat = ap_mkpylist (im, py, pl, cl, id, gd, pid, cid)
+
+	    # Unmap the input image.
+	    call imunmap (im)
+
+	    # Close the polygon file.
+	    if (pl != NULL) {
+		call close (pl)
+		if (newpy == YES && pid <= 1)
+		    call delete (Memc[pfname])
+	    }
+
+	    # Close the coordinate file.
+	    if (cl != NULL) {
+		if (cid > 1) {
+		    call seek (cl, EOF)
+		    call fprintf (cl, ";\n")
+		}
+		call close (cl)
+		if (newcoo == YES && cid <= 1)
+		    call delete (Memc[cfname])
+	    }
+
+	    # Uncache memory.
+	    call fixmem (old_size)
+
+	    if (stat == YES)
+		break
+	}
+
+	# Close the graphics and image display devices.
+	if (id == gd && id != NULL)
+	    call gclose (id)
+	else {
+	    if (gd != NULL)
+		call gclose (gd)
+	    if (id != NULL)
+		call gclose (id)
+	}
+
+	# Free the polymark structure.
+	call ap_ymkfree (py)
+
+	# Close image, polygon, and coordinate lists.
+	call imtclose (imlist)
+	call clpcls (plist)
+	call clpcls (clist)
+	call sfree (sp)
+end
diff --git a/noao/digiphot/apphot/polyphot/t_polyphot.x b/noao/digiphot/apphot/polyphot/t_polyphot.x
new file mode 100644
index 00000000..5242d02e
--- /dev/null
+++ b/noao/digiphot/apphot/polyphot/t_polyphot.x
@@ -0,0 +1,329 @@
+include <gset.h>
+include <fset.h>
+include <imhdr.h>
+include "../lib/apphot.h"
+include "../lib/polyphot.h"
+
+# T_POLYPHOT -- Measure the total magnitudes inside a list of polygons.
+
+procedure t_polyphot()
+
+pointer	image			# pointer to name of image
+pointer	output			# pointer to the results file
+pointer	coords			# pointer to file of coordinates
+pointer	polygon			# pointer to file containing polygon
+pointer	graphics		# pointer to graphics device name
+pointer	display			# pointer to display device name
+int	interactive		# mode of use
+int	cache			# cache the input image pixels
+int	verify			# verify critical parameters
+int	update			# update the critical parameters
+int	verbose			# print messages
+
+pointer	sp, outfname, cname, im, py, id, gd, str
+int	limlist, lplist, lolist, lclist, sid, lid, pid, pl, cl, out, root, stat
+int	imlist, plist, olist, clist, memstat, wcs, req_size, old_size, buf_size
+
+pointer	immap(), gopen()
+int	imtlen(), imtgetim(), clplen(), clgfil(), btoi(), strncmp()
+int	fnldir(), strlen(), ap_yphot(), open(), imtopenp(), clpopnu()
+int	clgwrd(), ap_memstat(), sizeof()
+bool	clgetb(), streq()
+errchk	gopen
+
+begin
+	# Allocate working space.
+	call smark (sp)
+	call salloc (image, SZ_FNAME, TY_CHAR)
+	call salloc (output, SZ_FNAME, TY_CHAR)
+	call salloc (coords, SZ_FNAME, TY_CHAR)
+	call salloc (polygon, SZ_FNAME, TY_CHAR)
+	call salloc (graphics, SZ_FNAME, TY_CHAR)
+	call salloc (display, SZ_FNAME, TY_CHAR)
+	call salloc (outfname, SZ_FNAME, TY_CHAR)
+	call salloc (cname, SZ_FNAME, TY_CHAR)
+	call salloc (str, SZ_LINE, TY_CHAR)
+
+	# Set STDOUT.
+	call fseti (STDOUT, F_FLUSHNL, YES)
+
+	# Get input and output file lists.
+	imlist = imtopenp ("image")
+	limlist = imtlen (imlist)
+	plist = clpopnu ("polygons")
+	lplist = clplen (plist)
+	olist = clpopnu ("output")
+	lolist = clplen (olist)
+	clist = clpopnu ("coords")
+	lclist = clplen (clist)
+
+	# Check that image and polygon list lengths match.
+	if (limlist < 1 || (lplist > 1 && lplist != limlist)) {
+	    call imtclose (imlist)
+	    call clpcls (plist)
+	    call clpcls (olist)
+	    call clpcls (clist)
+	    call error (0, "Imcompatible image and polygon list lengths")
+	}
+
+	# Check that image and coordinates list lengths match. 
+	if (limlist < 1 || (lclist > 1 && lclist != limlist)) {
+	    call imtclose (imlist)
+	    call clpcls (plist)
+	    call clpcls (olist)
+	    call clpcls (clist)
+	    call error (0, "Imcompatible image and coordinate list lengths")
+	}
+
+	# Check that image input and output list lengths match.
+	if (lolist > 1 && lolist != limlist) {
+	    call imtclose (imlist)
+	    call clpcls (plist)
+	    call clpcls (olist)
+	    call clpcls (clist)
+	    call error (0, "Imcompatible image and output list lengths")
+	}
+
+	call clgstr ("icommands.p_filename", Memc[cname], SZ_FNAME)
+	if (Memc[cname] != EOS)
+	    interactive = NO
+	else
+	    interactive = btoi (clgetb ("interactive"))
+	cache = btoi (clgetb ("cache"))
+	verify = btoi (clgetb ("verify"))
+	update = btoi (clgetb ("update"))
+	verbose = btoi (clgetb ("verbose"))
+
+	# Get polygon fitting parameters.
+	call ap_gypars (py)
+
+	# Confirm the algorithm parameters.
+	if (verify == YES && interactive == NO) {
+	    call ap_yconfirm (py, NULL, 1)
+	    if (update == YES)
+		call ap_pypars (py)
+	}
+
+        # Get the wcs information.
+        wcs = clgwrd ("wcsin", Memc[str], SZ_LINE, WCSINSTR)
+        if (wcs <= 0) {
+            call eprintf (
+                "Warning: Setting the input coordinate system to logical\n")
+            wcs = WCS_LOGICAL
+        }
+        call apseti (py, WCSIN, wcs)
+        wcs = clgwrd ("wcsout", Memc[str], SZ_LINE, WCSOUTSTR)
+        if (wcs <= 0) {
+            call eprintf (
+                "Warning: Setting the output coordinate system to logical\n")
+            wcs = WCS_LOGICAL
+        }
+        call apseti (py, WCSOUT, wcs)
+
+	# Get the graphics and display devices.
+	call clgstr ("graphics", Memc[graphics], SZ_FNAME)
+	call clgstr ("display", Memc[display], SZ_FNAME)
+
+	# Open the plot files.
+	if (interactive == YES) {
+	    if (Memc[graphics] == EOS)
+		gd = NULL
+	    else {
+		iferr {
+		    gd = gopen (Memc[graphics], APPEND+AW_DEFER, STDGRAPH)
+		} then {
+		    call eprintf (
+			"Warning: Error opening graphics device.\n")
+		    gd = NULL
+		}
+	    }
+	    if (Memc[display] == EOS)
+		id = NULL
+	    else if (streq (Memc[graphics], Memc[display]))
+		id = gd
+	    else {
+		iferr {
+		    id = gopen (Memc[display], APPEND, STDIMAGE)
+		} then {
+		    call eprintf (
+		"Warning: Graphics overlay not available for display device.\n")
+		    id = NULL
+		}
+	    }
+	} else {
+	    gd = NULL
+	    id = NULL
+	}
+
+	# Measure flux in a polygon.
+	sid = 1
+	while (imtgetim (imlist, Memc[image], SZ_FNAME) != EOF) {
+	    
+	    # Open image.
+	    im = immap (Memc[image], READ_ONLY, 0)
+	    call apimkeys (py, im, Memc[image])
+	    if ((id != NULL) && (id != gd))
+		call ap_gswv (id, Memc[image], im, 4)
+
+	    # Cache the input image pixels.
+            req_size = MEMFUDGE * IM_LEN(im,1) * IM_LEN(im,2) *
+                sizeof (IM_PIXTYPE(im))
+            memstat = ap_memstat (cache, req_size, old_size)
+            if (memstat == YES)
+                call ap_pcache (im, INDEFI, buf_size)
+
+	    # Open the polygons file.
+	    if (lplist <= 0) {
+		pl = NULL
+		call strcpy ("", Memc[outfname], SZ_FNAME)
+	    } else {
+		stat = clgfil (plist, Memc[polygon], SZ_FNAME)
+		root = fnldir (Memc[polygon], Memc[outfname], SZ_FNAME)
+		if (strncmp ("default", Memc[polygon+root], 7) == 0 || root ==
+		    strlen (Memc[polygon])) {
+		    call ap_inname (Memc[image], Memc[outfname], "ver",
+		        Memc[outfname], SZ_FNAME)
+		    lplist = limlist
+		    pl = open (Memc[outfname], READ_ONLY, TEXT_FILE)
+		} else if (stat != EOF) {
+		    call strcpy (Memc[polygon], Memc[outfname], SZ_FNAME)
+		    pl = open (Memc[outfname], READ_ONLY, TEXT_FILE)
+		} else {
+		    call apstats (py, PYNAME, Memc[outfname], SZ_FNAME)
+		    call seek (pl, BOF)
+		}
+	    }
+	    call apsets (py, PYNAME, Memc[outfname])
+	    call apfroot (Memc[outfname], Memc[str], SZ_LINE)
+	    call apsets (py, PYROOT, Memc[str])
+
+	    # Open the coordinates file.
+	    if (lclist <= 0) {
+		cl = NULL
+		call strcpy ("", Memc[outfname], SZ_FNAME)
+	    } else {
+		stat = clgfil (clist, Memc[coords], SZ_FNAME)
+		root = fnldir (Memc[coords], Memc[outfname], SZ_FNAME)
+		if (strncmp ("default", Memc[coords+root], 7) == 0 || root ==
+		    strlen (Memc[coords])) {
+		    call ap_inname (Memc[image], Memc[outfname], "coo",
+		        Memc[outfname], SZ_FNAME)
+		    lclist = limlist
+	            cl = open (Memc[outfname], READ_ONLY, TEXT_FILE)
+		} else if (stat != EOF) {
+		    call strcpy (Memc[coords], Memc[outfname], SZ_FNAME)
+	            cl = open (Memc[outfname], READ_ONLY, TEXT_FILE)
+		} else {
+		    call apstats (py, CLNAME, Memc[outfname], SZ_FNAME)
+		    call seek (cl, BOF)
+		}
+	    }
+	    call apsets (py, CLNAME, Memc[outfname])
+	    call apfroot (Memc[outfname], Memc[str], SZ_LINE)
+	    call apsets (py, CLROOT, Memc[str])
+
+	    # Set output file name.
+	    if (lolist == 0) {
+		out = NULL
+		call strcpy ("", Memc[outfname], SZ_FNAME)
+	    } else {
+	        stat = clgfil (olist, Memc[output], SZ_FNAME)
+		root = fnldir (Memc[output], Memc[outfname], SZ_FNAME)
+		if (strncmp ("default", Memc[output+root], 7) == 0 || root ==
+		    strlen (Memc[output])) {
+		    call apoutname (Memc[image], Memc[outfname], "ply",
+		        Memc[outfname], SZ_FNAME)
+		    out = open (Memc[outfname], NEW_FILE, TEXT_FILE)
+		    lolist = limlist
+		} else if (stat != EOF) {
+		    call strcpy (Memc[output], Memc[outfname], SZ_FNAME)
+		    out = open (Memc[outfname], NEW_FILE, TEXT_FILE)
+		} else
+		    call apstats (py, OUTNAME, Memc[outfname], SZ_FNAME)
+	    }
+	    call apsets (py, OUTNAME, Memc[outfname])
+
+	    # Do the photometry.
+	    if (interactive == NO) {
+		if (Memc[cname] != EOS)
+		    stat = ap_yphot (py, im, cl, pl, NULL, NULL, out, sid, NO,
+			cache)
+		else if (pl != NULL) {
+		    lid = 0
+		    pid = 0
+		    call ap_ybphot (py, im, cl, pl, out, sid, lid, pid, NULL,
+		        verbose)
+		    stat = NO
+		} else
+		    stat = NO
+	    } else
+		stat = ap_yphot (py, im, cl, pl, gd, id, out, sid, YES, cache)
+
+	    # Unmap the input image.
+	    call imunmap (im)
+
+	    # Close the polygon file.
+	    if (pl != NULL) {
+		if (lplist > 1)
+		    call close (pl)
+	    }
+
+	    # Close the coordinate file.
+	    if (cl != NULL) {
+		if (lclist > 1)
+		    call close (cl)
+	    }
+
+	    # Close the output file.
+	    if (out != NULL && lolist != 1) {
+		call close (out)
+		if (sid <= 1) {
+		    call apstats (py, OUTNAME, Memc[outfname], SZ_FNAME)
+		    call delete (Memc[outfname])
+		}
+		sid = 1
+	    }
+
+	    # Uncache memory.
+	    call fixmem (old_size)
+
+	    if (stat == YES)
+		break
+	}
+
+	# Close plot files.
+	if (id == gd && id != NULL)
+	    call gclose (id)
+	else {
+	    if (gd != NULL)
+		call gclose (gd)
+	   if (id != NULL)
+	        call gclose (id)
+	}
+
+	# Close the single coords and polygon file.
+	if (pl != NULL && lplist == 1)
+	    call close (pl)
+	if (cl != NULL && lclist == 1)
+	    call close (cl)
+
+	# Close the singled output file.
+        if (out != NULL && lolist == 1) {
+	    call close (out)
+	    if (sid <= 1) {
+		call apstats (py, OUTNAME, Memc[outfname], SZ_FNAME)
+		call delete (Memc[outfname])
+	    }
+	}
+
+	# Close up the files.
+	call ap_yfree (py)
+
+	# Close image, coord and shift lists.
+	call imtclose (imlist)
+	call clpcls (plist)
+	call clpcls (clist)
+	call clpcls (olist)
+
+	call sfree (sp)
+end
diff --git a/noao/digiphot/apphot/qphot.par b/noao/digiphot/apphot/qphot.par
new file mode 100644
index 00000000..85b18882
--- /dev/null
+++ b/noao/digiphot/apphot/qphot.par
@@ -0,0 +1,27 @@
+# QPHOT parameters
+
+image,f,a,,,,"The input image(s)"
+cbox,r,a,5.0,,,"The centering box width in pixels"
+annulus,r,a,,0.0,,"The inner radius of sky annulus in pixels"
+dannulus,r,a,,1.0,,"The width of the sky annulus in pixels"
+apertures,s,a,"3.0",,,"The list of photometry apertures"
+coords,s,h,"",,,"The input coordinate file(s) (default: *.coo.?)"
+output,f,h,"default",,,"The output photometry file(s) (default: *.mag.?)"
+plotfile,f,h,"",,,"The output plot metacode file"
+zmag,r,h,25.0,,,"The zero point of the magnitude scale"
+exposure,s,h,"",,,"The exposure time image header keyword"
+airmass,s,h,"",,,"The airmass image header keyword"
+filter,s,h,"",,,"The filter image header keyword"
+obstime,s,h,"",,,"The time of observation image header keyword"
+epadu,r,h,1.0,,,"The instrument gain in e-/ADU"
+interactive,b,h,yes,,,"Interactive mode ?"
+radplots,b,h,no,,,"Plot the radial profiles in interactive mode ?"
+icommands,*imcur,h,"",,,"Image cursor: [x y wcs] key [cmd]"
+gcommands,*gcur,h,"",,,"Graphics cursor: [x y wcs] key [cmd]"
+wcsin,s,h,)_.wcsin,,,"The input coordinate system (logical,tv,physical,world)"
+wcsout,s,h,)_.wcsout,,,"The output coordinate system (logical,tv,physical)"
+cache,b,h,)_.cache,,,"Cache input image pixels in memory ?"
+verbose,b,h,)_.verbose,,,"Print messages in non-interactive mode ?"
+graphics,s,h,)_.graphics,,,"Graphics device"
+display,s,h,)_.display,,,"Display device"
+mode,s,h,'ql'
diff --git a/noao/digiphot/apphot/radprof.par b/noao/digiphot/apphot/radprof.par
new file mode 100644
index 00000000..c5ce3bb7
--- /dev/null
+++ b/noao/digiphot/apphot/radprof.par
@@ -0,0 +1,28 @@
+# RADPROF
+
+image,f,a,,,,"The input image(s)"
+radius,r,a,,,,"The maximum radial profile radius in scale units"
+step,r,a,,,,"The step size for radial profile in scale units"
+coords,f,h,"",,,"The input coordinate list(s) (default: image.coo.?)"
+output,f,h,"",,,"The output radial profile files (default: image.prf.?)"
+plotfile,f,h,"",,,"The output radial profile plot metacode file"
+datapars,pset,h,"",,,"Data dependent parameters"
+centerpars,pset,h,"",,,"Centering parameters"
+fitskypars,pset,h,"",,,"Sky fitting parameters"
+photpars,pset,h,"",,,"Photometry parameters"
+order,i,h,5,1,,"Order of spline fit"
+kreject,r,h,3.0,,,"K-sigma rejection limit"
+nreject,i,h,1,,,"Maximum number of rejection cycles"
+interactive,b,h,yes,,,"Interactive mode ?"
+radplots,b,h,yes,,,"Plot radial profiles in interactive mode ?"
+icommands,*imcur,h,"",,,"Image cursor: [x y wcs] key [cmd]"
+gcommands,*gcur,h,"",,,"Graphics cursor: [x y wcs] key [cmd]"
+wcsin,s,h,)_.wcsin,,,"The input coordinate system (logical,tv,physical,world)"
+wcsout,s,h,)_.wcsout,,,"The output coordinate system (logical,tv,physical)"
+cache,b,h,)_.cache,,,"Cache the input image pixels ?"
+verify,b,h,)_.verify,,,"Verify critical parameters in non-interactive mode ?"
+update,b,h,)_.update,,,"Update critical parameters in non-interactive mode ?"
+verbose,b,h,)_.verbose,,,"Print messages in non-interactive mode ?"
+graphics,s,h,)_.graphics,,,"Graphics device"
+display,s,h,)_.display,,,"Image display device"
+mode,s,h,'ql'
diff --git a/noao/digiphot/apphot/radprof/apbradprof.x b/noao/digiphot/apphot/radprof/apbradprof.x
new file mode 100644
index 00000000..08e5547b
--- /dev/null
+++ b/noao/digiphot/apphot/radprof/apbradprof.x
@@ -0,0 +1,107 @@
+include <fset.h>
+include "../lib/apphot.h"
+include "../lib/display.h"
+include "../lib/center.h"
+include "../lib/fitsky.h"
+
+# AP_BRADPROF -- Procedure to fit the radial profiles of a list of objects
+# in a list of images.
+
+procedure ap_bradprof (ap, im, cl, gid, gd, mgd, out, id, ld, interactive)
+
+pointer ap			# pointer to apphot structure
+pointer	im			# pointer to IRAF image
+int	cl			# starlist file descriptor
+pointer	gid			# display device stream
+pointer	gd			# pointer to graphics stream
+pointer	mgd			# pointer to metacode file
+int	out			# output file descriptor
+int	id, ld			# sequence and list numbers
+int	interactive		# interactive pr batch mode
+
+int	stdin, ild, cier, sier, pier, rier
+pointer	sp, str
+real	wx, wy
+int	fscan(), nscan(), apfitsky(), apfitcenter(), ap_frprof(), apstati()
+int	strncmp()
+real	apstatr()
+
+begin
+	call smark (sp)
+	call salloc (str, SZ_FNAME + 1, TY_CHAR)
+	call fstats (cl, F_FILENAME, Memc[str], SZ_FNAME)
+
+	# Initialize.
+	ild = ld
+
+	# Print query if coords is equal to STDIN.
+	if (strncmp ("STDIN", Memc[str], 5) == 0) {
+	    stdin = YES
+	    call printf (
+	    "Type x and y coordinates of object (^D or ^Z to end): ")
+	    call flush (STDOUT)
+	} else
+	    stdin = NO
+
+	# Loop over the coordinate file.
+	while (fscan (cl) != EOF) {
+
+	    # Get the coordinates.
+	    call gargr (wx)
+	    call gargr (wy)
+	    if (nscan () != 2) {
+		if (stdin == YES) {
+	    	    call printf (
+		    "Type x and y coordinates of object (^D or ^Z to end): ")
+	    	    call flush (STDOUT)
+		}
+		next
+	    }
+
+            # Transform the input coordinates.
+            switch (apstati(ap,WCSIN)) {
+            case WCS_WORLD, WCS_PHYSICAL:
+                call ap_itol (ap, wx, wy, wx, wy, 1)
+            case WCS_TV:
+                call ap_vtol (im, wx, wy, wx, wy, 1)
+            default:
+                ;
+            }
+
+	    # Set the current cursor position.
+	    call apsetr (ap, CWX, wx)
+	    call apsetr (ap, CWY, wy)
+
+	    # Fit the center, sky and radial profile.
+	    cier = apfitcenter (ap, im, wx, wy)
+	    sier = apfitsky (ap, im, apstatr (ap, XCENTER), apstatr (ap,
+	        YCENTER), NULL, gd)
+	    rier = ap_frprof (ap, im, apstatr (ap, XCENTER), apstatr (ap,
+		YCENTER), pier)
+
+	    # Output the results.
+	    if (interactive == YES) {
+		call ap_qprprof (ap, cier, sier, pier, rier)
+		if (id != NULL)
+		    call aprmark (ap, gid, apstati (ap, MKCENTER),
+		        apstati (ap, MKSKY), apstati (ap, MKAPERT))
+	    }
+	    if (id == 1)
+	        call ap_param (ap, out, "radprof")
+	    call ap_prprof (ap, out, id, ild, cier, sier, pier, rier)
+	    call ap_rpplot (ap, id, mgd, YES)
+
+	    # Setup for the next object.
+	    id = id + 1
+	    ild = ild + 1
+	    call apsetr (ap, WX, wx)
+	    call apsetr (ap, WY, wy)
+	    if (stdin == YES) {
+	        call printf (
+		"Type x and y coordinates of object (^D or ^Z to end): ")
+	        call flush (STDOUT)
+	    }
+	}
+
+	call sfree (sp)
+end
diff --git a/noao/digiphot/apphot/radprof/apfrprof.x b/noao/digiphot/apphot/radprof/apfrprof.x
new file mode 100644
index 00000000..093e90bd
--- /dev/null
+++ b/noao/digiphot/apphot/radprof/apfrprof.x
@@ -0,0 +1,417 @@
+include <mach.h>
+include <gset.h>
+include <math.h>
+
+include <math/curfit.h>
+include <math/iminterp.h>
+include "../lib/apphotdef.h"
+include "../lib/noisedef.h"
+include "../lib/fitskydef.h"
+include "../lib/photdef.h"
+include "../lib/radprofdef.h"
+include "../lib/apphot.h"
+include "../lib/phot.h"
+include "../lib/radprof.h"
+
+# AP_FRPROF -- Compute the radial profile of an object.
+
+int procedure ap_frprof (ap, im, wx, wy, pier)
+
+pointer	ap		# pointer to the apphot structure
+pointer	im		# pointer to the IRAF image
+real	wx, wy		# object coordinates
+int	pier		# photometry error
+
+int	i, ier, fier, nxpts, nypts, nrpts, order
+pointer	sky, rprof, cv, asi
+real	datamin, datamax, step, rmin, rmax, inorm, tinorm
+int	ap_rpbuf(), ap_rmag(), ap_rpmeasure(), ap_rpiter()
+real	asigrl(), cveval(), ap_rphalf()
+
+errchk	cvinit(), cvfit(), cvvector(), cveval(), cvfree()
+errchk	asinit(), asifit(), asigrl(), asifree()
+errchk	ap_rpmeasure(), ap_rpiter()
+
+begin
+	# Set up some apphot pointers.
+	sky = AP_PSKY(ap)
+	rprof = AP_RPROF(ap)
+
+	# Initialize.
+         AP_RPXCUR(rprof) = wx
+         AP_RPYCUR(rprof) = wy
+	call ap_rpindef (ap)
+        if (IS_INDEFR(wx) || IS_INDEFR(wy)) {
+            AP_ORPXCUR(rprof) = INDEFR
+            AP_ORPYCUR(rprof) = INDEFR
+        } else {
+            switch (AP_WCSOUT(ap)) {
+            case WCS_WORLD, WCS_PHYSICAL:
+                call ap_ltoo (ap, wx, wy, AP_ORPXCUR(rprof),
+		    AP_ORPYCUR(rprof), 1)
+            case WCS_TV:
+                call ap_ltov (im, wx, wy, AP_ORPXCUR(rprof),
+		    AP_ORPYCUR(rprof), 1)
+            default:
+                AP_ORPXCUR(rprof) = wx
+                AP_ORPYCUR(rprof) = wy
+            }
+        }
+
+	# Get the pixels and check for error conditions.
+	if (IS_INDEFR(wx) || IS_INDEFR(wy)) {
+	    pier = AP_APERT_NOAPERT
+	    return (AP_RP_NOPROFILE)
+	} else if (IS_INDEFR(AP_SKY_MODE(sky))) {
+	    pier = AP_APERT_NOSKYMODE
+	    return (AP_RP_NOSKYMODE)
+	} else if (ap_rpbuf (ap, im, wx, wy) == AP_RP_NOPROFILE) {
+	    pier = AP_APERT_NOAPERT
+	    return (AP_RP_NOPROFILE)
+	}
+
+	# Do the photometry.
+	pier = ap_rmag (ap)
+
+	# Initialize some common variables.
+	nxpts = AP_RPNX(rprof)
+	nypts = AP_RPNY(rprof)
+	nrpts = AP_RPNPTS(rprof)
+
+	# Initialize the radial profile curve fitting.
+	step = AP_SCALE(ap) * AP_RPSTEP(rprof)
+	order = max (1, min (AP_RPORDER(rprof), nxpts * nypts - 3))
+	rmin = 0.0
+	rmax = (nrpts - 1) * step
+	if (IS_INDEFR(AP_DATAMIN(ap)))
+	    datamin = -MAX_REAL
+	else
+	    datamin = AP_DATAMIN(ap) - AP_SKY_MODE(sky)
+	if (IS_INDEFR(AP_DATAMAX(ap)))
+	    datamax = MAX_REAL
+	else
+	    datamax = AP_DATAMAX(ap) - AP_SKY_MODE(sky)
+
+	# Fit the curve.
+	call cvinit (cv, SPLINE3, order, rmin, rmax) 
+	call asubkr (Memr[AP_RPIX(rprof)], AP_SKY_MODE(sky),
+	    Memr[AP_RPIX(rprof)], nxpts * nypts)
+	fier = ap_rpmeasure (cv, Memr[AP_RPIX(rprof)], nxpts, nypts,
+	    AP_RPXC(rprof), AP_RPYC(rprof), datamin, datamax, rmax,
+	    AP_RPNDATA(rprof), AP_RPNBAD(rprof))
+
+	# Perform the rejection cycle.
+	if (fier != NO_DEG_FREEDOM && AP_RPNREJECT(rprof) > 0 &&
+	    AP_RPKSIGMA(rprof) > 0.0)
+	    AP_RPNDATAREJ(rprof) = ap_rpiter (cv, Memr[AP_RPIX(rprof)], nxpts,
+	        nypts, AP_RPXC(rprof), AP_RPYC(rprof), rmax, datamin, datamax,
+		AP_RPNREJECT(rprof), AP_RPKSIGMA(rprof), fier)
+	else
+	    AP_RPNDATAREJ(rprof) = 0
+
+	AP_RPNDATA(rprof) = AP_RPNDATA(rprof) - AP_RPNDATAREJ(rprof)
+	AP_RPNDATAREJ(rprof) = AP_RPNDATAREJ(rprof) + AP_RPNBAD(rprof)
+
+	# Evaluate the fit.
+	if (fier != NO_DEG_FREEDOM) {
+
+	    # Evaluate the profile.
+	    do i = 1, nrpts
+	        Memr[AP_RPDIST(rprof)+i-1] = (i - 1) * step
+	    call cvvector (cv, Memr[AP_RPDIST(rprof)],
+	        Memr[AP_INTENSITY(rprof)], nrpts)
+
+	    # Evaluate the integral.
+	    call asiinit (asi, II_SPLINE3)
+	    call amulr (Memr[AP_RPDIST(rprof)], Memr[AP_INTENSITY(rprof)],
+	        Memr[AP_TINTENSITY(rprof)], nrpts)
+	    call asifit (asi, Memr[AP_TINTENSITY(rprof)], nrpts)
+	    Memr[AP_TINTENSITY(rprof)] = 0.0
+	    do i = 2, nrpts
+	        Memr[AP_TINTENSITY(rprof)+i-1] = Memr[AP_TINTENSITY(rprof)+
+		    i-2] + asigrl (asi, real (i - 1), real (i))
+	    call amulkr (Memr[AP_TINTENSITY(rprof)], real (TWOPI) * step,
+	        Memr[AP_TINTENSITY(rprof)], nrpts)
+	    call asifree (asi)
+
+	    # Normalize the radial profile.
+	    inorm = cveval (cv, 0.0)
+	    if (inorm != 0.0)
+	        call adivkr (Memr[AP_INTENSITY(rprof)], inorm,
+	            Memr[AP_INTENSITY(rprof)], nrpts)
+	    call apsetr (ap, INORM, inorm)
+
+	    # Normalize the total intensity.
+	    tinorm = Memr[AP_TINTENSITY(rprof)+AP_RPNPTS(rprof)-1]
+	    if (tinorm != 0.0)
+	        call adivkr (Memr[AP_TINTENSITY(rprof)], tinorm,
+	            Memr[AP_TINTENSITY(rprof)], nrpts)
+	    call apsetr (ap, TNORM, tinorm)
+
+	    # Compute the FWHMPSF.
+	    call apsetr (ap, RPFWHM, 2.0 * ap_rphalf (Memr[AP_RPDIST(rprof)],
+	        Memr[AP_INTENSITY(rprof)], nrpts))
+	}
+
+	# Set the error code and return.
+	call cvfree (cv)
+	if (fier == NO_DEG_FREEDOM)
+	    ier = AP_RP_NPTS_TOO_SMALL
+	else if (fier == SINGULAR)
+	    ier = AP_RP_SINGULAR
+
+	# Free space.
+	return (ier)
+end
+
+
+# AP_RMAG -- Compute the magnitudes for the radial profile
+
+int procedure ap_rmag (ap)
+
+pointer	ap		# pointer to the apphot structure
+
+int	pier, nap
+pointer	sp, nse, sky, phot, rprof, aperts
+real	datamin, datamax, zmag
+
+begin
+	# Initialize some apphot pointers.
+	nse = AP_NOISE(ap)
+	sky = AP_PSKY(ap)
+	phot = AP_PPHOT(ap)
+	rprof = AP_RPROF(ap)
+
+	# Allocate working space.
+	call smark (sp)
+	call salloc (aperts, AP_NAPERTS(phot), TY_REAL)
+
+	# Check for out of bounds apertures.
+	call ap_maxap (ap, pier)
+
+	# Define the good data minimum and maximum for photometry.
+	if (IS_INDEFR(AP_DATAMIN(ap)))
+	    datamin = -MAX_REAL
+	else
+	    datamin = AP_DATAMIN(ap)
+	if (IS_INDEFR(AP_DATAMAX(ap)))
+	    datamax = MAX_REAL
+	else
+	    datamax = AP_DATAMAX(ap)
+
+	# Compute the sums.
+	call ap_arrayr (ap, APERTS, Memr[aperts])
+	call amulkr (Memr[aperts], AP_SCALE(ap), Memr[aperts], AP_NAPERTS(phot))
+	if (IS_INDEFR(AP_DATAMIN(ap)) && IS_INDEFR(AP_DATAMAX(ap))) {
+	    call ap_rmmeasure (Memr[AP_RPIX(rprof)], AP_RPNX(rprof),
+	        AP_RPNY(rprof), AP_RPXC(rprof), AP_RPYC(rprof), Memr[aperts],
+		Memd[AP_SUMS(phot)], Memd[AP_AREA(phot)], AP_NMAXAP(phot))
+	    AP_NMINAP(phot) = AP_NMAXAP(phot) + 1
+	} else
+	    call ap_brmmeasure (Memr[AP_RPIX(rprof)], AP_RPNX(rprof),
+	        AP_RPNY(rprof), AP_RPXC(rprof), AP_RPYC(rprof), datamin,
+		datamax, Memr[aperts], Memd[AP_SUMS(phot)],
+		Memd[AP_AREA(phot)], AP_NMAXAP(phot), AP_NMINAP(phot))
+
+	# Check for bad pixels.
+	if ((pier == AP_OK) && (AP_NMINAP(phot) <= AP_NMAXAP(phot)))
+	    pier = AP_APERT_BADDATA
+	nap = min (AP_NMINAP(phot) - 1, AP_NMAXAP(phot))
+
+	# Compute the magnitudes.
+	zmag = AP_ZMAG(phot) + 2.5 * log10 (AP_ITIME(ap))
+	if (AP_POSITIVE(ap) == YES)
+	    call apcopmags (Memd[AP_SUMS(phot)], Memd[AP_AREA(phot)],
+	        Memr[AP_MAGS(phot)], Memr[AP_MAGERRS(phot)], nap,
+		AP_SKY_MODE(sky), AP_SKY_SIG(sky), AP_NSKY(sky), zmag,
+		AP_NOISEFUNCTION(nse), AP_EPADU(nse))
+	else
+	    call apconmags (Memd[AP_SUMS(phot)], Memd[AP_AREA(phot)],
+	        Memr[AP_MAGS(phot)], Memr[AP_MAGERRS(phot)], nap,
+		AP_SKY_MODE(sky), AP_SKY_SIG(sky), AP_NSKY(sky), zmag,
+		AP_NOISEFUNCTION(nse), AP_EPADU(nse), AP_READNOISE(nse))
+
+	call sfree (sp)
+
+	return (pier)
+end
+
+
+# AP_RPMEASURE -- Procedure to measure the flux and effective area in a set of
+# apertures and accumulate the fit to the radial profile.
+
+int procedure ap_rpmeasure (cv, pixels, nx, ny, wx, wy, datamin, datamax,
+	rmax, ndata, nbad)
+
+pointer	cv			# pointer to curfit structure
+real	pixels[nx,ARB]		# subraster pixel values
+int	nx, ny			# dimensions of the subraster
+real	wx, wy			# center of subraster
+real	datamin			# minimum good data value
+real	datamax			# maximum good data value
+real	rmax			# the maximum radius
+int	ndata			# the number of ok data points
+int	nbad			# the number of bad data points
+
+int	i, j, ier
+real	weight, dy2, r2, rcv
+
+begin
+	# Initialize.
+	ndata = 0
+	nbad = 0
+	call cvzero (cv)
+
+	# Loop over the pixels.
+	do j = 1, ny {
+	    dy2 = (j - wy) ** 2
+	    do i = 1, nx {
+		r2 = (i - wx) ** 2 + dy2
+		rcv = sqrt (r2)
+		if (rcv > rmax)
+		    next
+		if (pixels[i,j] < datamin || pixels[i,j] > datamax) {
+		    nbad = nbad + 1
+		} else {
+		    call cvaccum (cv, rcv, pixels[i,j], weight, WTS_UNIFORM)
+		    ndata = ndata + 1
+		}
+	    }
+	}
+
+	call cvsolve (cv, ier)
+	return (ier)
+end
+
+
+# AP_RPITER -- Procedure to reject pixels from the fit.
+
+int procedure ap_rpiter (cv, pixels, nx, ny, wx, wy, rmax, datamin, datamax,
+	niter, ksigma, fier)
+
+pointer	cv		# pointer to the curfit structure
+real	pixels[nx,ARB]	# pixel values
+int	nx, ny		# dimensions of image subraster
+real	wx, wy		# x and y coordinates of the center
+real	rmax		# maximum radius value
+real	datamin		# minimum good data value
+real	datamax		# maximum good data value
+int	niter		# maximum number of rejection cycles
+real	ksigma		# ksigma rejection limit
+int	fier		# fitting error code
+
+int	i, j, k, npts, ntreject, nreject
+pointer	sp, rtemp, w, ptr
+real	chisqr, diff, locut, hicut
+real	cveval()
+errchk	cveval, cvrject, cvsolve
+
+begin
+	# Allocate the necessary space.
+	call smark (sp)
+	call salloc (rtemp, nx, TY_REAL)
+	call salloc (w, nx * ny, TY_REAL)
+	call amovkr (1.0, Memr[w], nx * ny)
+
+	# Set the weights of out of range and bad data points to 0.0.
+	ptr = w
+	do j = 1, ny {
+	    call ap_ijtor (Memr[rtemp], nx, j, wx, wy)
+	    do k = 1, nx {
+		if (Memr[rtemp+k-1] > rmax || pixels[k,j] < datamin ||
+		    pixels[k,j] > datamax)
+		    Memr[ptr+k-1] = 0.0
+	    }
+	    ptr = ptr + nx
+	}
+
+	ntreject = 0
+	do i = 1, niter { 
+
+	    # Compute the chisqr.
+	    chisqr = 0.0
+	    npts = 0
+	    ptr = w
+	    do j = 1, ny {
+	    	call ap_ijtor (Memr[rtemp], nx, j, wx, wy)
+		do k = 1, nx {
+		    if (Memr[ptr+k-1] <= 0.0)
+			next
+		    chisqr = chisqr + (pixels[k,j] - cveval (cv,
+		        Memr[rtemp+k-1])) ** 2
+		    npts = npts + 1
+		}
+		ptr = ptr + nx
+	    }
+
+	    # Compute the new limits.
+	    if (npts > 1)
+	        chisqr = sqrt (chisqr / (npts - 1))
+	    else
+		chisqr = 0.0
+	    locut = - ksigma * chisqr
+	    hicut = ksigma * chisqr
+
+	    # Reject pixels from the fit.
+	    nreject = 0
+	    ptr = w
+	    do j = 1, ny {
+	    	call ap_ijtor (Memr[rtemp], nx, j, wx, wy)
+		do k = 1, nx {
+		    if (Memr[ptr+k-1] <= 0.0)
+			next
+		    diff = pixels[k,j] - cveval (cv, Memr[rtemp+k-1])
+		    if (diff >= locut && diff <= hicut)
+			next
+		    call cvrject (cv, Memr[rtemp+k-1], pixels[k,j], 1.0)
+		    nreject = nreject + 1
+		    Memr[ptr+k-1] = 0.0
+		}
+		ptr = ptr + nx
+	    }
+
+	    if (nreject == 0)
+	        break
+	    ntreject = ntreject + nreject
+
+	    # Recompute the fit.
+	    call cvsolve (cv, fier)
+	    if (fier == NO_DEG_FREEDOM)
+		break
+	}
+
+
+	call sfree (sp)
+
+	return (ntreject)
+end
+
+
+# AP_RPHALF -- Compute the FWHM of the PSF.
+
+real procedure ap_rphalf (radius, intensity, npts)
+
+real	radius[ARB]		# radius in pixels
+real	intensity[ARB]		# profile intensity
+int	npts			# number of points
+
+int	i
+real	halfp
+
+begin
+	# Seach for the appropriate interval.
+	do i = 1, npts
+	    if (intensity[i] < 0.5)
+		break
+
+	# Compute the full width half maximum.
+	if (i == 1)
+	    halfp = radius[1]
+	else if (i == npts && intensity[npts] >= 0.5)
+	    halfp = radius[npts]
+	else
+	    halfp = (radius[i] * (0.5 - intensity[i-1]) + radius[i-1] *
+		(intensity[i] - 0.5)) / (intensity[i] - intensity[i-1])
+
+	return (halfp)
+end
diff --git a/noao/digiphot/apphot/radprof/apgrpars.x b/noao/digiphot/apphot/radprof/apgrpars.x
new file mode 100644
index 00000000..c7442121
--- /dev/null
+++ b/noao/digiphot/apphot/radprof/apgrpars.x
@@ -0,0 +1,46 @@
+include "../lib/display.h"
+include "../lib/noise.h"
+include "../lib/center.h"
+include "../lib/fitsky.h"
+include "../lib/phot.h"
+include "../lib/radprof.h"
+
+# AP_GRPPARS -- Procedure to fetch the radprof parameters.
+
+procedure ap_grppars (ap)
+
+pointer	ap		# pointer to apphot structure
+
+bool	clgetb()
+int	clgeti(), btoi()
+real	clgetr()
+
+begin
+	# Open the apphot strucuture.
+	call ap_rpinit (ap, AP_CENTROID1D, 2.5, AP_MODE, 10.0, 10.0,
+	        3.0, 1, 8.0, 0.5, 2.0, AP_NPOISSON) 
+
+	# Get the radial profile parameters.
+	call apsetr (ap, RPRADIUS, clgetr ("radius"))
+	call apsetr (ap, RPSTEP, clgetr ("step"))
+
+	# Get the data dependent parameters.
+	call ap_gdapars (ap)
+
+	# Get the centering algorithm parameters.
+	call ap_gcepars (ap)
+
+	# Get the sky fitting algorithm parameters.
+	call ap_gsapars (ap)
+
+	# Get the photometry parameters.
+	call ap_gphpars (ap)
+
+	# Set remainder of the radprof parameters.
+	call apsetr (ap, RPKSIGMA, clgetr ("kreject"))
+	call apseti (ap, RPNREJECT, clgeti ("nreject"))
+	call apseti (ap, RPORDER, clgeti ("order"))
+
+	# Set the plotting parameters.
+	call apseti (ap, RADPLOTS, btoi (clgetb ("radplots")))
+end
diff --git a/noao/digiphot/apphot/radprof/approfsetup.x b/noao/digiphot/apphot/radprof/approfsetup.x
new file mode 100644
index 00000000..826bdd21
--- /dev/null
+++ b/noao/digiphot/apphot/radprof/approfsetup.x
@@ -0,0 +1,123 @@
+include "../lib/display.h"
+include "../lib/center.h"
+include "../lib/fitsky.h"
+
+define	HELPFILE	"apphot$radprof/iradprof.key"
+
+# AP_PROFSETUP -- Procedure to set up radprof interactively using a radial
+# profile plot.
+
+procedure ap_profsetup (ap, im, wx, wy, gd, out, stid)
+
+pointer	ap			# pointer to apphot structure
+pointer	im			# pointer to the IRAF image
+real	wx, wy			# cursor coordinates
+pointer	gd			# pointer to graphics stream
+int	out			# output file descriptor
+int	stid			# output file sequence number
+
+int	cier, sier, pier, rier, wcs, key
+pointer	sp, str, cmd
+real	xc, yc, xcenter, ycenter, rmin, rmax, imin, imax, rval
+real	u1, u2, v1, v2, x1, x2, y1, y2
+
+int	apfitcenter(), clgcur(), apfitsky(), ap_frprof(), apstati()
+int	ap_showplot()
+real	apstatr(), ap_cfwhmpsf(), ap_ccapert(), ap_cannulus(), ap_cdannulus()
+real	ap_crprof(), ap_crpstep(), ap_cdatamin()
+real	ap_cdatamax(), ap_crgrow(), ap_crclip(), ap_crclean(), ap_csigma()
+
+begin
+	if (gd == NULL)
+	    return
+	call greactivate (gd, 0)
+
+	# Save old viewport and window
+	call ggview (gd, u1, u2, v1, v2)
+	call ggwind (gd, x1, x2, y1, y2)
+
+	# Plot the radial profile.
+	if (ap_showplot (ap, im, wx, wy, gd, xcenter, ycenter, rmin, rmax,
+	    imin, imax) == ERR) {
+	    call gdeactivate (gd, 0)
+	    return
+	}
+
+	call smark (sp)
+	call salloc (str, SZ_LINE, TY_CHAR)
+	call salloc (cmd, SZ_LINE, TY_CHAR)
+        call printf (
+        "Waiting for setup menu command (?=help, v=default setup, q=quit):\n")
+	while (clgcur ("gcommands", xc, yc, wcs, key, Memc[cmd],
+	    SZ_LINE) != EOF) {
+
+	switch (key) {
+
+	    case 'q':
+	        break
+	    case '?':
+		call gpagefile (gd, HELPFILE, "")
+	    case 'f':
+	        rval = ap_cfwhmpsf (ap, gd, out, stid, rmin, rmax, imin, imax)
+	    case 's':
+	        rval = ap_csigma (ap, gd, out, stid, rmin, rmax, imin, imax)
+	    case 'l':
+	        rval = ap_cdatamin (ap, gd, out, stid, rmin, rmax, imin, imax)
+	    case 'u':
+	        rval = ap_cdatamax (ap, gd, out, stid, rmin, rmax, imin, imax)
+	    case 'c':
+	        rval = ap_ccapert (ap, gd, out, stid, rmin, rmax, imin, imax)
+	    case 'n':
+	        rval = ap_crclean (ap, gd, out, stid, rmin, rmax, imin, imax)
+	    case 'p':
+	        rval = ap_crclip (ap, gd, out, stid, rmin, rmax, imin, imax)
+	    case 'a':
+	        rval = ap_cannulus (ap, gd, out, stid, rmin, rmax, imin, imax)
+	    case 'd':
+	        rval = ap_cdannulus (ap, gd, out, stid, apstatr (ap, ANNULUS),
+		    rmin, rmax, imin, imax)
+	    case 'g':
+	        rval = ap_crgrow (ap, gd, out, stid, rmin, rmax, imin, imax)
+	    case 'r':
+		call ap_caper (ap, gd, out, stid, Memc[str], rmin, rmax,
+		    imin, imax)
+	    case 'w':
+		rval = ap_crprof (ap, gd, out, stid, rmin, rmax, imin, imax)
+	    case 'x':
+		rval = ap_crpstep (ap, gd, out, stid, rmin, rmax, imin, imax)
+	    case 'v':
+	        rval = ap_cfwhmpsf (ap, gd, out, stid, rmin, rmax, imin, imax)
+	        rval = ap_ccapert (ap, gd, out, stid, rmin, rmax, imin, imax)
+	        rval = ap_cannulus (ap, gd, out, stid, rmin, rmax, imin, imax)
+	        rval = ap_cdannulus (ap, gd, out, stid, apstatr (ap, ANNULUS),
+		    rmin, rmax, imin, imax)
+	        rval = ap_csigma (ap, gd, out, stid, rmin, rmax, imin, imax)
+		call ap_caper (ap, gd, out, stid, Memc[str], rmin, rmax,
+		    imin, imax)
+		rval = ap_crprof (ap, gd, out, stid, rmin, rmax, imin, imax)
+		rval = ap_crpstep (ap, gd, out, stid, rmin, rmax, imin, imax)
+	    default:
+		call printf ("Unknown or ambiguous keystroke command\007\n")
+	    }
+            call printf (
+         "Waiting for setup menu command (?=help, v=default setup, q=quit):\n")
+	}
+	call printf (
+	    "Interactive setup is complete. Type w to save parameters.\n")
+
+	# Restore old view port and window
+	call gsview (gd, u1, u2, v1, v2)
+	call gswind (gd, x1, x2, y1, y2)
+
+	call gdeactivate (gd, 0)
+	call sfree (sp)
+
+	# Compute the answer.
+	cier = apfitcenter (ap, im, xcenter, ycenter)
+	sier = apfitsky (ap, im, apstatr (ap, XCENTER), apstatr (ap, YCENTER),
+	    NULL, gd)
+	rier = ap_frprof (ap, im, apstatr (ap, XCENTER), apstatr (ap, YCENTER),
+	    pier)
+	call ap_rpplot (ap, 0, gd, apstati (ap, RADPLOTS))
+	call ap_qprprof (ap, cier, sier, pier, rier)
+end
diff --git a/noao/digiphot/apphot/radprof/apprprof.x b/noao/digiphot/apphot/radprof/apprprof.x
new file mode 100644
index 00000000..1d7461ee
--- /dev/null
+++ b/noao/digiphot/apphot/radprof/apprprof.x
@@ -0,0 +1,109 @@
+include "../lib/apphotdef.h"
+include "../lib/apphot.h"
+include "../lib/center.h"
+include "../lib/fitsky.h"
+include "../lib/photdef.h"
+include "../lib/phot.h"
+include "../lib/radprof.h"
+
+# AP_PRPROF -- Procedure to write the results of radprof to the output file.
+
+procedure ap_prprof (ap, fd, id, lid, cier, sier, pier, rier)
+
+pointer	ap	# pointer to apphot structure
+int	fd	# output text file descriptor
+int	id	# id number of str
+int	lid	# list id of star
+int	cier	# centering error
+int	sier	# sky fitting error
+int	pier	# photometric error
+int	rier	# radial profile error
+
+int	i, naperts
+int	apstati()
+real	apstatr()
+
+begin
+	if (fd == NULL)
+	    return
+
+	# Print the id parameters.
+	call ap_wid (ap, fd, apstatr (ap, OXINIT), apstatr (ap, OYINIT),
+	    id, lid, '\\')
+
+	# Print the center parameters.
+	call ap_wcres (ap, fd, cier, '\\')
+
+	# Print the sky values.
+	call ap_wsres (ap, fd, sier, '\\')
+
+	# Print photometry parameters.
+	naperts = apstati (ap, NAPERTS)
+	do i = 1, naperts {
+	    if (naperts == 1)
+		call ap_wmres (ap, fd, i, pier, " \\")
+	    else
+		call ap_wmres (ap, fd, i, pier, "*\\")
+	}
+
+	# Print the radprof parameters.
+	call ap_wrres (ap, fd, rier)
+end
+
+
+# AP_RPHDR -- Procedure to write the radprof banner header to the output file.
+
+procedure ap_rphdr (ap, out)
+
+pointer	ap		# apphot descriptor
+int	out		# output file descriptor
+
+begin
+	if (out == NULL)
+	    return
+
+	# Print out the keywords.
+	call ap_idhdr (ap, out)
+	call ap_chdr (ap, out)
+	call ap_shdr (ap, out)
+	call ap_mhdr (ap, out)
+	call ap_rhdr (ap, out)
+end
+
+
+# AP_QPRPROF -- Procedure to print a short version of the radprof results
+# on the standard output.
+
+procedure ap_qprprof (ap, cier, sier, pier, rier)
+
+pointer	ap	# pointer to apphot structure
+int	cier	# centering error
+int	sier	# sky fitting error
+int	pier	# phot error
+int	rier	# radprof error
+
+pointer	sp, imname, phot
+real	apstatr()
+
+begin
+	call smark (sp)
+	call salloc (imname, SZ_FNAME, TY_CHAR)
+	phot = AP_PPHOT(ap)
+
+	# Print quick summary of radprof results on the standard output.
+	call apstats (ap, IMROOT, Memc[imname], SZ_FNAME)
+	call printf ("%s  %8.2f %8.2f  %8g %5.2f  ")
+	    call pargstr (Memc[imname])
+	    call pargr (apstatr (ap, ORPXCUR))
+	    call pargr (apstatr (ap, ORPYCUR))
+	    call pargr (apstatr (ap, SKY_MODE))
+	    call pargr (apstatr (ap, RPFWHM) / apstatr (ap, SCALE))
+	call printf ("%7.3f  %s\n")
+	    call pargr (Memr[AP_MAGS(phot)+AP_NAPERTS(phot)-1])
+	if (cier != AP_OK || sier != AP_OK || pier != AP_OK || rier != AP_OK)
+	    call pargstr ("err")
+	else
+	    call pargstr ("ok")
+
+	call sfree (sp)
+end
diff --git a/noao/digiphot/apphot/radprof/apradprof.x b/noao/digiphot/apphot/radprof/apradprof.x
new file mode 100644
index 00000000..10448af2
--- /dev/null
+++ b/noao/digiphot/apphot/radprof/apradprof.x
@@ -0,0 +1,500 @@
+include <ctype.h>
+include <gset.h>
+include <imhdr.h>
+include "../lib/apphot.h"
+include "../lib/display.h"
+include "../lib/center.h"
+include "../lib/fitsky.h"
+include "../lib/radprof.h"
+
+define	HELPFILE	"apphot$radprof/radprof.key"
+
+# AP_RADPROF -- Procedure to determine radial profiles for a list of objects
+# in a list of images.
+
+int procedure ap_radprof (ap, im, cl, gd, mgd, id, out, stid, interactive,
+	cache)
+
+pointer ap			# pointer to apphot structure
+pointer	im			# pointer to IRAF image
+int	cl			# starlist file descriptor
+pointer	gd			# pointer to graphcis descriptor
+pointer	mgd			# pointer to plot metacode stream
+pointer	id			# pointer to image display stream
+int	out			# output file descriptor
+int	stid			# output file sequence number
+int	interactive		# interactive mode
+int	cache			# cache the input image pixels
+
+real	wx, wy, xlist, ylist
+pointer	sp, cmd
+int	wcs, key, oid, ltid, newlist, colonkey, req_size, buf_size, old_size
+int	newimage, newskybuf, newsky, newcenterbuf, newcenter, newbuf, newfit
+int	ip, prev_num, req_num, cier, sier, pier, rier, memstat
+
+real	apstatr()
+int	clgcur(), apfitsky(), aprefitsky(), apfitcenter(), aprefitcenter()
+int	apstati(), apgscur(), ap_frprof(), ctoi(), apgqverify(), apgtverify()
+int	apnew(), ap_avsky(), sizeof(), ap_memstat()
+bool	fp_equalr()
+
+define  endswitch_ 99
+
+begin
+	# Initialize.
+	call smark (sp)
+	call salloc (cmd, SZ_LINE, TY_CHAR)
+
+	# Initialize the cursor command.
+	key = ' '
+	Memc[cmd] = EOS
+
+	# Initialize the fit.
+	newimage = NO
+	newcenterbuf = YES; newcenter = YES
+	newskybuf = YES; newsky = YES
+	newbuf = YES; newfit = YES
+	cier = AP_OK; sier = AP_OK; pier = AP_OK; rier = AP_OK
+
+	# Initialize the sequencing.
+	newlist = NO
+	ltid = 0
+
+	# Loop over the coordinate file.
+	while (clgcur ("icommands", wx, wy, wcs, key, Memc[cmd], SZ_LINE) !=
+	    EOF) {
+
+	    # Store the cursor coords.
+	    call ap_vtol (im, wx, wy, wx, wy, 1)
+	    call apsetr (ap, CWX, wx)
+	    call apsetr (ap, CWY, wy)
+
+	    # Test to see if the cursor has moved.
+	    if (apnew (ap, wx, wy, xlist, ylist, newlist) == YES) {
+		newcenterbuf = YES; newcenter = YES
+		newskybuf = YES; newsky = YES
+		newbuf = YES; newfit = YES
+	    }
+
+	    # Switch on the keystroke commands.
+	    switch (key) {
+
+	    # Quit.
+	    case 'q':
+		if (interactive == YES) {
+		    if (apgqverify ("radprof", ap, key) == YES) {
+			call sfree (sp)
+			return (apgtverify (key))
+		    }
+	        } else {
+		    call sfree (sp)
+		    return (NO)
+	        }
+
+	    # Print the errors.
+	    case 'e':
+		if (interactive == YES)
+		    call ap_rferrors (ap, cier, sier, pier, rier)
+
+	    # Print the help page.
+	    case '?':
+		if ((id != NULL) && (id == gd))
+		    call gpagefile (id, HELPFILE, "")
+		else if (interactive == YES)
+		    call pagefile (HELPFILE, "[space=morehelp,q=quit,?=help]")
+
+	    # Rewind the list.
+	    case 'r':
+		if (cl != NULL) {
+		    call seek (cl, BOF)
+		    ltid = 0
+		} else if (interactive == YES)
+		    call printf ("No coordinate list\n")
+
+	    # Move, measure next object in the coordinate list.
+	    case 'm', 'n':
+
+		# No coordinate file.
+		if (cl == NULL) {
+                    if (interactive == YES)
+                        call printf ("No coordinate list\n")
+                    goto endswitch_
+		}
+
+		# Need to rewind the coordinate file.
+		prev_num = ltid
+		req_num = ltid + 1
+		if (apgscur (cl, id, xlist, ylist, prev_num, req_num,
+		    ltid) == EOF) {
+                    if (interactive == YES)
+                        call printf (
+                            "End of coordinate list, use r key to rewind\n")
+                    goto endswitch_
+		}
+
+		# Convert coordinates if necessary.
+                switch (apstati (ap, WCSIN)) {
+                case WCS_PHYSICAL, WCS_WORLD:
+                    call ap_itol (ap,  xlist, ylist, xlist, ylist, 1)
+                case WCS_TV:
+                    call ap_vtol (im, xlist, ylist, xlist, ylist, 1)
+                default:
+                    ;
+                }
+
+		# Move to the next object.
+		newlist = YES
+		if (key == 'm') {
+		    newcenterbuf = YES; newcenter = YES
+		    newskybuf = YES; newsky = YES
+		    newbuf = YES; newfit = YES
+                    goto endswitch_
+		}
+
+		# Measure next object.
+		cier = apfitcenter (ap, im, xlist, ylist)
+		sier = apfitsky (ap, im, apstatr (ap, XCENTER), apstatr (ap,
+		    YCENTER), NULL, gd)
+		rier = ap_frprof (ap, im, apstatr (ap, XCENTER), apstatr (ap,
+		    YCENTER), pier)
+		call aprmark (ap, id, apstati (ap, MKCENTER), apstati (ap,
+		    MKSKY), apstati (ap, MKAPERT))
+	        if (id != NULL) {
+		    if (id == gd)
+		    	call gflush (id)
+		    else
+		        call gframe (id)
+		}
+	        call ap_rpplot (ap, stid, gd, apstati (ap, RADPLOTS))
+		if (interactive == YES)
+		    call ap_qprprof (ap, cier, sier, pier, rier)
+		if (stid == 1)
+		    call ap_param (ap, out, "radprof")
+		call ap_prprof (ap, out, stid, ltid, cier, sier, pier, rier)
+		call ap_rpplot (ap, stid, mgd, YES)
+		stid = stid + 1
+		newcenterbuf = NO; newcenter = NO
+		newskybuf = NO; newsky = NO
+		newbuf = NO; newfit = NO
+
+	    # Process the remainder of the list.
+	    case 'l':
+		if (cl != NULL) {
+		    oid = stid
+		    ltid = ltid + 1
+		    call ap_bradprof (ap, im, cl, id, gd, mgd, out, stid, ltid,
+		        YES)
+		    ltid = ltid + stid - oid + 1
+		    if (id != NULL) {
+			if (id == gd)
+			    call gflush (id)
+			else
+			    call gframe (id)
+		    }
+		} else if (interactive == YES)
+		    call printf ("No coordinate list\n")
+
+	    # Process radprof colon commands.
+	    case ':':
+		for (ip = 1; IS_WHITE(Memc[cmd+ip-1]); ip = ip + 1)
+		    ;
+		colonkey = Memc[cmd+ip-1]
+		switch (colonkey) {
+		case 'm', 'n':
+
+		    # Show/set radprof parameters.
+		    if (Memc[cmd+ip] != EOS && Memc[cmd+ip] != ' ') {
+		        call ap_rpcolon (ap, im, cl, out, stid, ltid, Memc[cmd],
+			    newimage, newcenterbuf, newcenter, newskybuf,
+			    newsky, newbuf, newfit)
+			goto endswitch_
+		    }
+
+		    # Process the next object.
+		    if (cl == NULL) {
+                        if (interactive == YES)
+                            call printf ("No coordinate list\n")
+                        goto endswitch_
+		    }
+
+		    # Get next object from the list.
+		    ip = ip + 1
+		    prev_num = ltid
+		    if (ctoi (Memc[cmd], ip, req_num) <= 0)
+		        req_num = ltid + 1
+
+		    # Fetch next object from the list.
+		    if (apgscur (cl, id, xlist, ylist, prev_num, req_num,
+			ltid) == EOF) {
+                        if (interactive == YES)
+                            call printf (
+                            "End of coordinate list, use r key to rewind\n")
+                        goto endswitch_
+
+		    }
+
+                    # Convert the coordinates.
+                    switch (apstati (ap, WCSIN)) {
+                    case WCS_PHYSICAL, WCS_WORLD:
+                        call ap_itol (ap,  xlist, ylist, xlist, ylist, 1)
+                    case WCS_TV:
+                        call ap_vtol (im, xlist, ylist, xlist, ylist, 1)
+                    default:
+                        ;
+                    }
+
+		    # Move to next object.
+		    newlist = YES
+		    if (colonkey == 'm') {
+		        newcenterbuf = YES; newcenter = YES
+		        newskybuf = YES; newsky = YES
+		        newbuf = YES; newfit = YES
+		    }
+
+		    # Measure the next object.
+		    cier = apfitcenter (ap, im, xlist, ylist)
+		    sier = apfitsky (ap, im, apstatr (ap, XCENTER),
+			apstatr (ap, YCENTER), NULL, gd)
+		    rier = ap_frprof (ap, im, apstatr (ap, XCENTER),
+			apstatr (ap, YCENTER), pier)
+		    call aprmark (ap, id, apstati (ap, MKCENTER), apstati (ap,
+			MKSKY), apstati (ap, MKAPERT))
+		    if (id != NULL) {
+		        if (id == gd)
+		    	    call gflush (id)
+			else
+			    call gframe (id)
+		    }
+		    call ap_rpplot (ap, stid, gd, apstati (ap, RADPLOTS))
+		    if (interactive == YES)
+		        call ap_qprprof (ap, cier, sier, pier, rier)
+
+		    if (stid == 1)
+		        call ap_param (ap, out, "radprof")
+		    call ap_prprof (ap, out, stid, ltid, cier, sier, pier, rier)
+		    call ap_rpplot (ap, stid, mgd, YES)
+		    stid = stid + 1
+		     newcenterbuf = NO; newcenter = NO
+		     newskybuf = NO; newsky = NO
+		     newbuf = NO; newfit = NO
+
+		default:
+		    call ap_rpcolon (ap, im, cl, out, stid, ltid, Memc[cmd],
+		        newimage, newcenterbuf, newcenter, newskybuf, newsky,
+			newbuf, newfit)
+		}
+
+		# Reestablish the image viewport and window.
+		if (newimage == YES) {
+		    if ((id != NULL) && (id != gd))
+		        call ap_gswv (id, Memc[cmd], im, 4)
+                    req_size = MEMFUDGE * IM_LEN(im,1) * IM_LEN(im,2) *
+                        sizeof (IM_PIXTYPE(im))
+                    memstat = ap_memstat (cache, req_size, old_size)
+                    if (memstat == YES)
+                        call ap_pcache (im, INDEFI, buf_size)
+		}
+
+		newimage = NO
+
+	    # Save the parameters.
+	    case 'w':
+		call ap_rpars (ap)
+
+	    # Plot a simple centered radial profile.
+	    case 'd':
+		if (interactive == YES) {
+		    call ap_qrad (ap, im, wx, wy, gd)
+		    newcenterbuf = YES; newcenter = YES
+		    newskybuf = YES; newsky = YES
+		    newbuf = YES; newfit = YES
+		}
+		
+
+	    # Setup the radial profile fitting parameters interactively.
+	    case 'i':
+		if (interactive == YES) {
+		    call ap_profsetup (ap, im, wx, wy, gd, out, stid)
+		    newcenterbuf = YES; newcenter = YES
+		    newskybuf = YES; newsky = YES
+		    newbuf = YES; newfit = YES
+		}
+
+	    # Verify the critical radprof parameters.
+	    case 'v':
+		call ap_rconfirm (ap, out, stid)
+		newcenterbuf = YES; newcenter = YES
+		newskybuf = YES; newsky = YES
+		newbuf = YES; newfit = YES
+
+	     # Fit the center around the current cursor value.
+	     case 'c':
+		if (newcenterbuf == YES)
+		    cier = apfitcenter (ap, im, wx, wy)
+		else if (newcenter == YES)
+		    cier = aprefitcenter (ap, im, cier)
+		call aprmark (ap, id, apstati (ap, MKCENTER), NO, NO)
+		if (id != NULL) {
+		    if (id == gd)
+			call gflush (id)
+		    else
+			call gframe (id)
+		}
+		call ap_cplot (ap, stid, gd, apstati (ap, RADPLOTS))
+		if (interactive == YES)
+		    call ap_qcenter (ap, cier)
+		newcenterbuf = NO; newcenter = NO
+
+	    # Fit the sky around the current cursor value.
+	    case 't':
+	        if (newskybuf == YES || ! fp_equalr (wx,
+		    apstatr (ap, SXCUR)) || ! fp_equalr (wy, apstatr (ap,
+		    SYCUR)))
+		    sier = apfitsky (ap, im, wx, wy, NULL, gd)
+	        else if (newsky == YES)
+		    sier = aprefitsky (ap, im, gd)
+		call aprmark (ap, id, NO, apstati (ap, MKSKY), NO)
+		if (id != NULL) {
+		    if (id == gd)
+			call gflush (id)
+		    else
+			call gframe (id)
+		}
+		call ap_splot (ap, stid, gd, apstati (ap, RADPLOTS))
+		if (interactive == YES)
+		    call ap_qspsky (ap, sier)
+		newskybuf = NO; newsky = NO
+
+	    # Compute the average of several sky measurements around
+            # different cursor postions.
+            case 'a':
+                sier = ap_avsky (ap, im, stid, NULL, id, gd, interactive)
+                if (interactive == YES)
+                    call ap_qaspsky (ap, sier)
+                newskybuf = NO; newsky = NO
+
+	     # Fit the sky around derived center value. 
+	     case 's':
+	        if (newskybuf == YES || ! fp_equalr (apstatr (ap, XCENTER),
+		    apstatr (ap, SXCUR)) || ! fp_equalr (apstatr (ap,
+		    SYCUR), apstatr (ap, YCENTER)))
+		    sier = apfitsky (ap, im, apstatr (ap, XCENTER),
+		        apstatr (ap, YCENTER), NULL, gd)
+		else if (newsky == YES)
+		    sier = aprefitsky (ap, im, gd)
+		call aprmark (ap, id, NO, apstati (ap, MKSKY), NO)
+		if (id != NULL) {
+		    if (id == gd)
+			call gflush (id)
+		    else
+			call gframe (id)
+		}
+		call ap_splot (ap, stid, gd, apstati (ap, RADPLOTS))
+		if (interactive == YES)
+		    call ap_qspsky (ap, sier)
+		newskybuf = NO; newsky = NO
+
+	    # Compute magnitudes around the current cursor position using
+	    # the current sky.
+	    case 'p', 'o':
+		if (newcenterbuf == YES)
+		    cier = apfitcenter (ap, im, wx, wy)
+		else if (newcenter == YES)
+		    cier = aprefitcenter (ap, im, cier)
+		call aprmark (ap, id, apstati (ap, MKCENTER), NO,
+		    apstati (ap, MKAPERT))
+		if (id != NULL) {
+		    if (id == gd)
+			call gflush (id)
+		    else
+			call gframe (id)
+		}
+	        if (newfit == YES || newbuf == YES || ! fp_equalr (apstatr (ap,
+		    XCENTER), apstatr (ap, RPXCUR)) ||
+		    ! fp_equalr (apstatr (ap, RPYCUR), apstatr (ap, YCENTER)))
+		    rier = ap_frprof (ap, im, apstatr (ap, XCENTER),
+		        apstatr (ap, YCENTER), pier)
+		if (interactive == YES)
+		    call ap_qprprof (ap, cier, sier, pier, rier)
+		newcenterbuf = NO; newcenter = NO
+		newbuf = NO; newfit = NO
+
+		if (key == 'o') {
+		    if (stid == 1)
+		        call ap_param (ap, out, "radprof")
+		    if (newlist == YES)
+		        call ap_prprof (ap, out, stid, ltid, cier, sier, pier,
+			    rier)
+		    else
+		        call ap_prprof (ap, out, stid, 0, cier, sier, pier,
+			    rier)
+		    call ap_rpplot (ap, stid, mgd, YES)
+		    stid = stid + 1
+		}
+
+	    # Center, fit the sky, and compute magnitudes.
+	    # Compute the centers, fit the sky, compute the magnitudes
+	    # and save the results.
+	    case 'f', ' ':
+		if (newcenterbuf == YES)
+		    cier = apfitcenter (ap, im, wx, wy)
+		else if (newcenter == YES)
+		    cier = aprefitcenter (ap, im, cier)
+		if (newskybuf == YES || ! fp_equalr (apstatr (ap, XCENTER),
+		    apstatr (ap, SXCUR)) || ! fp_equalr (apstatr (ap, YCENTER),
+		    apstatr (ap, SYCUR)))
+		    sier = apfitsky (ap, im, apstatr (ap, XCENTER),
+		        apstatr (ap, YCENTER), NULL, gd)
+		else if (newsky == YES)
+		    sier = aprefitsky (ap, im, gd)
+
+		if (newfit == YES || newbuf == YES || ! fp_equalr (apstatr (ap,
+		    XCENTER), apstatr (ap, RPXCUR)) || ! fp_equalr (apstatr (ap,
+		    YCENTER), apstatr (ap, RPYCUR)))
+		    rier = ap_frprof (ap, im, apstatr (ap, XCENTER),
+		        apstatr (ap, YCENTER), pier)
+		call aprmark (ap, id, apstati (ap, MKCENTER), apstati (ap,
+		    MKSKY), apstati (ap, MKAPERT))
+		if (id != NULL) {
+		    if (id == gd)
+			call gflush (id)
+		    else
+			call gframe (id)
+		}
+		call ap_rpplot (ap, stid, gd, apstati (ap, RADPLOTS))
+		if (interactive == YES)
+		    call ap_qprprof (ap, cier, sier, pier, rier)
+
+		newcenterbuf = NO; newcenter = NO
+		newskybuf = NO; newsky = NO
+		newbuf = NO; newfit = NO
+
+		if (key == ' ') {
+		    if (stid == 1)
+		        call ap_param (ap, out, "radprof")
+		    if (newlist == YES)
+		        call ap_prprof (ap, out, stid, ltid, cier, sier, pier,
+			    rier)
+		    else
+		        call ap_prprof (ap, out, stid, 0, cier, sier, pier,
+			    rier)
+		    call ap_rpplot (ap, stid, mgd, YES)
+		    stid = stid + 1
+		}
+
+	    default:
+		# do nothing
+		call printf ("Print unknown or ambiguous colon command\n")
+	    }
+
+endswitch_
+	    # Prepare for the next object.
+	    key = ' '
+	    Memc[cmd] = EOS
+	    call apsetr (ap, WX, apstatr (ap, CWX))
+	    call apsetr (ap, WY, apstatr (ap, CWY))
+
+	}
+
+	call sfree (sp)
+end
diff --git a/noao/digiphot/apphot/radprof/aprconfirm.x b/noao/digiphot/apphot/radprof/aprconfirm.x
new file mode 100644
index 00000000..3c775e79
--- /dev/null
+++ b/noao/digiphot/apphot/radprof/aprconfirm.x
@@ -0,0 +1,118 @@
+include "../lib/apphot.h"
+include "../lib/noise.h"
+include "../lib/center.h"
+include "../lib/fitsky.h"
+include "../lib/phot.h"
+include "../lib/radprof.h"
+
+# AP_RCONFIRM -- Procedure to confirm the critical phot parameters.
+
+procedure ap_rconfirm (ap, out, stid)
+
+pointer	ap		# pointer to the apphot structure
+int	out		# output file descriptor
+int	stid		# output file sequence number
+
+pointer	sp, cstr, sstr, aperts
+real	fwhmpsf, capert, annulus, dannulus, skysigma
+real	datamin, datamax, radius, step
+int	apstati()
+real	apstatr(), ap_vfwhmpsf(), ap_vcapert()
+real	ap_vannulus(), ap_vdannulus(), ap_vsigma(), ap_vstep()
+real	ap_vdatamin(), ap_vdatamax(), ap_vrpradius()
+
+begin
+	call smark (sp)
+	call salloc (cstr, SZ_FNAME, TY_CHAR)
+	call salloc (sstr, SZ_FNAME, TY_CHAR)
+	call salloc (aperts, SZ_LINE, TY_CHAR)
+
+	call printf ("\n")
+
+	# Confirm the centering algorithm.
+	call ap_vcstring (ap, Memc[cstr], SZ_FNAME)
+
+	if (apstati (ap, CENTERFUNCTION) != AP_NONE) {
+
+	    # Confirm the fwhmpsf.
+	    if (apstati (ap, CENTERFUNCTION) != AP_CENTROID1D)
+		fwhmpsf = ap_vfwhmpsf (ap)
+	    else
+		fwhmpsf = apstatr (ap, FWHMPSF)
+
+	    # Confirm the centering box.
+	    capert = 2.0 * ap_vcapert (ap)
+
+	} else {
+	    fwhmpsf = apstatr (ap, FWHMPSF)
+	    capert = 2.0 * apstatr (ap, CAPERT)
+	}
+
+	# Confirm the sky fitting algorithm.
+	call ap_vsstring (ap, Memc[sstr], SZ_FNAME)
+
+	if (apstati (ap, SKYFUNCTION) != AP_CONSTANT &&
+	    apstati (ap, SKYFUNCTION) != AP_SKYFILE) {
+
+	    # Confirm the sky annulus parameter.
+	    annulus = ap_vannulus (ap)
+
+	    # Confirm the width of the sky annulus.
+	    dannulus = ap_vdannulus (ap)
+
+	} else {
+	    annulus = apstatr (ap, ANNULUS)
+	    dannulus = apstatr (ap, DANNULUS)
+	}
+
+	# Confirm the sky sigma parameter.
+	if (apstati (ap, SKYFUNCTION) != AP_SKYFILE)
+	    skysigma = ap_vsigma (ap)
+	else
+	    skysigma = apstatr (ap, SKYSIGMA)
+
+	# Confirm the aperture radii parameter.
+	call ap_vaperts (ap, Memc[aperts], SZ_LINE)
+
+	# Confirm the radius of profile
+	radius = ap_vrpradius (ap)
+
+	# Confirm the step size of profile
+	step = ap_vstep (ap)
+
+	# Confirm the minimum and maximum good data values.
+	datamin = ap_vdatamin (ap)
+	datamax = ap_vdatamax (ap)
+
+	call printf ("\n")
+
+	# Update the database file.
+	if (out != NULL && stid > 1) {
+	    call ap_sparam (out, KY_CSTRING, Memc[cstr], UN_CALGORITHM,
+		"centering algorithm")
+	    call ap_rparam (out, KY_FWHMPSF, fwhmpsf, UN_ASCALEUNIT,
+	        "full width half maximum of the psf")
+	    call ap_rparam (out, KY_CAPERT, capert, UN_CSCALEUNIT,
+	        "centering box width")
+	    call ap_sparam (out, KY_SSTRING, Memc[sstr], UN_SALGORITHM,
+		"sky fitting algorithm")
+	    call ap_rparam (out, KY_ANNULUS, annulus, UN_SSCALEUNIT,
+	        "inner radius of the sky annulus")
+	    call ap_rparam (out, KY_DANNULUS, dannulus, UN_SSCALEUNIT,
+	        "width of the sky annulus")
+	    call ap_rparam (out, KY_SKYSIGMA, skysigma, UN_NCOUNTS,
+	        "standard deviation of 1 sky pixel")
+	    call ap_sparam (out, KY_APERTS, Memc[aperts], UN_PSCALEUNIT,
+		"list of apertures")
+	    call ap_rparam (out, KY_DATAMIN, datamin, UN_ACOUNTS,
+	        "minimum good data value")
+	    call ap_rparam (out, KY_DATAMAX, datamax, UN_ACOUNTS,
+	        "maximum good data value")
+	    call ap_rparam (out, KY_RPRADIUS, radius, UN_RSCALEUNIT,
+	        "fitting radius")
+	    call ap_rparam (out, KY_RPSTEP, step, UN_RSCALEUNIT,
+	        "step size in radius")
+	}
+
+	call sfree (sp)
+end
diff --git a/noao/digiphot/apphot/radprof/aprferrors.x b/noao/digiphot/apphot/radprof/aprferrors.x
new file mode 100644
index 00000000..f72586f3
--- /dev/null
+++ b/noao/digiphot/apphot/radprof/aprferrors.x
@@ -0,0 +1,40 @@
+include "../lib/phot.h"
+include "../lib/radprof.h"
+
+# AP_RFERRORS -- Procedure to print a short form of the output of radprof on
+# the standard output.
+
+procedure ap_rferrors (ap, cier, sier, pier, rier)
+
+pointer	ap	# pointer to apphot structure
+int	cier	# centering error
+int	sier	# sky fitting error
+int	pier	# photmetry error
+int	rier	# photometric error
+
+begin
+	# Print the centering errors.
+	call ap_cerrors (ap, cier)
+
+	# Print the sky fitting errors.
+	call ap_serrors (ap, sier)
+
+	# Print the photometry errors.
+	call ap_merrors (ap, pier)
+
+	# Print the radial profile fitting errors.
+	switch (rier) {
+	case AP_RP_NOPROFILE:
+	    call printf ("The profile fitting region is outside the image.\n")
+	case AP_RP_OUTOFBOUNDS:
+	    call printf (
+	        "The profile fitting region is partially outside the image.\n")
+	case AP_RP_NPTS_TOO_SMALL:
+	    call printf (
+	        "There are too few points in the profile fitting region.\n")
+	case AP_RP_SINGULAR:
+	    call printf ("The profile fit is singular.\n")
+	default:
+	    call printf ("")
+	}
+end
diff --git a/noao/digiphot/apphot/radprof/aprmmeasure.x b/noao/digiphot/apphot/radprof/aprmmeasure.x
new file mode 100644
index 00000000..fe455008
--- /dev/null
+++ b/noao/digiphot/apphot/radprof/aprmmeasure.x
@@ -0,0 +1,96 @@
+include <math/curfit.h>
+
+# AP_RMMEASURE -- Procedure to compute the sums and areas inside the apertures.
+
+procedure ap_rmmeasure (pixels, nx, ny, wx, wy, aperts, sums, areas, naperts)
+
+real	pixels[nx,ARB]		# subraster pixel values
+int	nx, ny			# dimensions of the subraster
+real	wx, wy			# center of subraster
+real	aperts[ARB]		# array of apertures
+double	sums[ARB]		# array of sums
+double	areas[ARB]		# aperture areas
+int	naperts			# number of apertures
+
+int	i, j, k
+double	fctn
+real	apmaxsq, dy2, r2, r
+
+begin
+	# Initialize.
+	apmaxsq = (aperts[naperts] + 0.5) ** 2
+	call aclrd (sums, naperts)
+	call aclrd (areas, naperts)
+
+	# Loop over the pixels.
+	do j = 1, ny {
+	    dy2 = (j - wy) ** 2
+	    do i = 1, nx {
+		r2 = (i - wx) ** 2 + dy2
+		if (r2 > apmaxsq)
+		    next
+		r = sqrt (r2) - 0.5
+		do k = 1, naperts {
+		    if (r > aperts[k])
+			next
+		    fctn = max (0.0, min (1.0, aperts[k] - r))
+		    sums[k] = sums[k] + fctn * pixels[i,j]
+		    areas[k] = areas[k] + fctn
+		}
+	    }
+	}
+end
+
+
+# AP_BRMMEASURE -- Procedure to compute the sums and areas inside the apertures.
+
+procedure ap_brmmeasure (pixels, nx, ny, wx, wy, datamin, datamax, aperts,
+	sums, areas, naperts, minapert)
+
+real	pixels[nx,ARB]		# subraster pixel values
+int	nx, ny			# dimensions of the subraster
+real	wx, wy			# center of subraster
+real	datamin			# minimum good data value
+real	datamax			# maximum good data value
+real	aperts[ARB]		# array of apertures
+double	sums[ARB]		# array of sums
+double	areas[ARB]		# aperture areas
+int	naperts			# number of apertures
+int	minapert		# minimum number of apertures
+
+int	i, j, k, kindex
+double	fctn
+real	apmaxsq, dy2, r2, r, pixval
+
+begin
+	# Initialize.
+	apmaxsq = (aperts[naperts] + 0.5) ** 2
+	call aclrd (sums, naperts)
+	call aclrd (areas, naperts)
+	minapert = naperts + 1
+
+	# Loop over the pixels.
+	do j = 1, ny {
+	    dy2 = (j - wy) ** 2
+	    do i = 1, nx {
+		r2 = (i - wx) ** 2 + dy2
+		if (r2 > apmaxsq)
+		    next
+		r = sqrt (r2) - 0.5
+		kindex = naperts + 1
+		pixval = pixels[i,j]
+		do k = 1, naperts {
+		    if (r > aperts[k])
+			next
+		    kindex = min (k, kindex)
+		    fctn = max (0.0, min (1.0, aperts[k] - r))
+		    sums[k] = sums[k] + fctn * pixval
+		    areas[k] = areas[k] + fctn
+		}
+		if (kindex < minapert) {
+		    if (pixval < datamin || pixval > datamax)
+			minapert = kindex
+		}
+	    }
+	}
+end
diff --git a/noao/digiphot/apphot/radprof/aprpars.x b/noao/digiphot/apphot/radprof/aprpars.x
new file mode 100644
index 00000000..fb4ed401
--- /dev/null
+++ b/noao/digiphot/apphot/radprof/aprpars.x
@@ -0,0 +1,37 @@
+include "../lib/display.h"
+include "../lib/radprof.h"
+
+# AP_RPARS -- Procedure to write the radprof parameters to the parameter
+# file.
+
+procedure ap_rpars (ap)
+
+pointer	ap		# pointer to apphot structure
+
+bool	itob()
+int	apstati()
+real	apstatr()
+
+begin
+	# Write the data dependent parameters.
+	call ap_dapars (ap)
+
+	# Write the centering parameters.
+	call ap_cepars (ap)
+
+	# Write the sky fitting parameters.
+	call ap_sapars (ap)
+
+	# Write out the photometry parameters.
+	call ap_phpars (ap)
+
+	# Set the radphot parameters
+	call clputr ("radius", apstatr (ap, RPRADIUS))
+	call clputr ("step", apstatr (ap, RPSTEP))
+	call clputi ("order", apstati (ap, RPORDER))
+	call clputr ("kreject", apstatr (ap, RPKSIGMA))
+	call clputi ("nreject", apstati (ap, RPNREJECT))
+
+	# Set radial profile plots
+	call clputb ("radplots", itob (apstati (ap, RADPLOTS)))
+end
diff --git a/noao/digiphot/apphot/radprof/aprpbuf.x b/noao/digiphot/apphot/radprof/aprpbuf.x
new file mode 100644
index 00000000..3a2f73ed
--- /dev/null
+++ b/noao/digiphot/apphot/radprof/aprpbuf.x
@@ -0,0 +1,82 @@
+include <imhdr.h>
+include "../lib/apphotdef.h"
+include "../lib/radprofdef.h"
+include "../lib/radprof.h"
+
+# AP_RPBUF -- Procedure to determine the mapping of the of the radial
+# profile size into the apertures.
+
+int procedure ap_rpbuf (ap, im, wx, wy)
+
+pointer	ap		# pointer to apphot structure
+pointer	im		# pointer to the IRAF image
+real	wx, wy		# center coordinates
+
+int	c1, c2, l1, l2
+pointer	rprof
+real	rbuf
+pointer ap_rppix()
+
+begin
+	# Check for 0 radius aperture.
+	rprof = AP_RPROF(ap)
+	if (AP_RPRADIUS(rprof) <= 0.0)
+	    return (AP_RP_NOPROFILE)
+
+	# Compute the maximum aperture size
+	rbuf =  2. * AP_RPRADIUS(rprof) * AP_SCALE(ap) + 1.
+	AP_RPIX(rprof) = ap_rppix (im, wx, wy, rbuf, c1, c2, l1, l2)
+	AP_RPXC(rprof) = wx - c1 + 1 
+	AP_RPYC(rprof) = wy - l1 + 1
+	AP_RPNX(rprof) = c2 - c1 + 1
+	AP_RPNY(rprof) = l2 - l1 + 1
+
+	# Return the appropriate error code.
+	if (AP_RPIX(rprof) == NULL) {
+	    return (AP_RP_NOPROFILE)
+	} else if (AP_RPNX(rprof) < rbuf || AP_RPNY(rprof) < rbuf) {
+	    return (AP_RP_OUTOFBOUNDS)
+	} else {
+	    return (AP_OK)
+	}
+end
+
+
+# AP_RPPIX -- Procedure to read in the aperture pixels
+
+pointer procedure ap_rppix (im, wx, wy, papert, c1, c2, l1, l2)
+
+pointer	im		# pointer to IRAF image
+real	wx, wy		# center of centering subraster annulus
+real	papert		# centering radius
+int	c1, c2		# column limits
+int	l1, l2		# line limits
+
+int	ncols, nlines
+real	half_papert, xc1, xc2, xl1, xl2
+pointer	imgs2r()
+
+begin
+	# Check for 0 radius aperture.
+	half_papert = papert / 2.
+	if (half_papert <= 0.)
+	    return (NULL)
+	ncols = IM_LEN(im,1)
+	nlines = IM_LEN(im,2)
+
+	# Test for an out of bounds aperture.
+	xc1 = wx - half_papert
+	xc2 = wx + half_papert
+	xl1 = wy - half_papert
+	xl2 = wy + half_papert
+	if (xc1 > real (ncols) || xc2 < 1.0 || xl1 > real (nlines) || xl2 < 1.0)
+	    return (NULL)
+
+	# Get the column and line limits, dimensions and center of the subraster
+	# to be extracted.
+	c1 = max (1.0, min (real (ncols), xc1))
+	c2 = min (real (ncols), max (1.0, xc2))
+	l1 = max (1.0, min (real (nlines), xl1))
+	l2 = min (real (nlines), max (1.0, xl2))
+	return (imgs2r (im, c1, c2, l1, l2))
+end
diff --git a/noao/digiphot/apphot/radprof/aprpcolon.x b/noao/digiphot/apphot/radprof/aprpcolon.x
new file mode 100644
index 00000000..a5bf0eab
--- /dev/null
+++ b/noao/digiphot/apphot/radprof/aprpcolon.x
@@ -0,0 +1,241 @@
+include "../lib/apphot.h"
+include "../lib/noise.h"
+include "../lib/center.h"
+include "../lib/fitsky.h"
+include "../lib/phot.h"
+include "../lib/radprof.h"
+include "../lib/display.h"
+
+# AP_RPCOLON -- Show/set radprof parameters.
+
+procedure ap_rpcolon (ap, im, cl, out, stid, ltid, cmdstr, newimage,
+    newcenterbuf, newcenter, newskybuf, newsky, newbuf, newfit)
+
+pointer	ap				# pointer to the apphot structure
+pointer	im				# pointer to iraf image
+int	cl				# coord file descriptor
+int	out				# output file descriptor
+int	stid				# output file sequence number
+int	ltid				# coord list sequence number
+char	cmdstr[ARB]			# command string
+int	newimage			# new image 
+int	newcenterbuf, newcenter		# new sky fit
+int	newskybuf, newsky		# new sky buffer
+int	newbuf, newfit			# new aperture
+
+pointer	sp, incmd, outcmd
+int	strdic()
+
+begin
+	call smark (sp)
+	call salloc (incmd, SZ_LINE, TY_CHAR)
+	call salloc (outcmd, SZ_LINE, TY_CHAR)
+
+	# Get the commands.
+	call sscan (cmdstr)
+	call gargwrd (Memc[incmd], SZ_LINE)
+	if (Memc[incmd] == EOS) {
+	    call sfree (sp)
+	    return
+	}
+
+	# Process the command.
+	if (strdic (Memc[incmd], Memc[outcmd], SZ_LINE, CCMDS) != 0)
+	    call apccolon (ap, out, stid, cmdstr, newcenterbuf, newcenter)
+	else if (strdic (Memc[incmd], Memc[outcmd], SZ_LINE, SCMDS) != 0)
+	    call apscolon (ap, out, stid, cmdstr, newskybuf, newsky)
+	else if (strdic (Memc[incmd], Memc[outcmd], SZ_LINE, RPCMDS) != 0)
+	    call ap_profcolon (ap, out, stid, cmdstr, newbuf, newfit)
+	else if (strdic (Memc[incmd], Memc[outcmd], SZ_LINE, PCMDS) != 0)
+	    call apmagcolon (ap, out, stid, cmdstr, newbuf, newfit)
+	else if (strdic (Memc[incmd], Memc[outcmd], SZ_LINE, APCMDS) != 0)
+	    call ap_apcolon (ap, im, cl, out, stid, ltid, cmdstr, newimage,
+	        newcenterbuf, newcenter, newskybuf, newsky, newbuf, newfit)
+	else if (strdic (Memc[incmd], Memc[outcmd], SZ_LINE, NCMDS) != 0)
+	    call ap_nscolon (ap, im, out, stid, cmdstr, newcenterbuf,
+	        newcenter, newskybuf, newsky, newbuf, newfit)
+	else
+	    call ap_rpimcolon (ap, cmdstr)
+
+	call sfree (sp)
+end
+
+
+# AP_PROFCOLON -- Procedure to display and modify radprof parameters.
+
+procedure ap_profcolon (ap, out, stid, cmdstr, newbuf, newfit)
+
+pointer	ap		# pointer to apphot structure
+int	out		# output file descriptor
+int	stid		# output file number
+char	cmdstr[ARB]	# command string
+int	newbuf		# new aperture buffers
+int	newfit		# compute new magnitudes
+
+int	ival, ncmd
+pointer	sp, cmd
+real	rval
+int	strdic(), nscan(), apstati()
+real	apstatr()
+
+begin
+	# Get the command.
+	call smark (sp)
+	call salloc (cmd, SZ_LINE, TY_CHAR)
+
+	call sscan (cmdstr)
+	call gargwrd (Memc[cmd], SZ_LINE)
+	if (Memc[cmd] == EOS) {
+	    call sfree (sp)
+	    return
+	}
+
+	# Process the colon command.
+	ncmd = strdic (Memc[cmd], Memc[cmd], SZ_LINE, RPCMDS)
+	switch (ncmd) {
+	case RCMD_RADIUS:
+	    call gargr (rval)
+	    if (nscan() == 1) {
+		call printf ("%s = %g %s\n")
+		    call pargstr (KY_RPRADIUS)
+		    call pargr (apstatr (ap, RPRADIUS))
+		    call pargstr (UN_RSCALEUNIT)
+	    } else {
+		call apsetr (ap, RPRADIUS, rval)
+		if (stid > 1)
+		    call ap_rparam (out, KY_RPRADIUS, rval, UN_RSCALEUNIT,
+			"fitting radius")
+		newbuf = YES; newfit = YES
+	    }
+	case RCMD_STEPSIZE:
+	    call gargr (rval)
+	    if (nscan() == 1) {
+		call printf ("%s = %g %s\n")
+		    call pargstr (KY_RPSTEP)
+		    call pargr (apstatr (ap, RPSTEP))
+		    call pargstr (UN_RSCALEUNIT)
+	    } else {
+		call apsetr (ap, RPSTEP, rval)
+		if (stid > 1)
+		    call ap_rparam (out, KY_RPSTEP, rval, UN_RSCALEUNIT,
+			"step size in radius")
+		newfit = YES
+	    }
+	case RCMD_ORDER:
+	    call gargi (ival)
+	    if (nscan() == 1) {
+		call printf ("%s = %d\n")
+		    call pargstr (KY_RPORDER)
+		    call pargi (apstati (ap, RPORDER))
+	    } else {
+		call apseti (ap, RPORDER, ival)
+		if (stid > 1)
+		    call ap_iparam (out, KY_RPORDER, ival, UN_RNUMBER,
+			"maximum number of rejection cycels")
+		newfit = YES
+	    }
+	case RCMD_KREJECT:
+	    call gargr (rval)
+	    if (nscan() == 1) {
+		call printf ("%s = %g %s\n")
+		    call pargstr (KY_RPKSIGMA)
+		    call pargr (apstatr (ap, RPKSIGMA))
+		    call pargstr (UN_RSIGMA)
+	    } else {
+		call apsetr (ap, RPKSIGMA, rval)
+		if (stid > 1)
+		    call ap_rparam (out, KY_RPKSIGMA, rval, UN_RSIGMA,
+			"k-sigma rejection criteron")
+		newfit = YES
+	    }
+	case RCMD_NREJECT:
+	    call gargi (ival)
+	    if (nscan() == 1) {
+		call printf ("%s = %d\n")
+		    call pargstr (KY_RPNREJECT)
+		    call pargi (apstati (ap, RPNREJECT))
+	    } else {
+		call apseti (ap, RPNREJECT, ival)
+		if (stid > 1)
+		    call ap_iparam (out, KY_RPNREJECT, ival, UN_RNUMBER,
+			"maximum number of rejection cycles")
+		newfit = YES
+	    }
+	default:
+	    call printf ("Unknown or ambiguous colon command\7\n")
+	}
+	call sfree (sp)
+end
+
+
+# AP_RPIMCOLON -- Show/set quantities which are not radprof parameters.
+
+procedure ap_rpimcolon (ap, cmdstr)
+
+pointer	ap			# pointer to the apphot structure
+char	cmdstr[ARB]		# command string
+
+bool	bval
+int	ncmd
+pointer	sp, cmd
+bool	itob()
+int	apstati(), strdic(), nscan(), btoi()
+
+begin
+	call smark (sp)
+	call salloc (cmd, SZ_LINE, TY_CHAR)
+
+	# Get the command.
+	call sscan (cmdstr)
+	call gargwrd (Memc[cmd], SZ_LINE)
+	if (Memc[cmd] == EOS) {
+	    call sfree (sp)
+	    return
+	}
+
+	# Process the command.
+	ncmd = strdic (Memc[cmd], Memc[cmd], SZ_LINE, MISC)
+	switch (ncmd) {
+	case ACMD_SHOW:
+	    call gargwrd (Memc[cmd], SZ_LINE)
+	    ncmd = strdic (Memc[cmd], Memc[cmd], SZ_LINE, RPSHOWARGS)
+	    switch (ncmd) {
+	    case RCMD_CENTER:
+		call printf ("\n")
+		call ap_cpshow (ap)
+		call printf ("\n")
+	    case RCMD_SKY:
+		call printf ("\n")
+		call ap_spshow (ap)
+		call printf ("\n")
+	    case RCMD_PHOT:
+		call printf ("\n")
+		call ap_mpshow (ap)
+		call printf ("\n")
+	    case RCMD_FIT:
+		call printf ("\n")
+		call ap_rppshow (ap)
+		call printf ("\n")
+	    case RCMD_DATA:
+		call printf ("\n")
+		call ap_nshow (ap)
+		call printf ("\n")
+	    default:
+		call printf ("\n")
+		call ap_rprofshow (ap)
+		call printf ("\n")
+	    }
+	case ACMD_RADPLOTS:
+	    call gargb (bval)
+	    if (nscan() == 1) {
+		call printf ("%s = %b\n")
+		    call pargstr (KY_RADPLOTS)
+		    call pargb (itob (apstati (ap, RADPLOTS)))
+	    } else
+		call apseti (ap, RADPLOTS, btoi (bval))
+	default:
+	    call printf ("Unknown or ambiguous colon command\7\n")
+	}
+
+	call sfree (sp)
+end
diff --git a/noao/digiphot/apphot/radprof/aprpfree.x b/noao/digiphot/apphot/radprof/aprpfree.x
new file mode 100644
index 00000000..2f16e03a
--- /dev/null
+++ b/noao/digiphot/apphot/radprof/aprpfree.x
@@ -0,0 +1,60 @@
+include "../lib/apphotdef.h"
+include "../lib/radprofdef.h"
+
+# AP_RPFREE -- Procedure to free the radial profile fitting structure.
+
+procedure ap_rpfree (ap)
+
+pointer	ap		# pointer to the apphot structure
+
+begin
+	if (ap == NULL)
+	    return
+	if (AP_NOISE(ap) != NULL)
+	    call ap_noisecls (ap)
+	if (AP_PCENTER(ap) != NULL)
+	    call ap_ctrcls (ap)
+	if (AP_PDISPLAY(ap) != NULL)
+	    call ap_dispcls (ap)
+	if (AP_POLY(ap) != NULL)
+	    call ap_ycls (ap)
+	if (AP_PPHOT(ap) != NULL)
+	    call ap_photcls (ap)
+	if (AP_PPSF(ap) != NULL)
+	    call ap_psfcls (ap)
+	if (AP_RPROF(ap) != NULL)
+	    call ap_rpcls (ap)
+	if (AP_PSKY(ap) != NULL)
+	    call ap_skycls (ap)
+	if (AP_IMBUF(ap) != NULL)
+	    call mfree (AP_IMBUF(ap), TY_REAL)
+	if (AP_MW(ap) != NULL)
+	    call mw_close (AP_MW(ap))
+	call mfree (ap, TY_STRUCT)
+end
+
+
+# AP_RPCLS -- Procedure to closee up the radial profile fitting arrays.
+
+procedure ap_rpcls (ap)
+
+pointer	ap			# pointer to apphot structure
+
+pointer	rprof
+
+begin
+	rprof = AP_RPROF(ap)
+	if (rprof == NULL)
+	    return
+	#if (AP_RPIX(rprof) != NULL)
+	    #call mfree (AP_RPIX(rprof), TY_REAL)
+	if (AP_RPDIST(rprof) != NULL)
+	    call mfree (AP_RPDIST(rprof), TY_REAL)
+	if (AP_INTENSITY(rprof) != NULL)
+	    call mfree (AP_INTENSITY(rprof), TY_REAL)
+	if (AP_DINTENSITY(rprof) != NULL)
+	    call mfree (AP_DINTENSITY(rprof), TY_REAL)
+	if (AP_TINTENSITY(rprof) != NULL)
+	    call mfree (AP_TINTENSITY(rprof), TY_REAL)
+	call mfree (rprof, TY_STRUCT)
+end
diff --git a/noao/digiphot/apphot/radprof/aprpindef.x b/noao/digiphot/apphot/radprof/aprpindef.x
new file mode 100644
index 00000000..4d92d615
--- /dev/null
+++ b/noao/digiphot/apphot/radprof/aprpindef.x
@@ -0,0 +1,69 @@
+include "../lib/apphotdef.h"
+include "../lib/radprofdef.h"
+include "../lib/photdef.h"
+include "../lib/phot.h"
+include "../lib/radprof.h"
+
+# AP_RPINDEF -- Routine to return INDEF valued photometry and radial profile
+# buffers.
+
+procedure ap_rpindef (ap)
+
+pointer	ap		# pointer to the apphot structure
+
+pointer	phot, rprof
+
+begin
+	phot = AP_PPHOT(ap)
+	rprof = AP_RPROF(ap)
+
+	AP_RPFWHM(rprof) = INDEFR
+	AP_INORM(rprof) = INDEFR
+	AP_TINORM(rprof) = INDEFR
+
+	call amovkr (INDEFR, Memr[AP_INTENSITY(rprof)], AP_RPNPTS(rprof))
+	call amovkr (INDEFR, Memr[AP_TINTENSITY(rprof)], AP_RPNPTS(rprof))
+	call amovkd (0.0d0, Memd[AP_AREA(phot)], AP_NAPERTS(phot))
+	call amovkd (0.0d0, Memd[AP_SUMS(phot)], AP_NAPERTS(phot))
+	call amovkr (INDEFR, Memr[AP_MAGS(phot)], AP_NAPERTS(phot))
+	call amovkr (INDEFR, Memr[AP_MAGERRS(phot)], AP_NAPERTS(phot))
+end
+
+
+# AP_MAXAP -- Procedure to setup the maximum number of apertures for phot.
+
+procedure ap_maxap (ap, pier)
+
+pointer	ap		# pointer to the apphot structure
+int	pier		# photometric error
+
+int	i
+pointer	phot, rprof
+real	dxc1, dxc2, dyc1, dyc2, rdist, rapert
+
+begin
+	phot = AP_PPHOT(ap)
+	rprof = AP_RPROF(ap)
+
+	dxc1 = AP_RPXC(rprof) - 0.5
+	dxc2 = AP_RPNX(rprof) - AP_RPXC(rprof) + 0.5
+	dyc1 = AP_RPYC(rprof) - 0.5
+	dyc2 = AP_RPNY(rprof) - AP_RPYC(rprof) + 0.5
+
+	# Compute the maximum aperture.
+	AP_NMAXAP(phot) = 0
+	rdist = min (abs (dxc1), abs (dxc2), abs (dyc1), abs (dyc2))
+	do i = 1, AP_NAPERTS(phot) {
+	    rapert = AP_SCALE(ap) * Memr[AP_APERTS(phot)+i-1]
+	    if (rapert <= rdist) {
+		AP_NMAXAP(phot) = i
+	    } else {
+		break
+	    }
+	}
+
+	if (AP_NMAXAP(phot) < AP_NAPERTS(phot))
+	    pier = AP_APERT_OUTOFBOUNDS
+	else
+	    pier = AP_OK
+end
diff --git a/noao/digiphot/apphot/radprof/aprpinit.x b/noao/digiphot/apphot/radprof/aprpinit.x
new file mode 100644
index 00000000..49bea62c
--- /dev/null
+++ b/noao/digiphot/apphot/radprof/aprpinit.x
@@ -0,0 +1,77 @@
+include "../lib/apphotdef.h"
+include "../lib/radprofdef.h"
+include "../lib/phot.h"
+
+# AP_RPINIT - Procedure to initialize the radial profile fitting structure.
+
+procedure ap_rpinit (ap, cfunction, cbox, sfunction, annulus, dannulus,
+        aperts, napert, radius, step, fwhmpsf, noise)
+
+pointer	ap		# pointer to the apphot structure
+int	cfunction	# centering algorithm
+real	cbox		# half width of the centering box
+int	sfunction	# sky fitting algorithm
+real	annulus		# radius of sky annulus
+real	dannulus	# width of sky annulus
+real	aperts[ARB]	# array of apertures
+int	napert		# number of apertures
+real	radius		# radius of fitting region
+real	step		# step size of output
+real	fwhmpsf		# FWHM of the PSF
+int	noise		# Noise model
+
+begin
+	# Set the image dependent parameters.
+	call malloc (ap, LEN_APSTRUCT, TY_STRUCT)
+
+	# Set up the global apphot package defaults.
+	call ap_defsetup (ap, fwhmpsf)
+
+	# Set up the noise model parameters.
+	call ap_noisesetup (ap, noise)
+
+	# Set up the centering algorithm parameters.
+	call ap_ctrsetup (ap, cfunction, cbox)
+	    
+	# Set up the sky fitting parameters.
+	call ap_skysetup (ap, sfunction, annulus, dannulus)
+
+	# Set up the photometry parameters.
+	call ap_photsetup (ap, aperts, napert, AP_PWCONSTANT)
+
+	# Set up the radial profile fitting parameters.
+	call ap_rpsetup (ap, radius, step)
+
+	# Set up the display options.
+	call ap_dispsetup (ap)
+
+	# Set psf fitting and polyphot structures to null.
+	AP_PPSF(ap) = NULL
+	AP_POLY(ap) = NULL
+end
+
+
+# AP_RPSETUP -- Procedure to set up the radial profle fitting parameters.
+
+procedure ap_rpsetup (ap, radius, step)
+
+pointer	ap		# pointer to apphot structure
+real	radius		# radius of psf to be fit
+real	step		# step size
+
+pointer	rprof
+
+begin
+	call malloc (AP_RPROF(ap), LEN_RPSTRUCT, TY_STRUCT)
+	rprof = AP_RPROF(ap)
+	AP_RPXCUR(rprof) = INDEFR
+	AP_RPYCUR(rprof) = INDEFR
+	AP_RPRADIUS(rprof) = radius
+	AP_RPSTEP(rprof) = step
+	AP_RPIX(rprof) = NULL
+	AP_RPNPTS(rprof) = int (AP_RPRADIUS(rprof) / AP_RPSTEP(rprof)) + 1
+	call malloc (AP_RPDIST(rprof), AP_RPNPTS(rprof), TY_REAL)
+	call malloc (AP_INTENSITY(rprof), AP_RPNPTS(rprof), TY_REAL)
+	call malloc (AP_DINTENSITY(rprof), AP_RPNPTS(rprof), TY_REAL)
+	call malloc (AP_TINTENSITY(rprof), AP_RPNPTS(rprof), TY_REAL)
+end
diff --git a/noao/digiphot/apphot/radprof/aprpplot.x b/noao/digiphot/apphot/radprof/aprpplot.x
new file mode 100644
index 00000000..dee441f1
--- /dev/null
+++ b/noao/digiphot/apphot/radprof/aprpplot.x
@@ -0,0 +1,307 @@
+include <gset.h>
+include <pkg/gtools.h>
+include "../lib/apphotdef.h"
+include "../lib/apphot.h"
+include "../lib/center.h"
+include "../lib/fitsky.h"
+include "../lib/photdef.h"
+include "../lib/phot.h"
+include "../lib/radprofdef.h"
+include "../lib/radprof.h"
+
+define	IMIN	-0.1		# Minimum intensity value for plot
+define	IMAX	1.1		# Maximum intensity value for plot
+
+# AP_RPPLOT -- Procedure to plot the radial profile.
+
+procedure ap_rpplot (ap, sid, gd, makeplots)
+
+pointer	ap		# pointer to the apphot structure
+int	sid		# output file id number (not used)
+pointer	gd		# pointer to the plot stream
+int	makeplots	# make plots on the screen ?
+
+int	nxpts, nypts, nrpts
+pointer	rprof, gt
+real	rmin, rmax, inorm, x1, x2, y1, y2, u1, u2, v1, v2
+int	apstati()
+pointer	ap_gtinit()
+real	apstatr()
+
+begin
+	# Return if no graphics stream.
+	if (gd == NULL || makeplots == NO)
+	    return
+
+	# Return if the center or sky is undefined.
+	if (IS_INDEFR(apstatr (ap, XCENTER)) || IS_INDEFR(apstatr (ap,
+	    YCENTER)) || IS_INDEFR (apstatr (ap, SKY_MODE)))
+	    return
+
+	# Return if there are no pixels.
+	rprof = AP_RPROF(ap)
+	if (AP_RPIX(rprof) == NULL)
+	    return
+
+	# Set up some useful constants.
+	rmin = 0.0
+	rmax = apstatr (ap, SCALE) * apstatr (ap, RPRADIUS)
+	nxpts = AP_RPNX(rprof)
+	nypts = AP_RPNY(rprof)
+	nrpts = apstati (ap, RPNPTS)
+	inorm = apstatr (ap, INORM)
+
+	# Reopen the work station.
+	call greactivate (gd, 0)
+
+	# Save old viewport and coordinates.
+	call ggwind (gd, x1, x2, y1, y2)
+	call ggview (gd, u1, u2, v1, v2)
+
+	# Set up the labels and annotate the plot.
+	gt = ap_gtinit (AP_IMROOT(ap), apstatr (ap, OXINIT), apstatr (ap,
+	    OYINIT))
+	call gclear (gd)
+	call ap_rpset (gd, gt, ap, rmin, rmax, IMIN, IMAX)
+	call ap_rpannotate (gd, ap, rmin, rmax, IMIN, IMAX)
+
+	# Plot the intensity and total intensity.
+	call ap_plothist (gd, gt, Memr[AP_RPDIST(rprof)],
+	    Memr[AP_INTENSITY(rprof)], nrpts, "line", GL_SOLID)
+	call ap_plothist (gd, gt, Memr[AP_RPDIST(rprof)],
+	    Memr[AP_TINTENSITY(rprof)], nrpts, "line", GL_DOTDASH)
+
+	# Plot the points.
+	call gswind (gd, rmin, rmax, (IMIN * inorm), (IMAX * inorm))
+	call rp_ptsplot (gd, gt, Memr[AP_RPIX(rprof)], nxpts, nypts,
+	    AP_RPXC(rprof), AP_RPYC(rprof))
+
+	# Restore old viewport and world coordinates.
+	call gsview (gd, u1, u2, v1, v2)
+	call gswind (gd, x1, x2, y1, y2)
+
+	call ap_gtfree (gt)
+	call gdeactivate (gd, 0)
+end
+
+
+# AP_RPSET -- Procedure to set up the parameters for the radial profile
+# plot.
+
+procedure ap_rpset (gd, gt, ap, xmin, xmax, ymin, ymax)
+
+pointer	gd		# graphics stream
+pointer	gt		# gtools pointer
+pointer	ap		# apphot pointer
+real	xmin, xmax	# minimum and maximum radial distance
+real	ymin, ymax	# minimum and maximum of the y axis
+
+int	fd, naperts
+pointer	sp, str, tstr, temp
+real	scale, aspect, vx1, vx2, vy1, vy2
+int	stropen(), apstati()
+real	apstatr(), gstatr()
+
+begin
+	call smark (sp)
+	call salloc (str, 6 * SZ_LINE, TY_CHAR)
+	call salloc (tstr, SZ_LINE, TY_CHAR)
+	naperts = apstati (ap, NAPERTS)
+	call salloc (temp, naperts, TY_REAL)
+
+	# Open the title string. 
+	fd = stropen (Memc[str], 6 * SZ_LINE, WRITE_ONLY)
+
+	# Encode the sysid.
+	call sysid (Memc[tstr], SZ_LINE)
+	call fprintf (fd, "%s\n")
+	    call pargstr (Memc[tstr])
+
+	# Encode the center string
+	call fprintf (fd,
+	    "Center: xc=%0.2f yc=%0.2f xerr=%0.2f yerr=%0.2f\n")
+	    call pargr (apstatr (ap, OXCENTER))
+	    call pargr (apstatr (ap, OYCENTER))
+	    call pargr (apstatr (ap, XERR))
+	    call pargr (apstatr (ap, YERR))
+
+	# Encode the sky string
+	call fprintf (fd,
+	    "Sky: value=%0.2f sigma=%0.2f skew=%0.2f nsky=%d nreject=%d\n")
+	    call pargr (apstatr (ap, SKY_MODE))
+	    call pargr (apstatr (ap, SKY_SIGMA))
+	    call pargr (apstatr (ap, SKY_SKEW))
+	    call pargi (apstati (ap, NSKY))
+	    call pargi (apstati (ap, NSKY_REJECT))
+
+	# Encode the value of the magnitude at the maximum aperture.
+	call fprintf (fd, "Photometry: fwhmpsf=%0.3f  maxapert=")
+	    call pargr (apstatr (ap, RPFWHM))
+	call ap_arrayr (ap, APERTS, Memr[temp])
+	call amulkr (Memr[temp], apstatr (ap, SCALE), Memr[temp], naperts)
+	call fprintf (fd, "%0.2f  mags=")
+	    call pargr (Memr[temp+naperts-1])
+	call ap_arrayr (ap, MAGS, Memr[temp])
+	call fprintf (fd, "%0.3f\n")
+	    call pargr (Memr[temp+naperts-1])
+
+	# Encode the parameter string.
+	call fprintf (fd,
+	    "Fit: spline3 order=%d krej=%0.1f sigma np=%d nprej=%d\n")
+	    call pargi (apstati (ap, RPORDER))
+	    call pargr (apstatr (ap, RPKSIGMA))
+	    call pargi (apstati (ap, RPNDATA))
+	    call pargi (apstati (ap, RPNDATAREJ))
+
+	# Encode the title.
+	call gt_gets (gt, GTTITLE, Memc[tstr], SZ_LINE)
+	call fprintf (fd, "%s\n\n")
+	    call pargstr (Memc[tstr])
+
+	call strclose (fd)
+
+	aspect = gstatr (gd, G_ASPECT)
+	scale = apstatr (ap, SCALE)
+	call gsetr (gd, G_ASPECT, 0.70)
+	call gseti (gd, G_WCS, 2)
+
+	# Draw and label the axes.
+	call gseti (gd, G_XDRAWAXES, 2)
+	call gswind (gd, xmin / scale, xmax / scale, ymin, ymax)
+	call glabax (gd, Memc[str], "", "Intensity")
+	call gseti (gd, G_YDRAWAXES, 0)
+	call gseti (gd, G_XDRAWAXES, 1)
+	call ggview (gd, vx1, vx2, vy1, vy2)
+	call gsview (gd, vx1, vx2, vy1, vy2)
+	call gswind (gd, xmin, xmax, ymin, ymax)
+	call glabax (gd, "",
+	    "Radial Distance (lower-pixels, upper-scale units)", "")
+
+	# Reset the axes parameters.
+	call gseti (gd, G_YDRAWAXES, 3)
+	call gseti (gd, G_XDRAWAXES, 3)
+	call gsetr (gd, G_ASPECT, aspect)
+
+	# Set the plot type.
+	call gt_sets (gt, GTTYPE, "line")
+
+	call sfree (sp)
+end
+
+
+# AP_RPANNOTATE -- Procedure to annotate the radial plot in radprof.
+
+procedure ap_rpannotate (gd, ap, xmin, xmax, ymin, ymax)
+
+pointer	gd		# graphics stream
+pointer	ap		# apphot structure
+real	xmin, xmax	# min and max of x axis
+real	ymin, ymax	# min and max of y axis
+
+int	naperts
+pointer	sp, str, temp
+real	scale, rpfwhm, annulus, dannulus, inorm, tinorm
+int	apstati()
+real	apstatr()
+
+begin
+	# Allocate working space.
+	naperts = apstati (ap, NAPERTS)
+	call smark (sp)
+	call salloc (str, SZ_LINE, TY_CHAR)
+	call salloc (temp, naperts, TY_REAL)
+	call gseti (gd, G_PLTYPE, GL_DASHED)
+
+	# Draw the zero level line.
+	call gamove (gd, xmin, 0.0)
+	call gadraw (gd, xmax, 0.0)
+
+	# Draw the half power point.
+	call gamove (gd, xmin, 0.5)
+	call gadraw (gd, xmax, 0.5)
+
+	# Draw the unit normalization value.
+	call gamove (gd, xmin, 1.0)
+	call gadraw (gd, xmax, 1.0)
+
+	# Plot the full width half maximum of the radial profile.
+	scale = apstatr (ap, SCALE)
+	rpfwhm = apstatr (ap, RPFWHM) / 2.0
+	if (rpfwhm >= xmin && rpfwhm <= xmax) {
+	    call gamove (gd, rpfwhm, ymin)
+	    call gadraw (gd, rpfwhm, ymax)
+	    call sprintf (Memc[str], SZ_LINE, "hwhm = %0.2f")
+	        call pargr (rpfwhm)
+	    call gtext (gd, rpfwhm, 0.0, Memc[str], "q=h;u=180;p=r")
+	}
+
+	# Mark the sky annuli.
+	annulus = scale * apstatr (ap, ANNULUS)
+	dannulus = scale * (apstatr (ap, ANNULUS) + apstatr (ap, DANNULUS))
+	if (annulus >= xmin && annulus <= xmax) {
+	    call gamove (gd, annulus, ymin)
+	    call gadraw (gd, annulus, ymax)
+	    call sprintf (Memc[str], SZ_LINE, "inner sky radius = %0.2f")
+	        call pargr (annulus)
+	    call gtext (gd, annulus, 0.0, Memc[str], "q=h;u=180;p=r")
+	}
+	if (dannulus >= xmin && dannulus <= xmax) {
+	    call gamove (gd, dannulus, ymin)
+	    call gadraw (gd, dannulus, ymax)
+	    call sprintf (Memc[str], SZ_LINE, "outer sky radius = %0.2f")
+	        call pargr (dannulus)
+	    call gtext (gd, dannulus, 0.0, Memc[str], "q=h;u=180;p=r")
+	}
+
+	# Plot the aperture value.
+	call ap_arrayr (ap, APERTS, Memr[temp])
+	call amulkr (Memr[temp], scale, Memr[temp], naperts)
+	call gseti (gd, G_PLTYPE, GL_SOLID)
+	if (Memr[temp+naperts-1] >= xmin && Memr[temp+naperts-1] <= xmax) {
+    	    call gamove (gd, Memr[temp+naperts-1], ymin)
+	    call gadraw (gd, Memr[temp+naperts-1], ymax)
+	    call sprintf (Memc[str], SZ_LINE, "maxapert = %0.2f")
+	        call pargr (Memr[temp+naperts-1])
+	    call gtext (gd, Memr[temp+naperts-1], 0.0, Memc[str],
+	        "q=h;u=180;p=r")
+	}
+	call gseti (gd, G_PLTYPE, GL_DASHED)
+
+	# Plot the inorm value.
+	inorm = apstatr (ap, INORM)
+	call sprintf (Memc[str], SZ_LINE, "inorm = %0.2f")
+	    call pargr (inorm)
+	call gtext (gd, 0.0, 1.0, Memc[str], "q=h")
+
+	# Plot the tinorm value.
+	tinorm = apstatr (ap, TNORM)
+	call sprintf (Memc[str], SZ_LINE, "tinorm = %0.2f")
+	    call pargr (tinorm)
+	call gtext (gd, xmax, 1.0, Memc[str], "q=h;h=r")
+
+	call sfree (sp)
+end
+
+
+# RP_PTSPLOT -- Plot the radial profile plots.
+
+procedure rp_ptsplot (gd, gt, pixels, nx, ny, wx, wy)
+
+pointer	gd		# pointer to the graphics stream
+pointer	gt		# pointer to the gtools structure
+real	pixels[nx,ARB]	# subraster of pixel values
+int	nx, ny		# dimensions of the pixel subraster
+real	wx, wy		# x and y coordinates of the center
+
+int	i
+pointer	sp, rtemp
+
+begin
+	call smark (sp)
+	call salloc (rtemp, nx, TY_REAL)
+	do i = 1, ny {
+	    call ap_ijtor (Memr[rtemp], nx, i, wx, wy)
+	    call ap_plotrad (gd, gt, Memr[rtemp], pixels[1,i], nx, "plus")
+	}
+	call sfree (sp)
+end
diff --git a/noao/digiphot/apphot/radprof/iradprof.key b/noao/digiphot/apphot/radprof/iradprof.key
new file mode 100644
index 00000000..1c5a8974
--- /dev/null
+++ b/noao/digiphot/apphot/radprof/iradprof.key
@@ -0,0 +1,20 @@
+                    Interactive Radprof Setup Menu
+
+	v	Mark and verify the critical parameters (f,c,s,a,d,r,w,x)
+
+	f	Mark and verify the psf full-width half-maximum
+	s	Mark and verify the standard deviation of the background
+	l	Mark and verify the minimum good data value
+	u	Mark and verify the maximum good data value
+
+	c	Mark and verify the centering box width
+	n	Mark and verify the cleaning radius
+	p	Mark and verify the clipping radius
+
+	a	Mark and verify the inner radius of the sky annulus
+	d	Mark and verify the width of the sky annulus
+	g	Mark and verify the region growing radius
+
+	r	Mark and verify the photometry aperture radii
+	w	Mark and verify the radius of the radial profile
+	x	Mark and verify the step size of radial profile
diff --git a/noao/digiphot/apphot/radprof/mkpkg b/noao/digiphot/apphot/radprof/mkpkg
new file mode 100644
index 00000000..8ef786bc
--- /dev/null
+++ b/noao/digiphot/apphot/radprof/mkpkg
@@ -0,0 +1,58 @@
+RADPROF Fitting Task Routines
+
+$checkout libpkg.a ".."
+$update libpkg.a
+$checkin libpkg.a ".."
+$exit
+
+libpkg.a:
+	apbradprof.x	<fset.h>		../lib/apphot.h         \
+			../lib/center.h		../lib/fitsky.h         \
+			../lib/display.h
+	apgrpars.x	../lib/center.h		../lib/fitsky.h         \
+			../lib/phot.h		../lib/display.h	\
+			../lib/noise.h		../lib/radprof.h
+	approfsetup.x	../lib/center.h		../lib/fitsky.h         \
+			../lib/display.h
+	apprprof.x	../lib/apphotdef.h	../lib/apphot.h         \
+			../lib/center.h		../lib/fitsky.h         \
+			../lib/photdef.h	../lib/phot.h		\
+			../lib/radprof.h
+	apradprof.x	<ctype.h>		<gset.h>		\
+			../lib/apphot.h		../lib/center.h         \
+			../lib/fitsky.h		../lib/radprof.h	\
+			../lib/display.h        <imhdr.h>
+	aprconfirm.x	../lib/apphot.h		../lib/noise.h          \
+			../lib/center.h         ../lib/fitsky.h         \
+			../lib/phot.h           ../lib/radprof.h
+	aprferrors.x	../lib/phot.h		../lib/radprof.h
+	aprmmeasure.x   <math/curfit.h>
+	aprpars.x	../lib/radprof.h	../lib/display.h 
+	aprpbuf.x	<imhdr.h>		../lib/apphotdef.h	\
+			../lib/radprofdef.h	../lib/radprof.h
+	aprpcolon.x	../lib/apphot.h		../lib/fitsky.h         \
+			../lib/center.h		../lib/phot.h		\
+			../lib/radprof.h	../lib/noise.h	        \
+			../lib/display.h
+	aprpfree.x	../lib/apphotdef.h	../lib/radprofdef.h
+	aprpindef.x	../lib/apphotdef.h	../lib/radprofdef.h	\
+			../lib/radprof.h	../lib/photdef.h	\
+			../lib/phot.h
+	aprpinit.x	../lib/apphotdef.h	../lib/radprofdef.h	\
+			../lib/phot.h
+	aprpplot.x	<gset.h>		<pkg/gtools.h>		\
+			../lib/apphotdef.h	../lib/photdef.h	\
+			../lib/radprof.h	../lib/phot.h		\
+			../lib/fitsky.h		../lib/radprofdef.h	\
+			../lib/center.h		../lib/apphot.h
+	apfrprof.x	<math/curfit.h>		<math/iminterp.h>	\
+			<gset.h>		../lib/fitskydef.h      \
+			../lib/apphotdef.h	../lib/radprofdef.h	\
+			../lib/phot.h		../lib/photdef.h	\
+			../lib/radprof.h        <math.h>                \
+			<mach.h>                "../lib/noisedef.h"     \
+			../lib/apphot.h
+	rprofshow.x	../lib/display.h	../lib/radprof.h
+	t_radprof.x	<fset.h>		<gset.h>		\
+			../lib/apphot.h         <imhdr.h>
+	;
diff --git a/noao/digiphot/apphot/radprof/radprof.key b/noao/digiphot/apphot/radprof/radprof.key
new file mode 100644
index 00000000..4204743f
--- /dev/null
+++ b/noao/digiphot/apphot/radprof/radprof.key
@@ -0,0 +1,116 @@
+	Interactive Keystroke Commands
+
+?	Print help
+:	Colon commands
+v	Verify the critical parameters
+w	Store the current parameters
+d	Plot radial profile of current star
+i	Interactively set parameters using current star
+c	Fit center of current star
+t	Fit sky around cursor
+a       Average sky values fit around several cursor positions
+s	Fit sky around the current star 
+p	Fit star using current sky
+o	Fit star using current sky, output results
+f	Fit current star
+spbar	Fit current star, output results
+m	Move to next star in coordinate list
+n	Fit next star in coordinate list, output results
+l	Fit remaining stars in coordinate list, output results	
+r	Rewind the coordinate list
+e	Print error messages
+q	Exit task
+
+
+	Colon Commands
+
+:show	[data/center/sky/fit]	List the parameters
+:m [n]	Move to next [nth] object in coordinate list
+:n [n]	Fit next [nth] object in coordinate list, output results
+
+
+	Colon Parameter Editing Commands
+
+# Image and file name parameters
+
+:image		[string]	Image name
+:coords		[string]	Coordinate file name
+:output		[string]	Output file name
+
+# Data dependent parameters
+
+:scale		[vlaue]		Image scale (units per pixel)
+:fwhmpsf	[value]		Full-width half-maximum of psf (scale units)
+:emission	[y/n]		Emission features (y), absorption (n)
+:sigma		[value]		Standard deviation of sky (counts)
+:datamin	[value]		Minimum good pixel value (counts)
+:datamax	[value]		Maximum good pixel value (counts)
+
+# Noise parameters
+
+:noise		[string]	Noise model (constant|poisson)
+:gain		[string]	Gain image header keyword
+:ccdread	[string]	Readout noise image header keyword
+:epadu		[value]		Gain (electrons per adu)
+:readnoise	[value]		Readout noise (electrons)
+
+# Observing parameters
+
+:exposure	[value]		Exposure time image header keyword
+:airmass	[string]	Airmass image header keyword
+:filter		[string]	Filter image header keyword
+:obstime	[string]	Time of observation image header keyword
+:itime		[value]		Integration time (time units)
+:xairmass	[value]		Airmass value (number)
+:ifilter	[string]	Filter id string
+:otime		[string]	Time of observation (time units)
+
+# Centering algorithm parameters
+
+:calgorithm	[string]	Centering algorithm
+:cbox		[value]		Width of the centering box (scale units)
+:cthreshold	[value]		Centering intensity threshold (sigma)
+:cmaxiter	[value]		Maximum number of iterations
+:maxshift	[value]		Maximum center shift (scale units)
+:minsnratio	[value]		Minimum S/N ratio for centering
+:clean		[y/n]		Clean subraster before centering
+:rclean		[value]		Cleaning radius (scale units)
+:rclip		[value]		Clipping radius (scale units)
+:kclean		[value]		Clean K-sigma rejection limit (sigma)
+
+# Sky fitting algorithm parameters
+
+:salgorithm	[string]	Sky fitting algorithm
+:skyvalue	[value]		User supplied sky value (counts)
+:annulus	[value]		Inner radius of sky annulus (scale units)
+:dannulus	[value]		Width of sky annulus (scale units)
+:khist		[value]		Sky histogram extent (+/- sigma)
+:binsize	[value]		Resolution of sky histogram (sigma)
+:sloclip	[value]		Low-side clipping factor in percent
+:shiclip	[value]		High-side clipping factor in percent
+:smaxiter	[value]		Maximum number of iterations
+:smooth		[y/n]		Lucy smooth the sky histogram
+:snreject	[value]		Maximum number of rejection cycles
+:sloreject	[value]		Low-side pixel rejection limits (sky sigma)
+:shireject	[value]		High-side pixel rejection limits (sky sigma)
+:rgrow		[value]		Region growing radius (scale units)
+
+# Photometry parameters
+
+:apertures	[string]	List of apertures (scale units)
+:zmag		[value]		Zero point of magnitude scale
+
+# Profile fitting parameters
+
+:radius		[value]		Maximum profile radius (scale units)
+:step		[value]		Step size for computed profile (scale units)
+:order		[value]		Number of spline pieces in fit
+:kreject	[value]		K-sigma rejection for fit (fit sigma)
+:nreject	[value]		Maximum number of rejection cycles
+
+# Marking and plotting parameters
+
+:mkcenter	[y/n]		Mark computed centers on display
+:mksky		[y/n]		Mark the sky annuli on the display
+:mkapert	[y/n]		Mark apertures on the display
+:radplot	[y/n]		Plot the radial profile
diff --git a/noao/digiphot/apphot/radprof/rprofshow.x b/noao/digiphot/apphot/radprof/rprofshow.x
new file mode 100644
index 00000000..c4264ede
--- /dev/null
+++ b/noao/digiphot/apphot/radprof/rprofshow.x
@@ -0,0 +1,75 @@
+include "../lib/display.h"
+include "../lib/radprof.h"
+
+# AP_RPROFSHOW -- Procedure to display all the radprof parameters.
+
+procedure ap_rprofshow (ap)
+
+pointer	ap	# pointer to the apphot strucuture
+
+bool	itob()
+int	apstati()
+
+begin
+	call ap_nshow (ap)
+	call printf ("\n")
+	call ap_cpshow (ap)
+	call printf ("\n")
+	call ap_spshow (ap)
+	call printf ("\n")
+	call ap_mpshow (ap)
+	call printf ("\n")
+	call ap_rppshow (ap)
+	call printf ("    %s = %b\n")
+	    call pargstr (KY_RADPLOTS)
+	    call pargb (itob (apstati (ap, RADPLOTS)))
+end
+
+
+# AP_RPSHOW -- Procedure to display radprof parameters.
+
+procedure ap_rpshow (ap)
+
+pointer	ap		# pointer to apphot structure
+
+bool	itob()
+int	apstati()
+
+begin
+	call ap_nshow (ap)
+	call ap_rppshow (ap)
+	call printf ("    %s = %b\n")
+	    call pargstr (KY_RADPLOTS)
+	    call pargb (itob (apstati (ap, RADPLOTS)))
+end
+
+
+# AP_RPPSHOW -- Procedure to display radprof parameters.
+
+procedure ap_rppshow (ap)
+
+pointer	ap		# pointer to apphot structure
+
+int	apstati()
+real	apstatr()
+
+begin
+	# Print the radial profile characteristics.
+	call printf ("Radial Profile Fitting Parameters\n")
+	call printf ("    %s = %g %s    %s = %g %s\n")
+	    call pargstr (KY_RPRADIUS)
+	    call pargr (apstatr (ap, RPRADIUS))
+	    call pargstr (UN_RSCALEUNIT)
+	    call pargstr (KY_RPSTEP)
+	    call pargr (apstatr (ap, RPSTEP))
+	    call pargstr (UN_RSCALEUNIT)
+
+	call printf ("    %s = %d    %s = %g %s    %s = %d\n")
+	    call pargstr (KY_RPORDER)
+	    call pargi (apstati (ap, RPORDER))
+	    call pargstr (KY_RPKSIGMA)
+	    call pargr (apstatr (ap, RPKSIGMA))
+	    call pargstr (UN_RSIGMA)
+	    call pargstr (KY_RPNREJECT)
+	    call pargi (apstati (ap, RPNREJECT))
+end
diff --git a/noao/digiphot/apphot/radprof/t_radprof.x b/noao/digiphot/apphot/radprof/t_radprof.x
new file mode 100644
index 00000000..fda4c459
--- /dev/null
+++ b/noao/digiphot/apphot/radprof/t_radprof.x
@@ -0,0 +1,306 @@
+include <fset.h>
+include <gset.h>
+include <imhdr.h>
+include "../lib/apphot.h"
+
+# T_RADPROF -- Procedure to compute the radial profiles of a list of
+# objects.
+
+procedure t_radprof ()
+
+pointer image		# pointer to the name of the image
+pointer output		# pointer to the output file name
+pointer coords		# pointer to the coordinate file
+pointer plotfile	# pointer to the metacode plot file
+pointer graphics	# pointer to the graphics device
+pointer display		# pointer to the display device
+int	interactive	# interactive mode
+int	cache		# cache the input image
+int	verify		# verify the critical parameters
+int	update		# update the critical parameters
+int	verbose		# verbose mode
+
+pointer	sp, cname, outfname, ap, im, id, gd, mgd, str
+int	limlist, lclist, lolist, sid, lid, cl, out, pfd, root, stat
+int	imlist, clist, olist, wcs, memstat, req_size, old_size, buf_size
+
+pointer	immap(), gopen()
+int	imtlen(), imtgetim(), clplen(), clgfil(), btoi(), fnldir(), strncmp()
+int	strlen(), ap_radprof(), imtopenp(), clpopnu(), open(), clgwrd()
+int	ap_memstat(), sizeof()
+bool	clgetb(), streq()
+errchk	gopen
+
+begin
+	# Allocate working space.
+	call smark (sp)
+	call salloc (image, SZ_FNAME, TY_CHAR)
+	call salloc (output, SZ_FNAME, TY_CHAR)
+	call salloc (coords, SZ_FNAME, TY_CHAR)
+	call salloc (plotfile, SZ_FNAME, TY_CHAR)
+	call salloc (graphics, SZ_FNAME, TY_CHAR)
+	call salloc (display, SZ_FNAME, TY_CHAR)
+	call salloc (outfname, SZ_FNAME, TY_CHAR)
+	call salloc (cname, SZ_FNAME, TY_CHAR)
+	call salloc (str, SZ_FNAME, TY_CHAR)
+
+	# Set standard output to flush on newline.
+	call fseti (STDOUT, F_FLUSHNL, YES)
+
+	# Get input and output file names.
+	imlist = imtopenp ("image")
+	limlist = imtlen (imlist)
+	clist = clpopnu ("coords") 
+	lclist = clplen (clist)
+	olist = clpopnu ("output")
+	lolist = clplen (olist)
+
+	# Check that the image and coordinate list lengths match.
+	if (limlist < 1 || (lclist > 1 && lclist != limlist)) {
+	    call imtclose (imlist)
+	    call clpcls (clist)
+	    call clpcls (olist)
+	    call error (0, "Imcompatible image and coordinate list lengths")
+	}
+
+	# Check that image and output list lengths match.
+	if (lolist > 1 && lolist != limlist) {
+	    call imtclose (imlist)
+	    call clpcls (clist)
+	    call clpcls (olist)
+	    call error (0, "Imcompatible image and output list lengths")
+	}
+
+	call clgstr ("icommands.p_filename", Memc[cname], SZ_FNAME)
+	if (Memc[cname] != EOS)
+	    interactive = NO
+	#else if (lclist == 0)
+	    #interactive = YES
+	else
+	    interactive = btoi (clgetb ("interactive"))
+	cache = btoi (clgetb ("cache"))
+	verify = btoi (clgetb ("verify"))
+	update = btoi (clgetb ("update"))
+	verbose = btoi (clgetb ("verbose"))
+
+	# Get the radial profile fitting parameters.
+	call ap_grppars (ap)
+
+	# Verify the radial profile fitting parameters.
+	if (verify == YES && interactive == NO) {
+	    call ap_rconfirm (ap, NULL, 1)
+	    if (update == YES)
+		call ap_rpars (ap)
+	}
+
+        # Get the wcs information.
+        wcs = clgwrd ("wcsin", Memc[str], SZ_LINE, WCSINSTR)
+        if (wcs <= 0) {
+            call eprintf (
+                "Warning: Setting the input coordinate system to logical\n")
+            wcs = WCS_LOGICAL
+        }
+        call apseti (ap, WCSIN, wcs)
+        wcs = clgwrd ("wcsout", Memc[str], SZ_LINE, WCSOUTSTR)
+        if (wcs <= 0) {
+            call eprintf (
+                "Warning: Setting the output coordinate system to logical\n")
+            wcs = WCS_LOGICAL
+        }
+        call apseti (ap, WCSOUT, wcs)
+
+	# Get the graphics and display devices.
+	call clgstr ("graphics", Memc[graphics], SZ_FNAME)
+	call clgstr ("display", Memc[display], SZ_FNAME)
+
+	# Open the plot files.
+	if (interactive == YES) {
+	    if (Memc[graphics] == EOS)
+		gd = NULL
+	    else {
+		iferr {
+		    gd =  gopen (Memc[graphics], APPEND+AW_DEFER, STDGRAPH)
+		} then {
+		    call eprintf (
+			"Warning: Error opening graphics device.\n")
+		    gd = NULL
+		}
+	    }
+	    if (Memc[display] == EOS)
+		    id = NULL
+	    else if (streq (Memc[graphics], Memc[display]))
+		    id = gd
+	    else {
+		iferr {
+		    id = gopen (Memc[display], APPEND, STDIMAGE)
+		} then {
+		    call eprintf (
+		"Warning: Graphics overlay not available for display device.\n")
+		    id = NULL
+		}
+	    }
+	} else {
+	    gd = NULL
+	    id = NULL
+	}
+
+	# Open the plot metacode file.
+	call clgstr ("plotfile", Memc[plotfile], SZ_FNAME)
+	if (Memc[plotfile] == EOS)
+	    pfd = NULL
+	else
+	    pfd = open (Memc[plotfile], APPEND, BINARY_FILE)
+	if (pfd != NULL)
+	    mgd = gopen (Memc[graphics], NEW_FILE, pfd)
+	else
+	    mgd = NULL
+
+	# Begin looping over the image list.
+	sid = 1
+	while (imtgetim (imlist, Memc[image], SZ_FNAME) != EOF) {
+
+	    # Open the image.
+	    im = immap (Memc[image], READ_ONLY, 0)
+
+	    # Set the image display viewport.
+	    call apimkeys (ap, im, Memc[image])
+	    if ((id != NULL) && (id != gd))
+		call ap_gswv (id, Memc[image], im, 4)
+
+	    # Cache the input image pixels.
+            req_size = MEMFUDGE * IM_LEN(im,1) * IM_LEN(im,2) *
+                sizeof (IM_PIXTYPE(im))
+            memstat = ap_memstat (cache, req_size, old_size)
+            if (memstat == YES)
+                call ap_pcache (im, INDEFI, buf_size)
+
+	    # Open the coordinate file, where coords is assumed to be a simple
+	    # text file in which the x and y positions are in columns 1 and 2
+	    # respectively and all remaining fields are ignored.
+
+	    if (lclist <= 0) {
+		cl = NULL
+		call strcpy ("", Memc[outfname], SZ_FNAME)
+	    } else {
+		stat = clgfil (clist, Memc[coords], SZ_FNAME)
+		root = fnldir (Memc[coords], Memc[outfname], SZ_FNAME)
+		if (strncmp ("default", Memc[coords+root], 7) == 0 || root ==
+		    strlen (Memc[coords])) {
+		    call ap_inname (Memc[image], Memc[outfname], "coo",
+		        Memc[outfname], SZ_FNAME)
+		    lclist = limlist
+	            cl = open (Memc[outfname], READ_ONLY, TEXT_FILE)
+		} else if (stat != EOF) {
+		    call strcpy (Memc[coords], Memc[outfname], SZ_FNAME)
+	            cl = open (Memc[outfname], READ_ONLY, TEXT_FILE)
+		} else {
+		    call apstats (ap, CLNAME, Memc[outfname], SZ_FNAME)
+		    call seek (cl, BOF)
+		}
+	    }
+	    call apsets (ap, CLNAME, Memc[outfname])
+	    call apfroot (Memc[outfname], Memc[str], SZ_FNAME)
+	    call apsets (ap, CLROOT, Memc[str])
+
+	    # Open output text file, if output is "default", dir$default,
+	    # or a directory specification then the extension "prf" is added
+	    # to the image name and a suitable version number is appended to
+	    # the output name. If the output name is null then no output
+	    # file is created.
+
+	    if (lolist == 0) {
+		out = NULL
+		call strcpy ("", Memc[outfname], SZ_FNAME)
+	    } else {
+	        stat = clgfil (olist, Memc[output], SZ_FNAME)
+		root = fnldir (Memc[output], Memc[outfname], SZ_FNAME)
+		if (strncmp ("default", Memc[output+root], 7) == 0 || root ==
+		    strlen (Memc[output])) {
+	            call apoutname (Memc[image], Memc[outfname], "prf",
+		        Memc[outfname], SZ_FNAME)
+	            out = open (Memc[outfname], NEW_FILE, TEXT_FILE)
+		    lolist = limlist
+		} else if (stat != EOF) {
+		    call strcpy (Memc[output], Memc[outfname], SZ_FNAME)
+		    out = open (Memc[outfname], NEW_FILE, TEXT_FILE)
+		} else
+		    call apstats (ap, OUTNAME, Memc[outfname], SZ_FNAME)
+	    }
+	    call apsets (ap, OUTNAME, Memc[outfname])
+
+	    # Fit the radial profiles.
+	    if (interactive == NO) {
+	        if (Memc[cname] != EOS)
+		    stat = ap_radprof (ap, im, cl, NULL, mgd, NULL, out,
+		        sid, NO, cache)
+	        else  if (cl != NULL) {
+		    lid = 1
+	            call ap_bradprof (ap, im, cl, id, gd, mgd, out, sid, lid,
+		        verbose)
+		    stat = NO
+		} else
+		    stat = NO
+	    } else
+	        stat = ap_radprof (ap, im, cl, gd, mgd, id, out, sid, YES,
+		    cache)
+
+	    # Cleanup.
+	    call imunmap (im)
+	    if (cl != NULL) {
+		if (lclist > 1)
+	            call close (cl)
+	    }
+	    if (out != NULL && lolist != 1) {
+	        call close (out)
+		if (sid <= 1) {
+		    call apstats (ap, OUTNAME, Memc[outfname], SZ_FNAME)
+		    call delete (Memc[outfname])
+		}
+		sid = 1
+	    }
+
+	    # Uncache memory.
+	    call fixmem (old_size)
+
+	    if (stat == YES)
+		break
+
+	}
+
+	# If only one coordinate file for a list of images close list.
+	if (cl != NULL && lclist == 1)
+	    call close (cl)
+
+	# If only one output file for a list of images close list.
+	if (out != NULL && lolist == 1) {
+	    call close (out)
+	    if (sid <= 1) {
+		call apstats (ap, OUTNAME, Memc[outfname], SZ_FNAME)
+		call delete (Memc[outfname])
+	    }
+	}
+
+	# Close up plot files.
+	if (id == gd && id != NULL)
+	    call gclose (id)
+	else {
+	    if (gd != NULL)
+	        call gclose (gd)
+	    if (id != NULL)
+	        call gclose (id)
+	}
+	if (mgd != NULL)
+	    call gclose (mgd)
+	if (pfd != NULL)
+	    call close (pfd)
+
+	# Free the radial profile fitting structure.
+	call ap_rpfree (ap)
+
+	# Close up the lists.
+	call imtclose (imlist)
+	call clpcls (clist)
+	call clpcls (olist)
+
+	call sfree (sp)
+end
diff --git a/noao/digiphot/apphot/temp b/noao/digiphot/apphot/temp
new file mode 100644
index 00000000..afb44322
--- /dev/null
+++ b/noao/digiphot/apphot/temp
@@ -0,0 +1,8 @@
+-rw-rw-r--   1 davis        8974 Sep 30 15:53 t_center.x
+-rw-rw-r--   1 davis        8366 Sep 30 15:53 t_fitpsf.x
+-rw-rw-r--   1 davis        8829 Sep 30 15:54 t_fitsky.x
+-rw-rw-r--   1 davis        9968 Sep 30 15:57 t_phot.x
+-rw-rw-r--   1 davis        8526 Sep 30 15:57 t_qphot.x
+-rw-rw-r--   1 davis        9430 Sep 30 15:55 t_polyphot.x
+-rw-rw-r--   1 davis        8936 Sep 30 15:58 t_radprof.x
+-rw-rw-r--   1 davis        9933 Sep 30 15:56 t_wphot.x
diff --git a/noao/digiphot/apphot/test/README b/noao/digiphot/apphot/test/README
new file mode 100644
index 00000000..006e6988
--- /dev/null
+++ b/noao/digiphot/apphot/test/README
@@ -0,0 +1,5 @@
+This subdirectory contains test data for the installer/maintainer of
+the apphot package. The files beginning with fits contain test images
+of both real and artificial data. There are also some coordinate files
+supplied for these images. Eventually there will be some apphot demos
+which can be run to automatically test new releases of the software etc.
diff --git a/noao/digiphot/apphot/test/coords.dat b/noao/digiphot/apphot/test/coords.dat
new file mode 100644
index 00000000..f6458223
--- /dev/null
+++ b/noao/digiphot/apphot/test/coords.dat
@@ -0,0 +1,10 @@
+36 22 1 \40 
+26 22 1 \40
+36 42 1 \40  
+31 25 1 \40  
+29 34 1 \40 
+18 8 1 \40  
+21 26 1 \40 
+23 7 1 \40  
+8 23 1 \40 
+41 4 1 \40  
diff --git a/noao/digiphot/apphot/test/fits1.fits b/noao/digiphot/apphot/test/fits1.fits
new file mode 100644
index 00000000..85105ec8
--- /dev/null
+++ b/noao/digiphot/apphot/test/fits1.fits
diff --git a/noao/digiphot/apphot/test/fits2.fits b/noao/digiphot/apphot/test/fits2.fits
new file mode 100644
index 00000000..212a0c12
--- /dev/null
+++ b/noao/digiphot/apphot/test/fits2.fits
diff --git a/noao/digiphot/apphot/test/fits3.fits b/noao/digiphot/apphot/test/fits3.fits
new file mode 100644
index 00000000..ff7938e7
--- /dev/null
+++ b/noao/digiphot/apphot/test/fits3.fits
diff --git a/noao/digiphot/apphot/test/fits4.fits b/noao/digiphot/apphot/test/fits4.fits
new file mode 100644
index 00000000..5f9ca811
--- /dev/null
+++ b/noao/digiphot/apphot/test/fits4.fits
diff --git a/noao/digiphot/apphot/test/fits5.fits b/noao/digiphot/apphot/test/fits5.fits
new file mode 100644
index 00000000..3542fe3e
--- /dev/null
+++ b/noao/digiphot/apphot/test/fits5.fits
diff --git a/noao/digiphot/apphot/test/polygons.dat b/noao/digiphot/apphot/test/polygons.dat
new file mode 100644
index 00000000..666b9df7
--- /dev/null
+++ b/noao/digiphot/apphot/test/polygons.dat
@@ -0,0 +1,6 @@
+36 22 1 \40 
+26 22 1 \40
+36 42 1 \40  
+31 25 1 \40  
+29 34 1 \40 
+;
diff --git a/noao/digiphot/apphot/wphot.par b/noao/digiphot/apphot/wphot.par
new file mode 100644
index 00000000..126d52ce
--- /dev/null
+++ b/noao/digiphot/apphot/wphot.par
@@ -0,0 +1,24 @@
+# WPHOT parameters
+
+image,f,a,,,,"The input image(s)"
+skyfile,f,a,"",,,"The input sky file(s)"
+coords,f,h,"",,,"The input coordinate file(s) (default: image.coo.?)"
+output,f,h,"default",,,The output photometry file(s) (default: image.omag.?)"
+plotfile,f,h,"",,,"The output plot metacode file"
+datapars,pset,h,"",,,"Data dependent parameters"
+centerpars,pset,h,"",,,"Centering parameters"
+fitskypars,pset,h,"",,,"Sky fitting parameters"
+photpars,pset,h,,,,"Photometry parameters"
+interactive,b,h,yes,,,"Interactive mode ?"
+radplots,b,h,no,,,"Plot radial profiles in interactive mode ?"
+icommands,*imcur,h,"",,,"Image cursor: [x y wcs] key [cmd]"
+gcommands,*gcur,h,"",,,"Graphics cursor: [x y wcs] key [cmd]"
+wcsin,s,h,)_.wcsin,,,"The input coordinate system (logical,tv,physical,world)"
+wcsout,s,h,)_.wcsout,,,"The output coordinate system (logical,tv,physical)"
+cache,b,h,)_.cache,,,"Cache the input image pixels ?"
+verify,b,h,)_.verify,,,"Confirm critical parameters in non-interactive mode ?"
+update,b,h,)_.update,,,"Update critical parameters in non-interactive mode ?"
+verbose,b,h,)_.verbose,,,"Print messages in non-interactive mode ?"
+graphics,s,h,)_.graphics,,,"Graphics device"
+display,s,h,)_.display,,,"Display device"
+mode,s,h,'ql'
diff --git a/noao/digiphot/apphot/wphot/apbwphot.x b/noao/digiphot/apphot/wphot/apbwphot.x
new file mode 100644
index 00000000..b684abb7
--- /dev/null
+++ b/noao/digiphot/apphot/wphot/apbwphot.x
@@ -0,0 +1,108 @@
+include <fset.h>
+include "../lib/apphot.h"
+include "../lib/display.h"
+include "../lib/center.h"
+include "../lib/fitsky.h"
+
+# AP_BWPHOT -- Procedure to compute the magnitudes for a list of objects
+# interactively.
+
+procedure ap_bwphot (ap, im, cl, sd, out, id, ld, gd, mgd, gid, interactive)
+
+pointer ap			# pointer to apphot structure
+pointer	im			# pointer to IRAF image
+int	cl			# starlist file descriptor
+int	sd			# sky file descriptor
+int	out			# output file descriptor
+int	id, ld			# sequence and list numbers
+pointer	gd			# pointer to stdgraph stream
+pointer	mgd			# pointer to the plot metacode stream
+pointer	gid			# pointer to image display stream
+int	interactive		# interactive pr batch mode
+
+int	stdin, ild, cier, sier, pier
+pointer	sp, str
+real	wx, wy
+int	fscan(), nscan(), apfitsky(), apfitcenter(), ap_wmag(), strncmp()
+int	apstati()
+real	apstatr()
+
+begin
+	call smark (sp)
+	call salloc (str, SZ_FNAME, TY_CHAR)
+	call fstats (cl, F_FILENAME, Memc[str], SZ_FNAME)
+
+	# Initialize
+	ild = ld
+
+	# Print query.
+	if (strncmp ("STDIN", Memc[str], 5) == 0)
+	    stdin = YES
+	else
+	    stdin = NO
+	if (stdin == YES) {
+	    call printf ("Type object x and y coordinates (^D or ^Z to end): ")
+	    call flush (STDOUT)
+	}
+
+	# Loop over the coordinate file.
+	while (fscan (cl) != EOF) {
+
+	    # Get and store the coordinates.
+	    call gargr (wx)
+	    call gargr (wy)
+	    if (nscan () != 2) {
+		if (stdin == YES) {
+	    	    call printf (
+		        "Type object x and y coordinates (^D or ^Z to end): ")
+	    	    call flush (STDOUT)
+		}
+		next
+	    }
+
+            # Transform the input coordinates.
+            switch (apstati(ap,WCSIN)) {
+            case WCS_WORLD, WCS_PHYSICAL:
+                call ap_itol (ap, wx, wy, wx, wy, 1)
+            case WCS_TV:
+                call ap_vtol (im, wx, wy, wx, wy, 1)
+            default:
+                ;
+            }
+	    call apsetr (ap, CWX, wx)
+	    call apsetr (ap, CWY, wy)
+
+	    # Center the coordinatess, fit the sky and compute magnitudes.
+	    cier = apfitcenter (ap, im, wx, wy)
+	    sier = apfitsky (ap, im, apstatr (ap, XCENTER), apstatr (ap,
+	        YCENTER), sd, gd)
+	    pier = ap_wmag (ap, im, apstatr (ap, XCENTER), apstatr(ap, YCENTER),
+	        apstati (ap, POSITIVE), apstatr (ap, SKY_MODE),
+		apstatr (ap, SKY_SIGMA), apstati (ap, NSKY))
+
+	    # Write the results.
+	    if (interactive == YES) {
+		call ap_qpmag (ap, cier, sier, pier)
+		if (gid != NULL)
+		    call apmark (ap, gid, apstati (ap, MKCENTER), apstati (ap,
+			MKSKY), apstati (ap, MKAPERT))
+	    }
+	    if (id == 1)
+	        call ap_param (ap, out, "wphot")
+	    call ap_pmag (ap, out, id, ild, cier, sier, pier)
+	    call ap_pplot (ap, im, id, mgd, YES)
+
+	    # Prepare for the next object.
+	    id = id + 1
+	    ild = ild + 1
+	    call apsetr (ap, WX, wx)
+	    call apsetr (ap, WY, wy)
+	    if (stdin == YES) {
+		call printf (
+		    "Type object x and y coordinates (^Z or ^D to end): ")
+		call flush (STDOUT)
+	    }
+	}
+
+	call sfree (sp)
+end
diff --git a/noao/digiphot/apphot/wphot/apgmeasure.x b/noao/digiphot/apphot/wphot/apgmeasure.x
new file mode 100644
index 00000000..738630f2
--- /dev/null
+++ b/noao/digiphot/apphot/wphot/apgmeasure.x
@@ -0,0 +1,190 @@
+# AP_GMEASURE -- Procedure to measure the fluxes and effective areas of a set of
+# apertures assuming a Gaussian weighting function.
+
+procedure ap_gmeasure (im, wx, wy, c1, c2, l1, l2, aperts, sums, areas,
+        naperts, sigsq, gain, varsky)
+
+pointer	im			# pointer to image
+real	wx, wy			# center of subraster
+int	c1, c2			# column limits
+int	l1, l2			# line limits
+real	aperts[ARB]		# array of apertures
+double	sums[ARB]		# array of sums
+double	areas[ARB]		# aperture areas
+int	naperts			# number of apertures
+real	sigsq			# the profile widht squared
+real	gain			# the sky value
+real	varsky			# the sky variance
+
+int	i, j, k, nx, yindex
+double	fctn, weight, norm
+pointer	sp, buf, sump, sumpw
+real	xc, yc, apmaxsq, dy2, r2, r, prof, var
+pointer	imgs2r()
+
+begin
+	# Initialize.
+	call smark (sp)
+	call salloc (sump, naperts, TY_DOUBLE)
+	call salloc (sumpw, naperts, TY_DOUBLE)
+	call aclrd (Memd[sump], naperts)
+	call aclrd (Memd[sumpw], naperts)
+
+	# Get array boundary parameters.
+	nx = c2 - c1 + 1
+	xc = wx - c1 + 1
+	yc = wy - l1 + 1
+	apmaxsq = (aperts[naperts] + 0.5) ** 2
+
+	# Clear out the accumulaters
+	call aclrd (sums, naperts)
+	call aclrd (areas, naperts)
+
+	# Loop over the pixels.
+	do j = l1, l2 {
+	    buf = imgs2r (im, c1, c2, j, j)
+	    if (buf == EOF) {
+		call sfree (sp)
+		return
+	    }
+	    yindex = j - l1 + 1
+	    dy2 = (yindex - yc) ** 2
+	    do i = 1, nx {
+		r2 = (i - xc) ** 2 + dy2
+		if (r2 > apmaxsq)
+		    next
+		prof = max (exp (-r2 / sigsq), 0.0)
+		if (prof <= 0.0)
+		    next
+		var = max (0.0, Memr[buf+i-1])
+		var = var / gain + varsky
+		if (var <= 0.0)
+		    next
+		weight = prof / var
+		r = sqrt (r2) - 0.5
+		do k = 1, naperts {
+		    if (r > aperts[k])
+			next
+		    fctn = max (0.0, min (1.0, aperts[k] - r))
+		    sums[k] = sums[k] + weight * fctn * Memr[buf+i-1]
+		    areas[k] = areas[k] + weight * fctn
+		    Memd[sump+k-1] = Memd[sump+k-1] + prof
+		    Memd[sumpw+k-1] = Memd[sumpw+k-1] + weight * prof
+		}
+	    }
+	}
+
+	# Normalize.
+	do k = 1, naperts {
+	    if (Memd[sumpw+k-1] <= 0.0d0)
+	        norm = 0.0d0
+	    else
+	        norm = Memd[sump+k-1] / Memd[sumpw+k-1]
+	    sums[k] = sums[k] * norm
+	    areas[k] = areas[k] * norm
+	}
+
+	call sfree (sp)
+end
+
+
+# AP_BGMEASURE -- Procedure to measure the fluxes and effective areas of a set
+# of apertures assuming a Gaussian weighting function.
+
+procedure ap_bgmeasure (im, wx, wy, c1, c2, l1, l2, datamin, datamax,
+	aperts, sums, areas, naperts, minapert, sigsq, gain, varsky)
+
+pointer	im			# pointer to image
+real	wx, wy			# center of subraster
+int	c1, c2			# column limits
+int	l1, l2			# line limits
+real	datamin			# minimum good data
+real	datamax			# maximum good data
+real	aperts[ARB]		# array of apertures
+double	sums[ARB]		# array of sums
+double	areas[ARB]		# aperture areas
+int	naperts			# number of apertures
+int	minapert		# minimum aperture fo bad pixels
+real	sigsq			# the profile widht squared
+real	gain			# the image gain value
+real	varsky			# the sky variance
+
+int	i, j, k, nx, yindex, kindex
+double	fctn, weight, norm
+pointer	sp, buf, sump, sumpw
+real	xc, yc, apmaxsq, dy2, r2, r
+real	pixval, prof, var
+pointer	imgs2r()
+
+begin
+	# Initialize.
+	call smark (sp)
+	call salloc (sump, naperts, TY_DOUBLE)
+	call salloc (sumpw, naperts, TY_DOUBLE)
+	call aclrd (Memd[sump], naperts)
+	call aclrd (Memd[sumpw], naperts)
+	minapert = naperts + 1
+
+	# Get array boundary parameters.
+	nx = c2 - c1 + 1
+	xc = wx - c1 + 1
+	yc = wy - l1 + 1
+	apmaxsq = (aperts[naperts] + 0.5) ** 2
+
+	# Clear out the accumulaters
+	call aclrd (sums, naperts)
+	call aclrd (areas, naperts)
+
+	# Loop over the pixels.
+	do j = l1, l2 {
+	    buf = imgs2r (im, c1, c2, j, j)
+	    if (buf == EOF) {
+		call sfree (sp)
+		return
+	    }
+	    yindex = j - l1 + 1
+	    dy2 = (yindex - yc) ** 2
+	    do i = 1, nx {
+		r2 = (i - xc) ** 2 + dy2
+		if (r2 > apmaxsq)
+		    next
+		prof = max (exp (-r2 / sigsq), 0.0)
+		if (prof <= 0.0)
+		    next
+		pixval = Memr[buf+i-1]
+		var = max (0.0, pixval)
+		var = pixval / gain + varsky
+		if (var <= 0.0)
+		    next
+		weight = prof / var
+		r = sqrt (r2) - 0.5
+		kindex = naperts + 1
+		do k = 1, naperts {
+		    if (r > aperts[k])
+			next
+		    kindex = min (k, kindex)
+		    fctn = max (0.0, min (1.0, aperts[k] - r))
+		    sums[k] = sums[k] + weight * fctn * pixval
+		    areas[k] = areas[k] + weight * fctn
+		    Memd[sump+k-1] = Memd[sump+k-1] + prof
+		    Memd[sumpw+k-1] = Memd[sumpw+k-1] + weight * prof
+		}
+		if (kindex < minapert) {
+		    if (pixval < datamin || pixval > datamax)
+			minapert = kindex
+		}
+	    }
+	}
+
+	# Normalize.
+	do k = 1, naperts {
+	    if (Memd[sumpw+k-1] <= 0.0d0)
+	        norm = 0.0d0
+	    else
+	        norm = Memd[sump+k-1] / Memd[sumpw+k-1]
+	    sums[k] = sums[k] * norm
+	    areas[k] = areas[k] * norm
+	}
+
+	call sfree (sp)
+end
diff --git a/noao/digiphot/apphot/wphot/apgwppars.x b/noao/digiphot/apphot/wphot/apgwppars.x
new file mode 100644
index 00000000..91383169
--- /dev/null
+++ b/noao/digiphot/apphot/wphot/apgwppars.x
@@ -0,0 +1,35 @@
+include "../lib/display.h"
+include "../lib/noise.h"
+include "../lib/center.h"
+include "../lib/fitsky.h"
+include "../lib/phot.h"
+
+# AP_GWPPARS -- Procedure to fetch the phot task parameters.
+
+procedure ap_gwppars (ap)
+
+pointer	ap		# pointer to apphot structure
+
+bool	clgetb()
+int	btoi()
+
+begin
+	# Initialize the photometry structure.
+	call appinit (ap, AP_CENTROID1D, 2.5, AP_MODE, 10.0, 10.0, 3.0, 1,
+	    AP_PWCONSTANT, 2.0, AP_NPOISSON)
+
+	# Get the data dependent parameters.
+	call ap_gdapars (ap)
+
+	# Get the centering parameters.
+	call ap_gcepars (ap)
+
+	# Get the sky fitting parameters.
+	call ap_gsapars (ap)
+
+	# Get the photometry parameters.
+	call ap_gwhpars (ap)
+
+	# Set the radplot parameters.
+	call apseti (ap, RADPLOTS, btoi (clgetb ("radplots")))
+end
diff --git a/noao/digiphot/apphot/wphot/aptmeasure.x b/noao/digiphot/apphot/wphot/aptmeasure.x
new file mode 100644
index 00000000..8ba7b650
--- /dev/null
+++ b/noao/digiphot/apphot/wphot/aptmeasure.x
@@ -0,0 +1,192 @@
+# AP_TMEASURE -- Procedure to measure the fluxes and effective areas of a set of
+# apertures assuming a conical weighting function.
+
+procedure ap_tmeasure (im, wx, wy, c1, c2, l1, l2, aperts, sums, areas,
+        naperts, fwhmpsf, gain, varsky)
+
+pointer	im			# pointer to image
+real	wx, wy			# center of subraster
+int	c1, c2			# column limits
+int	l1, l2			# line limits
+real	aperts[ARB]		# array of apertures
+double	sums[ARB]		# array of sums
+double	areas[ARB]		# aperture areas
+int	naperts			# number of apertures
+real	fwhmpsf			# width of the profile
+real	gain			# the image gain
+real	varsky			# the sky variance
+
+int	i, j, k, yindex, nx
+double	fctn, weight, norm
+pointer	buf, sp, sump, sumpw
+real	xc, yc, apmaxsq, dy2, r2, r, pixval, prof, var
+pointer	imgs2r()
+
+begin
+	# Initialize.
+	call smark (sp)
+	call salloc (sump, naperts, TY_DOUBLE)
+	call salloc (sumpw, naperts, TY_DOUBLE)
+	call aclrd (Memd[sump], naperts)
+	call aclrd (Memd[sumpw], naperts)
+
+	# Set up some array boundary parameters.
+	nx = c2 - c1 + 1
+	xc = wx - c1 + 1
+	yc = wy - l1 + 1
+	apmaxsq = (aperts[naperts] + 0.5) ** 2
+
+	# Clear out the accumulaters
+	call aclrd (sums, naperts)
+	call aclrd (areas, naperts)
+
+	# Loop over the pixels.
+	do j = l1, l2 {
+	    buf = imgs2r (im, c1, c2, j, j)
+	    if (buf == NULL) {
+		call sfree (sp)
+		return
+	    }
+	    yindex = j - l1 + 1
+	    dy2 = (yindex - yc) ** 2
+	    do i = 1, nx {
+		r2 = (i - xc) ** 2 + dy2
+		if (r2 > apmaxsq)
+		    next
+		r = sqrt (r2)
+		prof = max (1.0 - r / fwhmpsf, 0.0)
+		if (prof <= 0.0)
+		    next
+		pixval = Memr[buf+i-1]
+		var = max (0.0, pixval)
+		var = var / gain + varsky
+		if (var <= 0.0)
+		    next
+		weight = prof / var
+		r = r - 0.5
+		do k = 1, naperts {
+		    if (r > aperts[k])
+			next
+		    fctn = max (0.0, min (1.0, aperts[k] - r))
+		    Memd[sump+k-1] = Memd[sump+k-1] + prof
+		    Memd[sumpw+k-1] = Memd[sumpw+k-1] + prof * weight
+		    sums[k] = sums[k] + weight * fctn * pixval
+		    areas[k] = areas[k] + weight * fctn
+		}
+	    }
+	}
+
+	# Normalize.
+	do k = 1, naperts {
+	    if (Memd[sumpw+k-1] <= 0.0d0)
+	        norm = 0.0d0
+	    else
+	        norm = Memd[sump+k-1] / Memd[sumpw+k-1]
+	    sums[k] = sums[k] * norm
+	    areas[k] = areas[k] * norm
+	}
+
+	call sfree (sp)
+end
+
+
+# AP_BTMEASURE -- Procedure to measure the fluxes and effective areas of a
+# set of apertures assuming a conical weighting function.
+
+procedure ap_btmeasure (im, wx, wy, c1, c2, l1, l2, datamin, datamax,
+	aperts, sums, areas, naperts, minapert, fwhmpsf, gain, varsky)
+
+pointer	im			# pointer to image
+real	wx, wy			# center of subraster
+int	c1, c2			# column limits
+int	l1, l2			# line limits
+real	datamin			# minimum good data value
+real	datamax			# maximum good data value
+real	aperts[ARB]		# array of apertures
+double	sums[ARB]		# array of sums
+double	areas[ARB]		# aperture areas
+int	naperts			# number of apertures
+int	minapert		# minimum aperture
+real	fwhmpsf			# width of the profile
+real	gain			# the image gain
+real	varsky			# the sky variance
+
+int	i, j, k, yindex, kindex, nx
+double	fctn, weight, norm
+pointer	buf, sp, sump, sumpw
+real	xc, yc, apmaxsq, dy2, r2, r, pixval, prof, var
+pointer	imgs2r()
+
+begin
+	# Initialize.
+	call smark (sp)
+	call salloc (sump, naperts, TY_DOUBLE)
+	call salloc (sumpw, naperts, TY_DOUBLE)
+	call aclrd (Memd[sump], naperts)
+	call aclrd (Memd[sumpw], naperts)
+	minapert = naperts + 1
+
+	# Set up some array boundary parameters.
+	nx = c2 - c1 + 1
+	xc = wx - c1 + 1
+	yc = wy - l1 + 1
+	apmaxsq = (aperts[naperts] + 0.5) ** 2
+
+	# Clear out the accumulaters
+	call aclrd (sums, naperts)
+	call aclrd (areas, naperts)
+
+	# Loop over the pixels.
+	do j = l1, l2 {
+	    buf = imgs2r (im, c1, c2, j, j)
+	    if (buf == NULL) {
+		call sfree (sp)
+		return
+	    }
+	    yindex = j - l1 + 1
+	    dy2 = (yindex - yc) ** 2
+	    do i = 1, nx {
+		r2 = (i - xc) ** 2 + dy2
+		if (r2 > apmaxsq)
+		    next
+		r = sqrt (r2)
+		prof = max (1.0 - r / fwhmpsf, 0.0)
+		if (prof <= 0.0)
+		    next
+		pixval = Memr[buf+i-1]
+		var = max (0.0, pixval)
+		var = var / gain + varsky
+		if (var <= 0.0)
+		    next
+		weight = prof / var
+		r = r - 0.5
+		kindex = naperts + 1
+		do k = 1, naperts {
+		    if (r > aperts[k])
+			next
+		    kindex = min (k, kindex)
+		    fctn = max (0.0, min (1.0, aperts[k] - r))
+		    Memd[sump+k-1] = Memd[sump+k-1] + prof
+		    Memd[sumpw+k-1] = Memd[sumpw+k-1] + prof * weight
+		    sums[k] = sums[k] + weight * fctn * pixval
+		    areas[k] = areas[k] + weight * fctn
+		}
+		if (kindex < minapert) {
+		    if (pixval < datamin || pixval > datamax)
+			minapert = kindex
+		}
+	    }
+	}
+
+	# Normalize.
+	do k = 1, naperts {
+	    if (Memd[sumpw+k-1] <= 0.0d0)
+	        norm = 0.0d0
+	    else
+	        norm = Memd[sump+k-1] / Memd[sumpw+k-1]
+	    sums[k] = sums[k] * norm
+	    areas[k] = areas[k] * norm
+	}
+
+	call sfree (sp)
+end
diff --git a/noao/digiphot/apphot/wphot/apwconfirm.x b/noao/digiphot/apphot/wphot/apwconfirm.x
new file mode 100644
index 00000000..53222388
--- /dev/null
+++ b/noao/digiphot/apphot/wphot/apwconfirm.x
@@ -0,0 +1,110 @@
+include "../lib/apphot.h"
+include "../lib/noise.h"
+include "../lib/center.h"
+include "../lib/fitsky.h"
+include "../lib/phot.h"
+
+# AP_WCONFIRM -- Procedure to confirm the critical phot parameters.
+
+procedure ap_wconfirm (ap, out, stid)
+
+pointer	ap		# pointer to the apphot structure
+int	out		# pointer to the output file descriptor
+int	stid		# output file sequence number
+
+pointer	sp, cstr, sstr, pwstr, aperts
+real	fwhmpsf, capert, annulus, dannulus, skysigma
+real	datamin, datamax
+int	apstati()
+real	apstatr(), ap_vfwhmpsf(), ap_vcapert(), ap_vsigma()
+real	ap_vannulus(), ap_vdannulus(), ap_vdatamin(), ap_vdatamax()
+
+begin
+	call smark (sp)
+	call salloc (cstr, SZ_FNAME, TY_CHAR)
+	call salloc (sstr, SZ_FNAME, TY_CHAR)
+	call salloc (pwstr, SZ_FNAME, TY_CHAR)
+	call salloc (aperts, SZ_LINE, TY_CHAR)
+
+	call printf ("\n")
+
+	# Confirm the centering algorithm.
+	call ap_vcstring (ap, Memc[cstr], SZ_FNAME)
+
+	if (apstati (ap, CENTERFUNCTION) != AP_NONE) {
+
+	    # Confirm the fwhmpsf.
+	    if (apstati (ap, CENTERFUNCTION) != AP_CENTROID1D)
+		fwhmpsf = ap_vfwhmpsf (ap)
+	    else
+	    	fwhmpsf = apstatr (ap, FWHMPSF)
+
+	    # Confirm the centering box.
+	    capert = 2.0 * ap_vcapert (ap)
+
+	} else {
+
+	    fwhmpsf = apstatr (ap, FWHMPSF)
+	    capert = 2.0 * apstatr (ap, CAPERT)
+	}
+
+	# Confirm the sky fitting algorithm.
+	call ap_vsstring (ap, Memc[sstr], SZ_FNAME)
+
+	if (apstati (ap, SKYFUNCTION) != AP_CONSTANT &&
+	    apstati (ap, SKYFUNCTION) != AP_SKYFILE) {
+
+	    # Confirm the sky annulus parameter.
+	    annulus = ap_vannulus (ap)
+
+	    # Confirm the width of the sky annulus.
+	    dannulus = ap_vdannulus (ap)
+
+	} else {
+	    annulus = apstatr (ap, ANNULUS)
+	    dannulus = apstatr (ap, DANNULUS)
+	}
+
+	# Confirm the sky sigma parameter.
+	skysigma = ap_vsigma (ap)
+
+	# Confirm the weighting scheme algorithm.
+	call ap_vpwstring (ap, Memc[pwstr], SZ_FNAME)
+
+	# Confirm the aperture radii parameter.
+	call ap_vaperts (ap, Memc[aperts], SZ_LINE)
+
+	# Verify the datamin and datamax parameters.
+	datamin = ap_vdatamin (ap)
+	datamax = ap_vdatamax (ap)
+
+	call printf ("\n")
+
+	# Update the database file.
+	if (out != NULL && stid > 1) {
+	    call ap_sparam (out, KY_CSTRING, Memc[cstr], UN_CALGORITHM,
+		"centering algorithm")
+	    call ap_rparam (out, KY_FWHMPSF, fwhmpsf, UN_ASCALEUNIT,
+	        "full width half maximum of the psf")
+	    call ap_rparam (out, KY_CAPERT, capert, UN_CSCALEUNIT,
+	        "centering box width")
+	    call ap_sparam (out, KY_SSTRING, Memc[sstr], UN_SALGORITHM,
+		"sky fitting algorithm")
+	    call ap_rparam (out, KY_ANNULUS, annulus, UN_SSCALEUNIT,
+	        "inner radius of the sky annulus")
+	    call ap_rparam (out, KY_DANNULUS, dannulus, UN_SSCALEUNIT,
+	        "width of the sky annulus")
+	    call ap_rparam (out, KY_SKYSIGMA, skysigma, UN_NCOUNTS,
+	        "standard deviation of 1 sky pixel")
+	    call ap_sparam (out, KY_PWSTRING, Memc[pwstr], UN_PMODEL,
+		"photometric weighting function")
+	    call ap_sparam (out, KY_APERTS, Memc[aperts], UN_PSCALEUNIT,
+		"list of apertures")
+	    call ap_rparam (out, KY_DATAMIN, datamin, UN_ACOUNTS,
+	        "minimum good data value")
+	    call ap_rparam (out, KY_DATAMAX, datamax, UN_ACOUNTS,
+	        "maximum good data value")
+	}
+
+	call sfree (sp)
+end
diff --git a/noao/digiphot/apphot/wphot/apwmag.x b/noao/digiphot/apphot/wphot/apwmag.x
new file mode 100644
index 00000000..0818bf3f
--- /dev/null
+++ b/noao/digiphot/apphot/wphot/apwmag.x
@@ -0,0 +1,157 @@
+include <mach.h>
+include "../lib/apphotdef.h"
+include "../lib/apphot.h"
+include "../lib/noisedef.h"
+include "../lib/photdef.h"
+include "../lib/phot.h"
+
+define	CONVERSION	2.772588
+
+# AP_WMAG -- Procedure to compute the magnitudes inside a set of apertures for
+# a single of object.
+
+int procedure ap_wmag (ap, im, wx, wy, positive, skyval, skysig, nsky)
+
+pointer	ap		# pointer to the apphot structure
+pointer	im		# pointer to the IRAF image
+real	wx, wy		# object coordinates
+int	positive	# emission or absorption features
+real	skyval		# sky value
+real	skysig		# sky sigma
+int	nsky		# number of sky pixels
+
+int	c1, c2, l1, l2, ier, nap
+pointer	sp, nse, phot, temp
+real	datamin, datamax, zmag, wsigsq, wvarsky
+int	apmagbuf()
+
+begin
+	# Initalize.
+	phot = AP_PPHOT(ap)
+	nse = AP_NOISE(ap)
+	AP_PXCUR(phot) = wx
+	AP_PYCUR(phot) = wy
+        if (IS_INDEFR(wx) || IS_INDEFR(wy)) {
+            AP_OPXCUR(phot) = INDEFR
+            AP_OPYCUR(phot) = INDEFR
+        } else {
+            switch (AP_WCSOUT(ap)) {
+            case WCS_WORLD, WCS_PHYSICAL:
+                call ap_ltoo (ap, wx, wy, AP_OPXCUR(phot), AP_OPYCUR(phot), 1)
+            case WCS_TV:
+                call ap_ltov (im, wx, wy, AP_OPXCUR(phot), AP_OPYCUR(phot), 1)
+            default:
+                AP_OPXCUR(phot) = wx
+                AP_OPYCUR(phot) = wy
+            }
+        }
+	call amovkd (0.0d0, Memd[AP_SUMS(phot)], AP_NAPERTS(phot))
+	call amovkd (0.0d0, Memd[AP_AREA(phot)], AP_NAPERTS(phot))
+	call amovkr (INDEFR, Memr[AP_MAGS(phot)], AP_NAPERTS(phot))
+	call amovkr (INDEFR, Memr[AP_MAGERRS(phot)], AP_NAPERTS(phot))
+
+	# Make sure the center is defined.
+	if (IS_INDEFR(wx) || IS_INDEFR(wy))
+	    return (AP_APERT_NOAPERT)
+
+	# Fetch the aperture pixels.
+	ier = apmagbuf (ap, im, wx, wy, c1, c2, l1, l2)
+	if (ier == AP_APERT_NOAPERT)
+	    return (AP_APERT_NOAPERT)
+
+	call smark (sp)
+	call salloc (temp, AP_NAPERTS(phot), TY_REAL)
+
+	# Compute the min and max.
+	if (IS_INDEFR(AP_DATAMIN(ap)))
+	    datamin = -MAX_REAL
+	else
+	    datamin = AP_DATAMIN(ap)
+	if (IS_INDEFR(AP_DATAMAX(ap)))
+	    datamax = MAX_REAL
+	else
+	    datamax = AP_DATAMAX(ap)
+
+	# Do photometry for all the apertures.
+	AP_NMINAP(phot) = AP_NMAXAP(phot) + 1
+	call amulkr (Memr[AP_APERTS(phot)], AP_SCALE(ap), Memr[temp],
+	    AP_NAPERTS(phot))
+
+	switch (AP_PWEIGHTS(phot)) {
+	case AP_PWCONSTANT:
+	    if (IS_INDEFR(AP_DATAMIN(ap)) && IS_INDEFR(AP_DATAMAX(ap)))
+	        call  apmeasure (im, wx, wy, c1, c2, l1, l2, Memr[temp],
+	            Memd[AP_SUMS(phot)], Memd[AP_AREA(phot)], AP_NMAXAP(phot))
+	    else
+	        call  apbmeasure (im, wx, wy, c1, c2, l1, l2, datamin,
+		    datamax, Memr[temp], Memd[AP_SUMS(phot)],
+		    Memd[AP_AREA(phot)], AP_NMAXAP(phot), AP_NMINAP(phot))
+	case AP_PWCONE:
+	    wsigsq = AP_FWHMPSF(ap) *  AP_SCALE(ap)
+	    wvarsky = (AP_READNOISE(nse) / AP_EPADU(nse)) ** 2 
+	    if (IS_INDEFR(AP_DATAMIN(ap)) && IS_INDEFR(AP_DATAMAX(ap)))
+	        call  ap_tmeasure (im, wx, wy, c1, c2, l1, l2, Memr[temp],
+	            Memd[AP_SUMS(phot)], Memd[AP_AREA(phot)], AP_NMAXAP(phot),
+		    wsigsq, AP_EPADU(nse), wvarsky)
+	    else
+	        call  ap_btmeasure (im, wx, wy, c1, c2, l1, l2, datamin,
+		    datamax, Memr[temp], Memd[AP_SUMS(phot)],
+		    Memd[AP_AREA(phot)], AP_NMAXAP(phot), AP_NMINAP(phot),
+		    wsigsq, AP_EPADU(nse), wvarsky)
+	case AP_PWGAUSS:
+	    wsigsq = (AP_FWHMPSF(ap) *  AP_SCALE(ap)) ** 2 / CONVERSION
+	    wvarsky = (AP_READNOISE(nse) / AP_EPADU(nse)) ** 2 
+	    if (IS_INDEFR(AP_DATAMIN(ap)) && IS_INDEFR(AP_DATAMAX(ap)))
+	        call  ap_gmeasure (im, wx, wy, c1, c2, l1, l2, Memr[temp],
+	            Memd[AP_SUMS(phot)], Memd[AP_AREA(phot)], AP_NMAXAP(phot),
+		    wsigsq, AP_EPADU(nse), wvarsky)
+	    else
+	        call  ap_bgmeasure (im, wx, wy, c1, c2, l1, l2,
+		    datamin, datamax, Memr[temp], Memd[AP_SUMS(phot)],
+		    Memd[AP_AREA(phot)], AP_NMAXAP(phot), AP_NMINAP(phot),
+		    wsigsq, AP_EPADU(nse), wvarsky)
+	default:
+	    if (IS_INDEFR(AP_DATAMIN(ap)) && IS_INDEFR(AP_DATAMAX(ap)))
+	        call  apmeasure (im, wx, wy, c1, c2, l1, l2, Memr[temp],
+	            Memd[AP_SUMS(phot)], Memd[AP_AREA(phot)], AP_NMAXAP(phot))
+	    else
+	        call  apbmeasure (im, wx, wy, c1, c2, l1, l2, datamin,
+		    datamax, Memr[temp], Memd[AP_SUMS(phot)],
+		    Memd[AP_AREA(phot)], AP_NMAXAP(phot), AP_NMINAP(phot))
+	}
+
+	# Make sure that the sky value has been defined.
+	if (IS_INDEFR(skyval))
+	    ier = AP_APERT_NOSKYMODE
+
+	else {
+
+	    # Check for bad pixels.
+	    if ((ier == AP_OK) && (AP_NMINAP(phot) <= AP_NMAXAP(phot)))
+		ier = AP_APERT_BADDATA
+
+	    nap = min (AP_NMINAP(phot) - 1, AP_NMAXAP(phot))
+
+	    # Compute the magnitudes and errors.
+	    if (positive == YES)
+	        call apcopmags (Memd[AP_SUMS(phot)], Memd[AP_AREA(phot)],
+	            Memr[AP_MAGS(phot)], Memr[AP_MAGERRS(phot)], nap, skyval,
+		    skysig, nsky, AP_ZMAG(phot), AP_NOISEFUNCTION(nse),
+		    AP_EPADU(nse))
+	    else
+	        call apconmags (Memd[AP_SUMS(phot)], Memd[AP_AREA(phot)],
+	            Memr[AP_MAGS(phot)], Memr[AP_MAGERRS(phot)], nap, skyval,
+		    skysig, nsky, AP_ZMAG(phot), AP_NOISEFUNCTION(nse),
+		    AP_EPADU(nse), AP_READNOISE(nse))
+
+	    # Compute correction for itime.
+	    zmag = 2.5 * log10 (AP_ITIME(ap))
+	    call aaddkr (Memr[AP_MAGS(phot)], zmag, Memr[AP_MAGS(phot)], nap)
+	}
+
+	call sfree (sp)
+	if (ier != AP_OK)
+	    return (ier)
+	else
+	    return (AP_OK)
+end
diff --git a/noao/digiphot/apphot/wphot/apwpars.x b/noao/digiphot/apphot/wphot/apwpars.x
new file mode 100644
index 00000000..88406a8f
--- /dev/null
+++ b/noao/digiphot/apphot/wphot/apwpars.x
@@ -0,0 +1,27 @@
+include "../lib/display.h"
+
+# AP_WPARS -- Procedure to write out the wphot task parameters.
+
+procedure ap_wpars (ap)
+
+pointer	ap		# pointer to apphot structure
+
+bool	itob()
+int	apstati()
+
+begin
+	# Write out the data dependent parameters.
+	call ap_dapars (ap)
+
+	# Write the centering parameters.
+	call ap_cepars (ap)
+
+	# Write out the sky fitting parameters.
+	call ap_sapars (ap)
+
+	# Write out the photometry parameters.
+	call ap_phpars (ap)
+
+	# Set the radplots parameter.
+	call clputb ("radplots", itob (apstati (ap, RADPLOTS)))
+end
diff --git a/noao/digiphot/apphot/wphot/apwpcolon.x b/noao/digiphot/apphot/wphot/apwpcolon.x
new file mode 100644
index 00000000..6f6e1f5c
--- /dev/null
+++ b/noao/digiphot/apphot/wphot/apwpcolon.x
@@ -0,0 +1,157 @@
+include <gset.h>
+include "../lib/apphot.h"
+include "../lib/fitsky.h"
+include "../lib/center.h"
+include "../lib/phot.h"
+include "../lib/display.h"
+include "../lib/noise.h"
+
+# AP_WPCOLON -- Process wphot colon commands.
+
+procedure ap_wpcolon (ap, im, cl, out, stid, ltid, cmdstr, newimage,
+	newcenterbuf, newcenter, newskybuf, newsky, newmagbuf, newmag)
+
+pointer	ap				# pointer to the apphot structure
+pointer	im				# pointer to the iraf image
+int	cl				# coord file descriptor
+int	out				# output file descriptor
+int	stid				# output file sequence number
+int	ltid				# coord file  sequence number
+char	cmdstr[ARB]			# command string
+int	newimage			# new image ?
+int	newcenterbuf, newcenter		# new center buffer ? new center fit ?
+int	newskybuf, newsky		# new sky buffer ? new sky fit ?
+int	newmagbuf, newmag		# new aperture buffer ? new fit ?
+
+pointer	sp, incmd, outcmd
+int	strdic()
+
+begin
+	# Get the command.
+	call smark (sp)
+	call salloc (incmd, SZ_LINE, TY_CHAR)
+	call salloc (outcmd, SZ_LINE, TY_CHAR)
+
+	call sscan (cmdstr)
+	call gargwrd (Memc[incmd], SZ_LINE)
+	if (Memc[incmd] == EOS) {
+	    call sfree (sp)
+	    return
+	}
+
+	# Process the command.
+	if (strdic (Memc[incmd], Memc[outcmd], SZ_LINE, CCMDS) != 0)
+	    call apccolon (ap, out, stid, cmdstr, newcenterbuf, newcenter)
+	else if (strdic (Memc[incmd], Memc[outcmd], SZ_LINE, SCMDS) != 0)
+	    call apscolon (ap, out, stid, cmdstr, newskybuf, newsky)
+	else if (strdic (Memc[incmd], Memc[outcmd], SZ_LINE, PCMDS) != 0)
+	    call ap_wmagcolon (ap, out, stid, cmdstr, newmagbuf, newmag)
+	else if (strdic (Memc[incmd], Memc[outcmd], SZ_LINE, APCMDS) != 0)
+	    call ap_apcolon (ap, im, cl, out, stid, ltid, cmdstr, newimage,
+	        newcenterbuf, newcenter, newskybuf, newsky, newmagbuf, newmag)
+	else if (strdic (Memc[incmd], Memc[outcmd], SZ_LINE, NCMDS) != 0)
+	    call ap_nscolon (ap, im, out, stid, cmdstr, newcenterbuf,
+	        newcenter, newskybuf, newsky, newmagbuf, newmag)
+	else
+	    call ap_himcolon (ap, cmdstr)
+
+	call sfree (sp)
+end
+
+
+# AP_WMAGCOLON -- Procedure to display and edit the photometry parameters.
+
+procedure ap_wmagcolon (ap, out, stid, cmdstr, newmagbuf, newmag)
+
+pointer	ap		# pointer to apphot structure
+int	out		# output file descriptor
+int	stid		# output number
+char	cmdstr[ARB]	# command string
+int	newmagbuf	# new aperture buffers
+int	newmag		# compute new magnitudes
+
+bool	bval
+int	ncmd, stat
+pointer	sp, cmd
+real	rval
+bool	itob()
+int	btoi(), strdic(), nscan(), apstati()
+real	apstatr()
+
+begin
+	# Get the command.
+	call smark (sp)
+	call salloc (cmd, SZ_LINE, TY_CHAR)
+	call sscan (cmdstr)
+	call gargwrd (Memc[cmd], SZ_LINE)
+	if (Memc[cmd] == EOS) {
+	    call sfree (sp)
+	    return
+	}
+
+	# Process the command
+	ncmd = strdic (Memc[cmd], Memc[cmd], SZ_LINE, PCMDS)
+	switch (ncmd) {
+	case PCMD_APERTURES:
+	    call gargwrd (Memc[cmd], SZ_LINE)
+	    if (Memc[cmd] == EOS) {
+	        call apstats (ap, APERTS, Memc[cmd], SZ_LINE)
+	        call printf ("%s = %s %s\n")
+		    call pargstr (KY_APERTS)
+		    call pargstr (Memc[cmd])
+		    call pargstr (UN_PSCALEUNIT)
+	    } else {
+		call apsets (ap, APERTS, Memc[cmd])
+		if (stid > 1)
+		    call ap_sparam (out, KY_APERTS, Memc[cmd], UN_PSCALEUNIT,
+			"list of aperture radii")
+		newmag = YES
+		newmagbuf = YES
+	    }
+	case PCMD_ZMAG:
+	    call gargr (rval)
+	    if (nscan() == 1) {
+		call printf ("%s = %g\n")
+		    call pargstr (KY_ZMAG)
+		    call pargr (apstatr (ap, ZMAG))
+	    } else {
+		call apsetr (ap, ZMAG, rval)
+		if (stid > 1)
+		    call ap_rparam (out, KY_ZMAG, rval, UN_PZMAG,
+			"zero point of magnitude scale")
+		newmag = YES
+	    }
+	case PCMD_MKAPERT:
+	    call gargb (bval)
+	    if (nscan () == 1) {
+		call printf ("%s = %b\n")
+		    call pargstr (KY_MKAPERT)
+		    call pargb (itob (apstati (ap, MKAPERT)))
+	    } else {
+		call apseti (ap, MKAPERT, btoi (bval))
+	    }
+	case PCMD_WEIGHTING:
+	    call gargwrd (Memc[cmd], SZ_LINE)
+	    if (Memc[cmd] == EOS) {
+	        call apstats (ap, PWSTRING, Memc[cmd], SZ_LINE)
+	        call printf ("%s = %s\n")
+		    call pargstr (KY_PWSTRING)
+		    call pargstr (Memc[cmd])
+	    } else {
+		stat = strdic (Memc[cmd], Memc[cmd], SZ_LINE, PWFUNCS)
+		if (stat > 0) {
+		    call apseti (ap, PWEIGHTS, stat)
+		    call apsets (ap, PWSTRING, Memc[cmd])
+	   	    if (stid > 1)
+		        call ap_sparam (out, KY_PWSTRING, Memc[cmd],
+			    UN_PMODEL, "photometric weighting model")
+		    newmagbuf = YES
+		    newmag = YES
+		}
+	    }
+	default:
+	    call printf ("Unknown or ambiguous colon command\7\n")
+	}
+
+	call sfree (sp)
+end
diff --git a/noao/digiphot/apphot/wphot/apwphot.x b/noao/digiphot/apphot/wphot/apwphot.x
new file mode 100644
index 00000000..07849c0e
--- /dev/null
+++ b/noao/digiphot/apphot/wphot/apwphot.x
@@ -0,0 +1,509 @@
+include <ctype.h>
+include <gset.h>
+include <imhdr.h>
+include "../lib/phot.h"
+include "../lib/apphot.h"
+include "../lib/display.h"
+include "../lib/center.h"
+include "../lib/fitsky.h"
+
+define	HELPFILE	"apphot$wphot/wphot.key"
+
+# APWPHOT -- Procedure to compute magnitudes for a list of objects
+
+int procedure ap_wphot (ap, im, cl, sd, gd, mgd, id, out, stid, interactive,
+	cache)
+
+pointer ap			# pointer to apphot structure
+pointer	im			# pointer to IRAF image
+int	cl			# starlist file descriptor
+int	sd			# the sky file descriptor
+pointer	gd			# pointer to graphcis descriptor
+pointer	mgd			# pointer to graphics metacode file
+pointer	id			# pointer to image display stream
+int	out			# output file descriptor
+int	stid			# output file sequence number
+int	interactive		# interactive mode
+int	cache			# cache the input image pixels
+
+real	wx, wy, xlist, ylist
+pointer	sp, cmd
+int	wcs, key, ltid, newlist, req_size, old_size, buf_size, memstat
+int	newimage, newskybuf, newsky, newcenterbuf, newcenter, newmagbuf, newmag
+int	colonkey, prev_num, req_num, ip, oid
+int	cier, sier, pier
+
+real	apstatr()
+int	clgcur(), apfitsky(), aprefitsky(), apfitcenter(), aprefitcenter()
+int	ap_wmag(), ap_wremag(), apgscur(), ctoi(), apstati(), apgqverify()
+int	apgtverify(), apnew(), ap_avsky(), ap_memstat(), sizeof()
+bool	fp_equalr()
+
+define  endswitch_ 99
+
+begin
+	# Initialize.
+	call smark (sp)
+	call salloc (cmd, SZ_LINE, TY_CHAR)
+
+	# Initialize the cursor command.
+	key = ' '
+	Memc[cmd] = EOS
+
+	# Initialize the fitting parameters.
+	newimage = NO
+	newcenterbuf = YES; newcenter = YES
+	newskybuf = YES; newsky = YES
+	newmagbuf = YES; newmag = YES
+	cier = AP_OK; sier = AP_OK; pier = AP_OK
+
+	# Initialize the sequence numbering.
+	newlist = NO
+	ltid = 0
+
+	# Loop over the coordinate file.
+	while (clgcur ("icommands", wx, wy, wcs, key, Memc[cmd], SZ_LINE) !=
+	    EOF) {
+
+	    # Store the current cursor coordinates.
+	    call ap_vtol (im, wx, wy, wx, wy, 1)
+	    call apsetr (ap, CWX, wx)
+	    call apsetr (ap, CWY, wy)
+
+	    # Test to see if the cursor moved.
+	    if (apnew (ap, wx, wy, xlist, ylist, newlist) == YES) {
+		newcenterbuf = YES; newcenter = YES
+		newskybuf = YES; newsky = YES
+		newmagbuf = YES; newmag = YES
+	    }
+
+	    # Store previous cursor coordinates.
+	    call apsetr (ap, WX, apstatr (ap, CWX))
+	    call apsetr (ap, WY, apstatr (ap, CWY))
+
+	    # Loop over the colon keystroke commands.
+	    switch (key) {
+
+	    # Quit.
+	    case 'q':
+		if (interactive == YES) {
+		    if (apgqverify ("wphot", ap, key) == YES) {
+			call sfree (sp)
+			return (apgtverify (key))
+		    }
+		} else {
+		    call sfree (sp)
+		    return (NO)
+		}
+
+	    # Print out error messages.
+	    case 'e':
+		if (interactive == YES)
+		    call ap_perrors (ap, cier, sier, pier)
+
+	    # Print out the help page(s).
+	    case '?':
+		if ((id != NULL) && (id == gd))
+		    call gpagefile (id, HELPFILE, "")
+		else if (interactive == YES)
+		    call pagefile (HELPFILE, "[space=morehelp,q=quit,?=help]")
+
+	    # Rewind the list.
+	    case 'r':
+		if (cl != NULL) {
+		    call seek (cl, BOFL)
+		    ltid = 0
+		} else if (interactive == YES)
+		    call printf ("No coordinate list\n")
+
+	    # Get, measure next object from the list.
+	    case 'm', 'n':
+
+                # No coordinate file.
+                if (cl == NULL) {
+                    if (interactive == YES)
+                        call printf ("No coordinate list\n")
+                    goto endswitch_
+
+                }
+
+		# Need to rewind coordinate list.
+		prev_num = ltid
+		req_num = ltid + 1
+		if (apgscur (cl, id, xlist, ylist, prev_num, req_num,
+		    ltid) == EOF) {
+                    if (interactive == YES)
+                        call printf (
+                            "End of coordinate list, use r key to rewind\n")
+                    goto endswitch_
+		}
+
+                # Convert coordinates if necessary.
+                switch (apstati (ap, WCSIN)) {
+                case WCS_PHYSICAL, WCS_WORLD:
+                    call ap_itol (ap,  xlist, ylist, xlist, ylist, 1)
+                case WCS_TV:
+                    call ap_vtol (im, xlist, ylist, xlist, ylist, 1)
+                default:
+                    ;
+                }
+
+		# Move to next object.
+		newlist = YES
+		if (key == 'm') {
+		    newcenterbuf = YES; newcenter = YES
+		    newskybuf = YES; newsky = YES
+		    newmagbuf = YES; newmag = YES
+                    goto endswitch_
+		}
+
+		# Measure the object.
+		cier = apfitcenter (ap, im, xlist, ylist)
+		sier = apfitsky (ap, im, apstatr (ap, XCENTER), apstatr (ap,
+		    YCENTER), sd, gd)
+		pier = ap_wmag (ap, im, apstatr (ap, XCENTER), apstatr (ap,
+		    YCENTER), apstati (ap, POSITIVE), apstatr (ap, SKY_MODE),
+		    apstatr (ap, SKY_SIGMA), apstati (ap, NSKY))
+		if (id != NULL) {
+		    call apmark (ap, id, apstati (ap, MKCENTER), apstati (ap,
+			MKSKY), apstati (ap, MKAPERT))
+		    if (id == gd)
+		        call gflush (id)
+		    else
+		        call gframe (id)
+		}
+		call ap_pplot (ap, im, stid, gd, apstati (ap, RADPLOTS))
+		if (interactive == YES)
+		    call ap_qpmag (ap, cier, sier, pier)
+		if (stid == 1)
+		    call ap_param (ap, out, "wphot")
+		call ap_pmag (ap, out, stid, ltid, cier, sier, pier)
+		call ap_pplot (ap, im, stid, mgd, YES)
+		stid = stid + 1
+		newcenterbuf = NO; newcenter = NO
+		newskybuf = NO; newsky = NO
+		newmagbuf = NO; newmag = NO
+
+	    # Process the remainder of the list.
+	    case 'l':
+		if (cl != NULL) {
+		    oid = stid
+		    ltid = ltid + 1
+		    call ap_bwphot (ap, im, cl, sd, out, stid, ltid, gd, mgd,
+		        id, YES)
+		    ltid = ltid + stid - oid + 1
+		    if (id != NULL) {
+		        if (id == gd)
+			    call gflush (id)
+		        else
+			    call gframe (id)
+		    }
+		} else if (interactive == YES)
+		    call printf ("No coordinate list\n")
+
+	    # Process apphot colon commands.
+	    case ':':
+		for (ip = 1; IS_WHITE(Memc[cmd+ip-1]); ip = ip + 1)
+		    ;
+		colonkey = Memc[cmd+ip-1]
+		switch (colonkey) {
+		case 'm', 'n':
+
+		    # Show/set a wphot parameter.
+		    if (Memc[cmd+ip] != EOS && Memc[cmd+ip] != ' ') {
+		        call ap_wpcolon (ap, im, cl, out, stid, ltid, Memc[cmd],
+			    newimage, newcenterbuf, newcenter, newskybuf,
+			    newsky, newmagbuf, newmag)
+			goto endswitch_
+		    }
+
+		    # No coordinate list.
+		    if (cl == NULL) {
+                        if (interactive == YES)
+                            call printf ("No coordinate list\n")
+                        goto endswitch_
+
+		    }
+
+		    # Get next object from list.
+		    ip = ip + 1
+		    prev_num = ltid
+		    if (ctoi (Memc[cmd], ip, req_num) <= 0)
+		        req_num = ltid + 1
+
+		    # Fetch the next object from the list.
+		    if (apgscur (cl, id, xlist, ylist, prev_num, req_num,
+			ltid) == EOF) {
+                        if (interactive == YES)
+                            call printf (
+                            "End of coordinate list, use r key to rewind\n")
+                        goto endswitch_
+
+		    }
+
+                    # Convert the coordinates.
+                    switch (apstati (ap, WCSIN)) {
+                    case WCS_PHYSICAL, WCS_WORLD:
+                        call ap_itol (ap,  xlist, ylist, xlist, ylist, 1)
+                    case WCS_TV:
+                        call ap_vtol (im, xlist, ylist, xlist, ylist, 1)
+                    default:
+                        ;
+                    }
+
+		    # Move to the next object.
+		    newlist = YES
+		    if (colonkey == 'm') {
+		    	newcenterbuf = YES; newcenter = YES
+		    	newskybuf = YES; newsky = YES
+		    	newmagbuf = YES; newmag = YES
+                        goto endswitch_
+		    }
+
+		    # Measure the next object.
+		    cier = apfitcenter (ap, im, xlist, ylist)
+		    sier = apfitsky (ap, im, apstatr (ap, XCENTER),
+			apstatr (ap, YCENTER), sd, gd)
+		    pier = ap_wmag (ap, im, apstatr (ap, XCENTER), apstatr (ap,
+		        YCENTER), apstati (ap, POSITIVE), apstatr (ap,
+			SKY_MODE), apstatr (ap, SKY_SIGMA), apstati (ap, NSKY))
+		    if (id != NULL) {
+			call apmark (ap, id, apstati (ap, MKCENTER),
+			    apstati (ap, MKSKY), apstati (ap, MKAPERT))
+			if (id == gd)
+			    call gflush (id)
+			else
+			    call gframe (id)
+		    }
+		    call ap_pplot (ap, im, stid, gd, apstati (ap, RADPLOTS))
+		    if (interactive == YES)
+		         call ap_qpmag (ap, cier, sier, pier)
+		    if (stid == 1)
+		        call ap_param (ap, out, "wphot")
+		    call ap_pmag (ap, out, stid, ltid, cier, sier, pier)
+		    call ap_pplot (ap, im, stid, mgd, YES)
+		    stid = stid + 1
+		    newcenterbuf = NO; newcenter = NO
+		    newskybuf = NO; newsky = NO
+		    newmagbuf = NO; newmag = NO
+
+		# Show/set a phot parameter.
+		default:
+		    call ap_wpcolon (ap, im, cl, out, stid, ltid, Memc[cmd],
+		        newimage, newcenterbuf, newcenter, newskybuf, newsky,
+			newmagbuf, newmag)
+		}
+
+		# Reestablish the image viewport and window.
+		if (newimage == YES) {
+		    if ((id != NULL) && (id != gd))
+		        call ap_gswv (id, Memc[cmd], im, 4)
+                    req_size = MEMFUDGE * IM_LEN(im,1) * IM_LEN(im,2) *
+                        sizeof (IM_PIXTYPE(im))
+                    memstat = ap_memstat (cache, req_size, old_size)
+                    if (memstat == YES)
+                        call ap_pcache (im, INDEFI, buf_size)
+		}
+
+		newimage = NO
+
+	    # Save the current parameters in the pset files.
+	    case 'w':
+		call ap_wpars (ap)
+
+	    # Plot centered radial profile.
+	    case 'd':
+		if (interactive == YES) {
+		    call ap_qrad (ap, im, wx, wy, gd)
+		    newmagbuf = YES; newmag = YES
+		    newcenterbuf = YES; newcenter = YES
+		    newskybuf = YES; newsky = YES
+		}
+
+	    # Setup phot parameters interactively.
+	    case 'i':
+		if (interactive == YES) {
+		    call ap_radsetup (ap, im, wx, wy, gd, out, stid)
+		    newmagbuf = YES; newmag = YES
+		    newcenterbuf = YES; newcenter = YES
+		    newskybuf = YES; newsky = YES
+		}
+
+	    # Verify critical parameters.
+	    case 'v':
+		call ap_wconfirm (ap, out, stid)
+		newmagbuf = YES; newmag = YES
+		newcenterbuf = YES; newcenter = YES
+		newskybuf = YES; newsky = YES
+
+	     # Fit the center around the cursor position.
+	     case 'c':
+		if (newcenterbuf == YES)
+		    cier = apfitcenter (ap, im, wx, wy)
+		else if (newcenter == YES)
+		    cier = aprefitcenter (ap, im, cier)
+		if (id != NULL) {
+		    call apmark (ap, id, apstati (ap, MKCENTER), NO, NO)
+		    if (id == gd)
+			call gflush (id)
+		    else
+			call gframe (id)
+		}
+		call ap_cplot (ap, stid, gd, apstati (ap, RADPLOTS))
+		if (interactive == YES)
+		    call ap_qcenter (ap,  cier)
+		newcenterbuf = NO; newcenter = NO
+
+	    # Fit the sky around the cursor position.
+	    case 't':
+	        if (newskybuf == YES || ! fp_equalr (wx,
+		    apstatr (ap, SXCUR)) || ! fp_equalr (wy, apstatr (ap,
+		    SYCUR)))
+		    sier = apfitsky (ap, im, wx, wy, sd, gd)
+	        else if (newsky == YES)
+		    sier = aprefitsky (ap, im, gd)
+		if (id != NULL) {
+		    call apmark (ap, id, NO, apstati (ap, MKSKY), NO)
+		    if (id == gd)
+			call gflush (id)
+		    else
+			call gframe (id)
+		}
+		call ap_splot (ap, stid, gd, apstati (ap, RADPLOTS))
+		if (interactive == YES)
+		    call ap_qspsky (ap, sier)
+		newskybuf = NO; newsky = NO
+
+	    # Compute the average of several sky measurements around
+            # different cursor postions.
+            case 'a':
+                sier = ap_avsky (ap, im, stid, sd, id, gd, interactive)
+                if (interactive == YES)
+                    call ap_qaspsky (ap, sier)
+                newskybuf = NO; newsky = NO
+
+	     # Fit the sky around the current center position. 
+	     case 's':
+	        if (newskybuf == YES || ! fp_equalr (apstatr (ap, XCENTER),
+		    apstatr (ap, SXCUR)) || ! fp_equalr (apstatr (ap, SYCUR),
+		    apstatr (ap, YCENTER)))
+		    sier = apfitsky (ap, im, apstatr (ap, XCENTER),
+		        apstatr (ap, YCENTER), sd, gd)
+		else if (newsky == YES)
+		    sier = aprefitsky (ap, im, gd)
+		if (id != NULL) {
+		    call apmark (ap, id, NO, apstati (ap, MKSKY), NO)
+		    if (id == gd)
+			call gflush (id)
+		    else
+			call gframe (id)
+		}
+		call ap_splot (ap, stid, gd, apstati (ap, RADPLOTS))
+		if (interactive == YES)
+		    call ap_qspsky (ap, sier)
+		newskybuf = NO; newsky = NO
+
+	    # Compute magnitudes around the cursor position using the current
+	    # sky.
+	    case 'p':
+		if (newcenterbuf == YES)
+		    cier = apfitcenter (ap, im, wx, wy)
+		else if (newcenter == YES)
+		    cier = aprefitcenter (ap, im, cier)
+	        if (newmagbuf == YES || ! fp_equalr (apstatr (ap, XCENTER),
+		    apstatr (ap, PXCUR)) || ! fp_equalr (apstatr (ap,
+		    PYCUR), apstatr (ap, YCENTER)))
+		    pier = ap_wmag (ap, im, apstatr (ap, XCENTER),
+		        apstatr (ap, YCENTER), apstati (ap, POSITIVE),
+		        apstatr (ap, SKY_MODE), apstatr (ap, SKY_SIGMA),
+		        apstati (ap, NSKY))
+		else
+		    pier = ap_wremag (ap, im, apstati (ap, POSITIVE),
+		        apstatr (ap, SKY_MODE), apstatr (ap, SKY_SIGMA),
+			apstati (ap, NSKY))
+		if (id != NULL) {
+		    call apmark (ap, id, NO, NO, apstati (ap, MKAPERT))
+		    if (id == gd)
+			call gflush (id)
+		    else
+			call gframe (id)
+		}
+		if (interactive == YES)
+		    call ap_qpmag (ap, cier, sier, pier)
+		newcenterbuf = NO; newcenter = NO
+		newmagbuf = NO; newmag = NO
+		if (key == 'o') {
+		    if (stid == 1)
+		        call ap_param (ap, out, "wphot")
+		    if (newlist == YES)
+		        call ap_pmag (ap, out, stid, ltid, cier, sier, pier)
+		    else
+		        call ap_pmag (ap, out, stid, 0, cier, sier, pier)
+		    call ap_pplot (ap, im, stid, mgd, YES)
+		    stid = stid + 1
+		}
+
+	    # Compute the center, sky, and magnitudes and save the results.
+	    case 'f', ' ':
+		if (newcenterbuf == YES)
+		    cier = apfitcenter (ap, im, wx, wy)
+		else if (newcenter == YES)
+		    cier = aprefitcenter (ap, im, cier)
+		if (newskybuf == YES || ! fp_equalr (apstatr (ap, XCENTER),
+		    apstatr (ap, SXCUR)) || ! fp_equalr (apstatr (ap, YCENTER),
+		    apstatr (ap, SYCUR)))
+		    sier = apfitsky (ap, im, apstatr (ap, XCENTER), apstatr (ap,
+		        YCENTER), sd, gd)
+		else if (newsky == YES)
+		    sier = aprefitsky (ap, im, gd)
+		if (newmagbuf == YES || ! fp_equalr (apstatr (ap, XCENTER),
+		    apstatr (ap, PXCUR)) || ! fp_equalr (apstatr (ap, YCENTER),
+		    apstatr (ap, PYCUR)))
+		    pier = ap_wmag (ap, im, apstatr (ap, XCENTER),
+		        apstatr (ap, YCENTER), apstati (ap, POSITIVE),
+			apstatr (ap, SKY_MODE), apstatr (ap, SKY_SIGMA),
+			apstati (ap, NSKY))
+		else
+		    pier = ap_wremag (ap, im, apstati (ap, POSITIVE),
+		        apstatr (ap, SKY_MODE), apstatr (ap, SKY_SIGMA),
+			apstati (ap, NSKY))
+
+		if (id != NULL) {
+		    call apmark (ap, id, apstati (ap, MKCENTER), apstati (ap,
+		        MKSKY), apstati (ap, MKAPERT))
+		    if (id == gd)
+			call gflush (id)
+		    else
+			call gframe (id)
+		}
+		call ap_pplot (ap, im, stid, gd, apstati (ap, RADPLOTS))
+		if (interactive == YES)
+		    call ap_qpmag (ap, cier, sier, pier)
+
+		newcenterbuf = NO; newcenter = NO
+		newskybuf = NO; newsky = NO
+		newmagbuf = NO; newmag = NO
+
+		if (key == ' ') {
+		    if (stid == 1)
+		        call ap_param (ap, out, "wphot")
+		    if (newlist == YES)
+		        call ap_pmag (ap, out, stid, ltid, cier, sier, pier)
+		    else
+		        call ap_pmag (ap, out, stid, 0, cier, sier, pier)
+		    call ap_pplot (ap, im, stid, mgd, YES)
+		    stid = stid + 1
+		}
+
+	    default:
+		call printf ("Unknown or ambiguous keystroke command\n")
+	    }
+
+endswitch_
+	    # Setup for the next object.
+	    key = ' '
+	    Memc[cmd] = EOS
+	}
+
+	call sfree (sp)
+end
diff --git a/noao/digiphot/apphot/wphot/apwremag.x b/noao/digiphot/apphot/wphot/apwremag.x
new file mode 100644
index 00000000..5f611ec8
--- /dev/null
+++ b/noao/digiphot/apphot/wphot/apwremag.x
@@ -0,0 +1,76 @@
+include <mach.h>
+include "../lib/apphotdef.h"
+include "../lib/apphot.h"
+include "../lib/noisedef.h"
+include "../lib/photdef.h"
+include "../lib/phot.h"
+
+# AP_WREMAG -- Procedure to recompute the magnitudes inside a set of apertures
+# given that the sums and effective areas have already been computed.
+
+int procedure ap_wremag (ap, im, positive, skyval, skysig, nsky)
+
+pointer	ap		# pointer to the apphot structure
+pointer	im		# the input image descriptor
+int	positive	# emission or absorption features
+real	skyval		# sky value
+real	skysig		# sigma of sky
+int	nsky		# number of sky pixels
+
+int	nap
+pointer	nse, phot
+real	zmag
+
+begin
+	# Initalize.
+	phot = AP_PPHOT(ap)
+	nse = AP_NOISE(ap)
+	call amovkr (INDEFR, Memr[AP_MAGS(phot)], AP_NAPERTS(phot))
+	call amovkr (INDEFR, Memr[AP_MAGERRS(phot)], AP_NAPERTS(phot))
+        if (IS_INDEFR(AP_PXCUR(phot)) || IS_INDEFR(AP_PYCUR(phot))) {
+            AP_OPXCUR(phot) = AP_PXCUR(phot)
+            AP_OPYCUR(phot) = AP_PYCUR(phot)
+        } else {
+            switch (AP_WCSOUT(ap)) {
+            case WCS_WORLD, WCS_PHYSICAL:
+                call ap_ltoo (ap, AP_PXCUR(phot), AP_PYCUR(phot),
+                    AP_OPXCUR(phot), AP_OPYCUR(phot), 1)
+            case WCS_TV:
+                call ap_ltov (im, AP_PXCUR(phot), AP_PYCUR(phot),
+                    AP_OPXCUR(phot), AP_OPYCUR(phot), 1)
+            default:
+                AP_OPXCUR(phot) = AP_PXCUR(phot)
+                AP_OPYCUR(phot) = AP_PYCUR(phot)
+            }
+        }
+
+	if (IS_INDEFR(AP_PXCUR(phot)) || IS_INDEFR(AP_PYCUR(phot)))
+	    return (AP_APERT_NOAPERT)
+	if (IS_INDEFR(skyval))
+	    return (AP_APERT_NOSKYMODE)
+
+	nap = min (AP_NMINAP(phot) - 1, AP_NMAXAP(phot))
+
+	# Compute the magnitudes and errors.
+	if (positive == YES)
+	    call apcopmags (Memd[AP_SUMS(phot)], Memd[AP_AREA(phot)],
+	        Memr[AP_MAGS(phot)], Memr[AP_MAGERRS(phot)], nap,
+	        skyval, skysig, nsky, AP_ZMAG(phot), AP_NOISEFUNCTION(nse),
+		AP_EPADU(nse))
+	else
+	    call apconmags (Memd[AP_SUMS(phot)], Memd[AP_AREA(phot)],
+	        Memr[AP_MAGS(phot)], Memr[AP_MAGERRS(phot)], nap,
+	        skyval, skysig, nsky, AP_ZMAG(phot), AP_NOISEFUNCTION(nse),
+		AP_EPADU(nse), AP_READNOISE(nse))
+
+	# Correct for itime.
+	zmag = 2.5 * log10 (AP_ITIME(ap))
+	call aaddkr (Memr[AP_MAGS(phot)], zmag, Memr[AP_MAGS(phot)], nap)
+
+	if (AP_NMINAP(phot) <= AP_NMAXAP(phot))
+	    return (AP_APERT_BADDATA)
+	else if (AP_NMAXAP(phot) < AP_NAPERTS(phot))
+	    return (AP_APERT_OUTOFBOUNDS)
+	else
+	    return (AP_OK)
+end
diff --git a/noao/digiphot/apphot/wphot/mkpkg b/noao/digiphot/apphot/wphot/mkpkg
new file mode 100644
index 00000000..ac69a00d
--- /dev/null
+++ b/noao/digiphot/apphot/wphot/mkpkg
@@ -0,0 +1,38 @@
+# WPHOT task
+
+$checkout libpkg.a ".."
+$update libpkg.a
+$checkin libpkg.a ".."
+$exit
+
+libpkg.a:
+	apbwphot.x	<fset.h>		../lib/apphot.h        \
+			../lib/center.h		../lib/display.h       \
+			../lib/fitsky.h
+	apgwppars.x	../lib/center.h		../lib/fitsky.h        \
+			../lib/phot.h		../lib/display.h       \
+			../lib/noise.h
+	apwconfirm.x	../lib/apphot.h		../lib/noise.h         \
+			../lib/center.h		../lib/fitsky.h	       \
+			../lib/phot.h
+	apwmag.x	<mach.h>		../lib/apphotdef.h     \
+			../lib/noisedef.h	../lib/photdef.h       \
+			../lib/apphot.h         ../lib/phot.h
+	apgmeasure.x	
+	aptmeasure.x
+	apwpars.x	../lib/display.h
+	apwphot.x	<ctype.h>		<gset.h>               \
+			../lib/apphot.h		../lib/display.h       \
+			../lib/center.h		../lib/fitsky.h        \
+			../lib/phot.h		<imhdr.h>
+	apwpcolon.x	../lib/noise.h		../lib/apphot.h        \
+			../lib/display.h	../lib/fitsky.h        \
+			../lib/center.h		../lib/phot.h          \
+			<gset.h>
+	apwremag.x	<mach.h>		../lib/apphotdef.h     \
+			../lib/noisedef.h       ../lib/photdef.h       \
+			../lib/apphot.h         ../lib/phot.h
+	t_wphot.x	<fset.h>		<gset.h>	       \
+			<lexnum.h>		../lib/apphot.h        \
+			../lib/fitsky.h		<imhdr.h>
+	;
diff --git a/noao/digiphot/apphot/wphot/t_wphot.x b/noao/digiphot/apphot/wphot/t_wphot.x
new file mode 100644
index 00000000..14a82a3e
--- /dev/null
+++ b/noao/digiphot/apphot/wphot/t_wphot.x
@@ -0,0 +1,339 @@
+include <fset.h>
+include <gset.h>
+include <lexnum.h>
+include <imhdr.h>
+include "../lib/apphot.h"
+include "../lib/fitsky.h"
+
+# T_WPHOT -- Procedure to measure magnitudes inside a set of apertures for a
+# list of stars in a list of images.
+
+procedure t_wphot ()
+
+pointer	image		# pointer to name of the image
+pointer output		# pointer to output file name
+pointer coords		# pointer to name of coords file
+pointer	skyfile		# pointer to name of file with sky values
+pointer	plotfile	# pointer to name of plot metacode file
+pointer graphics	# pointer to graphics display device
+pointer	display		# pointer to display device
+int	interactive	# mode of use
+int	cache		# cache the input image pixels
+int	verify		# verify critical parameters
+int	update		# update the critical parameters
+int	verbose		# print messages in verbose mode
+
+pointer	sp, outfname, cname, ap, im, gd, mgd, id, str
+int	limlist, lclist, lolist, lslist, sid, lid, sd, out, cl, root, stat, pfd
+int	imlist, clist, olist, slist, wcs, memstat, req_size, old_size, buf_size
+
+pointer	immap(), gopen()
+int	imtlen(), imtgetim(), clplen(), clgfil(), btoi(), apstati(), clgwrd()
+int	strncmp(), strlen(), fnldir(), ap_wphot(), imtopenp(), clpopnu(), open()
+int	ap_memstat(), sizeof()
+bool	clgetb(), streq()
+errchk	gopen
+
+begin
+	# Allocate temporary space.
+	call smark (sp)
+	call salloc (image, SZ_FNAME, TY_CHAR)
+	call salloc (output, SZ_FNAME, TY_CHAR)
+	call salloc (coords, SZ_FNAME, TY_CHAR)
+	call salloc (skyfile, SZ_FNAME, TY_CHAR)
+	call salloc (plotfile, SZ_FNAME, TY_CHAR)
+	call salloc (graphics, SZ_FNAME, TY_CHAR)
+	call salloc (display, SZ_FNAME, TY_CHAR)
+	call salloc (outfname, SZ_FNAME, TY_CHAR)
+	call salloc (cname, SZ_FNAME, TY_CHAR)
+	call salloc (str, SZ_LINE, TY_CHAR)
+
+	# Set the standard output to flush on newline.
+	call fseti (STDOUT, F_FLUSHNL, YES)
+
+	# Get the task parameters.
+	imlist = imtopenp ("image")
+	limlist = imtlen (imlist)
+	clist = clpopnu ("coords")
+	lclist = clplen (clist)
+	olist = clpopnu ("output")
+	lolist = clplen (olist)
+
+	# Check that image and coordinate list lengths match.
+	if (limlist < 1 || (lclist > 1 && lclist != limlist)) {
+	    call imtclose (imlist)
+	    call clpcls (clist)
+	    call clpcls (olist)
+	    call error (0, "Imcompatible image and coordinate list lengths")
+	}
+
+	# Check that image and output list lengths match.
+	if (lolist > 1 && lolist != limlist) {
+	    call imtclose (imlist)
+	    call clpcls (clist)
+	    call clpcls (olist)
+	    call error (0, "Imcompatible image and output list lengths")
+	}
+
+	call clgstr ("icommands.p_filename", Memc[cname], SZ_FNAME)
+	if (Memc[cname] != EOS)
+	    interactive = NO
+	#else if (lclist == 0)
+	    #interactive = YES
+	else
+	    interactive = btoi (clgetb ("interactive"))
+	cache = btoi (clgetb ("cache"))
+	verify = btoi (clgetb ("verify"))
+	update = btoi (clgetb ("update"))
+	verbose = btoi (clgetb ("verbose"))
+
+	# Intialize the phot structure.
+	call ap_gwppars (ap)
+
+	# Confirm the algorithm parameters.
+	if (verify == YES && interactive == NO) {
+	    call ap_wconfirm (ap, NULL, 1)
+	    if (update == YES)
+		call ap_wpars (ap)
+	}
+
+        # Get the wcs information.
+        wcs = clgwrd ("wcsin", Memc[str], SZ_LINE, WCSINSTR)
+        if (wcs <= 0) {
+            call eprintf (
+                "Warning: Setting the input coordinate system to logical\n")
+            wcs = WCS_LOGICAL
+        }
+        call apseti (ap, WCSIN, wcs)
+        wcs = clgwrd ("wcsout", Memc[str], SZ_LINE, WCSOUTSTR)
+        if (wcs <= 0) {
+            call eprintf (
+                "Warning: Setting the output coordinate system to logical\n")
+            wcs = WCS_LOGICAL
+        }
+        call apseti (ap, WCSOUT, wcs)
+
+	# Get the graphics and display devices.
+	call clgstr ("graphics", Memc[graphics], SZ_FNAME)
+	call clgstr ("display", Memc[display], SZ_FNAME)
+
+	# Open the plot files.
+	if (interactive == YES) {
+	    if (Memc[graphics] == EOS)
+		gd = NULL
+	    else {
+		iferr {
+		    gd = gopen (Memc[graphics], APPEND+AW_DEFER, STDGRAPH)
+		} then {
+		    call eprintf (
+			"Warning: Error opening graphics device.\n")
+		    gd = NULL
+		}
+	    }
+	    if (Memc[display] == EOS)
+		id = NULL
+	    else if (streq (Memc[graphics], Memc[display]))
+		id = gd
+	    else {
+		iferr {
+		    id = gopen (Memc[display], APPEND, STDIMAGE)
+		} then {
+		    call eprintf (
+		"Warning: Graphics overlay not available for display device.\n")
+		    id = NULL
+		}
+	    }
+	} else {
+	    gd = NULL
+	    id = NULL
+	}
+
+	# Open the plot metacode file.
+	call clgstr ("plotfile", Memc[plotfile], SZ_FNAME)
+	if (Memc[plotfile] == EOS)
+	    pfd = NULL
+	else
+	    pfd = open (Memc[plotfile], APPEND, BINARY_FILE)
+	if (pfd != NULL)
+	    mgd = gopen (Memc[graphics], NEW_FILE, pfd)
+	else
+	    mgd = NULL
+
+	# Get the file name for the sky values.
+	if (apstati (ap, SKYFUNCTION) == AP_SKYFILE) {
+	    slist = clpopnu ("skyfile")
+	    lslist = clplen (slist)
+	    if (limlist < 1 || (lslist > 1 && lslist != limlist)) {
+	        call imtclose (imlist)
+	        call clpcls (clist)
+	        call clpcls (olist)
+		call clpcls (slist)
+	        call error (0, "Imcompatible image and sky file list lengths")
+	    }
+	} else
+	    sd = NULL
+
+	# Begin looping over the image list.
+	sid = 1
+	while (imtgetim (imlist, Memc[image], SZ_FNAME) != EOF) {
+
+	    # Open the image and store image parameters.
+	    im = immap (Memc[image], READ_ONLY, 0)
+	    call apimkeys (ap, im, Memc[image])
+
+	    # Set the image display viewport.
+	    if ((id != NULL) && (id != gd))
+		call ap_gswv (id, Memc[image], im, 4)
+
+	    # Cache the input image pixels.
+            req_size = MEMFUDGE * IM_LEN(im,1) * IM_LEN(im,2) *
+                sizeof (IM_PIXTYPE(im))
+            memstat = ap_memstat (cache, req_size, old_size)
+            if (memstat == YES)
+                call ap_pcache (im, INDEFI, buf_size)
+
+	    # Open the coordinate file, where coords is assumed to be a simple
+	    # text file in which the x and y positions are in columns 1 and 2
+	    # respectively and all remaining fields are ignored.
+
+	    if (lclist <= 0) {
+		cl = NULL
+		call strcpy ("", Memc[outfname], SZ_FNAME)
+	    } else {
+		stat = clgfil (clist, Memc[coords], SZ_FNAME)
+		root = fnldir (Memc[coords], Memc[outfname], SZ_FNAME)
+		if (strncmp ("default", Memc[coords+root], 7) == 0 || root ==
+		    strlen (Memc[coords])) {
+		    call ap_inname (Memc[image], Memc[outfname], "coo",
+		        Memc[outfname], SZ_FNAME)
+		    lclist = limlist
+	            cl = open (Memc[outfname], READ_ONLY, TEXT_FILE)
+		} else if (stat != EOF) {
+		    call strcpy (Memc[coords], Memc[outfname], SZ_FNAME)
+	            cl = open (Memc[outfname], READ_ONLY, TEXT_FILE)
+		} else {
+		    call apstats (ap, CLNAME, Memc[outfname], SZ_FNAME)
+		    call seek (cl, BOF)
+		}
+	    }
+	    call apsets (ap, CLNAME, Memc[outfname])
+	    call apfroot (Memc[outfname], Memc[str], SZ_LINE)
+	    call apsets (ap, CLROOT, Memc[str])
+
+	    # Open the skys file.
+	    if (lslist <= 0) {
+		sd = NULL
+		call strcpy ("", Memc[skyfile], SZ_FNAME)
+	    } else if (clgfil (slist, Memc[skyfile], SZ_FNAME) != EOF)
+		sd = open (Memc[skyfile], READ_ONLY, TEXT_FILE)
+	    else
+		call seek (sd, BOF)
+	    #call apsets (ap, SKYNAME, Memc[skyfile])
+
+	    # Open the output text file, if output is "default", dir$default
+	    # or a directory specification then the extension "mag" is added
+	    # to the image name and a suitable version number is appended to
+	    # the output name. If the output name is null then no output
+	    # file is created.
+
+	    if (lolist == 0) {
+		out = NULL
+		call strcpy ("", Memc[outfname], SZ_FNAME)
+	    } else {
+	        stat = clgfil (olist, Memc[output], SZ_FNAME)
+		root = fnldir (Memc[output], Memc[outfname], SZ_FNAME)
+		if (strncmp ("default", Memc[output+root], 7) == 0 || root ==
+		    strlen (Memc[output])) {
+		    call apoutname (Memc[image], Memc[outfname], "omag",
+		        Memc[outfname], SZ_FNAME)
+		    out = open (Memc[outfname], NEW_FILE, TEXT_FILE)
+		    lolist = limlist 
+		} else if (stat != EOF) {
+		    call strcpy (Memc[output], Memc[outfname], SZ_FNAME)
+		    out = open (Memc[outfname], NEW_FILE, TEXT_FILE)
+		} else
+		    call apstats (ap, OUTNAME, Memc[outfname], SZ_FNAME)
+	    }
+	    call apsets (ap, OUTNAME, Memc[outfname])
+
+	    # Do aperture photometry.
+	    if (interactive == NO) {
+	        if (Memc[cname] != EOS)
+		    stat = ap_wphot (ap, im, cl, sd, NULL, mgd, NULL, out,
+		        sid, NO, cache)
+	        else if (cl != NULL) {
+		    lid = 1
+	            call ap_bwphot (ap, im, cl, sd, out, sid, lid, gd, mgd, id,
+		        verbose)
+		    stat = NO
+		} else 
+		    stat = NO
+	    } else
+		stat = ap_wphot (ap, im, cl, sd, gd, mgd, id, out, sid, YES,
+		    cache)
+
+	    # Cleanup.
+	    call imunmap (im)
+	    if (cl != NULL) {
+		if (lclist > 1)
+		    call close (cl)
+	    }
+	    if (sd != NULL) {
+		if (lslist > 1)
+		    call close (sd)
+	    }
+	    if (out != NULL && lolist != 1) {
+		call close (out)
+		if (sid <= 1) {
+		    call apstats (ap, OUTNAME, Memc[outfname], SZ_FNAME)
+		    call delete (Memc[outfname])
+		}
+		sid = 1
+	    }
+
+	    # Uncache memory.
+	    call fixmem (old_size)
+
+	    if (stat == YES)
+		break
+	}
+
+
+	# Close the coordinate, sky and output files.
+	if (cl != NULL && lclist == 1)
+	    call close (cl)
+	if (sd != NULL && lslist == 1)
+	    call close (sd)
+	if (out != NULL && lolist == 1) {
+	    call close (out)
+	    if (sid <= 1) {
+		call apstats (ap, OUTNAME, Memc[outfname], SZ_FNAME)
+		call delete (Memc[outfname])
+	    }
+	}
+
+	# Close up plot files
+	if (id == gd && id != NULL)
+	    call gclose (id)
+	else {
+	    if (gd != NULL)
+	          call gclose (gd)
+	    if (id != NULL)
+	        call gclose (id)
+	}
+	if (mgd != NULL)
+	    call gclose (mgd)
+	if (pfd != NULL)
+	    call close (pfd)
+
+	# Free the photometry structures.
+	call appfree (ap)
+
+	# Close the coord, sky and image lists.
+	call imtclose (imlist)
+	call clpcls (clist)
+	if (sd != NULL)
+	    call clpcls (slist)
+	call clpcls (olist)
+	call sfree (sp)
+end
diff --git a/noao/digiphot/apphot/wphot/wphot.key b/noao/digiphot/apphot/wphot/wphot.key
new file mode 100644
index 00000000..808bf923
--- /dev/null
+++ b/noao/digiphot/apphot/wphot/wphot.key
@@ -0,0 +1,109 @@
+	Interactive Photometry Commands
+
+?	Print help
+:	Colon commands
+v	Verify the critical parameters
+w	Store the current parameters
+d	Plot radial profile of current star 
+i	Interactively set parameters using current star
+c	Fit center of current star
+t	Fit sky around cursor
+a       Average sky values fit around several cursor positions
+s	Fit sky around the current star
+p	Do photometry for current star, using current sky
+o	Do photometry for current star, using current sky, output results
+f	Do photometry for current star
+spbar	Do photometry for current star, output results
+m	Move to next star in coordinate list
+n	Do photometry for next star in coordinate list, output results
+l	Do photometry for remaining stars in coordinate list, output results
+r	Rewind the coordinate list
+e	Print error messages
+q	Exit task
+
+
+	Colon Commands
+
+:show	[data/center/sky/fit]	Show parameters
+:m [n]	Move to next [nth] star in the coordinate list
+:n [n]	Do photometry for next [nth] star in coordinate list, output results
+
+
+	Colon Parameter Editing Commands
+
+# Image and file parameters
+
+:image		[string]	Image name
+:coords		[string]	Coordinate file name
+:output		[string]	Output file name
+
+# Data dependent parameters
+
+:scale		[value]		Image scale (units per pixel)
+:fwhmpsf	[value]		Full-width half-maximum of PSF (scale units)
+:emission	[y/n]		Emission features (y), absorption (n)
+:sigma	        [value]		Standard deviation of sky (counts)
+:datamin	[value]		Minimum good pixel value (counts)
+:datamax	[value]		Maximum good pixel value (counts)
+
+# Noise parameters
+
+:noise		[string]	Noise model (constant|poisson)
+:gain		[string]	Gain image header keyword
+:ccdread	[string]	Readout noise image header keyword
+:epadu		[value]		Gain (electrons  per adu)
+:readnoise	[value]		Readout noise (electrons)
+
+# Observations parameters
+
+:exposure	[string]	Exposure time image header keyword
+:airmass	[string]	Airmass image header keyword
+:filter		[string]	Filter image header keyword
+:obstime	[string]	Time of observation image header keyword
+:itime 		[value]		Integration time (time units)
+:xairmass	[value]		Airmass value (number)
+:ifilter	[string]	Filter id string
+:otime		[string]	Time of observations (time units)
+
+# Centering algorithm parameters
+
+:calgorithm	[string]	Centering algorithm
+:cbox		[value]		Width of the centering box (scale units)
+:cthreshold	[value]		Centering intensity threshold (sigma)
+:cmaxiter	[value]		Maximum number of iterations
+:maxshift	[value]		Maximum center shift (scale units)
+:minsnratio	[value]		Minimum S/N ratio for centering
+:clean		[y/n]		Clean subraster before centering
+:rclean		[value]		Cleaning radius (scale units)
+:rclip		[value]		Clipping radius (scale units)
+:kclean		[value]		Clean K-sigma rejection limit (sigma)
+
+# Sky fitting algorithm parameters
+
+:salgorithm	[string]	Sky fitting algorithm
+:skyvalue	[value]		User supplied sky value (counts)
+:annulus	[value]		Inner radius of sky annulus (scale units)
+:dannulus	[value]		Width of sky annulus (scale units)
+:khist		[value]		Sky histogram extent (+/- sigma)
+:binsize	[value]		Resolution of sky histogram (sigma)
+:smooth		[y/n]		Lucy smooth the sky histogram
+:sloclip	[value]		Low-side clipping factor in percent
+:shiclip	[value]		High-side clipping factor in percent
+:smaxiter	[value]		Maximum number of iterations
+:snreject	[value]		Maximum number of rejection cycles
+:sloreject	[value]		Low-side pixel rejection limits (sky sigma)
+:shireject	[value]		High-side pixel rejection limits (sky sigma)
+:rgrow		[value]		Region growing radius (scale units)
+
+# Photometry parameters
+
+:weighting	[string]	Weighting function (constant|cone|gauss)
+:apertures	[string]	List of aperture radii (scale units)
+:zmag		[value]		Zero point of magnitude scale
+
+# Plotting and marking parameters
+
+:mkcenter	[y/n]		Mark computed centers on display
+:mksky		[y/n]		Mark the sky annuli on the display
+:mkapert	[y/n]		Mark apertures on the display
+:radplot	[y/n]		Plot radial profile of object
diff --git a/noao/digiphot/apphot/x_apphot.x b/noao/digiphot/apphot/x_apphot.x
new file mode 100644
index 00000000..33c73ed1
--- /dev/null
+++ b/noao/digiphot/apphot/x_apphot.x
@@ -0,0 +1,12 @@
+# Task statements for the apphot package
+
+task center    = t_center,
+     daofind   = t_daofind,
+     fitpsf    = t_fitpsf,
+     fitsky    = t_fitsky,
+     wphot     = t_wphot,
+     phot      = t_phot,
+     polymark  = t_polymark,
+     polyphot  = t_polyphot,
+     qphot     = t_qphot,
+     radprof   = t_radprof