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author | Joe Hunkeler <jhunkeler@gmail.com> | 2015-08-11 16:51:37 -0400 |
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committer | Joe Hunkeler <jhunkeler@gmail.com> | 2015-08-11 16:51:37 -0400 |
commit | 40e5a5811c6ffce9b0974e93cdd927cbcf60c157 (patch) | |
tree | 4464880c571602d54f6ae114729bf62a89518057 /noao/twodspec/apextract/doc/aprecenter.hlp | |
download | iraf-osx-40e5a5811c6ffce9b0974e93cdd927cbcf60c157.tar.gz |
Repatch (from linux) of OSX IRAF
Diffstat (limited to 'noao/twodspec/apextract/doc/aprecenter.hlp')
-rw-r--r-- | noao/twodspec/apextract/doc/aprecenter.hlp | 148 |
1 files changed, 148 insertions, 0 deletions
diff --git a/noao/twodspec/apextract/doc/aprecenter.hlp b/noao/twodspec/apextract/doc/aprecenter.hlp new file mode 100644 index 00000000..5a05cb36 --- /dev/null +++ b/noao/twodspec/apextract/doc/aprecenter.hlp @@ -0,0 +1,148 @@ +.help aprecenter Sep96 noao.twodspec.apextract +.ih +NAME +aprecenter -- Recenter apertures automatically +.ih +USAGE +aprecenter input +.ih +PARAMETERS +.ls input +List of input images in which apertures are to be recentered. +.le +.ls apertures = "" +Apertures to recenter, resize, trace, and extract. This only applies +to apertures read from the input or reference database. Any new +apertures defined with the automatic finding algorithm or interactively +are always selected. The syntax is a list comma separated ranges +where a range can be a single aperture number, a hyphen separated +range of aperture numbers, or a range with a step specified by "x<step>"; +for example, "1,3-5,9-12x2". +.le +.ls references = "" +List of reference images to be used to define apertures for the input +images. When a reference image is given it supersedes apertures +previously defined for the input image. The list may be null, "", or +any number of images less than or equal to the list of input images. +There are three special words which may be used in place of an image +name. The word "last" refers to the last set of apertures written to +the database. The word "OLD" requires that an entry exist +and the word "NEW" requires that the entry not exist for each input image. +.le +.ls interactive = no +Run this task interactively? If the task is not run interactively then +all user queries are suppressed and interactive aperture editing is +disabled. +.le +.ls find = yes +Find the spectra and define apertures automatically? In order for +spectra to be found automatically there must be no apertures for the +input image or reference image defined in the database. +.le +.ls recenter = yes +Recenter the apertures? +.le +.ls resize = no +Resize the apertures? +.le +.ls edit = yes +Edit the apertures? The \fIinteractive\fR parameter must also be yes. +.le + +.ls line = INDEF +The dispersion line (line or column perpendicular to the dispersion axis) to +be used in recentering the spectra. A value of INDEF selects the middle of the +image. +.le +.ls nsum = 1 +Number of dispersion lines to be summed or medianed. The lines are taken +around the specified dispersion line. A positive value takes a sum +and a negative values selects a median. +.le +.ls aprecenter = "" +List of apertures to be used in shift calculation. +.le +.ls npeaks = INDEF +Select the specified number of apertures with the highest peak values +to be recentered. If the number is INDEF all apertures will be selected. +If the value is less than 1 then the value is interpreted as a fraction +of total number of apertures. +.le +.ls shift = yes +Use the median shift from recentering the selected apertures to apply to +all apertures. The recentering is then a constant shift for all apertures. +The median is the average of the two central values for an even number +of apertures. +.le +.ih +ADDITIONAL PARAMETERS +I/O parameters and the default dispersion axis are taken from the +package parameters, the default aperture parameters are taken from the +task \fBapdefault\fR, automatic aperture finding parameters are taken +from \fBapfind\fR, and parameters used for centering and editing the +apertures are taken from \fBapedit\fR. + +When this operation is performed from the task \fBapall\fR all parameters +except the package parameters are included in that task. +.ih +DESCRIPTION +For each image in the input image list, the aperture center positions +are redefined by centering at the specified dispersion line using the +\fBcenter1d\fR algorithm with centering parameters from \fBapedit\fR. +Normally this is done when inheriting apertures from an aperture +reference image. The recentering does not change the "trace" of the +aperture but simple adds a shift across the dispersion axis. + +There are a several recentering options. Each selected aperture may be +recentered independently. However, if some or all of the spectra are +relatively weak this may actually be worse than using the reference +apertures defined by strong spectra or flat fields in the case of +fibers or aperture masks. One may select a subset of apertures to be +used in calculating shift. This is done with a the \fIaprecenter\fR +list of aperture numbers (see +\fBranges\fR for the syntax) and/or by selecting a specific number or +fraction of the apertures with the strongest peak values. The list +selection is done first and the strongest remaining apertures are used +to satisfy the \fBnpeaks\fR value. Though some or all of the apertures +may be recentered independently the most common case of recentering +reference apertures is to account for detector shifts. In this case +one expects that any shift should be common to all apertures. The +\fIshift\fR parameter allows using the new centers for all selected +apertures to compute a median shift to be added to ALL apertures. Using +a median shift for all apertures is the default. + +The \fIfind\fR parameter allows automatically finding apertures if none +are defined for the image or by a reference image. Since the purpose +of this task is to recenter reference apertures it is usually the case +that reference images are used and apertures are not defined by this +task. One case in which the apertures from the image itself might be +recentered is if one wants to use a different dispersion line. The +\fIresize\fR parameter may be used to adjust the widths in a variety +of ways based on the spectra profiles specific to each image. The +aperture positions and any other parameters may also be edited with the +aperture editing function if selected by the \fIapedit\fR parameter and +the task is run interactively. The recentering algorithm may be run +from the aperture editor using the 'g' keystroke. + +If the task is interactive the user is queried whether to perform +various steps on each image. The queries may be answered with one of +the four values "yes", "no", "YES" and "NO", where an upper case +response suppresses all further queries to this question. + +The aperture recentering algorithm may be selected from nearly every task +in the package. +.ih +EXAMPLES + cl> aprecenter newimage reference=flat +.ih +REVISIONS +.ls APRECENTER V2.11 +The "apertures" parameter can be used to select apertures for resizing, +recentering, tracing, and extraction. This parameter name was previously +used for selecting apertures in the recentering algorithm. The new +parameter name for this is now "aprecenter". +.le +.ih +SEE ALSO +center1d, ranges, apfind, apresize, apedit, apall +.endhelp |