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