	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
