Driver procedure (for SUBSTAR) to subtract scaled PSF values
Computes residuals of the PSF fitting program
T_SUBSTAR, image, fitsfile, id,[ psfname, /VERBOSE, /NOPSF ]
IMAGE - On input, IMAGE is the original image array. A scaled
PSF will be subtracted from IMAGE at specified star positions.
Make a copy of IMAGE before calling SUBSTAR, if you want to
keep a copy of the unsubtracted image array
FITSFILE - scalar string giving the name of the disk FITS ASCII
produced as an output from T_NSTAR.
ID - Index vector indicating which stars are to be subtracted. If
omitted, (or set equal to -1), then stars will be subtracted
at all positions specified by the X and Y vectors.
(IDL convention - zero-based subscripts)
PSFNAME - Name of the FITS file containing the PSF residuals, as
generated by GETPSF. SUBSTAR will prompt for this parameter
if not supplied.
Optional Input Keyword
/VERBOSE - If this keyword is set and non-zero, then the value of each
star number will be displayed as it is processed.
/NOPSF - if this keyword is set and non-zero, then all stars will be
be subtracted *except* those used to determine the PSF.
An improved PSF can then be derived from the subtracted image.
If NOPSF is supplied, then the ID parameter is ignored
T_SUBSTAR does not modify the input FITS table.
FTGET(), FTINFO, READFITS(), REMOVE, SUBSTAR
Written, R. Hill, ST Sys. Corp., 22 August 1991
Added NOPSF keyword W. Landsman March, 1996
Use FITS format for PSF resduals July, 1997
Converted to IDL V5.0 W. Landsman September 1997
Call FTINFO first to improve efficiency W. Landsman May 2000