iraf.net

NUMBER:	210
MODULE:	photcal.mknobsfile,photcal.mkobsfile,photcal.obsfile
SYSTEM:	V2.10
DATE:	Fri Apr  2 11:45:11 MST 1993
FROM:	davis

BUG:	The mknobsfile,mkobsfile, and obsfile task were occasionally dropping
	stars from the output observations file in the case that: 1) the
	parameter allfilters=no, 2) there were multiple matches to a
	given star in 1 or more filters, and 3) the closet matching star was
	not the first candidate star found.

	This bug was occuring because the code was correctly matching to
	the nearest of the possible candidate stars, but was not resetting
	the matching index from the previous star, confusing the indexing
	scheme, and causing the incorrectly matched star to be dropped
	from the list.

STATUS:	The bug is fixed in 2.10.3. There is no fullproof workaround but
	accurately determining the shifts between frames and using small
	matching tolerances will minimize the problem.


NUMBER:	463
MODULE:	splot
SYSTEM:	V2.11-V2.11.3a
DATE:	Tue Feb 15 15:59:39 MST 2000
FROM:	valdes

BUG:	The 'h' key method for measuring equivalent widths will produce
	an arithmetic exception (such as divide by zero) when the pixel
	coordinate becomes large (say > 4000).  The exact error and limit
	value depends on the host system.  The workaround is to extract the
	desired piece of the spectrum into a shorter piece.  If you know
	the pixel coordinates you could use IMCOPY with an image section.
	If you know the wavelength region then use SCOPY.

	    on> imcopy longspec[5210:5310] temp
		or
	    on> scopy longspec temp w1=6140 w2=6143 rebin-

	    on> splot temp
	    

	Alternatively one can use one of the other methods for measuring
	equivalent widths such as 'e', 'k', or 'd'.

STATUS:	The algorithm is revised in the next release.