iraf.net

NUMBER:	308
MODULE:	artdata.mkobjects
SYSTEM:	V2.9-V2.10.4
DATE:	Mon Aug 14 09:55:27 MST 1995
FROM:	valdes

BUG:	When using an image either as a PSF model or as an object
	model the result is very subtly wrong in the fluxes.
	The problem showed up when using a symmetrical PSF model
	and the resulting star or galaxy profile was not symmetric
	at a low level.  The measured centroid was off by 0-0.05
	pixels.  This is caused by a numerical precision error
	that occasionally adds an extra subpixel to the flux
	computed for an output pixel.  There is no workaround
	though the effect can be minimized by using a larger
	number of subpixels.  However, the effect is very small
	and simulations with added noise would likely swamp the
	error.

STATUS:	Fixed in later versions.

NUMBER:	393
MODULE:	rv.fxcor
SYSTEM:	V2.11.1
DATE:	Tue Feb 17 14:57:11 MST 1998
FROM:	fitz

BUG:	When computing a deblended fit to the correlation peak the task
	may trigger a 'floating overflow' exception when quitting the
	deblending routine.

STATUS:	The bug occurs only when the velocities for each component cannot
	be computes and are returned as INDEF values.  Starting with V2.11
	the double-precision value of INDEF was changed to 10e308 and will
	cause an overflow when it's converted to real when saving values in
	the task structure.  A code change is required to fix this.  As a
	workaround be sure that all necessary keywords are in the image
	header prior to the correlation so velocities can be computed.  A
	list of missing keywords is printed in the verbose output listing
	generated by the 'v' keystroke when the 'verbose' parameter is
	'long' or 'txtonly', use the initial fit of a single function to
	get these keywords prior to deblending.

	Fixed for the next release.