iraf.net

NUMBER:	402
MODULE:	reidentify
SYSTEM:	V2.11-V2.11.1
DATE:	Mon Jun  1 10:08:25 MST 1998
FROM:	valdes

BUG:	When using REIDENTIFY to trace spatial positions in long slit data
	for distortion calibration, an incorrect shift is used when
	switching from tracing in decreasing line/column numbers to tracing
	in increasing numbers.  The shift used is that between the
	reference point and the lowest line/column and it is applied to the
	next increasing point from the reference position.  If this shift
	is significant then this can cause the features to either fail to
	be found or to have the wrong features found.

	Normally for long slit distortion calibration in the initial
	identifications of features to trace (with IDENTIFY) no function is
	fit between the measured positions and the reference positions
	(which are usually the same as the measured positions).  By fitting
	a function the problem will be avoided.  Any function will do since
	FITCOORDS later fits its own function and the IDENTIFY/REIDENTIFY
	function is never used.

STATUS:	This is fixed for future releases.