iraf.net

NUMBER:	323
MODULE:	scopy, sarith
SYSTEM:	V2.10 - V2.10.4
DATE:	Mon Jan 22 15:06:10 MST 1996
FROM:	valdes

BUG:	When using SCOPY or SARITH with a wavelength range specified
	in the reverse sense of the data and without rebinning a
	segmentation error occurs.  By reverse sense this means if the
	spectra have decreasing wavelength with increasing pixel then the
	limits are specified with the starting pixel less than the ending
	pixel (or vice-versa). The task resamples any and all associated
	spectra such as the sky and sigma spectra.  However, in this
	particular case it was applied without checking whether such
	spectra exist which cause the memory access error.  The workaround
	is to specify the limits in the same sense as the dispersion if the
	direction really doesn't matter or to flip the spectrum with an
	image section.  An example of the last case for a 1D spectrum would
	be:

		cl> scopy spec1[-*] spec2 w1=3600 w2=5600 rebin=no

	where spec1 has decreasing wavelength with increasing pixel.


STATUS:	Fixed in the next release.