iraf.net

NUMBER:	214
MODULE:	scopy, sarith
SYSTEM:	V2.10-V2.10.2
DATE:	Thu May 20 17:07:53 MST 1993
FROM:	valdes

BUG:	When using SCOPY or SARITH with a specified wavelength range,
	w1 and w2 not equal to INDEF, and rebin=yes the spectra are
	correctly resampled to the requested wavelength interval but
	the coordinate system in the header is updated incorrectly.
	The coordinates may be off by a fraction of a pixel.  For
	example if w1=6400 and w2=6600 the output data will have
	the first pixel at 6400 but the coordinate reported by
	LISPIXEL or any other task might be 6400.25 (where the
	dispersion is, say, 3 Angstroms per pixel).  This error
	is caused during the conversion from logical to physical
	pixel coordinates when the physical coordinates are treated
	as integer; i.e. a wavelength of 6400 for the first logical
	pixel might be physical pixel 185.325 but it is then
	truncated to 185 and the coordinate system is set so
	that physical pixel 185 is 6400 and pixel 185.325 is
	6400.25.  This is a subtle error which may be discovered
	by looking at the coordinate of the first pixel with LISTPIX
	and comparing it with the requested wavelength of the first pixel.

STATUS:	Fixed in V2.10.3.

NUMBER:	356
MODULE:	splot
SYSTEM:	V2.10.4 (including p1 and p2)
DATE:	Tue Dec  3 12:02:39 MST 1996
FROM:	valdes

BUG:	Any units string in the 'units' parameter that contains whitespace,
	such as 'km/s 400 ang' 'inv cm', will fail to be recognized.  This
	is because the whitespace is removed to check for a null string.
	This means such units cannot be specified for SPLOT to start up
	with.  The work around is to change the units interactively
	with :units.

STATUS:	Fixed for the next release.

NUMBER:	400
MODULE:	scopy, sarith
SYSTEM:	V2.10-V2.11.1
DATE:	Fri Apr 17 16:04:13 MST 1998
FROM:	valdes

BUG:	When using SCOPY or SARITH with rebin=yes on spectra which have
	non-linear dispersion functions the resulting spectra will have
	an incorrect dispersion function.  The problem is the dispersion
	function will be linear but the dispersion type value is still
	set to non-linear.  Attempting to use this spectrum will cause
	an error, such as a segmentation violation, because the software
	will look for the non-linear dispersion coefficients which do
	not exist.  One may use rebin=no to extract a desired wavelength
	range without rebinning the spectra or use DISPCOR to resample
	the spectra to a specific dispersion range.

STATUS:	Fixed for the next patch or release.

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.

NUMBER:	469
MODULE:	specplot
SYSTEM:	-V2.11.3p1
DATE:	Mon Aug 14 11:01:13 MST 2000
FROM:	valdes

BUG:	You cannot specify units using the 'units' parameter that consist
	of more than one word.  For example 'log angstroms', 'inv
	centimeter', or 'km/s 4000 ang' will not work.  There is no error
	message and instead the default display units (the 'units_display'
	attribute in the WAT keywords) are used.  The units can be set
	interactively with the ':units' colon command.  If you want to get
	such units running SPECPLOT non-interactively the only workaround
	is to set the 'units_display' attribute.  This can be done either
	with careful header editing (HEDIT or HFIX) or by displaying with
	SPLOT, setting the units, and then writing out the spectrum.

STATUS:	Fixed in future releases.