helplog.6: longslit fitcoords transform fceval

Frank Valdes wrote on Jan 06, 2005

NUMBER:	6
KEYWORDS:	longslit fitcoords transform fceval
DATE:	Thu Jan  6 12:44:12 MST 2005
FROM:	valdes

Q:	I would like to generate a mapping from (x,y) pixels of an image
	to a wavelength and a spatial axis coordinate.  I know this is
	what TRANSFORM through the FITCOORDS database.  Can I do the
	evaluation directly from the CL?  I found that the IRAF math
	libraries include routines for evaluating the FITSCOORDS mappings
	but I can't find a CL interface for them.  Is there a way to use
	the math routines to evaluate the FITCOORDS mappings?

A:	You are in luck because a task to do what you want was added to
	V2.12.2 (and following patches).  So if you have the latest IRAF
	then the task you want is LONGSLIT.FCEVAL.

	As far as accessing the functions in the math package these are
	purely for SPP programming.  In future there will be language
	bindings for access from other languages but it will still be
	largely intended for software developers rather than users.  While
	it might be an interesting idea to wrap these functions into CL
	callable tasks it might not be so useful depending on how the input
	is defined.  Anyway, this is a low priority at this time.  We do
	welcome suggestions such as the one that led to FCEVAL which was
	basically similar to your request.

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Last post on Jan 06, 2005