[fitsbits] Re: [fitswcs] WCSLIB 3.3

[Mark Calabretta]

On Wed 2003/10/22 11:38:28 MST, Stephen Walton wrote
in a message to: fitsbits at cv.nrao.edu

>Mark's announcement of WCSLIB 3.3 reminds me to ask a generic question
>about an issue I'm sure others have faced:  how best to switch from an
>IRAF environment to a CFITSIO/WCSLIB one.  While IRAF has served us well
>for 15 years, I don't see a huge effort being undertaken to bring its
>WCS library in compliance with the standard, nor to support other map

IRAF was one of the first packages to adopt WCSLIB, and I received a lot
of useful feedback from Lindsay Davis on the earliest versions.  However,
not being an IRAF user myself, I don't know what its current status is.

The current plan regarding CFITSIO and WCSLIB is for Bill Pence to write
a CFITSIO function which extracts the header into a char array, and for
me to write a WCSLIB function which identifies and extracts all WCS
cards from the header and returns an array of pointers to wcsprm structs
(an array because the header could contain secondary WCS).  Users will
be able to call one, then the other, and then feed the chosen wcsprm
struct to their favourite (or even their favorite) WCSLIB routine.

Initially only primary headers and image extensions will be handled, but
later versions will also do pixel lists and BINTABLES, the latter being
somewhat trickier to implement.  Hopefully these routines should appear
before too long.

Mark Calabretta
ATNF