A Space & astronomy forum. SpaceBanter.com

Go Back   Home » SpaceBanter.com forum » Astronomy and Astrophysics » FITS
Site Map Home Authors List Search Today's Posts Mark Forums Read Web Partners

[fitsbits] [fitswcs] WCSLIB 3.3



 
 
Thread Tools Display Modes
  #1  
Old October 23rd 03, 07:19 AM
Mark Calabretta
external usenet poster
 
Posts: n/a
Default [fitsbits] [fitswcs] WCSLIB 3.3


On Wed 2003/10/22 11:38:28 MST, Stephen Walton wrote
in a message to:

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


  #2  
Old October 23rd 03, 04:48 PM
Doug Mink
external usenet poster
 
Posts: n/a
Default [fitsbits] [fitswcs] WCSLIB 3.3

Stephen Walton wrote:

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
projections beyond those already in place. As a solar astronomer I have
other needs :-) .

Most of my code is in Fortran, with just a few SPP "wrapper" main
programs to get access to some of the IRAF IMIO routines.


My WCSTools package supports all of Mark's projections (though I am still
in the process of upgrading it from WCSLIB 2.9 to WCSLIB 3.3) and reads
IRAF imh files as well as FITS files. I support the IRAF TNX projection,
but haven't quite got around to implementing the IRAF ZPX projection.
There are Fortran wrapper for the WCS subroutines, too. WCSTools has
its own FITS code--I've been dealing with FITS for over 20 years--but
the WCS subroutines are easily separated from the rest and are currently
used by CFITSIO, as well as many of the popular astronomical image display
programs. I am continuing to make an effort to support the evolving
standard as well as legacy WCS formats, including most drafts of the
FITS WCS papers. Multiple (and even chained) WCS's are supported, and
I have starting implementing FITS-WCS Paper IV by providing distortion
correction for SIRTF images.

Documentation and source code are available at

http://tdc-www.harvard.edu/software/wcstools/

-Doug Mink
Telescope Data Center
Smithsonian Astrophysical Observatory
Cambridge, Massachusetts USA

  #3  
Old October 23rd 03, 04:56 PM
David Berry
external usenet poster
 
Posts: n/a
Default [fitsbits] [fitswcs] WCSLIB 3.3



On Wed, 22 Oct 2003, Stephen Walton wrote:

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
projections beyond those already in place. As a solar astronomer I have
other needs :-) .

Most of my code is in Fortran, with just a few SPP "wrapper" main
programs to get access to some of the IRAF IMIO routines.


You may be interested in the AST library which provides a high level
interface for reading, writing, modifying and plotting generalised WCS
information (including FITS-WCS of various flavours). It is callable
from Fortran, C and (via JNI) from Java. See:

http://www.starlink.ac.uk/ast/

David

  #4  
Old October 24th 03, 07:53 PM
Stephen Walton
external usenet poster
 
Posts: n/a
Default [fitsbits] [fitswcs] WCSLIB 3.3

On Thu, 2003-10-23 at 08:48, Doug Mink wrote:

My WCSTools package supports all of Mark's projections (though I am still
in the process of upgrading it from WCSLIB 2.9 to WCSLIB 3.3) and reads
IRAF imh files as well as FITS files.


Thanks for taking the time to answer, Doug. I do have one question:
when you say WCSTools "reads IRAF imh files" does that mean it works
with both the PC and CD matrix formalisms?
--
Stephen Walton
Dept. of Physics & Astronomy, Cal State Northridge

  #5  
Old October 24th 03, 07:55 PM
Stephen Walton
external usenet poster
 
Posts: n/a
Default [fitsbits] [fitswcs] WCSLIB 3.3

On Wed, 2003-10-22 at 23:19, Mark Calabretta wrote:

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


This sounds really excellent. As someone who has a lot of images in the
CD matrix format, though, may I politely request that Bill and/or your
routines support the CD and PC matrices?

Thanks much for all your work!
--
Stephen Walton
Dept. of Physics & Astronomy, Cal State Northridge

  #6  
Old October 27th 03, 12:17 AM
Mark Calabretta
external usenet poster
 
Posts: n/a
Default [fitsbits] [fitswcs] WCSLIB 3.3


On Fri 2003/10/24 11:55:37 MST, Stephen Walton wrote
in a message to: Mark Calabretta
and copied to:

CD matrix format, though, may I politely request that Bill and/or your
routines support the CD and PC matrices?


WCSLIB already does, as of version 3.0, and also recognizes CROTAn
in old header files. Likewise for the new parsing routine that I
mentioned (when it eventually appears).

Cheers, Mark


  #7  
Old October 27th 03, 05:56 PM
Doug Mink
external usenet poster
 
Posts: n/a
Default [fitsbits] [fitswcs] WCSLIB 3.3

Stephen Walton wrote:

On Thu, 2003-10-23 at 08:48, Doug Mink wrote:

My WCSTools package supports all of Mark's projections (though I am still
in the process of upgrading it from WCSLIB 2.9 to WCSLIB 3.3) and reads
IRAF imh files as well as FITS files.


Thanks for taking the time to answer, Doug. I do have one question:
when you say WCSTools "reads IRAF imh files" does that mean it works
with both the PC and CD matrix formalisms?


WCSTools supports both PCi_j and CDi_j matrix formalisms, as well as the
PC00i00j keywords which were in some of the early drafts of the FITS WCS
papers. The order of preference, if for some reason multiple formalisms
are present is CDi_j, PC00i00j, PCi_j, and finally CDELTi/CROTAi. If
CTYPEi is not present, DSS keywords are checked; if they are not present,
a non-rotated north-up, east-left TAN projection centered at RA,DEC at the
center of the image, with a scale in arcseconds per pixel specified by any
of several commonly used variations on SECPIX is initialized.

WCSTools can read IRAF imh files created on any computer (IRAF characters
in headers in old imh files are two byes and hence endian like the data in
either of the two imh formats.

-Doug Mink
Telescope Data Center
Smithsonian Astrophysical Observatory
Cambridge, Massachusetts USA

  #8  
Old October 29th 03, 10:09 AM
David Berry
external usenet poster
 
Posts: n/a
Default [fitsbits] [fitswcs] WCSLIB 3.3


On Fri 2003/10/24 11:55:37 MST, Stephen Walton wrote
in a message to: Mark Calabretta
and copied to:

CD matrix format, though, may I politely request that Bill and/or your
routines support the CD and PC matrices?


WCSLIB already does, as of version 3.0, and also recognizes CROTAn
in old header files. Likewise for the new parsing routine that I
mentioned (when it eventually appears).


Just for completeness... the AST library (
www.starlink.ac.uk/ast/) also
handles CD (both CDi_j and CDiiijjj) and PC matrices (both PCi_j and
PCiiijjj), and includes a parsing system (i.e. you give it an entire
header, and it sucks out the bits it needs and gives you a pointer to
an object representing all the WCS information in the header).

David

  #9  
Old October 29th 03, 07:08 PM
Doug Mink
external usenet poster
 
Posts: n/a
Default [fitsbits] [fitswcs] WCSLIB 3.3

David Berry wrote:

Just for completeness... the AST library (www.starlink.ac.uk/ast/) also
handles CD (both CDi_j and CDiiijjj) and PC matrices (both PCi_j and
PCiiijjj), and includes a parsing system (i.e. you give it an entire
header, and it sucks out the bits it needs and gives you a pointer to
an object representing all the WCS information in the header).


Since I didn't note it before, WCSTools also provides a single-call
parsing subroutine which ingests a FITS header and returns a WCS
structure or cascading WCS structures if the designated WCS depends
on others. FITS reading software is also included--my FITS experience
predates CFITSIO--so there is another single subroutien call which
returns the WCS structure(s) given a FITS or IRAF .imh file name.

-Doug Mink

 




Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

vB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
[fitsbits] [fitswcs] WCSLIB 3.3 Stephen Walton FITS 0 October 22nd 03 07:38 PM
[fitsbits] WCSLIB 3.3 Mark Calabretta FITS 0 October 22nd 03 10:24 AM
[fitsbits] AST V3.0 now available David Berry FITS 0 October 9th 03 04:40 PM
[fitsbits] proposed FITS MIME types Internet Draft Steve Allen FITS 0 October 1st 03 05:49 AM
[fitsbits] INSTRUME, TELESCOP, etc. Steve Allen FITS 2 August 4th 03 07:04 PM


All times are GMT +1. The time now is 03:08 PM.


Powered by vBulletin® Version 3.6.4
Copyright ©2000 - 2024, Jelsoft Enterprises Ltd.
Copyright ©2004-2024 SpaceBanter.com.
The comments are property of their posters.