[fitsbits] WCSLIB 3.1, WCS Paper IV

[Mark Calabretta]

Greetings,

WCSLIB 3.1 is now available from
----------

   http://www.atnf.csiro.au/~mcalabre/WCS

This is a major release, with interfaces differing from those of
WCSLIB 2.x.  It implements most of Papers I & II (as published),
and the current draft of Paper III, and its more extensible design
should accomodate Paper IV.

The main differences between WCSLIB 3.1 and 2.9 are:

   1) Fully vectorized interfaces (C preprocessor macros are available
      to implement the scalar interfaces of the proj.c, sph.c, and lin.c
      routines from WCSLIB 2.x).

   2) Implementation of Paper II, Sect. 2.5: User-specified (phi0, theta0).

   3) Implementation of Paper III (excluding "-TAB").

   4) Memory management is now implemented in the wcs.c routines.

   5) New extensible design should accomodate Paper IV (and any other)
      without further change to the function interfaces.

   6) FORTRAN is now supported via wrappers on the C library.

Note that although placeholders have been provided in the wcsprm struct
for CUNITi cards, these are not implemented as yet.

As usual, the distribution includes the latest version of PGSBOX.  This
has been adapted to WCSLIB 3.x, now comes with a C wrapper, and also now
handles calendar date axes. 

Refer to the README and CHANGES files in the distribution for more
information.
 

WCS Paper IV
------------
A draft of Paper IV, "Representations of distortions in FITS world
coordinate systems", dated 2002/03/12, is also now available.  Hitherto
this has had limited circulation, but it is now being made available for
general consideration. The draft presents a framework but is obviously
incomplete - several sections exist only as headers.

Please read Paper IV and consider whether it can handle your favourite
irregular coordinate system.  However, please note that I will not be
available to discuss Paper IV or WCSLIB, or any other WCS issues (or
anything!) till July at the earliest.  

Mark Calabretta
ATNF