[fitsbits] WCSLIB 4.1

Greetings,

WCSLIB 4.1 is now available from http://www.atnf.csiro.au/~mcalabre.

This release contains much added functionality, particularly for parsing
FITS headers and constructing coordinate systems from them, including a
full implementation of -TAB coordinates (Paper III); units conversion
(Paper I); and translation of non-standard constructs. The README file
now provides an introduction and overview of the library for new
programmers, and as previously, all functions are fully documented in
the header files.

In summary, FITS WCS Papers I, II, and III are now fully implemented in
WCSLIB 4.1 except for:

1) Parsing of WCS cards for image arrays in binary tables and for
pixel lists (Paper I, Sect. 3).

2) VELANGLa (Paper III, Appendix A).

Change notes for the C library are appended. The first part of this
provides a summary of the main changes.

Mark Calabretta
ATNF



WCSLIB version 4.1 (2005/08/31)
-------------------------------

Summary of added functionality:

+ -TAB coordinate axes are now fully implemented in the WCSLIB driver
functions (in wcs.{h,c}); multiple -TAB axes are supported. A new
function, wcstab(), which is automatically invoked by wcspih(), parses
-TAB-related header cards and sets up structs for a separate routine
that reads the necessary arrays from a FITS binary table extension.

An implementation of this routine in CFITSIO, fits_read_wcstab(), is
provided. Note however that the interface of this function is
experimental, and the code itself must be considered beta-release in
WCSLIB 4.1.

+ Units specifications, either from CNAMEia or inline comments (with
brackets), of arbitrary complexity are now fully implemented via a parser,
wcsulex(), and converter, wcsunits(). This is invoked automatically by
wcsset().

+ Translators for non-standard WCS constructs are provided. These cover
date formats, units specifications, defunct celestial projection types,
AIPS spectral axis types, and the repair of malformed cylindrical
coordinate systems.

+ wcspih() now has options to remove the WCS cards it has processed from the
header and a new generic FITS header parser, fitshdr(), may be used to
parse the remaining non-WCS cards. In addition to the more basic types,
it handles 64-bit and 'very long' (70 digit) integer keyvalues, and also
continued string keyvalues. It also does keyword matching and extracts
units specifications in inline comments.

+ -LOG coordinates are now implemented independently of spectral coordinate
types. Multiple -LOG axes are supported.

+ New function wcssptr() translates the spectral axis in a wcsprm struct to
the required type.

+ The README file now gives an introduction to, and complete overview of,
WCSLIB. It provides a point of entry to programming with WCSLIB.
Complete descriptions and usage notes for all functions are contained in
the header files.

+ The FORTRAN wrappers and test programs are now completely up-to-date with
respect to the C implementation.

+ All code, including the FORTRAN wrappers, PGSBOX, and all test programs,
now pass 'purify' without memory leaks, uninitialized memory reads, memory
access violations, or other memory faults.

Change notes:

* Added options to wcspih() to remove WCS cards from the input header leaving
only non-WCS cards behind. Modified test programs tpih1.c and tpih2.c to
use CFITSIO optionally via preprocessor macro DO_CFITSIO.

* New function wcstab() in wcshdr.{h,c} parses -TAB-related header cards and
sets up structs for a separate routine that reads the necessary arrays from
a FITS binary table extension. New test/demo program twcstab.c using header
defined in wcstab.cards.

* CFITSIO implementation, fits_read_wcstab() in getwcstab.{h,c}, of a
function, independent of WCSLIB, for extracting arrays from a binary table
as required in constructing -TAB coordinates.

* New units specification parser, wcsulex() in wcsunits.h and wcsulex.l, and
converter, wcsunits() in wcsunits.{h,c}. New test/demo program tunits.c.

* New parser for non-standard units specifications, wcsutrn() in wcsunits.h
and wcsutrn.l, also tested by tunits.c.

* New functions datfix(), unitfix() (which applies wcsutrn()), celfix(), and
spcfix() join cylfix() in wcsfix.{h,c} to translate various forms of non-
standard or quasi-standard FITS WCS keyvalues in a wcsprm struct. wcsfix()
applies all of these in sequence. New test/demo program twcsfix.c, with
wcsfix() also now invoked by tpih1.c.

* New generic FITS header parser, fitshdr() in fitshdr.{h,l}. New test/demo
program tfitshdr.c uses wcs.cards with extra non-WCS cards added.

* -LOG coordinates are now treated as a coordinate type separate from spectral
coordinates, implemented via log.{h,c} and test program tlog.c. The
logarithmic functions were removed from spx.{h,c}, and spc.c.

* Extensive changes to wcs.{h,c} to support multiple -TAB and -LOG coordinate
axes and units conversion. Substantially changed the test program, twcs.c,
to test the more general functionality.

* New function wcssptr() in wcs.{h,c} translates the spectral axis in a wcsprm
struct.

* Added DATE-AVG to wcsprm. Also ntab, tab, nwtb, and wtb required for -TAB
implementation. Define struct wtbarr.

* Added a types[] member to the wcsprm struct to identify axis coordinate
types using a four-digit code.

* Use memset() in wcsini() to null-fill character arrays in the wcsprm struct
so that they don't appear to be padded with garbage when displayed by gdb.

* Do alias translation for AIPS-convention spectral types in wcsset() using
spctyp(). If wcsset() finds a CTYPEia in "4-3" form with an unrecognized
algorithm code it now returns an error rather than assume that it's a linear
axis. wcsset() now also resets lonpole and latpole to the values actually
used.

* Modified spctyp() to translate AIPS-convention spectral ctypes, and modified
the argument list to return the parsed spectral type and algorithm code.
The return arguments will not be modified if CTYPEia is not a valid spectral
type; zero-pointers may be specified for any that are not of interest.
Removed the external const variables, spc_codes and spc_ncode, as their
function is now fulfilled by spctyp().

* Fixed a bug in spctrn() in resolving ctypeS2 wildcarding.

* Added latpreq member to the celprm struct, set by celset() to indicate how
LATPOLE is used. Augmented tcel2.c to report it.

* New function tabmem() in tab.{h,c} takes control of user-allocated memory.

* tabini() allows K == 0 and also K[m] == 0 to initialize partially the tabprm
struct (for wcstab()). It now does fine-grained bookkeeping of memory
allocation for the index arrays and allocates each individually.
tabprm.index[] == 0x0 is recognized as default indexing in tabset(),
tabx2s() and tabs2x().

* The *prt() functions report parameters to an extra decimal place.

* tabprt() prints the array index for elements of the coordinate and index
vectors.

* Set the 0th element in all *_errmsg arrays to "Success".

* Extracted string utility functions used by WCSLIB into wcsutil.{h,c}.

* Removed support for K&R C.