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The following describes the most significant changes which occurred
in the AST library between versions V1.8-8 and V1.8-13:
- 1.
- The FitsChan class has been modified so that LONPOLE keywords
are only produced by AST_WRITE when necessary. For zenithal projections such as
TAN, the LONPOLE keyword can always take its default value and so is
not included in the FITS header produced by AST_WRITE
Previously, the unnecessary production of a LONPOLE keyword could prevent
FrameSets being written out using encodings which do not support the
LONPOLE keyword (such as FITS-IRAF).
- 2.
- The FitsChan class has been modified to retain leading and trailing
spaces within COMMENT cards.
- 3.
- The FitsChan class has been modified to only use CTYPE comments as
axis labels if all non-celestial axes have unique non-blank comments
(otherwise the CTYPE keyword values are used as labels).
- 4.
- The FitsChan class has been modified so that it does not append a
trailing ``Z'' character to the end of DATE-OBS keyword values.
- 5.
- The FitsChan class has been modified to use latest list of FITS-WCS
projections, as described in the FITS-WCS paper II, "Representations of
celestial coordinates in FITS" (Calabretta & Greisen, draft dated 23
April 2002). Support has been retained for the polynomial correction
terms which previous drafts have allowed to be associated with TAN
projections.
- 6.
- The WcsMap class has additional projection types of AST__TPN
(which implements a distorted TAN projection) and AST__SZP. The AST__TAN
projection type now represents a simple TAN projection and has no
associated projection parameters. In addition, the usage of projection
parameters has been brought into line with the the FITS-WCS paper II.
- 7.
- The WcsMap class has been modified so that a "get" operation on a
projection parameter attribute will return the default value defined in the
FITS-WCS paper II if no value has been set for the attribute. Previously, a
value of AST__BAD was returned in such a situation.
- 8.
- The Frame class has new attributes Top(axis) and Bottom(axis) which
allow a ``plottable range'' to be specified for each Frame axis. The grid
produced by the AST_GRID routine will not extend beyond these limits.
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Up: Changes and New Features
Previous: Changes Introduced in V1.8-8
AST A Library for Handling World Coordinate Systems in Astronomy
Starlink User Note 210
R.F. Warren-Smith & D.S. Berry
30th April 2003
E-mail:ussc@star.rl.ac.uk
Copyright (C) 2003 Central Laboratory of the Research Councils