Starlink-pyast

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- The PolyMap class can now use an iterative Newton-Raphson method to
evaluate the inverse the inverse transformation if no inverse
transformation is defined when the PolyMap is created.

- The FitsChan class has a new method astWriteFits (AST_WRITEFITS)
which writes out all cards currently in the FitsChan to the associated
external data sink (specified either by the SinkFile attribute or the
sink function supplied when the FitsChan was created), and then empties
the FitsChan.

- The FitsChan class has a new method astReadFits (AST_READFITS)
which forces the FitsChan to reads cards from the associated external
source and appends them to the end of the FitsChan.

- The FitsChan class has a new read-only attribute called "Nkey", which
holds the number of keywords for which values are held in a FitsChan.

- The FitsChan class has a new read-only attribute called "CardType", which
holds the data type of the keyword value for the current card.

- The FitsChan astGetFits<X> (AST_GETFITS<X>) methods can now be used to
returned the value of the current card.

- If the FitsChan astRead method reads a FITS header that uses the
-SIP (Spitzer) distortion code within the CTYPE values, but which does
not provide an inverse polynomial correction, and for which the PolyTran
method of the PolyMap class fails to create an accurate estimate of the
inverse polynomial correction, then an iterative method will be used to
evaluate the inverse correction for each point transformed.

- The Object class has a new function astToString (C only), which creates
an in-memory textual serialisation of a given AST Object. A corresponding
new function called astFromString re-creates the Object from its
serialisation.

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- All classes of Channel can now read to and write from specified text
files, without the need to provide source and sink functions when the
Channel is created. The files to use are specified by the new attributes
SourceFile and SinkFile.

- The FitsChan class now ignores trailing spaces in character-valued WCS
keywords when reading a FrameSet from a FITS header.

- If the FitsChan astRead method reads a FITS header that uses the -SIP
(Spitzer) distortion code within the CTYPE values, but which does not
provide an inverse polynomial correction, the FitsChan class will now use
the PolyTran method of the PolyMap class to create an estimate of the
inverse polynomial correction.

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- The FitsChan class support for the IRAF-specific "TNX" projection has
been extended to include reading TNX headers that use a Chebyshev
representation for the distortion polynomial.

- The FitsChan class support for the IRAF-specific "ZPX" projection has
been extended to include reading ZPX headers that use simple or Chebyshev
representation for the distortion polynomial.

- A bug has been fixed in the FitsChan class that caused headers
including the Spitzer "-SIP" distortion code to be read incorrectly if no
inverse polynomial was specified in the header.

- A new attribute called PolyTan has been added to the FitsChan class. It
can be used to indicate that FITS headers that specify a TAN projection
should be interpreted according to the "distorted TAN" convention
included in an early draft of FITS-WCS paper II. Such headers are created
by (for instance) the SCAMP tool (http://www.astromatic.net/software/scamp).

- The PolyMap class now provides a method called astPolyTran (AST_POLYTRAN)
that adds an inverse transformation to a PolyMap by sampling the forward
transformation on a regular grid, and then fitting a polynomial function
from the resulting output values to the grid of input values.

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- Tables can now have any number of parameters describing the global
properties of the Table.

- Frames now interpret the unit string "A" as meaning "Ampere" rather
than "Angstrom", as specified by FITS-WCS paper I.

- A bug has been fixed in the astFindFrame (AST_FINDFRAME) method that
allowed a template Frame of a more specialised class to match a target
frame of a less specialised class. For example, this bug would allow a
template SkyFrame to match a target Frame. This no longer happens.

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- New functions astBBuf (AST_BBUF) and astEBuf (AST_EBUF) have been added
to the Plot class. These control the buffering of graphical output
produced by other Plot methods.

- New functions astGBBuf and astGEBuf have been added to the interface
defined by file grf.h. The ast_link command has been modified so that the
-grf_v3.2 switch loads dummy versions of the new grf functions. This
means that applications that use the -grf_v3.2 switch should continue to
build without any change. However, the new public functions astBBuf and
astEBuf described in the previous item will report an error unless the
new grf functions are implemented. If you choose to implement them, you
should modify your linking procedure to use the -grf (or -grf_v5.6)
switch in place of the older -grf_v3.2 switch. See the description of the
ast_link command for details of these switches.

- New method astGetRegionMesh (AST_GETREGIONMESH) returns a set of
positions covering the boundary, or volume, of a supplied Region.

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- The FitsChan "TabOK" attribute is now an integer value rather
than a boolean value. As in previous versions, it is used to indicate
whether the "-TAB" algorithm should be supported by the astRead
(AST_READ) and astWrite (AST_WRITE) methods, but in addition it is now
also used to give the version number to assign to any table gebnerated as
a consequence of calling astWrite (AST_WRITE). A negative or zero value
(the default) indicates that support for the -TAB algorithm is not
available, where as a positive non-zero value indicates that support is
available and also gives the table version number to use when creating
subsequent -TAB headers.