AST Version 8.7.1

Main changes since v8.6.3:

• A new subclass of Region called "Moc" has been added. A Moc describes an arbitrary region of the sky in the form of a set of HEALPix cells using the IVOA Multi-Order Coverage scheme. Version 1.1 of the the MOC recommendation is supported, including string and JSON encoded of MOCs.

• A new subclass of Channel called "MocChan" has been added. This works with the Moc class to provide further options for reading and writing MOCs as strings.

• The FitsChan class will now read FITS-WCS headers that have alternate axis descriptions but no primary axis descriptions.

• The Region class has a new method called astGetRegionDisc, which returns the centre and radius of a disc that just encloses a 2-dimensional Region.

• The Bounded attribute defined by the Region class is now always non-zero for Regions defined within a SkyFrame, regardless of whether the Region has been negated. Previously, it was non-zero only if the Region had not been negated. Note, this change only affects Regions defined within SkyFrames.

AST Version 8.6.3

Main changes in this release:

• Small memory leaks in Region and FitsChan classes have been fixed.

• A bug that could cause an internal buffer overrun within the FitsChan
  class when writing out a FITS-WCS spectral axis with the "-LOG" algorithm
  has been fixed.

• The test that a Mapping conforms to the requirements of the SIP FITS
  distortion scheme has been improved.

• The astRebinSeq method of the Mapping class can now use a different
  weight when pasting each separate input data array into the output mosaic.

AST Version 8.6.2

Main Changes in this Version:

• The astWrite method of the FitsChan class can now create FITS-WCS headers
  that include keyords describing focal plane distortion using the
  conventions of the Spitzer SIP scheme. This is however only possible if
  the SipOK attribute of the FitsChan is set to a non-zero value (which is
  the default), and the FrameSet being written out contains an appropriate
  PolyMap that conforms to the requirements of the SIP convention.

• The behaviour of the astLinearApprox method of the Mapping class has
  been changed in cases where the Mapping being approximated generates bad
  (AST__BAD) values for one or more of its outputs. Previously, any such
  Mapping would be deemed non-linear and no fit would be returned. Now, a
  fit is returned, provided the other outputs of the Mapping are linear,
  but the fit contains AST__BAD values for the coefficients describing the
  bad Mapping output.

AST Version 8.6.1

Main Changes in V8.6.1:

• A new function call astCreatedAt is now available that returns the function name, file path and line number at which an AST object was first created.

• The number of digits used to format floating point values has been increased in order to avoid loss of precision when converting from binary to string and back to binary. This could cause very small changes in numerical values returned by AST functions.

• If a FrameSet is supplied as the "Map" argument to astAddFrame, it now extracts and stores the base->current Mapping from the supplied FrameSet. Previously, the entire FrameSet was stored as the Mapping.

Main Changes in V8.5.1:

• A new class of Mapping called ChebyMap has been added. This is a Mapping that implements Chebyshev polynomial transformations.

• If the function that delivers error messages to the user (astPutErr) is re-implemented, the new version can now be registered at run-time using the new astSetPutErr function. Previously, the new version needed to be linked into the application at build time.

• A bug has been fixed in the PolyMap class that caused incorrect values to be returned for the TranForward and TranInverse attributes if the PolyMap has been inverted.

• The KeyMap class has a new method called astMapGetC (AST_MAPGETC) which returns a named entry as a single string. If the entry is a vector the returned string is a comma-separated list of its elements, enclosed in parentheses.

• The Frame class now has a new attribute caled DTAI, which can be used to specify the number of leap seconds at the moment represented by the Frame's Epoch attribute. By default, the internal look-up table of leap seconds contained within AST is used. The DTAI attribute allows old versions of AST, which may not include the most recent leap seconds, to be used with new data.

• The TimeMap class has been changed so that some conversions now require a "Dtai" value (i.e. the number of leap seconds) to be supplied by the caller. If AST__BAD is supplied for "Dtai", the internal look-up table of leap seconds contained withn AST will be used. The conversions affected are those between TAI and UTC, and those between TT and TDB.

AST Version 8.4.0

• The PAL library files included in the AST distribution have been updated
  to PAL version 0.9.7.
• Multiple identical NormMaps in series will now be simplified to a
  single NormMap.
• A NormMap that encapsulates a basic Frame will now be simplified to a
  UnitMap.
• The astTimeAdd (AST_TIMEADD) method of the TimeMap class now include an
  extra argument that gives the number of values supplied in the arguments
  array. Note, any existing code that uses this method will need to be
  changed.
• The astSlaAdd (AST_SLAADD) method of the SlaMap class now include an
  extra argument that gives the number of values supplied in the arguments
  array. Note, any existing code that uses this method will need to be
  changed.
• The astSpecAdd (AST_SPECADD) method of the SpecMap class now include an
  extra argument that gives the number of values supplied in the arguments
  array. Note, any existing code that uses this method will need to be
  changed.
• If the astMapRegion (AST_MAPREGION) method is used to map a Region into
  a new Frame that has fewer axes than the original Region, and if the
  inverse transformation of the supplied Mapping does not specify a value
  for the missing axes, then those axes are removed entirely from the
  Region. Previously they were retained, but supplied with bad values. This
  affects the number of mesh points per axes for such Regions, and so
  affects the accuracy of overlap determination.