The following describes the most significant changes which
occurred in the AST library between versions V1.8-5 and V1.8-7:
- A new attribute called CarLinCarLin has been added to the FitsChanFitsChan class
which controls the way CAR projections are handled when reading a
FrameSetFrameSet from a non-native FITS header. Some FITS writers use a CAR
projection to represent a simple linear transformation between pixel
coordinates and celestial sky coordinates. This is not consistent with
the definition of the CAR projection in the draft FITS-WCS standard, which
requires the resultant MappingMapping to include a 3D rotation from native
spherical coordinates to celestial spherical coordinates, thus making the
Mapping non-linear. Setting CarLin to 1 forces
astReadastRead
to ignore the FITS-WCS standard and treat any CAR projections as simple
linear Mappings from pixel coordinates to celestial coordinates.
- A bug has been fixed which could result in axis Format attributes
set by the user being ignored under certain circumstances.
- A bug in the way tick marks positions are selected in the PlotPlot class
has been fixed. This bug could result in extra ticks marks being displayed at
inappropriate positions. This bug manifested itself, for instance, if the
Mapping represented by the Plot was a simple Cartesian to Polar Mapping.
In this example, the bug caused tick marks to be drawn at negative radius
values.
- A bug has been fixed which could prevent attribute settings from
being read correctly by
astSetastSet,
etc., on certain platforms (MacOS, for instance).