## Changes Introduced in V1.8-7

The following describes the most significant changes which occurred in the AST library between versions V1.8-5 and V1.8-7:

1. 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.

2. A bug has been fixed which could result in axis Format attributes set by the user being ignored under certain circumstances.

3. 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.

4. A bug has been fixed which could prevent attribute settings from being read correctly by astSetastSet, etc., on certain platforms (MacOS, for instance).