## Changes Introduced in V1.8-2

The following describes the most significant changes which have occurred in the AST library between versions V1.7 and V1.8-2:

1. The SkyFrameSkyFrame class has a new attribute called NegLonNegLon which allows longitude values to be displayed in the range 314#314 to 315#315, instead of the usual range zero to 316#316.

2. Some new functions (astAngleastAngle, astAxAngleastAxAngle, astResolveastResolve, astOffset2astOffset2, astAxOffsetastAxOffset, astAxDistanceastAxDistance) have been added to the FrameFrame class to allow navigation of the coordinate space to be performed without needing to know the underlying geometry of the co-ordinate system (for instance, whether it is Cartesian or spherical).

   Note, version 1.8-1 contained many of these facilities, but some have been changed in version 1.8-2. Particularly, positions angles are now referred to the second Frame axis for all classes of Frames (including SkyFrames), and the astBear function has been replaced by astAxAngle.