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Compound Frames (CmpFrames)

We now turn to a rather special form of Mapping, the CmpFrame. The Frames we have considered so far have been atomic, in the sense that they represent pre-defined elementary physical domains. A CmpFrame, however, is a compound Frame. In essence, it is a structure for containing other Frames and its purpose is to allow those Frames to work together in various combinations while appearing as a single Object. A CmpFrame's behaviour is therefore not pre-defined, but is determined by the other Frames it contains (its ``component'' Frames).

As with compound Mappings, compound Frames can be nested within each other, forming arbitrarily complex Frames.


Subsections

next up previous 264
Next: Creating a CmpFrame
Up: AST A Library for Handling World Coordinate Systems in Astronomy
Previous: Attributes which Qualify Time Coordinate Systems

AST A Library for Handling World Coordinate Systems in Astronomy
Starlink User Note 211
R.F. Warren-Smith & D.S. Berry
24th May 2011
E-mail:ussc@star.rl.ac.uk

Copyright (C) 2009 Science \& Technology Facilities Council