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Extracting a Frame from a FrameSet

Although a FrameSet may be used in place of its current Frame in most situations, it is sometimes convenient to have direct access to a specified Frame within it. This may be obtained using the AST_GETFRAME function, as follows:

      FRAME = AST_GETFRAME( FRAMESET, AST__BASE, STATUS )

This would return a pointer (not a copy) to the base Frame within the FrameSet. Note the use of AST__BASE ([*]) as shorthand for the value of the FrameSet's Base attribute, which gives the base Frame's index.



next up previous
Next: Removing a Frame from a FrameSet
Up: Coordinate System Networks (FrameSets)
Previous: Using a FrameSet as a Frame

AST A Library for Handling World Coordinate Systems in Astronomy
Starlink User Note 210
R.F. Warren-Smith & D.S. Berry
30th April 2003
E-mail:ussc@star.rl.ac.uk

Copyright (C) 2003 Central Laboratory of the Research Councils