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.
AST A Library for Handling World Coordinate Systems in Astronomy