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astCmpFrame - Create a CmpFrame   

Description:
This function creates a new CmpFrame and optionally initialises its attributes. A CmpFrame is a compound Frame which allows two component Frames (of any class) to be merged together to form a more complex Frame. The axes of the two component Frames then appear together in the resulting CmpFrame (those of the first Frame, followed by those of the second Frame).

Since a CmpFrame is itself a Frame, it can be used as a component in forming further CmpFrames. Frames of arbitrary complexity may be built from simple individual Frames in this way.

Synopsis:
AstCmpFrame *astCmpFrame( AstFrame *frame1, AstFrame *frame2, const char *options, ... )

Parameters:
frame1
Pointer to the first component Frame.
frame2
Pointer to the second component Frame.
options
Pointer to a null-terminated string containing an optional comma-separated list of attribute assignments to be used for initialising the new CmpFrame. The syntax used is identical to that for the astSet function and may include "printf" format specifiers identified by "%" symbols in the normal way.
...
If the "options" string contains "%" format specifiers, then an optional list of additional arguments may follow it in order to supply values to be substituted for these specifiers. The rules for supplying these are identical to those for the astSet function (and for the C "printf" function).

Returned Value:
astCmpFrame()
A pointer to the new CmpFrame.

Notes:
  • A null Object pointer (AST__NULL) will be returned if this function is invoked with the AST error status set, or if it should fail for any reason.



next up previous
Next: astCmpMap - Create a CmpMap
Up: AST Function Descriptions
Previous: astClone - Clone (duplicate) an Object pointer

AST A Library for Handling World Coordinate Systems in Astronomy
Starlink User Note 211
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