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...Validate WCS Information

Once you have read WCS information from a dataset, as in [*], you may wish to check that you have been successful. The following will detect and classify the things that might possibly go wrong:

      IF ( STATUS .NE. 0 ) THEN
         <an error occurred (a message will have been issued)>
      ELSE IF ( WCSINFO .EQ. AST__NULL ) THEN
         <there was no WCS information present>
      ELSE IF ( AST_GETC( WCSINFO, 'Class', STATUS ) .NE. 'FrameSet' ) THEN
         <something unexpected was read (i.e. not a FrameSet)>
      ELSE
         <WCS information was read OK>
      END IF

For more information about detecting errors in AST routines, see [*]. For details of how to validate input data read by AST, see [*] and [*].



next up previous
Next: ...Display AST Data
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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