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AST_NORMMAP - Create a NormMap

Description:
This function creates a new NormMap and optionally initialises its attributes.

A NormMap is a Mapping which normalises coordinate values using the AST_NORM routine of the supplied Frame. The number of inputs and outputs of a NormMap are both equal to the number of axes in the supplied Frame.

The forward and inverse transformation of a NormMap are both defined but are identical (that is, they do not form a real inverse pair in that the inverse transformation does not undo the normalisation, instead it reapplies it). However, the AST_SIMPLIFY function will replace neighbouring pairs of forward and inverse NormMaps by a single UnitMap.

Invocation:
RESULT = AST_NORMMAP( FRAME, OPTIONS, STATUS )
Arguments:
FRAME = INTEGER (Given)
A pointer to the Frame which is to be used to normalise the supplied axis values.
OPTIONS = CHARACTER $*$ ( $*$ ) (Given)
A character string containing an optional comma-separated list of attribute assignments to be used for initialising the new NormMap. The syntax used is identical to that for the AST_SET routine.
STATUS = INTEGER (Given and Returned)
The global status.
Returned Value:
AST_NORMMAP = INTEGER
A pointer to the new NormMap.
Notes:
  • A null Object pointer (AST__NULL) will be returned if this function is invoked with STATUS set to an error value, or if it should fail for any reason.
Status Handling
The protected interface to this function includes an extra parameter at the end of the parameter list descirbed above. This parameter is a pointer to the integer inherited status variable: "int $*$status".


next up previous 264
Next: AST_NULLREGION - Create a NullRegion
Up: AST Routine Descriptions
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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
24th May 2011
E-mail:ussc@star.rl.ac.uk

Copyright (C) 2009 Science \& Technology Facilities Council