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MathMap - Transform coordinates using mathematical expressions

Description:
A MathMap is a Mapping which allows you to specify a set of forward and/or inverse transformation functions using arithmetic operations and mathematical functions similar to those available in Fortran. The MathMap interprets these functions at run-time, whenever its forward or inverse transformation is required. Because the functions are not compiled in the normal sense (unlike an IntraMap), they may be used to describe coordinate transformations in a transportable manner. A MathMap therefore provides a flexible way of defining new types of Mapping whose descriptions may be stored as part of a dataset and interpreted by other programs.

Constructor Function:
AST_MATHMAP

Inheritance
The MathMap class inherits from the Mapping class.

Attributes
In addition to those attributes common to all Mappings, every MathMap also has the following attributes:

  • Seed: Random number seed
  • SimpFI: Forward-inverse MathMap pairs simplify?
  • SimpIF: Inverse-forward MathMap pairs simplify?

Functions
The MathMap class does not define any new routines beyond those which are applicable to all Mappings.



next up previous
Next: MatrixMap - Map coordinates by multiplying by a matrix
Up: AST Class Descriptions
Previous: Mapping - Inter-relate two coordinate systems

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