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Mapping
-
Inter-relate two coordinate systems
- Description:
- This class provides the basic facilities for transforming a set
of coordinates (representing "input" points) to give a new set
of coordinates (representing "output" points). It is used to
describe the relationship which exists between two different
coordinate systems and to implement operations which make use of
this (such as transforming coordinates and resampling grids of
data). However, the Mapping class does not have a constructor
function of its own, as it is simply a container class for a
family of specialised Mappings which implement particular types
of coordinate transformation.
- Constructor Function:
- None.
-
Inheritance
- The Mapping class inherits from the Object class.
-
Attributes
- In addition to those attributes common to all Objects, every
Mapping also has the following attributes:
- Invert: Mapping inversion flag
- IsLinear: Is the Mapping linear?
- IsSimple: Has the Mapping been simplified?
- Nin: Number of input coordinates for a Mapping
- Nout: Number of output coordinates for a Mapping
- Report: Report transformed coordinates?
- TranForward: Forward transformation defined?
- TranInverse: Inverse transformation defined?
-
Functions
- In addition to those routines applicable to all Objects, the
following routines may also be applied to all Mappings:
Next: MathMap - Transform coordinates using mathematical expressions
Up: AST Class Descriptions
Previous: LutMap - Transform 1-dimensional coordinates using a lookup table
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