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AST_TRAN2
-
Transform 2-dimensional coordinates
- Description:
- This routine applies a Mapping to transform the coordinates of
a set of points in two dimensions.
- Invocation:
- CALL AST_TRAN2( THIS, NPOINT, XIN, YIN, FORWARD, XOUT, YOUT, STATUS )
- Arguments:
-
THIS = INTEGER (Given)
-
Pointer to the Mapping to be applied.
-
NPOINT = INTEGER (Given)
-
The number of points to be transformed.
-
XIN( NPOINT ) = DOUBLE PRECISION (Given)
-
An array of X-coordinate values for the input
(untransformed) points.
-
YIN( NPOINT ) = DOUBLE PRECISION (Given)
-
An array of Y-coordinate values for the input
(untransformed) points.
-
FORWARD = LOGICAL (Given)
-
A .TRUE. value indicates that the Mapping's forward
coordinate transformation is to be applied, while a .FALSE.
value indicates that the inverse transformation should be
used.
-
XOUT( NPOINT ) = DOUBLE PRECISION (Returned)
-
An array into which the
X-coordinates of the output (transformed) points will be written.
-
YOUT( NPOINT ) = DOUBLE PRECISION (Returned)
-
An array into which the
Y-coordinates of the output (transformed) points will be written.
-
STATUS = INTEGER (Given and Returned)
-
The global status.
- Notes:
- The Mapping supplied must have the value 2 for both its Nin
and Nout attributes.
Next: AST_TRANGRID - Transform a grid of positions
Up: AST Routine Descriptions
Previous: AST_TRAN1 - Transform 1-dimensional coordinates
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