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astGetRegionMesh - Return a mesh of points covering the surface or volume of a Region

Description:
This function returns the axis values at a mesh of points either covering the surface (i.e. boundary) of the supplied Region, or filling the interior (i.e. volume) of the Region. The number of points in the mesh is approximately equal to the MeshSize attribute.
Synopsis:
void astGetRegionMesh( AstRegion $*$this, int surface, int maxpoint, int maxcoord, int $*$npoint, double $*$points )
Parameters:
this
Pointer to the Region.
surface
If non-zero, the returned points will cover the surface or the Region. Otherwise, they will fill the interior of the Region.
maxpoint
If zero, the number of points in the mesh is returned in "$*$npoint", but no axis values are returned and all other parameters are ignored. If not zero, the supplied value should be the length of the second dimension of the "points" array. An error is reported if the number of points in the mesh exceeds this number.
maxcoord
The length of the first dimension of the "points" array. An error is reported if the number of axes in the supplied Region exceeds this number.
npoint
A pointer to an integer in which to return the number of points in the returned mesh.
points
The address of the first element in a 2-dimensional array of shape "[maxcoord][maxpoint]", in which to return the coordinate values at the mesh positions. These are stored such that the value of coordinate number "coord" for point number "point" is found in element "points[coord][point]".
Notes:
  • If the coordinate system represented by the Region has been changed since it was first created, the returned axis values refer to the new (changed) coordinate system, rather than the original coordinate system. Note however that if the transformation from original to new coordinate system is non-linear, the shape within the new coordinate system may be distorted, and so may not match that implied by the name of the Region subclass (Circle, Box, etc).


next up previous 264
Next: astGetRegionPoints - Returns the positions that define the given Region
Up: AST Function Descriptions
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AST A Library for Handling World Coordinate Systems in Astronomy
Starlink User Note 211
R.F. Warren-Smith & D.S. Berry
24th May 2011
E-mail:ussc@star.rl.ac.uk

Copyright (C) 2009 Science \& Technology Facilities Council