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A Library for Handling
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Description:
This routine 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 determined by the
MeshSize attribute.
Invocation
CALL AST_GETREGIONMESH(
THIS, SURFACE, MAXPOINT, MAXCOORD, NPOINT, POINTS, STATUS )
Arguments
THIS =
INTEGER (Given)
Pointer to the Region.
SURFACE = LOGICAL (Given)
If .TRUE., the
returned points will cover the surface or the Region. Otherwise, they will fill the interior
of the Region.
MAXPOINT = INTEGER (Given)
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 first dimension of
the POINTS array. An error is reported if the number of points in the mesh exceeds this
number.
MAXCOORD = INTEGER (Given)
The length of the second dimension of the
POINTS array. An error is reported if the number of axes in the supplied Region exceeds this
number.
NPOINT = INTEGER (Returned)
The number of points in the returned mesh.
POINTS( MAXPOINT, MAXCOORD ) = DOUBLE PRECISION (Returned)
An array in
which to return the coordinates 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(POINT,COORD).
STATUS = INTEGER (Given and Returned)
The global status.
Notes:

An error is reported if the Region is unbounded.

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 nonlinear, 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).

If the Region defines an area within a SkyFrame that traverses zero longitude, the returned positions
will be normalised to avoid jumps of 2.PI radians in longitude (i.e. it will include longitude values less
than zero or greater than 2.PI).
Copyright (C) 2021 East Asian Observatory
 ←Prev
 AST
A Library for Handling
World Coordinate
Systems
in Astronomy  Next→
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