Provided by: libncarg-dev_6.6.2.dfsg.1-10build2_amd64 

NAME
c_csstrid - calculates a Delaunay triangulation for data on a sphere
FUNCTION PROTOTYPE
int *c_csstrid(int, double [], double [], int *, int *);
SYNOPSIS
int *c_csstrid(n, rlat, rlon, nt, ier);
DESCRIPTION
n The number of input data points, n > 2.
rlat An array containing the latitudes of the input data, expressed in degrees. The first three
points must not be collinear (lie on a common great circle).
rlon An array containing the longitudes of the input data, expressed in degrees.
nt *nt is the number of triangles in the triangulation, unless *ier is non-zero, in which case
*nt = 0. Where nb is the number of boundary points on the convex hull of the data, if nb is
greater than 3, then *nt = 2n-nb-2, otherwise *nt = 2n-4. The input data are considered to
be bounded if they all lie in one hemisphere.
ier An error return value. If *ier is returned as 0, then no errors were detected. If *ier is
non-zero, then refer to the error list in cssgrid_errors for details.
USAGE
c_csstrid is called to find a Delaunay triangulation of data randomly positioned on the surface of a
sphere. c_csstrid is a double precision version of c_csstri.
RETURN VALUE
c_csstrid returns a pointer to a linear array that contains a sequence of integer triples. The elements
of a triple are indices of vertices of a triangle. Each index references an original data point as it
occurs in sequence in the input data set (numbering starts at 0). For example, if the triple <5,0,2> were
in the list of triples, then (rlat[5],rlon[5]), (rlat[0],rlon[0]), and (rlat[2],rlon[2]) would be
vertices of a triangle in the Delaunay triangulation.
ACCESS
To use c_csstrid, load the NCAR Graphics library ngmath.
SEE ALSO
css_overview, c_cssgrid, c_csstri, cssgrid_errors
Complete documentation for Cssgrid is available at URL
http://ngwww.ucar.edu/ngdoc/ng/ngmath/cssgrid/csshome.html
COPYRIGHT
Copyright (C) 2000
University Corporation for Atmospheric Research
The use of this Software is governed by a License Agreement.
UNIX May 2000 c_csstrid(3NCARG)