c_dspnt3d - interpolate double precision 3D data at specified points

       To use c_dspnt3d, load the NCAR Graphics library ngmath.

       Copyright (C) 2000
       University Corporation for Atmospheric Research

       The use of this Software is governed by a License Agreement.

UNIX                                           September 1997-1998                             c_dspnt3d(3NCARG)

       n           The number of input data points.

       xi          An array containing the X coordinates of the input data points.

       yi          An array containing the Y coordinates of the input data points.

       zi          An array containing the Z coordinates of the input data points.

       ui          An  array  containing  the  functional values of the input data points. That is, ui[l] is the
                   value of the input function at coordinate (xi[l],yi[l],zi[l]), for 0 <= l < n .

       m           The number of output data points (this may be "1").

       xo          An array of dimension m containing the X coordinates of the output data. The values in xo may
                   be in any order.

       yo          An array of dimension m containing the Y coordinates of the output data. The values in xo may
                   be in any order.

       zo          An array of dimension m containing the Z coordinates of the output data. The values in xo may
                   be in any order.

       uo          A pointer to a double. Space for m doubles is allocated for  uo  by  dspnt3d.  zo[i]  is  the
                   interpolated value at point (xo[i],yo[i],zo[i]) for 0 <= i < n .

       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 man page for dsgrid_errors.

       void c_dspnt3d(int, double [], double [], double [], double[]
       int, double [], double [], double [], double *, int *);

       c_dspnt3d - interpolate double precision 3D data at specified points

       dsgrid, dsgrid_params.

       Complete documentation for Dsgrid is available at URL
       http://ngwww.ucar.edu/ngdoc/ng/ngmath/dsgrid/dshome.html

       void c_dspnt3d(int n, double xi[], double yi[], double zi[], double ui[],
                      int m, double xo[], double yo[], double zo[], double *uo,
                      int *ier)

       This function is called to interpolate double precision 3D data at a specified point or points.