NAME

       c_natgrids - primary double precision C entry for natural neighbor gridding

FUNCTION PROTOTYPE

       double  *c_natgridd(int, double [], double [], double [],
                           int, int, double [], double [], int *);

SYNOPSIS

       double *c_natgridd (npnts, x, y, z, numxout, numyout, xi, yi, ier);

DESCRIPTION

       npnts       The number of input data points. (npnts > 3).

       x           An array containing the x coordinates of the input data points.

       y           An array containing the y coordinates of the input data points.

       z           An  array  containing  the  functional  values of the input data points. That is, z[m] is the
                   value of the input function at coordinate (x[m],y[m]), for 0 <= m < npnts.

       numxout     The number of x values in the output grid.

       numyout     The number of y values in the output grid.

       xi          An array of dimension numxout containing the x coordinates  of  the  output  data  grid.  The
                   values in xi must be increasing, but need not be equally spaced.

       yi          An  array  of  dimension  numyout  containing  the y coordinates of the output data grid. The
                   values in yi must be increasing, but need not be equally spaced.

       ier         An error value. If *ier is 0, then no errors were detected. If *ier is non-zero,  then  refer
                   to the man page for natgrid_errors for details.

USAGE

       c_natgridd  returns  a  pointer to a linear array of data that is is the interpolated grid stored in row-
       major order. That is, if out is declared as

       double *out;

       and we set:

         out = c_natgridd(numin, x, y, z, numxout, numyout, xo, yo, &ier);

       then out[i*numyout+j] is the interpolated function value at coordinate point (xo[i],yo[j]) for 0 <=  i  <
       numxout  and  0  <=  j  <  numyout.  The  space  for  out  is  allocated  internal  to  c_natgrids and is
       numxout*numyout double values in size.

ACCESS

       To use c_natgridd, load the NCAR Graphics library ngmath.

SEE ALSO

       natgrid, natgrid_params, c_nnseti, c_nngeti, c_nnsetrd, c_nngetrd, c_nnsetc, c_nngetc.

       Complete documentation for Natgrid is available at URL
       http://ngwww.ucar.edu/ngdoc/ng/ngmath/natgrid/nnhome.html

COPYRIGHT

       Copyright (C) 2000
       University Corporation for Atmospheric Research

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

UNIX                                             March 1997-1998                              c_natgridd(3NCARG)