DSGRID2D - double precision Fortran entry for iterpolation from 2D random data to an output grid.

       To use DSGRID2D, 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                              DSGRID2D(3NCARG)

       NPNTS       (Integer, Input) - The number of input data points.

       X           (Double precision, Input) - An array containing the X coordinates of the input data points.

       Y           (Double precision, Input) - An array containing the Y coordinates of the input data points.

       Z           (Double  precision,  Input)  -  An  array  containing the functional values of the input data
                   points. That is, Z(L) is the value of the  input  function  at  coordinate  (X(L),Y(L)),  for
                   L=1,NPNTS.

       NUMXOUT     (Integer, Input) - The number of X values in the output grid.

       NUMYOUT     (Integer, Input) - The number of Y values in the output grid.

       XO          (Double precision, Input) - An array of dimension NUMXOUT containing the X coordinates of the
                   output data grid. The values in XO must be increasing, but need not be equally spaced.

       YO          (Double precision, Input) - An array of dimension NUMYOUT containing the Y coordinates of the
                   output data grid. The values in YO must be increasing, but need not be equally spaced.

       ZO          (Double  precision,  Output)  -   A  two-dimensional  array  of  dimension  NUMXOUT x NUMYOUT
                   containing the interpolated functional values. ZO(I,J) is  the  interpolated  value  at  grid
                   point (XO(I),YO(J)).

       IER         (Integer,  Output)  -  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 for details.

       DSGRID2D - double precision Fortran entry for iterpolation from 2D random data to an output grid.

       dsgrid, dsgrid_params, dsseti, dsgeti, dssetrd, dsgetrd, dssetc, dsgetc.

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

       CALL DSGRID2D (NPNTS, X, Y, Z, NUMXOUT, NUMYOUT, XO, YO, ZO, IER)

       DSGRID2D is the double precision gridding function for 2D data in the Dsgrid package.   The  behavior  of
       DSGRID2D  is  controlled by values set for the various parameters described in dsgrid_params.  Values for
       these parameters can be set using the subroutines DSSETI, DSSETRD, and DSSETC.

       In almost all cases the ngmath function NATGRIDD is superior to DSGRID2D for 2D interpolation.   See  the
       man page for NATGRIDD for details.