NAME

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

SYNOPSIS

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

DESCRIPTION

       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.

USAGE

       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.

ACCESS

       To use DSGRID2D, load the NCAR Graphics library ngmath.

SEE ALSO

       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

COPYRIGHT

       Copyright (C) 2000
       University Corporation for Atmospheric Research

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