DSPNT2S - Interpolate at a single point (or points) in 2D in single precision

       To use DSPNT2S, 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                               DSPNT2S(3NCARG)

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

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

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

       Z           (Real,  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,N.

       M           (Integer, Input) - The number of output data points (this may be "1").

       XO          (Real, Input) - An array of dimension M containing the X coordinates of the output data.  The
                   values in XO may be in any order.

       YO          (Real,  Input) - An array of dimension M containing the Y coordinates of the output data. The
                   values in YO may be in any order.

       ZO          (Real, Output) - An array of dimension M containing the interpolated  values.  ZO(I)  is  the
                   interpolated value at point (XO(I),YO(I)) for I=1,M.

       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.

       DSPNT2S - Interpolate at a single point (or points) in 2D in single precision

       dsgrid, dsgrid_params.

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

       CALL DSPNT2S (N, X, Y, Z, M, XO, YO, ZO, IER)

       This subroutine is called when you want to interpolate at an individual point or points.