NAME

       DSPNT2D - Interpolate at a single point (or points) in 2D in double precision

SYNOPSIS

       CALL DSPNT2D (N, X, Y, Z, M, XO, YO, ZO, IER)

DESCRIPTION

       N           (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,N.

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

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

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

       ZO          (Double   precision,  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.

USAGE

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

ACCESS

       To use DSPNT2D, load the NCAR Graphics library ngmath.

SEE ALSO

       dsgrid, dsgrid_params.

       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.