NNPNTINITD - Enter single point mode in double precision

       To use NNPNTINITD, 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                                             March 1997-1998                              NNPNTINITD(3NCARG)

       NPNTS       (Integer, Input) - The number of input data points. (NPNTS > 3).

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

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

       Z           (Double  precison,  Input)  - An array of dimension NPNTS 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.

       NNPNTINITD - Enter single point mode in double precision

       natgrid, natgrid_params, natgridd, nnpntd, nnpntendd.

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

       CALL NNPNTINITD (NPNTS, X, Y, Z)

       This  subroutine  is  called  when  you want to interpolate at individal points.  It is an initialization
       routine that sets up some internal variables and does this initial triangulation.   To  actually  do  the
       interplation, use subroutine NNPNTD.  To terminate single point mode, use the subroutine NNPNTENDD.