NAME

       nnalg - a tool for displaying features of the Natgrid algorithm

SYNOPSIS

       nnalg algorithmic_data_file

DESCRIPTION

       "nnalg" takes a single argument which is a the name of a special file created by the
       Fortran subroutine NATGRIDS or the C function c_natgrids in the Natgrid package. This file
       contains data appropriate for displaying various features of the Natgrid algorithm. By
       default, this file is not created. In order to create it, you need to set the parameter
       adf in the Natgrid package.  You can additionally override the default file name of
       "nnalg.dat" by using the parameter alg.

       To invoke "nnalg", simply type the command:

       nnalg data_file

       By editing the data file, you have many options as to what is displayed and what the
       appearance of the plot looks like.

       The features that can be displayed are:

         1. The input data points
         2. The natural neighbor circumcircles
         3. The Delaunay triangulation, derived from the natural
            neighbor circumcircles
         4. The Voronoi polygons
         5. The first order natural neighbors of a given
            input point (or points)
         6. The second order natural neighbors of a given input
            point (or points)

       The first four items in the above list are displayed in the default case.

USAGE

       What gets displayed by nnalg depends on values in the input data file which can be changed
       by manual editing.

SEE ALSO

       natgrid

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

COPYRIGHT

       Copyright (C) 2000
       University Corporation for Atmospheric Research

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