1nnalg(1NCARG) NCAR GRAPHICS nnalg(1NCARG)
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6 nnalg - a tool for displaying features of the Natgrid algorithm
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9 nnalg algorithmic_data_file
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12 "nnalg" takes a single argument which is a the name of a special file
13 created by the Fortran subroutine NATGRIDS or the C function c_natgrids
14 in the Natgrid package. This file contains data appropriate for
15 displaying various features of the Natgrid algorithm. By default, this
16 file is not created. In order to create it, you need to set the
17 parameter adf in the Natgrid package. You can additionally override
18 the default file name of "nnalg.dat" by using the parameter alg.
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20 To invoke "nnalg", simply type the command:
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22 nnalg data_file
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24 By editing the data file, you have many options as to what is displayed
25 and what the appearance of the plot looks like.
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27 The features that can be displayed are:
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29 1. The input data points
30 2. The natural neighbor circumcircles
31 3. The Delaunay triangulation, derived from the natural
32 neighbor circumcircles
33 4. The Voronoi polygons
34 5. The first order natural neighbors of a given
35 input point (or points)
36 6. The second order natural neighbors of a given input
37 point (or points)
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39 The first four items in the above list are displayed in the default
40 case.
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43 What gets displayed by nnalg depends on values in the input data file
44 which can be changed by manual editing.
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47 natgrid
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49 Complete documentation for nnalg is available at URL
50 http://ngwww.ucar.edu/ngdoc/ng/ngmath/natgrid/algorithm.html
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53 Copyright (C) 2000
54 University Corporation for Atmospheric Research
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56 This documentation is free software; you can redistribute it and/or
57 modify it under the terms of the GNU General Public License as
58 published by the Free Software Foundation; either version 2 of the
59 License, or (at your option) any later version.
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61 This software is distributed in the hope that it will be useful, but
62 WITHOUT ANY WARRANTY; without even the implied warranty of
63 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
64 General Public License for more details.
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66 You should have received a copy of the GNU General Public License along
67 with this software; if not, write to the Free Software Foundation,
68 Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
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73UNIX March 1997-1998 nnalg(1NCARG)