dist_plot

dist_plot, an Octave code which creates a color contour plot of the distance function, as used in Strang and Persson's distmesh() program.

Usage:

dist_plot ( p, t, @fd )

• p, a list of node coordinates;
• t, a list of node indices forming a triangulation of the nodes;
• @fd, points to a distance function d = fd ( p ) which computes the distance d from the region to any point p.

Licensing:

DIST_PLOT is based in part on DISTMESH, which is Copyright (C) 2004 Per-Olof Persson.

This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 2 of the License, or (at your option) any later version.

This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.

You should have received a copy of the GNU General Public License along with this program; if not, write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.

If you use DISTMESH in any program or publication, please acknowledge its authors by citing the reference.

Languages:

dist_plot is available in a MATLAB version and an Octave version.

Related Data and Programs:

dist_plot_test

distmesh, an Octave code which is Strang and Persson's code for generating meshes over regions with an associated distance function.

levels, an Octave code which makes a contour plot, choosing the contour levels using random sampling.

table_io, an Octave code which reads and writes files using the TABLE format.

test_triangulation, an Octave code which defines some test regions for triangulation.

triangulation_order3, a data directory which discusses order 3 triangulations; The node and triangle files input to DIST_PLOT are an example of such triangulations.

triangulation_plot, an Octave code which can make a plot of a triangulation.

Reference:

1. Per-Olof Persson, Gilbert Strang,
   A Simple Mesh Generator in MATLAB,
   SIAM Review,
   Volume 46, Number 2, June 2004, pages 329-345.

Source Code:

• dcircle.m returns the signed distance of one or more points to a circle.
• ddiff.m returns the signed distance of one or more points to a region defined as the set difference of two regions.
• dexpr.m computes the signed distance for a general implicit expression.
• dintersect.m returns the signed distance to a region that is the intersection of two regions.
• dist_plot.m displays a plot of the distance function over the region.
• dpoly.m returns the signed distance of one or more points to a polygon.
• drectangle.m returns the signed distance of one or more points to a rectangle.
• dsegment.m returns the signed distance of one or more points to a set of line segments.
• dsegment.dll (binary file), a Windows DLL file, returns the signed distance of one or more points to a set of line segments. This version is faster than the M-file.
• dunion.m returns the signed distance to a region that is the union of two regions.
• file_column_count.m counts the number of columns in a table file.
• file_row_count.m counts the number of rows in a table file.
• i4mat_data_read.m reads the data of an I4MAT file.
• i4mat_header_read.m reads the header of an I4MAT file.
• i4mat_read.m reads an I4MAT file.
• i4mat_write.m writes an I4MAT file.
• protate.m rotates a set of points by a given angle.
• pshift.m shifts a set of points by a given increment.
• r8mat_data_read.m reads the data of an R8MAT file.
• r8mat_header_read.m reads the header of an R8MAT file.
• r8mat_write.m writes an R8MAT file.
• s_len_trim.m returns the length of a string to the last nonblank.
• s_word_count.m counts the number of "words" in a string.