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## Copyright (C) 2006,2007,2008,2009,2010,2012 Carlo de Falco, Massimiliano Culpo
##
## This file is part of:
## MSH - Meshing Software Package for Octave
##
## MSH 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.
##
## MSH 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 MSH; If not, see <http://www.gnu.org/licenses/>.
##
## author: Carlo de Falco <cdf _AT_ users.sourceforge.net>
## author: Massimiliano Culpo <culpo _AT_ users.sourceforge.net>
## -*- texinfo -*-
## @deftypefn {Function File} {[@var{mesh}]} = @
## msh3m_gmsh(@var{geometry},@var{option},@var{value},...)
## @deftypefnx {Function File}{[@var{mesh}, @var{gmsh_out}]} = msh3m_gmsh(...)
##
## Construct an unstructured tetrahedral 3D mesh making use of the free
## software gmsh.
##
## The required argument @var{geometry} is the basename of the
## @code{*.geo} file to be meshed.
##
## The optional arguments @var{option} and @var{value} identify
## respectively a gmsh option and its value. For more information
## regarding the possible option to pass, refer to gmsh manual or gmsh
## site @url{http://www.geuz.org/gmsh/}.
##
## The returned value @var{mesh} is a PDE-tool like mesh structure.
## If the function is called with two outputs @var{gmsh_out} is the verbose output
## of the gmsh subprocess.
##
## @seealso{msh3m_structured_mesh, msh2m_gmsh, msh2m_mesh_along_spline}
## @end deftypefn
function [mesh, gmsh_output] = msh3m_gmsh (geometry, varargin)
## Check input
## Number of input
if !mod(nargin,2)
warning("WRONG NUMBER OF INPUT.");
print_usage;
endif
## FIXME: add input type check?
## Build mesh
noptions = (nargin - 1) / 2; # Number of passed options
## Construct system command string
verbose = 1;
optstring = "";
for ii = 1:noptions
option = varargin{2*(ii)-1};
value = varargin{2*ii};
## Check for verbose option
if strcmp(option,"v")
verbose = value;
endif
if !ischar(value)
value = num2str(value);
endif
optstring = [optstring," -",option," ",value];
endfor
## Generate mesh using Gmsh
if (verbose)
printf("\n");
printf("Generating mesh...\n");
endif
msh_name = strcat (tmpnam (), ".msh");
fclose (fopen (msh_name, "w"));
[status, gmsh_output] = system (["gmsh -format msh2 -3 -o " msh_name optstring " " geometry ".geo 2>&1"]);
if (status)
error ("msh3m_gmsh: the gmesh subprocess exited abnormally");
endif
if (verbose)
printf("Processing gmsh data...\n");
endif
fname = tmpnam ();
fclose (fopen (strcat (fname, "_e.txt"), "w"));
e_filename = canonicalize_file_name (strcat (fname, "_e.txt"));
fclose (fopen (strcat (fname, "_p.txt"), "w"));
p_filename = canonicalize_file_name (strcat (fname, "_p.txt"));
fclose (fopen (strcat (fname, "_t.txt"), "w"));
t_filename = canonicalize_file_name (strcat (fname, "_t.txt"));
fclose (fopen (strcat (fname, "_s.txt"), "w"));
s_filename = canonicalize_file_name (strcat (fname, "_s.txt"));
## Points
com_p = sprintf ("awk '/\\$Nodes/,/\\$EndNodes/ {print $2, $3, $4 > ""%s""}' ", p_filename);
## Surface edges
com_e = sprintf ("awk '/\\$Elements/,/\\$EndElements/ {n=3+$3; if ($2 == ""2"") print $(n+1), $(n+2), $(n+3), $5 > ""%s""}' ", e_filename);
## Tetrahedra
com_t = sprintf ("awk '/\\$Elements/,/\\$EndElements/ {n=3+$3; if ($2 == ""4"") print $(n+1), $(n+2), $(n+3), $(n+4), $5 > ""%s""}' ", t_filename);
## Side edges
com_s = sprintf ("awk '/\\$Elements/,/\\$EndElements/ {n=3+$3; if ($2 == ""1"") print $(n+2), $(n+2), $5 > ""%s""}' ", s_filename);
command = [com_p, msh_name, ";"];
command = [command, com_e, msh_name, ";"];
command = [command, com_t, msh_name, ";"];
command = [command, com_s, msh_name];
system (command);
## Create PDE-tool like structure
if (verbose)
printf("Creating PDE-tool like mesh...\n");
endif
## Mesh-points
p = load(p_filename)';
## Mesh side-edges
s = load(s_filename)';
## Mesh surface-edges
tmp = load(e_filename)';
be = zeros(10,columns(tmp));
be([1,2,3,10],:) = tmp;
## Mesh tetrahedra
t = load(t_filename)';
## Remove hanging nodes
if (verbose)
printf("Check for hanging nodes...\n");
endif
nnodes = columns(p);
in_msh = intersect( 1:nnodes , t(1:4,:) );
if length(in_msh) != nnodes
new_num(in_msh) = [1:length(in_msh)];
t(1:4,:) = new_num(t(1:4,:));
be(1:3,:) = new_num(be(1:3,:));
p = p(:,in_msh);
endif
mesh = struct("p",p,"s",s,"e",be,"t",t);
if (verbose)
printf("Deleting temporary files...\n");
endif
unlink (p_filename);
unlink (e_filename);
unlink (t_filename);
unlink (s_filename);
unlink (msh_name);
endfunction
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