--- /dev/null
+## Copyright (C) 2004-2008 Carlo de Falco, Massimiliano Culpo
+##
+## This file is part of
+##
+## FPL - Fem PLotting package for octave
+##
+## FPL 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.
+##
+## FPL 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 FPL; If not, see <http://www.gnu.org/licenses/>.
+##
+##
+## AUTHORS:
+## Carlo de Falco <cdf _AT_ users.sourceforge.net>
+##
+## Culpo Massimiliano
+## Bergische Universitaet Wuppertal
+## Fachbereich C - Mathematik und Naturwissenschaften
+## Arbeitsgruppe fuer Angewandte MathematD-42119 Wuppertal Gaussstr. 20
+## D-42119 Wuppertal, Germany
+
+## -*- texinfo -*-
+## @deftypefn {Function File} {} FPL2pdequiver (@var{mesh}, @
+## @var{vx}, @var{vy}, [ @var{property}, @var{value} ...])
+##
+## Plots the 2D vector field @var{vx}, @var{vy}
+## defined on the triangulation @var{mesh} using opendx.
+##
+## Options (default values):
+## @var{sample_density} (100)
+##
+## @seealso{FPL2pdesurf, FPL2ptcsurf, FPL2ptcquiver}
+## @end deftypefn
+
+function FPL2pdequiver(mesh,vecfieldx,vecfieldy,varargin);
+
+ sample_density = "100";
+
+ if( (nargin >= 3) && (rem(nargin,2)==1) )
+ for ii=1:2:length(varargin)
+ [ varargin{ii} " = " varargin{ii+1} ";" ]
+ eval([ varargin{ii} " = """ varargin{ii+1} """;" ]);
+ endfor
+ else
+ error(["wrong number of parameters " num2str (nargin)])
+ endif
+
+ JX = sum(vecfieldx,1)'/3;
+ JY = sum(vecfieldy,1)'/3;
+
+ dataname = mktemp("/tmp",".dx");
+ scriptname = mktemp("/tmp",".net");
+
+ FPL2dxoutputdata(dataname,mesh.p,mesh.t,[ JX JY],'J',1,2,1);
+
+ showmesh = file_in_path(path,"FPL2pdequiver.net");
+
+ system (["cp " showmesh " " scriptname]);
+ system (["sed -i \'s|__FILE__DX__|" dataname "|g\' " scriptname]);
+ system (["sed -i \'s|__SAMPLE__DENSITY__|" sample_density "|g\' " scriptname]);
+
+ command = ["dx -noConfirmedQuit -program " scriptname " -execute -image >& /dev/null & "];
+
+ system(command);
+
+
+endfunction
+
+function filename = mktemp (direct,ext);
+
+ if (~exist(direct,"dir"))
+ error("trying to save temporary file to non existing directory")
+ endif
+
+ done=false;
+
+ while ~done
+ filename = [direct,"/FPL.",num2str(floor(rand*1e7)),ext];
+ if ~exist(filename,"file")
+ done =true;
+ endif
+ endwhile
+
+endfunction