Add a useful package (from Source forge) for octave

[CreaPhase.git] / octave_packages / fpl-1.2.0 / pdesurf.m

diff --git a/octave_packages/fpl-1.2.0/pdesurf.m b/octave_packages/fpl-1.2.0/pdesurf.m
new file mode 100644 (file)
index 0000000..ec688d2
--- /dev/null
+++ b/octave_packages/fpl-1.2.0/pdesurf.m
@@ -0,0 +1,92 @@
+##  Copyright (C) 2010  Carlo de Falco
+##
+##  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/>.
+##
+##  author: Carlo de Falco     <cdf _AT_ users.sourceforge.net>
+
+## -*- texinfo -*-
+## @deftypefn {Function File} {@var{h} =} pdesurf (@var{p}, @var{t}, @var{u})
+##
+## Plot a 3D surface given node or element data on a triangular mesh.
+## @var{p}, @var{t} are the mesh vertices and connectivity, @var{u} node or element data.
+##
+## @seealso{fpl_dx_write_field, fpl_vtk_write_field} 
+##
+## @end deftypefn
+
+function h = pdesurf (p, t, u)
+
+  ## Check input
+  if nargin!=3
+    error("pdesurf: wrong number of input parameters");
+  endif
+
+  nel = columns (t);
+  npt = columns (p);
+  if (numel (u) != npt && numel (u) != nel)
+    error("pdesurf: wrong data size");
+  endif
+
+  hs = ishold ();
+  
+### node data
+  if (numel (u) == npt)
+    ## normalize data
+    c  = colormap;
+    uc = sum (u(t(1:3, :)), 1)/3;
+    uc = floor ((rows (c)-1)*(uc - min (uc))/(max (uc) - min (uc))) + 1;
+    H = patch ('Faces', t(1:3, :)', 
+               'Vertices', [p(1,:)', p(2,:)', u], 
+               'FaceVertexCData', c(uc(:), :));
+### triangle data
+  elseif (numel (u) == nel)
+    tri = reshape (1:3*nel, 3, [])';
+    pt(:, 1) = p(1, t(1:3, :));
+    pt(:, 2) = p(2, t(1:3, :));
+    pt(:, 3) = repmat (u(:)', 3, 1)(:);
+    ## normalize data
+    c  = colormap;
+    uc = floor ((rows (c)-1)*(u - min (u))/(max (u) - min (u))) + 1;
+    H = patch ('Faces', tri, 
+               'Vertices', pt, 
+               'FaceVertexCData', c(uc(:), :), 
+               'FaceColor', 'flat');
+  endif
+  
+  if (nargout == 1)
+    h = H;
+  endif
+
+  if (hs)
+    hold on;
+  else
+    hold off;
+  endif
+
+endfunction
+
+%!demo
+%! msh = msh2m_structured_mesh ([0:.05:1], [0:.1:1], 1, 1:4, 'random');
+%! x = msh.p(1,:)'; xm = sum(x(msh.t(1:3,:)),1)/3;
+%! y = msh.p(2,:)'; ym = sum(y(msh.t(1:3,:)),1)/3;
+%! pdesurf (msh.p, msh.t, x.*(1-x).*y.*(1-y))
+%! title ('node data')
+%! view(3)
+%! figure ()
+%! pdesurf (msh.p, msh.t, xm.*(1-xm).*ym.*(1-ym))
+%! title ('element data')
+%! view(3)
\ No newline at end of file