--- /dev/null
+## Copyright (c) 2011 Juan Pablo Carbajal <carbajal@ifi.uzh.ch>
+##
+## 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 3 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, see <http://www.gnu.org/licenses/>.
+
+%% -*- texinfo -*-
+%% @deftypefn {Function File} {@var{spoly} = } simplifypolygon (@var{poly})
+%% Simplify a polygon using the Ramer-Douglas-Peucker algorithm.
+%%
+%% @var{poly} is a N-by-2 matrix, each row representing a vertex.
+%%
+%% @seealso{simplifypolyline, shape2polygon}
+%% @end deftypefn
+
+function polygonsimp = simplifypolygon (polygon, varargin)
+
+ polygonsimp = simplifypolyline (polygon,varargin{:});
+
+ # Remove parrallel consecutive edges
+ PL = polygonsimp(1:end-1,:);
+ PC = polygonsimp(2:end,:);
+ PR = polygonsimp([3:end 1],:);
+ a = PL - PC;
+ b = PR - PC;
+ tf = find(isParallel(a,b))+1;
+ polygonsimp (tf,:) = [];
+
+endfunction
+
+%!test
+%! P = [0 0; 1 0; 0 1];
+%! P2 = [0 0; 0.1 0; 0.2 0; 0.25 0; 1 0; 0 1; 0 0.7; 0 0.6; 0 0.3; 0 0.1];
+%! assert(simplifypolygon (P2),P,min(P2(:))*eps)
+
+%!demo
+%!
+%! P = [0 0; 1 0; 0 1];
+%! P2 = [0 0; 0.1 0; 0.2 0; 0.25 0; 1 0; 0 1; 0 0.7; 0 0.6; 0 0.3; 0 0.1];
+%! Pr = simplifypolygon (P2);
+%!
+%! cla
+%! drawPolygon(P,'or;Reference;');
+%! hold on
+%! drawPolygon(P2,'x-b;Redundant;');
+%! drawPolygon(Pr,'*g;Simplified;');
+%! hold off
+%!
+%! % --------------------------------------------------------------------------
+%! % The two polygons describe the same figure, a triangle. Extra points are
+%! % removed form the redundant one.