--- /dev/null
+%% Copyright (c) 2011, INRA
+%% 2005-2011, David Legland <david.legland@grignon.inra.fr>
+%% 2011 Adapted to Octave by Juan Pablo Carbajal <carbajal@ifi.uzh.ch>
+%%
+%% All rights reserved.
+%% (simplified BSD License)
+%%
+%% Redistribution and use in source and binary forms, with or without
+%% modification, are permitted provided that the following conditions are met:
+%%
+%% 1. Redistributions of source code must retain the above copyright notice, this
+%% list of conditions and the following disclaimer.
+%%
+%% 2. Redistributions in binary form must reproduce the above copyright notice,
+%% this list of conditions and the following disclaimer in the documentation
+%% and/or other materials provided with the distribution.
+%%
+%% THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+%% AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+%% IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+%% ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
+%% LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+%% CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+%% SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+%% INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+%% CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+%% ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+%% POSSIBILITY OF SUCH DAMAGE.
+%%
+%% The views and conclusions contained in the software and documentation are
+%% those of the authors and should not be interpreted as representing official
+%% policies, either expressed or implied, of copyright holder.
+
+%% -*- texinfo -*-
+%% @deftypefn {Function File} {@var{h} =} drawCenteredEdge (@var{center}, @var{L}, @var{theta})
+%% @deftypefnx {Function File} {@var{h} =} drawCenteredEdge (@var{edge})
+%% @deftypefnx {Function File} {@var{h} =} drawCenteredEdge (@dots{}, @var{name},@var{value})
+%% Draw an edge centered on a point.
+%%
+%% drawCenteredEdge(CENTER, L, THETA)
+%% Draws an edge centered on point CENTER, with length L, and orientation
+%% THETA (given in degrees). Input arguments can also be arrays, that must
+%% all have the same number odf rows.
+%%
+%% drawCenteredEdge(EDGE)
+%% Concatenates edge parameters into a single N-by-4 array, containing:
+%% [XC YV L THETA].
+%%
+%% drawCenteredEdge(..., NAME, VALUE)
+%% Also specifies drawing options by using one or several parameter name -
+%% value pairs (see doc of plot function for details).
+%%
+%% H = drawCenteredEdge(...)
+%% Returns handle(s) to the created edges(s).
+%%
+%% @example
+%% % Draw an ellipse with its two axes
+%% figure(1); clf;
+%% center = [50 40];
+%% r1 = 30; r2 = 10;
+%% theta = 20;
+%% elli = [center r1 r2 theta];
+%% drawEllipse(elli, 'linewidth', 2);
+%% axis([0 100 0 100]); axis equal;
+%% hold on;
+%% edges = [center 2*r1 theta ; center 2*r2 theta+90];
+%% drawCenteredEdge(edges, 'linewidth', 2, 'color', 'g');
+%% @end example
+%%
+%% @seealso{edges2d, drawEdge}
+%% @end deftypefn
+
+function varargout = drawCenteredEdge(center, len, theta, varargin)
+
+ %% process input variables
+
+ if size(center, 2) == 4
+ % manage edge in single parameter
+
+ varargin = [{len, theta}, varargin];
+
+ len = center(:, 3);
+ theta = center(:, 4);
+ center = center(:, 1:2);
+
+ N = size(center, 1);
+
+ else
+ % parameters given in different arguments
+
+ % size of data
+ NP = size(center, 1);
+ NL = size(len, 1);
+ ND = size(theta, 1);
+ N = max([NP NL ND]);
+
+ % ensure all data have same size
+ if N > 1
+ if NP == 1, center = repmat(center, [N 1]); end
+ if NL == 1, len = repmat(len, [N 1]); end
+ if ND == 1, theta = repmat(theta, [N 1]); end
+ end
+
+ end
+
+ % extract drawing options
+ options = varargin(:);
+
+
+ %% Draw edges
+
+ % coordinates of center point
+ xc = center(:, 1);
+ yc = center(:, 2);
+
+ % convert angle to radians
+ theta = theta * pi / 180;
+
+ % computation shortcuts
+ cot = cos(theta);
+ sit = sin(theta);
+
+ % compute starting and ending points
+ x1 = xc - len .* cot / 2;
+ x2 = xc + len .* cot / 2;
+ y1 = yc - len .* sit / 2;
+ y2 = yc + len .* sit / 2;
+
+
+ % draw the edges
+ h = zeros(N, 1);
+ for i = 1:N
+ h(i) = plot([x1(i) x2(i)], [y1(i) y2(i)]);
+ end
+
+ % apply style to edges
+ if ~isempty(options) > 0
+ for i = 1:N
+ set(h(i), options{:});
+ end
+ end
+
+
+ %% Format output
+
+ % process output arguments
+ if nargout > 0
+ varargout = {h};
+ end
+
+endfunction
+