--- /dev/null
+%% Copyright (c) 2011, INRA
+%% 2003-2011, 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} = } drawEllipse (@var{elli})
+%% @deftypefnx {Function File} {@var{h} = } drawEllipse (@var{xc}, @var{yc}, @var{ra}, @var{rb})
+%% @deftypefnx {Function File} {@var{h} = } drawEllipse (@var{xc}, @var{yc}, @var{ra}, @var{rb}, @var{theta})
+%% @deftypefnx {Function File} {@var{h} = } drawEllipse (@dots{}, @var{param}, @var{value})
+%% Draw an ellipse on the current axis.
+%%
+%% drawEllipse(ELLI);
+%% Draws the ellipse ELLI in the form [XC YC RA RB THETA], with center
+%% (XC, YC), with main axis of half-length RA and RB, and orientation
+%% THETA in degrees counted counter-clockwise.
+%% Puts all parameters into one single array.
+%%
+%% drawEllipse(XC, YC, RA, RB);
+%% drawEllipse(XC, YC, RA, RB, THETA);
+%% Specifies ellipse parameters as separate arguments (old syntax).
+%%
+%% drawEllipse(..., NAME, VALUE);
+%% Specifies drawing style of ellipse, see the help of plot function.
+%%
+%% H = drawEllipse(...);
+%% Also returns handles to the created line objects.
+%%
+%% -> Parameters can also be arrays. In this case, all arrays are supposed
+%% to have the same size.
+%%
+%% Example:
+%% @example
+%% % Draw an ellipse centered in [50 50], with semi major axis length of
+%% % 40, semi minor axis length of 20, and rotated by 30 degrees.
+%% figure(1); clf; hold on;
+%% drawEllipse([50 50 40 20 30]);
+%% axis equal;
+%% @end example
+%%
+%% @seealso{ellipses2d, drawCircle, drawEllipseArc, ellipseAsPolygon}
+%% @end deftypefn
+
+function varargout = drawEllipse(varargin)
+
+ % extract dawing style strings
+ styles = {};
+ for i = 1:length(varargin)
+ if ischar(varargin{i})
+ styles = varargin(i:end);
+ varargin(i:end) = [];
+ break;
+ end
+ end
+
+ % extract ellipse parameters
+ if length(varargin)==1
+ % ellipse is given in a single array
+ ellipse = varargin{1};
+ x0 = ellipse(:, 1);
+ y0 = ellipse(:, 2);
+ a = ellipse(:, 3);
+ b = ellipse(:, 4);
+ if length(ellipse)>4
+ theta = ellipse(:, 5);
+ else
+ theta = zeros(size(x0));
+ end
+
+ elseif length(varargin)>=4
+ % ellipse parameters given as separate arrays
+ x0 = varargin{1};
+ y0 = varargin{2};
+ a = varargin{3};
+ b = varargin{4};
+ if length(varargin)>4
+ theta = varargin{5};
+ else
+ theta = zeros(size(x0));
+ end
+
+ else
+ error('drawEllipse: incorrect input arguments');
+ end
+
+
+ %% Process drawing of a set of ellipses
+
+ % angular positions of vertices
+ t = linspace(0, 2*pi, 145);
+
+ % compute position of points to draw each ellipse
+ h = zeros(length(x0), 1);
+ for i = 1:length(x0)
+ % pre-compute rotation angles (given in degrees)
+ cot = cosd(theta(i));
+ sit = sind(theta(i));
+
+ % compute position of points used to draw current ellipse
+ xt = x0(i) + a(i) * cos(t) * cot - b(i) * sin(t) * sit;
+ yt = y0(i) + a(i) * cos(t) * sit + b(i) * sin(t) * cot;
+
+ % stores handle to graphic object
+ h(i) = plot(xt, yt, styles{:});
+ end
+
+ % return handles if required
+ if nargout > 0
+ varargout = {h};
+ end
+
+endfunction
+