Add a useful package (from Source forge) for octave

[CreaPhase.git] / octave_packages / geometry-1.5.0 / geom2d / createCircle.m

diff --git a/octave_packages/geometry-1.5.0/geom2d/createCircle.m b/octave_packages/geometry-1.5.0/geom2d/createCircle.m
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+++ b/octave_packages/geometry-1.5.0/geom2d/createCircle.m
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+%% 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{circle} = } createCircle (@var{p1}, @var{p2}, @var{p3})
+%% @deftypefnx {Function File} {@var{circle} = } createCircle (@var{p1}, @var{p2})
+%% Create a circle from 2 or 3 points.
+%%
+%%   Creates the circle passing through the 3 given points.
+%%   C is a 1x3 array of the form: [XC YX R].
+%%
+%% When two points are given, creates the circle whith center @var{p1} and passing
+%% throuh the point @var{p2}.
+%%
+%%   Works also when input are point arrays the same size, in this case the
+%%   result has as many lines as the point arrays.
+%%
+%%   Example
+%%
+%% @example
+%%   % Draw a circle passing through 3 points.
+%%     p1 = [10 15];
+%%     p2 = [15 20];
+%%     p3 = [10 25];
+%%     circle = createCircle(p1, p2, p3);
+%%     figure; hold on; axis equal; axis([0 50 0 50]);
+%%     drawPoint([p1 ; p2; p3]);
+%%     drawCircle(circle);
+%% @end example
+%%
+%%   @seealso{circles2d, createDirectedCircle}
+%% @end deftypefn
+
+function circle = createCircle(varargin)
+
+  if nargin == 2
+      % inputs are the center and a point on the circle
+      p1 = varargin{1};
+      p2 = varargin{2};
+      x0 = p1(:,1);
+      y0 = p1(:,2);
+      r = hypot((p2(:,1)-x0), (p2(:,2)-y0));
+
+  elseif nargin == 3
+      % inputs are three points on the circle
+      p1 = varargin{1};
+      p2 = varargin{2};
+      p3 = varargin{3};
+
+      % compute circle center
+      line1 = medianLine(p1, p2);
+      line2 = medianLine(p1, p3);
+      point = intersectLines(line1, line2);
+      x0 = point(:, 1);
+      y0 = point(:, 2);
+
+      % circle radius
+      r = hypot((p1(:,1)-x0), (p1(:,2)-y0));
+  end
+
+  % create array for returning result
+  circle = [x0 y0 r];
+
+endfunction
+
+%!shared privpath
+%! privpath = [fileparts(which('geom2d_Contents')) filesep() 'private'];
+
+%!test
+%!  addpath (privpath,'-end')
+%!  p1 = [10 15];
+%!  p2 = [15 20];
+%!  p3 = [10 25];
+%!  exp = [10 20 5];
+%!  circle = createCircle(p1, p2, p3);
+%!  assertEqual(exp, circle);
+%!  circle = createCircle(p3, p1, p2);
+%!  assertEqual(exp, circle);
+%!  circle = createCircle(p2, p3, p1);
+%!  assertEqual(exp, circle);
+%!  rmpath (privpath);
+
+%!test
+%!  addpath (privpath,'-end')
+%!  p1 = [10 15];
+%!  p2 = [15 20];
+%!  p3 = [10 25];
+%!  exp = [10 20 5];
+%!  p1 = [p1; p1+10; p1+20; p1-5];
+%!  p2 = [p2; p2+10; p2+20; p2-5];
+%!  p3 = [p3; p3+10; p3+20; p3-5];
+%!  exp = repmat(exp, 4, 1) + [0 0 0;10 10 0;20 20 0;-5 -5 0];
+%!  circle = createCircle(p1, p2, p3);
+%!  assertEqual(exp, circle);
+%!  circle = createCircle(p3, p1, p2);
+%!  assertEqual(exp, circle);
+%!  circle = createCircle(p2, p3, p1);
+%!  assertEqual(exp, circle);
+%!  rmpath (privpath);