Add a useful package (from Source forge) for octave

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

diff --git a/octave_packages/geometry-1.5.0/geom2d/drawParabola.m b/octave_packages/geometry-1.5.0/geom2d/drawParabola.m
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+%% Copyright (c) 2011, INRA
+%% 2006-2011, 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} = } drawParabola (@var{parabola})
+%% @deftypefnx {Function File} {@var{h} = } drawParabola (@var{parabola}, @var{t})
+%% @deftypefnx {Function File} {@var{h} = } drawParabola (@dots{}, @var{param}, @var{value})
+%% Draw a parabola on the current axis.
+%%
+%%   drawParabola(PARABOLA);
+%%   Draws a vertical parabola, defined by its vertex and its parameter.
+%%   Such a parabola admits a vertical axis of symetry.
+%%
+%%   The algebraic equation of parabola is given by:
+%%      (Y - YV) = A * (X - VX)^2
+%%   Where XV and YV are vertex coordinates and A is parabola parameter.
+%%
+%%   A parametric equation of parabola is given by:
+%%      x(t) = t + VX;
+%%      y(t) = A * t^2 + VY;
+%%
+%%   PARABOLA can also be defined by [XV YV A THETA], with theta being the
+%%   angle of rotation of the parabola (in degrees and Counter-Clockwise).
+%%
+%%   drawParabola(PARABOLA, T);
+%%   Specifies which range of 't' are used for drawing parabola. If T is an
+%%   array with only two values, the first and the last values are used as
+%%   interval bounds, and several values are distributed within this
+%%   interval.
+%%
+%%   drawParabola(..., NAME, VALUE);
+%%   Can specify one or several graphical options using parameter name-value
+%%   pairs.
+%%
+%%   H = drawParabola(...);
+%%   Returns an handle to the created graphical object.
+%%
+%%
+%%   Example:
+%%   @example
+%%   figure(1); clf; hold on;
+%%   drawParabola([50 50 .2 30]);
+%%   drawParabola([50 50 .2 30], [-1 1], 'color', 'r', 'linewidth', 2);
+%%   axis equal;
+%% @end example
+%%
+%%   @seealso{drawCircle, drawEllipse}
+%% @end deftypefn
+
+function varargout = drawParabola(varargin)
+
+  % Extract parabola
+  if nargin<1
+      error('geom2d:IllegalArgument', ...
+          'Please specify parabola representation');
+  end
+
+  % input parabola is given as a packed array
+  parabola = varargin{1};
+  varargin(1) = [];
+  x0 = parabola(:,1);
+  y0 = parabola(:,2);
+  a  = parabola(:,3);
+
+  if size(parabola, 2)>3
+      theta = parabola(:, 4);
+  else
+      theta = zeros(length(a), 1);
+  end
+
+  % extract parametrisation bounds
+  bounds = [-100 100];
+  if ~isempty(varargin)
+      var = varargin{1};
+      if isnumeric(var)
+          bounds = var;
+          varargin(1) = [];
+      end
+  end
+
+  % create parametrisation
+  if length(bounds)>2
+      t = bounds;
+  else
+      t = linspace(bounds(1), bounds(end), 100);
+  end
+
+  % create handle array (in the case of several parabola)
+  h = zeros(size(x0));
+
+  % draw each parabola
+  for i=1:length(x0)
+      % compute transformation
+      trans = ...
+          createTranslation(x0(i), y0(i)) * ...
+          createRotation(deg2rad(theta(i))) * ...
+          createScaling(1, a);
+      
+         % compute points on the parabola
+      [xt yt] = transformPoint(t(:), t(:).^2, trans);
+
+      % draw it
+      h(i) = plot(xt, yt, varargin{:});
+  end
+
+  % process output arguments
+  if nargout>0
+      varargout{1}=h;
+  end
+
+endfunction
+