## Copyright (C) 2004-2011 David Legland <david.legland@grignon.inra.fr>
## Copyright (C) 2004-2011 INRA - CEPIA Nantes - MIAJ (Jouy-en-Josas)
## Copyright (C) 2012 Adapted to Octave by Juan Pablo Carbajal <carbajal@ifi.uzh.ch>
## All rights reserved.
## 
## 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 AUTHOR OR CONTRIBUTORS BE LIABLE FOR
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## DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
## SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
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## -*- texinfo -*-
## @deftypefn {Function File} {@var{len} = } edgeLength (@var{edge})
## Return length of an edge
##
##   L = edgeLength(EDGE);  
##   Returns the length of an edge, with parametric representation:
##   [x1 y1 x2 y2].
##
##   The function also works for several edges, in this case input is a
##   [N*4] array, containing parametric representation of each edge, and
##   output is a [N*1] array containing length of each edge.
##
##   @seealso{edges2d, edgeAngle}
## @end deftypefn

function len = edgeLength(varargin)

  #   TODO : specify norm (euclidian, taxi, ...).

  nargs = length(varargin);
  if nargs == 1
      edge = varargin{1};
      len = sqrt(power(edge(:,3)-edge(:,1), 2) + power(edge(:,4)-edge(:,2), 2));
  end

endfunction

