1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81
|
## Copyright (C) 2024 David Legland
## 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
## 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 the copyright holders.
function len = polygonLength(poly, varargin)
%POLYGONLENGTH Perimeter of a polygon.
%
% L = polygonLength(POLYGON);
% Computes the boundary length of a polygon. POLYGON is given by a N-by-2
% array of vertices.
%
% Example
% % Perimeter of a circle approximation
% poly = circleToPolygon([0 0 1], 200);
% polygonLength(poly)
% ans =
% 6.2829
%
% See also
% polygons2d, polygonCentroid, polygonArea, drawPolygon, polylineLength
%
% ------
% Author: David Legland
% E-mail: david.legland@inrae.fr
% Created: 2005-05-11
% Copyright 2005-2023 INRA - TPV URPOI - BIA IMASTE
% If first argument is a cell array, this is a multi-polygon, and we simply
% add the lengths of individual polygons
if iscell(poly)
len = 0;
for i = 1:length(poly)
len = len + polygonLength(poly{i});
end
return;
end
% case of a polygon given as two coordinate arrays
if nargin == 2
poly = [poly varargin{1}];
end
% check there are enough points
if size(poly, 1) < 2
len = 0;
return;
end
% compute length
if size(poly, 2) == 2
% polygon in dimension 2 (classical case)
dp = diff(poly([1:end 1], :), 1, 1);
len = sum(hypot(dp(:, 1), dp(:, 2)));
else
% polygon of larger dimension
len = sum(sqrt(sum(diff(poly([2:end 1], :), 1, 1).^2, 2)));
end
|