--- a
+++ b/combinedDeepLearningActiveContour/functions/polygonCentroid.m
@@ -0,0 +1,62 @@
+function [centroid area] = polygonCentroid(varargin)
+%POLYGONCENTROID Compute the centroid (center of mass) of a polygon
+%
+%   CENTROID = polygonCentroid(POLY)
+%   CENTROID = polygonCentroid(PTX, PTY)
+%   Computes center of mass of a polygon defined by POLY. POLY is a N-by-2
+%   array of double containing coordinates of vertices.
+%
+%   [CENTROID AREA] = polygonCentroid(POLY)
+%   Also returns the (signed) area of the polygon. 
+%
+%   Example
+%     % Draws the centroid of a paper hen
+%     x = [0 10 20  0 -10 -20 -10 -10  0];
+%     y = [0  0 10 10  20  10  10  0 -10];
+%     poly = [x' y'];
+%     centro = polygonCentroid(poly);
+%     drawPolygon(poly);
+%     hold on; axis equal;
+%     drawPoint(centro, 'bo');
+% 
+%   References
+%   algo adapted from P. Bourke web page
+%
+%   See also:
+%   polygons2d, polygonArea, drawPolygon
+%
+%   ---------
+%   author : David Legland 
+%   INRA - TPV URPOI - BIA IMASTE
+%   created the 05/05/2004.
+%
+
+% Algorithme P. Bourke, vectorized version
+
+% HISTORY
+% 2012.02.24 vectorize code
+
+
+% parse input arguments
+if nargin == 1
+    var = varargin{1};
+    px = var(:,1);
+    py = var(:,2);
+elseif nargin == 2
+    px = varargin{1};
+    py = varargin{2};
+end
+
+% vertex indices
+N = length(px);
+iNext = [2:N 1];
+
+% compute cross products
+common = px .* py(iNext) - px(iNext) .* py;
+sx = sum((px + px(iNext)) .* common);
+sy = sum((py + py(iNext)) .* common);
+
+% area and centroid
+area = sum(common) / 2;
+centroid = [sx sy] / 6 / area;
+end
\ No newline at end of file