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, polygonSecondAreaMoments, drawPolygon

Package: matgeom