main/src/georegression/geometry/UtilPoint2D_I32.java
public static Point2D_I32 mean(List<Point2D_I32> list, Point2D_I32 mean) {
		if( mean == null )
			mean = new Point2D_I32();

		int sumX = 0, sumY = 0;
		int N = list.size();

		for( int i = 0; i < N; i++ ) {
			Point2D_I32 p = list.get(i);

			sumX += p.x;
			sumY += p.y;
		}

		mean.x = sumX/N;
		mean.y = sumY/N;

		return mean;
	}
public static Point2D_I32 mean(List<Point2D_I32> list, Point2D_I32 mean) {
		if( mean == null )
			mean = new Point2D_I32();

		int sumX = 0, sumY = 0;
		int N = list.size();

		for( int i = 0; i < N; i++ ) {
			Point2D_I32 p = list.get(i);

			sumX += p.x;
			sumY += p.y;
		}

		mean.x = sumX/N;
		mean.y = sumY/N;

		return mean;
	}
Finds the point which has the mean location of all the points in the list. This is also known
as the centroid.

@param list List of points
@param mean Storage for mean point.  If null then a new instance will be declared
@return The found mean