main/src/georegression/geometry/UtilPoint2D_F64.java
public static Point2D_F64 mean( Point2D_F64[] list , int offset , int length , Point2D_F64 mean ) {
		if( mean == null )
			mean = new Point2D_F64();

		double x = 0;
		double y = 0;

		for (int i = 0; i < length; i++) {
			Point2D_F64 p = list[offset+i];
			x += p.getX();
			y += p.getY();
		}

		x /= length;
		y /= length;

		mean.set(x, y);
		return mean;
	}
public static Point2D_F64 mean( Point2D_F64[] list , int offset , int length , Point2D_F64 mean ) {
		if( mean == null )
			mean = new Point2D_F64();

		double x = 0;
		double y = 0;

		for (int i = 0; i < length; i++) {
			Point2D_F64 p = list[offset+i];
			x += p.getX();
			y += p.getY();
		}

		x /= length;
		y /= length;

		mean.set(x, y);
		return mean;
	}
Finds the point which has the mean location of all the points in the array. This is also known
as the centroid.

@param list List of points
@param offset First index in list
@param length Length of elements in list
@param mean Storage for mean point.  If null then a new instance will be declared
@return The found mean