code: void add(final double m, final Object pt) {
  		if (count == 0) {
  			set(m, pt);
  		} else {
  			count += 1;
  			
  			if (m != 0.0) {
  				m0 += m;
  				clusters.space.addScaled(m1, m, pt);
  				clusters.space.addScaledSqr(m2, m, pt);
  				update();
  			}
  		}
  	}
docs: Adds a point to the cluster.
  
  @param m
  the mass of the point
  @param pt
  the coordinates of the point