code: private void zeroMeanWorldPoints(List<AssociatedPair> points) {
  		center.set(0,0);
  		pointsAdj.reset();
  		for (int i = 0; i < points.size(); i++) {
  			AssociatedPair pair = points.get(i);
  			Point2D_F64 p = pair.p1;
  			pointsAdj.grow().p2.set(pair.p2);
  			center.x += p.x;
  			center.y += p.y;
  		}
  		center.x /= points.size();
  		center.y /= points.size();
  		for (int i = 0; i < points.size(); i++) {
  			Point2D_F64 p = points.get(i).p1;
  			pointsAdj.get(i).p1.set( p.x - center.x, p.y - center.y);
  		}
  	}
docs: Ensure zero mean for world location. Creates a local copy of the input