code: public void scale(double x, double y) {
  		xx *= x;
  		xy *= x;
  		xd *= x;
  		yx *= y;
  		yy *= y;
  		yd *= y;
  	}
docs: Scales the transformation.
  
  @param x
  The scale factor in X direction.
  @param y
  The scale factor in Y direction.