question: public void point ( double x , double y ) { double xs = scaleX ( x ) ; double ys = scaleY ( y ) ; double r = penRadius ; if ( r <= 1 ) pixel ( x , y ) ; else offscreen . fill ( new Ellipse2D . Double ( xs - r / 2 , ys - r / 2 , r , r ) ) ; draw ( ) ; }
target:  Draws a point at (x, y).