public PlaPointInt round(){
  if (is_NaN())   return new PlaPointInt();
  return new PlaPointInt(Math.round(v_x),Math.round(v_y));
}

public PlaPointInt round ( ) { if ( is_NaN ( ) ) return new PlaPointInt ( ) ; return new PlaPointInt ( Math . round ( v_x ) , Math . round ( v_y ) ) ; }
rounds the coordinates from an object of class point_double to an object of class intpoint
