public void doAction() throws VisADException, RemoteException {
   Tuple tuple = (Tuple) ref.getData();
   float lon = (float) ((Real) tuple.getComponent(0)).getValue();
   float lat = (float) ((Real) tuple.getComponent(1)).getValue();
   RealTuple wind = (RealTuple) tuple.getComponent(2);
   float windx = (float) ((Real) wind.getComponent(0)).getValue();
   float windy = (float) ((Real) wind.getComponent(1)).getValue();
   System.out.println("wind = (" + windx + ", " + windy + ") at (" + +lat + ", " + lon + ")");
   /* a testing hack
       count--;
       if (count < 0) {
         count = 20;
         scale = 0.15f * 0.3f / scale;
         flow_control.setFlowScale(scale);
       }
   */
 }