/** test BarbManipulationRendererJ3D */
  public static void main(String args[]) throws VisADException, RemoteException {

    System.out.println("BMR.main()");

    // construct RealTypes for wind record components
    RealType lat = RealType.Latitude;
    RealType lon = RealType.Longitude;
    RealType windx = RealType.getRealType("windx", CommonUnit.meterPerSecond);
    RealType windy = RealType.getRealType("windy", CommonUnit.meterPerSecond);
    RealType red = RealType.getRealType("red");
    RealType green = RealType.getRealType("green");

    // EarthVectorType extends RealTupleType and says that its
    // components are vectors in m/s with components parallel
    // to Longitude (positive east) and Latitude (positive north)
    EarthVectorType windxy = new EarthVectorType(windx, windy);

    RealType wind_dir = RealType.getRealType("wind_dir", CommonUnit.degree);
    RealType wind_speed = RealType.getRealType("wind_speed", CommonUnit.meterPerSecond);
    RealTupleType windds = null;
    if (args.length > 0) {
      System.out.println("polar winds");
      windds =
          new RealTupleType(
              new RealType[] {wind_dir, wind_speed}, new WindPolarCoordinateSystem(windxy), null);
    }

    // construct Java3D display and mappings that govern
    // how wind records are displayed
    DisplayImpl display = new DisplayImplJ3D("display1", new TwoDDisplayRendererJ3D());
    ScalarMap lonmap = new ScalarMap(lon, Display.XAxis);
    display.addMap(lonmap);
    ScalarMap latmap = new ScalarMap(lat, Display.YAxis);
    display.addMap(latmap);

    FlowControl flow_control;
    if (args.length > 0) {
      ScalarMap winds_map = new ScalarMap(wind_speed, Display.Flow1Radial);
      display.addMap(winds_map);
      winds_map.setRange(0.0, 1.0); // do this for barb rendering
      ScalarMap windd_map = new ScalarMap(wind_dir, Display.Flow1Azimuth);
      display.addMap(windd_map);
      windd_map.setRange(0.0, 360.0); // do this for barb rendering
      flow_control = (FlowControl) windd_map.getControl();
      flow_control.setFlowScale(0.15f); // this controls size of barbs
    } else {
      ScalarMap windx_map = new ScalarMap(windx, Display.Flow1X);
      display.addMap(windx_map);
      windx_map.setRange(-1.0, 1.0); // do this for barb rendering
      ScalarMap windy_map = new ScalarMap(windy, Display.Flow1Y);
      display.addMap(windy_map);
      windy_map.setRange(-1.0, 1.0); // do this for barb rendering
      flow_control = (FlowControl) windy_map.getControl();
      flow_control.setFlowScale(0.15f); // this controls size of barbs
    }

    display.addMap(new ScalarMap(red, Display.Red));
    display.addMap(new ScalarMap(green, Display.Green));
    display.addMap(new ConstantMap(1.0, Display.Blue));

    DataReferenceImpl[] refs = new DataReferenceImpl[N * N];
    int k = 0;
    // create an array of N by N winds
    for (int i = 0; i < N; i++) {
      for (int j = 0; j < N; j++) {
        double u = 2.0 * i / (N - 1.0) - 1.0;
        double v = 2.0 * j / (N - 1.0) - 1.0;

        // each wind record is a Tuple (lon, lat, (windx, windy), red, green)
        // set colors by wind components, just for grins
        Tuple tuple;
        double fx = 30.0 * u;
        double fy = 30.0 * v;
        if (args.length > 0) {
          double fd = Data.RADIANS_TO_DEGREES * Math.atan2(-fx, -fy);
          double fs = Math.sqrt(fx * fx + fy * fy);
          tuple =
              new Tuple(
                  new Data[] {
                    new Real(lon, 10.0 * u),
                    new Real(lat, 10.0 * v - 40.0),
                    new RealTuple(windds, new double[] {fd, fs}),
                    new Real(red, u),
                    new Real(green, v)
                  });
        } else {
          tuple =
              new Tuple(
                  new Data[] {
                    new Real(lon, 10.0 * u),
                    new Real(lat, 10.0 * v - 40.0),
                    new RealTuple(windxy, new double[] {fx, fy}),
                    new Real(red, u),
                    new Real(green, v)
                  });
        }

        // construct reference for wind record
        refs[k] = new DataReferenceImpl("ref_" + k);
        refs[k].setData(tuple);

        // link wind record to display via BarbManipulationRendererJ3D
        // so user can change barb by dragging it
        // drag with right mouse button and shift to change direction
        // drag with right mouse button and no shift to change speed
        BarbManipulationRendererJ3D renderer = new BarbManipulationRendererJ3D();
        renderer.setKnotsConvert(true);
        display.addReferences(renderer, refs[k]);

        // link wind record to a CellImpl that will listen for changes
        // and print them
        WindGetterJ3D cell = new WindGetterJ3D(flow_control, refs[k]);
        cell.addReference(refs[k]);

        k++;
      }
    }

    // instead of linking the wind record "DataReferenceImpl refs" to
    // the WindGetterJ3Ds, you can have some user interface event (e.g.,
    // the user clicks on "DONE") trigger code that does a getData() on
    // all the refs and stores the records in a file.

    // create JFrame (i.e., a window) for display and slider
    JFrame frame = new JFrame("test BarbManipulationRendererJ3D");
    frame.addWindowListener(
        new WindowAdapter() {
          public void windowClosing(WindowEvent e) {
            System.exit(0);
          }
        });

    // create JPanel in JFrame
    JPanel panel = new JPanel();
    panel.setLayout(new BoxLayout(panel, BoxLayout.Y_AXIS));
    panel.setAlignmentY(JPanel.TOP_ALIGNMENT);
    panel.setAlignmentX(JPanel.LEFT_ALIGNMENT);
    frame.getContentPane().add(panel);

    // add display to JPanel
    panel.add(display.getComponent());

    // set size of JFrame and make it visible
    frame.setSize(500, 500);
    frame.setVisible(true);
  }