JavaFX 2.x: настройки осей X и Y

Мой код ниже отображает 2 линейных графика XY в ВЕРТИКАЛЬНОЙ разделенной SplitPane.

Мой вопрос:

Я хотел бы иметь обе оси Y и только одну ось X внизу (ось X только на нижнем графике)

public class XyChartInSplit extends Application {
SplitPane               splitPane1 = null;
@Override
public void start(Stage stage) {
   stage.setTitle("Line plot");

   final CategoryAxis xAxis1 = new CategoryAxis();
   final NumberAxis yAxis1 = new NumberAxis(1, 21,0.1);

   yAxis1.setTickUnit(1);
   yAxis1.setPrefWidth(35);
   yAxis1.setMinorTickCount(10);

   yAxis1.setTickLabelFormatter(new NumberAxis.DefaultFormatter(yAxis1){
        @Override
    public String toString(Number object){
            String label;
            label = String.format("%7.2f", object.floatValue());
            return label;
    }
});
  final LineChart<String, Number>lineChart1 = new LineChart<String, Number>(xAxis1, yAxis1);

   lineChart1.setCreateSymbols(false);
   lineChart1.setAlternativeRowFillVisible(false);
   lineChart1.setLegendVisible(false);
   lineChart1.setAnimated(false);

   XYChart.Series series1 = new XYChart.Series();

    series1.getData().add(new XYChart.Data("Jan", 1));
    series1.getData().add(new XYChart.Data("Feb", 2));
    series1.getData().add(new XYChart.Data("Mar", 1.5));
    series1.getData().add(new XYChart.Data("Apr", 3));
    series1.getData().add(new XYChart.Data("May", 2.5));
    series1.getData().add(new XYChart.Data("Jun", 5));
    series1.getData().add(new XYChart.Data("Jul", 4));
    series1.getData().add(new XYChart.Data("Aug", 8));
    series1.getData().add(new XYChart.Data("Sep", 6.5));
    series1.getData().add(new XYChart.Data("Oct", 13));
    series1.getData().add(new XYChart.Data("Nov", 10));
    series1.getData().add(new XYChart.Data("Dec", 20));

    //final BorderPane pane1 = new BorderPane();
    //pane1.setCenter(lineChart1);                          
    lineChart1.getData().addAll(series1); 

    final CategoryAxis xAxis2 = new CategoryAxis();
   final NumberAxis yAxis2 = new NumberAxis(1, 21,0.1);

   yAxis2.setTickUnit(1);
   yAxis2.setPrefWidth(35);
   yAxis2.setMinorTickCount(10);

   yAxis2.setTickLabelFormatter(new NumberAxis.DefaultFormatter(yAxis2){
        @Override
    public String toString(Number object){
            String label;
            label = String.format("%7.2f", object.floatValue());
            return label;
    }
});

    final LineChart<String, Number>lineChart2 = new LineChart<String, Number>(xAxis2, yAxis2);

   lineChart2.setCreateSymbols(false);
   lineChart2.setAlternativeRowFillVisible(false);
   lineChart2.setLegendVisible(false);
   lineChart2.setAnimated(false);

    XYChart.Series series2 = new XYChart.Series();

    series2.getData().add(new XYChart.Data("Jan", 1));
    series2.getData().add(new XYChart.Data("Feb", 3));
    series2.getData().add(new XYChart.Data("Mar", 1.5));
    series2.getData().add(new XYChart.Data("Apr", 3));
    series2.getData().add(new XYChart.Data("May", 4.5));
    series2.getData().add(new XYChart.Data("Jun", 5));
    series2.getData().add(new XYChart.Data("Jul", 4));
    series2.getData().add(new XYChart.Data("Aug", 8));
    series2.getData().add(new XYChart.Data("Sep", 16.5));
    series2.getData().add(new XYChart.Data("Oct", 13.9));
    series2.getData().add(new XYChart.Data("Nov", 17));
    series2.getData().add(new XYChart.Data("Dec", 20));

   // final BorderPane pane2 = new BorderPane();
    //pane2.setCenter(lineChart2);          

    lineChart2.getData().addAll(series2);

    splitPane1 = new SplitPane();                                
    splitPane1.setOrientation(Orientation.VERTICAL);
    splitPane1.getItems().addAll(lineChart1);
    splitPane1.setDividerPosition(0, 1);

    Scene scene = new Scene(splitPane1, 800, 600);

     Platform.runLater(new Runnable() {
         @Override
         public void run() {
             double percSplit;

            splitPane1.getItems().addAll(lineChart2);

            ObservableList<SplitPane.Divider> splitDiv =  splitPane1.getDividers();

            percSplit = 1/(double)(splitDiv.size()+1);
            for (int i = 0; i< splitDiv.size(); i++) {                        
                splitPane1.setDividerPosition(i, percSplit);
                percSplit += 1/(double)(splitDiv.size()+1);
                }
         }
     });

    stage.setScene(scene);
    stage.show();
}

public static void main(String[] args) {
    launch(args);
}   

}