private void onPlotClicked(PointF point) {

    // make sure the point lies within the graph area.  we use gridrect
    // because it accounts for margins and padding as well.
    if (plot.containsPoint(point.x, point.y)) {
      Number x = plot.getXVal(point);
      Number y = plot.getYVal(point);

      selection = null;
      double xDistance = 0;
      double yDistance = 0;

      // find the closest value to the selection:
      for (SeriesBundle<XYSeries, ? extends XYSeriesFormatter> sfPair :
          plot.getRegistry().getSeriesAndFormatterList()) {
        XYSeries series = sfPair.getSeries();
        for (int i = 0; i < series.size(); i++) {
          Number thisX = series.getX(i);
          Number thisY = series.getY(i);
          if (thisX != null && thisY != null) {
            double thisXDistance = Region.measure(x, thisX).doubleValue();
            double thisYDistance = Region.measure(y, thisY).doubleValue();
            if (selection == null) {
              selection = new Pair<>(i, series);
              xDistance = thisXDistance;
              yDistance = thisYDistance;
            } else if (thisXDistance < xDistance) {
              selection = new Pair<>(i, series);
              xDistance = thisXDistance;
              yDistance = thisYDistance;
            } else if (thisXDistance == xDistance
                && thisYDistance < yDistance
                && thisY.doubleValue() >= y.doubleValue()) {
              selection = new Pair<>(i, series);
              xDistance = thisXDistance;
              yDistance = thisYDistance;
            }
          }
        }
      }

    } else {
      // if the press was outside the graph area, deselect:
      selection = null;
    }

    if (selection == null) {
      selectionWidget.setText(NO_SELECTION_TXT);
    } else {
      selectionWidget.setText(
          "Selected: "
              + selection.second.getTitle()
              + " Value: "
              + selection.second.getY(selection.first));
    }
    plot.redraw();
  }
  private void updatePlot(SeriesSize seriesSize) {

    // Remove all current series from each plot
    plot.clear();

    // Setup our Series with the selected number of elements
    series1 =
        new SimpleXYSeries(
            Arrays.asList(series1Numbers), SimpleXYSeries.ArrayFormat.Y_VALS_ONLY, "Us");
    series2 =
        new SimpleXYSeries(
            Arrays.asList(series2Numbers), SimpleXYSeries.ArrayFormat.Y_VALS_ONLY, "Them");

    plot.setDomainBoundaries(-1, series1.size(), BoundaryMode.FIXED);
    plot.setRangeUpperBoundary(
        SeriesUtils.minMax(series1, series2).getMaxY().doubleValue() + 1, BoundaryMode.FIXED);

    if (seriesSize != null) {
      switch (seriesSize) {
        case TEN:
          plot.setDomainStep(StepMode.INCREMENT_BY_VAL, 2);
          break;
        case TWENTY:
          plot.setDomainStep(StepMode.INCREMENT_BY_VAL, 4);
          break;
        case SIXTY:
          plot.setDomainStep(StepMode.INCREMENT_BY_VAL, 6);
          break;
      }
    }

    // add a new series' to the xyplot:
    if (series1CheckBox.isChecked()) plot.addSeries(series1, formatter1);
    if (series2CheckBox.isChecked()) plot.addSeries(series2, formatter2);

    // Setup the BarRenderer with our selected options
    MyBarRenderer renderer = plot.getRenderer(MyBarRenderer.class);
    renderer.setBarOrientation((BarRenderer.BarOrientation) spRenderStyle.getSelectedItem());
    final BarRenderer.BarGroupWidthMode barGroupWidthMode =
        (BarRenderer.BarGroupWidthMode) spWidthStyle.getSelectedItem();
    renderer.setBarGroupWidth(
        barGroupWidthMode,
        barGroupWidthMode == BarRenderer.BarGroupWidthMode.FIXED_WIDTH
            ? sbFixedWidth.getProgress()
            : sbVariableWidth.getProgress());

    if (BarRenderer.BarOrientation.STACKED.equals(spRenderStyle.getSelectedItem())) {
      plot.getInnerLimits().setMaxY(15);
    } else {
      plot.getInnerLimits().setMaxY(0);
    }

    plot.redraw();
  }