public static JPanel createDemoPanel() {
// create plot...
NumberAxis xAxis = new NumberAxis("X");
xAxis.setAutoRangeIncludesZero(false);
NumberAxis yAxis = new NumberAxis("Y");
yAxis.setAutoRangeIncludesZero(false);
XYSplineRenderer renderer1 = new XYSplineRenderer();
renderer1.setDefaultShapesVisible(false);
XYPlot plot = new XYPlot(createSampleData(), xAxis, yAxis, renderer1);
plot.setBackgroundPaint(Color.LIGHT_GRAY);
plot.setDomainGridlinePaint(Color.WHITE);
plot.setRangeGridlinePaint(Color.WHITE);
plot.setAxisOffset(new RectangleInsets(4, 4, 4, 4));
// create and return the chart panel...
JFreeChart chart = new JFreeChart("XYSplineRenderer",
JFreeChart.DEFAULT_TITLE_FONT, plot, true);
ChartUtils.applyCurrentTheme(chart);
ChartPanel chartPanel = new ChartPanel(chart);
return chartPanel;
}