Java: Drawing charts it's easy

Recently I need to draw chart, and after short search I found great library JFreeChart thats provide drawing and saving charts to file


Here is the code sample:
import javax.swing.JFrame;
import org.jfree.chart.ChartFactory;
import org.jfree.chart.ChartPanel;
import org.jfree.chart.JFreeChart;
import org.jfree.chart.plot.PlotOrientation;
import org.jfree.data.xy.XYDataset;
import org.jfree.data.xy.XYSeries;
import org.jfree.data.xy.XYSeriesCollection;

public class MyChart {
public static void main(String[] args) {
XYSeries series = new XYSeries("cos(a)");

//calculating points
for(float i = -10; i < 10; i+=0.1){
series.add(i, Math.cos(i));
}

XYDataset xyDataset = new XYSeriesCollection(series);

//creating chart
JFreeChart chart = ChartFactory
.createXYLineChart("y = cos(x)", "x", "y",
xyDataset,
PlotOrientation.VERTICAL,
true, true, true);
JFrame frame =
new JFrame("Chart");

//adding chart to the frame
frame.getContentPane()
.add(new ChartPanel(chart));
frame.setSize(400,300);
frame.show();
}
}