JFreeChart- Bubble Chart

A bubble chart represents information in a three-dimensional manner. This chart is a variation of a scatter chart(XY chart) in which the data points are replaced by bubbles, and an additional dimension (z-values) of the data is represented in the size of the bubbles.

The following images show some of the demo versions of Bubble chart incorporated in JFreeChart library:

Bubble Chart Demo 1:

Bubble Chart Demo 2:

Bubble chart example:

Let us consider the following sample data for a bubble chart.

COUNTRY	Cars (in Million) X-Value	Buses (in Million) Y-Value	Trucks (in Million) Z-Value
India	40	65	70
U.S.A	30	20	50
China	80	50	80
Japan	11	50	20

The following codes create a Bubble chart from the above sample data:

BubbleChartExample.java

import java.text.DecimalFormat;
import javax.swing.JFrame;
import javax.swing.SwingUtilities;
import javax.swing.WindowConstants;
import org.jfree.chart.ChartFactory;
import org.jfree.chart.ChartPanel;
import org.jfree.chart.JFreeChart;
import org.jfree.chart.axis.NumberAxis;
import org.jfree.chart.labels.BubbleXYItemLabelGenerator;
import org.jfree.chart.plot.XYPlot;
import org.jfree.chart.renderer.xy.XYBubbleRenderer;
import org.jfree.data.xy.DefaultXYZDataset;
import org.jfree.data.xy.XYZDataset;

public class BubbleChartExample extends JFrame {

  private static final long serialVersionUID = 1L;

  public BubbleChartExample(String title) {
    super(title);

    // Create dataset
    XYZDataset dataset = createDataset();

    // Create chart
    JFreeChart chart = ChartFactory.createBubbleChart(
        "Country(Cars, Buses, Trucks)", 
        "X-Values", 
        "Y-Values", dataset);

    
    // Set range for X-Axis
    XYPlot plot = chart.getXYPlot();
    NumberAxis domain = (NumberAxis) plot.getDomainAxis();
    domain.setRange(0, 100);

    // Set range for Y-Axis
    NumberAxis range = (NumberAxis) plot.getRangeAxis();
    range.setRange(0, 100);
    
    //Format label
    XYBubbleRenderer renderer=(XYBubbleRenderer)plot.getRenderer();
    BubbleXYItemLabelGenerator generator=new BubbleXYItemLabelGenerator(
        " {0}:({1},{2},{3}) ",new DecimalFormat("0"),
        new DecimalFormat("0"),
        new DecimalFormat("0"));
    renderer.setBaseItemLabelGenerator(generator);
    renderer.setBaseItemLabelsVisible(true);
    
    // Create Panel
    ChartPanel panel = new ChartPanel(chart);
    setContentPane(panel);
  }
  private XYZDataset createDataset() {
    DefaultXYZDataset dataset = new DefaultXYZDataset();

    dataset.addSeries("INDIA", new double[][] { 
      { 40 }, // X-Value 
      { 65 }, // Y-Value 
      { 70 }  // Z-Value 
     });
    dataset.addSeries("USA", new double[][] { { 30 }, { 20 }, { 50 } });
    dataset.addSeries("CHINA", new double[][] { { 80 }, { 50 }, { 80 } });
    dataset.addSeries("JAPAN", new double[][] { { 11 }, { 50 }, { 20 } });

    return dataset;
  }

  public static void main(String[] args) {
    SwingUtilities.invokeLater(() -> {
      BubbleChartExample example = new BubbleChartExample("Bubble Chart Example");
      example.setSize(800, 400);
      example.setLocationRelativeTo(null);
      example.setDefaultCloseOperation(WindowConstants.EXIT_ON_CLOSE);
      example.setVisible(true);
    });
  }
}

Output: