ChartDirector 6.1 (Java Edition)

Bubble Chart




This example demonstrates how to create a bubble chart.

In ChartDirector, a bubble chart can be created as a scatter layer with circles as symbols using XYChart.addScatterLayer. The sizes of the symbols are then controlled by another data series (z data) using LineLayer.setSymbolScale. This creates circles of different sizes.

By default, ChartDirector handles z data using pixel units. That means a z value of 50 will result in a symbol size of 50 pixels. If your z data are too small or too large, you may re-scale them using ArrayMath.mul before passing them to LineLayer.setSymbolScale.

ChartDirector also supports handling the z data using the same scale as the y (or x) axis by supplying additional arguments to LineLayer.setSymbolScale. This is useful if the symbol sizes reflect some features of the y (or x) data, such as the standard deviation or confidence of the y (or x) value.

Source Code Listing

[JSP Version] jspdemo/bubble.jsp
<%@page import="ChartDirector.*" %>
<%
// The XYZ points for the bubble chart
double[] dataX0 = {150, 300, 1000, 1700};
double[] dataY0 = {12, 60, 25, 65};
double[] dataZ0 = {20, 50, 50, 85};

double[] dataX1 = {500, 1000, 1300};
double[] dataY1 = {35, 50, 75};
double[] dataZ1 = {30, 55, 95};

// Create a XYChart object of size 450 x 420 pixels
XYChart c = new XYChart(450, 420);

// Set the plotarea at (55, 65) and of size 350 x 300 pixels, with a light grey border (0xc0c0c0).
// Turn on both horizontal and vertical grid lines with light grey color (0xc0c0c0)
c.setPlotArea(55, 65, 350, 300, -1, -1, 0xc0c0c0, 0xc0c0c0, -1);

// Add a legend box at (50, 30) (top of the chart) with horizontal layout. Use 12pt Times Bold
// Italic font. Set the background and border color to Transparent.
c.addLegend(50, 30, false, "Times New Roman Bold Italic", 12).setBackground(Chart.Transparent);

// Add a title to the chart using 18pt Times Bold Itatic font.
c.addTitle("Product Comparison Chart", "Times New Roman Bold Italic", 18);

// Add a title to the y axis using 12pt Arial Bold Italic font
c.yAxis().setTitle("Capacity (tons)", "Arial Bold Italic", 12);

// Add a title to the x axis using 12pt Arial Bold Italic font
c.xAxis().setTitle("Range (miles)", "Arial Bold Italic", 12);

// Set the axes line width to 3 pixels
c.xAxis().setWidth(3);
c.yAxis().setWidth(3);

// Add (dataX0, dataY0) as a scatter layer with semi-transparent red (0x80ff3333) circle symbols,
// where the circle size is modulated by dataZ0. This creates a bubble effect.
c.addScatterLayer(dataX0, dataY0, "Technology AAA", Chart.CircleSymbol, 9, 0x80ff3333, 0x80ff3333
    ).setSymbolScale(dataZ0);

// Add (dataX1, dataY1) as a scatter layer with semi-transparent green (0x803333ff) circle symbols,
// where the circle size is modulated by dataZ1. This creates a bubble effect.
c.addScatterLayer(dataX1, dataY1, "Technology BBB", Chart.CircleSymbol, 9, 0x803333ff, 0x803333ff
    ).setSymbolScale(dataZ1);

// Output the chart
String chart1URL = c.makeSession(request, "chart1");

// Include tool tip for the chart
String imageMap1 = c.getHTMLImageMap("", "",
    "title='[{dataSetName}] Range = {x} miles, Capacity = {value} tons, Length = {z} meters'");
%>
<html>
<body style="margin:5px 0px 0px 5px">
<div style="font-size:18pt; font-family:verdana; font-weight:bold">
    Bubble Chart
</div>
<hr color="#000080">
<div style="font-size:10pt; font-family:verdana; margin-bottom:1.5em">
    <a href="viewsource.jsp?file=<%=request.getServletPath()%>">View Source Code</a>
</div>
<img src='<%=response.encodeURL("getchart.jsp?"+chart1URL)%>'
    usemap="#map1" border="0">
<map name="map1"><%=imageMap1%></map>
</body>
</html>

[Java Version] javademo/bubble.java
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
import ChartDirector.*;

public class bubble implements DemoModule
{
    //Name of demo program
    public String toString() { return "Bubble Chart"; }

    //Number of charts produced in this demo
    public int getNoOfCharts() { return 1; }

    //Main code for creating charts
    public void createChart(ChartViewer viewer, int chartIndex)
    {
        // The XYZ points for the bubble chart
        double[] dataX0 = {150, 300, 1000, 1700};
        double[] dataY0 = {12, 60, 25, 65};
        double[] dataZ0 = {20, 50, 50, 85};

        double[] dataX1 = {500, 1000, 1300};
        double[] dataY1 = {35, 50, 75};
        double[] dataZ1 = {30, 55, 95};

        // Create a XYChart object of size 450 x 420 pixels
        XYChart c = new XYChart(450, 420);

        // Set the plotarea at (55, 65) and of size 350 x 300 pixels, with a light grey border
        // (0xc0c0c0). Turn on both horizontal and vertical grid lines with light grey color
        // (0xc0c0c0)
        c.setPlotArea(55, 65, 350, 300, -1, -1, 0xc0c0c0, 0xc0c0c0, -1);

        // Add a legend box at (50, 30) (top of the chart) with horizontal layout. Use 12pt Times
        // Bold Italic font. Set the background and border color to Transparent.
        c.addLegend(50, 30, false, "Times New Roman Bold Italic", 12).setBackground(
            Chart.Transparent);

        // Add a title to the chart using 18pt Times Bold Itatic font.
        c.addTitle("Product Comparison Chart", "Times New Roman Bold Italic", 18);

        // Add a title to the y axis using 12pt Arial Bold Italic font
        c.yAxis().setTitle("Capacity (tons)", "Arial Bold Italic", 12);

        // Add a title to the x axis using 12pt Arial Bold Italic font
        c.xAxis().setTitle("Range (miles)", "Arial Bold Italic", 12);

        // Set the axes line width to 3 pixels
        c.xAxis().setWidth(3);
        c.yAxis().setWidth(3);

        // Add (dataX0, dataY0) as a scatter layer with semi-transparent red (0x80ff3333) circle
        // symbols, where the circle size is modulated by dataZ0. This creates a bubble effect.
        c.addScatterLayer(dataX0, dataY0, "Technology AAA", Chart.CircleSymbol, 9, 0x80ff3333,
            0x80ff3333).setSymbolScale(dataZ0);

        // Add (dataX1, dataY1) as a scatter layer with semi-transparent green (0x803333ff) circle
        // symbols, where the circle size is modulated by dataZ1. This creates a bubble effect.
        c.addScatterLayer(dataX1, dataY1, "Technology BBB", Chart.CircleSymbol, 9, 0x803333ff,
            0x803333ff).setSymbolScale(dataZ1);

        // Output the chart
        viewer.setChart(c);

        //include tool tip for the chart
        viewer.setImageMap(c.getHTMLImageMap("clickable", "",
            "title='[{dataSetName}] Range = {x} miles, Capacity = {value} tons, Length = {z} " +
            "meters'"));
    }

    //Allow this module to run as standalone program for easy testing
    public static void main(String[] args)
    {
        //Instantiate an instance of this demo module
        DemoModule demo = new bubble();

        //Create and set up the main window
        JFrame frame = new JFrame(demo.toString());
        frame.addWindowListener(new WindowAdapter() {
            public void windowClosing(WindowEvent e) {System.exit(0);} });
        frame.getContentPane().setBackground(Color.white);

        // Create the chart and put them in the content pane
        ChartViewer viewer = new ChartViewer();
        demo.createChart(viewer, 0);
        frame.getContentPane().add(viewer);

        // Display the window
        frame.pack();
        frame.setVisible(true);
    }
}