ChartDirector 6.1 (Java Edition)

Polar Scatter Chart




This example demonstrates how to create polar scatter charts. It also demonstrates using alternating background colors along the angular direction.

A polar scatter chart can be created as a polar line chart with data symbols. The line width is set to 0, so only the symbols can be seen. This will create the effects of a scatter chart.

The detail steps are:

Note that in this example, the polar plot area uses two alternating background colors along the angular direction. This is by using PolarChart.setPlotAreaBg.

Source Code Listing

[JSP Version] jspdemo/polarscatter.jsp
<%@page import="ChartDirector.*" %>
<%
// The data for the chart
double[] data0 = {43, 89, 76, 64, 48, 18, 92, 68, 44, 79, 71, 85};
double[] angles0 = {45, 96, 169, 258, 15, 30, 330, 260, 60, 75, 110, 140};

double[] data1 = {50, 91, 26, 29, 80, 53, 62, 87, 19, 40};
double[] angles1 = {230, 210, 240, 310, 179, 250, 244, 199, 89, 160};

double[] data2 = {88, 65, 76, 49, 80, 53};
double[] angles2 = {340, 310, 340, 210, 30, 300};

// The labels on the angular axis (spokes)
String[] labels = {"North", "North\nEast", "East", "South\nEast", "South", "South\nWest", "West",
    "North\nWest"};

// Create a PolarChart object of size 460 x 460 pixels
PolarChart c = new PolarChart(460, 460);

// Add a title to the chart at the top left corner using 15pt Arial Bold Italic font
c.addTitle2(Chart.TopLeft, "<*underline=2*>Plants in Wonderland", "Arial Bold Italic", 15);

// Set center of plot area at (230, 240) with radius 180 pixels
c.setPlotArea(230, 240, 180);

// Use alternative light grey/dark grey sector background color
c.setPlotAreaBg(0xdddddd, 0xeeeeee, false);

// Set the grid style to circular grid
c.setGridStyle(false);

// Add a legend box at the top right corner of the chart using 9pt Arial Bold font
c.addLegend(459, 0, true, "Arial Bold", 9).setAlignment(Chart.TopRight);

// Set angular axis as 0 - 360, either 8 spokes
c.angularAxis().setLinearScale2(0, 360, labels);

// Set the radial axis label format
c.radialAxis().setLabelFormat("{value} km");

// Add a blue (0xff) polar line layer to the chart using (data0, angle0)
PolarLineLayer layer0 = c.addLineLayer(data0, 0x0000ff, "Immortal Weed");
layer0.setAngles(angles0);

layer0.setLineWidth(0);
layer0.setDataSymbol(Chart.TriangleSymbol, 11);

// Add a red (0xff0000) polar line layer to the chart using (data1, angles1)
PolarLineLayer layer1 = c.addLineLayer(data1, 0xff0000, "Precious Flower");
layer1.setAngles(angles1);

// Disable the line by setting its width to 0, so only the symbols are visible
layer1.setLineWidth(0);

// Use a 11 pixel diamond data point symbol
layer1.setDataSymbol(Chart.DiamondSymbol, 11);

// Add a green (0x00ff00) polar line layer to the chart using (data2, angles2)
PolarLineLayer layer2 = c.addLineLayer(data2, 0x00ff00, "Magical Tree");
layer2.setAngles(angles2);

// Disable the line by setting its width to 0, so only the symbols are visible
layer2.setLineWidth(0);

// Use a 9 pixel square data point symbol
layer2.setDataSymbol(Chart.SquareSymbol, 9);

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

// Include tool tip for the chart
String imageMap1 = c.getHTMLImageMap("", "", "title='{dataSetName} at ({value} km, {angle} deg)'");
%>
<html>
<body style="margin:5px 0px 0px 5px">
<div style="font-size:18pt; font-family:verdana; font-weight:bold">
    Polar Scatter 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/polarscatter.java
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
import ChartDirector.*;

public class polarscatter implements DemoModule
{
    //Name of demo program
    public String toString() { return "Polar Scatter 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 data for the chart
        double[] data0 = {43, 89, 76, 64, 48, 18, 92, 68, 44, 79, 71, 85};
        double[] angles0 = {45, 96, 169, 258, 15, 30, 330, 260, 60, 75, 110, 140};

        double[] data1 = {50, 91, 26, 29, 80, 53, 62, 87, 19, 40};
        double[] angles1 = {230, 210, 240, 310, 179, 250, 244, 199, 89, 160};

        double[] data2 = {88, 65, 76, 49, 80, 53};
        double[] angles2 = {340, 310, 340, 210, 30, 300};

        // The labels on the angular axis (spokes)
        String[] labels = {"North", "North\nEast", "East", "South\nEast", "South", "South\nWest",
            "West", "North\nWest"};

        // Create a PolarChart object of size 460 x 460 pixels
        PolarChart c = new PolarChart(460, 460);

        // Add a title to the chart at the top left corner using 15pt Arial Bold Italic font
        c.addTitle2(Chart.TopLeft, "<*underline=2*>Plants in Wonderland", "Arial Bold Italic", 15);

        // Set center of plot area at (230, 240) with radius 180 pixels
        c.setPlotArea(230, 240, 180);

        // Use alternative light grey/dark grey sector background color
        c.setPlotAreaBg(0xdddddd, 0xeeeeee, false);

        // Set the grid style to circular grid
        c.setGridStyle(false);

        // Add a legend box at the top right corner of the chart using 9pt Arial Bold font
        c.addLegend(459, 0, true, "Arial Bold", 9).setAlignment(Chart.TopRight);

        // Set angular axis as 0 - 360, either 8 spokes
        c.angularAxis().setLinearScale2(0, 360, labels);

        // Set the radial axis label format
        c.radialAxis().setLabelFormat("{value} km");

        // Add a blue (0xff) polar line layer to the chart using (data0, angle0)
        PolarLineLayer layer0 = c.addLineLayer(data0, 0x0000ff, "Immortal Weed");
        layer0.setAngles(angles0);

        layer0.setLineWidth(0);
        layer0.setDataSymbol(Chart.TriangleSymbol, 11);

        // Add a red (0xff0000) polar line layer to the chart using (data1, angles1)
        PolarLineLayer layer1 = c.addLineLayer(data1, 0xff0000, "Precious Flower");
        layer1.setAngles(angles1);

        // Disable the line by setting its width to 0, so only the symbols are visible
        layer1.setLineWidth(0);

        // Use a 11 pixel diamond data point symbol
        layer1.setDataSymbol(Chart.DiamondSymbol, 11);

        // Add a green (0x00ff00) polar line layer to the chart using (data2, angles2)
        PolarLineLayer layer2 = c.addLineLayer(data2, 0x00ff00, "Magical Tree");
        layer2.setAngles(angles2);

        // Disable the line by setting its width to 0, so only the symbols are visible
        layer2.setLineWidth(0);

        // Use a 9 pixel square data point symbol
        layer2.setDataSymbol(Chart.SquareSymbol, 9);

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

        //include tool tip for the chart
        viewer.setImageMap(c.getHTMLImageMap("clickable", "",
            "title='{dataSetName} at ({value} km, {angle} deg)'"));
    }

    //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 polarscatter();

        //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);
    }
}