ChartDirector 6.1 (Java Edition)

Contour Color Scale


      

This example demonstrates using various coloring for the ContourLayer.

The ChartDirector supports two ways to configure the colors for a contour.

This example includes 4 charts to demonstrate both of the above methods.

Source Code Listing

[JSP Version] jspdemo/contourcolor.jsp
<%@page import="ChartDirector.*" %>
<%@page import="javax.servlet.http.*" %>
<%!
// A simple structure to represent a chart image with an image map
private static class ImageWithHotSpot
{
    String imageURL;
    String imageMap;
}

// Function to create the demo charts
ImageWithHotSpot createChart(HttpServletRequest request, int chartIndex)
{
    // The x and y coordinates of the grid
    double[] dataX = {-4, -3, -2, -1, 0, 1, 2, 3, 4};
    double[] dataY = {-4, -3, -2, -1, 0, 1, 2, 3, 4};

    // Use random numbers for the z values on the XY grid
    RanSeries r = new RanSeries(99);
    double[] dataZ = r.get2DSeries(dataX.length, dataY.length, -0.9, 0.9);

    // Create a XYChart object of size 420 x 360 pixels
    XYChart c = new XYChart(420, 360);

    // Set the plotarea at (30, 25) and of size 300 x 300 pixels. Use semi-transparent grey
    // (0xdd000000) horizontal and vertical grid lines
    c.setPlotArea(30, 25, 300, 300, -1, -1, -1, 0xdd000000, -1);

    // Set the x-axis and y-axis scale
    c.xAxis().setLinearScale(-4, 4, 1);
    c.yAxis().setLinearScale(-4, 4, 1);

    // Add a contour layer using the given data
    ContourLayer layer = c.addContourLayer(dataX, dataY, dataZ);

    // Move the grid lines in front of the contour layer
    c.getPlotArea().moveGridBefore(layer);

    // Add a color axis (the legend) in which the top left corner is anchored at (350, 25). Set the
    // length to 400 300 and the labels on the right side.
    ColorAxis cAxis = layer.setColorAxis(350, 25, Chart.TopLeft, 300, Chart.Right);

    if (chartIndex == 1) {
        // Speicify a color gradient as a list of colors, and use it in the color axis.
        int[] colorGradient = {0x0044cc, 0xffffff, 0x00aa00};
        cAxis.setColorGradient(false, colorGradient);
    } else if (chartIndex == 2) {
        // Specify the color scale to use in the color axis
        double[] colorScale = {-1.0, 0x1a9850, -0.75, 0x66bd63, -0.5, 0xa6d96a, -0.25, 0xd9ef8b, 0,
            0xfee08b, 0.25, 0xfdae61, 0.5, 0xf46d43, 0.75, 0xd73027, 1};
        cAxis.setColorScale(colorScale);
    } else if (chartIndex == 3) {
        // Specify the color scale to use in the color axis. Also specify an underflow color
        // 0x66ccff (blue) for regions that fall below the lower axis limit.
        double[] colorScale = {0, 0xffff99, 0.2, 0x80cdc1, 0.4, 0x35978f, 0.6, 0x01665e, 0.8,
            0x003c30, 1};
        cAxis.setColorScale(colorScale, 0x66ccff);
    }

    // Output the chart
    ImageWithHotSpot ret = new ImageWithHotSpot();
    ret.imageURL = c.makeSession(request, "chart" + chartIndex);
    return ret;
}
%>
<%
ImageWithHotSpot chart0 = createChart(request, 0);
ImageWithHotSpot chart1 = createChart(request, 1);
ImageWithHotSpot chart2 = createChart(request, 2);
ImageWithHotSpot chart3 = createChart(request, 3);
%>
<html>
<body style="margin:5px 0px 0px 5px">
<div style="font-size:18pt; font-family:verdana; font-weight:bold">
    Contour Color Scale
</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?"+chart0.imageURL)%>'>
<img src='<%=response.encodeURL("getchart.jsp?"+chart1.imageURL)%>'>
<img src='<%=response.encodeURL("getchart.jsp?"+chart2.imageURL)%>'>
<img src='<%=response.encodeURL("getchart.jsp?"+chart3.imageURL)%>'>
</body>
</html>

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

public class contourcolor implements DemoModule
{
    //Name of demo program
    public String toString() { return "Contour Color Scale"; }

    //Number of charts produced in this demo
    public int getNoOfCharts() { return 4; }

    //Main code for creating charts
    public void createChart(ChartViewer viewer, int chartIndex)
    {
        // The x and y coordinates of the grid
        double[] dataX = {-4, -3, -2, -1, 0, 1, 2, 3, 4};
        double[] dataY = {-4, -3, -2, -1, 0, 1, 2, 3, 4};

        // Use random numbers for the z values on the XY grid
        RanSeries r = new RanSeries(99);
        double[] dataZ = r.get2DSeries(dataX.length, dataY.length, -0.9, 0.9);

        // Create a XYChart object of size 420 x 360 pixels
        XYChart c = new XYChart(420, 360);

        // Set the plotarea at (30, 25) and of size 300 x 300 pixels. Use semi-transparent grey
        // (0xdd000000) horizontal and vertical grid lines
        c.setPlotArea(30, 25, 300, 300, -1, -1, -1, 0xdd000000, -1);

        // Set the x-axis and y-axis scale
        c.xAxis().setLinearScale(-4, 4, 1);
        c.yAxis().setLinearScale(-4, 4, 1);

        // Add a contour layer using the given data
        ContourLayer layer = c.addContourLayer(dataX, dataY, dataZ);

        // Move the grid lines in front of the contour layer
        c.getPlotArea().moveGridBefore(layer);

        // Add a color axis (the legend) in which the top left corner is anchored at (350, 25). Set
        // the length to 400 300 and the labels on the right side.
        ColorAxis cAxis = layer.setColorAxis(350, 25, Chart.TopLeft, 300, Chart.Right);

        if (chartIndex == 1) {
            // Speicify a color gradient as a list of colors, and use it in the color axis.
            int[] colorGradient = {0x0044cc, 0xffffff, 0x00aa00};
            cAxis.setColorGradient(false, colorGradient);
        } else if (chartIndex == 2) {
            // Specify the color scale to use in the color axis
            double[] colorScale = {-1.0, 0x1a9850, -0.75, 0x66bd63, -0.5, 0xa6d96a, -0.25, 0xd9ef8b,
                0, 0xfee08b, 0.25, 0xfdae61, 0.5, 0xf46d43, 0.75, 0xd73027, 1};
            cAxis.setColorScale(colorScale);
        } else if (chartIndex == 3) {
            // Specify the color scale to use in the color axis. Also specify an underflow color
            // 0x66ccff (blue) for regions that fall below the lower axis limit.
            double[] colorScale = {0, 0xffff99, 0.2, 0x80cdc1, 0.4, 0x35978f, 0.6, 0x01665e, 0.8,
                0x003c30, 1};
            cAxis.setColorScale(colorScale, 0x66ccff);
        }

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

    //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 contourcolor();

        //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);
        frame.getContentPane().setLayout(new FlowLayout(FlowLayout.LEFT));
        frame.setSize(800, 450);

        // Create the charts and put them in the content pane
        for (int i = 0; i < demo.getNoOfCharts(); ++i)
        {
            ChartViewer viewer = new ChartViewer();
            demo.createChart(viewer, i);
            frame.getContentPane().add(viewer);
        }

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