Dual Y-Axis

This example demonstrates a chart with two independent y-axis.

ChartDirector supports arbitrary number of axes. The first two x and y axes are most commonly used and can be retrieved using XYChart.xAxis, XYChart.xAxis2, XYChart.yAxis and XYChart.yAxis2. These axes are by default put at the edges of the plot area.

By default, a data set will bind to the primary y-axis. This can be modified by using DataSet.setUseYAxis or DataSet.setUseYAxis2.

The y-axes in this example are of different colors. This is achieved by using Axis.setColors.

[JSP Version] jspdemo/dualyaxis.jsp

<%@page import="ChartDirector.*, java.util.*" %>
<%
// The data for the chart
double[] data0 = {0.05, 0.06, 0.48, 0.1, 0.01, 0.05};
double[] data1 = {100, 125, 265, 147, 67, 105};
String[] labels = {"Jan", "Feb", "Mar", "Apr", "May", "Jun"};

// Create a XYChart object of size 300 x 180 pixels
XYChart c = new XYChart(300, 180);

// Set the plot area at (50, 20) and of size 200 x 130 pixels
c.setPlotArea(50, 20, 200, 130);

// Add a title to the chart using 8pt Arial Bold font
c.addTitle("Independent Y-Axis Demo", "Arial Bold", 8);

// Set the labels on the x axis.
c.xAxis().setLabels(labels);

// Add a title to the primary (left) y axis
c.yAxis().setTitle("Packet Drop Rate (pps)");

// Set the axis, label and title colors for the primary y axis to red (0xc00000) to match the first
// data set
c.yAxis().setColors(0xc00000, 0xc00000, 0xc00000);

// Add a title to the secondary (right) y axis
c.yAxis2().setTitle("Throughtput (MBytes)");

// set the axis, label and title colors for the primary y axis to green (0x008000) to match the
// second data set
c.yAxis2().setColors(0x008000, 0x008000, 0x008000);

// Add a line layer to for the first data set using red (0xc00000) color with a line width to 3
// pixels
LineLayer lineLayer = c.addLineLayer(data0, 0xc00000);
lineLayer.setLineWidth(3);

// tool tip for the line layer
lineLayer.setHTMLImageMap("", "", "title='Packet Drop Rate on {xLabel}: {value} pps'");

// Add a bar layer to for the second data set using green (0x00C000) color. Bind the second data set
// to the secondary (right) y axis
BarLayer barLayer = c.addBarLayer(data1, 0x00c000);
barLayer.setUseYAxis2();

// tool tip for the bar layer
barLayer.setHTMLImageMap("", "", "title='Throughput on {xLabel}: {value} MBytes'");

// Output the chart
WebChartViewer viewer = new WebChartViewer(request, "chart1");
viewer.setChart(c, Chart.SVG);

// include tool tip for the chart
viewer.setImageMap(c.getHTMLImageMap(""));
%>
<!DOCTYPE html>
<html>
<head>
    <title>Dual Y-Axis</title>
    <!-- Include ChartDirector Javascript Library to support chart interactions -->
    <script type="text/javascript" src="cdjcv.js"></script>
</head>
<body style="margin:5px 0px 0px 5px">
    <div style="font:bold 18pt verdana;">
        Dual Y-Axis
    </div>
    <hr style="border:solid 1px #000080; background:#000080" />
    <div style="font:10pt verdana; margin-bottom:1.5em">
        <a href="viewsource.jsp?file=<%=request.getServletPath()%>">View Source Code</a>
    </div>
    <!-- ****** Here is the chart image ****** -->
    <%= viewer.renderHTML(response) %>
</body>
</html>