ChartDirector Ver 3.0 (Perl Edition)

Dual Y-Axis




This example show demonstrates the dual independent y-axis feature of ChartDirector.

In ChartDirector, any data set can be binded to the primary y-axis or the secondary y-axis, controlled by DataSet.setUseYAxis2. The default is the primary y-axis.

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

Source Code Listing

[File: perldemo/dualyaxis.pl] (The CGI version is available as "perldemo_cgi/dualyaxis.pl".)
#!/usr/bin/perl use perlchartdir; #The data for the chart my $data0 = [0.05, 0.06, 0.48, 0.1, 0.01, 0.05]; my $data1 = [100, 125, 265, 147, 67, 105]; my $labels = ["Jan", "Feb", "Mar", "Apr", "May", "Jun"]; #Create a XYChart object of size 300 x 180 pixels my $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 8 pts Arial Bold font $c->addTitle("Independent Y-Axis Demo", "arialbd.ttf", 8); #Set the x axis labels using the given labels $c->xAxis()->setLabels($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(0x8000, 0x8000, 0x8000); #Add a line layer to for the first data set using red (0xc00000) color with a #line width to 3 pixels $c->addLineLayer($data0, 0xc00000)->setLineWidth(3); #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 $c->addBarLayer()->addDataSet($data1, 0xc000)->setUseYAxis2(); #output the chart $c->makeChart("dualyaxis.png")