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.

perldemo\dualyaxis.pl

#!/usr/bin/perl

# The ChartDirector for Perl module is assumed to be in "../lib"
use File::Basename;
use lib (dirname($0)."/../lib") =~ /(.*)/;

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 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
$c->addLineLayer($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
$c->addBarLayer($data1, 0x00c000)->setUseYAxis2();

# Output the chart
$c->makeChart("dualyaxis.png");