This example illustrates
side label layout for pie charts, in which the sector labels are positioned on the left and right sides of the chart. The alternative is
circular label layout, in which the sector labels are positioned circularly around the pie.
Circular label layout usually uses less space and is the default layout method. However, if the pie chart contains a lot of small sectors, the labels may overlap with each others. It is because there may be insufficient space on the pie perimeter to position the labels.
Side label layout has the advantages that the labels will move up and down automatically to avoid overlapping.
The label layout method to use is determined by using
PieChart.setLabelLayout.
[File: perldemo/sidelabelpie.pl] (The CGI version is available as "perldemo_cgi/sidelabelpie.pl".)
#!/usr/bin/perl
use perlchartdir;
#The data for the pie chart
my $data = [25, 18, 15, 12, 8, 30, 35];
#The labels for the pie chart
my $labels = ["Labor", "Licenses", "Taxes", "Legal", "Insurance", "Facilities",
"Production"];
#Create a PieChart object of size 500 x 230 pixels
my $c = new PieChart(500, 230);
#Set the center of the pie at (250, 120) and the radius to 100 pixels
$c->setPieSize(250, 120, 100);
#Add a title box using 14 points Times Bold Italic as font
$c->addTitle("Project Cost Breakdown", "timesbi.ttf", 14);
#Draw the pie in 3D
$c->set3D();
#Use the side label layout method
$c->setLabelLayout($perlchartdir::SideLayout);
#Set the pie data and the pie labels
$c->setData($data, $labels);
#output the chart
$c->makeChart("sidelabelpie.png")
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