ChartDirector Ver 4.1 (Perl Edition)

Start Angle and Direction


  

This example demonstrates different sector layout angles and directions.

By default, ChartDirector positions sectors starting from the upward pointing position, and in clockwise direction.

The start angle and layout direction can be changed using PieChart.setStartAngle.

One common application for the PieChart.setStartAngle method is to facilitate layout of pie charts containing many small sectors. Please refer to Pie with Small Sectors.

Source Code Listing

[Standalone Version] perldemo\anglepie.pl
#!/usr/bin/perl
use perlchartdir;

sub createChart
{
    my $img = shift;

    # query string to determine the starting angle and direction
    my $angle = 0;
    my $clockwise = 1;
    if ($img ne "0") {
        $angle = 90;
        $clockwise = 0;
    }

    # 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 280 x 240 pixels
    my $c = new PieChart(280, 240);

    # Set the center of the pie at (140, 130) and the radius to 80 pixels
    $c->setPieSize(140, 130, 80);

    # Add a title to the pie to show the start angle and direction
    if ($clockwise) {
        $c->addTitle("Start Angle = $angle degrees\nDirection = Clockwise");
    } else {
        $c->addTitle("Start Angle = $angle degrees\nDirection = AntiClockwise");
    }

    # Set the pie start angle and direction
    $c->setStartAngle($angle, $clockwise);

    # Draw the pie in 3D
    $c->set3D();

    # Set the pie data and the pie labels
    $c->setData($data, $labels);

    # Explode the 1st sector (index = 0)
    $c->setExplode(0);

    # output the chart
    $c->makeChart("anglepie$img.png")
}

createChart(0);
createChart(1);

[CGI Version] perldemo_cgi\anglepie.pl
#!/usr/bin/perl

# Include current script directory in the module path (needed on Microsoft IIS).
# This allows this script to work by copying ChartDirector to the same directory
# as the script (as an alternative to installation in Perl module directory)
use File::Basename;
use lib dirname($0);

use perlchartdir;

# Get HTTP query parameters
use CGI;
my $query = new CGI;

# query string to determine the starting angle and direction
my $angle = 0;
my $clockwise = 1;
if ($query->param("img") ne "0") {
    $angle = 90;
    $clockwise = 0;
}

# 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 280 x 240 pixels
my $c = new PieChart(280, 240);

# Set the center of the pie at (140, 130) and the radius to 80 pixels
$c->setPieSize(140, 130, 80);

# Add a title to the pie to show the start angle and direction
if ($clockwise) {
    $c->addTitle("Start Angle = $angle degrees\nDirection = Clockwise");
} else {
    $c->addTitle("Start Angle = $angle degrees\nDirection = AntiClockwise");
}

# Set the pie start angle and direction
$c->setStartAngle($angle, $clockwise);

# Draw the pie in 3D
$c->set3D();

# Set the pie data and the pie labels
$c->setData($data, $labels);

# Explode the 1st sector (index = 0)
$c->setExplode(0);

# output the chart
binmode(STDOUT);
print "Content-type: image/png\n\n";
print $c->makeChart2($perlchartdir::PNG);