#!/usr/local/bin/perl
#
# Pie Chart Baker!
# Rudy Rucker, (c) Nov, 2002
#
use CGI ':standard';
use GD::Graph::pie;
my $query = new CGI;
for (1..100) {
	defined $query->param('value'.$_) or last;
	$query->param('value'.$_) == 0 and next;
	my ($l, $v) = ($query->param('label'.$_), $query->param('value'.$_));
	$v =~ /^[0-9\.]{1,9}$/ or next;     #valid numbers, please
	$l =~ tr/a-zA-Z0-9 \-=+\.\?\!/_/cd; #pick a few valid characters.
	$l =~ s/^(.{16}).*$/$1/;            #limit the length of a label
	push @{$data[0]}, $l;
	push @{$data[1]}, $v;
}
$query->param('Td') eq 'on' ? ($threeD = 1) : ($threeD =  0);
unless (@data) {
	$threeD = 1;
	$query->param('title', 'Rudy Drinks...');
 	@data = ( ["coffee","beer","milk","water","soda"], [90,70,40,110,40]);
}
my $graph = GD::Graph::pie->new(300, 300);
$graph->set( dclrs => [ qw(red green white lblue lyellow) ] );
$graph->set( title => $query->param('title'), '3d' => $threeD, 'accentclr' => "yellow") or warn $graph->error;
$graph->set_value_font(GD::gdMediumBoldFont);
my $imageObject = $graph->plot(\@data) or die $graph->error;
my $blob = $imageObject->png;
print "Content-type: image/png\n";
print "Content-length: ",length($blob),"\n\n";
print $blob;

__END__

This is a short example of pie chart (via CGI) generation.
	pie slice colors 
	       $graph->set( dclrs => [ qw(red green white lblue cyan) ] );
	3d  If set to a true value, the pie chart will be drawn
           with a 3d look.  Default: 1.
    pie_height
           The thickness of the pie when 3d is true.  Default:
           0.1 x height.
    start_angle
           The angle at which the first data slice will be
           displayed, with 0 degrees being "6 o'clock".  Default:
           0.
    suppress_angle
           If a pie slice is smaller than this angle (in
           degrees), a label will not be drawn on it. Default: 0.
    label
           Print this label below the pie. Default: undef.


in under 10 lines (note cheating with multiple commands per line!)
#!/bin/perl
use CGI ':standard'; use GD::Graph::pie; my $query = new CGI;
for (1..100) {
    $query->param('value'.$_) or last;
    my ($l, $v) = ($query->param('label'.$_), $query->param('value'.$_));
    push @{$data[0]}, $l; push @{$data[1]}, $v;
}
my $graph = GD::Graph::pie->new(300, 300);
my $imageObject = $graph->plot(\@data) or die $graph->error;
print "Content-type: image/png\n\n", $imageObject->png;