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Copyright 2000-2002,2007 Anthony Cook. All rights reserved.
This program is free software, you can redistribute it and/or
modify it under the same terms as Perl itself.
What is it?
===========
Imager::Graph is intended to produce good looking graphs with a
minimum effort on the part of the user. Hopefully I've managed that.
Currently only the pie graph class, Imager::Graph::Pie, is provided.
Fonts
=====
For best results you will need one or more attractive fonts, and one
of the outline font libraries that Imager supports. The ImUgly font
is supplied with Imager::Graph, but it is fairly ugly, so probably
isn't useful if you want nice output.
Installation
============
Imager::Graph follows the normal perl module installation process:
perl Makefile.PL
make
make test
make install
Please Note: don't be too suprised if you get test failures,
unfortunately minor changes in the image can result in large changes
in the measure I use to check the results. If you get test failures
please check the results in testout/
The tests require PNG file format and TrueType font format support.
Creating Graphs
===============
The aim is to make things as simple as possible, if you have some data
you can create a pie chart with:
use Imager::Graph::Pie;
my $font = Imager::Font->new(file=>$fontfile)
or die "Cannot create font: ",Imager->errstr;
my $pie_graph = Imager::Graph::Pie->new();
my $img = $pie_graph->draw(data=>\@data);
If you want to add a legend, you need to provide some descriptive text
as well:
my $img = $pie_graph->draw(data=>\@data, labels=>\@labels, font=>$font,
features=>'legend');
You might want to add a title instead:
my $img = $pie_graph->draw(data=>\@data, font=>$font, title=>'MyGraph');
or instead of a legend, use callouts to annotate each segment:
my $img = $pie_graph->draw(data=>\@data, labels=>\@labels,
features=>'allcallouts', font=>$font);
(The following graphs use features introduce after Imager 0.38.)
If you want draw a monochrome pie graph, using hatched fills, specify
the 'mono' style:
my $img = $pie_graph->draw(data=>\@data, style=>'mono');
The 'mono' style produces a 1 channel image by default, so if you want
to add some color you need to reset the number of channels, for
example, you could change the drawing color to red:
my $img = $pie_graph->draw(data=>\@data, style=>'mono',
fg=>'FF0000', channels=>3);
If you're feeling particularly adventurous, you could create a graph
with a transparent background, suitable for compositing onto another
image:
my $img = $pie_graph->draw(data=>\@data, style=>'mono',
bg=>'00000000', channels=>4);
If you only want the background of the graph to be transparent, while leaving other parts of the chart opaque, use the back option:
my $img = $pie_graph->draw(data=>\@data, style=>'mono',
back=>'00000000', channels=>4);
or you could make the background an image based fill:
my $img = $pie_graph->draw(data=>\@data, style=>'mono', channels=>4,
back=>{ image=>$otherimage } );
If you want a "prettier" image, you could use one of the fountain fill
based styles:
my $img = $pie_graph->draw(data=>\@data, style=>'fount_lin');
The image you receive from Imager::Graph is a normal Imager image,
typically an 8-bit/sample direct color image, though options to extend
that may be introduced in the future.
Portability
===========
Imager::Graph should work on any system that Imager works on.
More Information
================
If you have queries about Imager::Graph, please email me at
tony@develop-help.com.
A PPM compatible version of this module should be available from
http://ppd.develop-help.com/.
Thanks go to Addi for Imager.