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.