NAME
Graph::XGMML - Simple Graph.pm-like interface for generating XGMML
graphs
SYNOPSIS
use Graph::XGMML;
my $output = '';
my $graph = Graph::XGMML->new(
directed => 1,
OUTPUT => \$output,
);
$graph->add_node('foo');
$graph->add_node('bar');
$graph->add_edge('foo', 'bar');
$graph->end;
DESCRIPTION
To produce useful diagrams on extremely large graphs, sometimes it is
necesary to move beyond simple graphing tools to applications
specifically designed for rendering very large graphs, many of which
were designed for biology applications (such as my favourite Cytoscape).
Graph::XGMML is a module that can be used to generate export files for
arbitrarily large graphs in eXtensible Graph Modelling Markup Language,
so that the graphs can be imported into these specialised tools.
The API is intentionally designed to appear similar to more popular
modules such as Graph, Graph::Easy and GraphViz.
METHODS
new
# Quick constructor to write to a file
$graph = Graph::XGMML->new(
directed => 1,
OUTPUT => IO::File->new('file', 'w'),
);
# Anonymous constructor
$graph = Graph::XGMML->new(
directed => 1,
);
The "new" constructor is used to create a graph writer.
It takes a single optional boolean "directed" parameter, which indicates
if the graphs you will be generating will be directed or undirected.
If any additional parameters are passed to "new", the constructor will
make an additional call to the "start" method to start writing the
document header and to open the root "graph" node, passing it the extra
parameters.
Returns a new Graph::XGMML object, or throws an exception (dies) on
error.
start
The "start" method allows you to explicitly start the document writing,
if the original constructor was produced without additional parameters.
Any parameters are passed directly to the underlying XML::Writer
constructor which produces the object that will be used to generate the
XML.
Returns true if the document is started successfully, or throws an
exception (dies) on error.
add_node
# Add a simple node
$graph->add_node( 'name' );
# Add optional tag attributes
$graph->add_node( 'name',
label => 'Tag Label',
weight => 100,
);
The "add_node" method is used to add a new node to the graph.
Because the Graph::XGMML object doesn't remember its state as it
produces the graph, you must specify all nodes in the graph explicitly.
The first parameter is the identifier for the node. Any additional
parameters will be treated XGMML "node" element tag pairs.
Returns true or throws an exception (dies) on error.
add_vertex
The "add_vertex" method is an alias to "add_node", provided for
increased compatibility with the Graph API.
It takes the same parameters as "add_node".
add_edge
# Add a simple edge
$graph->add_edge( 'foo' => 'bar' );
# Add with optional attributes
$graph->add_edge( 'foo' => 'bar',
weight => 1,
);
The c<add_edge> method adds an edge to the graph.
The first two parameters are the source and target of the edge. Any
additional parameters should be a set of key/value pairs of edge
attributes.
Returns true or throws an exception (dies) on error.
end
# Explicitly terminate the document
$graph->end;
The "end" method is used to indicate that the graph is completed that
the XML should be terminated.
If you do not call it yourself, it will be called for you at
"DESTROY"-time.
SUPPORT
Bugs should always be submitted via the CPAN bug tracker
<
http://rt.cpan.org/NoAuth/ReportBug.html?Queue=Graph-XGMML>
For other issues, contact the maintainer.
AUTHOR
Adam Kennedy <
[email protected]>
SEE ALSO
Graph, Graph::Easy, GraphViz
COPYRIGHT
Copyright 2009 Adam Kennedy.
This program is free software; you can redistribute it and/or modify it
under the same terms as Perl itself.
The full text of the license can be found in the LICENSE file included
with this module.
