NAME
GraphViz - Interface to the GraphViz graphing tool
SYNOPSIS
use GraphViz;
my $g = GraphViz->new();
$g->add_node({ name => 'London'});
$g->add_node({ name => 'Paris', label => 'City of\nlurve'});
$g->add_node({ name => 'New York'});
$g->add_edge({ from => 'London',
to => 'Paris',});
$g->add_edge({ from => 'London',
to => 'New York',
label => 'Far'});
$g->add_edge({ from => 'Paris',
to => 'London',});
print $g->as_png;DESCRIPTION
This modules provides an interface to layout and generate images of directed graphs in a variety of formats (PostScript, PNG, etc.) using the "dotneato" program from the GraphViz project (http://www.graphviz.org/).
At the moment this is a fairly simple library. Some features of dotneato are not currently implemented, such as graph attributes. Feature requests are welcome!
METHODS
new
This is the constructor. It currently takes no arguments:
my $g = GraphViz->new();add_node
A graph consists of at least one node. This method creates a new node and assigns it attributes. Various attributes are possible: "name" suggests a name for the node (if you do not supply one, one is generated for you and returned), "label" provides a label for the node (the label defaults to the name if none is specified). See the "dot" manpage under "NODE ATTRIBUTES" for others.
$g->add_node({ name => 'Paris', label => 'City of\nlurve'});
$g->add_node({ name => 'Paris', label => ['A', 'B', 'C']});Nodes can be clustered together with the "cluster" attribute, which is drawn by having a labelled rectangle around all the nodes in a cluster.
$g->add_node({ name => 'London', cluster => 'Europe'});
$g->add_node({ name => 'Amsterdam', cluster => 'Europe'});Also, nodes can consist of multiple parts (known as ports). This is implemented by passing an array reference as the label, and the parts are displayed as a label. GraphViz has a much more complete port system, this is just a simple interface to it.
$g->add_node({ name => 'London', label => ['Heathrow', 'Gatwick']});add_edge
Edges are directed links between nodes. This method creates a new edge between two nodes and optionally assigns it attributes. Two mandatory parameters are 'from' and 'to', which indicate the node names that the edge connects. Optional attributes such as 'label' are also available (see the "dot" manpage under the "EDGE ATTRIBUTES" for others).
$g->add_edge({ from => 'London',
to => 'New York',
label => 'Far'});Adding edges between ports of a node is done via the 'from_port' and 'to_port' parameters, which currently takes in the offset of the port (ie 0, 1, 2...).
$g->add_edge({ from => 'London',
from_port => 0,
to => 'Paris',
});as_canon, as_text, as_gif etc. methods
There are a number of methods which generate input for dotneato or output the graph in a variety of formats.
- as_canon
-
The as_canon method returns the canonical dotneato file which corresponds to the graph. It does not layout the graph - every other as_* method does.
print $g->as_canon; # prints out something like: digraph test { node [ label = "\N" ]; London [label=London]; Paris [label="City of\nlurve"]; New_York [label="New York"]; London -> Paris; London -> New_York [label=Far]; Paris -> London; } - as_text
-
The as_text method returns text which is a layed-out dotneato-format file.
print $g->as_text; # prints out something like: digraph test { node [ label = "\N" ]; graph [bb= "0,0,162,134"]; London [label=London, pos="33,116", width="0.89", height="0.50"]; Paris [label="City of\nlurve", pos="33,23", width="0.92", height="0.62"]; New_York [label="New York", pos="123,23", width="1.08", height="0.50"]; London -> Paris [pos="e,27,45 28,98 26,86 26,70 27,55"]; London -> New_York [label=Far, pos="e,107,40 49,100 63,85 84,63 101,46", lp="99,72"]; Paris -> London [pos="s,38,98 39,92 40,78 40,60 39,45"]; } - as_ps
-
Returns a string which contains a layed-out PostScript-format file.
print $g->as_ps; - as_hpgl
-
Returns a string which contains a layed-out HP pen plotter-format file.
print $g->as_hpgl; - as_pcl
-
Returns a string which contains a layed-out Laserjet printer-format file.
print $g->as_pcl; - as_mif
-
Returns a string which contains a layed-out FrameMaker graphics-format file.
print $g->as_mif; - as_pic
-
Returns a string which contains a layed-out PIC-format file.
print $g->as_pic; - as_gd
-
Returns a string which contains a layed-out GD-format file.
print $g->as_gd; - as_gd2
-
Returns a string which contains a layed-out GD2-format file.
print $g->as_gd2; - as_gif
-
Returns a string which contains a layed-out GIF-format file.
print $g->as_gif; - as_jpeg
-
Returns a string which contains a layed-out JPEG-format file.
print $g->as_jpeg; - as_png
-
Returns a string which contains a layed-out PNG-format file.
print $g->as_png; - as_wbmp
-
Returns a string which contains a layed-out Windows BMP-format file.
print $g->as_wbmp; - as_ismap
-
Returns a string which contains a layed-out HTML client-side image map format file.
print $g->as_ismap; - as_imap
-
Returns a string which contains a layed-out HTML server-side image map format file.
print $g->as_imap; - as_vrml
-
Returns a string which contains a layed-out VRML-format file.
print $g->as_vrml; - as_vtx
-
Returns a string which contains a layed-out VTX (Visual Thought) format file.
print $g->as_vtx; - as_mp
-
Returns a string which contains a layed-out MetaPost-format file.
print $g->as_mp; - as_fig
-
Returns a string which contains a layed-out FIG-format file.
print $g->as_fig; - as_svg
-
Returns a string which contains a layed-out SVG-format file.
print $g->as_svg; - as_plain
-
Returns a string which contains a layed-out simple-format file.
print $g->as_plain;
AUTHOR
Leon Brocard <acme@astray.com>
COPYRIGHT
Copyright (C) 2000, Leon Brocard
This module is free software; you can redistribute it or modify it under the same terms as Perl itself.