This is just a fork to get a fixed version of this gem. I would prefer the original author to do this, but he seems to have abandoned this gem and I need this fix.

This is the original README with original author etc. All respect is to him.

= Ruby/GraphViz

{<img src="https://secure.travis-ci.org/glejeune/Ruby-Graphviz.png" />}[http://travis-ci.org/glejeune/Ruby-Graphviz]
{<img src="https://badge.fury.io/rb/ruby-graphviz.png" alt="Gem Version" />}[http://badge.fury.io/rb/ruby-graphviz]

Copyright (C) 2004-2013 Gregoire Lejeune

* Doc : http://rdoc.info/projects/glejeune/Ruby-Graphviz
* Sources : http://github.com/glejeune/Ruby-Graphviz
* <b>NEW</b> - Mailing List : http://groups.google.com/group/ruby-graphviz

== DESCRIPTION

Interface to the GraphViz graphing tool

== TODO

* New FamilyTree

== SYNOPSIS

A basic example

  require 'graphviz'

  # Create a new graph
  g = GraphViz.new( :G, :type => :digraph )

  # Create two nodes
  hello = g.add_nodes( "Hello" )
  world = g.add_nodes( "World" )

  # Create an edge between the two nodes
  g.add_edges( hello, world )

  # Generate output image
  g.output( :png => "hello_world.png" )
  
The same but with a block

  require 'graphviz'

  GraphViz::new( :G, :type => :digraph ) { |g|
    g.world( :label => "World" ) << g.hello( :label => "Hello" )
  }.output( :png => "hello_world.png" )

Or with the DSL

  require 'graphviz/dsl'
  digraph :G do
    world[:label => "World"] << hello[:label => "Hello"]

    output :png => "hello_world.png"
  end

Create a graph from a file 

  require 'graphviz'

  # In this example, hello.dot is :
  #   digraph G {Hello->World;}

  GraphViz.parse( "hello.dot", :path => "/usr/local/bin" ) { |g|
    g.get_node("Hello") { |n|
      n[:label] = "Bonjour"
    }
    g.get_node("World") { |n|
      n[:label] = "Le Monde"
    }
  }.output(:png => "sample.png")

GraphML[http://graphml.graphdrawing.org/] support

  require 'graphviz/graphml'
  
  g = GraphViz::GraphML.new( "graphml/cluster.graphml" )
  g.graph.output( :path => "/usr/local/bin", :png => "#{$0}.png" )


== TOOLS

Ruby/GraphViz also includes :

* <tt>ruby2gv</tt>, a simple tool that allows you to create a dependency graph from a ruby script. Example : http://drp.ly/dShaZ

    ruby2gv -Tpng -oruby2gv.png ruby2gv

* <tt>gem2gv</tt>, a tool that allows you to create a dependency graph between gems. Example : http://drp.ly/dSj9Y

    gem2gv -Tpng -oruby-graphviz.png ruby-graphviz

* <tt>dot2ruby</tt>, a tool that allows you to create a ruby script from a graphviz script

    $ cat hello.dot
    digraph G {Hello->World;}
    
    $ dot2ruby hello.dot
    # This code was generated by dot2ruby.g
    
    require 'rubygems'
    require 'graphviz'
    graph_g = GraphViz.digraph( "G" ) { |graph_g|
      graph_g[:bb] = '0,0,70,108'
      node_hello = graph_g.add_nodes( "Hello", :height => '0.5', :label => '\N', :pos => '35,90', :width => '0.88889' )
      graph_g.add_edges( "Hello", "World", :pos => 'e,35,36.413 35,71.831 35,64.131 35,54.974 35,46.417' )
      node_world = graph_g.add_nodes( "World", :height => '0.5', :label => '\N', :pos => '35,18', :width => '0.97222' )
    }
    puts graph_g.output( :canon => String )

* <tt>git2gv</tt>, a tool that allows you to show your git commits : http://dl.dropbox.com/u/72629/ruby-graphviz-git.svg

* <tt>xml2gv</tt>, a tool that allows you to show a xml file as graph.

== GRAPH THEORY

  require 'graphviz'
  require 'graphviz/theory'
  
  g = GraphViz.new( :G ) { ... }
  
  t = GraphViz::Theory.new( g )
  
  puts "Adjancy matrix : "
  puts t.adjancy_matrix
  
  puts "Symmetric ? #{t.symmetric?}"
  
  puts "Incidence matrix :"
  puts t.incidence_matrix
  
  g.each_node do |name, node|
    puts "Degree of node `#{name}' = #{t.degree(node)}"
  end
  
  puts "Laplacian matrix :"
  puts t.laplacian_matrix
  
  puts "Dijkstra between a and f"
  r = t.moore_dijkstra(g.a, g.f)
  if r.nil?
    puts "No way !"
  else
    print "\tPath : "; p r[:path]
    puts "\tDistance : #{r[:distance]}"
  end
  
  print "Ranges : "
  rr = t.range
  p rr
  puts "Your graph contains circuits" if rr.include?(nil)
  
  puts "Critical path : "
  rrr = t.critical_path
  print "\tPath "; p rrr[:path]
  puts "\tDistance : #{rrr[:distance]}"

== INSTALLATION

  sudo gem install ruby-graphviz

You also need to install GraphViz[http://www.graphviz.org] 

On *Windows* you also need to install win32-open3. This is not an absolute requirement.

== LICENCES

=== Ruby/GraphViz 

Ruby/GraphViz is freely distributable according to the terms of the
GNU General Public License (see the file 'COPYING').

This program is distributed without any warranty. See the file
'COPYING' for details.

GNU General Public Licence: http://en.wikipedia.org/wiki/Gpl

=== nothugly.xsl

By Vidar Hokstad and Ryan Shea; Contributions by Jonas Tingborn,
Earl Cummings, Michael Kennedy (Graphviz 2.20.2 compatibility, bug fixes, testing, lots of gradients)

Copyright (c) 2009 Vidar Hokstad

Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to deal
in the Software without restriction, including without limitation the rights
to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
copies of the Software, and to permit persons to whom the Software is
furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in
all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
THE SOFTWARE.

MIT license: http://en.wikipedia.org/wiki/MIT_License