punkish has asked for the wisdom of the Perl Monks concerning the following question:

I have a sample data structure like so -- 

%d = (
  a => [b,c,d,],
  b => [a,d,],
  c => [b,d,e,],
);
and so on...

[download]

I would like to create a directed graph (I believe I am using the term correctly) and visualize it such that... 

makeGraph('a');

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will create a "picture" with 'a' as the origin and arrows to b, c, and d... clicking on, say, 'b' will call makeGraph('b'), and so on.

I believe I can accomplish this with Graphviz family of modules, but there are two problems with Graphviz... one, the output is pretty, how shall I say this politely, not nice. Maybe that can be adjusted with further exploration. But, more than that, it is really a static picture. Ideally I would like one of those springy network visualizations that one sees on Amazon and C|Net, etc. (www.touchgraph.com has a nice WikiBrowser that does something like this, except, in a standalone app... eventually I want this to work in a browser). I realize this would have to be done in something like Java (www.processing.org comes to mind), but perhaps I can do the coding in Perl, and then send off the data to the Java applet.

In any case, I am looking for some starting directions here.

Many thanks,

--

when small people start casting long shadows, it is time to go to bed

Replies are listed 'Best First'.
Re: drawing (visualizing) directed graphs
by NetWallah (Canon) on Jul 15, 2006 at 02:43 UTC
    I have tested this lightly, and Graph::Easy seems to work - it should meet your requirements. It can "Render graphs as ASCII, HTML, SVG or Graphviz".

    From the docs: 

     use Graph::Easy;
        
        my $graph = Graph::Easy->new();

       $graph->add_edge_once ('Bonn', 'Berlin');

        print $graph->as_ascii( );

        # prints:

        # +------+     +--------+
        # | Bonn | --> | Berlin |
        # +------+     +--------+

    [download]
    There is a tutorial,and samples, at the author's website.

         "For every complex problem, there is a simple answer ... and it is wrong." --H.L. Mencken

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Re: drawing (visualizing) directed graphs
by lima1 (Curate) on Jul 15, 2006 at 08:30 UTC
    I evaluated a bunch of tools. I ended up using the yed editor and generating a XML file for yed in my perl scripts. yed comes with a lot of different layout modules. looks great.
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Re: drawing (visualizing) directed graphs
by planetscape (Chancellor) on Jul 15, 2006 at 09:26 UTC

    Mastering Algorithms in Perl has an entire chapter (8) devoted to Graphs; you may be able to find something useful in the sample code. (The end of the chapter also has an overview of graph-related CPAN modules.)

    HTH,

    planetscape
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      Mastering Algorithms in Perl has an entire chapter (8) devoted to Graphs

      but nothing about graph drawing. I don't know any open source library that produces good looking graphs - for all type of graphs, not only some special cases.

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