Graphviz

Draft

Definition

• Graphviz is an open source graph visualization software. It has several main graph layout programs

The dot representation language

• dot guide
• WikiSchool:Graphviz (Tutorial in German)

A directed graph that is represented like this

<graphviz>
digraph G4 {
            "Learning theories" [URL="Learning theory"];
            "Pedagogic strategy" [URL="Pedagogic strategy"];
	    "Instructional design models" [URL="Instructional design model"];
            "Learning theories" -> "Pedagogic strategy";
            "Instructional design models" -> "Pedagogic strategy"
}
</graphviz>

could render like that (yes this wiki has a graphviz extension, but we may not keep it for sure since it is somewhat CPU intensive)

A simple non-directed graph (rendered with neato):

<graphviz renderer='neato' caption='Hello Neato'>
 graph G1 {
    a -- b;
    b -- c;
    a -- c;
}
</graphviz>

gives:

Or a more complex non-directed graph (rendered with neato):

<graphviz renderer='neato' caption='Hello Neato'>
graph G {
   run -- intr;
   intr -- runbl;
   runbl -- run;
   run -- kernel;
   kernel -- zombie;
   kernel -- sleep;
   kernel -- runmem;
   sleep -- swap;
   swap -- runswap;
   runswap -- new;
   runswap -- runmem;
   new -- runmem;
   sleep -- runmem;
}
</graphviz>

like this

Tools

See Graphviz - Graph Visualization Software (a longer list of interfaces, bindings, generators, scripts, etc.). Usually also needs graphviz software and the other way round. I.e. after installing Graphviz, you likely want to install a viewer or generator.

Mediawiki extensions

• GraphViz Widget for Mediawikis (alpha status in Feb 2008).
• Extension:Graphical Category Browser for MediaWiki (>1.7x). This may be outdated.
• http://www.mediawiki.org/wiki/Extension:GraphViz Extension:GraphViz] MediaWiki extension (Tested in this wiki. Worked with Mediawiki version 1.11, Graphviz 2.16.1 on Solaris 10 - DKS/2008)

GraphiViz Viewers

• ZGRViewer. GraphViz/DOT Viewer
• iDot - Incremental Dot Viewer

Installation

• Download of GraphViz software (source and Win/Linux binaries).

• Under Ubuntu I could install it through the package manager (there are quite a lot of dependencies).

• For solaris, you can download a binary from sunfreeware.com plus these: cairo-1.4.10, freetype-2.3.1, glib-2.14.1, graphviz-2.16.1, pango-1.18.2, xrender-0.8.3,expat-2.0.1.

Tutorials and introductions

• Graphviz (Wikipedia)
• An Introduction to GraphWiz, September 10th, 2004 by Mihalis Tsoukalos, Linux Journal