I have updated the Google Code repository with updates to integrate GraphViz. It expects the PEAR GraphViz package to be installed.  To install it, issue command:

<h1>You must install the beta package.</h1>

sudo pear install Image_GraphViz-beta

If you’d rather not mess with PEAR, download the package, extract the class Image_GraphViz, and alter two two lines of code that depend on the PEAR::System package. It should be trivial to change these. They are both basically calls like this:

// create a temporary file with the prefix "graph_"
$file = System::mktemp('graph_');

One possible replacement:

// will use default tmp dir
$file = tempnam('', 'graph_');