Instead of a 1.8MB file, I get a 14KB file. Instead of taking 10 seconds to produce, it takes an unnoticably small time. It's a heck of a lot faster to load, and it's much easier to understand. Anyway, now that I've got the layout algorithm working, I can start adding in the node visualisations so that the graphic is actually linked to the main web-site and reflects current status.