DO NOT USE THIS YET! THE NUMPY CODE WAS ONLY THE FIRST STEP, AND DOESN'T MAKE THINGS ANY FASTER YET. THINGS WILL BE FASTER ONCE I DO SOME STRING PROCESSING FIXES.
Skeinforge invokes a love/hate relationship. We love it for actually doing a very difficult job, and making it possible for us to build things on our 3d printer, but we hate it's obtuse interface, overwhelming complexity, and SLOW PERFORMANCE.
That isn't a dig btw, fabmetheus did a good job of optimizing what is there. Any attempt to speed things up is going to need alternative approaches, coz this is really as fast as stock python math can get without some serious tweaking.