On Fri, 13 Sep 2013, Riccardo (Jack) Lucchetti wrote:
 From some experimenting, it would seem that time is approximately 
 quadratic; I suppose we could try something to make it less convex [...] 
I've committed a change to CVS which should help a lot with the speed for 
big data. But it may be a bit rough around the edges; I (or others) need 
to do some more testing to make sure I haven't broken anything.
Allin