John Hunter wrote: > On Wed, Jan 7, 2009 at 5:37 PM, Eric Firing <[email protected]> wrote: > >> A couple small changes speed it up quite a bit: >> >> efir...@manini:~/temp/nnbf$ python test_nnbf.py >> loading data... this could take a while >> testing nnbf... >> 10 trials: mean=0.0150, min=0.0100 >> testing numpy... >> 10 trials: mean=0.0660, min=0.0600 >> >> It is all a matter of keeping Python objects and function calls out of inner >> loops. I suspect there is quite a bit more that could be done in that >> regard, but I haven't looked. > > Much faster, but no longer correct, as you'll see if you uncomment > out the nose test test_neighbors that compare actual vs desired. > > Is the pointer arithmetic correct: > > dataptr + i > > I would have thought perhaps: > > dataptr + i*n > > but this is segfaulting. Do we need to use a stride?
Sorry, I was too hasty. Yes, it seems like i*n should be correct, but it isn't; we are missing something simple and fundamental here. I don't see it immediately, and won't be able to look at it for a while. Eric > > JDH > _______________________________________________ > Numpy-discussion mailing list > [email protected] > http://projects.scipy.org/mailman/listinfo/numpy-discussion _______________________________________________ Numpy-discussion mailing list [email protected] http://projects.scipy.org/mailman/listinfo/numpy-discussion
