[Numpy-discussion] NEP for faster ufuncs

Francesc Alted faltet@pytables....
Wed Dec 22 11:07:13 CST 2010


A Wednesday 22 December 2010 17:25:13 Mark Wiebe escrigué:
> Can you print out your np.__version__, and try running the tests?  If
> newiter didn't build for some reason, its tests should be throwing a
> bunch of exceptions.

I'm a bit swamped now.  Let's see if I can do that later on.

> > I see :-)  Well, I'd think that numexpr is not specially efficient
> > when handling broadcasting, so this might be the reason your
> > approach is faster.  I suppose that with operands with the same
> > shape, things might look different.
> 
> I haven't looked at the numexpr code, but I think the ufuncs will
> need SSE versions to make up part of the remaining difference.

Uh, I doubt that SSE can do a lot for accelerating operations like 
3*a+b-(a/c), as this computation is mainly bounded by memory (although 
threading does certainly help).  Numexpr can use SSE only via Intel's 
VML, which is very good for accelerating the computation of 
transcendental functions (sin, cos, sqrt, exp, log...).

-- 
Francesc Alted


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