[Numpy-discussion] efficient 3d histogram creation

Dag Sverre Seljebotn dagss at student.matnat.uio.no
Thu May 7 07:32:03 EDT 2009


Stéfan van der Walt wrote:
> 2009/5/7 Chris Colbert <sccolbert at gmail.com>:
>> This was really my first attempt at doing anything constructive with Cython.
>> It was actually unbelievably easy to work with. I think i spent less time
>> working on this, than I did trying to find an optimized solution using pure
>> numpy and python.
> 
> One aspect we often overlook is how easy it is to write a for-loop in
> comparison to vectorisation.  Besides, for-loops are sometimes easier
> to read as well!
> 
> I think the Cython guys are planning some sort of templating, but I'll
> CC Dag so that he can tell us more.

We were discussing how it would/should look like, but noone's committed 
to implementing it so it's pretty much up in the blue I think -- someone 
might jump in and do it next week, or it might go another year, I can't 
tell.

While I'm here, also note in that code Chris wrote that you want to pay 
attention to the change of default division semantics on Cython 0.12 
(especially for speed).

http://wiki.cython.org/enhancements/division

-- 
Dag Sverre



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