[SciPy-User] Speed up sin/sqrt functions with cython

[Jerome Kieffer]

On Wed, 12 Jan 2011 13:05:25 +0100 (CET)
<g.plantageneto at runbox.com> wrote:

> 
> Hi,
> 
> I am using cython to speed up some computations (btw, thanks a lot to the people who gave me suggestions on a previous thread).
> I don't understand how to apply the fast C-coded sin/sqrt functions to a numpy array.
> I can import from math.h like this:
> 
> cdef extern from "math.h"
>     double sin(double)
> 
> but then I can't use this function on a numpy ndarray, obviously.
> 
> Any ideas? It sounds silly to me to write a cycle on ndarray elements.

it is not ... and you will gain a lot in speed.

-- 
Jérôme Kieffer
On-Line Data analysis / Software Group 
ISDD / ESRF
tel +33 476 882 445