C is it always faster than nump?

[BELAHCENE Abdelkader]

Thanks every body,
I want to close the subject, but just a naive question:
Does numpy use  a* vectorization *for arrays?
I mean when I add 2 arrays ( or in sum function) how it is done,
in an other word
b=np.arange(100);
 t=np.sum(b)
is equivalent or not to
 s=0
for i in range(100): s +=b[i]
thanks a lot


Le sam. 26 févr. 2022 à 06:44, Dan Stromberg <drsalists at gmail.com> a écrit :

>
> On Fri, Feb 25, 2022 at 8:12 AM BELAHCENE Abdelkader <
> abdelkader.belahcene at enst.dz> wrote:
>
>> Hi,
>> a lot of people think that C (or C++) is faster than python, yes I agree,
>> but I think that's not the case with numpy, I believe numpy is faster than
>> C, at least in some cases.
>>
>
> This is all "last time I heard".
>
> numpy is written, in significant part, in Fortran.
>
> Fortran, especially for matrix math with variable dimensions, can be
> faster than C.
>
> Fortran, (still last I heard) did not support pointers, which gives
> Fortran compilers the chance to exploit a very nice class of optimizations
> you can't use nearly as well in languages with pointers.
>
> I used to code C to be built with the "noalias" optimization, to get much
> of the speed of Fortran in C.  But it required using an error prone subset
> of C without good error detection.
>
>
>