On 10/31/2011 11:48 AM, mark florisson wrote: > On 31 October 2011 10:03, Dag Sverre Seljebotn > <d.s.seljeb...@astro.uio.no> wrote: >> Mark: I'm just wondering what you wanted to do with NumPy from Cython -- a >> stopgap solution for SIMD, iterator support, or something else? >> >> SIMD using NumPy really isn't the best idea long-term because of all the >> temporaries needed in compound expressions, which is really bad on the >> memory bus for anything but tiny arrays. For that I'd rather look at finding >> a nogil core of numexpr or similar. > > Yes I'm aware of numexpr and the general problem with array > expressions in NumPy. It's not just about SIMD or iterators, it's as > you say below, there's lots of stuff that wouldn't be available even > if we get SIMD. And if NumPy would get such an API, Cython could > figure out how many (or if) temporaries are actually needed and call > into the NumPy API with inplace operations. > > The thing is, how much of NumPy (and numexpr or theano) does Cython > want to reimplement? Will you stop at SIMD with elemental functions? > And will it run on my GPU? > > I suppose from a purity perspective I'd just like this functionality > to be available in a library and have my language use the library > efficiently behind my back, instead of implementing everything itself.
I do totally agree, but I'm also afraid that this is a neverending quest as long as the GIL is present in CPython. There will always be stuff I'd like to call without the GIL. Only NumPy is not sufficient; I'd also like to use all the scientific libraries which relies on and extends NumPy (all of SciPy for starters), and so on. I do feel that what we have + SIMD covers just enough situations that it is useful for writing "numerical cores", without needing the rest of NumPy. If one starts to pull in more conveniences then I feel I might equally likely need something in SciPy. I'm not really against what you try to do; any progress at all on how much one can do without the GIL is great, I'm just playing the devil's advocate for a bit. Dag Sverre _______________________________________________ NumPy-Discussion mailing list NumPy-Discussion@scipy.org http://mail.scipy.org/mailman/listinfo/numpy-discussion
