I have no answer to the question, but I was curious as to why directly calling the cblas would be 10x-20x slower in the first place. That seems surprising, although I'm just learning about python numerics.
On Mon, Feb 18, 2013 at 7:38 AM, Sergio Callegari < sergio.calleg...@gmail.com> wrote: > Hi, > > I have a project that includes a cython script which in turn does some > direct > access to a couple of cblas functions. This is necessary, since some matrix > multiplications need to be done inside a tight loop that gets called > thousands > of times. Speedup wrt calling scipy.linalg.blas.cblas routines is 10x to > 20x. > > Now, all this is very nice on linux where the setup script can assure that > the > cython code gets linked with the atlas dynamic library, which is the same > library that numpy and scipy link to on this platform. > > However, I now have trouble in providing easy ways to use my project in > windows. All the free windows distros for scientific python that I have > looked at (python(x,y) and winpython) seem to repackage the windows > version of > numpy/scipy as it is built in the numpy/scipy development sites. These > appear > to statically link atlas inside some pyd files. So I get no atlas to link > against, and I have to ship an additional pre-built atlas with my project. > > All this seems somehow inconvenient. > > In the end, when my code runs, due to static linking I get 3 replicas of 2 > slightly different atlas libs in memory. One coming with _dotblas.pyd in > numpy, > another one with cblas.pyd or fblas.pyd in scipy. And the last one as the > one > shipped in my code. > > Would it be possible to have a win distro of scipy which provides some > pre built atlas dlls, and to have numpy and scipy dynamically link to them? > This would save memory and also provide a decent blas to link to for things > done in cython. But I believe there must be some problem since the scipy > site > says > > "IMPORTANT: NumPy and SciPy in Windows can currently only make use of > CBLAS and > LAPACK as static libraries - DLLs are not supported." > > Can someone please explain why or link to an explanation? > > Unfortunately, not having a good, prebuilt and cheap blas implementation in > windows is really striking me as a severe limitation, since you loose the > ability to prototype in python/scipy and then move to C or Cython the major > bottlenecks to achieve speed. > > Many thanks in advance! > > _______________________________________________ > NumPy-Discussion mailing list > NumPy-Discussion@scipy.org > http://mail.scipy.org/mailman/listinfo/numpy-discussion >
_______________________________________________ NumPy-Discussion mailing list NumPy-Discussion@scipy.org http://mail.scipy.org/mailman/listinfo/numpy-discussion
