Re: [Numpy-discussion] Casting and promotion rules (e.g. int + uint64 => float)

2013-03-11 Thread Sergio Callegari
Thanks for the explanation. Chris Barker - NOAA Federal noaa.gov> writes: > There has been a lot of discussion about casting on this list in the > last couple months -- I suggest you peruse that discussion and see > what conclusions it has lead to. I'll look at it. My message to the ml followe

[Numpy-discussion] Casting and promotion rules (e.g. int + uint64 => float)

2013-03-08 Thread Sergio Callegari
Hi, I have noticed that numpy introduces some unexpected type casts, that are in some cases problematic. A very weird cast is int + uint64 -> float for instance, consider the following snippet: import numpy as np a=np.uint64(1) a+1 -> 2.0 this cast is quite different from what other program

Re: [Numpy-discussion] Calling scipy blas from cython is extremely slow

2013-02-23 Thread Sergio Callegari
Partially fixed. I was messing the row, column order. For some reason this was working in some case. Now I've fixed it and it *always* works. However, it is still slower than the cblas cblas -> 0.69 sec scipy blas -> 0.74 sec Any clue why? ___ Num

Re: [Numpy-discussion] Calling scipy blas from cython is extremely slow

2013-02-23 Thread Sergio Callegari
... and it is not deterministic too... About 1 time over 6 the code calling the scipy blas gives a completely wrong result. How can this be? ___ NumPy-Discussion mailing list NumPy-Discussion@scipy.org http://mail.scipy.org/mailman/listinfo/numpy-discus

[Numpy-discussion] Calling scipy blas from cython is extremely slow

2013-02-23 Thread Sergio Callegari
Hi, following the excellent advice of V. Armando Sole, I have finally succeeded in calling the blas routines shipped with scipy from cython. I am doing this to avoid shipping an extra blas library for some project of mine that uses scipy but has some things coded in cython for extra speed. So fa

Re: [Numpy-discussion] Windows, blas, atlas and dlls

2013-02-22 Thread Sergio Callegari
> > from scipy.linalg.blas import fblas > dgemm = fblas.dgemm._cpointer > sgemm = fblas.sgemm._cpointer > OK, but this gives me a PyCObject. How do I make it a function pointer of the correct type in cython? Thanks again Sergio ___ NumPy-Discussion

[Numpy-discussion] Windows, blas, atlas and dlls

2013-02-18 Thread Sergio Callegari
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 routine