[SciPy-dev] [Numpy-discussion] Tuning sparse stuff in NumPy

[Robert Cimrman]

David Koch wrote:
> Ok,
> 
> I did and the results are:
> csc * csc: 372.601957083
> csc * csc: 3.90811300278

a typo here? which one is csr?

> csr * csc: 15.3202679157
> csr * csr:  3.84498214722
> 
> Mhm, quite insightful. Note, that in an operation X.transpose() * X,
> where X
> is csc_matrix, then X.tranpose() is automatically cast to csr_matrix. A
> re-cast to csc make the whole operation faster. It's still about 1000 times
> slower than Matlab but 4 times faster than before.

ok. now which version of scipy (scipy.__version__) do you use (you may
have posted it, but I missed it)? Not so long ago, there was an effort
by Nathan Bell and others reimplementing sparsetools + scipy.sparse to
get better usability and performance. My (almost latest) version is
0.5.3.dev2860.

r.