Hi,

Something related. A while ago I was using sparse matrices
to compute the page ranks of a small web. The computation
was *much* too slow. So I implemented my own method
for "matrix" x "vector" as a simple loop through the non-zero entries
of "martrix" which was *much* faster.

So: question: could it be that the multiplication of sparse matrices
is not as optimized as it should be? I looked in
"matrix_generic_sparse.pyx"
but I don't even see a _mul_ method. Where is multiplication
of sparse matrices implemented?

Michel


On Jun 2, 4:23 am, "Mike Hansen" <[EMAIL PROTECTED]> wrote:
> I thought I recalled someone mentioning this before, but is someone
> working on or thinking about working on implementing "sparse" block
> diagonal matrices where you would only store the dense blocks?
>
> If someone is working on it, I'd be willing to help out a bit since it
> would be incredibly useful for some of my research.
>
> --Mike


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