Hi Ivo,
On 18 Jul., 13:32, hedtke <hed...@me.com> wrote:
> I know Strassen-Winograd. Strassen uses 18 additions, Strassen-Winograd only
> 15, which is optimal for 7 multiplications ;-)
Looking at sage.matrix.strassen.strassen_multiply_window, I find 15
additions/subtractions. So, it seems that Strassen==Strassen-Winograd
in Sage.
> With the in-memory variant I mean: "Boyer, Dumans, Pernet and Zhou: Memory
> efficient scheduling of Strassen-Winograd's matrix multiplication algorithm.
> International Symposium on Symbolic and Algebraic Computation 2009."
I am not so sure about the memory efficiency of the implementation,
though. One comment says
# todo: we can probably save some memory in these
# operations by reusing some of the buffers, if we interleave
# these additions with the multiplications (below)
Moreover, the algorithm is called recursively, which probably means
that there are a lot of temporary variables stored in memory.
Thank you for the pointer to a memory efficient version!
Best regards,
Simon
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