Sparse matrices

[positiveblue]

Hello @poulson,

I would like to know which is the current state of the suite for sparse matrices in libElemental.

I have been checking some old issues and the documentation for 0.86-dev but I think is a bit out of date. For example, I saw a function to multiply a vector and a sparse matrix, is there any version for Sparse Elemental Matrix * X (where X is a Dense Elemental Matrix or a Sparse Elemental Matrix)?

Is there any document where I can find a more updated version of what can/can't be done with sparse matrices?

Thanks.

[poulson]

Unfortunately there is no such document. I will try to respond in more detail after I finish work tonight and finish a subsequent conf. call.

The short answer is that I am planning to reboot the project from scratch in the coming few months with lessons learned with clean IP. In the mean time I havent felt much like working on docs.

[BenBrock]

Can anyone comment on whether it's possible to multiply two sparse matrices together in Elemental? Or, for that matter, multiply a sparse matrix by a dense matrix?

It appears Gemm only works with dense matrices.

[poulson]

@BenBrock There is no distributed support for composing sparse matrices in Elemental. I recommend looking into the Combinatorial BLAS project for that. There is support for distributed multiplication of sparse matrices by dense matrices (see the Multiply routine).

But, more importantly, no one has stepped up to maintain this project and I moved on literally years ago (though am developing again at https://gitlab.com/hodge_star). You might ping the folks at Livermore who forked the project at https://github.com/llnl/elemental.

[BenBrock]

Thanks for the quick response! Exactly the information I needed.