Both matrices (A and B) would be approximately the same size and large. The use case (for me at least) is to create several large sparse matrices which will be combined in various ways through Kronecker products. The combination happens at every time step in an evolution, so it really needs to be fast as well. I’m thinking mpi/petsc is probably not the most optimal way for dealing with this, and might just have to work with single node multi-threading.
Best, Tyler From: Matthew Knepley <[email protected]> Date: Monday, January 30, 2023 at 11:31 AM To: Guglielmo, Tyler Hardy <[email protected]> Cc: Barry Smith <[email protected]>, [email protected] <[email protected]> Subject: Re: [petsc-users] Kronecker Product On Mon, Jan 30, 2023 at 2:24 PM Guglielmo, Tyler Hardy via petsc-users <[email protected]<mailto:[email protected]>> wrote: Thanks Barry, I saw that function, but wasn’t sure how to apply it since the documentation says that S and T are dense matrices, but in my case all matrices involved are sparse. Is there a way to work around the dense requirement? We don't have parallel sparse-sparse. It would not be too hard to write, but it would be some work. It is hard to understand the use case. Is one matrix much smaller? If not, and you inherit the distribution from A, it seems like it might be very suboptimal, and otherwise you would have to redistribute on the fly and it would get very complicated. Thanks, Matt Best, Tyler From: Barry Smith <[email protected]<mailto:[email protected]>> Date: Monday, January 30, 2023 at 11:12 AM To: Guglielmo, Tyler Hardy <[email protected]<mailto:[email protected]>> Cc: [email protected]<mailto:[email protected]> <[email protected]<mailto:[email protected]>> Subject: Re: [petsc-users] Kronecker Product Do you need the explicit sparse representation of the Kronecker product? Or do you want to apply it as an operator or solve systems with it? If the latter you can use https://petsc.org/release/docs/manualpages/Mat/MatCreateKAIJ/#matcreatekaij<https://urldefense.us/v3/__https:/petsc.org/release/docs/manualpages/Mat/MatCreateKAIJ/*matcreatekaij__;Iw!!G2kpM7uM-TzIFchu!lSQ9WFlYi6PMdfs3WAfEq4ydgCLZtfDgyFy9PjdLNTisCsHtwmVuukcpIv1J0i1EtiQ$> Barry On Jan 30, 2023, at 12:53 PM, Guglielmo, Tyler Hardy via petsc-users <[email protected]<mailto:[email protected]>> wrote: Hi all, I am wondering if there is any functionality for taking Kronecker products of large sparse matrices that are parallel? MatSeqAIJKron is as close as I have found, but it seems like this does not work for parallel matrices. Any ideas here? An option could be to make A and B sequential, compute the Kronecker product, C, then scatter C into a parallel matrix? This seems like a horribly inefficient procedure. I’m still fairly new to petsc, so thanks for patience :)! Best, Tyler +++++++++++++++++++++++++++++ Tyler Guglielmo Postdoctoral Researcher Lawrence Livermore National Lab Office: 925-423-6186 Cell: 210-480-8000 +++++++++++++++++++++++++++++ -- What most experimenters take for granted before they begin their experiments is infinitely more interesting than any results to which their experiments lead. -- Norbert Wiener https://www.cse.buffalo.edu/~knepley/<https://urldefense.us/v3/__http:/www.cse.buffalo.edu/*knepley/__;fg!!G2kpM7uM-TzIFchu!nK03nUENfNtHoOs8RWmJWJQYJH2IlC_lYQPNn7kV9FsBv2CQKR_VSqbLGRLFShVpKmY$>
