[Trilinos-Users] [EXTERNAL] Tpetra::CrsMatrix caching related to C= A^T B and D = A*C

[Siefert, Christopher]

Denis,


If you pass in a matrix with the correct structure, for "C" it will keep the communication and sparsity patterns (and be a lot faster).


-Chris

________________________________
From: Trilinos-Users <trilinos-users-bounces at trilinos.org> on behalf of Denis Davydov <davydden at gmail.com>
Sent: Monday, September 10, 2018 8:07 AM
To: trilinos-users
Subject: [EXTERNAL] [Trilinos-Users] Tpetra::CrsMatrix caching related to C= A^T B and D = A*C

Hi all,

I was looking at the documentation of TPetra and could not immediately see whether or not
something is cached for matrix-matrix products.
Say I have tall and skinny sparse matrices A, B, D and need to calculate the products
  C=A^T B
and
  D = A*C
on each iteration of a non-linear solver.
Both the intersection of sparsities of A and B as well as MPI communication pattern does not change from iteration to iteration.
But it looks like Tpetra::MatrixMatrix::Multiply() will be calculating those things every time anew.
Is it indeed the case or is there some mechanism behind-the-scenes which caches this information?

Regards,
Denis.
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <https://trilinos.org/pipermail/trilinos-users/attachments/20180910/dadf34cb/attachment.html>