Just store B as AIJ. The huge amount of work and communication for the dense matrix matrix product will totally swamp out the little extra overhead of using AIJ instead of writing custom code for B*C.
Barry > On Jun 20, 2018, at 12:40 PM, Michael Povolotskyi <[email protected]> wrote: > > Dear Petsc team, > > what would be the most efficient way to compute the following: > > V += A*B*C, > > where V is a dense square matrix, > > B is a square diagonal matrix, A and C are dense rectangular matrices? > > I would like to benefit from the fact that B is diagonal. > > thank you, > > Michael. >
