https://petsc.org/release/manualpages/Mat/MatPtAP/ also note that PETSc has a large infrastructure for efficient ways to compute various matrix-matrix operations with a variety of algorithms that can be all accessed by starting with https://petsc.org/release/manualpages/Mat/MatProductCreate/
> On Jul 17, 2023, at 1:13 PM, Karthikeyan Chockalingam - STFC UKRI via > petsc-users <[email protected]> wrote: > > Hello, > > I would like to perform the following operation > > [P^T A P] x’ = P^T f > > Where P is a rectangular matrix and A is a square matrix. All the matrixes > are constructed using MPIAIJ. > > Should I be concerned about the parallel partitioning of the matrix P and A? > > Or can I just go ahead and use MatMatMult to compute [P^T A P]? > > Is there any in-built functionality to perform this operation? > > Kind regards, > Karthik. > > > > > > > > -- > Dr. Karthik Chockalingam > High-Performance Software Engineer > Hartree Centre | Science and Technology Facilities Council > [email protected] > <mailto:[email protected]> > > <image001.png>
