Re: [petsc-users] Using MatCreateComposite with petsc4py

[Pierre Jolivet]

On 2 Dec 2024, at 11:15 PM, Eric Chamberland via petsc-users <petsc-users@mcs.anl.gov> wrote:  Hello, We were exploring the use of the MatCreateComposite function with petsc4py, but we noticed that it doesn't seem to be available in the Python interface (https://petsc.org/release/petsc4py/reference/petsc4py.PETSc.Mat.html). We were wondering if this is due to a technical limitation or if there is a better alternative to achieve the same result. Our goal is to create a matrix representing $P^{T}AP$ without explicitly computing the product. We also considered using MatShell, but it seems that this approach is not supported in petsc4py either. What do you mean? You can use either a MatShell or a MatPython in petsc4py out of the box. Thanks, Pierre  On the other hand, we noticed that MatCreateTranspose is implemented, and it aligns somewhat with the kind of operation we're aiming for. Any insights or advice you could provide would be greatly appreciated! Thank you, Eric -- Eric Chamberland, ing., M. Ing Professionnel de recherche GIREF/Université Laval (418) 656-2131 poste 41 22 42