You can use MatMatTransposeMult(). Hong ________________________________ From: petsc-users <petsc-users-boun...@mcs.anl.gov> on behalf of Olivier Jamond <olivier.jam...@cea.fr> Sent: Wednesday, September 23, 2020 11:56 AM To: PETSc <petsc-users@mcs.anl.gov> Subject: [petsc-users] Compute C*Ct using MatCreateTranspose for Ct
Hi all, I have a rectangle MPIAIJ matrix C. I would like to compute C*Ct explicitly to solve some ksp(C*Ct) problems using direct solvers or with petsc preconditioners. If I just create a 'shell' Ct: Mat Ct; MatCreateTranspose(C, &Ct); MatMatMult(C, Ct, MAT_INITIAL_MATRIX, PETSC_DEFAULT, &CCt); Then it does not work. I get: [0]PETSC ERROR: No support for this operation for this object type [0]PETSC ERROR: MatMatTransposeMult not supported for A of type mpiaij But if instead of C it was Ct that I have explicitly, then it would work: Mat Ct, CC; MatTranspose(C, MAT_INITIAL_MATRIX, &Ct); MatCreateTranspose(Ct, &CC); // create a 'shell' C from explicit Ct to test MatMatMult(CC, Ct, MAT_INITIAL_MATRIX, PETSC_DEFAULT, &CCt); // this is OK Is there a way to avoid the explicit transposition of the matrix? Many thanks, Olivier Jamond
