"multigrid as a solver" generally means stationary (Richardson) iterations: -ksp_type richardson -pc_type hypre
This might not converge, and you'll almost certainly see faster convergence if you use it with a Krylov method. -ksp_type cg -pc_type hypre if your problem is SPD. sijie tang <[email protected]> writes: > Hi, > > I have a question about, I want to use AMG as a solver in PETSc, but from the > user manual, I find that AMG only can be used as a preconditioner. Am I > right? > > So I want to use the boomerAMG in HYPRE as the solver, Can I use the function > like VecHYPRE_IJVectorCreate (Petsc function) in these links? > > https://petsc.org/release/src/vec/vec/impls/hypre/vhyp.c > <https://petsc.org/release/src/vec/vec/impls/hypre/vhyp.c>. (It Creates > hypre ijvector from Petsc vector) > https://petsc.org/main/src/mat/impls/hypre/mhypre.c.html > <https://petsc.org/main/src/mat/impls/hypre/mhypre.c.html> (It Creates > hypre ijmatrix from Petsc matrix) > > > But there is a another question: how to transfer the vector/matrix structure > from hypre back petsc ? > > I don’t find any function for that work, Do you know what function can work, > or do I implement this function by myself? > > > > Thanks, > Sijie
