On Thu, Mar 10, 2016 at 3:23 PM, Chih-Hao Chen < [email protected]> wrote:
> Hello PETSc members, > > > Sorry for asking for help about the ASM in petsc4py. > Currently I am using your ASM as my preconditioned in my solver. > I know how to setup the PCASM based on the ex8.c in the following link. > http://www.mcs.anl.gov/petsc/petsc-3.4/src/ksp/ksp/examples/tutorials/ex8.c > > But when using the function “getASMSubKSP” in petsc4py, > I have tried several methods, but still cannot get the subksp from each > mpi. > The subKSPs do not have to do with MPI. On each rank, you get the local KSPs. > Here is the snippet of the code of the function. > > def getASMSubKSP(self): cdef PetscInt i = 0, n = 0 cdef > PetscKSP *p = NULL CHKERR( PCASMGetSubKSP(self.pc, &n, NULL, &p) ) > return [ref_KSP(p[i]) for i from 0 <= i <n] > > > In ex8.c, we could use a “FOR” loop to access the indiivdual subksp. > But in python, could I use “FOR” loop to get all the subksps with: > > subksp[i] = pc.getASMSubKSP[i] > I do not understand this, but I think the answer is no. > Another question is in ex8.c, it seems I don’t need to do any setup to > decompose the RHS vector. > But do I need to decompose the RHS vector with any settings if I don’t use > PETSc solvers but with your preconditioners? > I do not understand what you mean by "decompose the RHS vector". Thanks, Matt > Thanks very much. > > Best, > Chih-Hao > > > -- What most experimenters take for granted before they begin their experiments is infinitely more interesting than any results to which their experiments lead. -- Norbert Wiener
