void PetscPreconditioner::set_petsc_subpreconditioner_type(const PCType type, PC& pc) {
int ierr;
KSP* subksps;
int nlocal;
ierr = PCASMGetSubKSP(pc, &nlocal, PETSC_NULL, &subksps);
CHKERRABORT(MPI_COMM_WORLD, ierr);
PetscReal epsilon = 1.e-16;
for(int i = 0; i < nlocal; i++) {
PC subpc;
ierr = KSPGetPC(subksps[i], &subpc);
CHKERRABORT(MPI_COMM_WORLD, ierr);
ierr = KSPSetTolerances(subksps[i], PETSC_DEFAULT, PETSC_DEFAULT, PETSC_DEFAULT, 1);
CHKERRABORT(MPI_COMM_WORLD, ierr);
ierr = KSPSetFromOptions(subksps[i]);
CHKERRABORT(MPI_COMM_WORLD, ierr);
ierr = PCSetType(subpc, type);
CHKERRABORT(MPI_COMM_WORLD, ierr);
ierr = PCFactorSetZeroPivot(subpc, epsilon);
CHKERRABORT(MPI_COMM_WORLD, ierr);
ierr = PCFactorSetShiftType(subpc, MAT_SHIFT_NONZERO);
CHKERRABORT(MPI_COMM_WORLD, ierr);
}
}
PETSC_EXTERN void PETSC_STDCALL pcasmgetsubksp_(PC *pc,PetscInt *n_local,PetscInt *first_local,KSP *ksp,PetscErrorCode *ierr)
{
KSP *tksp;
PetscInt i,nloc;
CHKFORTRANNULLINTEGER(n_local);
CHKFORTRANNULLINTEGER(first_local);
CHKFORTRANNULLOBJECT(ksp);
*ierr = PCASMGetSubKSP(*pc,&nloc,first_local,&tksp);
if (n_local) *n_local = nloc;
if (ksp) {
for (i=0; i<nloc; i++) ksp[i] = tksp[i];
}
}
void solve_ASM(Mat & A_, const Vec & b_, Vec & x_)
{
PETSC_SAFE_CALL(KSPSetType(ksp,s_type));
// We set the size of x according to the Matrix A
PetscInt row;
PetscInt col;
PetscInt row_loc;
PetscInt col_loc;
PETSC_SAFE_CALL(MatGetSize(A_,&row,&col));
PETSC_SAFE_CALL(MatGetLocalSize(A_,&row_loc,&col_loc));
PC pc;
// We set the Matrix operators
PETSC_SAFE_CALL(KSPSetOperators(ksp,A_,A_));
// We set the pre-conditioner
PETSC_SAFE_CALL(KSPGetPC(ksp,&pc));
PETSC_SAFE_CALL(PCSetType(pc,PCASM));
////////////////
/////////////////////
// PCASMSetLocalSubdomains(pc);
PCASMSetOverlap(pc,5);
KSP *subksp; /* array of KSP contexts for local subblocks */
PetscInt nlocal,first; /* number of local subblocks, first local subblock */
PC subpc; /* PC context for subblock */
PetscBool isasm;
/*
Set runtime options
*/
// KSPSetFromOptions(ksp);
/*
Flag an error if PCTYPE is changed from the runtime options
*/
// PetscObjectTypeCompare((PetscObject)pc,PCASM,&isasm);
// if (!isasm) SETERRQ(PETSC_COMM_WORLD,1,"Cannot Change the PCTYPE when manually changing the subdomain solver settings");
/*
Call KSPSetUp() to set the block Jacobi data structures (including
creation of an internal KSP context for each block).
Note: KSPSetUp() MUST be called before PCASMGetSubKSP().
*/
KSPSetUp(ksp);
/*
Extract the array of KSP contexts for the local blocks
*/
PCASMGetSubKSP(pc,&nlocal,&first,&subksp);
/*
Loop over the local blocks, setting various KSP options
for each block.
*/
for (size_t i = 0 ; i < nlocal ; i++)
{
KSPGetPC(subksp[i],&subpc);
// PCFactorSetFill(subpc,30);
PCFactorSetLevels(subpc,5);
PCSetType(subpc,PCILU);
KSPSetType(subksp[i],KSPRICHARDSON);
KSPSetTolerances(subksp[i],1.e-3,0.1,PETSC_DEFAULT,PETSC_DEFAULT);
}
// if we are on on best solve set-up a monitor function
if (try_solve == true)
{
// for bench-mark we are interested in non-preconditioned norm
PETSC_SAFE_CALL(KSPMonitorSet(ksp,monitor,&vres,NULL));
// Disable convergence check
PETSC_SAFE_CALL(KSPSetConvergenceTest(ksp,KSPConvergedSkip,NULL,NULL));
}
// KSPGMRESSetRestart(ksp,100);
// Solve the system
PETSC_SAFE_CALL(KSPSolve(ksp,b_,x_));
KSPConvergedReason reason;
KSPGetConvergedReason(ksp,&reason);
std::cout << "Reason: " << reason << std::endl;
auto & v_cl = create_vcluster();
// if (try_solve == true)
// {
// calculate error statistic about the solution
solError err = statSolutionError(A_,b_,x_);
if (v_cl.getProcessUnitID() == 0)
{
std::cout << "Method: " << s_type << " " << " pre-conditoner: " << PCJACOBI << " iterations: " << err.its << std::endl;
std::cout << "Norm of error: " << err.err_norm << " Norm infinity: " << err.err_inf << std::endl;
}
// }
}
