void PETSc::Solve(void)
{
//start_clock("Before Assemble matrix and vector");
ierr = MatAssemblyBegin(A,MAT_FINAL_ASSEMBLY);
ierr = MatAssemblyEnd(A,MAT_FINAL_ASSEMBLY);
ierr = VecAssemblyBegin(x);
ierr = VecAssemblyEnd(x);
ierr = VecAssemblyBegin(b);
ierr = VecAssemblyEnd(b);
//stop_clock("After Assembly matrix and vector");
KSPSetOperators(ksp,A,A,DIFFERENT_NONZERO_PATTERN);
KSPSetType(ksp,KSPBCGSL);
KSPBCGSLSetEll(ksp,2);
//KSPGetPC(ksp, &pc);
//PCSetType(pc, PCJACOBI);
KSPSetFromOptions(ksp);
KSPSetUp(ksp);
//start_clock("Before KSPSolve");
KSPSolve(ksp,b,x);
//stop_clock("After KSPSolve");
}
PetscErrorCode KSPSetFromOptions_BCGSL(KSP ksp)
{
KSP_BCGSL *bcgsl = (KSP_BCGSL *)ksp->data;
PetscErrorCode ierr;
PetscInt this_ell;
PetscReal delta;
PetscTruth flga = PETSC_FALSE, flg;
PetscFunctionBegin;
/* PetscOptionsBegin/End are called in KSPSetFromOptions. They
don't need to be called here.
*/
ierr = PetscOptionsHead("KSP BiCGStab(L) Options");
CHKERRQ(ierr);
/* Set number of search directions */
ierr = PetscOptionsInt("-ksp_bcgsl_ell","Number of Krylov search directions","KSPBCGSLSetEll",bcgsl->ell,&this_ell,&flg);
CHKERRQ(ierr);
if (flg) {
ierr = KSPBCGSLSetEll(ksp, this_ell);
CHKERRQ(ierr);
}
/* Set polynomial type */
ierr = PetscOptionsTruth("-ksp_bcgsl_cxpoly", "Polynomial part of BiCGStabL is MinRes + OR", "KSPBCGSLSetPol", flga,&flga,PETSC_NULL);
CHKERRQ(ierr);
if (flga) {
ierr = KSPBCGSLSetPol(ksp, PETSC_TRUE);
CHKERRQ(ierr);
} else {
flg = PETSC_FALSE;
ierr = PetscOptionsTruth("-ksp_bcgsl_mrpoly", "Polynomial part of BiCGStabL is MinRes", "KSPBCGSLSetPol", flg,&flg,PETSC_NULL);
CHKERRQ(ierr);
ierr = KSPBCGSLSetPol(ksp, PETSC_FALSE);
CHKERRQ(ierr);
}
/* Will computed residual be refreshed? */
ierr = PetscOptionsReal("-ksp_bcgsl_xres", "Threshold used to decide when to refresh computed residuals", "KSPBCGSLSetXRes", bcgsl->delta, &delta, &flg);
CHKERRQ(ierr);
if (flg) {
ierr = KSPBCGSLSetXRes(ksp, delta);
CHKERRQ(ierr);
}
ierr = PetscOptionsTail();
CHKERRQ(ierr);
PetscFunctionReturn(0);
}
void PETSc::Solve_withPureNeumann(void)
{
ierr = MatAssemblyBegin(A,MAT_FINAL_ASSEMBLY);
ierr = MatAssemblyEnd(A,MAT_FINAL_ASSEMBLY);
ierr = VecAssemblyBegin(x);
ierr = VecAssemblyEnd(x);
ierr = VecAssemblyBegin(b);
ierr = VecAssemblyEnd(b);
MatNullSpaceCreate(PETSC_COMM_WORLD,PETSC_TRUE,0,PETSC_NULL,&nullsp);
KSPSetNullSpace(ksp,nullsp);
KSPSetOperators(ksp,A,A,DIFFERENT_NONZERO_PATTERN);
//KSPSetType(ksp,KSPMINRES);
//KSPSetType(ksp,KSPGMRES);
//KSPSetType(ksp,KSPBCGS);
KSPSetType(ksp,KSPBCGSL);
KSPBCGSLSetEll(ksp,2);
//KSPGetPC(ksp, &pc);
//PCSetType(pc, PCASM);
//PCSetType(pc, PCMG);
//PCMGSetLevels(pc, 3, &PETSC_COMM_WORLD);
//PCMGSetType(pc,PC_MG_MULTIPLICATIVE);
//PCMGSetCycleType(pc,PC_MG_CYCLE_V);
//
KSPSetFromOptions(ksp);
KSPSetUp(ksp);
//start_clock("Before Petsc Solve in pure neumann solver");
KSPSolve(ksp,b,x);
//stop_clock("After Petsc Solve in pure neumann solver");
}
void PETSC_STDCALL kspbcgslsetell_(KSP ksp,PetscInt *ell, int *__ierr ){
*__ierr = KSPBCGSLSetEll(
(KSP)PetscToPointer((ksp) ),*ell);
}
