void Solve_Distance(UserCtx *user, int iter)
{
SNES snes_distance;
KSP ksp;
PC pc;
Vec r;
Mat J;
double norm;
int bi=0;
VecDuplicate(LevelSet, &r);
SNESCreate(PETSC_COMM_WORLD,&snes_distance);
SNESSetFunction(snes_distance,r,FormFunction_Distance,(void *)&user[bi]);
MatCreateSNESMF(snes_distance, &J);
SNESSetJacobian(snes_distance,J,J,MatMFFDComputeJacobian,(void *)&user[bi]);
SNESSetType(snes_distance, SNESTR); //SNESTR,SNESLS
double tol=1.e-2;
SNESSetMaxLinearSolveFailures(snes_distance,10000);
SNESSetMaxNonlinearStepFailures(snes_distance,10000);
SNESKSPSetUseEW(snes_distance, PETSC_TRUE);
SNESKSPSetParametersEW(snes_distance,3,PETSC_DEFAULT,PETSC_DEFAULT,PETSC_DEFAULT,PETSC_DEFAULT,PETSC_DEFAULT,PETSC_DEFAULT);
SNESSetTolerances(snes_distance,PETSC_DEFAULT,tol,PETSC_DEFAULT,5,50000); // snes iter
SNESGetKSP(snes_distance, &ksp);
KSPSetType(ksp, KSPGMRES);
//KSPGMRESSetPreAllocateVectors(ksp);
KSPGetPC(ksp,&pc);
PCSetType(pc,PCNONE);
//int maxits=10;
int maxits=4; // ksp iter
double rtol=tol, atol=PETSC_DEFAULT, dtol=PETSC_DEFAULT;
KSPSetTolerances(ksp,rtol,atol,dtol,maxits);
extern PetscErrorCode MySNESMonitor(SNES snes,PetscInt n,PetscReal rnorm,void *dummy);
SNESMonitorSet(snes_distance,MySNESMonitor,PETSC_NULL,PETSC_NULL);
SNESSolve(snes_distance, PETSC_NULL, LevelSet);
SNESGetFunctionNorm(snes_distance, &norm);
//PetscPrintf(PETSC_COMM_WORLD, "\nDistance SNES residual norm=%.5e\n\n", norm);
VecDestroy(r);
MatDestroy(J);
SNESDestroy(snes_distance);
};
void
petscSetDefaults(FEProblem & problem)
{
// dig out Petsc solver
NonlinearSystem & nl = problem.getNonlinearSystem();
PetscNonlinearSolver<Number> * petsc_solver = dynamic_cast<PetscNonlinearSolver<Number> *>(nl.sys().nonlinear_solver.get());
SNES snes = petsc_solver->snes();
KSP ksp;
SNESGetKSP(snes, &ksp);
PCSide pcside = getPetscPCSide(nl.getPCSide());
#if PETSC_VERSION_LESS_THAN(3,2,0)
// PETSc 3.1.x-
KSPSetPreconditionerSide(ksp, pcside);
#else
// PETSc 3.2.x+
KSPSetPCSide(ksp, pcside);
#endif
SNESSetMaxLinearSolveFailures(snes, 1000000);
#if PETSC_VERSION_LESS_THAN(3,0,0)
// PETSc 2.3.3-
KSPSetConvergenceTest(ksp, petscConverged, &problem);
SNESSetConvergenceTest(snes, petscNonlinearConverged, &problem);
#else
// PETSc 3.0.0+
// In 3.0.0, the context pointer must actually be used, and the
// final argument to KSPSetConvergenceTest() is a pointer to a
// routine for destroying said private data context. In this case,
// we use the default context provided by PETSc in addition to
// a few other tests.
{
PetscErrorCode ierr = KSPSetConvergenceTest(ksp,
petscConverged,
&problem,
PETSC_NULL);
CHKERRABORT(nl.comm().get(),ierr);
ierr = SNESSetConvergenceTest(snes,
petscNonlinearConverged,
&problem,
PETSC_NULL);
CHKERRABORT(nl.comm().get(),ierr);
}
#endif
}
