PetscErrorCode SNESSetFromOptions_NGS(SNES snes)
{
SNES_NGS *gs = (SNES_NGS*)snes->data;
PetscErrorCode ierr;
PetscInt sweeps,max_its=PETSC_DEFAULT;
PetscReal rtol=PETSC_DEFAULT,atol=PETSC_DEFAULT,stol=PETSC_DEFAULT;
PetscBool flg,flg1,flg2,flg3;
PetscFunctionBegin;
ierr = PetscOptionsHead("SNES GS options");CHKERRQ(ierr);
/* GS Options */
ierr = PetscOptionsInt("-snes_ngs_sweeps","Number of sweeps of GS to apply","SNESComputeGS",gs->sweeps,&sweeps,&flg);CHKERRQ(ierr);
if (flg) {
ierr = SNESNGSSetSweeps(snes,sweeps);CHKERRQ(ierr);
}
ierr = PetscOptionsReal("-snes_ngs_atol","Number of sweeps of GS to apply","SNESComputeGS",gs->abstol,&atol,&flg);CHKERRQ(ierr);
ierr = PetscOptionsReal("-snes_ngs_rtol","Number of sweeps of GS to apply","SNESComputeGS",gs->rtol,&rtol,&flg1);CHKERRQ(ierr);
ierr = PetscOptionsReal("-snes_ngs_stol","Number of sweeps of GS to apply","SNESComputeGS",gs->stol,&stol,&flg2);CHKERRQ(ierr);
ierr = PetscOptionsInt("-snes_ngs_max_it","Number of sweeps of GS to apply","SNESComputeGS",gs->max_its,&max_its,&flg3);CHKERRQ(ierr);
if (flg || flg1 || flg2 || flg3) {
ierr = SNESNGSSetTolerances(snes,atol,rtol,stol,max_its);CHKERRQ(ierr);
}
flg = PETSC_FALSE;
ierr = PetscOptionsBool("-snes_ngs_secant","Use pointwise secant local Jacobian approximation","",flg,&flg,NULL);CHKERRQ(ierr);
if (flg) {
ierr = SNESSetNGS(snes,SNESComputeNGSDefaultSecant,NULL);CHKERRQ(ierr);
ierr = PetscInfo(snes,"Setting default finite difference coloring Jacobian matrix\n");CHKERRQ(ierr);
}
ierr = PetscOptionsReal("-snes_ngs_secant_h","Differencing parameter for secant search","",gs->h,&gs->h,NULL);CHKERRQ(ierr);
ierr = PetscOptionsBool("-snes_ngs_secant_mat_coloring","Use the Jacobian coloring for the secant GS","",gs->secant_mat,&gs->secant_mat,&flg);CHKERRQ(ierr);
ierr = PetscOptionsTail();CHKERRQ(ierr);
PetscFunctionReturn(0);
}
PETSC_EXTERN void PETSC_STDCALL snesngssettolerances_(SNES snes,PetscReal *abstol,PetscReal *rtol,PetscReal *stol,PetscInt *maxit, int *__ierr ){
*__ierr = SNESNGSSetTolerances(
(SNES)PetscToPointer((snes) ),*abstol,*rtol,*stol,*maxit);
}
