static PetscErrorCode SNESSolve_MS(SNES snes) { SNES_MS *ms = (SNES_MS*)snes->data; Vec X = snes->vec_sol,F = snes->vec_func; PetscReal fnorm; MatStructure mstruct; PetscInt i; PetscErrorCode ierr; PetscFunctionBegin; snes->reason = SNES_CONVERGED_ITERATING; ierr = PetscObjectTakeAccess(snes);CHKERRQ(ierr); snes->iter = 0; snes->norm = 0.; ierr = PetscObjectGrantAccess(snes);CHKERRQ(ierr); if (!snes->vec_func_init_set) { ierr = SNESComputeFunction(snes,X,F);CHKERRQ(ierr); if (snes->domainerror) { snes->reason = SNES_DIVERGED_FUNCTION_DOMAIN; PetscFunctionReturn(0); } } else { snes->vec_func_init_set = PETSC_FALSE; } if (snes->jacobian) { /* This method does not require a Jacobian, but it is usually preconditioned by PBJacobi */ ierr = SNESComputeJacobian(snes,snes->vec_sol,&snes->jacobian,&snes->jacobian_pre,&mstruct);CHKERRQ(ierr); ierr = KSPSetOperators(snes->ksp,snes->jacobian,snes->jacobian_pre,mstruct);CHKERRQ(ierr); } if (ms->norms) { if (!snes->norm_init_set) { ierr = VecNorm(F,NORM_2,&fnorm);CHKERRQ(ierr); /* fnorm <- ||F|| */ if (PetscIsInfOrNanReal(fnorm)) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_FP,"Infinite or not-a-number generated in norm"); } else { fnorm = snes->norm_init; snes->norm_init_set = PETSC_FALSE; } /* Monitor convergence */ ierr = PetscObjectTakeAccess(snes);CHKERRQ(ierr); snes->iter = 0; snes->norm = fnorm; ierr = PetscObjectGrantAccess(snes);CHKERRQ(ierr); SNESLogConvHistory(snes,snes->norm,0); ierr = SNESMonitor(snes,snes->iter,snes->norm);CHKERRQ(ierr); /* set parameter for default relative tolerance convergence test */ snes->ttol = fnorm*snes->rtol; /* Test for convergence */ ierr = (*snes->ops->converged)(snes,snes->iter,0.0,0.0,fnorm,&snes->reason,snes->cnvP);CHKERRQ(ierr); if (snes->reason) PetscFunctionReturn(0); } /* Call general purpose update function */ if (snes->ops->update) { ierr = (*snes->ops->update)(snes,snes->iter);CHKERRQ(ierr); } for (i = 0; i < snes->max_its; i++) { ierr = SNESMSStep_3Sstar(snes,X,F);CHKERRQ(ierr); if (i+1 < snes->max_its || ms->norms) { ierr = SNESComputeFunction(snes,X,F);CHKERRQ(ierr); if (snes->domainerror) { snes->reason = SNES_DIVERGED_FUNCTION_DOMAIN; PetscFunctionReturn(0); } } if (ms->norms) { ierr = VecNorm(F,NORM_2,&fnorm);CHKERRQ(ierr); /* fnorm <- ||F|| */ if (PetscIsInfOrNanReal(fnorm)) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_FP,"Infinite or not-a-number generated in norm"); /* Monitor convergence */ ierr = PetscObjectTakeAccess(snes);CHKERRQ(ierr); snes->iter = i+1; snes->norm = fnorm; ierr = PetscObjectGrantAccess(snes);CHKERRQ(ierr); SNESLogConvHistory(snes,snes->norm,0); ierr = SNESMonitor(snes,snes->iter,snes->norm);CHKERRQ(ierr); /* Test for convergence */ ierr = (*snes->ops->converged)(snes,snes->iter,0.0,0.0,fnorm,&snes->reason,snes->cnvP);CHKERRQ(ierr); if (snes->reason) PetscFunctionReturn(0); } /* Call general purpose update function */ if (snes->ops->update) { ierr = (*snes->ops->update)(snes, snes->iter);CHKERRQ(ierr); } } if (!snes->reason) snes->reason = SNES_CONVERGED_ITS; PetscFunctionReturn(0); }
EXTERN_C_END /* SNESSolve_NCG - Solves a nonlinear system with the Nonlinear Conjugate Gradient method. Input Parameters: . snes - the SNES context Output Parameter: . outits - number of iterations until termination Application Interface Routine: SNESSolve() */ #undef __FUNCT__ #define __FUNCT__ "SNESSolve_NCG" PetscErrorCode SNESSolve_NCG(SNES snes) { SNES_NCG *ncg = (SNES_NCG *)snes->data; Vec X, dX, lX, F, B, Fold; PetscReal fnorm, ynorm, xnorm, beta = 0.0; PetscScalar dXdotF, dXolddotFold, dXdotFold, lXdotF, lXdotFold; PetscInt maxits, i; PetscErrorCode ierr; SNESConvergedReason reason; PetscBool lsSuccess = PETSC_TRUE; SNESLineSearch linesearch; PetscFunctionBegin; snes->reason = SNES_CONVERGED_ITERATING; maxits = snes->max_its; /* maximum number of iterations */ X = snes->vec_sol; /* X^n */ Fold = snes->work[0]; /* The previous iterate of X */ dX = snes->work[1]; /* the preconditioned direction */ lX = snes->vec_sol_update; /* the conjugate direction */ F = snes->vec_func; /* residual vector */ B = snes->vec_rhs; /* the right hand side */ ierr = SNESGetSNESLineSearch(snes, &linesearch); CHKERRQ(ierr); ierr = PetscObjectTakeAccess(snes); CHKERRQ(ierr); snes->iter = 0; snes->norm = 0.; ierr = PetscObjectGrantAccess(snes); CHKERRQ(ierr); /* compute the initial function and preconditioned update dX */ if (!snes->vec_func_init_set) { ierr = SNESComputeFunction(snes,X,F); CHKERRQ(ierr); if (snes->domainerror) { snes->reason = SNES_DIVERGED_FUNCTION_DOMAIN; PetscFunctionReturn(0); } } else { snes->vec_func_init_set = PETSC_FALSE; } if (!snes->norm_init_set) { /* convergence test */ ierr = VecNorm(F, NORM_2, &fnorm); CHKERRQ(ierr); /* fnorm <- ||F|| */ if (PetscIsInfOrNanReal(fnorm)) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_FP,"Infinite or not-a-number generated in norm"); } else { fnorm = snes->norm_init; snes->norm_init_set = PETSC_FALSE; } ierr = PetscObjectTakeAccess(snes); CHKERRQ(ierr); snes->norm = fnorm; ierr = PetscObjectGrantAccess(snes); CHKERRQ(ierr); SNESLogConvHistory(snes,fnorm,0); ierr = SNESMonitor(snes,0,fnorm); CHKERRQ(ierr); /* set parameter for default relative tolerance convergence test */ snes->ttol = fnorm*snes->rtol; /* test convergence */ ierr = (*snes->ops->converged)(snes,0,0.0,0.0,fnorm,&snes->reason,snes->cnvP); CHKERRQ(ierr); if (snes->reason) PetscFunctionReturn(0); /* Call general purpose update function */ if (snes->ops->update) { ierr = (*snes->ops->update)(snes, snes->iter); CHKERRQ(ierr); } /* first update -- just use the (preconditioned) residual direction for the initial conjugate direction */ if (snes->pc && snes->pcside == PC_RIGHT) { ierr = VecCopy(X, dX); CHKERRQ(ierr); ierr = SNESSetInitialFunction(snes->pc, F); CHKERRQ(ierr); ierr = SNESSetInitialFunctionNorm(snes->pc, fnorm); CHKERRQ(ierr); ierr = SNESSolve(snes->pc, B, dX); CHKERRQ(ierr); ierr = SNESGetConvergedReason(snes->pc,&reason); CHKERRQ(ierr); if (reason < 0 && (reason != SNES_DIVERGED_MAX_IT)) { snes->reason = SNES_DIVERGED_INNER; PetscFunctionReturn(0); } ierr = VecAYPX(dX,-1.0,X); CHKERRQ(ierr); } else { ierr = VecCopy(F, dX); CHKERRQ(ierr); } ierr = VecCopy(dX, lX); CHKERRQ(ierr); ierr = VecDot(F, dX, &dXdotF); CHKERRQ(ierr); /* } else { ierr = SNESNCGComputeYtJtF_Private(snes, X, F, dX, W, G, &dXdotF);CHKERRQ(ierr); } */ for (i = 1; i < maxits + 1; i++) { lsSuccess = PETSC_TRUE; /* some update types require the old update direction or conjugate direction */ if (ncg->type != SNES_NCG_FR) { ierr = VecCopy(F, Fold); CHKERRQ(ierr); } ierr = SNESLineSearchApply(linesearch, X, F, &fnorm, lX); CHKERRQ(ierr); ierr = SNESLineSearchGetSuccess(linesearch, &lsSuccess); CHKERRQ(ierr); if (!lsSuccess) { if (++snes->numFailures >= snes->maxFailures) { snes->reason = SNES_DIVERGED_LINE_SEARCH; PetscFunctionReturn(0); } } if (snes->nfuncs >= snes->max_funcs) { snes->reason = SNES_DIVERGED_FUNCTION_COUNT; PetscFunctionReturn(0); } if (snes->domainerror) { snes->reason = SNES_DIVERGED_FUNCTION_DOMAIN; PetscFunctionReturn(0); } ierr = SNESLineSearchGetNorms(linesearch, &xnorm, &fnorm, &ynorm); CHKERRQ(ierr); /* Monitor convergence */ ierr = PetscObjectTakeAccess(snes); CHKERRQ(ierr); snes->iter = i; snes->norm = fnorm; ierr = PetscObjectGrantAccess(snes); CHKERRQ(ierr); SNESLogConvHistory(snes,snes->norm,0); ierr = SNESMonitor(snes,snes->iter,snes->norm); CHKERRQ(ierr); /* Test for convergence */ ierr = (*snes->ops->converged)(snes,snes->iter,xnorm,ynorm,fnorm,&snes->reason,snes->cnvP); CHKERRQ(ierr); if (snes->reason) PetscFunctionReturn(0); /* Call general purpose update function */ if (snes->ops->update) { ierr = (*snes->ops->update)(snes, snes->iter); CHKERRQ(ierr); } if (snes->pc && snes->pcside == PC_RIGHT) { ierr = VecCopy(X,dX); CHKERRQ(ierr); ierr = SNESSetInitialFunction(snes->pc, F); CHKERRQ(ierr); ierr = SNESSetInitialFunctionNorm(snes->pc, fnorm); CHKERRQ(ierr); ierr = SNESSolve(snes->pc, B, dX); CHKERRQ(ierr); ierr = SNESGetConvergedReason(snes->pc,&reason); CHKERRQ(ierr); if (reason < 0 && (reason != SNES_DIVERGED_MAX_IT)) { snes->reason = SNES_DIVERGED_INNER; PetscFunctionReturn(0); } ierr = VecAYPX(dX,-1.0,X); CHKERRQ(ierr); } else { ierr = VecCopy(F, dX); CHKERRQ(ierr); } /* compute the conjugate direction lX = dX + beta*lX with beta = ((dX, dX) / (dX_old, dX_old) (Fletcher-Reeves update)*/ switch(ncg->type) { case SNES_NCG_FR: /* Fletcher-Reeves */ dXolddotFold = dXdotF; ierr = VecDot(dX, dX, &dXdotF); CHKERRQ(ierr); beta = PetscRealPart(dXdotF / dXolddotFold); break; case SNES_NCG_PRP: /* Polak-Ribiere-Poylak */ dXolddotFold = dXdotF; ierr = VecDotBegin(F, dX, &dXdotF); CHKERRQ(ierr); ierr = VecDotBegin(Fold, dX, &dXdotFold); CHKERRQ(ierr); ierr = VecDotEnd(F, dX, &dXdotF); CHKERRQ(ierr); ierr = VecDotEnd(Fold, dX, &dXdotFold); CHKERRQ(ierr); beta = PetscRealPart(((dXdotF - dXdotFold) / dXolddotFold)); if (beta < 0.0) beta = 0.0; /* restart */ break; case SNES_NCG_HS: /* Hestenes-Stiefel */ ierr = VecDotBegin(dX, F, &dXdotF); CHKERRQ(ierr); ierr = VecDotBegin(dX, Fold, &dXdotFold); CHKERRQ(ierr); ierr = VecDotBegin(lX, F, &lXdotF); CHKERRQ(ierr); ierr = VecDotBegin(lX, Fold, &lXdotFold); CHKERRQ(ierr); ierr = VecDotEnd(dX, F, &dXdotF); CHKERRQ(ierr); ierr = VecDotEnd(dX, Fold, &dXdotFold); CHKERRQ(ierr); ierr = VecDotEnd(lX, F, &lXdotF); CHKERRQ(ierr); ierr = VecDotEnd(lX, Fold, &lXdotFold); CHKERRQ(ierr); beta = PetscRealPart((dXdotF - dXdotFold) / (lXdotF - lXdotFold)); break; case SNES_NCG_DY: /* Dai-Yuan */ ierr = VecDotBegin(dX, F, &dXdotF); CHKERRQ(ierr); ierr = VecDotBegin(lX, F, &lXdotF); CHKERRQ(ierr); ierr = VecDotBegin(lX, Fold, &lXdotFold); CHKERRQ(ierr); ierr = VecDotEnd(dX, F, &dXdotF); CHKERRQ(ierr); ierr = VecDotEnd(lX, F, &lXdotF); CHKERRQ(ierr); ierr = VecDotEnd(lX, Fold, &lXdotFold); CHKERRQ(ierr); beta = PetscRealPart(dXdotF / (lXdotFold - lXdotF)); CHKERRQ(ierr); break; case SNES_NCG_CD: /* Conjugate Descent */ ierr = VecDotBegin(dX, F, &dXdotF); CHKERRQ(ierr); ierr = VecDotBegin(lX, Fold, &lXdotFold); CHKERRQ(ierr); ierr = VecDotEnd(dX, F, &dXdotF); CHKERRQ(ierr); ierr = VecDotEnd(lX, Fold, &lXdotFold); CHKERRQ(ierr); beta = PetscRealPart(dXdotF / lXdotFold); CHKERRQ(ierr); break; } if (ncg->monitor) { ierr = PetscViewerASCIIPrintf(ncg->monitor, "beta = %e\n", beta); CHKERRQ(ierr); } ierr = VecAYPX(lX, beta, dX); CHKERRQ(ierr); } ierr = PetscInfo1(snes, "Maximum number of iterations has been reached: %D\n", maxits); CHKERRQ(ierr); if (!snes->reason) snes->reason = SNES_DIVERGED_MAX_IT; PetscFunctionReturn(0); }
PetscErrorCode SNESSolve_NEWTONLS(SNES snes) { PetscErrorCode ierr; PetscInt maxits,i,lits; PetscBool lssucceed; MatStructure flg = DIFFERENT_NONZERO_PATTERN; PetscReal fnorm,gnorm,xnorm,ynorm; Vec Y,X,F,G,W,FPC; KSPConvergedReason kspreason; PetscBool domainerror; SNESLineSearch linesearch; SNESConvergedReason reason; PetscFunctionBegin; snes->numFailures = 0; snes->numLinearSolveFailures = 0; snes->reason = SNES_CONVERGED_ITERATING; maxits = snes->max_its; /* maximum number of iterations */ X = snes->vec_sol; /* solution vector */ F = snes->vec_func; /* residual vector */ Y = snes->vec_sol_update; /* newton step */ G = snes->work[0]; W = snes->work[1]; ierr = PetscObjectTakeAccess(snes);CHKERRQ(ierr); snes->iter = 0; snes->norm = 0.0; ierr = PetscObjectGrantAccess(snes);CHKERRQ(ierr); ierr = SNESGetSNESLineSearch(snes, &linesearch);CHKERRQ(ierr); if (!snes->vec_func_init_set) { ierr = SNESComputeFunction(snes,X,F);CHKERRQ(ierr); ierr = SNESGetFunctionDomainError(snes, &domainerror);CHKERRQ(ierr); if (domainerror) { snes->reason = SNES_DIVERGED_FUNCTION_DOMAIN; PetscFunctionReturn(0); } } else { snes->vec_func_init_set = PETSC_FALSE; } if (!snes->norm_init_set) { ierr = VecNormBegin(F,NORM_2,&fnorm);CHKERRQ(ierr); /* fnorm <- ||F|| */ ierr = VecNormEnd(F,NORM_2,&fnorm);CHKERRQ(ierr); if (PetscIsInfOrNanReal(fnorm)) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_FP,"User provided compute function generated a Not-a-Number"); } else { fnorm = snes->norm_init; snes->norm_init_set = PETSC_FALSE; } ierr = PetscObjectTakeAccess(snes);CHKERRQ(ierr); snes->norm = fnorm; ierr = PetscObjectGrantAccess(snes);CHKERRQ(ierr); SNESLogConvHistory(snes,fnorm,0); ierr = SNESMonitor(snes,0,fnorm);CHKERRQ(ierr); /* set parameter for default relative tolerance convergence test */ snes->ttol = fnorm*snes->rtol; /* test convergence */ ierr = (*snes->ops->converged)(snes,0,0.0,0.0,fnorm,&snes->reason,snes->cnvP);CHKERRQ(ierr); if (snes->reason) PetscFunctionReturn(0); for (i=0; i<maxits; i++) { /* Call general purpose update function */ if (snes->ops->update) { ierr = (*snes->ops->update)(snes, snes->iter);CHKERRQ(ierr); } /* apply the nonlinear preconditioner if it's right preconditioned */ if (snes->pc && snes->pcside == PC_RIGHT) { ierr = SNESSetInitialFunction(snes->pc, F);CHKERRQ(ierr); ierr = SNESSetInitialFunctionNorm(snes->pc, fnorm);CHKERRQ(ierr); ierr = SNESSolve(snes->pc, snes->vec_rhs, X);CHKERRQ(ierr); ierr = SNESGetConvergedReason(snes->pc,&reason);CHKERRQ(ierr); if (reason < 0 && reason != SNES_DIVERGED_MAX_IT) { snes->reason = SNES_DIVERGED_INNER; PetscFunctionReturn(0); } ierr = SNESGetFunction(snes->pc, &FPC, PETSC_NULL, PETSC_NULL);CHKERRQ(ierr); ierr = VecCopy(FPC, F);CHKERRQ(ierr); ierr = SNESGetFunctionNorm(snes->pc, &fnorm);CHKERRQ(ierr); } /* Solve J Y = F, where J is Jacobian matrix */ ierr = SNESComputeJacobian(snes,X,&snes->jacobian,&snes->jacobian_pre,&flg);CHKERRQ(ierr); ierr = KSPSetOperators(snes->ksp,snes->jacobian,snes->jacobian_pre,flg);CHKERRQ(ierr); ierr = SNES_KSPSolve(snes,snes->ksp,F,Y);CHKERRQ(ierr); ierr = KSPGetConvergedReason(snes->ksp,&kspreason);CHKERRQ(ierr); if (kspreason < 0) { if (++snes->numLinearSolveFailures >= snes->maxLinearSolveFailures) { ierr = PetscInfo2(snes,"iter=%D, number linear solve failures %D greater than current SNES allowed, stopping solve\n",snes->iter,snes->numLinearSolveFailures);CHKERRQ(ierr); snes->reason = SNES_DIVERGED_LINEAR_SOLVE; break; } } ierr = KSPGetIterationNumber(snes->ksp,&lits);CHKERRQ(ierr); snes->linear_its += lits; ierr = PetscInfo2(snes,"iter=%D, linear solve iterations=%D\n",snes->iter,lits);CHKERRQ(ierr); if (PetscLogPrintInfo){ ierr = SNESNEWTONLSCheckResidual_Private(snes,snes->jacobian,F,Y,G,W);CHKERRQ(ierr); } /* Compute a (scaled) negative update in the line search routine: X <- X - lambda*Y and evaluate F = function(X) (depends on the line search). */ gnorm = fnorm; ierr = SNESLineSearchApply(linesearch, X, F, &fnorm, Y);CHKERRQ(ierr); ierr = SNESLineSearchGetSuccess(linesearch, &lssucceed);CHKERRQ(ierr); ierr = SNESLineSearchGetNorms(linesearch, &xnorm, &fnorm, &ynorm);CHKERRQ(ierr); ierr = PetscInfo4(snes,"fnorm=%18.16e, gnorm=%18.16e, ynorm=%18.16e, lssucceed=%d\n",(double)gnorm,(double)fnorm,(double)ynorm,(int)lssucceed);CHKERRQ(ierr); if (snes->reason == SNES_DIVERGED_FUNCTION_COUNT) break; ierr = SNESGetFunctionDomainError(snes, &domainerror);CHKERRQ(ierr); if (domainerror) { snes->reason = SNES_DIVERGED_FUNCTION_DOMAIN; PetscFunctionReturn(0); } if (!lssucceed) { if (snes->stol*xnorm > ynorm) { snes->reason = SNES_CONVERGED_SNORM_RELATIVE; PetscFunctionReturn(0); } if (++snes->numFailures >= snes->maxFailures) { PetscBool ismin; snes->reason = SNES_DIVERGED_LINE_SEARCH; ierr = SNESNEWTONLSCheckLocalMin_Private(snes,snes->jacobian,F,W,fnorm,&ismin);CHKERRQ(ierr); if (ismin) snes->reason = SNES_DIVERGED_LOCAL_MIN; break; } } /* Monitor convergence */ ierr = PetscObjectTakeAccess(snes);CHKERRQ(ierr); snes->iter = i+1; snes->norm = fnorm; ierr = PetscObjectGrantAccess(snes);CHKERRQ(ierr); SNESLogConvHistory(snes,snes->norm,lits); ierr = SNESMonitor(snes,snes->iter,snes->norm);CHKERRQ(ierr); /* Test for convergence */ ierr = (*snes->ops->converged)(snes,snes->iter,xnorm,ynorm,fnorm,&snes->reason,snes->cnvP);CHKERRQ(ierr); if (snes->reason) break; } if (i == maxits) { ierr = PetscInfo1(snes,"Maximum number of iterations has been reached: %D\n",maxits);CHKERRQ(ierr); if (!snes->reason) snes->reason = SNES_DIVERGED_MAX_IT; } PetscFunctionReturn(0); }
PetscErrorCode SNESSolve_VINEWTONRSLS(SNES snes) { SNES_VINEWTONRSLS *vi = (SNES_VINEWTONRSLS*)snes->data; PetscErrorCode ierr; PetscInt maxits,i,lits; PetscBool lssucceed; MatStructure flg = DIFFERENT_NONZERO_PATTERN; PetscReal fnorm,gnorm,xnorm=0,ynorm; Vec Y,X,F; KSPConvergedReason kspreason; PetscFunctionBegin; snes->numFailures = 0; snes->numLinearSolveFailures = 0; snes->reason = SNES_CONVERGED_ITERATING; maxits = snes->max_its; /* maximum number of iterations */ X = snes->vec_sol; /* solution vector */ F = snes->vec_func; /* residual vector */ Y = snes->work[0]; /* work vectors */ ierr = SNESLineSearchSetVIFunctions(snes->linesearch, SNESVIProjectOntoBounds, SNESVIComputeInactiveSetFnorm);CHKERRQ(ierr); ierr = SNESLineSearchSetVecs(snes->linesearch, X, PETSC_NULL, PETSC_NULL, PETSC_NULL, PETSC_NULL);CHKERRQ(ierr); ierr = SNESLineSearchSetUp(snes->linesearch);CHKERRQ(ierr); ierr = PetscObjectTakeAccess(snes);CHKERRQ(ierr); snes->iter = 0; snes->norm = 0.0; ierr = PetscObjectGrantAccess(snes);CHKERRQ(ierr); ierr = SNESVIProjectOntoBounds(snes,X);CHKERRQ(ierr); ierr = SNESComputeFunction(snes,X,F);CHKERRQ(ierr); if (snes->domainerror) { snes->reason = SNES_DIVERGED_FUNCTION_DOMAIN; PetscFunctionReturn(0); } ierr = SNESVIComputeInactiveSetFnorm(snes,F,X,&fnorm);CHKERRQ(ierr); ierr = VecNormBegin(X,NORM_2,&xnorm);CHKERRQ(ierr); /* xnorm <- ||x|| */ ierr = VecNormEnd(X,NORM_2,&xnorm);CHKERRQ(ierr); if (PetscIsInfOrNanReal(fnorm)) SETERRQ(((PetscObject)X)->comm,PETSC_ERR_FP,"User provided compute function generated a Not-a-Number"); ierr = PetscObjectTakeAccess(snes);CHKERRQ(ierr); snes->norm = fnorm; ierr = PetscObjectGrantAccess(snes);CHKERRQ(ierr); SNESLogConvHistory(snes,fnorm,0); ierr = SNESMonitor(snes,0,fnorm);CHKERRQ(ierr); /* set parameter for default relative tolerance convergence test */ snes->ttol = fnorm*snes->rtol; /* test convergence */ ierr = (*snes->ops->converged)(snes,0,0.0,0.0,fnorm,&snes->reason,snes->cnvP);CHKERRQ(ierr); if (snes->reason) PetscFunctionReturn(0); for (i=0; i<maxits; i++) { IS IS_act,IS_inact; /* _act -> active set _inact -> inactive set */ IS IS_redact; /* redundant active set */ VecScatter scat_act,scat_inact; PetscInt nis_act,nis_inact; Vec Y_act,Y_inact,F_inact; Mat jac_inact_inact,prejac_inact_inact; PetscBool isequal; /* Call general purpose update function */ if (snes->ops->update) { ierr = (*snes->ops->update)(snes, snes->iter);CHKERRQ(ierr); } ierr = SNESComputeJacobian(snes,X,&snes->jacobian,&snes->jacobian_pre,&flg);CHKERRQ(ierr); /* Create active and inactive index sets */ /*original ierr = SNESVICreateIndexSets_RS(snes,X,F,&IS_act,&IS_inact);CHKERRQ(ierr); */ ierr = SNESVIGetActiveSetIS(snes,X,F,&IS_act);CHKERRQ(ierr); if (vi->checkredundancy) { (*vi->checkredundancy)(snes,IS_act,&IS_redact,vi->ctxP);CHKERRQ(ierr); if (IS_redact){ ierr = ISSort(IS_redact);CHKERRQ(ierr); ierr = ISComplement(IS_redact,X->map->rstart,X->map->rend,&IS_inact);CHKERRQ(ierr); ierr = ISDestroy(&IS_redact);CHKERRQ(ierr); } else { ierr = ISComplement(IS_act,X->map->rstart,X->map->rend,&IS_inact);CHKERRQ(ierr); } } else { ierr = ISComplement(IS_act,X->map->rstart,X->map->rend,&IS_inact);CHKERRQ(ierr); } /* Create inactive set submatrix */ ierr = MatGetSubMatrix(snes->jacobian,IS_inact,IS_inact,MAT_INITIAL_MATRIX,&jac_inact_inact);CHKERRQ(ierr); if (0) { /* Dead code (temporary developer hack) */ IS keptrows; ierr = MatFindNonzeroRows(jac_inact_inact,&keptrows);CHKERRQ(ierr); if (keptrows) { PetscInt cnt,*nrows,k; const PetscInt *krows,*inact; PetscInt rstart=jac_inact_inact->rmap->rstart; ierr = MatDestroy(&jac_inact_inact);CHKERRQ(ierr); ierr = ISDestroy(&IS_act);CHKERRQ(ierr); ierr = ISGetLocalSize(keptrows,&cnt);CHKERRQ(ierr); ierr = ISGetIndices(keptrows,&krows);CHKERRQ(ierr); ierr = ISGetIndices(IS_inact,&inact);CHKERRQ(ierr); ierr = PetscMalloc(cnt*sizeof(PetscInt),&nrows);CHKERRQ(ierr); for (k=0; k<cnt; k++) { nrows[k] = inact[krows[k]-rstart]; } ierr = ISRestoreIndices(keptrows,&krows);CHKERRQ(ierr); ierr = ISRestoreIndices(IS_inact,&inact);CHKERRQ(ierr); ierr = ISDestroy(&keptrows);CHKERRQ(ierr); ierr = ISDestroy(&IS_inact);CHKERRQ(ierr); ierr = ISCreateGeneral(((PetscObject)snes)->comm,cnt,nrows,PETSC_OWN_POINTER,&IS_inact);CHKERRQ(ierr); ierr = ISComplement(IS_inact,F->map->rstart,F->map->rend,&IS_act);CHKERRQ(ierr); ierr = MatGetSubMatrix(snes->jacobian,IS_inact,IS_inact,MAT_INITIAL_MATRIX,&jac_inact_inact);CHKERRQ(ierr); } } ierr = DMSetVI(snes->dm,IS_inact);CHKERRQ(ierr); /* remove later */ /* ierr = VecView(vi->xu,PETSC_VIEWER_BINARY_(((PetscObject)(vi->xu))->comm));CHKERRQ(ierr); ierr = VecView(vi->xl,PETSC_VIEWER_BINARY_(((PetscObject)(vi->xl))->comm));CHKERRQ(ierr); ierr = VecView(X,PETSC_VIEWER_BINARY_(((PetscObject)X)->comm));CHKERRQ(ierr); ierr = VecView(F,PETSC_VIEWER_BINARY_(((PetscObject)F)->comm));CHKERRQ(ierr); ierr = ISView(IS_inact,PETSC_VIEWER_BINARY_(((PetscObject)IS_inact)->comm));CHKERRQ(ierr); */ /* Get sizes of active and inactive sets */ ierr = ISGetLocalSize(IS_act,&nis_act);CHKERRQ(ierr); ierr = ISGetLocalSize(IS_inact,&nis_inact);CHKERRQ(ierr); /* Create active and inactive set vectors */ ierr = SNESCreateSubVectors_VINEWTONRSLS(snes,nis_inact,&F_inact);CHKERRQ(ierr); ierr = SNESCreateSubVectors_VINEWTONRSLS(snes,nis_act,&Y_act);CHKERRQ(ierr); ierr = SNESCreateSubVectors_VINEWTONRSLS(snes,nis_inact,&Y_inact);CHKERRQ(ierr); /* Create scatter contexts */ ierr = VecScatterCreate(Y,IS_act,Y_act,PETSC_NULL,&scat_act);CHKERRQ(ierr); ierr = VecScatterCreate(Y,IS_inact,Y_inact,PETSC_NULL,&scat_inact);CHKERRQ(ierr); /* Do a vec scatter to active and inactive set vectors */ ierr = VecScatterBegin(scat_inact,F,F_inact,INSERT_VALUES,SCATTER_FORWARD);CHKERRQ(ierr); ierr = VecScatterEnd(scat_inact,F,F_inact,INSERT_VALUES,SCATTER_FORWARD);CHKERRQ(ierr); ierr = VecScatterBegin(scat_act,Y,Y_act,INSERT_VALUES,SCATTER_FORWARD);CHKERRQ(ierr); ierr = VecScatterEnd(scat_act,Y,Y_act,INSERT_VALUES,SCATTER_FORWARD);CHKERRQ(ierr); ierr = VecScatterBegin(scat_inact,Y,Y_inact,INSERT_VALUES,SCATTER_FORWARD);CHKERRQ(ierr); ierr = VecScatterEnd(scat_inact,Y,Y_inact,INSERT_VALUES,SCATTER_FORWARD);CHKERRQ(ierr); /* Active set direction = 0 */ ierr = VecSet(Y_act,0);CHKERRQ(ierr); if (snes->jacobian != snes->jacobian_pre) { ierr = MatGetSubMatrix(snes->jacobian_pre,IS_inact,IS_inact,MAT_INITIAL_MATRIX,&prejac_inact_inact);CHKERRQ(ierr); } else prejac_inact_inact = jac_inact_inact; ierr = ISEqual(vi->IS_inact_prev,IS_inact,&isequal);CHKERRQ(ierr); if (!isequal) { ierr = SNESVIResetPCandKSP(snes,jac_inact_inact,prejac_inact_inact);CHKERRQ(ierr); flg = DIFFERENT_NONZERO_PATTERN; } /* ierr = ISView(IS_inact,0);CHKERRQ(ierr); */ /* ierr = ISView(IS_act,0);CHKERRQ(ierr);*/ /* ierr = MatView(snes->jacobian_pre,0); */ ierr = KSPSetOperators(snes->ksp,jac_inact_inact,prejac_inact_inact,flg);CHKERRQ(ierr); ierr = KSPSetUp(snes->ksp);CHKERRQ(ierr); { PC pc; PetscBool flg; ierr = KSPGetPC(snes->ksp,&pc);CHKERRQ(ierr); ierr = PetscObjectTypeCompare((PetscObject)pc,PCFIELDSPLIT,&flg);CHKERRQ(ierr); if (flg) { KSP *subksps; ierr = PCFieldSplitGetSubKSP(pc,PETSC_NULL,&subksps);CHKERRQ(ierr); ierr = KSPGetPC(subksps[0],&pc);CHKERRQ(ierr); ierr = PetscFree(subksps);CHKERRQ(ierr); ierr = PetscObjectTypeCompare((PetscObject)pc,PCBJACOBI,&flg);CHKERRQ(ierr); if (flg) { PetscInt n,N = 101*101,j,cnts[3] = {0,0,0}; const PetscInt *ii; ierr = ISGetSize(IS_inact,&n);CHKERRQ(ierr); ierr = ISGetIndices(IS_inact,&ii);CHKERRQ(ierr); for (j=0; j<n; j++) { if (ii[j] < N) cnts[0]++; else if (ii[j] < 2*N) cnts[1]++; else if (ii[j] < 3*N) cnts[2]++; } ierr = ISRestoreIndices(IS_inact,&ii);CHKERRQ(ierr); ierr = PCBJacobiSetTotalBlocks(pc,3,cnts);CHKERRQ(ierr); } } } ierr = SNES_KSPSolve(snes,snes->ksp,F_inact,Y_inact);CHKERRQ(ierr); ierr = KSPGetConvergedReason(snes->ksp,&kspreason);CHKERRQ(ierr); if (kspreason < 0) { if (++snes->numLinearSolveFailures >= snes->maxLinearSolveFailures) { ierr = PetscInfo2(snes,"iter=%D, number linear solve failures %D greater than current SNES allowed, stopping solve\n",snes->iter,snes->numLinearSolveFailures);CHKERRQ(ierr); snes->reason = SNES_DIVERGED_LINEAR_SOLVE; break; } } ierr = VecScatterBegin(scat_act,Y_act,Y,INSERT_VALUES,SCATTER_REVERSE);CHKERRQ(ierr); ierr = VecScatterEnd(scat_act,Y_act,Y,INSERT_VALUES,SCATTER_REVERSE);CHKERRQ(ierr); ierr = VecScatterBegin(scat_inact,Y_inact,Y,INSERT_VALUES,SCATTER_REVERSE);CHKERRQ(ierr); ierr = VecScatterEnd(scat_inact,Y_inact,Y,INSERT_VALUES,SCATTER_REVERSE);CHKERRQ(ierr); ierr = VecDestroy(&F_inact);CHKERRQ(ierr); ierr = VecDestroy(&Y_act);CHKERRQ(ierr); ierr = VecDestroy(&Y_inact);CHKERRQ(ierr); ierr = VecScatterDestroy(&scat_act);CHKERRQ(ierr); ierr = VecScatterDestroy(&scat_inact);CHKERRQ(ierr); ierr = ISDestroy(&IS_act);CHKERRQ(ierr); if (!isequal) { ierr = ISDestroy(&vi->IS_inact_prev);CHKERRQ(ierr); ierr = ISDuplicate(IS_inact,&vi->IS_inact_prev);CHKERRQ(ierr); } ierr = ISDestroy(&IS_inact);CHKERRQ(ierr); ierr = MatDestroy(&jac_inact_inact);CHKERRQ(ierr); if (snes->jacobian != snes->jacobian_pre) { ierr = MatDestroy(&prejac_inact_inact);CHKERRQ(ierr); } ierr = KSPGetIterationNumber(snes->ksp,&lits);CHKERRQ(ierr); snes->linear_its += lits; ierr = PetscInfo2(snes,"iter=%D, linear solve iterations=%D\n",snes->iter,lits);CHKERRQ(ierr); /* if (snes->ops->precheck) { PetscBool changed_y = PETSC_FALSE; ierr = (*snes->ops->precheck)(snes,X,Y,snes->precheck,&changed_y);CHKERRQ(ierr); } if (PetscLogPrintInfo){ ierr = SNESVICheckResidual_Private(snes,snes->jacobian,F,Y,G,W);CHKERRQ(ierr); } */ /* Compute a (scaled) negative update in the line search routine: Y <- X - lambda*Y and evaluate G = function(Y) (depends on the line search). */ ierr = VecCopy(Y,snes->vec_sol_update);CHKERRQ(ierr); ynorm = 1; gnorm = fnorm; ierr = SNESLineSearchApply(snes->linesearch, X, F, &gnorm, Y);CHKERRQ(ierr); ierr = SNESLineSearchGetNorms(snes->linesearch, &xnorm, &gnorm, &ynorm);CHKERRQ(ierr); ierr = PetscInfo4(snes,"fnorm=%18.16e, gnorm=%18.16e, ynorm=%18.16e, lssucceed=%d\n",(double)fnorm,(double)gnorm,(double)ynorm,(int)lssucceed);CHKERRQ(ierr); if (snes->reason == SNES_DIVERGED_FUNCTION_COUNT) break; if (snes->domainerror) { snes->reason = SNES_DIVERGED_FUNCTION_DOMAIN; ierr = DMDestroyVI(snes->dm);CHKERRQ(ierr); PetscFunctionReturn(0); } ierr = SNESLineSearchGetSuccess(snes->linesearch, &lssucceed);CHKERRQ(ierr); if (!lssucceed) { if (++snes->numFailures >= snes->maxFailures) { PetscBool ismin; snes->reason = SNES_DIVERGED_LINE_SEARCH; ierr = SNESVICheckLocalMin_Private(snes,snes->jacobian,F,X,gnorm,&ismin);CHKERRQ(ierr); if (ismin) snes->reason = SNES_DIVERGED_LOCAL_MIN; break; } } /* Update function and solution vectors */ fnorm = gnorm; /* Monitor convergence */ ierr = PetscObjectTakeAccess(snes);CHKERRQ(ierr); snes->iter = i+1; snes->norm = fnorm; ierr = PetscObjectGrantAccess(snes);CHKERRQ(ierr); SNESLogConvHistory(snes,snes->norm,lits); ierr = SNESMonitor(snes,snes->iter,snes->norm);CHKERRQ(ierr); /* Test for convergence, xnorm = || X || */ if (snes->ops->converged != SNESSkipConverged) { ierr = VecNorm(X,NORM_2,&xnorm);CHKERRQ(ierr); } ierr = (*snes->ops->converged)(snes,snes->iter,xnorm,ynorm,fnorm,&snes->reason,snes->cnvP);CHKERRQ(ierr); if (snes->reason) break; } ierr = DMDestroyVI(snes->dm);CHKERRQ(ierr); if (i == maxits) { ierr = PetscInfo1(snes,"Maximum number of iterations has been reached: %D\n",maxits);CHKERRQ(ierr); if (!snes->reason) snes->reason = SNES_DIVERGED_MAX_IT; } PetscFunctionReturn(0); }
static PetscErrorCode SNESSolve_TR(SNES snes) { SNES_TR *neP = (SNES_TR*)snes->data; Vec X,F,Y,G,Ytmp; PetscErrorCode ierr; PetscInt maxits,i,lits; MatStructure flg = DIFFERENT_NONZERO_PATTERN; PetscReal rho,fnorm,gnorm,gpnorm,xnorm=0,delta,nrm,ynorm,norm1; PetscScalar cnorm; KSP ksp; SNESConvergedReason reason = SNES_CONVERGED_ITERATING; PetscBool conv = PETSC_FALSE,breakout = PETSC_FALSE; PetscBool domainerror; PetscFunctionBegin; maxits = snes->max_its; /* maximum number of iterations */ X = snes->vec_sol; /* solution vector */ F = snes->vec_func; /* residual vector */ Y = snes->work[0]; /* work vectors */ G = snes->work[1]; Ytmp = snes->work[2]; ierr = PetscObjectTakeAccess(snes);CHKERRQ(ierr); snes->iter = 0; ierr = PetscObjectGrantAccess(snes);CHKERRQ(ierr); if (!snes->vec_func_init_set) { ierr = SNESComputeFunction(snes,X,F);CHKERRQ(ierr); /* F(X) */ ierr = SNESGetFunctionDomainError(snes, &domainerror);CHKERRQ(ierr); if (domainerror) { snes->reason = SNES_DIVERGED_FUNCTION_DOMAIN; PetscFunctionReturn(0); } } else { snes->vec_func_init_set = PETSC_FALSE; } if (!snes->norm_init_set) { ierr = VecNorm(F,NORM_2,&fnorm);CHKERRQ(ierr); /* fnorm <- || F || */ if (PetscIsInfOrNanReal(fnorm)) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_FP,"User provided compute function generated a Not-a-Number"); } else { fnorm = snes->norm_init; snes->norm_init_set = PETSC_FALSE; } ierr = PetscObjectTakeAccess(snes);CHKERRQ(ierr); snes->norm = fnorm; ierr = PetscObjectGrantAccess(snes);CHKERRQ(ierr); delta = neP->delta0*fnorm; neP->delta = delta; SNESLogConvHistory(snes,fnorm,0); ierr = SNESMonitor(snes,0,fnorm);CHKERRQ(ierr); /* set parameter for default relative tolerance convergence test */ snes->ttol = fnorm*snes->rtol; /* test convergence */ ierr = (*snes->ops->converged)(snes,snes->iter,0.0,0.0,fnorm,&snes->reason,snes->cnvP);CHKERRQ(ierr); if (snes->reason) PetscFunctionReturn(0); /* Set the stopping criteria to use the More' trick. */ ierr = PetscOptionsGetBool(PETSC_NULL,"-snes_tr_ksp_regular_convergence_test",&conv,PETSC_NULL);CHKERRQ(ierr); if (!conv) { SNES_TR_KSPConverged_Ctx *ctx; ierr = SNESGetKSP(snes,&ksp);CHKERRQ(ierr); ierr = PetscNew(SNES_TR_KSPConverged_Ctx,&ctx);CHKERRQ(ierr); ctx->snes = snes; ierr = KSPDefaultConvergedCreate(&ctx->ctx);CHKERRQ(ierr); ierr = KSPSetConvergenceTest(ksp,SNES_TR_KSPConverged_Private,ctx,SNES_TR_KSPConverged_Destroy);CHKERRQ(ierr); ierr = PetscInfo(snes,"Using Krylov convergence test SNES_TR_KSPConverged_Private\n");CHKERRQ(ierr); } for (i=0; i<maxits; i++) { /* Call general purpose update function */ if (snes->ops->update) { ierr = (*snes->ops->update)(snes, snes->iter);CHKERRQ(ierr); } /* Solve J Y = F, where J is Jacobian matrix */ ierr = SNESComputeJacobian(snes,X,&snes->jacobian,&snes->jacobian_pre,&flg);CHKERRQ(ierr); ierr = KSPSetOperators(snes->ksp,snes->jacobian,snes->jacobian_pre,flg);CHKERRQ(ierr); ierr = SNES_KSPSolve(snes,snes->ksp,F,Ytmp);CHKERRQ(ierr); ierr = KSPGetIterationNumber(snes->ksp,&lits);CHKERRQ(ierr); snes->linear_its += lits; ierr = PetscInfo2(snes,"iter=%D, linear solve iterations=%D\n",snes->iter,lits);CHKERRQ(ierr); ierr = VecNorm(Ytmp,NORM_2,&nrm);CHKERRQ(ierr); norm1 = nrm; while(1) { ierr = VecCopy(Ytmp,Y);CHKERRQ(ierr); nrm = norm1; /* Scale Y if need be and predict new value of F norm */ if (nrm >= delta) { nrm = delta/nrm; gpnorm = (1.0 - nrm)*fnorm; cnorm = nrm; ierr = PetscInfo1(snes,"Scaling direction by %G\n",nrm);CHKERRQ(ierr); ierr = VecScale(Y,cnorm);CHKERRQ(ierr); nrm = gpnorm; ynorm = delta; } else { gpnorm = 0.0; ierr = PetscInfo(snes,"Direction is in Trust Region\n");CHKERRQ(ierr); ynorm = nrm; } ierr = VecAYPX(Y,-1.0,X);CHKERRQ(ierr); /* Y <- X - Y */ ierr = VecCopy(X,snes->vec_sol_update);CHKERRQ(ierr); ierr = SNESComputeFunction(snes,Y,G);CHKERRQ(ierr); /* F(X) */ ierr = VecNorm(G,NORM_2,&gnorm);CHKERRQ(ierr); /* gnorm <- || g || */ if (fnorm == gpnorm) rho = 0.0; else rho = (fnorm*fnorm - gnorm*gnorm)/(fnorm*fnorm - gpnorm*gpnorm); /* Update size of trust region */ if (rho < neP->mu) delta *= neP->delta1; else if (rho < neP->eta) delta *= neP->delta2; else delta *= neP->delta3; ierr = PetscInfo3(snes,"fnorm=%G, gnorm=%G, ynorm=%G\n",fnorm,gnorm,ynorm);CHKERRQ(ierr); ierr = PetscInfo3(snes,"gpred=%G, rho=%G, delta=%G\n",gpnorm,rho,delta);CHKERRQ(ierr); neP->delta = delta; if (rho > neP->sigma) break; ierr = PetscInfo(snes,"Trying again in smaller region\n");CHKERRQ(ierr); /* check to see if progress is hopeless */ neP->itflag = PETSC_FALSE; ierr = SNES_TR_Converged_Private(snes,snes->iter,xnorm,ynorm,fnorm,&reason,snes->cnvP);CHKERRQ(ierr); if (!reason) { ierr = (*snes->ops->converged)(snes,snes->iter,xnorm,ynorm,fnorm,&reason,snes->cnvP);CHKERRQ(ierr); } if (reason) { /* We're not progressing, so return with the current iterate */ ierr = SNESMonitor(snes,i+1,fnorm);CHKERRQ(ierr); breakout = PETSC_TRUE; break; } snes->numFailures++; } if (!breakout) { /* Update function and solution vectors */ fnorm = gnorm; ierr = VecCopy(G,F);CHKERRQ(ierr); ierr = VecCopy(Y,X);CHKERRQ(ierr); /* Monitor convergence */ ierr = PetscObjectTakeAccess(snes);CHKERRQ(ierr); snes->iter = i+1; snes->norm = fnorm; ierr = PetscObjectGrantAccess(snes);CHKERRQ(ierr); SNESLogConvHistory(snes,snes->norm,lits); ierr = SNESMonitor(snes,snes->iter,snes->norm);CHKERRQ(ierr); /* Test for convergence, xnorm = || X || */ neP->itflag = PETSC_TRUE; if (snes->ops->converged != SNESSkipConverged) { ierr = VecNorm(X,NORM_2,&xnorm);CHKERRQ(ierr); } ierr = (*snes->ops->converged)(snes,snes->iter,xnorm,ynorm,fnorm,&reason,snes->cnvP);CHKERRQ(ierr); if (reason) break; } else { break; } } if (i == maxits) { ierr = PetscInfo1(snes,"Maximum number of iterations has been reached: %D\n",maxits);CHKERRQ(ierr); if (!reason) reason = SNES_DIVERGED_MAX_IT; } ierr = PetscObjectTakeAccess(snes);CHKERRQ(ierr); snes->reason = reason; ierr = PetscObjectGrantAccess(snes);CHKERRQ(ierr); PetscFunctionReturn(0); }
PetscErrorCode SNESSolve_LS(SNES snes) { SNES_LS *neP = (SNES_LS*)snes->data; PetscErrorCode ierr; PetscInt maxits,i,lits; PetscTruth lssucceed; MatStructure flg = DIFFERENT_NONZERO_PATTERN; PetscReal fnorm,gnorm,xnorm=0,ynorm; Vec Y,X,F,G,W; KSPConvergedReason kspreason; PetscFunctionBegin; snes->numFailures = 0; snes->numLinearSolveFailures = 0; snes->reason = SNES_CONVERGED_ITERATING; maxits = snes->max_its; /* maximum number of iterations */ X = snes->vec_sol; /* solution vector */ F = snes->vec_func; /* residual vector */ Y = snes->work[0]; /* work vectors */ G = snes->work[1]; W = snes->work[2]; ierr = PetscObjectTakeAccess(snes);CHKERRQ(ierr); snes->iter = 0; snes->norm = 0.0; ierr = PetscObjectGrantAccess(snes);CHKERRQ(ierr); ierr = SNESComputeFunction(snes,X,F);CHKERRQ(ierr); if (snes->domainerror) { snes->reason = SNES_DIVERGED_FUNCTION_DOMAIN; PetscFunctionReturn(0); } ierr = VecNormBegin(F,NORM_2,&fnorm);CHKERRQ(ierr); /* fnorm <- ||F|| */ ierr = VecNormBegin(X,NORM_2,&xnorm);CHKERRQ(ierr); /* xnorm <- ||x|| */ ierr = VecNormEnd(F,NORM_2,&fnorm);CHKERRQ(ierr); ierr = VecNormEnd(X,NORM_2,&xnorm);CHKERRQ(ierr); if PetscIsInfOrNanReal(fnorm) SETERRQ(PETSC_ERR_FP,"User provided compute function generated a Not-a-Number"); ierr = PetscObjectTakeAccess(snes);CHKERRQ(ierr); snes->norm = fnorm; ierr = PetscObjectGrantAccess(snes);CHKERRQ(ierr); SNESLogConvHistory(snes,fnorm,0); SNESMonitor(snes,0,fnorm); /* set parameter for default relative tolerance convergence test */ snes->ttol = fnorm*snes->rtol; /* test convergence */ ierr = (*snes->ops->converged)(snes,0,0.0,0.0,fnorm,&snes->reason,snes->cnvP);CHKERRQ(ierr); if (snes->reason) PetscFunctionReturn(0); for (i=0; i<maxits; i++) { /* Call general purpose update function */ if (snes->ops->update) { ierr = (*snes->ops->update)(snes, snes->iter);CHKERRQ(ierr); } /* Solve J Y = F, where J is Jacobian matrix */ ierr = SNESComputeJacobian(snes,X,&snes->jacobian,&snes->jacobian_pre,&flg);CHKERRQ(ierr); ierr = KSPSetOperators(snes->ksp,snes->jacobian,snes->jacobian_pre,flg);CHKERRQ(ierr); ierr = SNES_KSPSolve(snes,snes->ksp,F,Y);CHKERRQ(ierr); ierr = KSPGetConvergedReason(snes->ksp,&kspreason);CHKERRQ(ierr); if (kspreason < 0) { if (++snes->numLinearSolveFailures >= snes->maxLinearSolveFailures) { ierr = PetscInfo2(snes,"iter=%D, number linear solve failures %D greater than current SNES allowed, stopping solve\n",snes->iter,snes->numLinearSolveFailures);CHKERRQ(ierr); snes->reason = SNES_DIVERGED_LINEAR_SOLVE; break; } } ierr = KSPGetIterationNumber(snes->ksp,&lits);CHKERRQ(ierr); snes->linear_its += lits; ierr = PetscInfo2(snes,"iter=%D, linear solve iterations=%D\n",snes->iter,lits);CHKERRQ(ierr); if (neP->precheckstep) { PetscTruth changed_y = PETSC_FALSE; ierr = (*neP->precheckstep)(snes,X,Y,neP->precheck,&changed_y);CHKERRQ(ierr); } if (PetscLogPrintInfo){ ierr = SNESLSCheckResidual_Private(snes,snes->jacobian,F,Y,G,W);CHKERRQ(ierr); } /* Compute a (scaled) negative update in the line search routine: Y <- X - lambda*Y and evaluate G = function(Y) (depends on the line search). */ ierr = VecCopy(Y,snes->vec_sol_update);CHKERRQ(ierr); ynorm = 1; gnorm = fnorm; ierr = (*neP->LineSearch)(snes,neP->lsP,X,F,G,Y,W,fnorm,xnorm,&ynorm,&gnorm,&lssucceed);CHKERRQ(ierr); ierr = PetscInfo4(snes,"fnorm=%18.16e, gnorm=%18.16e, ynorm=%18.16e, lssucceed=%d\n",fnorm,gnorm,ynorm,(int)lssucceed);CHKERRQ(ierr); if (snes->reason == SNES_DIVERGED_FUNCTION_COUNT) break; if (snes->domainerror) { snes->reason = SNES_DIVERGED_FUNCTION_DOMAIN; PetscFunctionReturn(0); } if (!lssucceed) { if (++snes->numFailures >= snes->maxFailures) { PetscTruth ismin; snes->reason = SNES_DIVERGED_LS_FAILURE; ierr = SNESLSCheckLocalMin_Private(snes,snes->jacobian,G,W,gnorm,&ismin);CHKERRQ(ierr); if (ismin) snes->reason = SNES_DIVERGED_LOCAL_MIN; break; } } /* Update function and solution vectors */ fnorm = gnorm; ierr = VecCopy(G,F);CHKERRQ(ierr); ierr = VecCopy(W,X);CHKERRQ(ierr); /* Monitor convergence */ ierr = PetscObjectTakeAccess(snes);CHKERRQ(ierr); snes->iter = i+1; snes->norm = fnorm; ierr = PetscObjectGrantAccess(snes);CHKERRQ(ierr); SNESLogConvHistory(snes,snes->norm,lits); SNESMonitor(snes,snes->iter,snes->norm); /* Test for convergence, xnorm = || X || */ if (snes->ops->converged != SNESSkipConverged) { ierr = VecNorm(X,NORM_2,&xnorm);CHKERRQ(ierr); } ierr = (*snes->ops->converged)(snes,snes->iter,xnorm,ynorm,fnorm,&snes->reason,snes->cnvP);CHKERRQ(ierr); if (snes->reason) break; } if (i == maxits) { ierr = PetscInfo1(snes,"Maximum number of iterations has been reached: %D\n",maxits);CHKERRQ(ierr); if(!snes->reason) snes->reason = SNES_DIVERGED_MAX_IT; } PetscFunctionReturn(0); }
static PetscErrorCode SNESSolve_QN(SNES snes) { PetscErrorCode ierr; SNES_QN *qn = (SNES_QN*) snes->data; Vec X,Xold; Vec F,B; Vec Y,FPC,D,Dold; SNESConvergedReason reason; PetscInt i, i_r; PetscReal fnorm,xnorm,ynorm,gnorm; PetscBool lssucceed,powell,periodic; PetscScalar DolddotD,DolddotDold,DdotD,YdotD; MatStructure flg = DIFFERENT_NONZERO_PATTERN; /* basically just a regular newton's method except for the application of the jacobian */ PetscFunctionBegin; F = snes->vec_func; /* residual vector */ Y = snes->vec_sol_update; /* search direction generated by J^-1D*/ B = snes->vec_rhs; X = snes->vec_sol; /* solution vector */ Xold = snes->work[0]; /* directions generated by the preconditioned problem with F_pre = F or x - M(x, b) */ D = snes->work[1]; Dold = snes->work[2]; snes->reason = SNES_CONVERGED_ITERATING; ierr = PetscObjectTakeAccess(snes);CHKERRQ(ierr); snes->iter = 0; snes->norm = 0.; ierr = PetscObjectGrantAccess(snes);CHKERRQ(ierr); if (!snes->vec_func_init_set){ ierr = SNESComputeFunction(snes,X,F);CHKERRQ(ierr); if (snes->domainerror) { snes->reason = SNES_DIVERGED_FUNCTION_DOMAIN; PetscFunctionReturn(0); } } else { snes->vec_func_init_set = PETSC_FALSE; } if (!snes->norm_init_set) { ierr = VecNorm(F, NORM_2, &fnorm);CHKERRQ(ierr); /* fnorm <- ||F|| */ if (PetscIsInfOrNanReal(fnorm)) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_FP,"Infinite or not-a-number generated in norm"); } else { fnorm = snes->norm_init; snes->norm_init_set = PETSC_FALSE; } ierr = PetscObjectTakeAccess(snes);CHKERRQ(ierr); snes->norm = fnorm; ierr = PetscObjectGrantAccess(snes);CHKERRQ(ierr); SNESLogConvHistory(snes,fnorm,0); ierr = SNESMonitor(snes,0,fnorm);CHKERRQ(ierr); /* set parameter for default relative tolerance convergence test */ snes->ttol = fnorm*snes->rtol; /* test convergence */ ierr = (*snes->ops->converged)(snes,0,0.0,0.0,fnorm,&snes->reason,snes->cnvP);CHKERRQ(ierr); if (snes->reason) PetscFunctionReturn(0); /* composed solve */ if (snes->pc && snes->pcside == PC_RIGHT) { ierr = SNESSetInitialFunction(snes->pc, F);CHKERRQ(ierr); ierr = SNESSetInitialFunctionNorm(snes->pc, fnorm);CHKERRQ(ierr); ierr = SNESSolve(snes->pc, B, X);CHKERRQ(ierr); ierr = SNESGetConvergedReason(snes->pc,&reason);CHKERRQ(ierr); if (reason < 0 && (reason != SNES_DIVERGED_MAX_IT)) { snes->reason = SNES_DIVERGED_INNER; PetscFunctionReturn(0); } ierr = SNESGetFunction(snes->pc, &FPC, PETSC_NULL, PETSC_NULL);CHKERRQ(ierr); ierr = VecCopy(FPC, F);CHKERRQ(ierr); ierr = SNESGetFunctionNorm(snes->pc, &fnorm);CHKERRQ(ierr); ierr = VecCopy(F, Y);CHKERRQ(ierr); } else { ierr = VecCopy(F, Y);CHKERRQ(ierr); } ierr = VecCopy(Y, D);CHKERRQ(ierr); /* scale the initial update */ if (qn->scale_type == SNES_QN_SCALE_JACOBIAN) { ierr = SNESComputeJacobian(snes,X,&snes->jacobian,&snes->jacobian_pre,&flg);CHKERRQ(ierr); } for (i = 0, i_r = 0; i < snes->max_its; i++, i_r++) { switch(qn->type) { case SNES_QN_BADBROYDEN: ierr = SNESQNApply_BadBroyden(snes,i_r,Y,X,Xold,D,Dold);CHKERRQ(ierr); break; case SNES_QN_BROYDEN: ierr = SNESQNApply_Broyden(snes,i_r,Y,X,Xold,D,Dold);CHKERRQ(ierr); break; case SNES_QN_LBFGS: SNESQNApply_LBFGS(snes,i_r,Y,X,Xold,D,Dold);CHKERRQ(ierr); break; } /* line search for lambda */ ynorm = 1; gnorm = fnorm; ierr = VecCopy(D, Dold);CHKERRQ(ierr); ierr = VecCopy(X, Xold);CHKERRQ(ierr); ierr = SNESLineSearchApply(snes->linesearch, X, F, &fnorm, Y);CHKERRQ(ierr); if (snes->reason == SNES_DIVERGED_FUNCTION_COUNT) break; if (snes->domainerror) { snes->reason = SNES_DIVERGED_FUNCTION_DOMAIN; PetscFunctionReturn(0); } ierr = SNESLineSearchGetSuccess(snes->linesearch, &lssucceed);CHKERRQ(ierr); if (!lssucceed) { if (++snes->numFailures >= snes->maxFailures) { snes->reason = SNES_DIVERGED_LINE_SEARCH; break; } } ierr = SNESLineSearchGetNorms(snes->linesearch, &xnorm, &fnorm, &ynorm);CHKERRQ(ierr); if (qn->scale_type == SNES_QN_SCALE_LINESEARCH) { ierr = SNESLineSearchGetLambda(snes->linesearch, &qn->scaling);CHKERRQ(ierr); } /* convergence monitoring */ ierr = PetscInfo4(snes,"fnorm=%18.16e, gnorm=%18.16e, ynorm=%18.16e, lssucceed=%d\n",(double)fnorm,(double)gnorm,(double)ynorm,(int)lssucceed);CHKERRQ(ierr); ierr = SNESSetIterationNumber(snes, i+1);CHKERRQ(ierr); ierr = SNESSetFunctionNorm(snes, fnorm);CHKERRQ(ierr); SNESLogConvHistory(snes,snes->norm,snes->iter); ierr = SNESMonitor(snes,snes->iter,snes->norm);CHKERRQ(ierr); /* set parameter for default relative tolerance convergence test */ ierr = (*snes->ops->converged)(snes,snes->iter,xnorm,ynorm,fnorm,&snes->reason,snes->cnvP);CHKERRQ(ierr); if (snes->reason) PetscFunctionReturn(0); if (snes->pc && snes->pcside == PC_RIGHT) { ierr = SNESSetInitialFunction(snes->pc, F);CHKERRQ(ierr); ierr = SNESSetInitialFunctionNorm(snes->pc, fnorm);CHKERRQ(ierr); ierr = SNESSolve(snes->pc, B, X);CHKERRQ(ierr); ierr = SNESGetConvergedReason(snes->pc,&reason);CHKERRQ(ierr); if (reason < 0 && (reason != SNES_DIVERGED_MAX_IT)) { snes->reason = SNES_DIVERGED_INNER; PetscFunctionReturn(0); } ierr = SNESGetFunction(snes->pc, &FPC, PETSC_NULL, PETSC_NULL);CHKERRQ(ierr); ierr = VecCopy(FPC, F);CHKERRQ(ierr); ierr = SNESGetFunctionNorm(snes->pc, &fnorm);CHKERRQ(ierr); ierr = VecCopy(F, D);CHKERRQ(ierr); } else { ierr = VecCopy(F, D);CHKERRQ(ierr); } powell = PETSC_FALSE; if (qn->restart_type == SNES_QN_RESTART_POWELL) { /* check restart by Powell's Criterion: |F^T H_0 Fold| > 0.2 * |Fold^T H_0 Fold| */ ierr = VecDotBegin(Dold, Dold, &DolddotDold);CHKERRQ(ierr); ierr = VecDotBegin(Dold, D, &DolddotD);CHKERRQ(ierr); ierr = VecDotBegin(D, D, &DdotD);CHKERRQ(ierr); ierr = VecDotBegin(Y, D, &YdotD);CHKERRQ(ierr); ierr = VecDotEnd(Dold, Dold, &DolddotDold);CHKERRQ(ierr); ierr = VecDotEnd(Dold, D, &DolddotD);CHKERRQ(ierr); ierr = VecDotEnd(D, D, &DdotD);CHKERRQ(ierr); ierr = VecDotEnd(Y, D, &YdotD);CHKERRQ(ierr); if (PetscAbs(PetscRealPart(DolddotD)) > qn->powell_gamma*PetscAbs(PetscRealPart(DolddotDold))) powell = PETSC_TRUE; } periodic = PETSC_FALSE; if (qn->restart_type == SNES_QN_RESTART_PERIODIC) { if (i_r>qn->m-1) periodic = PETSC_TRUE; } /* restart if either powell or periodic restart is satisfied. */ if (powell || periodic) { if (qn->monitor) { ierr = PetscViewerASCIIAddTab(qn->monitor,((PetscObject)snes)->tablevel+2);CHKERRQ(ierr); ierr = PetscViewerASCIIPrintf(qn->monitor, "restart! |%14.12e| > %4.2f*|%14.12e| or i_r = %d\n", PetscRealPart(DolddotD), qn->powell_gamma, PetscRealPart(DolddotDold), i_r);CHKERRQ(ierr); ierr = PetscViewerASCIISubtractTab(qn->monitor,((PetscObject)snes)->tablevel+2);CHKERRQ(ierr); } i_r = -1; /* general purpose update */ if (snes->ops->update) { ierr = (*snes->ops->update)(snes, snes->iter);CHKERRQ(ierr); } if (qn->scale_type == SNES_QN_SCALE_JACOBIAN) { ierr = SNESComputeJacobian(snes,X,&snes->jacobian,&snes->jacobian_pre,&flg);CHKERRQ(ierr); } } /* general purpose update */ if (snes->ops->update) { ierr = (*snes->ops->update)(snes, snes->iter);CHKERRQ(ierr); } } if (i == snes->max_its) { ierr = PetscInfo1(snes, "Maximum number of iterations has been reached: %D\n", snes->max_its);CHKERRQ(ierr); if (!snes->reason) snes->reason = SNES_DIVERGED_MAX_IT; } PetscFunctionReturn(0); }
PetscErrorCode SNESSolve_Multiblock(SNES snes) { SNES_Multiblock *mb = (SNES_Multiblock *) snes->data; Vec X, Y, F; PetscReal fnorm; PetscInt maxits, i; PetscErrorCode ierr; PetscFunctionBegin; snes->reason = SNES_CONVERGED_ITERATING; maxits = snes->max_its; /* maximum number of iterations */ X = snes->vec_sol; /* X^n */ Y = snes->vec_sol_update; /* \tilde X */ F = snes->vec_func; /* residual vector */ ierr = VecSetBlockSize(X, mb->bs);CHKERRQ(ierr); ierr = VecSetBlockSize(Y, mb->bs);CHKERRQ(ierr); ierr = VecSetBlockSize(F, mb->bs);CHKERRQ(ierr); ierr = PetscObjectTakeAccess(snes);CHKERRQ(ierr); snes->iter = 0; snes->norm = 0.; ierr = PetscObjectGrantAccess(snes);CHKERRQ(ierr); if (!snes->vec_func_init_set){ ierr = SNESComputeFunction(snes, X, F);CHKERRQ(ierr); if (snes->domainerror) { snes->reason = SNES_DIVERGED_FUNCTION_DOMAIN; PetscFunctionReturn(0); } } else { snes->vec_func_init_set = PETSC_FALSE; } if (!snes->norm_init_set) { ierr = VecNorm(F, NORM_2, &fnorm);CHKERRQ(ierr); /* fnorm <- ||F|| */ if (PetscIsInfOrNanReal(fnorm)) SETERRQ(PETSC_COMM_SELF, PETSC_ERR_FP, "Infinite or not-a-number generated in norm"); } else { fnorm = snes->norm_init; snes->norm_init_set = PETSC_FALSE; } ierr = PetscObjectTakeAccess(snes);CHKERRQ(ierr); snes->norm = fnorm; ierr = PetscObjectGrantAccess(snes);CHKERRQ(ierr); SNESLogConvHistory(snes,fnorm,0); ierr = SNESMonitor(snes,0,fnorm);CHKERRQ(ierr); /* set parameter for default relative tolerance convergence test */ snes->ttol = fnorm*snes->rtol; /* test convergence */ ierr = (*snes->ops->converged)(snes,0,0.0,0.0,fnorm,&snes->reason,snes->cnvP);CHKERRQ(ierr); if (snes->reason) PetscFunctionReturn(0); for (i = 0; i < maxits; i++) { /* Call general purpose update function */ if (snes->ops->update) { ierr = (*snes->ops->update)(snes, snes->iter);CHKERRQ(ierr); } /* Compute X^{new} from subsolves */ if (mb->type == PC_COMPOSITE_ADDITIVE) { BlockDesc blocks = mb->blocks; if (mb->defaultblocks) { /*TODO: Make an array of Vecs for this */ /*ierr = VecStrideGatherAll(X, mb->x, INSERT_VALUES);CHKERRQ(ierr);*/ while (blocks) { ierr = SNESSolve(blocks->snes, PETSC_NULL, blocks->x);CHKERRQ(ierr); blocks = blocks->next; } /*ierr = VecStrideScatterAll(mb->x, X, INSERT_VALUES);CHKERRQ(ierr);*/ } else { while (blocks) { ierr = VecScatterBegin(blocks->sctx, X, blocks->x, INSERT_VALUES, SCATTER_FORWARD);CHKERRQ(ierr); ierr = VecScatterEnd(blocks->sctx, X, blocks->x, INSERT_VALUES, SCATTER_FORWARD);CHKERRQ(ierr); ierr = SNESSolve(blocks->snes, PETSC_NULL, blocks->x);CHKERRQ(ierr); ierr = VecScatterBegin(blocks->sctx, blocks->x, X, INSERT_VALUES, SCATTER_REVERSE);CHKERRQ(ierr); ierr = VecScatterEnd(blocks->sctx, blocks->x, X, INSERT_VALUES, SCATTER_REVERSE);CHKERRQ(ierr); blocks = blocks->next; } } } else { SETERRQ1(((PetscObject) snes)->comm, PETSC_ERR_SUP, "Unsupported or unknown composition", (int) mb->type); } CHKMEMQ; /* Compute F(X^{new}) */ ierr = SNESComputeFunction(snes, X, F);CHKERRQ(ierr); ierr = VecNorm(F, NORM_2, &fnorm);CHKERRQ(ierr); if (PetscIsInfOrNanReal(fnorm)) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_FP,"Infinite or not-a-number generated norm"); if (snes->nfuncs >= snes->max_funcs) { snes->reason = SNES_DIVERGED_FUNCTION_COUNT; break; } if (snes->domainerror) { snes->reason = SNES_DIVERGED_FUNCTION_DOMAIN; PetscFunctionReturn(0); } /* Monitor convergence */ ierr = PetscObjectTakeAccess(snes);CHKERRQ(ierr); snes->iter = i+1; snes->norm = fnorm; ierr = PetscObjectGrantAccess(snes);CHKERRQ(ierr); SNESLogConvHistory(snes,snes->norm,0); ierr = SNESMonitor(snes,snes->iter,snes->norm);CHKERRQ(ierr); /* Test for convergence */ ierr = (*snes->ops->converged)(snes,snes->iter,0.0,0.0,fnorm,&snes->reason,snes->cnvP);CHKERRQ(ierr); if (snes->reason) break; } if (i == maxits) { ierr = PetscInfo1(snes, "Maximum number of iterations has been reached: %D\n", maxits);CHKERRQ(ierr); if (!snes->reason) snes->reason = SNES_DIVERGED_MAX_IT; } PetscFunctionReturn(0); }
PetscErrorCode SNESSolve_FAS(SNES snes) { PetscErrorCode ierr; PetscInt i, maxits; Vec X, F; PetscReal fnorm; SNES_FAS *fas = (SNES_FAS *)snes->data,*ffas; DM dm; PetscBool isFine; PetscFunctionBegin; maxits = snes->max_its; /* maximum number of iterations */ snes->reason = SNES_CONVERGED_ITERATING; X = snes->vec_sol; F = snes->vec_func; ierr = SNESFASCycleIsFine(snes, &isFine);CHKERRQ(ierr); /*norm setup */ ierr = PetscObjectTakeAccess(snes);CHKERRQ(ierr); snes->iter = 0; snes->norm = 0.; ierr = PetscObjectGrantAccess(snes);CHKERRQ(ierr); if (!snes->vec_func_init_set) { ierr = SNESComputeFunction(snes,X,F);CHKERRQ(ierr); if (snes->domainerror) { snes->reason = SNES_DIVERGED_FUNCTION_DOMAIN; PetscFunctionReturn(0); } } else { snes->vec_func_init_set = PETSC_FALSE; } if (!snes->norm_init_set) { ierr = VecNorm(F, NORM_2, &fnorm);CHKERRQ(ierr); /* fnorm <- ||F|| */ if (PetscIsInfOrNanReal(fnorm)) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_FP,"Infinite or not-a-number generated in norm"); ierr = PetscObjectTakeAccess(snes);CHKERRQ(ierr); } else { fnorm = snes->norm_init; snes->norm_init_set = PETSC_FALSE; } snes->norm = fnorm; ierr = PetscObjectGrantAccess(snes);CHKERRQ(ierr); SNESLogConvHistory(snes,fnorm,0); ierr = SNESMonitor(snes,0,fnorm);CHKERRQ(ierr); /* set parameter for default relative tolerance convergence test */ snes->ttol = fnorm*snes->rtol; /* test convergence */ ierr = (*snes->ops->converged)(snes,0,0.0,0.0,fnorm,&snes->reason,snes->cnvP);CHKERRQ(ierr); if (snes->reason) PetscFunctionReturn(0); if (isFine) { /* propagate scale-dependent data up the hierarchy */ ierr = SNESGetDM(snes,&dm);CHKERRQ(ierr); for (ffas=fas; ffas->next; ffas=(SNES_FAS*)ffas->next->data) { DM dmcoarse; ierr = SNESGetDM(ffas->next,&dmcoarse);CHKERRQ(ierr); ierr = DMRestrict(dm,ffas->restrct,ffas->rscale,ffas->inject,dmcoarse);CHKERRQ(ierr); dm = dmcoarse; } } for (i = 0; i < maxits; i++) { /* Call general purpose update function */ if (snes->ops->update) { ierr = (*snes->ops->update)(snes, snes->iter);CHKERRQ(ierr); } if (fas->fastype == SNES_FAS_MULTIPLICATIVE) { ierr = SNESFASCycle_Multiplicative(snes, X);CHKERRQ(ierr); } else { ierr = SNESFASCycle_Additive(snes, X);CHKERRQ(ierr); } /* check for FAS cycle divergence */ if (snes->reason != SNES_CONVERGED_ITERATING) { PetscFunctionReturn(0); } /* Monitor convergence */ ierr = PetscObjectTakeAccess(snes);CHKERRQ(ierr); snes->iter = i+1; ierr = PetscObjectGrantAccess(snes);CHKERRQ(ierr); SNESLogConvHistory(snes,snes->norm,0); ierr = SNESMonitor(snes,snes->iter,snes->norm);CHKERRQ(ierr); /* Test for convergence */ if (isFine) { ierr = (*snes->ops->converged)(snes,snes->iter,0.0,0.0,snes->norm,&snes->reason,snes->cnvP);CHKERRQ(ierr); if (snes->reason) break; } } if (i == maxits) { ierr = PetscInfo1(snes, "Maximum number of iterations has been reached: %D\n", maxits);CHKERRQ(ierr); if (!snes->reason) snes->reason = SNES_DIVERGED_MAX_IT; } PetscFunctionReturn(0); }