PetscErrorCode SNESSolve_NEWTONLS(SNES snes) { PetscErrorCode ierr; PetscInt maxits,i,lits; SNESLineSearchReason lssucceed; PetscReal fnorm,gnorm,xnorm,ynorm; Vec Y,X,F; SNESLineSearch linesearch; SNESConvergedReason reason; PetscFunctionBegin; if (snes->xl || snes->xu || snes->ops->computevariablebounds) SETERRQ1(PetscObjectComm((PetscObject)snes),PETSC_ERR_ARG_WRONGSTATE, "SNES solver %s does not support bounds", ((PetscObject)snes)->type_name); 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 */ ierr = PetscObjectSAWsTakeAccess((PetscObject)snes);CHKERRQ(ierr); snes->iter = 0; snes->norm = 0.0; ierr = PetscObjectSAWsGrantAccess((PetscObject)snes);CHKERRQ(ierr); ierr = SNESGetLineSearch(snes, &linesearch);CHKERRQ(ierr); /* compute the preconditioned function first in the case of left preconditioning with preconditioned function */ if (snes->pc && snes->pcside == PC_LEFT && snes->functype == SNES_FUNCTION_PRECONDITIONED) { ierr = SNESApplyNPC(snes,X,NULL,F);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 = VecNormBegin(F,NORM_2,&fnorm);CHKERRQ(ierr); ierr = VecNormEnd(F,NORM_2,&fnorm);CHKERRQ(ierr); } else { if (!snes->vec_func_init_set) { ierr = SNESComputeFunction(snes,X,F);CHKERRQ(ierr); } else snes->vec_func_init_set = PETSC_FALSE; } ierr = VecNorm(F,NORM_2,&fnorm);CHKERRQ(ierr); /* fnorm <- ||F|| */ SNESCheckFunctionNorm(snes,fnorm); ierr = PetscObjectSAWsTakeAccess((PetscObject)snes);CHKERRQ(ierr); snes->norm = fnorm; ierr = PetscObjectSAWsGrantAccess((PetscObject)snes);CHKERRQ(ierr); ierr = SNESLogConvergenceHistory(snes,fnorm,0);CHKERRQ(ierr); ierr = SNESMonitor(snes,0,fnorm);CHKERRQ(ierr); /* 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 (snes->pc) { if (snes->pcside == PC_RIGHT) { ierr = SNESSetInitialFunction(snes->pc, F);CHKERRQ(ierr); ierr = PetscLogEventBegin(SNES_NPCSolve,snes->pc,X,snes->vec_rhs,0);CHKERRQ(ierr); ierr = SNESSolve(snes->pc, snes->vec_rhs, X);CHKERRQ(ierr); ierr = PetscLogEventEnd(SNES_NPCSolve,snes->pc,X,snes->vec_rhs,0);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 = SNESGetNPCFunction(snes,F,&fnorm);CHKERRQ(ierr); } else if (snes->pcside == PC_LEFT && snes->functype == SNES_FUNCTION_UNPRECONDITIONED) { ierr = SNESApplyNPC(snes,X,F,F);CHKERRQ(ierr); ierr = SNESGetConvergedReason(snes->pc,&reason);CHKERRQ(ierr); if (reason < 0 && reason != SNES_DIVERGED_MAX_IT) { snes->reason = SNES_DIVERGED_INNER; PetscFunctionReturn(0); } } } /* Solve J Y = F, where J is Jacobian matrix */ ierr = SNESComputeJacobian(snes,X,snes->jacobian,snes->jacobian_pre);CHKERRQ(ierr); ierr = KSPSetOperators(snes->ksp,snes->jacobian,snes->jacobian_pre);CHKERRQ(ierr); ierr = KSPSolve(snes->ksp,F,Y);CHKERRQ(ierr); SNESCheckKSPSolve(snes); 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);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 = SNESLineSearchGetReason(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; SNESCheckFunctionNorm(snes,fnorm); 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,fnorm,&ismin);CHKERRQ(ierr); if (ismin) snes->reason = SNES_DIVERGED_LOCAL_MIN; break; } } /* Monitor convergence */ ierr = PetscObjectSAWsTakeAccess((PetscObject)snes);CHKERRQ(ierr); snes->iter = i+1; snes->norm = fnorm; ierr = PetscObjectSAWsGrantAccess((PetscObject)snes);CHKERRQ(ierr); ierr = SNESLogConvergenceHistory(snes,snes->norm,lits);CHKERRQ(ierr); 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_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); }