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_NRichardson(SNES snes) { Vec X, Y, F; PetscReal xnorm, fnorm, ynorm; PetscInt maxits, i; PetscErrorCode ierr; SNESLineSearchReason lsresult; 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->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 = PetscObjectSAWsTakeAccess((PetscObject)snes); CHKERRQ(ierr); snes->iter = 0; snes->norm = 0.; ierr = PetscObjectSAWsGrantAccess((PetscObject)snes); CHKERRQ(ierr); if (snes->pc && 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 = VecNorm(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); SNESCheckFunctionNorm(snes,fnorm); } if (snes->pc && snes->functype == SNES_FUNCTION_UNPRECONDITIONED) { ierr = SNESApplyNPC(snes,X,F,Y); CHKERRQ(ierr); ierr = SNESGetConvergedReason(snes->pc,&reason); CHKERRQ(ierr); if (reason < 0 && reason != SNES_DIVERGED_MAX_IT) { snes->reason = SNES_DIVERGED_INNER; PetscFunctionReturn(0); } } else { ierr = VecCopy(F,Y); CHKERRQ(ierr); } 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); /* Call general purpose update function */ if (snes->ops->update) { ierr = (*snes->ops->update)(snes, snes->iter); 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 = 1; i < maxits+1; i++) { ierr = SNESLineSearchApply(snes->linesearch, X, F, &fnorm, Y); CHKERRQ(ierr); ierr = SNESLineSearchGetReason(snes->linesearch, &lsresult); CHKERRQ(ierr); ierr = SNESLineSearchGetNorms(snes->linesearch, &xnorm, &fnorm, &ynorm); CHKERRQ(ierr); if (lsresult) { if (++snes->numFailures >= snes->maxFailures) { snes->reason = SNES_DIVERGED_LINE_SEARCH; break; } } if (snes->nfuncs >= snes->max_funcs) { snes->reason = SNES_DIVERGED_FUNCTION_COUNT; break; } /* Monitor convergence */ ierr = PetscObjectSAWsTakeAccess((PetscObject)snes); CHKERRQ(ierr); snes->iter = i; snes->norm = fnorm; ierr = PetscObjectSAWsGrantAccess((PetscObject)snes); CHKERRQ(ierr); ierr = SNESLogConvergenceHistory(snes,snes->norm,0); 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; /* Call general purpose update function */ if (snes->ops->update) { ierr = (*snes->ops->update)(snes, snes->iter); CHKERRQ(ierr); } if (snes->pc) { if (snes->functype == SNES_FUNCTION_PRECONDITIONED) { ierr = SNESApplyNPC(snes,X,NULL,Y); CHKERRQ(ierr); ierr = VecNorm(F,NORM_2,&fnorm); CHKERRQ(ierr); ierr = VecCopy(Y,F); CHKERRQ(ierr); } else { ierr = SNESApplyNPC(snes,X,F,Y); CHKERRQ(ierr); } ierr = SNESGetConvergedReason(snes->pc,&reason); CHKERRQ(ierr); if (reason < 0 && reason != SNES_DIVERGED_MAX_IT) { snes->reason = SNES_DIVERGED_INNER; PetscFunctionReturn(0); } } else { ierr = VecCopy(F,Y); CHKERRQ(ierr); } } if (i == maxits+1) { 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); }
/* SNESSolve_VINEWTONSSLS - Solves the complementarity problem with a semismooth Newton method using a line search. Input Parameters: . snes - the SNES context Application Interface Routine: SNESSolve() Notes: This implements essentially a semismooth Newton method with a line search. The default line search does not do any line search but rather takes a full Newton step. Developer Note: the code in this file should be slightly modified so that this routine need not exist and the SNESSolve_NEWTONLS() routine is called directly with the appropriate wrapped function and Jacobian evaluations */ PetscErrorCode SNESSolve_VINEWTONSSLS(SNES snes) { SNES_VINEWTONSSLS *vi = (SNES_VINEWTONSSLS*)snes->data; PetscErrorCode ierr; PetscInt maxits,i,lits; SNESLineSearchReason lssucceed; PetscReal gnorm,xnorm=0,ynorm; Vec Y,X,F; KSPConvergedReason kspreason; DM dm; DMSNES sdm; PetscFunctionBegin; ierr = SNESGetDM(snes,&dm);CHKERRQ(ierr); ierr = DMGetDMSNES(dm,&sdm);CHKERRQ(ierr); vi->computeuserfunction = sdm->ops->computefunction; sdm->ops->computefunction = SNESVIComputeFunction; 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 = PetscObjectSAWsTakeAccess((PetscObject)snes);CHKERRQ(ierr); snes->iter = 0; snes->norm = 0.0; ierr = PetscObjectSAWsGrantAccess((PetscObject)snes);CHKERRQ(ierr); ierr = SNESVIProjectOntoBounds(snes,X);CHKERRQ(ierr); ierr = SNESComputeFunction(snes,X,vi->phi);CHKERRQ(ierr); if (snes->domainerror) { snes->reason = SNES_DIVERGED_FUNCTION_DOMAIN; sdm->ops->computefunction = vi->computeuserfunction; PetscFunctionReturn(0); } /* Compute Merit function */ ierr = SNESVIComputeMeritFunction(vi->phi,&vi->merit,&vi->phinorm);CHKERRQ(ierr); ierr = VecNormBegin(X,NORM_2,&xnorm);CHKERRQ(ierr); /* xnorm <- ||x|| */ ierr = VecNormEnd(X,NORM_2,&xnorm);CHKERRQ(ierr); SNESCheckFunctionNorm(snes,vi->merit); ierr = PetscObjectSAWsTakeAccess((PetscObject)snes);CHKERRQ(ierr); snes->norm = vi->phinorm; ierr = PetscObjectSAWsGrantAccess((PetscObject)snes);CHKERRQ(ierr); ierr = SNESLogConvergenceHistory(snes,vi->phinorm,0);CHKERRQ(ierr); ierr = SNESMonitor(snes,0,vi->phinorm);CHKERRQ(ierr); /* test convergence */ ierr = (*snes->ops->converged)(snes,0,0.0,0.0,vi->phinorm,&snes->reason,snes->cnvP);CHKERRQ(ierr); if (snes->reason) { sdm->ops->computefunction = vi->computeuserfunction; 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 = Phi, where J is the semismooth jacobian */ /* Get the jacobian -- note that the function must be the original function for snes_fd and snes_fd_color to work for this*/ sdm->ops->computefunction = vi->computeuserfunction; ierr = SNESComputeJacobian(snes,X,snes->jacobian,snes->jacobian_pre);CHKERRQ(ierr); SNESCheckJacobianDomainerror(snes); sdm->ops->computefunction = SNESVIComputeFunction; /* Get the diagonal shift and row scaling vectors */ ierr = SNESVIComputeBsubdifferentialVectors(snes,X,F,snes->jacobian,vi->Da,vi->Db);CHKERRQ(ierr); /* Compute the semismooth jacobian */ ierr = SNESVIComputeJacobian(snes->jacobian,snes->jacobian_pre,vi->Da,vi->Db);CHKERRQ(ierr); /* Compute the merit function gradient */ ierr = SNESVIComputeMeritFunctionGradient(snes->jacobian,vi->phi,vi->dpsi);CHKERRQ(ierr); ierr = KSPSetOperators(snes->ksp,snes->jacobian,snes->jacobian_pre);CHKERRQ(ierr); ierr = KSPSolve(snes->ksp,vi->phi,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 (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 = vi->phinorm; ierr = SNESLineSearchApply(snes->linesearch, X, vi->phi, &gnorm, Y);CHKERRQ(ierr); ierr = SNESLineSearchGetReason(snes->linesearch, &lssucceed);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)vi->phinorm,(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; sdm->ops->computefunction = vi->computeuserfunction; PetscFunctionReturn(0); } if (lssucceed) { if (++snes->numFailures >= snes->maxFailures) { PetscBool ismin; snes->reason = SNES_DIVERGED_LINE_SEARCH; ierr = SNESVICheckLocalMin_Private(snes,snes->jacobian,vi->phi,X,gnorm,&ismin);CHKERRQ(ierr); if (ismin) snes->reason = SNES_DIVERGED_LOCAL_MIN; break; } } /* Update function and solution vectors */ vi->phinorm = gnorm; vi->merit = 0.5*vi->phinorm*vi->phinorm; /* Monitor convergence */ ierr = PetscObjectSAWsTakeAccess((PetscObject)snes);CHKERRQ(ierr); snes->iter = i+1; snes->norm = vi->phinorm; snes->xnorm = xnorm; snes->ynorm = ynorm; 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, xnorm = || X || */ if (snes->ops->converged != SNESConvergedSkip) { ierr = VecNorm(X,NORM_2,&xnorm);CHKERRQ(ierr); } ierr = (*snes->ops->converged)(snes,snes->iter,xnorm,ynorm,vi->phinorm,&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; } sdm->ops->computefunction = vi->computeuserfunction; PetscFunctionReturn(0); }
static PetscErrorCode SNESSolve_QN(SNES snes) { PetscErrorCode ierr; SNES_QN *qn = (SNES_QN*) snes->data; Vec X,Xold; Vec F,W; Vec Y,D,Dold; PetscInt i, i_r; PetscReal fnorm,xnorm,ynorm,gnorm; SNESLineSearchReason lssucceed; PetscBool powell,periodic; PetscScalar DolddotD,DolddotDold; SNESConvergedReason reason; /* basically just a regular newton's method except for the application of the Jacobian */ 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); } ierr = PetscCitationsRegister(SNESCitation,&SNEScite);CHKERRQ(ierr); F = snes->vec_func; /* residual vector */ Y = snes->vec_sol_update; /* search direction generated by J^-1D*/ W = snes->work[3]; 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 = PetscObjectSAWsTakeAccess((PetscObject)snes);CHKERRQ(ierr); snes->iter = 0; snes->norm = 0.; ierr = PetscObjectSAWsGrantAccess((PetscObject)snes);CHKERRQ(ierr); 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 = VecNorm(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); SNESCheckFunctionNorm(snes,fnorm); } if (snes->pc && snes->pcside == PC_LEFT && snes->functype == SNES_FUNCTION_UNPRECONDITIONED) { ierr = SNESApplyNPC(snes,X,F,D);CHKERRQ(ierr); ierr = SNESGetConvergedReason(snes->pc,&reason);CHKERRQ(ierr); if (reason < 0 && reason != SNES_DIVERGED_MAX_IT) { snes->reason = SNES_DIVERGED_INNER; PetscFunctionReturn(0); } } else { ierr = VecCopy(F,D);CHKERRQ(ierr); } 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); if (snes->pc && snes->pcside == PC_RIGHT) { ierr = PetscLogEventBegin(SNES_NPCSolve,snes->pc,X,0,0);CHKERRQ(ierr); ierr = SNESSolve(snes->pc,snes->vec_rhs,X);CHKERRQ(ierr); ierr = PetscLogEventEnd(SNES_NPCSolve,snes->pc,X,0,0);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); ierr = VecCopy(F,D);CHKERRQ(ierr); } /* scale the initial update */ if (qn->scale_type == SNES_QN_SCALE_JACOBIAN) { ierr = SNESComputeJacobian(snes,X,snes->jacobian,snes->jacobian_pre);CHKERRQ(ierr); ierr = KSPSetOperators(snes->ksp,snes->jacobian,snes->jacobian_pre);CHKERRQ(ierr); } for (i = 0, i_r = 0; i < snes->max_its; i++, i_r++) { if (qn->scale_type == SNES_QN_SCALE_SHANNO && i_r > 0) { PetscScalar ff,xf; ierr = VecCopy(Dold,Y);CHKERRQ(ierr); ierr = VecCopy(Xold,W);CHKERRQ(ierr); ierr = VecAXPY(Y,-1.0,D);CHKERRQ(ierr); ierr = VecAXPY(W,-1.0,X);CHKERRQ(ierr); ierr = VecDotBegin(Y,Y,&ff);CHKERRQ(ierr); ierr = VecDotBegin(W,Y,&xf);CHKERRQ(ierr); ierr = VecDotEnd(Y,Y,&ff);CHKERRQ(ierr); ierr = VecDotEnd(W,Y,&xf);CHKERRQ(ierr); qn->scaling = PetscRealPart(xf)/PetscRealPart(ff); } 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);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; ierr = SNESLineSearchGetReason(snes->linesearch, &lssucceed);CHKERRQ(ierr); ierr = SNESLineSearchGetNorms(snes->linesearch, &xnorm, &fnorm, &ynorm);CHKERRQ(ierr); if (lssucceed) { if (++snes->numFailures >= snes->maxFailures) { snes->reason = SNES_DIVERGED_LINE_SEARCH; break; } } 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); if (snes->pc && snes->pcside == PC_RIGHT) { ierr = PetscLogEventBegin(SNES_NPCSolve,snes->pc,X,0,0);CHKERRQ(ierr); ierr = SNESSolve(snes->pc,snes->vec_rhs,X);CHKERRQ(ierr); ierr = PetscLogEventEnd(SNES_NPCSolve,snes->pc,X,0,0);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); } ierr = SNESSetIterationNumber(snes, i+1);CHKERRQ(ierr); snes->norm = fnorm; ierr = SNESLogConvergenceHistory(snes,snes->norm,snes->iter);CHKERRQ(ierr); 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_LEFT && snes->functype == SNES_FUNCTION_UNPRECONDITIONED) { ierr = SNESApplyNPC(snes,X,F,D);CHKERRQ(ierr); ierr = SNESGetConvergedReason(snes->pc,&reason);CHKERRQ(ierr); if (reason < 0 && reason != SNES_DIVERGED_MAX_IT) { snes->reason = SNES_DIVERGED_INNER; PetscFunctionReturn(0); } } 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| */ if (qn->scale_type == SNES_QN_SCALE_JACOBIAN) { ierr = MatMult(snes->jacobian_pre,Dold,W);CHKERRQ(ierr); } else { ierr = VecCopy(Dold,W);CHKERRQ(ierr); } ierr = VecDotBegin(W, Dold, &DolddotDold);CHKERRQ(ierr); ierr = VecDotBegin(W, D, &DolddotD);CHKERRQ(ierr); ierr = VecDotEnd(W, Dold, &DolddotDold);CHKERRQ(ierr); ierr = VecDotEnd(W, D, &DolddotD);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);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 SNESNGMRESSelect_Private(SNES snes,PetscInt k_restart,Vec XM,Vec FM,PetscReal xMnorm,PetscReal fMnorm,PetscReal yMnorm,Vec XA,Vec FA,PetscReal xAnorm,PetscReal fAnorm,PetscReal yAnorm,PetscReal dnorm,PetscReal fminnorm,PetscReal dminnorm,Vec X,Vec F,Vec Y,PetscReal *xnorm,PetscReal *fnorm,PetscReal *ynorm) { SNES_NGMRES *ngmres = (SNES_NGMRES*) snes->data; PetscErrorCode ierr; SNESLineSearchReason lssucceed; PetscBool selectA; PetscFunctionBegin; if (ngmres->select_type == SNES_NGMRES_SELECT_LINESEARCH) { /* X = X + \lambda(XA - X) */ if (ngmres->monitor) { ierr = PetscViewerASCIIPrintf(ngmres->monitor,"||F_A||_2 = %e, ||F_M||_2 = %e\n",fAnorm,fMnorm);CHKERRQ(ierr); } ierr = VecCopy(FM,F);CHKERRQ(ierr); ierr = VecCopy(XM,X);CHKERRQ(ierr); ierr = VecCopy(XA,Y);CHKERRQ(ierr); ierr = VecAYPX(Y,-1.0,X);CHKERRQ(ierr); *fnorm = fMnorm; ierr = SNESLineSearchApply(ngmres->additive_linesearch,X,F,fnorm,Y);CHKERRQ(ierr); ierr = SNESLineSearchGetReason(ngmres->additive_linesearch,&lssucceed);CHKERRQ(ierr); ierr = SNESLineSearchGetNorms(ngmres->additive_linesearch,xnorm,fnorm,ynorm);CHKERRQ(ierr); if (lssucceed) { if (++snes->numFailures >= snes->maxFailures) { snes->reason = SNES_DIVERGED_LINE_SEARCH; PetscFunctionReturn(0); } } if (ngmres->monitor) { ierr = PetscViewerASCIIPrintf(ngmres->monitor,"Additive solution: ||F||_2 = %e\n",*fnorm);CHKERRQ(ierr); } } else if (ngmres->select_type == SNES_NGMRES_SELECT_DIFFERENCE) { selectA = PETSC_TRUE; /* Conditions for choosing the accelerated answer */ /* Criterion A -- the norm of the function isn't increased above the minimum by too much */ if (fAnorm >= ngmres->gammaA*fminnorm) selectA = PETSC_FALSE; /* Criterion B -- the choice of x^A isn't too close to some other choice */ if (ngmres->epsilonB*dnorm<dminnorm || PetscSqrtReal(*fnorm)<ngmres->deltaB*PetscSqrtReal(fminnorm)) { } else selectA=PETSC_FALSE; if (selectA) { if (ngmres->monitor) { ierr = PetscViewerASCIIPrintf(ngmres->monitor,"picked X_A, ||F_A||_2 = %e, ||F_M||_2 = %e\n",fAnorm,fMnorm);CHKERRQ(ierr); } /* copy it over */ *xnorm = xAnorm; *fnorm = fAnorm; *ynorm = yAnorm; ierr = VecCopy(FA,F);CHKERRQ(ierr); ierr = VecCopy(XA,X);CHKERRQ(ierr); } else { if (ngmres->monitor) { ierr = PetscViewerASCIIPrintf(ngmres->monitor,"picked X_M, ||F_A||_2 = %e, ||F_M||_2 = %e\n",fAnorm,fMnorm);CHKERRQ(ierr); } *xnorm = xMnorm; *fnorm = fMnorm; *ynorm = yMnorm; ierr = VecCopy(XM,Y);CHKERRQ(ierr); ierr = VecAXPY(Y,-1.0,X);CHKERRQ(ierr); ierr = VecCopy(FM,F);CHKERRQ(ierr); ierr = VecCopy(XM,X);CHKERRQ(ierr); } } else { /* none */ *xnorm = xAnorm; *fnorm = fAnorm; *ynorm = yAnorm; ierr = VecCopy(FA,F);CHKERRQ(ierr); ierr = VecCopy(XA,X);CHKERRQ(ierr); } PetscFunctionReturn(0); }
/* The additive cycle looks like: xhat = x xhat = dS(x, b) x = coarsecorrection(xhat, b_d) x = x + nu*(xhat - x); (optional) x = uS(x, b) With the coarse RHS (defect correction) as below. */ PetscErrorCode SNESFASCycle_Additive(SNES snes, Vec X) { Vec F, B, Xhat; Vec X_c, Xo_c, F_c, B_c; PetscErrorCode ierr; SNESConvergedReason reason; PetscReal xnorm, fnorm, ynorm; SNESLineSearchReason lsresult; SNES next; Mat restrct, interpolate; SNES_FAS *fas = (SNES_FAS*)snes->data,*fasc; PetscFunctionBegin; ierr = SNESFASCycleGetCorrection(snes, &next);CHKERRQ(ierr); F = snes->vec_func; B = snes->vec_rhs; Xhat = snes->work[1]; ierr = VecCopy(X, Xhat);CHKERRQ(ierr); /* recurse first */ if (next) { fasc = (SNES_FAS*)next->data; ierr = SNESFASCycleGetRestriction(snes, &restrct);CHKERRQ(ierr); ierr = SNESFASCycleGetInterpolation(snes, &interpolate);CHKERRQ(ierr); if (fas->eventresidual) {ierr = PetscLogEventBegin(fas->eventresidual,0,0,0,0);CHKERRQ(ierr);} ierr = SNESComputeFunction(snes, Xhat, F);CHKERRQ(ierr); if (fas->eventresidual) {ierr = PetscLogEventEnd(fas->eventresidual,0,0,0,0);CHKERRQ(ierr);} ierr = VecNorm(F, NORM_2, &fnorm);CHKERRQ(ierr); X_c = next->vec_sol; Xo_c = next->work[0]; F_c = next->vec_func; B_c = next->vec_rhs; ierr = SNESFASRestrict(snes,Xhat,Xo_c);CHKERRQ(ierr); /* restrict the defect */ ierr = MatRestrict(restrct, F, B_c);CHKERRQ(ierr); /* solve the coarse problem corresponding to F^c(x^c) = b^c = Rb + F^c(Rx) - RF(x) */ if (fasc->eventresidual) {ierr = PetscLogEventBegin(fasc->eventresidual,0,0,0,0);CHKERRQ(ierr);} ierr = SNESComputeFunction(next, Xo_c, F_c);CHKERRQ(ierr); if (fasc->eventresidual) {ierr = PetscLogEventEnd(fasc->eventresidual,0,0,0,0);CHKERRQ(ierr);} ierr = VecCopy(B_c, X_c);CHKERRQ(ierr); ierr = VecCopy(F_c, B_c);CHKERRQ(ierr); ierr = VecCopy(X_c, F_c);CHKERRQ(ierr); /* set initial guess of the coarse problem to the projected fine solution */ ierr = VecCopy(Xo_c, X_c);CHKERRQ(ierr); /* recurse */ ierr = SNESSetInitialFunction(next, F_c);CHKERRQ(ierr); ierr = SNESSolve(next, B_c, X_c);CHKERRQ(ierr); /* smooth on this level */ ierr = SNESFASDownSmooth_Private(snes, B, X, F, &fnorm);CHKERRQ(ierr); ierr = SNESGetConvergedReason(next,&reason);CHKERRQ(ierr); if (reason < 0 && reason != SNES_DIVERGED_MAX_IT) { snes->reason = SNES_DIVERGED_INNER; PetscFunctionReturn(0); } /* correct as x <- x + I(x^c - Rx)*/ ierr = VecAYPX(X_c, -1.0, Xo_c);CHKERRQ(ierr); ierr = MatInterpolate(interpolate, X_c, Xhat);CHKERRQ(ierr); /* additive correction of the coarse direction*/ ierr = SNESLineSearchApply(snes->linesearch, X, F, &fnorm, Xhat);CHKERRQ(ierr); ierr = SNESLineSearchGetReason(snes->linesearch, &lsresult);CHKERRQ(ierr); ierr = SNESLineSearchGetNorms(snes->linesearch, &xnorm, &snes->norm, &ynorm);CHKERRQ(ierr); if (lsresult) { if (++snes->numFailures >= snes->maxFailures) { snes->reason = SNES_DIVERGED_LINE_SEARCH; PetscFunctionReturn(0); } } } else { ierr = SNESFASDownSmooth_Private(snes, B, X, F, &snes->norm);CHKERRQ(ierr); } PetscFunctionReturn(0); }
PetscErrorCode SNESSolve_NCG(SNES snes) { SNES_NCG *ncg = (SNES_NCG*)snes->data; Vec X,dX,lX,F,dXold; PetscReal fnorm, ynorm, xnorm, beta = 0.0; PetscScalar dXdotdX, dXolddotdXold, dXdotdXold, lXdotdX, lXdotdXold; PetscInt maxits, i; PetscErrorCode ierr; SNESLineSearchReason lsresult = SNES_LINESEARCH_SUCCEEDED; 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); } ierr = PetscCitationsRegister(SNESCitation,&SNEScite);CHKERRQ(ierr); snes->reason = SNES_CONVERGED_ITERATING; maxits = snes->max_its; /* maximum number of iterations */ X = snes->vec_sol; /* X^n */ dXold = 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 */ ierr = SNESGetLineSearch(snes, &linesearch);CHKERRQ(ierr); ierr = PetscObjectSAWsTakeAccess((PetscObject)snes);CHKERRQ(ierr); snes->iter = 0; snes->norm = 0.; ierr = PetscObjectSAWsGrantAccess((PetscObject)snes);CHKERRQ(ierr); /* compute the initial function and preconditioned update dX */ if (snes->pc && snes->functype == SNES_FUNCTION_PRECONDITIONED) { ierr = SNESApplyNPC(snes,X,NULL,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 = VecCopy(dX,F);CHKERRQ(ierr); ierr = VecNorm(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; /* convergence test */ ierr = VecNorm(F,NORM_2,&fnorm);CHKERRQ(ierr); SNESCheckFunctionNorm(snes,fnorm); ierr = VecCopy(F,dX);CHKERRQ(ierr); } if (snes->pc) { if (snes->functype == SNES_FUNCTION_UNPRECONDITIONED) { ierr = SNESApplyNPC(snes,X,F,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 = VecCopy(dX,lX);CHKERRQ(ierr); ierr = VecDot(dX, dX, &dXdotdX);CHKERRQ(ierr); 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); /* 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 */ for (i = 1; i < maxits + 1; i++) { /* some update types require the old update direction or conjugate direction */ if (ncg->type != SNES_NCG_FR) { ierr = VecCopy(dX, dXold);CHKERRQ(ierr); } ierr = SNESLineSearchApply(linesearch,X,F,&fnorm,lX);CHKERRQ(ierr); ierr = SNESLineSearchGetReason(linesearch, &lsresult);CHKERRQ(ierr); ierr = SNESLineSearchGetNorms(linesearch, &xnorm, &fnorm, &ynorm);CHKERRQ(ierr); if (lsresult) { 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); } /* Monitor convergence */ ierr = PetscObjectSAWsTakeAccess((PetscObject)snes);CHKERRQ(ierr); snes->iter = i; snes->norm = fnorm; ierr = PetscObjectSAWsGrantAccess((PetscObject)snes);CHKERRQ(ierr); ierr = SNESLogConvergenceHistory(snes,snes->norm,0);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) PetscFunctionReturn(0); /* Call general purpose update function */ if (snes->ops->update) { ierr = (*snes->ops->update)(snes, snes->iter);CHKERRQ(ierr); } if (snes->pc) { if (snes->functype == SNES_FUNCTION_PRECONDITIONED) { ierr = SNESApplyNPC(snes,X,NULL,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 = VecCopy(dX,F);CHKERRQ(ierr); } else { ierr = SNESApplyNPC(snes,X,F,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); } } } 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 */ dXolddotdXold= dXdotdX; ierr = VecDot(dX, dX, &dXdotdX);CHKERRQ(ierr); beta = PetscRealPart(dXdotdX / dXolddotdXold); break; case SNES_NCG_PRP: /* Polak-Ribiere-Poylak */ dXolddotdXold= dXdotdX; ierr = VecDotBegin(dX, dX, &dXdotdXold);CHKERRQ(ierr); ierr = VecDotBegin(dXold, dX, &dXdotdXold);CHKERRQ(ierr); ierr = VecDotEnd(dX, dX, &dXdotdX);CHKERRQ(ierr); ierr = VecDotEnd(dXold, dX, &dXdotdXold);CHKERRQ(ierr); beta = PetscRealPart(((dXdotdX - dXdotdXold) / dXolddotdXold)); if (beta < 0.0) beta = 0.0; /* restart */ break; case SNES_NCG_HS: /* Hestenes-Stiefel */ ierr = VecDotBegin(dX, dX, &dXdotdX);CHKERRQ(ierr); ierr = VecDotBegin(dX, dXold, &dXdotdXold);CHKERRQ(ierr); ierr = VecDotBegin(lX, dX, &lXdotdX);CHKERRQ(ierr); ierr = VecDotBegin(lX, dXold, &lXdotdXold);CHKERRQ(ierr); ierr = VecDotEnd(dX, dX, &dXdotdX);CHKERRQ(ierr); ierr = VecDotEnd(dX, dXold, &dXdotdXold);CHKERRQ(ierr); ierr = VecDotEnd(lX, dX, &lXdotdX);CHKERRQ(ierr); ierr = VecDotEnd(lX, dXold, &lXdotdXold);CHKERRQ(ierr); beta = PetscRealPart((dXdotdX - dXdotdXold) / (lXdotdX - lXdotdXold)); break; case SNES_NCG_DY: /* Dai-Yuan */ ierr = VecDotBegin(dX, dX, &dXdotdX);CHKERRQ(ierr); ierr = VecDotBegin(lX, dX, &lXdotdX);CHKERRQ(ierr); ierr = VecDotBegin(lX, dXold, &lXdotdXold);CHKERRQ(ierr); ierr = VecDotEnd(dX, dX, &dXdotdX);CHKERRQ(ierr); ierr = VecDotEnd(lX, dX, &lXdotdX);CHKERRQ(ierr); ierr = VecDotEnd(lX, dXold, &lXdotdXold);CHKERRQ(ierr); beta = PetscRealPart(dXdotdX / (lXdotdXold - lXdotdX));CHKERRQ(ierr); break; case SNES_NCG_CD: /* Conjugate Descent */ ierr = VecDotBegin(dX, dX, &dXdotdX);CHKERRQ(ierr); ierr = VecDotBegin(lX, dXold, &lXdotdXold);CHKERRQ(ierr); ierr = VecDotEnd(dX, dX, &dXdotdX);CHKERRQ(ierr); ierr = VecDotEnd(lX, dXold, &lXdotdXold);CHKERRQ(ierr); beta = PetscRealPart(dXdotdX / lXdotdXold);CHKERRQ(ierr); break; } if (ncg->monitor) { ierr = PetscViewerASCIIPrintf(ncg->monitor, "beta = %e\n", (double)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); }