/* Defines the action of the downsmoother */ PetscErrorCode SNESFASDownSmooth_Private(SNES snes, Vec B, Vec X, Vec F, PetscReal *fnorm) { PetscErrorCode ierr = 0; SNESConvergedReason reason; Vec FPC; SNES smoothd; PetscFunctionBegin; ierr = SNESFASCycleGetSmootherDown(snes, &smoothd);CHKERRQ(ierr); ierr = SNESSetInitialFunction(smoothd, F);CHKERRQ(ierr); ierr = SNESSetInitialFunctionNorm(smoothd, *fnorm);CHKERRQ(ierr); ierr = SNESSolve(smoothd, B, X);CHKERRQ(ierr); /* check convergence reason for the smoother */ ierr = SNESGetConvergedReason(smoothd,&reason);CHKERRQ(ierr); if (reason < 0 && !(reason == SNES_DIVERGED_MAX_IT || reason == SNES_DIVERGED_LOCAL_MIN)) { snes->reason = SNES_DIVERGED_INNER; PetscFunctionReturn(0); } ierr = SNESGetFunction(smoothd, &FPC, PETSC_NULL, PETSC_NULL);CHKERRQ(ierr); ierr = VecCopy(FPC, F);CHKERRQ(ierr); ierr = SNESGetFunctionNorm(smoothd, fnorm);CHKERRQ(ierr); PetscFunctionReturn(0); }
PetscErrorCode SNESSolve_NRichardson(SNES snes) { Vec X, Y, F; PetscReal xnorm, fnorm, ynorm; PetscInt maxits, i; PetscErrorCode ierr; PetscBool lsSuccess; SNESConvergedReason reason; 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 = PetscObjectAMSTakeAccess((PetscObject)snes);CHKERRQ(ierr); snes->iter = 0; snes->norm = 0.; ierr = PetscObjectAMSGrantAccess((PetscObject)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)) { snes->reason = SNES_DIVERGED_FNORM_NAN; PetscFunctionReturn(0); } } else { fnorm = snes->norm_init; snes->norm_init_set = PETSC_FALSE; } ierr = PetscObjectAMSTakeAccess((PetscObject)snes);CHKERRQ(ierr); snes->norm = fnorm; ierr = PetscObjectAMSGrantAccess((PetscObject)snes);CHKERRQ(ierr); ierr = SNESLogConvergenceHistory(snes,fnorm,0);CHKERRQ(ierr); 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++) { lsSuccess = PETSC_TRUE; /* 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,Y);CHKERRQ(ierr); ierr = SNESSetInitialFunction(snes->pc, F);CHKERRQ(ierr); ierr = SNESSetInitialFunctionNorm(snes->pc, fnorm);CHKERRQ(ierr); ierr = PetscLogEventBegin(SNES_NPCSolve,snes->pc,Y,snes->vec_rhs,0);CHKERRQ(ierr); ierr = SNESSolve(snes->pc, snes->vec_rhs, Y);CHKERRQ(ierr); ierr = PetscLogEventEnd(SNES_NPCSolve,snes->pc,Y,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 = VecAYPX(Y,-1.0,X);CHKERRQ(ierr); } else { ierr = VecCopy(F,Y);CHKERRQ(ierr); } ierr = SNESLineSearchApply(snes->linesearch, X, F, &fnorm, Y);CHKERRQ(ierr); ierr = SNESLineSearchGetNorms(snes->linesearch, &xnorm, &fnorm, &ynorm);CHKERRQ(ierr); ierr = SNESLineSearchGetSuccess(snes->linesearch, &lsSuccess);CHKERRQ(ierr); if (!lsSuccess) { 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; } if (snes->domainerror) { snes->reason = SNES_DIVERGED_FUNCTION_DOMAIN; PetscFunctionReturn(0); } /* Monitor convergence */ ierr = PetscObjectAMSTakeAccess((PetscObject)snes);CHKERRQ(ierr); snes->iter = i+1; snes->norm = fnorm; ierr = PetscObjectAMSGrantAccess((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; } 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); }
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); }
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); }