/*@ PetscDTGaussQuadrature - create Gauss quadrature Not Collective Input Arguments: + npoints - number of points . a - left end of interval (often-1) - b - right end of interval (often +1) Output Arguments: + x - quadrature points - w - quadrature weights Level: intermediate References: Golub and Welsch, Calculation of Quadrature Rules, Math. Comp. 23(106), 221--230, 1969. .seealso: PetscDTLegendreEval() @*/ PetscErrorCode PetscDTGaussQuadrature(PetscInt npoints,PetscReal a,PetscReal b,PetscReal *x,PetscReal *w) { PetscErrorCode ierr; PetscInt i; PetscReal *work; PetscScalar *Z; PetscBLASInt N,LDZ,info; PetscFunctionBegin; ierr = PetscCitationsRegister(GaussCitation, &GaussCite);CHKERRQ(ierr); /* Set up the Golub-Welsch system */ for (i=0; i<npoints; i++) { x[i] = 0; /* diagonal is 0 */ if (i) w[i-1] = 0.5 / PetscSqrtReal(1 - 1./PetscSqr(2*i)); } ierr = PetscMalloc2(npoints*npoints,&Z,PetscMax(1,2*npoints-2),&work);CHKERRQ(ierr); ierr = PetscBLASIntCast(npoints,&N);CHKERRQ(ierr); LDZ = N; ierr = PetscFPTrapPush(PETSC_FP_TRAP_OFF);CHKERRQ(ierr); PetscStackCallBLAS("LAPACKsteqr",LAPACKsteqr_("I",&N,x,w,Z,&LDZ,work,&info)); ierr = PetscFPTrapPop();CHKERRQ(ierr); if (info) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_PLIB,"xSTEQR error"); for (i=0; i<(npoints+1)/2; i++) { PetscReal y = 0.5 * (-x[i] + x[npoints-i-1]); /* enforces symmetry */ x[i] = (a+b)/2 - y*(b-a)/2; x[npoints-i-1] = (a+b)/2 + y*(b-a)/2; w[i] = w[npoints-1-i] = 0.5*(b-a)*(PetscSqr(PetscAbsScalar(Z[i*npoints])) + PetscSqr(PetscAbsScalar(Z[(npoints-i-1)*npoints]))); } ierr = PetscFree2(Z,work);CHKERRQ(ierr); PetscFunctionReturn(0); }
/* KSPSolve_PIPEFGMRES - This routine applies the PIPEFGMRES method. Input Parameter: . ksp - the Krylov space object that was set to use pipefgmres Output Parameter: . outits - number of iterations used */ static PetscErrorCode KSPSolve_PIPEFGMRES(KSP ksp) { PetscErrorCode ierr; PetscInt its,itcount; KSP_PIPEFGMRES *pipefgmres = (KSP_PIPEFGMRES*)ksp->data; PetscBool guess_zero = ksp->guess_zero; PetscFunctionBegin; /* We have not checked these routines for use with complex numbers. The inner products are likely not defined correctly for that case */ #if (defined(PETSC_USE_COMPLEX) && !defined(PETSC_SKIP_COMPLEX)) SETERRQ(PETSC_COMM_WORLD,PETSC_ERR_SUP,"PIPEFGMRES has not been implemented for use with complex scalars"); #endif ierr = PetscCitationsRegister(citation,&cited);CHKERRQ(ierr); if (ksp->calc_sings && !pipefgmres->Rsvd) SETERRQ(PetscObjectComm((PetscObject)ksp),PETSC_ERR_ORDER,"Must call KSPSetComputeSingularValues() before KSPSetUp() is called"); ierr = PetscObjectSAWsTakeAccess((PetscObject)ksp);CHKERRQ(ierr); ksp->its = 0; ierr = PetscObjectSAWsGrantAccess((PetscObject)ksp);CHKERRQ(ierr); itcount = 0; ksp->reason = KSP_CONVERGED_ITERATING; while (!ksp->reason) { ierr = KSPInitialResidual(ksp,ksp->vec_sol,VEC_TEMP,VEC_TEMP_MATOP,VEC_VV(0),ksp->vec_rhs);CHKERRQ(ierr); ierr = KSPPIPEFGMRESCycle(&its,ksp);CHKERRQ(ierr); itcount += its; if (itcount >= ksp->max_it) { if (!ksp->reason) ksp->reason = KSP_DIVERGED_ITS; break; } ksp->guess_zero = PETSC_FALSE; /* every future call to KSPInitialResidual() will have nonzero guess */ } ksp->guess_zero = guess_zero; /* restore if user provided nonzero initial guess */ 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; ierr = PetscCitationsRegister(SNESCitation,&SNEScite);CHKERRQ(ierr); 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 = PetscObjectSAWsTakeAccess((PetscObject)snes);CHKERRQ(ierr); snes->iter = 0; snes->norm = 0.; ierr = PetscObjectSAWsGrantAccess((PetscObject)snes);CHKERRQ(ierr); if (!snes->vec_func_init_set) { if (fas->eventresidual) {ierr = PetscLogEventBegin(fas->eventresidual,0,0,0,0);CHKERRQ(ierr);} ierr = SNESComputeFunction(snes,X,F);CHKERRQ(ierr); if (fas->eventresidual) {ierr = PetscLogEventEnd(fas->eventresidual,0,0,0,0);CHKERRQ(ierr);} if (snes->domainerror) { snes->reason = SNES_DIVERGED_FUNCTION_DOMAIN; PetscFunctionReturn(0); } } else snes->vec_func_init_set = PETSC_FALSE; ierr = VecNorm(F, NORM_2, &fnorm);CHKERRQ(ierr); /* fnorm <- ||F|| */ if (PetscIsInfOrNanReal(fnorm)) { snes->reason = SNES_DIVERGED_FNORM_NAN; PetscFunctionReturn(0); } 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 (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 if (fas->fastype == SNES_FAS_ADDITIVE) { ierr = SNESFASCycle_Additive(snes, X);CHKERRQ(ierr); } else if (fas->fastype == SNES_FAS_FULL) { ierr = SNESFASCycle_Full(snes, X);CHKERRQ(ierr); } else if (fas->fastype ==SNES_FAS_KASKADE) { ierr = SNESFASCycle_Kaskade(snes, X);CHKERRQ(ierr); } else { SETERRQ(PetscObjectComm((PetscObject)snes),PETSC_ERR_ARG_WRONGSTATE,"Unsupported FAS type"); } /* check for FAS cycle divergence */ if (snes->reason != SNES_CONVERGED_ITERATING) PetscFunctionReturn(0); /* Monitor convergence */ ierr = PetscObjectSAWsTakeAccess((PetscObject)snes);CHKERRQ(ierr); snes->iter = i+1; 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 */ 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); }
static PetscErrorCode KSPSolve_PIPEFCG(KSP ksp) { PetscErrorCode ierr; KSP_PIPEFCG *pipefcg; PetscScalar gamma; PetscReal dp=0.0; Vec B,R,Z,X; Mat Amat,Pmat; #define VecXDot(x,y,a) (((pipefcg->type) == (KSP_CG_HERMITIAN)) ? VecDot (x,y,a) : VecTDot (x,y,a)) PetscFunctionBegin; ierr = PetscCitationsRegister(citation,&cited);CHKERRQ(ierr); pipefcg = (KSP_PIPEFCG*)ksp->data; X = ksp->vec_sol; B = ksp->vec_rhs; R = ksp->work[0]; Z = ksp->work[1]; ierr = PCGetOperators(ksp->pc,&Amat,&Pmat);CHKERRQ(ierr); /* Compute initial residual needed for convergence check*/ ksp->its = 0; if (!ksp->guess_zero) { ierr = KSP_MatMult(ksp,Amat,X,R);CHKERRQ(ierr); ierr = VecAYPX(R,-1.0,B);CHKERRQ(ierr); /* r <- b - Ax */ } else { ierr = VecCopy(B,R);CHKERRQ(ierr); /* r <- b (x is 0) */ } switch (ksp->normtype) { case KSP_NORM_PRECONDITIONED: ierr = KSP_PCApply(ksp,R,Z);CHKERRQ(ierr); /* z <- Br */ ierr = VecNorm(Z,NORM_2,&dp);CHKERRQ(ierr); /* dp <- dqrt(z'*z) = sqrt(e'*A'*B'*B*A*e) */ break; case KSP_NORM_UNPRECONDITIONED: ierr = VecNorm(R,NORM_2,&dp);CHKERRQ(ierr); /* dp <- sqrt(r'*r) = sqrt(e'*A'*A*e) */ break; case KSP_NORM_NATURAL: ierr = KSP_PCApply(ksp,R,Z);CHKERRQ(ierr); /* z <- Br */ ierr = VecXDot(Z,R,&gamma);CHKERRQ(ierr); dp = PetscSqrtReal(PetscAbsScalar(gamma)); /* dp <- sqrt(r'*z) = sqrt(e'*A'*B*A*e) */ break; case KSP_NORM_NONE: dp = 0.0; break; default: SETERRQ1(PetscObjectComm((PetscObject)ksp),PETSC_ERR_SUP,"%s",KSPNormTypes[ksp->normtype]); } /* Initial Convergence Check */ ierr = KSPLogResidualHistory(ksp,dp);CHKERRQ(ierr); ierr = KSPMonitor(ksp,0,dp);CHKERRQ(ierr); ksp->rnorm = dp; if (ksp->normtype == KSP_NORM_NONE) { ierr = KSPConvergedSkip (ksp,0,dp,&ksp->reason,ksp->cnvP);CHKERRQ(ierr); } else { ierr = (*ksp->converged)(ksp,0,dp,&ksp->reason,ksp->cnvP);CHKERRQ(ierr); } if (ksp->reason) PetscFunctionReturn(0); do { /* A cycle is broken only if a norm breakdown occurs. If not the entire solve happens in a single cycle. This is coded this way to allow both truncation and truncation-restart strategy (see KSPFCDGetNumOldDirections()) */ ierr = KSPSolve_PIPEFCG_cycle(ksp);CHKERRQ(ierr); if (ksp->reason) break; if (pipefcg->norm_breakdown) { pipefcg->n_restarts++; pipefcg->norm_breakdown = PETSC_FALSE; } } while (ksp->its < ksp->max_it); if (ksp->its >= ksp->max_it) ksp->reason = KSP_DIVERGED_ITS; 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; PetscBool lsSuccess = PETSC_TRUE; SNESLineSearch linesearch; SNESConvergedReason reason; PetscFunctionBegin; 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); if (snes->domainerror) { snes->reason = SNES_DIVERGED_FUNCTION_DOMAIN; PetscFunctionReturn(0); } } else snes->vec_func_init_set = PETSC_FALSE; /* convergence test */ ierr = VecNorm(F,NORM_2,&fnorm);CHKERRQ(ierr); if (PetscIsInfOrNanReal(fnorm)) { snes->reason = SNES_DIVERGED_FNORM_NAN; PetscFunctionReturn(0); } 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++) { lsSuccess = PETSC_TRUE; /* 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 = 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 = 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); }
PetscErrorCode SNESSolve_Anderson(SNES snes) { SNES_NGMRES *ngmres = (SNES_NGMRES*) snes->data; /* present solution, residual, and preconditioned residual */ Vec X,F,B,D; /* candidate linear combination answers */ Vec XA,FA,XM,FM; /* coefficients and RHS to the minimization problem */ PetscReal fnorm,fMnorm,fAnorm; PetscReal xnorm,ynorm; PetscReal dnorm,dminnorm=0.0,fminnorm; PetscInt restart_count=0; PetscInt k,k_restart,l,ivec; PetscBool selectRestart; SNESConvergedReason reason; PetscErrorCode ierr; 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); /* variable initialization */ snes->reason = SNES_CONVERGED_ITERATING; X = snes->vec_sol; F = snes->vec_func; B = snes->vec_rhs; XA = snes->vec_sol_update; FA = snes->work[0]; D = snes->work[1]; /* work for the line search */ XM = snes->work[3]; FM = snes->work[4]; ierr = PetscObjectSAWsTakeAccess((PetscObject)snes);CHKERRQ(ierr); snes->iter = 0; snes->norm = 0.; ierr = PetscObjectSAWsGrantAccess((PetscObject)snes);CHKERRQ(ierr); /* initialization */ /* r = F(x) */ if (snes->pc && snes->pcside == PC_LEFT) { 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); } fminnorm = 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); ierr = (*snes->ops->converged)(snes,0,0.0,0.0,fnorm,&snes->reason,snes->cnvP);CHKERRQ(ierr); if (snes->reason) PetscFunctionReturn(0); k_restart = 0; l = 0; ivec = 0; for (k=1; k < snes->max_its+1; k++) { /* select which vector of the stored subspace will be updated */ if (snes->pc && snes->pcside == PC_RIGHT) { ierr = VecCopy(X,XM);CHKERRQ(ierr); ierr = SNESSetInitialFunction(snes->pc,F);CHKERRQ(ierr); ierr = PetscLogEventBegin(SNES_NPCSolve,snes->pc,XM,B,0);CHKERRQ(ierr); ierr = SNESSolve(snes->pc,B,XM);CHKERRQ(ierr); ierr = PetscLogEventEnd(SNES_NPCSolve,snes->pc,XM,B,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,FM,&fMnorm);CHKERRQ(ierr); if (ngmres->andersonBeta != 1.0) { VecAXPBY(XM,(1.0 - ngmres->andersonBeta),ngmres->andersonBeta,X);CHKERRQ(ierr); } } else { ierr = VecCopy(F,FM);CHKERRQ(ierr); ierr = VecCopy(X,XM);CHKERRQ(ierr); ierr = VecAXPY(XM,-ngmres->andersonBeta,FM);CHKERRQ(ierr); fMnorm = fnorm; } ierr = SNESNGMRESFormCombinedSolution_Private(snes,ivec,l,XM,FM,fMnorm,X,XA,FA);CHKERRQ(ierr); ivec = k_restart % ngmres->msize; if (ngmres->restart_type == SNES_NGMRES_RESTART_DIFFERENCE) { ierr = SNESNGMRESNorms_Private(snes,l,X,F,XM,FM,XA,FA,D,&dnorm,&dminnorm,NULL,NULL,NULL,&xnorm,&fAnorm,&ynorm);CHKERRQ(ierr); ierr = SNESNGMRESSelectRestart_Private(snes,l,fMnorm,fnorm,dnorm,fminnorm,dminnorm,&selectRestart);CHKERRQ(ierr); /* if the restart conditions persist for more than restart_it iterations, restart. */ if (selectRestart) restart_count++; else restart_count = 0; } else if (ngmres->restart_type == SNES_NGMRES_RESTART_PERIODIC) { ierr = SNESNGMRESNorms_Private(snes,l,X,F,XM,FM,XA,FA,D,NULL,NULL,NULL,NULL,NULL,&xnorm,&fAnorm,&ynorm);CHKERRQ(ierr); if (k_restart > ngmres->restart_periodic) { if (ngmres->monitor) ierr = PetscViewerASCIIPrintf(ngmres->monitor,"periodic restart after %D iterations\n",k_restart);CHKERRQ(ierr); restart_count = ngmres->restart_it; } } else { ierr = SNESNGMRESNorms_Private(snes,l,X,F,XM,FM,XA,FA,D,NULL,NULL,NULL,NULL,NULL,&xnorm,&fAnorm,&ynorm);CHKERRQ(ierr); } /* restart after restart conditions have persisted for a fixed number of iterations */ if (restart_count >= ngmres->restart_it) { if (ngmres->monitor) { ierr = PetscViewerASCIIPrintf(ngmres->monitor,"Restarted at iteration %d\n",k_restart);CHKERRQ(ierr); } restart_count = 0; k_restart = 0; l = 0; ivec = 0; } else { if (l < ngmres->msize) l++; k_restart++; ierr = SNESNGMRESUpdateSubspace_Private(snes,ivec,l,FM,fnorm,XM);CHKERRQ(ierr); } fnorm = fAnorm; if (fminnorm > fnorm) fminnorm = fnorm; ierr = VecCopy(XA,X);CHKERRQ(ierr); ierr = VecCopy(FA,F);CHKERRQ(ierr); ierr = PetscObjectSAWsTakeAccess((PetscObject)snes);CHKERRQ(ierr); snes->iter = k; snes->norm = fnorm; ierr = PetscObjectSAWsGrantAccess((PetscObject)snes);CHKERRQ(ierr); ierr = SNESLogConvergenceHistory(snes,snes->norm,snes->iter);CHKERRQ(ierr); ierr = SNESMonitor(snes,snes->iter,snes->norm);CHKERRQ(ierr); ierr = (*snes->ops->converged)(snes,snes->iter,xnorm,ynorm,fnorm,&snes->reason,snes->cnvP);CHKERRQ(ierr); if (snes->reason) PetscFunctionReturn(0); } snes->reason = SNES_DIVERGED_MAX_IT; PetscFunctionReturn(0); }
static PetscErrorCode SNESSolve_MS(SNES snes) { SNES_MS *ms = (SNES_MS*)snes->data; Vec X = snes->vec_sol,F = snes->vec_func; PetscReal fnorm; PetscInt i; PetscErrorCode ierr; PetscFunctionBegin; ierr = PetscCitationsRegister(SNESCitation,&SNEScite);CHKERRQ(ierr); 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->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);CHKERRQ(ierr); } if (ms->norms) { ierr = VecNorm(F,NORM_2,&fnorm);CHKERRQ(ierr); /* fnorm <- ||F|| */ if (PetscIsInfOrNanReal(fnorm)) { snes->reason = SNES_DIVERGED_FNORM_NAN; PetscFunctionReturn(0); } /* Monitor convergence */ ierr = PetscObjectSAWsTakeAccess((PetscObject)snes);CHKERRQ(ierr); snes->iter = 0; 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,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)) { snes->reason = SNES_DIVERGED_FNORM_NAN; PetscFunctionReturn(0); } /* 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,0);CHKERRQ(ierr); 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); }
static PetscErrorCode SNESSolve_MS(SNES snes) { SNES_MS *ms = (SNES_MS*)snes->data; Vec X = snes->vec_sol,F = snes->vec_func; PetscReal fnorm; PetscInt i; PetscErrorCode ierr; 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; ierr = PetscObjectSAWsTakeAccess((PetscObject)snes);CHKERRQ(ierr); snes->iter = 0; snes->norm = 0.; ierr = PetscObjectSAWsGrantAccess((PetscObject)snes);CHKERRQ(ierr); if (!snes->vec_func_init_set) { ierr = SNESComputeFunction(snes,X,F);CHKERRQ(ierr); } 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);CHKERRQ(ierr); } if (ms->norms) { ierr = VecNorm(F,NORM_2,&fnorm);CHKERRQ(ierr); /* fnorm <- ||F|| */ SNESCheckFunctionNorm(snes,fnorm); /* Monitor convergence */ ierr = PetscObjectSAWsTakeAccess((PetscObject)snes);CHKERRQ(ierr); snes->iter = 0; 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,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 (ms->norms) { ierr = VecNorm(F,NORM_2,&fnorm);CHKERRQ(ierr); /* fnorm <- ||F|| */ SNESCheckFunctionNorm(snes,fnorm); /* 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,0);CHKERRQ(ierr); 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); }
static PetscErrorCode TSStep_Alpha(TS ts) { TS_Alpha *th = (TS_Alpha*)ts->data; PetscInt rejections = 0; PetscBool stageok,accept = PETSC_TRUE; PetscReal next_time_step = ts->time_step; PetscErrorCode ierr; PetscFunctionBegin; ierr = PetscCitationsRegister(citation,&cited);CHKERRQ(ierr); if (!ts->steprollback) { if (th->adapt) { ierr = VecCopy(th->X0,th->vec_sol_prev);CHKERRQ(ierr); } if (th->adapt) { ierr = VecCopy(th->V0,th->vec_dot_prev);CHKERRQ(ierr); } ierr = VecCopy(ts->vec_sol,th->X0);CHKERRQ(ierr); ierr = VecCopy(ts->vec_dot,th->V0);CHKERRQ(ierr); ierr = VecCopy(th->A1,th->A0);CHKERRQ(ierr); } th->status = TS_STEP_INCOMPLETE; while (!ts->reason && th->status != TS_STEP_COMPLETE) { if (ts->steprestart) { ierr = TSAlpha_Restart(ts,&stageok);CHKERRQ(ierr); if (!stageok) goto reject_step; } ierr = TSAlpha_StageTime(ts);CHKERRQ(ierr); ierr = VecCopy(th->X0,th->X1);CHKERRQ(ierr); ierr = TSPreStage(ts,th->stage_time);CHKERRQ(ierr); ierr = TS_SNESSolve(ts,NULL,th->X1);CHKERRQ(ierr); ierr = TSPostStage(ts,th->stage_time,0,&th->Xa);CHKERRQ(ierr); ierr = TSAdaptCheckStage(ts->adapt,ts,th->stage_time,th->Xa,&stageok);CHKERRQ(ierr); if (!stageok) goto reject_step; th->status = TS_STEP_PENDING; ierr = VecCopy(th->X1,ts->vec_sol);CHKERRQ(ierr); ierr = VecCopy(th->V1,ts->vec_dot);CHKERRQ(ierr); ierr = TSAdaptChoose(ts->adapt,ts,ts->time_step,NULL,&next_time_step,&accept);CHKERRQ(ierr); th->status = accept ? TS_STEP_COMPLETE : TS_STEP_INCOMPLETE; if (!accept) { ierr = VecCopy(th->X0,ts->vec_sol);CHKERRQ(ierr); ierr = VecCopy(th->V0,ts->vec_dot);CHKERRQ(ierr); ts->time_step = next_time_step; goto reject_step; } ts->ptime += ts->time_step; ts->time_step = next_time_step; break; reject_step: ts->reject++; accept = PETSC_FALSE; if (!ts->reason && ++rejections > ts->max_reject && ts->max_reject >= 0) { ts->reason = TS_DIVERGED_STEP_REJECTED; ierr = PetscInfo2(ts,"Step=%D, step rejections %D greater than current TS allowed, stopping solve\n",ts->steps,rejections);CHKERRQ(ierr); } } 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 SNESSolve_NGS(SNES snes) { Vec F; Vec X; Vec B; PetscInt i; PetscReal fnorm; PetscErrorCode ierr; SNESNormSchedule normschedule; PetscFunctionBegin; ierr = PetscCitationsRegister(SNESCitation,&SNEScite);CHKERRQ(ierr); X = snes->vec_sol; F = snes->vec_func; B = snes->vec_rhs; ierr = PetscObjectSAWsTakeAccess((PetscObject)snes);CHKERRQ(ierr); snes->iter = 0; snes->norm = 0.; ierr = PetscObjectSAWsGrantAccess((PetscObject)snes);CHKERRQ(ierr); snes->reason = SNES_CONVERGED_ITERATING; ierr = SNESGetNormSchedule(snes, &normschedule);CHKERRQ(ierr); if (normschedule == SNES_NORM_ALWAYS || normschedule == SNES_NORM_INITIAL_ONLY || normschedule == SNES_NORM_INITIAL_FINAL_ONLY) { /* compute the initial function and preconditioned update delX */ 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; ierr = VecNorm(F, NORM_2, &fnorm);CHKERRQ(ierr); /* fnorm <- ||F|| */ if (PetscIsInfOrNanReal(fnorm)) { snes->reason = SNES_DIVERGED_FNORM_NAN; PetscFunctionReturn(0); } ierr = PetscObjectSAWsTakeAccess((PetscObject)snes);CHKERRQ(ierr); snes->iter = 0; snes->norm = fnorm; ierr = PetscObjectSAWsGrantAccess((PetscObject)snes);CHKERRQ(ierr); ierr = SNESLogConvergenceHistory(snes,snes->norm,0);CHKERRQ(ierr); ierr = SNESMonitor(snes,0,snes->norm);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); } else { ierr = PetscObjectSAWsGrantAccess((PetscObject)snes);CHKERRQ(ierr); ierr = SNESLogConvergenceHistory(snes,snes->norm,0);CHKERRQ(ierr); ierr = SNESMonitor(snes,0,snes->norm);CHKERRQ(ierr); } /* 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 = SNESComputeNGS(snes, B, X);CHKERRQ(ierr); /* only compute norms if requested or about to exit due to maximum iterations */ if (normschedule == SNES_NORM_ALWAYS || ((i == snes->max_its - 1) && (normschedule == SNES_NORM_INITIAL_FINAL_ONLY || normschedule == SNES_NORM_FINAL_ONLY))) { ierr = SNESComputeFunction(snes,X,F);CHKERRQ(ierr); if (snes->domainerror) { snes->reason = SNES_DIVERGED_FUNCTION_DOMAIN; PetscFunctionReturn(0); } ierr = VecNorm(F, NORM_2, &fnorm);CHKERRQ(ierr); /* fnorm <- ||F|| */ if (PetscIsInfOrNanReal(fnorm)) { snes->reason = SNES_DIVERGED_FNORM_NAN; PetscFunctionReturn(0); } } /* 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,0);CHKERRQ(ierr); ierr = SNESMonitor(snes,snes->iter,snes->norm);CHKERRQ(ierr); /* Test for convergence */ if (normschedule == SNES_NORM_ALWAYS) 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 (normschedule == SNES_NORM_ALWAYS) { 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; } } else if (!snes->reason) snes->reason = SNES_CONVERGED_ITS; /* GS is meant to be used as a preconditioner */ PetscFunctionReturn(0); }
PetscErrorCode MatSolve_SuperLU_DIST(Mat A,Vec b_mpi,Vec x) { Mat_SuperLU_DIST *lu = (Mat_SuperLU_DIST*)A->spptr; PetscErrorCode ierr; PetscMPIInt size; PetscInt m=A->rmap->n,M=A->rmap->N,N=A->cmap->N; SuperLUStat_t stat; double berr[1]; PetscScalar *bptr; PetscInt nrhs=1; Vec x_seq; IS iden; VecScatter scat; int info; /* SuperLU_Dist info code is ALWAYS an int, even with long long indices */ static PetscBool cite = PETSC_FALSE; PetscFunctionBegin; ierr = PetscCitationsRegister("@article{lidemmel03,\n author = {Xiaoye S. Li and James W. Demmel},\n title = {{SuperLU_DIST}: A Scalable Distributed-Memory Sparse Direct\n Solver for Unsymmetric Linear Systems},\n journal = {ACM Trans. Mathematical Software},\n volume = {29},\n number = {2},\n pages = {110-140},\n year = 2003\n}\n",&cite);CHKERRQ(ierr); ierr = MPI_Comm_size(PetscObjectComm((PetscObject)A),&size);CHKERRQ(ierr); if (size > 1 && lu->MatInputMode == GLOBAL) { /* global mat input, convert b to x_seq */ ierr = VecCreateSeq(PETSC_COMM_SELF,N,&x_seq);CHKERRQ(ierr); ierr = ISCreateStride(PETSC_COMM_SELF,N,0,1,&iden);CHKERRQ(ierr); ierr = VecScatterCreate(b_mpi,iden,x_seq,iden,&scat);CHKERRQ(ierr); ierr = ISDestroy(&iden);CHKERRQ(ierr); ierr = VecScatterBegin(scat,b_mpi,x_seq,INSERT_VALUES,SCATTER_FORWARD);CHKERRQ(ierr); ierr = VecScatterEnd(scat,b_mpi,x_seq,INSERT_VALUES,SCATTER_FORWARD);CHKERRQ(ierr); ierr = VecGetArray(x_seq,&bptr);CHKERRQ(ierr); } else { /* size==1 || distributed mat input */ if (lu->options.SolveInitialized && !lu->matsolve_iscalled) { /* see comments in MatMatSolve() */ #if defined(PETSC_USE_COMPLEX) PetscStackCall("SuperLU_DIST:zSolveFinalize",zSolveFinalize(&lu->options, &lu->SOLVEstruct)); #else PetscStackCall("SuperLU_DIST:dSolveFinalize",dSolveFinalize(&lu->options, &lu->SOLVEstruct)); #endif lu->options.SolveInitialized = NO; } ierr = VecCopy(b_mpi,x);CHKERRQ(ierr); ierr = VecGetArray(x,&bptr);CHKERRQ(ierr); } if (lu->options.Fact != FACTORED) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_WRONG,"SuperLU_DIST options.Fact mush equal FACTORED"); PetscStackCall("SuperLU_DIST:PStatInit",PStatInit(&stat)); /* Initialize the statistics variables. */ if (lu->MatInputMode == GLOBAL) { #if defined(PETSC_USE_COMPLEX) PetscStackCall("SuperLU_DIST:pzgssvx_ABglobal",pzgssvx_ABglobal(&lu->options,&lu->A_sup,&lu->ScalePermstruct,(doublecomplex*)bptr,M,nrhs,&lu->grid,&lu->LUstruct,berr,&stat,&info)); #else PetscStackCall("SuperLU_DIST:pdgssvx_ABglobal",pdgssvx_ABglobal(&lu->options, &lu->A_sup, &lu->ScalePermstruct,bptr,M,nrhs,&lu->grid,&lu->LUstruct,berr,&stat,&info)); #endif } else { /* distributed mat input */ #if defined(PETSC_USE_COMPLEX) PetscStackCall("SuperLU_DIST:pzgssvx",pzgssvx(&lu->options,&lu->A_sup,&lu->ScalePermstruct,(doublecomplex*)bptr,m,nrhs,&lu->grid,&lu->LUstruct,&lu->SOLVEstruct,berr,&stat,&info)); #else PetscStackCall("SuperLU_DIST:pdgssvx",pdgssvx(&lu->options,&lu->A_sup,&lu->ScalePermstruct,bptr,m,nrhs,&lu->grid,&lu->LUstruct,&lu->SOLVEstruct,berr,&stat,&info)); #endif } if (info) SETERRQ1(PETSC_COMM_SELF,PETSC_ERR_LIB,"pdgssvx fails, info: %d\n",info); if (lu->options.PrintStat) PStatPrint(&lu->options, &stat, &lu->grid); /* Print the statistics. */ PetscStackCall("SuperLU_DIST:PStatFree",PStatFree(&stat)); if (size > 1 && lu->MatInputMode == GLOBAL) { /* convert seq x to mpi x */ ierr = VecRestoreArray(x_seq,&bptr);CHKERRQ(ierr); ierr = VecScatterBegin(scat,x_seq,x,INSERT_VALUES,SCATTER_REVERSE);CHKERRQ(ierr); ierr = VecScatterEnd(scat,x_seq,x,INSERT_VALUES,SCATTER_REVERSE);CHKERRQ(ierr); ierr = VecScatterDestroy(&scat);CHKERRQ(ierr); ierr = VecDestroy(&x_seq);CHKERRQ(ierr); } else { ierr = VecRestoreArray(x,&bptr);CHKERRQ(ierr); lu->matsolve_iscalled = PETSC_TRUE; lu->matmatsolve_iscalled = PETSC_FALSE; } PetscFunctionReturn(0); }
static PetscErrorCode SNESLineSearchApply_NLEQERR(SNESLineSearch linesearch) { PetscBool changed_y,changed_w; PetscErrorCode ierr; Vec X,F,Y,W,G; SNES snes; PetscReal fnorm, xnorm, ynorm, gnorm, wnorm; PetscReal lambda, minlambda, stol; PetscViewer monitor; PetscInt max_its, count, snes_iteration; PetscReal theta, mudash, lambdadash; SNESLineSearch_NLEQERR *nleqerr = (SNESLineSearch_NLEQERR*)linesearch->data; KSPConvergedReason kspreason; PetscFunctionBegin; ierr = PetscCitationsRegister(NLEQERR_citation, &NLEQERR_cited);CHKERRQ(ierr); ierr = SNESLineSearchGetVecs(linesearch, &X, &F, &Y, &W, &G);CHKERRQ(ierr); ierr = SNESLineSearchGetNorms(linesearch, &xnorm, &fnorm, &ynorm);CHKERRQ(ierr); ierr = SNESLineSearchGetLambda(linesearch, &lambda);CHKERRQ(ierr); ierr = SNESLineSearchGetSNES(linesearch, &snes);CHKERRQ(ierr); ierr = SNESLineSearchGetDefaultMonitor(linesearch, &monitor);CHKERRQ(ierr); ierr = SNESLineSearchGetTolerances(linesearch,&minlambda,NULL,NULL,NULL,NULL,&max_its);CHKERRQ(ierr); ierr = SNESGetTolerances(snes,NULL,NULL,&stol,NULL,NULL);CHKERRQ(ierr); /* reset the state of the Lipschitz estimates */ ierr = SNESGetIterationNumber(snes, &snes_iteration);CHKERRQ(ierr); if (!snes_iteration) { ierr = SNESLineSearchReset_NLEQERR(linesearch);CHKERRQ(ierr); } /* precheck */ ierr = SNESLineSearchPreCheck(linesearch,X,Y,&changed_y);CHKERRQ(ierr); ierr = SNESLineSearchSetReason(linesearch, SNES_LINESEARCH_SUCCEEDED);CHKERRQ(ierr); ierr = VecNormBegin(Y, NORM_2, &ynorm);CHKERRQ(ierr); ierr = VecNormBegin(X, NORM_2, &xnorm);CHKERRQ(ierr); ierr = VecNormEnd(Y, NORM_2, &ynorm);CHKERRQ(ierr); ierr = VecNormEnd(X, NORM_2, &xnorm);CHKERRQ(ierr); /* Note: Y is *minus* the Newton step. For whatever reason PETSc doesn't solve with the minus on the RHS. */ if (ynorm == 0.0) { if (monitor) { ierr = PetscViewerASCIIAddTab(monitor,((PetscObject)linesearch)->tablevel);CHKERRQ(ierr); ierr = PetscViewerASCIIPrintf(monitor," Line search: Initial direction and size is 0\n");CHKERRQ(ierr); ierr = PetscViewerASCIISubtractTab(monitor,((PetscObject)linesearch)->tablevel);CHKERRQ(ierr); } ierr = VecCopy(X,W);CHKERRQ(ierr); ierr = VecCopy(F,G);CHKERRQ(ierr); ierr = SNESLineSearchSetNorms(linesearch,xnorm,fnorm,ynorm);CHKERRQ(ierr); ierr = SNESLineSearchSetReason(linesearch, SNES_LINESEARCH_FAILED_REDUCT);CHKERRQ(ierr); PetscFunctionReturn(0); } /* At this point, we've solved the Newton system for delta_x, and we assume that its norm is greater than the solution tolerance (otherwise we wouldn't be in here). So let's go ahead and estimate the Lipschitz constant. W contains bar_delta_x_prev at this point. */ if (monitor) { ierr = PetscViewerASCIIAddTab(monitor,((PetscObject)linesearch)->tablevel);CHKERRQ(ierr); ierr = PetscViewerASCIIPrintf(monitor," Line search: norm of Newton step: %14.12e\n", (double) ynorm);CHKERRQ(ierr); ierr = PetscViewerASCIISubtractTab(monitor,((PetscObject)linesearch)->tablevel);CHKERRQ(ierr); } /* this needs information from a previous iteration, so can't do it on the first one */ if (nleqerr->norm_delta_x_prev > 0 && nleqerr->norm_bar_delta_x_prev > 0) { ierr = VecWAXPY(G, +1.0, Y, W);CHKERRQ(ierr); /* bar_delta_x - delta_x; +1 because Y is -delta_x */ ierr = VecNormBegin(G, NORM_2, &gnorm);CHKERRQ(ierr); ierr = VecNormEnd(G, NORM_2, &gnorm);CHKERRQ(ierr); nleqerr->mu_curr = nleqerr->lambda_prev * (nleqerr->norm_delta_x_prev * nleqerr->norm_bar_delta_x_prev) / (gnorm * ynorm); lambda = PetscMin(1.0, nleqerr->mu_curr); if (monitor) { ierr = PetscViewerASCIIAddTab(monitor,((PetscObject)linesearch)->tablevel);CHKERRQ(ierr); ierr = PetscViewerASCIIPrintf(monitor," Line search: Lipschitz estimate: %14.12e; lambda: %14.12e\n", (double) nleqerr->mu_curr, (double) lambda);CHKERRQ(ierr); ierr = PetscViewerASCIISubtractTab(monitor,((PetscObject)linesearch)->tablevel);CHKERRQ(ierr); } } else { lambda = linesearch->damping; } /* The main while loop of the algorithm. At the end of this while loop, G should have the accepted new X in it. */ count = 0; while (PETSC_TRUE) { if (monitor) { ierr = PetscViewerASCIIAddTab(monitor,((PetscObject)linesearch)->tablevel);CHKERRQ(ierr); ierr = PetscViewerASCIIPrintf(monitor," Line search: entering iteration with lambda: %14.12e\n", lambda);CHKERRQ(ierr); ierr = PetscViewerASCIISubtractTab(monitor,((PetscObject)linesearch)->tablevel);CHKERRQ(ierr); } /* Check that we haven't performed too many iterations */ count += 1; if (count >= max_its) { if (monitor) { ierr = PetscViewerASCIIAddTab(monitor,((PetscObject)linesearch)->tablevel);CHKERRQ(ierr); ierr = PetscViewerASCIIPrintf(monitor," Line search: maximum iterations reached\n");CHKERRQ(ierr); ierr = PetscViewerASCIISubtractTab(monitor,((PetscObject)linesearch)->tablevel);CHKERRQ(ierr); } ierr = SNESLineSearchSetReason(linesearch, SNES_LINESEARCH_FAILED_REDUCT);CHKERRQ(ierr); PetscFunctionReturn(0); } /* Now comes the Regularity Test. */ if (lambda <= minlambda) { /* This isn't what is suggested by Deuflhard, but it works better in my experience */ if (monitor) { ierr = PetscViewerASCIIAddTab(monitor,((PetscObject)linesearch)->tablevel);CHKERRQ(ierr); ierr = PetscViewerASCIIPrintf(monitor," Line search: lambda has reached lambdamin, taking full Newton step\n");CHKERRQ(ierr); ierr = PetscViewerASCIISubtractTab(monitor,((PetscObject)linesearch)->tablevel);CHKERRQ(ierr); } lambda = 1.0; ierr = VecWAXPY(G, -lambda, Y, X);CHKERRQ(ierr); /* and clean up the state for next time */ ierr = SNESLineSearchReset_NLEQERR(linesearch);CHKERRQ(ierr); /* The clang static analyzer detected a problem here; once the loop is broken the values nleqerr->norm_delta_x_prev = ynorm; nleqerr->norm_bar_delta_x_prev = wnorm; are set, but wnorm has not even been computed. I don't know if this is the correct fix but by setting ynorm and wnorm to -1.0 at least the linesearch object is kept in the state set by the SNESLineSearchReset_NLEQERR() call above */ ynorm = wnorm = -1.0; break; } /* Compute new trial iterate */ ierr = VecWAXPY(W, -lambda, Y, X);CHKERRQ(ierr); ierr = SNESComputeFunction(snes, W, G);CHKERRQ(ierr); /* Solve linear system for bar_delta_x_curr: old Jacobian, new RHS. Note absence of minus sign, compared to Deuflhard, in keeping with PETSc convention */ ierr = KSPSolve(snes->ksp, G, W);CHKERRQ(ierr); ierr = KSPGetConvergedReason(snes->ksp, &kspreason);CHKERRQ(ierr); if (kspreason < 0) { ierr = PetscInfo(snes,"Solution for \\bar{delta x}^{k+1} failed.");CHKERRQ(ierr); } /* W now contains -bar_delta_x_curr. */ ierr = VecNorm(W, NORM_2, &wnorm);CHKERRQ(ierr); if (monitor) { ierr = PetscViewerASCIIAddTab(monitor,((PetscObject)linesearch)->tablevel);CHKERRQ(ierr); ierr = PetscViewerASCIIPrintf(monitor," Line search: norm of simplified Newton update: %14.12e\n", (double) wnorm);CHKERRQ(ierr); ierr = PetscViewerASCIISubtractTab(monitor,((PetscObject)linesearch)->tablevel);CHKERRQ(ierr); } /* compute the monitoring quantities theta and mudash. */ theta = wnorm / ynorm; ierr = VecWAXPY(G, -(1.0 - lambda), Y, W);CHKERRQ(ierr); ierr = VecNorm(G, NORM_2, &gnorm);CHKERRQ(ierr); mudash = (0.5 * ynorm * lambda * lambda) / gnorm; /* Check for termination of the linesearch */ if (theta >= 1.0) { /* need to go around again with smaller lambda */ if (monitor) { ierr = PetscViewerASCIIAddTab(monitor,((PetscObject)linesearch)->tablevel);CHKERRQ(ierr); ierr = PetscViewerASCIIPrintf(monitor," Line search: monotonicity check failed, ratio: %14.12e\n", (double) theta);CHKERRQ(ierr); ierr = PetscViewerASCIISubtractTab(monitor,((PetscObject)linesearch)->tablevel);CHKERRQ(ierr); } lambda = PetscMin(mudash, 0.5 * lambda); lambda = PetscMax(lambda, minlambda); /* continue through the loop, i.e. go back to regularity test */ } else { /* linesearch terminated */ lambdadash = PetscMin(1.0, mudash); if (lambdadash == 1.0 && lambda == 1.0 && wnorm <= stol) { /* store the updated state, X - Y - W, in G: I need to keep W for the next linesearch */ ierr = VecCopy(X, G);CHKERRQ(ierr); ierr = VecAXPY(G, -1.0, Y);CHKERRQ(ierr); ierr = VecAXPY(G, -1.0, W);CHKERRQ(ierr); break; } /* Deuflhard suggests to add the following: else if (lambdadash >= 4.0 * lambda) { lambda = lambdadash; } to continue through the loop, i.e. go back to regularity test. I deliberately exclude this, as I have practical experience of this getting stuck in infinite loops (on e.g. an Allen--Cahn problem). */ else { /* accept iterate without adding on, i.e. don't use bar_delta_x; again, I need to keep W for the next linesearch */ ierr = VecWAXPY(G, -lambda, Y, X);CHKERRQ(ierr); break; } } } if (linesearch->ops->viproject) { ierr = (*linesearch->ops->viproject)(snes, G);CHKERRQ(ierr); } /* W currently contains -bar_delta_u. Scale it so that it contains bar_delta_u. */ ierr = VecScale(W, -1.0);CHKERRQ(ierr); /* postcheck */ ierr = SNESLineSearchPostCheck(linesearch,X,Y,G,&changed_y,&changed_w);CHKERRQ(ierr); if (changed_y || changed_w) { ierr = SNESLineSearchSetReason(linesearch, SNES_LINESEARCH_FAILED_USER);CHKERRQ(ierr); ierr = PetscInfo(snes,"Changing the search direction here doesn't make sense.\n");CHKERRQ(ierr); PetscFunctionReturn(0); } /* copy the solution and information from this iteration over */ nleqerr->norm_delta_x_prev = ynorm; nleqerr->norm_bar_delta_x_prev = wnorm; nleqerr->lambda_prev = lambda; ierr = VecCopy(G, X);CHKERRQ(ierr); ierr = SNESComputeFunction(snes, X, F);CHKERRQ(ierr); ierr = VecNorm(X, NORM_2, &xnorm);CHKERRQ(ierr); ierr = VecNorm(F, NORM_2, &fnorm);CHKERRQ(ierr); ierr = SNESLineSearchSetLambda(linesearch, lambda);CHKERRQ(ierr); ierr = SNESLineSearchSetNorms(linesearch, xnorm, fnorm, (ynorm < 0 ? PETSC_INFINITY : ynorm));CHKERRQ(ierr); PetscFunctionReturn(0); }