SNESCheckFunctionDomainError#

Called after a SNESComputeFunction() and VecNorm() in a SNES solver to check if the function norm is infinity or NaN and if the function callback set with SNESSetFunction() called SNESSetFunctionDomainError().

Synopsis#

#include <snesimpl.h>
void SNESCheckFunctionDomainError(SNES snes, PetscReal fnorm)

Collective

Input Parameters#

snes - the SNES solver object
fnorm - the value of the norm

Notes#

If fnorm is infinity or NaN and SNESSetErrorIfNotConverged() was set, this immediately generates a PETSC_ERR_CONV_FAILED.

If fnorm is infinity or NaN and SNESSetFunctionDomainError() was called, this sets the SNESConvergedReason to SNES_DIVERGED_FUNCTION_DOMAIN and exits the solver

Otherwise if fnorm is infinity or NaN, this sets the SNESConvergedReason to SNES_DIVERGED_FUNCTION_NANORINF and exits the solver

Developer Note#

This function exists so that SNESSetFunctionDomainError() does not need to be a collective operation since making it collective would be cumbersome in most applications and require extra communication. Instead, SNESSetFunctionDomainError() sets the functiondomainerror flag in the SNES object to true, SNESComputeFunction() checks that flag and sets a NaN into its local part of the vector if the flag has been set. Then, when VecNorm() is called on the vector containing the computed function value, any NaN is propagated to all MPI processes without any additional communication. Virtually all nonlinear solvers need to compute the function norm at some point so no extra communication needs to take place.

Synopsis#

#include <snesimpl.h>
void SNESCheckObjectiveDomainError(SNES snes, PetscReal fobj)

Collective

Input Parameters#

snes - the SNES solver object
fobj - the value of the objective function

Notes#

If fobj is infinity or NaN and SNESSetErrorIfNotConverged() was set, this immediately generates a PETSC_ERR_CONV_FAILED.

If SNESSetObjectiveDomainError() was called, this sets the SNESConvergedReason to SNES_DIVERGED_OBJECTIVE_DOMAIN and exits the solver

Otherwise if fobj is infinity or NaN, this sets the SNESConvergedReason to SNES_DIVERGED_OBJECTIVE_NANORINF and exits the solver

Synopsis#

#include <snesimpl.h>
void SNESCheckJacobianDomainError(SNES snes)

Collective

Input Parameters#

snes - the SNES solver object

Notes#

This turns the non-collective SNESSetJacobianDomainError() into a collective operation

This check is done in debug mode or if SNESSetCheckJacobianDomainError() has been called

Synopsis#

#include <snesimpl.h>
void SNESCheckLineSearchFailure(SNES snes)

Collective

Input Parameters#

snes - the SNES solver object

Notes#

If SNESLineSearchApply() produces a SNES_LINESEARCH_FAILED_NANORINF or SNES_LINESEARCH_FAILED_NANORINF the SNESSolve() is ended.

If the SNESLineSearchApply() produces any other failure reason and the number of failed steps is greater than the number set with SNESSetMaxNonlinearStepFailures() the SNESSolve() is ended

See Also#

SNES: Nonlinear Solvers, SNESLineSearchApply(), SNESSetFunctionDomainError(), PETSC_ERR_CONV_FAILED, SNESSetErrorIfNotConverged(), SNES_DIVERGED_FUNCTION_DOMAIN, SNESConvergedReason, SNES_DIVERGED_FUNCTION_NAN, SNESSolve(), SNESSetMaxNonlinearStepFailures() MC*/ #define SNESCheckLineSearchFailure(snes)
do {
SNESLineSearchReason lsreason;
PetscCall(SNESLineSearchGetReason(snes->linesearch, &lsreason));
if (lsreason) {
if (lsreason == SNES_LINESEARCH_FAILED_FUNCTION_DOMAIN) {
PetscCheck(!snes->errorifnotconverged, PetscObjectComm((PetscObject)snes), PETSC_ERR_NOT_CONVERGED, “SNESLineSearchApply() has produced failure with function domain”);
snes->reason = SNES_DIVERGED_FUNCTION_DOMAIN;
PetscFunctionReturn(PETSC_SUCCESS);
}
if (lsreason == SNES_LINESEARCH_FAILED_NANORINF) {
PetscCheck(!snes->errorifnotconverged, PetscObjectComm((PetscObject)snes), PETSC_ERR_NOT_CONVERGED, “SNESLineSearchApply() has produced failure with infinity or NaN”);
snes->reason = SNES_DIVERGED_FUNCTION_NANORINF;
PetscFunctionReturn(PETSC_SUCCESS);
}
if (lsreason == SNES_LINESEARCH_FAILED_OBJECTIVE_DOMAIN) {
PetscCheck(!snes->errorifnotconverged, PetscObjectComm((PetscObject)snes), PETSC_ERR_NOT_CONVERGED, “SNESLineSearchApply() has produced failure with objective function domain”);
snes->reason = SNES_DIVERGED_FUNCTION_DOMAIN;
PetscFunctionReturn(PETSC_SUCCESS);
}
if (lsreason == SNES_LINESEARCH_FAILED_JACOBIAN_DOMAIN) {
PetscCheck(!snes->errorifnotconverged, PetscObjectComm((PetscObject)snes), PETSC_ERR_NOT_CONVERGED, “SNESLineSearchApply() has produced failure with Jacobian domain”);
snes->reason = SNES_DIVERGED_JACOBIAN_DOMAIN;
PetscFunctionReturn(PETSC_SUCCESS);
}
if (++snes->numFailures >= snes->maxFailures) {
PetscCheck(!snes->errorifnotconverged, PetscObjectComm((PetscObject)snes), PETSC_ERR_NOT_CONVERGED, “SNESLineSearchApply() has produced failure”);
snes->reason = SNES_DIVERGED_LINE_SEARCH;
PetscFunctionReturn(PETSC_SUCCESS);
}
}
} while (0)

#define SNESCheckKSPSolve(snes)
do {
KSPConvergedReason kspreason;
PetscInt lits;
PetscCall(KSPGetIterationNumber(snes->ksp, &lits));
snes->linear_its += lits;
PetscCall(KSPGetConvergedReason(snes->ksp, &kspreason));
if (kspreason < 0) {
if (kspreason == KSP_DIVERGED_NANORINF) {
PetscBool domainerror;
PetscCallMPI(MPIU_Allreduce(&snes->functiondomainerror, &domainerror, 1, MPI_C_BOOL, MPI_LOR, PetscObjectComm((PetscObject)snes)));
if (domainerror) {
snes->reason = SNES_DIVERGED_FUNCTION_DOMAIN;
snes->functiondomainerror = PETSC_FALSE;
} else snes->reason = SNES_DIVERGED_LINEAR_SOLVE;
PetscFunctionReturn(PETSC_SUCCESS);
} else {
if (++snes->numLinearSolveFailures >= snes->maxLinearSolveFailures) {
PetscCall(PetscInfo(snes, “iter=%” PetscInt_FMT “, number linear solve failures %” PetscInt_FMT “ greater than current SNES allowed %” PetscInt_FMT “, stopping solve\n”, snes->iter, snes->numLinearSolveFailures, snes->maxLinearSolveFailures));
snes->reason = SNES_DIVERGED_LINEAR_SOLVE;
PetscFunctionReturn(PETSC_SUCCESS);
}
}
}
} while (0)

#define SNESNeedNorm_Private(snes, iter)
(((iter) == (snes)->max_its && ((snes)->normschedule == SNES_NORM_FINAL_ONLY || (snes)->normschedule == SNES_NORM_INITIAL_FINAL_ONLY)) || ((iter) == 0 && ((snes)->normschedule == SNES_NORM_INITIAL_ONLY || (snes)->normschedule == SNES_NORM_INITIAL_FINAL_ONLY)) ||
(snes)->normschedule == SNES_NORM_ALWAYS)

Level#

developer

Location#

include/petsc/private/snesimpl.h

Index of all SNES routines
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