SNESSetTolerances

Sets SNES various parameters used in convergence tests.

Synopsis

#include "petscsnes.h"  
PetscErrorCode SNESSetTolerances(SNES snes, PetscReal abstol, PetscReal rtol, PetscReal stol, PetscInt maxit, PetscInt maxf)

Logically Collective

Input Parameters

• snes - the SNES context

• abstol - absolute convergence tolerance

• rtol - relative convergence tolerance

• stol - convergence tolerance in terms of the norm of the change in the solution between steps, || delta x || < stol*|| x ||

• maxit - maximum number of iterations, default 50.

• maxf - maximum number of function evaluations (use PETSC_UNLIMITED indicates no limit), default 10,000

Options Database Keys

• -snes_atol - Sets abstol

• -snes_rtol - Sets rtol

• -snes_stol - Sets stol

• -snes_max_it - Sets maxit

• -snes_max_funcs - Sets maxf (use unlimited to have no maximum)

Note

All parameters must be non-negative

Use PETSC_CURRENT to retain the current value of any parameter and PETSC_DETERMINE to use the default value for the given SNES. The default value is the value in the object when its type is set.

Use PETSC_UNLIMITED on maxit or maxf to indicate there is no bound on the number of iterations or number of function evaluations.

Fortran Note

Use PETSC_CURRENT_INTEGER, PETSC_CURRENT_REAL, PETSC_UNLIMITED_INTEGER, PETSC_DETERMINE_INTEGER, or PETSC_DETERMINE_REAL

See Also

SNES: Nonlinear Solvers, SNESSolve(), SNES, SNESSetDivergenceTolerance(), SNESSetForceIteration()

Level

intermediate

Location

src/snes/interface/snes.c

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