SNESSetTolerances#

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 - the absolute convergence tolerance, $F(x^n) \le abstol$

• rtol - the relative convergence tolerance, $F(x^n) \le reltol * F(x^0)$

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

• maxit - the maximum number of iterations allowed in the solver, default 50.

• maxf - the maximum number of function evaluations allowed in the solver (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

Index of all SNES routines
Table of Contents for all manual pages
Index of all manual pages