# SNESSetTolerances

Sets various parameters used in convergence tests.

### Synopsis

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

Collective on SNES

### 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
| maxit | - maximum number of iterations
| maxf | - maximum number of function evaluations

### Options Database Keys

| -snes_atol <abstol> | - Sets abstol
| -snes_rtol <rtol> | - Sets rtol
| -snes_stol <stol> | - Sets stol
| -snes_max_it <maxit> | - Sets maxit
| -snes_max_funcs <maxf> | - Sets maxf

### Notes

The default maximum number of iterations is 50. The default maximum number of function evaluations is 1000.

### Keywords

SNES, nonlinear, set, convergence, tolerances

### See Also

SNESSetTrustRegionTolerance()

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