# SNESSetTrustRegionTolerance
Sets the trust region parameter tolerance. 
## Synopsis
```
#include "petscsnes.h"  
PetscErrorCode SNESSetTrustRegionTolerance(SNES snes, PetscReal tol)
```
Logically Collective on snes


## Input Parameters

- ***snes -*** the `SNES` context
- ***tol -*** tolerance



## Options Database Key

- ***-snes_trtol <tol> -*** Sets tol





## See Also
 `SNES`, `SNESNEWTONTRDC`, `SNESSetTolerances()`

## Level
intermediate

## Location
<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/snes/interface/snes.c.html#SNESSetTrustRegionTolerance">src/snes/interface/snes.c</A>


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[Edit on GitLab](https://gitlab.com/petsc/petsc/-/edit/release/src/snes/interface/snes.c)


[Index of all SNES routines](index.md)  
[Table of Contents for all manual pages](/docs/manualpages/index.md)  
[Index of all manual pages](/docs/manualpages/singleindex.md)  
