# TaoSetConstraintTolerances
Sets constraint tolerance parameters used in Tao convergence tests 
## Synopsis
```
#include "petsctao.h" 
PetscErrorCode TaoSetConstraintTolerances(Tao tao, PetscReal catol, PetscReal crtol)
```
Logically Collective


## Input Parameters

- ***tao -*** the Tao context
- ***catol -*** absolute constraint tolerance, constraint norm must be less than `catol` for used for gatol convergence criteria
- ***crtol -*** relative constraint tolerance, constraint norm must be less than `crtol` for used for gatol, gttol convergence criteria



## Options Database Keys

- ***-tao_catol <catol> -*** Sets catol
- ***-tao_crtol <crtol> -*** Sets crtol





## Notes
Use `PETSC_DEFAULT` to leave any tolerance unchanged.


## See Also
 `TaoGetTolerances()`, `TaoGetConstraintTolerances()`, `TaoSetTolerances()`

## Level
intermediate

## Location
<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/tao/interface/taosolver.c.html#TaoSetConstraintTolerances">src/tao/interface/taosolver.c</A>

## Examples
<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/tao/constrained/tutorials/ex1.c.html">src/tao/constrained/tutorials/ex1.c.html</A><BR>


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