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


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


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