# TaoBRGNSetRegularizerObjectiveAndGradientRoutine
Sets the user-defined regularizer call-back function into the algorithm. 
## Synopsis
```
#include "petsctao.h" 
PetscErrorCode TaoBRGNSetRegularizerObjectiveAndGradientRoutine(Tao tao, PetscErrorCode (*func)(Tao, Vec, PetscReal *, Vec, void *), void *ctx)
```

## Input Parameters

- ***tao -*** the Tao context
- ***func -*** function pointer for the regularizer value and gradient evaluation
- ***ctx -*** user context for the regularizer




## Level
advanced

## Location
<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/tao/leastsquares/impls/brgn/brgn.c.html#TaoBRGNSetRegularizerObjectiveAndGradientRoutine">src/tao/leastsquares/impls/brgn/brgn.c</A>

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


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[Edit on GitLab](https://gitlab.com/petsc/petsc/-/edit/release/src/tao/leastsquares/impls/brgn/brgn.c)


[Index of all Tao routines](index.md)  
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