# TaoGetGradientNorm
Returns the matrix used to define the norm used for measuring the size of the gradient. 
## Synopsis
```
#include "petsctao.h" 
PetscErrorCode TaoGetGradientNorm(Tao tao, Mat *M)
```
Not Collective


## Input Parameter

- ***tao  -*** Tao context



## Output Parameter

- ***M -*** gradient norm





## See Also
 `Tao`, `TaoSetGradientNorm()`, `TaoGradientNorm()`

## Level
beginner

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


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


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