# TaoDefaultGMonitor
Default routine for monitoring progress of the Tao solvers (default) with extra detail on the globalization method. This monitor prints the function value and gradient norm at each iteration, as well as the step size and trust radius. Note that the step size and trust radius may be the same for some algorithms. It can be turned on from the command line using the -tao_gmonitor option 
## Synopsis
```
#include "petsctao.h" 
PetscErrorCode TaoDefaultGMonitor(Tao tao, void *ctx)
```
Collective


## Input Parameters

- ***tao -*** the Tao context
- ***ctx -*** `PetscViewer` context or NULL



## Options Database Keys

- ***-tao_gmonitor -*** turn on monitoring with globalization information





## See Also
 `TaoDefaultSMonitor()`, `TaoSetMonitor()`

## Level
advanced

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


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[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)  
