:orphan:
# SNESNewtonTRDCPreCheck
Called before the step has been determined in `SNESNEWTONTRDC` 
## Synopsis
```
#include "petscsnes.h"   
static PetscErrorCode SNESNewtonTRDCPreCheck(SNES snes, Vec X, Vec Y, PetscBool *changed_Y)
```
Logically Collective


## Input Parameters

- ***snes -*** the solver
- ***X -*** The last solution
- ***Y -*** The step direction



## Output Parameter

- ***changed_Y -*** Indicator that the step direction `Y` has been changed.





## See Also
 `SNESNEWTONTRDC`, `SNESNewtonTRDCSetPreCheck()`, `SNESNewtonTRDCGetPreCheck()`, `SNESNewtonTRDCPostCheck()`

## Level
developer

## Location
<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/snes/impls/ntrdc/ntrdc.c.html#SNESNewtonTRDCPreCheck">src/snes/impls/ntrdc/ntrdc.c</A>


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


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