# PCFactorGetShiftAmount
Gets the tolerance used to define a zero privot
## Synopsis
```
#include "petscpc.h"
PetscErrorCode PCFactorGetShiftAmount(PC pc, PetscReal *shift)
```
Not Collective
## Input Parameters
- ***pc -*** the preconditioner context
## Output Parameter
- ***shift -*** how much to shift the diagonal entry
## See Also
`PCLU`, `PCCHOLESKY`, `PCFactorSetShiftAmount()`, `PCFactorSetShiftType()`, `PCFactorGetShiftType()`
## Level
intermediate
## Location
src/ksp/pc/impls/factor/factor.c
## Implementations
PCFactorGetShiftAmount_Factor in src/ksp/pc/impls/factor/factimpl.c
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[Edit on GitLab](https://gitlab.com/petsc/petsc/-/edit/release/src/ksp/pc/impls/factor/factor.c)
[Index of all PC routines](index.md)
[Table of Contents for all manual pages](/docs/manualpages/index.md)
[Index of all manual pages](/docs/manualpages/singleindex.md)