:orphan:
# PCShellSetApplySymmetricRight
Sets routine to use as right preconditioner (when the `PC_SYMMETRIC` is used).
## Synopsis
```
#include "petscpc.h"
PetscErrorCode PCShellSetApplySymmetricRight(PC pc, PetscErrorCode (*apply)(PC, Vec, Vec))
```
Logically Collective
## Input Parameters
- ***pc -*** the preconditioner context
- ***apply -*** the application-provided right preconditioning routine
## Calling sequence of `apply`
```none
PetscErrorCode apply(PC pc, Vec xin, Vec xout)
```
- ***pc -*** the preconditioner, get the application context with PCShellGetContext()
- ***xin -*** input vector
- ***xout -*** output vector
## See Also
`PCSHELL`, `PCShellSetApply()`, `PCShellSetApplySymmetricLeft()`, `PCShellSetSetUp()`, `PCShellSetApplyTranspose()`, `PCShellSetContext()`
## Level
advanced
## Location
src/ksp/pc/impls/shell/shellpc.c
## Implementations
PCShellSetApplySymmetricRight_Shell(PC pc, PetscErrorCode (*apply) in src/ksp/pc/impls/shell/shellpc.c
---
[Edit on GitLab](https://gitlab.com/petsc/petsc/-/edit/release/src/ksp/pc/impls/shell/shellpc.c)
[Index of all PC routines](index.md)
[Table of Contents for all manual pages](/manualpages/index.md)
[Index of all manual pages](/manualpages/singleindex.md)