:orphan:
# PCApplyTranspose
Applies the transpose of preconditioner to a vector.
## Synopsis
```
#include "petscksp.h"
PetscErrorCode PCApplyTranspose(PC pc, Vec x, Vec y)
```
Collective
## Input Parameters
- ***pc -*** the preconditioner context
- ***x -*** input vector
## Output Parameter
- ***y -*** output vector
## Note
For complex numbers this applies the non-Hermitian transpose.
## Developer Note
We need to implement a `PCApplyHermitianTranspose()`
## See Also
`PC`, `PCApply()`, `PCApplyBAorAB()`, `PCApplyBAorABTranspose()`, `PCApplyTransposeExists()`
## Level
developer
## Location
src/ksp/pc/interface/precon.c
## Implementations
PCApplyTranspose_ASM in src/ksp/pc/impls/asm/asm.c
PCApplyTranspose_BDDC in src/ksp/pc/impls/bddc/bddc.c
PCApplyTranspose_BDDCIPC in src/ksp/pc/impls/bddc/bddc.c
PCApplyTranspose_Eisenstat in src/ksp/pc/impls/eisens/eisen.c
PCApplyTranspose_Cholesky in src/ksp/pc/impls/factor/cholesky/cholesky.c
PCApplyTranspose_ILU in src/ksp/pc/impls/factor/ilu/ilu.c
PCApplyTranspose_LU in src/ksp/pc/impls/factor/lu/lu.c
PCApplyTranspose_QR in src/ksp/pc/impls/factor/qr/qr.c
PCApplyTranspose_FieldSplit in src/ksp/pc/impls/fieldsplit/fieldsplit.c
PCApplyTranspose_GASM in src/ksp/pc/impls/gasm/gasm.c
PCApplyTranspose_H2OPUS in src/ksp/pc/impls/h2opus/pch2opus.c
PCApplyTranspose_KSP in src/ksp/pc/impls/ksp/pcksp.c
PCApplyTranspose_Mat in src/ksp/pc/impls/mat/pcmat.c
PCApplyTranspose_MG in src/ksp/pc/impls/mg/mg.c
PCApplyTranspose_PBJacobi in src/ksp/pc/impls/pbjacobi/pbjacobi.c
PCApplyTranspose_Redundant in src/ksp/pc/impls/redundant/redundant.c
PCApplyTranspose_Shell in src/ksp/pc/impls/shell/shellpc.c
PCApplyTranspose_SOR in src/ksp/pc/impls/sor/sor.c
PCApplyTranspose_SVD in src/ksp/pc/impls/svd/svd.c
PCApplyTranspose_VPBJacobi in src/ksp/pc/impls/vpbjacobi/vpbjacobi.c
---
[Edit on GitLab](https://gitlab.com/petsc/petsc/-/edit/release/src/ksp/pc/interface/precon.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)