: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
<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/ksp/pc/interface/precon.c.html#PCApplyTranspose">src/ksp/pc/interface/precon.c</A>

## Implementations

<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/ksp/pc/impls/asm/asm.c.html#PCApplyTranspose_ASM">PCApplyTranspose_ASM in src/ksp/pc/impls/asm/asm.c</A><BR>
<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/ksp/pc/impls/bddc/bddc.c.html#PCApplyTranspose_BDDC">PCApplyTranspose_BDDC in src/ksp/pc/impls/bddc/bddc.c</A><BR>
<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/ksp/pc/impls/bddc/bddc.c.html#PCApplyTranspose_BDDCIPC">PCApplyTranspose_BDDCIPC in src/ksp/pc/impls/bddc/bddc.c</A><BR>
<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/ksp/pc/impls/eisens/eisen.c.html#PCApplyTranspose_Eisenstat">PCApplyTranspose_Eisenstat in src/ksp/pc/impls/eisens/eisen.c</A><BR>
<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/ksp/pc/impls/factor/cholesky/cholesky.c.html#PCApplyTranspose_Cholesky">PCApplyTranspose_Cholesky in src/ksp/pc/impls/factor/cholesky/cholesky.c</A><BR>
<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/ksp/pc/impls/factor/ilu/ilu.c.html#PCApplyTranspose_ILU">PCApplyTranspose_ILU in src/ksp/pc/impls/factor/ilu/ilu.c</A><BR>
<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/ksp/pc/impls/factor/lu/lu.c.html#PCApplyTranspose_LU">PCApplyTranspose_LU in src/ksp/pc/impls/factor/lu/lu.c</A><BR>
<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/ksp/pc/impls/factor/qr/qr.c.html#PCApplyTranspose_QR">PCApplyTranspose_QR in src/ksp/pc/impls/factor/qr/qr.c</A><BR>
<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/ksp/pc/impls/fieldsplit/fieldsplit.c.html#PCApplyTranspose_FieldSplit">PCApplyTranspose_FieldSplit in src/ksp/pc/impls/fieldsplit/fieldsplit.c</A><BR>
<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/ksp/pc/impls/gasm/gasm.c.html#PCApplyTranspose_GASM">PCApplyTranspose_GASM in src/ksp/pc/impls/gasm/gasm.c</A><BR>
<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/ksp/pc/impls/h2opus/pch2opus.c.html#PCApplyTranspose_H2OPUS">PCApplyTranspose_H2OPUS in src/ksp/pc/impls/h2opus/pch2opus.c</A><BR>
<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/ksp/pc/impls/ksp/pcksp.c.html#PCApplyTranspose_KSP">PCApplyTranspose_KSP in src/ksp/pc/impls/ksp/pcksp.c</A><BR>
<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/ksp/pc/impls/mat/pcmat.c.html#PCApplyTranspose_Mat">PCApplyTranspose_Mat in src/ksp/pc/impls/mat/pcmat.c</A><BR>
<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/ksp/pc/impls/mg/mg.c.html#PCApplyTranspose_MG">PCApplyTranspose_MG in src/ksp/pc/impls/mg/mg.c</A><BR>
<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/ksp/pc/impls/pbjacobi/pbjacobi.c.html#PCApplyTranspose_PBJacobi">PCApplyTranspose_PBJacobi in src/ksp/pc/impls/pbjacobi/pbjacobi.c</A><BR>
<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/ksp/pc/impls/redundant/redundant.c.html#PCApplyTranspose_Redundant">PCApplyTranspose_Redundant in src/ksp/pc/impls/redundant/redundant.c</A><BR>
<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/ksp/pc/impls/shell/shellpc.c.html#PCApplyTranspose_Shell">PCApplyTranspose_Shell in src/ksp/pc/impls/shell/shellpc.c</A><BR>
<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/ksp/pc/impls/sor/sor.c.html#PCApplyTranspose_SOR">PCApplyTranspose_SOR in src/ksp/pc/impls/sor/sor.c</A><BR>
<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/ksp/pc/impls/svd/svd.c.html#PCApplyTranspose_SVD">PCApplyTranspose_SVD in src/ksp/pc/impls/svd/svd.c</A><BR>
<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/ksp/pc/impls/vpbjacobi/vpbjacobi.c.html#PCApplyTranspose_VPBJacobi">PCApplyTranspose_VPBJacobi in src/ksp/pc/impls/vpbjacobi/vpbjacobi.c</A><BR>


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[Edit on GitLab](https://gitlab.com/petsc/petsc/-/edit/release/src/ksp/pc/interface/precon.c)


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