# MatTranspose
Computes an in-place or out-of-place transpose of a matrix. 
## Synopsis
```
#include "petscmat.h" 
PetscErrorCode MatTranspose(Mat mat, MatReuse reuse, Mat *B)
```
Collective


## Input Parameters

- ***mat -*** the matrix to transpose
- ***reuse -*** either `MAT_INITIAL_MATRIX`, `MAT_REUSE_MATRIX`, or `MAT_INPLACE_MATRIX`



## Output Parameter

- ***B -*** the transpose



## Notes
If you use `MAT_INPLACE_MATRIX` then you must pass in &mat for B

`MAT_REUSE_MATRIX` uses the B matrix obtained from a previous call to this function with `MAT_INITIAL_MATRIX`. If you already have a matrix to contain the
transpose, call `MatTransposeSetPrecursor`(mat,B) before calling this routine.

If the nonzero structure of mat changed from the previous call to this function with the same matrices an error will be generated for some matrix types.

Consider using `MatCreateTranspose()` instead if you only need a matrix that behaves like the transpose, but don't need the storage to be changed.

If mat is unchanged from the last call this function returns immediately without recomputing the result

If you only need the symbolic transpose, and not the numerical values, use `MatTransposeSymbolic()`




## See Also
 `MatTransposeSetPrecursor()`, `MatMultTranspose()`, `MatMultTransposeAdd()`, `MatIsTranspose()`, `MatReuse`, `MAT_INITIAL_MATRIX`, `MAT_REUSE_MATRIX`, `MAT_INPLACE_MATRIX`,
`MatTransposeSymbolic()`

## Level
intermediate

## Location
<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/mat/interface/matrix.c.html#MatTranspose">src/mat/interface/matrix.c</A>

## Examples
<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/ksp/ksp/tutorials/ex43.c.html">src/ksp/ksp/tutorials/ex43.c.html</A><BR>
<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/ksp/ksp/tutorials/ex65.c.html">src/ksp/ksp/tutorials/ex65.c.html</A><BR>
<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/ksp/ksp/tutorials/ex74.c.html">src/ksp/ksp/tutorials/ex74.c.html</A><BR>
<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/snes/tutorials/ex70.c.html">src/snes/tutorials/ex70.c.html</A><BR>
<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/tao/pde_constrained/tutorials/hyperbolic.c.html">src/tao/pde_constrained/tutorials/hyperbolic.c.html</A><BR>
<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/tao/pde_constrained/tutorials/parabolic.c.html">src/tao/pde_constrained/tutorials/parabolic.c.html</A><BR>

## Implementations

<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/mat/impls/aij/mpi/mpiaij.c.html#MatTranspose_MPIAIJ">MatTranspose_MPIAIJ in src/mat/impls/aij/mpi/mpiaij.c</A><BR>
<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/mat/impls/aij/seq/kokkos/aijkok.kokkos.cxx.html#MatTranspose_SeqAIJKokkos">MatTranspose_SeqAIJKokkos in src/mat/impls/aij/seq/kokkos/aijkok.kokkos.cxx</A><BR>
<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/mat/impls/aij/seq/symtranspose.c.html#MatTranspose_SeqAIJ">MatTranspose_SeqAIJ in src/mat/impls/aij/seq/symtranspose.c</A><BR>
<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/mat/impls/baij/mpi/mpibaij.c.html#MatTranspose_MPIBAIJ">MatTranspose_MPIBAIJ in src/mat/impls/baij/mpi/mpibaij.c</A><BR>
<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/mat/impls/baij/seq/baij.c.html#MatTranspose_SeqBAIJ">MatTranspose_SeqBAIJ in src/mat/impls/baij/seq/baij.c</A><BR>
<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/mat/impls/dense/mpi/mpidense.c.html#MatTranspose_MPIDense">MatTranspose_MPIDense in src/mat/impls/dense/mpi/mpidense.c</A><BR>
<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/mat/impls/dense/seq/dense.c.html#MatTranspose_SeqDense">MatTranspose_SeqDense in src/mat/impls/dense/seq/dense.c</A><BR>
<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/mat/impls/elemental/matelem.cxx.html#MatTranspose_Elemental">MatTranspose_Elemental in src/mat/impls/elemental/matelem.cxx</A><BR>
<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/mat/impls/htool/htool.cxx.html#MatTranspose_Htool">MatTranspose_Htool in src/mat/impls/htool/htool.cxx</A><BR>
<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/mat/impls/is/matis.c.html#MatTranspose_IS">MatTranspose_IS in src/mat/impls/is/matis.c</A><BR>
<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/mat/impls/nest/matnest.c.html#MatTranspose_Nest">MatTranspose_Nest in src/mat/impls/nest/matnest.c</A><BR>
<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/mat/impls/sbaij/mpi/mpisbaij.c.html#MatTranspose_MPISBAIJ">MatTranspose_MPISBAIJ in src/mat/impls/sbaij/mpi/mpisbaij.c</A><BR>
<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/mat/impls/sbaij/seq/sbaij.c.html#MatTranspose_SeqSBAIJ">MatTranspose_SeqSBAIJ in src/mat/impls/sbaij/seq/sbaij.c</A><BR>
<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/mat/impls/scalapack/matscalapack.c.html#MatTranspose_ScaLAPACK">MatTranspose_ScaLAPACK in src/mat/impls/scalapack/matscalapack.c</A><BR>


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


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