:orphan:
# MatIsTranspose
Test whether a matrix is another one's transpose, or its own, in which case it tests symmetry.
## Synopsis
```
#include "petscmat.h"
PetscErrorCode MatIsTranspose(Mat A, Mat B, PetscReal tol, PetscBool *flg)
```
Collective
## Input Parameters
- ***A -*** the matrix to test
- ***B -*** the matrix to test against, this can equal the first parameter
- ***tol -*** tolerance, differences between entries smaller than this are counted as zero
## Output Parameter
- ***flg -*** the result
## Notes
Only available for `MATAIJ` matrices.
The sequential algorithm has a running time of the order of the number of nonzeros; the parallel
test involves parallel copies of the block-offdiagonal parts of the matrix.
## See Also
[](ch_matrices), `Mat`, `MatTranspose()`, `MatIsSymmetric()`, `MatIsHermitian()`
## Level
intermediate
## Location
src/mat/interface/matrix.c
## Implementations
MatIsTranspose_MPIAIJ in src/mat/impls/aij/mpi/mpiaij.c
MatIsTranspose_SeqAIJ in src/mat/impls/aij/seq/aij.c
MatIsTranspose_SeqBAIJ in src/mat/impls/baij/seq/baij.c
MatIsTranspose_MPISELL in src/mat/impls/sell/mpi/mpisell.c
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[Edit on GitLab](https://gitlab.com/petsc/petsc/-/edit/release/src/mat/interface/matrix.c)
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