# MatGetRedundantMatrix

Create redundant matrices and put them into processors of subcommunicators.

### Synopsis

    #include "petscmat.h"
    PetscErrorCode  MatGetRedundantMatrix(Mat mat,PetscInt nsubcomm,MPI_Comm subcomm,PetscInt mlocal_red,MatReuse reuse,Mat *matredundant)

Collective on Mat

### Input Parameters

| mat | - the matrix
| nsubcomm | - the number of subcommunicators (= number of redundant pareallel or sequential matrices)
| subcomm | - MPI communicator split from the communicator where mat resides in
| mlocal_red | - number of local rows of the redundant matrix
| reuse | - either MAT_INITIAL_MATRIX or MAT_REUSE_MATRIX

### Output Parameter

matredundant -redundant matrix

### Notes

MAT_REUSE_MATRIX can only be used when the nonzero structure of the original matrix has not changed from that last call to MatGetRedundantMatrix().

This routine creates the duplicated matrices in subcommunicators; you should NOT create them before calling it.

Only MPIAIJ matrix is supported.

### See Also

MatDestroy()

Level:advanced
Location: src/mat/interface/matrix.c
Index of all Mat routines
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Index of all manual pages