MatCreateMPISBAIJWithArrays — PETSc 3.25.0 documentation

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# MatCreateMPISBAIJWithArrays

creates a `MATMPISBAIJ` matrix using arrays that contain in standard CSR format for the local rows.

## Synopsis

    #include "petscmat.h"
    PetscErrorCode MatCreateMPISBAIJWithArrays(MPI_Comm comm, PetscInt bs, PetscInt m, PetscInt n, PetscInt M, PetscInt N, const PetscInt i[], const PetscInt j[], const PetscScalar a[], Mat *mat)

Collective

## Input Parameters

- comm - MPI communicator

- bs - the block size, only a block size of 1 is supported

- m - number of local rows (Cannot be `PETSC_DECIDE`)

- n - This value should be the same as the local size used in creating the x vector for the matrix-vector product \( y = Ax \). (or `PETSC_DECIDE` to have calculated if `N` is given) For square matrices `n` is almost always `m`.

- M - number of global rows (or `PETSC_DETERMINE` to have calculated if `m` is given)

- N - number of global columns (or `PETSC_DETERMINE` to have calculated if `n` is given)

- i - row indices; that is i[0] = 0, i[row] = i[row-1] + number of block elements in that row block row of the matrix

- j - column indices

- a - matrix values

## Output Parameter

- mat - the matrix

## Notes

The `i`, `j`, and `a` arrays ARE copied by this routine into the internal format used by PETSc; thus you CANNOT change the matrix entries by changing the values of `a` after you have called this routine. Use `MatCreateMPIAIJWithSplitArrays()` to avoid needing to copy the arrays.

The `i` and `j` indices are 0 based, and `i` indices are indices corresponding to the local `j` array.

## See Also

Matrices, `Mat`, `MATMPISBAIJ`, `MatCreate()`, `MatCreateSeqAIJ()`, `MatSetValues()`, `MatMPIAIJSetPreallocation()`, `MatMPIAIJSetPreallocationCSR()`, `MATMPIAIJ`, `MatCreateAIJ()`, `MatCreateMPIAIJWithSplitArrays()`, `MatMPISBAIJSetPreallocationCSR()`

## Level

intermediate

## Location

src/mat/impls/sbaij/mpi/mpisbaij.c

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Index of all manual pages