MatHYPRESetPreallocation#
Preallocates memory for a sparse parallel matrix in HYPRE IJ format
Synopsis#
PetscErrorCode MatHYPRESetPreallocation(Mat A, PetscInt dnz, const PetscInt dnnz[], PetscInt onz, const PetscInt onnz[])
Collective
Input Parameters#
- A - the matrix 
- dnz - number of nonzeros per row in DIAGONAL portion of local submatrix (same value is used for all local rows) 
- dnnz - array containing the number of nonzeros in the various rows of the DIAGONAL portion of the local submatrix (possibly different for each row) or - NULL(- PETSC_NULL_INTEGERin Fortran), if- d_nzis used to specify the nonzero structure. The size of this array is equal to the number of local rows, i.e- m. For matrices that will be factored, you must leave room for (and set) the diagonal entry even if it is zero.
- onz - number of nonzeros per row in the OFF-DIAGONAL portion of local submatrix (same value is used for all local rows). 
- onnz - array containing the number of nonzeros in the various rows of the OFF-DIAGONAL portion of the local submatrix (possibly different for each row) or - NULL(- PETSC_NULL_INTEGERin Fortran), if- o_nzis used to specify the nonzero structure. The size of this array is equal to the number of local rows, i.e- m.
Note#
If the *nnz parameter is given then the *nz parameter is ignored; for sequential matrices, onz and onnz are ignored.
See Also#
Matrices, Mat, MatCreate(), MatMPIAIJSetPreallocation(), MATHYPRE, MATAIJ
Level#
intermediate
Location#
Examples#
Implementations#
MatHYPRESetPreallocation_HYPRE() in src/mat/impls/hypre/mhypre.c
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