petsc-3.12.5 2020-03-29
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MatCreateSeqAIJSELL

Creates a sparse matrix of type SEQAIJSELL. This type inherits from AIJ and is largely identical, but keeps a "shadow" copy of the matrix in SEQSELL format, which is used when this format may be more suitable for a requested operation. Currently, SEQSELL format is used for MatMult, MatMultTranspose, MatMultAdd, MatMultTransposeAdd, and MatSOR operations. Because SEQAIJSELL is a subtype of SEQAIJ, the option "-mat_seqaij_type seqaijsell" can be used to make sequential AIJ matrices default to being instances of MATSEQAIJSELL.

Synopsis

PetscErrorCode  MatCreateSeqAIJSELL(MPI_Comm comm,PetscInt m,PetscInt n,PetscInt nz,const PetscInt nnz[],Mat *A)
Collective

Input Parameters

comm - MPI communicator, set to PETSC_COMM_SELF
m - number of rows
n - number of columns
nz - number of nonzeros per row (same for all rows)
nnz - array containing the number of nonzeros in the various rows (possibly different for each row) or NULL

Output Parameter

A -the matrix

Options Database Keys

-mat_aijsell_eager_shadow -Construct shadow matrix upon matrix assembly; default is to take a "lazy" approach, performing this step the first time the matrix is applied

Notes

If nnz is given then nz is ignored

See Also

MatCreate(), MatCreateMPIAIJSELL(), MatSetValues()

Level

intermediate

Location

src/mat/impls/aij/seq/aijsell/aijsell.c
Index of all Mat routines
Table of Contents for all manual pages
Index of all manual pages