MatSeqBAIJSetPreallocationCSR#

Creates a sparse sequential matrix in MATSEQBAIJ format using the given nonzero structure and (optional) numerical values

Synopsis#

#include "petscmat.h"  
PetscErrorCode MatSeqBAIJSetPreallocationCSR(Mat B, PetscInt bs, const PetscInt i[], const PetscInt j[], const PetscScalar v[])

Collective

Input Parameters#

B - the matrix
bs - the blocksize
i - the indices into j for the start of each local row (starts with zero)
j - the column indices for each local row (starts with zero) these must be sorted for each row
v - optional values in the matrix

Notes#

The order of the entries in values is specified by the MatOption MAT_ROW_ORIENTED. For example, C programs may want to use the default MAT_ROW_ORIENTED of PETSC_TRUE and use an array v[nnz][bs][bs] where the second index is over rows within a block and the last index is over columns within a block row. Fortran programs will likely set MAT_ROW_ORIENTED of PETSC_FALSE and use a Fortran array v(bs,bs,nnz) in which the first index is over rows within a block column and the second index is over columns within a block.

Though this routine has Preallocation() in the name it also sets the exact nonzero locations of the matrix entries and usually the numerical values as well