MatSetPreallocationCOOLocal#

set preallocation for matrices using a coordinate format of the entries with local indices

Synopsis#

#include "petscmat.h"  
PetscErrorCode MatSetPreallocationCOOLocal(Mat A, PetscCount ncoo, PetscInt coo_i[], PetscInt coo_j[])

Collective

Input Parameters#

A - matrix being preallocated
ncoo - number of entries
coo_i - row indices (local numbering; may be modified)
coo_j - column indices (local numbering; may be modified)

Notes#

The local indices are translated using the local to global mapping, thus MatSetLocalToGlobalMapping() must have been called prior to this function. For matrices created with DMCreateMatrix() the local to global mapping is often already provided.

The indices coo_i and coo_j may be modified within this function. They might be translated to corresponding global indices, but the caller should not rely on them having any specific value after this function returns. The arrays can be freed or reused immediately after this function returns.

Entries can be repeated, see MatSetValuesCOO(). Entries with negative row or column indices are allowed but will be ignored. The corresponding entries in MatSetValuesCOO() will be ignored too. Remote entries are allowed and will be properly added or inserted to the matrix.