MatCreateSeqAIJFromTriple#

Creates an sequential MATSEQAIJ matrix using matrix elements (in COO format) provided by the user.

Synopsis#

#include "petscmat.h" 
PetscErrorCode MatCreateSeqAIJFromTriple(MPI_Comm comm, PetscInt m, PetscInt n, PetscInt i[], PetscInt j[], PetscScalar a[], Mat *mat, PetscInt nz, PetscBool idx)

Collective

Input Parameters#

comm - must be an MPI communicator of size 1
m - number of rows
n - number of columns
i - row indices
j - column indices
a - matrix values
nz - number of nonzeros
idx - if the i and j indices start with 1 use PETSC_TRUE otherwise use PETSC_FALSE

Output Parameter#

mat - the matrix

Example#

For the following matrix, the input data expected is as shown (using 0 based indexing)

        1 0 0
        2 0 3
        4 5 6

        i =  {0,1,1,2,2,2}
        j =  {0,0,2,0,1,2}
        v =  {1,2,3,4,5,6}

Note#

Instead of using this function, users should also consider MatSetPreallocationCOO() and MatSetValuesCOO(), which allow repeated or remote entries, and are particularly useful in iterative applications.