2: static char help[] ="Tests MatCreateMPIAIJWithArrays() abd MatUpdateMPIAIJWithArrays()\n";

  4:  #include <petscmat.h>

  6: /*
  7:  * This is an extremely simple example to test MatUpdateMPIAIJWithArrays()
  8:  *
  9:  * A =

 11:    1    2   0   3  0  0
 12:    0    4   5   0  0  6
 13:    7    0   8   0  9  0
 14:    0   10  11  12  0  13
 15:    0   14  15   0  0  16
 16:   17    0   0   0  0  18
 17:  *
 18:  * */

 20: int main(int argc,char **argv)
 21: {
 23:   Mat            A;
 24:   PetscInt       i[3][3] = {{0, 3, 6},{0, 3, 7},{0, 3, 5}};
 25:   PetscInt       j[3][7] = {{0, 1, 3, 1, 2, 5, -1},{0, 2, 4, 1, 2, 3, 5},{1, 2, 5, 0, 5, -1, -1}};
 26:   PetscScalar    a[3][7] = {{1, 2, 3, 4, 5, 6, -1}, {7, 8, 9, 10, 11, 12, 13},{14, 15, 16, 17, 18, -1, -1}};
 27:   PetscScalar    anew[3][7] = {{10, 20, 30, 40, 50, 60, -1}, {70, 80, 90, 100, 110, 120, 130},{140, 150, 160, 170, 180, -1, -1}};
 28:   MPI_Comm       comm;
 29:   PetscMPIInt    rank,size;

 31:   PetscInitialize(&argc,&argv,NULL,help);if (ierr) return ierr;
 32:   comm = PETSC_COMM_WORLD;
 33:   MPI_Comm_rank(comm,&rank);
 34:   MPI_Comm_size(comm,&size);
 35:   if (size != 3) SETERRQ(comm,PETSC_ERR_ARG_INCOMP,"You have to use three MPI processes to run this example \n");
 36:   MatCreateMPIAIJWithArrays(comm,2,2,PETSC_DETERMINE,PETSC_DETERMINE,i[rank],j[rank],a[rank],&A);
 37:   MatView(A,NULL);
 38:   MatUpdateMPIAIJWithArrays(A,2,2,PETSC_DETERMINE,PETSC_DETERMINE,i[rank],j[rank],anew[rank]);
 39:   MatView(A,NULL);
 40:   MatUpdateMPIAIJWithArrays(A,2,2,PETSC_DETERMINE,PETSC_DETERMINE,i[rank],j[rank],a[rank]);
 41:   MatView(A,NULL);
 42:   MatDestroy(&A);
 43:   PetscFinalize();
 44:   return ierr;
 45: }

 47: /*TEST
 48:    test:
 49:      nsize: 3

 51: TEST*/