Actual source code: ex13.c


  2: static char help[] = "Tests copying and ordering uniprocessor row-based sparse matrices.\n\n";

  4: #include <petscmat.h>

  6: int main(int argc, char **args)
  7: {
  8:   Mat         C, A;
  9:   PetscInt    i, j, m = 5, n = 5, Ii, J;
 10:   PetscScalar v;
 11:   IS          perm, iperm;

 14:   PetscInitialize(&argc, &args, (char *)0, help);
 15:   MatCreateSeqAIJ(PETSC_COMM_SELF, m * n, m * n, 5, NULL, &C);
 16:   /* create the matrix for the five point stencil, YET AGAIN*/
 17:   for (i = 0; i < m; i++) {
 18:     for (j = 0; j < n; j++) {
 19:       v  = -1.0;
 20:       Ii = j + n * i;
 21:       if (i > 0) {
 22:         J = Ii - n;
 23:         MatSetValues(C, 1, &Ii, 1, &J, &v, INSERT_VALUES);
 24:       }
 25:       if (i < m - 1) {
 26:         J = Ii + n;
 27:         MatSetValues(C, 1, &Ii, 1, &J, &v, INSERT_VALUES);
 28:       }
 29:       if (j > 0) {
 30:         J = Ii - 1;
 31:         MatSetValues(C, 1, &Ii, 1, &J, &v, INSERT_VALUES);
 32:       }
 33:       if (j < n - 1) {
 34:         J = Ii + 1;
 35:         MatSetValues(C, 1, &Ii, 1, &J, &v, INSERT_VALUES);
 36:       }
 37:       v = 4.0;
 38:       MatSetValues(C, 1, &Ii, 1, &Ii, &v, INSERT_VALUES);
 39:     }
 40:   }
 41:   MatAssemblyBegin(C, MAT_FINAL_ASSEMBLY);
 42:   MatAssemblyEnd(C, MAT_FINAL_ASSEMBLY);

 44:   MatConvert(C, MATSAME, MAT_INITIAL_MATRIX, &A);

 46:   MatGetOrdering(A, MATORDERINGND, &perm, &iperm);
 47:   ISView(perm, PETSC_VIEWER_STDOUT_SELF);
 48:   ISView(iperm, PETSC_VIEWER_STDOUT_SELF);
 49:   MatView(A, PETSC_VIEWER_STDOUT_SELF);

 51:   ISDestroy(&perm);
 52:   ISDestroy(&iperm);
 53:   MatDestroy(&C);
 54:   MatDestroy(&A);
 55:   PetscFinalize();
 56:   return 0;
 57: }

 59: /*TEST

 61:    test:
 62:       filter: grep -v " MPI process"

 64: TEST*/