Actual source code: ex71.c


  2: static char help[] = "Passes a sparse matrix to MATLAB.\n\n";

  4: #include <petscmat.h>

  6: int main(int argc, char **args)
  7: {
  8:   PetscInt    m = 4, n = 5, i, j, II, J;
  9:   PetscScalar one = 1.0, v;
 10:   Vec         x;
 11:   Mat         A;

 13:   PetscFunctionBeginUser;
 14:   PetscCall(PetscInitialize(&argc, &args, (char *)0, help));
 15:   PetscCall(PetscOptionsGetInt(NULL, NULL, "-m", &m, NULL));
 16:   PetscCall(PetscOptionsGetInt(NULL, NULL, "-n", &n, NULL));

 18:   PetscCall(MatCreate(PETSC_COMM_WORLD, &A));
 19:   PetscCall(MatSetSizes(A, PETSC_DECIDE, PETSC_DECIDE, m * n, m * n));
 20:   PetscCall(MatSetFromOptions(A));
 21:   PetscCall(MatSetUp(A));

 23:   for (i = 0; i < m; i++) {
 24:     for (j = 0; j < n; j++) {
 25:       v  = -1.0;
 26:       II = j + n * i;
 27:       if (i > 0) {
 28:         J = II - n;
 29:         PetscCall(MatSetValues(A, 1, &II, 1, &J, &v, INSERT_VALUES));
 30:       }
 31:       if (i < m - 1) {
 32:         J = II + n;
 33:         PetscCall(MatSetValues(A, 1, &II, 1, &J, &v, INSERT_VALUES));
 34:       }
 35:       if (j > 0) {
 36:         J = II - 1;
 37:         PetscCall(MatSetValues(A, 1, &II, 1, &J, &v, INSERT_VALUES));
 38:       }
 39:       if (j < n - 1) {
 40:         J = II + 1;
 41:         PetscCall(MatSetValues(A, 1, &II, 1, &J, &v, INSERT_VALUES));
 42:       }
 43:       v = 4.0;
 44:       PetscCall(MatSetValues(A, 1, &II, 1, &II, &v, INSERT_VALUES));
 45:     }
 46:   }
 47:   PetscCall(MatAssemblyBegin(A, MAT_FINAL_ASSEMBLY));
 48:   PetscCall(MatAssemblyEnd(A, MAT_FINAL_ASSEMBLY));
 49: #if defined(PETSC_USE_SOCKET_VIEWER)
 50:   PetscCall(MatView(A, PETSC_VIEWER_SOCKET_WORLD));
 51: #endif
 52:   PetscCall(VecCreateSeq(PETSC_COMM_SELF, m, &x));
 53:   PetscCall(VecSet(x, one));
 54: #if defined(PETSC_USE_SOCKET_VIEWER)
 55:   PetscCall(VecView(x, PETSC_VIEWER_SOCKET_WORLD));
 56: #endif

 58:   PetscCall(PetscSleep(30));

 60:   PetscCall(VecDestroy(&x));
 61:   PetscCall(MatDestroy(&A));
 62:   PetscCall(PetscFinalize());
 63:   return 0;
 64: }

 66: /*TEST

 68:    test:
 69:      TODO: cannot test with socket viewer

 71: TEST*/