Actual source code: ex71.c

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

  3: #include <petscmat.h>

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

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

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

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

 57:   PetscCall(PetscSleep(30));

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

 65: /*TEST

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

 70: TEST*/