Actual source code: ex64.c
1: static char help[] = "Saves 4by4 block matrix.\n\n";
3: #include <petscmat.h>
5: int main(int argc, char **args)
6: {
7: Mat A;
8: PetscInt i, j;
9: PetscMPIInt size;
10: PetscViewer fd;
11: PetscScalar values[16], one = 1.0;
12: Vec x;
14: PetscFunctionBeginUser;
15: PetscCall(PetscInitialize(&argc, &args, (char *)0, help));
16: PetscCallMPI(MPI_Comm_size(PETSC_COMM_WORLD, &size));
17: PetscCheck(size == 1, PETSC_COMM_WORLD, PETSC_ERR_WRONG_MPI_SIZE, m "Can only run on one processor");
19: /*
20: Open binary file. Note that we use FILE_MODE_WRITE to indicate
21: writing to this file.
22: */
23: PetscCall(PetscViewerBinaryOpen(PETSC_COMM_WORLD, "4by4", FILE_MODE_WRITE, &fd));
25: PetscCall(MatCreateSeqBAIJ(PETSC_COMM_WORLD, 4, 12, 12, 0, 0, &A));
27: for (i = 0; i < 16; i++) values[i] = i;
28: for (i = 0; i < 4; i++) values[4 * i + i] += 5;
29: i = 0;
30: j = 0;
31: PetscCall(MatSetValuesBlocked(A, 1, &i, 1, &j, values, INSERT_VALUES));
33: for (i = 0; i < 16; i++) values[i] = i;
34: i = 0;
35: j = 2;
36: PetscCall(MatSetValuesBlocked(A, 1, &i, 1, &j, values, INSERT_VALUES));
38: for (i = 0; i < 16; i++) values[i] = i;
39: i = 1;
40: j = 0;
41: PetscCall(MatSetValuesBlocked(A, 1, &i, 1, &j, values, INSERT_VALUES));
43: for (i = 0; i < 16; i++) values[i] = i;
44: for (i = 0; i < 4; i++) values[4 * i + i] += 6;
45: i = 1;
46: j = 1;
47: PetscCall(MatSetValuesBlocked(A, 1, &i, 1, &j, values, INSERT_VALUES));
49: for (i = 0; i < 16; i++) values[i] = i;
50: i = 2;
51: j = 0;
52: PetscCall(MatSetValuesBlocked(A, 1, &i, 1, &j, values, INSERT_VALUES));
54: for (i = 0; i < 16; i++) values[i] = i;
55: for (i = 0; i < 4; i++) values[4 * i + i] += 7;
56: i = 2;
57: j = 2;
58: PetscCall(MatSetValuesBlocked(A, 1, &i, 1, &j, values, INSERT_VALUES));
60: PetscCall(MatAssemblyBegin(A, MAT_FINAL_ASSEMBLY));
61: PetscCall(MatAssemblyEnd(A, MAT_FINAL_ASSEMBLY));
62: PetscCall(MatView(A, fd));
63: PetscCall(MatDestroy(&A));
65: PetscCall(VecCreateSeq(PETSC_COMM_WORLD, 12, &x));
66: PetscCall(VecSet(x, one));
67: PetscCall(VecView(x, fd));
68: PetscCall(VecDestroy(&x));
70: PetscCall(PetscViewerDestroy(&fd));
71: PetscCall(PetscFinalize());
72: return 0;
73: }