xref: /petsc/src/mat/tests/ex25.c (revision d71ae5a4db6382e7f06317b8d368875286fe9008)
1c4762a1bSJed Brown 
2c4762a1bSJed Brown static char help[] = "Tests MatTranspose()\n\n";
3c4762a1bSJed Brown 
4c4762a1bSJed Brown #include <petscmat.h>
5c4762a1bSJed Brown 
6*d71ae5a4SJacob Faibussowitsch int main(int argc, char **args)
7*d71ae5a4SJacob Faibussowitsch {
8c4762a1bSJed Brown   Mat         C, A;
9c4762a1bSJed Brown   PetscScalar v;
10c4762a1bSJed Brown   PetscInt    i, j, m = 4, n = 4, Ii, J, Istart, Iend;
11c4762a1bSJed Brown   PetscMPIInt rank, size;
12c4762a1bSJed Brown   PetscBool   equal = PETSC_FALSE;
13c4762a1bSJed Brown 
14327415f7SBarry Smith   PetscFunctionBeginUser;
159566063dSJacob Faibussowitsch   PetscCall(PetscInitialize(&argc, &args, (char *)0, help));
169566063dSJacob Faibussowitsch   PetscCallMPI(MPI_Comm_rank(PETSC_COMM_WORLD, &rank));
179566063dSJacob Faibussowitsch   PetscCallMPI(MPI_Comm_size(PETSC_COMM_WORLD, &size));
18c4762a1bSJed Brown 
199566063dSJacob Faibussowitsch   PetscCall(PetscOptionsGetInt(NULL, NULL, "-m", &m, NULL));
20c4762a1bSJed Brown   n = m;
21c4762a1bSJed Brown 
229566063dSJacob Faibussowitsch   PetscCall(MatCreateAIJ(PETSC_COMM_WORLD, PETSC_DECIDE, PETSC_DECIDE, m * n, m * n, 5, NULL, 5, NULL, &C));
23c4762a1bSJed Brown 
24c4762a1bSJed Brown   /* create the symmetric matrix for the five point stencil */
259566063dSJacob Faibussowitsch   PetscCall(MatGetOwnershipRange(C, &Istart, &Iend));
26c4762a1bSJed Brown   for (Ii = Istart; Ii < Iend; Ii++) {
279371c9d4SSatish Balay     v = -1.0;
289371c9d4SSatish Balay     i = Ii / n;
299371c9d4SSatish Balay     j = Ii - i * n;
309371c9d4SSatish Balay     if (i > 0) {
319371c9d4SSatish Balay       J = Ii - n;
329371c9d4SSatish Balay       PetscCall(MatSetValues(C, 1, &Ii, 1, &J, &v, INSERT_VALUES));
339371c9d4SSatish Balay     }
349371c9d4SSatish Balay     if (i < m - 1) {
359371c9d4SSatish Balay       J = Ii + n;
369371c9d4SSatish Balay       PetscCall(MatSetValues(C, 1, &Ii, 1, &J, &v, INSERT_VALUES));
379371c9d4SSatish Balay     }
389371c9d4SSatish Balay     if (j > 0) {
399371c9d4SSatish Balay       J = Ii - 1;
409371c9d4SSatish Balay       PetscCall(MatSetValues(C, 1, &Ii, 1, &J, &v, INSERT_VALUES));
419371c9d4SSatish Balay     }
429371c9d4SSatish Balay     if (j < n - 1) {
439371c9d4SSatish Balay       J = Ii + 1;
449371c9d4SSatish Balay       PetscCall(MatSetValues(C, 1, &Ii, 1, &J, &v, INSERT_VALUES));
459371c9d4SSatish Balay     }
469371c9d4SSatish Balay     v = 4.0;
479371c9d4SSatish Balay     PetscCall(MatSetValues(C, 1, &Ii, 1, &Ii, &v, INSERT_VALUES));
48c4762a1bSJed Brown   }
499566063dSJacob Faibussowitsch   PetscCall(MatAssemblyBegin(C, MAT_FINAL_ASSEMBLY));
509566063dSJacob Faibussowitsch   PetscCall(MatAssemblyEnd(C, MAT_FINAL_ASSEMBLY));
51c4762a1bSJed Brown 
529566063dSJacob Faibussowitsch   PetscCall(MatTranspose(C, MAT_INITIAL_MATRIX, &A));
53c4762a1bSJed Brown 
549566063dSJacob Faibussowitsch   PetscCall(MatEqual(C, A, &equal));
5528b400f6SJacob Faibussowitsch   PetscCheck(equal, PETSC_COMM_SELF, PETSC_ERR_SUP, "C != C^T");
56c4762a1bSJed Brown 
579566063dSJacob Faibussowitsch   PetscCall(MatDestroy(&C));
589566063dSJacob Faibussowitsch   PetscCall(MatDestroy(&A));
599566063dSJacob Faibussowitsch   PetscCall(PetscFinalize());
60b122ec5aSJacob Faibussowitsch   return 0;
61c4762a1bSJed Brown }
62c4762a1bSJed Brown 
63c4762a1bSJed Brown /*TEST
64c4762a1bSJed Brown 
65c4762a1bSJed Brown    test:
66c4762a1bSJed Brown 
67c4762a1bSJed Brown TEST*/
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