xref: /petsc/src/mat/tests/ex130.c (revision 732aec7a18f2199fb53bb9a2f3aef439a834ce31)
1 static char help[] = "Tests external direct solvers. Simplified from ex125.c\n\
2 Example: mpiexec -n <np> ./ex130 -f <matrix binary file> -mat_solver_type 1 -mat_superlu_equil \n\n";
3 
4 #include <petscmat.h>
5 
main(int argc,char ** args)6 int main(int argc, char **args)
7 {
8   Mat           A, F;
9   Vec           u, x, b;
10   PetscMPIInt   rank, size;
11   PetscInt      m, n, nfact, ipack = 0;
12   PetscReal     norm, tol = 1.e-12, Anorm;
13   IS            perm, iperm;
14   MatFactorInfo info;
15   PetscBool     flg, testMatSolve = PETSC_TRUE;
16   PetscViewer   fd;                       /* viewer */
17   char          file[PETSC_MAX_PATH_LEN]; /* input file name */
18 
19   PetscFunctionBeginUser;
20   PetscCall(PetscInitialize(&argc, &args, NULL, help));
21   PetscCallMPI(MPI_Comm_rank(PETSC_COMM_WORLD, &rank));
22   PetscCallMPI(MPI_Comm_size(PETSC_COMM_WORLD, &size));
23 
24   /* Determine file from which we read the matrix A */
25   PetscCall(PetscOptionsGetString(NULL, NULL, "-f", file, sizeof(file), &flg));
26   PetscCheck(flg, PETSC_COMM_WORLD, PETSC_ERR_USER, "Must indicate binary file with the -f option");
27 
28   /* Load matrix A */
29   PetscCall(PetscViewerBinaryOpen(PETSC_COMM_WORLD, file, FILE_MODE_READ, &fd));
30   PetscCall(MatCreate(PETSC_COMM_WORLD, &A));
31   PetscCall(MatLoad(A, fd));
32   PetscCall(VecCreate(PETSC_COMM_WORLD, &b));
33   PetscCall(VecLoad(b, fd));
34   PetscCall(PetscViewerDestroy(&fd));
35   PetscCall(MatGetLocalSize(A, &m, &n));
36   PetscCheck(m == n, PETSC_COMM_SELF, PETSC_ERR_ARG_SIZ, "This example is not intended for rectangular matrices (%d, %d)", m, n);
37   PetscCall(MatNorm(A, NORM_INFINITY, &Anorm));
38 
39   /* Create vectors */
40   PetscCall(VecDuplicate(b, &x));
41   PetscCall(VecDuplicate(x, &u)); /* save the true solution */
42 
43   /* Test LU Factorization */
44   PetscCall(MatGetOrdering(A, MATORDERINGNATURAL, &perm, &iperm));
45 
46   PetscCall(PetscOptionsGetInt(NULL, NULL, "-mat_solver_type", &ipack, NULL));
47   switch (ipack) {
48   case 1:
49 #if defined(PETSC_HAVE_SUPERLU)
50     if (rank == 0) printf(" SUPERLU LU:\n");
51     PetscCall(MatGetFactor(A, MATSOLVERSUPERLU, MAT_FACTOR_LU, &F));
52     break;
53 #endif
54   case 2:
55 #if defined(PETSC_HAVE_MUMPS)
56     if (rank == 0) printf(" MUMPS LU:\n");
57     PetscCall(MatGetFactor(A, MATSOLVERMUMPS, MAT_FACTOR_LU, &F));
58     {
59       /* test mumps options */
60       PetscInt icntl_7 = 5;
61       PetscCall(MatMumpsSetIcntl(F, 7, icntl_7));
62     }
63     break;
64 #endif
65   default:
66     if (rank == 0) printf(" PETSC LU:\n");
67     PetscCall(MatGetFactor(A, MATSOLVERPETSC, MAT_FACTOR_LU, &F));
68   }
69 
70   info.fill = 5.0;
71   PetscCall(MatLUFactorSymbolic(F, A, perm, iperm, &info));
72 
73   for (nfact = 0; nfact < 1; nfact++) {
74     if (rank == 0) printf(" %d-the LU numfactorization \n", nfact);
75     PetscCall(MatLUFactorNumeric(F, A, &info));
76 
77     /* Test MatSolve() */
78     if (testMatSolve) {
79       PetscCall(MatSolve(F, b, x));
80 
81       /* Check the residual */
82       PetscCall(MatMult(A, x, u));
83       PetscCall(VecAXPY(u, -1.0, b));
84       PetscCall(VecNorm(u, NORM_INFINITY, &norm));
85       if (norm > tol) {
86         if (rank == 0) PetscCall(PetscPrintf(PETSC_COMM_SELF, "MatSolve: rel residual %g/%g = %g, LU numfact %d\n", norm, Anorm, norm / Anorm, nfact));
87       }
88     }
89   }
90 
91   /* Free data structures */
92   PetscCall(MatDestroy(&A));
93   PetscCall(MatDestroy(&F));
94   PetscCall(ISDestroy(&perm));
95   PetscCall(ISDestroy(&iperm));
96   PetscCall(VecDestroy(&x));
97   PetscCall(VecDestroy(&b));
98   PetscCall(VecDestroy(&u));
99   PetscCall(PetscFinalize());
100   return 0;
101 }
102