Actual source code: ex130.c


  2: static char help[] = "Tests external direct solvers. Simplified from ex125.c\n\
  3: Example: mpiexec -n <np> ./ex130 -f <matrix binary file> -mat_solver_type 1 -mat_superlu_equil \n\n";

  5: #include <petscmat.h>

  7: int main(int argc, char **args)
  8: {
  9:   Mat           A, F;
 10:   Vec           u, x, b;
 11:   PetscMPIInt   rank, size;
 12:   PetscInt      m, n, nfact, ipack = 0;
 13:   PetscReal     norm, tol = 1.e-12, Anorm;
 14:   IS            perm, iperm;
 15:   MatFactorInfo info;
 16:   PetscBool     flg, testMatSolve = PETSC_TRUE;
 17:   PetscViewer   fd;                       /* viewer */
 18:   char          file[PETSC_MAX_PATH_LEN]; /* input file name */

 20:   PetscFunctionBeginUser;
 21:   PetscCall(PetscInitialize(&argc, &args, (char *)0, help));
 22:   PetscCallMPI(MPI_Comm_rank(PETSC_COMM_WORLD, &rank));
 23:   PetscCallMPI(MPI_Comm_size(PETSC_COMM_WORLD, &size));

 25:   /* Determine file from which we read the matrix A */
 26:   PetscCall(PetscOptionsGetString(NULL, NULL, "-f", file, sizeof(file), &flg));
 27:   PetscCheck(flg, PETSC_COMM_WORLD, PETSC_ERR_USER, "Must indicate binary file with the -f option");

 29:   /* Load matrix A */
 30:   PetscCall(PetscViewerBinaryOpen(PETSC_COMM_WORLD, file, FILE_MODE_READ, &fd));
 31:   PetscCall(MatCreate(PETSC_COMM_WORLD, &A));
 32:   PetscCall(MatLoad(A, fd));
 33:   PetscCall(VecCreate(PETSC_COMM_WORLD, &b));
 34:   PetscCall(VecLoad(b, fd));
 35:   PetscCall(PetscViewerDestroy(&fd));
 36:   PetscCall(MatGetLocalSize(A, &m, &n));
 37:   PetscCheck(m == n, PETSC_COMM_SELF, PETSC_ERR_ARG_SIZ, "This example is not intended for rectangular matrices (%d, %d)", m, n);
 38:   PetscCall(MatNorm(A, NORM_INFINITY, &Anorm));

 40:   /* Create vectors */
 41:   PetscCall(VecDuplicate(b, &x));
 42:   PetscCall(VecDuplicate(x, &u)); /* save the true solution */

 44:   /* Test LU Factorization */
 45:   PetscCall(MatGetOrdering(A, MATORDERINGNATURAL, &perm, &iperm));

 47:   PetscCall(PetscOptionsGetInt(NULL, NULL, "-mat_solver_type", &ipack, NULL));
 48:   switch (ipack) {
 49:   case 1:
 50: #if defined(PETSC_HAVE_SUPERLU)
 51:     if (rank == 0) printf(" SUPERLU LU:\n");
 52:     PetscCall(MatGetFactor(A, MATSOLVERSUPERLU, MAT_FACTOR_LU, &F));
 53:     break;
 54: #endif
 55:   case 2:
 56: #if defined(PETSC_HAVE_MUMPS)
 57:     if (rank == 0) printf(" MUMPS LU:\n");
 58:     PetscCall(MatGetFactor(A, MATSOLVERMUMPS, MAT_FACTOR_LU, &F));
 59:     {
 60:       /* test mumps options */
 61:       PetscInt icntl_7 = 5;
 62:       PetscCall(MatMumpsSetIcntl(F, 7, icntl_7));
 63:     }
 64:     break;
 65: #endif
 66:   default:
 67:     if (rank == 0) printf(" PETSC LU:\n");
 68:     PetscCall(MatGetFactor(A, MATSOLVERPETSC, MAT_FACTOR_LU, &F));
 69:   }

 71:   info.fill = 5.0;
 72:   PetscCall(MatLUFactorSymbolic(F, A, perm, iperm, &info));

 74:   for (nfact = 0; nfact < 1; nfact++) {
 75:     if (rank == 0) printf(" %d-the LU numfactorization \n", nfact);
 76:     PetscCall(MatLUFactorNumeric(F, A, &info));

 78:     /* Test MatSolve() */
 79:     if (testMatSolve) {
 80:       PetscCall(MatSolve(F, b, x));

 82:       /* Check the residual */
 83:       PetscCall(MatMult(A, x, u));
 84:       PetscCall(VecAXPY(u, -1.0, b));
 85:       PetscCall(VecNorm(u, NORM_INFINITY, &norm));
 86:       if (norm > tol) {
 87:         if (rank == 0) PetscCall(PetscPrintf(PETSC_COMM_SELF, "MatSolve: rel residual %g/%g = %g, LU numfact %d\n", norm, Anorm, norm / Anorm, nfact));
 88:       }
 89:     }
 90:   }

 92:   /* Free data structures */
 93:   PetscCall(MatDestroy(&A));
 94:   PetscCall(MatDestroy(&F));
 95:   PetscCall(ISDestroy(&perm));
 96:   PetscCall(ISDestroy(&iperm));
 97:   PetscCall(VecDestroy(&x));
 98:   PetscCall(VecDestroy(&b));
 99:   PetscCall(VecDestroy(&u));
100:   PetscCall(PetscFinalize());
101:   return 0;
102: }