HYPRE_Int
HYPRE_SStructFlexGMRESSetPrecond( HYPRE_SStructSolver          solver,
                              HYPRE_PtrToSStructSolverFcn  precond,
                              HYPRE_PtrToSStructSolverFcn  precond_setup,
                              void *          precond_data )
{
   return( HYPRE_FlexGMRESSetPrecond( (HYPRE_Solver) solver,
                                  (HYPRE_PtrToSolverFcn) precond,
                                  (HYPRE_PtrToSolverFcn) precond_setup,
                                  (HYPRE_Solver) precond_data ) );
}
Пример #2
0
 inline void numfact(unsigned int ncol, int* I, int* loc2glob, int* J, K* C) {
     static_assert(std::is_same<double, K>::value, "Hypre only supports double-precision floating-point real numbers");
     static_assert(S == 'G', "Hypre only supports nonsymmetric matrices");
     HYPRE_IJMatrixCreate(DMatrix::_communicator, loc2glob[0], loc2glob[1], loc2glob[0], loc2glob[1], &_A);
     HYPRE_IJMatrixSetObjectType(_A, HYPRE_PARCSR);
     HYPRE_IJMatrixSetRowSizes(_A, I + 1);
     _local = ncol;
     int* rows = new int[3 * _local]();
     int* diag_sizes = rows + _local;
     int* offdiag_sizes = diag_sizes + _local;
     rows[0] = I[0];
     for(unsigned int i = 0; i < _local; ++i) {
         std::for_each(J + rows[0], J + rows[0] + I[i + 1], [&](int& j) { (j < loc2glob[0] || loc2glob[1] < j) ? ++offdiag_sizes[i] : ++diag_sizes[i]; });
         rows[0] += I[i + 1];
     }
     HYPRE_IJMatrixSetDiagOffdSizes(_A, diag_sizes, offdiag_sizes);
     HYPRE_IJMatrixSetMaxOffProcElmts(_A, 0);
     HYPRE_IJMatrixInitialize(_A);
     std::iota(rows, rows + _local, loc2glob[0]);
     HYPRE_IJMatrixSetValues(_A, _local, I + 1, rows, J, C);
     HYPRE_IJMatrixAssemble(_A);
     HYPRE_IJVectorCreate(DMatrix::_communicator, loc2glob[0], loc2glob[1], &_b);
     HYPRE_IJVectorSetObjectType(_b, HYPRE_PARCSR);
     HYPRE_IJVectorInitialize(_b);
     HYPRE_IJVectorCreate(DMatrix::_communicator, loc2glob[0], loc2glob[1], &_x);
     HYPRE_IJVectorSetObjectType(_x, HYPRE_PARCSR);
     HYPRE_IJVectorInitialize(_x);
     delete [] rows;
     delete [] I;
     delete [] loc2glob;
     HYPRE_BoomerAMGCreate(_strategy == 1 ? &_solver : &_precond);
     HYPRE_BoomerAMGSetCoarsenType(_strategy == 1 ? _solver : _precond, 6); /* Falgout coarsening */
     HYPRE_BoomerAMGSetRelaxType(_strategy == 1 ? _solver : _precond, 6);   /* G-S/Jacobi hybrid relaxation */
     HYPRE_BoomerAMGSetNumSweeps(_strategy == 1 ? _solver : _precond, 1);   /* sweeps on each level */
     HYPRE_BoomerAMGSetMaxLevels(_strategy == 1 ? _solver : _precond, 10);  /* maximum number of levels */
     HYPRE_ParCSRMatrix parcsr_A;
     HYPRE_IJMatrixGetObject(_A, reinterpret_cast<void**>(&parcsr_A));
     HYPRE_ParVector par_b;
     HYPRE_IJVectorGetObject(_b, reinterpret_cast<void**>(&par_b));
     HYPRE_ParVector par_x;
     HYPRE_IJVectorGetObject(_x, reinterpret_cast<void**>(&par_x));
     if(_strategy == 1) {
         HYPRE_BoomerAMGSetTol(_solver, 1.0e-8);
         HYPRE_BoomerAMGSetMaxIter(_solver, 1000);
         HYPRE_BoomerAMGSetPrintLevel(_solver, 1);
         HYPRE_BoomerAMGSetup(_solver, parcsr_A, nullptr, nullptr);
     }
     else {
         HYPRE_BoomerAMGSetTol(_precond, 0.0);
         HYPRE_BoomerAMGSetMaxIter(_precond, 1);
         HYPRE_BoomerAMGSetPrintLevel(_precond, 1);
         if(_strategy == 2) {
             HYPRE_ParCSRPCGCreate(DMatrix::_communicator, &_solver);
             HYPRE_PCGSetMaxIter(_solver, 500);
             HYPRE_PCGSetTol(_solver, 1.0e-8);
             HYPRE_PCGSetTwoNorm(_solver, 1);
             HYPRE_PCGSetPrintLevel(_solver, 1);
             HYPRE_PCGSetLogging(_solver, 1);
             HYPRE_PCGSetPrecond(_solver, reinterpret_cast<HYPRE_PtrToSolverFcn>(HYPRE_BoomerAMGSolve), reinterpret_cast<HYPRE_PtrToSolverFcn>(HYPRE_BoomerAMGSetup), _precond);
             HYPRE_ParCSRPCGSetup(_solver, parcsr_A, par_b, par_x);
         }
         else {
             HYPRE_ParCSRFlexGMRESCreate(DMatrix::_communicator, &_solver);
             HYPRE_FlexGMRESSetKDim(_solver, 50);
             HYPRE_FlexGMRESSetMaxIter(_solver, 500);
             HYPRE_FlexGMRESSetTol(_solver, 1.0e-8);
             HYPRE_FlexGMRESSetPrintLevel(_solver, 1);
             HYPRE_FlexGMRESSetLogging(_solver, 1);
             HYPRE_FlexGMRESSetPrecond(_solver, reinterpret_cast<HYPRE_PtrToSolverFcn>(HYPRE_BoomerAMGSolve), reinterpret_cast<HYPRE_PtrToSolverFcn>(HYPRE_BoomerAMGSetup), _precond);
             HYPRE_ParCSRFlexGMRESSetup(_solver, parcsr_A, par_b, par_x);
         }
     }
 }
Пример #3
0
int main (int argc, char *argv[])
{
   HYPRE_Int i;
   int myid, num_procs;
   int N, n;

   HYPRE_Int ilower, iupper;
   HYPRE_Int local_size, extra;

   int solver_id;
   int print_solution, print_system;

   double h, h2;

   HYPRE_IJMatrix A;
   HYPRE_ParCSRMatrix parcsr_A;
   HYPRE_IJVector b;
   HYPRE_ParVector par_b;
   HYPRE_IJVector x;
   HYPRE_ParVector par_x;

   HYPRE_Solver solver, precond;

   /* Initialize MPI */
   MPI_Init(&argc, &argv);
   MPI_Comm_rank(MPI_COMM_WORLD, &myid);
   MPI_Comm_size(MPI_COMM_WORLD, &num_procs);

   /* Default problem parameters */
   n = 33;
   solver_id = 0;
   print_solution  = 0;
   print_system = 0;


   /* Parse command line */
   {
      int arg_index = 0;
      int print_usage = 0;

      while (arg_index < argc)
      {
         if ( strcmp(argv[arg_index], "-n") == 0 )
         {
            arg_index++;
            n = atoi(argv[arg_index++]);
         }
         else if ( strcmp(argv[arg_index], "-solver") == 0 )
         {
            arg_index++;
            solver_id = atoi(argv[arg_index++]);
         }
         else if ( strcmp(argv[arg_index], "-print_solution") == 0 )
         {
            arg_index++;
            print_solution = 1;
         }
         else if ( strcmp(argv[arg_index], "-print_system") == 0 )
         {
            arg_index++;
            print_system = 1;
         }


         else if ( strcmp(argv[arg_index], "-help") == 0 )
         {
            print_usage = 1;
            break;
         }
         else
         {
            arg_index++;
         }
      }

      if ((print_usage) && (myid == 0))
      {
         printf("\n");
         printf("Usage: %s [<options>]\n", argv[0]);
         printf("\n");
         printf("  -n <n>              : problem size in each direction (default: 33)\n");
         printf("  -solver <ID>        : solver ID\n");
         printf("                        0  - AMG (default) \n");
         printf("                        1  - AMG-PCG\n");
         printf("                        8  - ParaSails-PCG\n");
         printf("                        50 - PCG\n");
         printf("                        61 - AMG-FlexGMRES\n");
         printf("  -print_solution     : print the solution vector\n");
         printf("  -print_system       : print the matrix and rhs\n");
         printf("\n");
      }

      if (print_usage)
      {
         MPI_Finalize();
         return (0);
      }
   }

   /* Preliminaries: want at least one processor per row */
   if (n*n < num_procs) n = sqrt(num_procs) + 1;
   N = n*n; /* global number of rows */
   h = 1.0/(n+1); /* mesh size*/
   h2 = h*h;

   /* Each processor knows only of its own rows - the range is denoted by ilower
      and upper.  Here we partition the rows. We account for the fact that
      N may not divide evenly by the number of processors. */
   local_size = N/num_procs;
   extra = N - local_size*num_procs;

   ilower = local_size*myid;
   ilower += hypre_min(myid, extra);

   iupper = local_size*(myid+1);
   iupper += hypre_min(myid+1, extra);
   iupper = iupper - 1;

   /* How many rows do I have? */
   local_size = iupper - ilower + 1;

   /* Create the matrix.
      Note that this is a square matrix, so we indicate the row partition
      size twice (since number of rows = number of cols) */
   HYPRE_IJMatrixCreate(MPI_COMM_WORLD, ilower, iupper, ilower, iupper, &A);

   /* Choose a parallel csr format storage (see the User's Manual) */
   HYPRE_IJMatrixSetObjectType(A, HYPRE_PARCSR);

   /* Initialize before setting coefficients */
   HYPRE_IJMatrixInitialize(A);

   /* Now go through my local rows and set the matrix entries.
      Each row has at most 5 entries. For example, if n=3:

      A = [M -I 0; -I M -I; 0 -I M]
      M = [4 -1 0; -1 4 -1; 0 -1 4]

      Note that here we are setting one row at a time, though
      one could set all the rows together (see the User's Manual).
   */
   {
      HYPRE_Int nnz;
      double values[5];
      HYPRE_Int cols[5];

      for (i = ilower; i <= iupper; i++)
      {
         nnz = 0;

         /* The left identity block:position i-n */
         if ((i-n)>=0)
         {
            cols[nnz] = i-n;
            values[nnz] = -1.0;
            nnz++;
         }

         /* The left -1: position i-1 */
         if (i%n)
         {
            cols[nnz] = i-1;
            values[nnz] = -1.0;
            nnz++;
         }

         /* Set the diagonal: position i */
         cols[nnz] = i;
         values[nnz] = 4.0;
         nnz++;

         /* The right -1: position i+1 */
         if ((i+1)%n)
         {
            cols[nnz] = i+1;
            values[nnz] = -1.0;
            nnz++;
         }

         /* The right identity block:position i+n */
         if ((i+n)< N)
         {
            cols[nnz] = i+n;
            values[nnz] = -1.0;
            nnz++;
         }

         /* Set the values for row i */
         HYPRE_IJMatrixSetValues(A, 1, &nnz, &i, cols, values);
      }
   }

   /* Assemble after setting the coefficients */
   HYPRE_IJMatrixAssemble(A);

   /* Note: for the testing of small problems, one may wish to read
      in a matrix in IJ format (for the format, see the output files
      from the -print_system option).
      In this case, one would use the following routine:
      HYPRE_IJMatrixRead( <filename>, MPI_COMM_WORLD,
                          HYPRE_PARCSR, &A );
      <filename>  = IJ.A.out to read in what has been printed out
      by -print_system (processor numbers are omitted).
      A call to HYPRE_IJMatrixRead is an *alternative* to the
      following sequence of HYPRE_IJMatrix calls:
      Create, SetObjectType, Initialize, SetValues, and Assemble
   */


   /* Get the parcsr matrix object to use */
   HYPRE_IJMatrixGetObject(A, (void**) &parcsr_A);


   /* Create the rhs and solution */
   HYPRE_IJVectorCreate(MPI_COMM_WORLD, ilower, iupper,&b);
   HYPRE_IJVectorSetObjectType(b, HYPRE_PARCSR);
   HYPRE_IJVectorInitialize(b);

   HYPRE_IJVectorCreate(MPI_COMM_WORLD, ilower, iupper,&x);
   HYPRE_IJVectorSetObjectType(x, HYPRE_PARCSR);
   HYPRE_IJVectorInitialize(x);

   /* Set the rhs values to h^2 and the solution to zero */
   {
      double *rhs_values, *x_values;
      HYPRE_Int *rows;

      rhs_values = calloc(local_size, sizeof(double));
      x_values = calloc(local_size, sizeof(double));
      rows = calloc(local_size, sizeof(HYPRE_Int));

      for (i=0; i<local_size; i++)
      {
         rhs_values[i] = h2;
         x_values[i] = 0.0;
         rows[i] = ilower + i;
      }

      HYPRE_IJVectorSetValues(b, local_size, rows, rhs_values);
      HYPRE_IJVectorSetValues(x, local_size, rows, x_values);

      free(x_values);
      free(rhs_values);
      free(rows);
   }


   HYPRE_IJVectorAssemble(b);
   /*  As with the matrix, for testing purposes, one may wish to read in a rhs:
       HYPRE_IJVectorRead( <filename>, MPI_COMM_WORLD,
                                 HYPRE_PARCSR, &b );
       as an alternative to the
       following sequence of HYPRE_IJVectors calls:
       Create, SetObjectType, Initialize, SetValues, and Assemble
   */
   HYPRE_IJVectorGetObject(b, (void **) &par_b);

   HYPRE_IJVectorAssemble(x);
   HYPRE_IJVectorGetObject(x, (void **) &par_x);


  /*  Print out the system  - files names will be IJ.out.A.XXXXX
       and IJ.out.b.XXXXX, where XXXXX = processor id */
   if (print_system)
   {
      HYPRE_IJMatrixPrint(A, "IJ.out.A");
      HYPRE_IJVectorPrint(b, "IJ.out.b");
   }


   /* Choose a solver and solve the system */

   /* AMG */
   if (solver_id == 0)
   {
      HYPRE_Int num_iterations;
      double final_res_norm;

      /* Create solver */
      HYPRE_BoomerAMGCreate(&solver);

      /* Set some parameters (See Reference Manual for more parameters) */
      HYPRE_BoomerAMGSetPrintLevel(solver, 3);  /* print solve info + parameters */
      HYPRE_BoomerAMGSetCoarsenType(solver, 6); /* Falgout coarsening */
      HYPRE_BoomerAMGSetRelaxType(solver, 3);   /* G-S/Jacobi hybrid relaxation */
      HYPRE_BoomerAMGSetNumSweeps(solver, 1);   /* Sweeeps on each level */
      HYPRE_BoomerAMGSetMaxLevels(solver, 20);  /* maximum number of levels */
      HYPRE_BoomerAMGSetTol(solver, 1e-7);      /* conv. tolerance */

      /* Now setup and solve! */
      HYPRE_BoomerAMGSetup(solver, parcsr_A, par_b, par_x);
      HYPRE_BoomerAMGSolve(solver, parcsr_A, par_b, par_x);

      /* Run info - needed logging turned on */
      HYPRE_BoomerAMGGetNumIterations(solver, &num_iterations);
      HYPRE_BoomerAMGGetFinalRelativeResidualNorm(solver, &final_res_norm);
      if (myid == 0)
      {
         printf("\n");
         printf("Iterations = %lld\n", num_iterations);
         printf("Final Relative Residual Norm = %e\n", final_res_norm);
         printf("\n");
      }

      /* Destroy solver */
      HYPRE_BoomerAMGDestroy(solver);
   }
   /* PCG */
   else if (solver_id == 50)
   {
      HYPRE_Int num_iterations;
      double final_res_norm;

      /* Create solver */
      HYPRE_ParCSRPCGCreate(MPI_COMM_WORLD, &solver);

      /* Set some parameters (See Reference Manual for more parameters) */
      HYPRE_PCGSetMaxIter(solver, 1000); /* max iterations */
      HYPRE_PCGSetTol(solver, 1e-7); /* conv. tolerance */
      HYPRE_PCGSetTwoNorm(solver, 1); /* use the two norm as the stopping criteria */
      HYPRE_PCGSetPrintLevel(solver, 2); /* prints out the iteration info */
      HYPRE_PCGSetLogging(solver, 1); /* needed to get run info later */

      /* Now setup and solve! */
      HYPRE_ParCSRPCGSetup(solver, parcsr_A, par_b, par_x);
      HYPRE_ParCSRPCGSolve(solver, parcsr_A, par_b, par_x);

      /* Run info - needed logging turned on */
      HYPRE_PCGGetNumIterations(solver, &num_iterations);
      HYPRE_PCGGetFinalRelativeResidualNorm(solver, &final_res_norm);
      if (myid == 0)
      {
         printf("\n");
         printf("Iterations = %lld\n", num_iterations);
         printf("Final Relative Residual Norm = %e\n", final_res_norm);
         printf("\n");
      }

      /* Destroy solver */
      HYPRE_ParCSRPCGDestroy(solver);
   }
   /* PCG with AMG preconditioner */
   else if (solver_id == 1)
   {
      HYPRE_Int num_iterations;
      double final_res_norm;

      /* Create solver */
      HYPRE_ParCSRPCGCreate(MPI_COMM_WORLD, &solver);

      /* Set some parameters (See Reference Manual for more parameters) */
      HYPRE_PCGSetMaxIter(solver, 1000); /* max iterations */
      HYPRE_PCGSetTol(solver, 1e-7); /* conv. tolerance */
      HYPRE_PCGSetTwoNorm(solver, 1); /* use the two norm as the stopping criteria */
      HYPRE_PCGSetPrintLevel(solver, 2); /* print solve info */
      HYPRE_PCGSetLogging(solver, 1); /* needed to get run info later */

      /* Now set up the AMG preconditioner and specify any parameters */
      HYPRE_BoomerAMGCreate(&precond);
      HYPRE_BoomerAMGSetPrintLevel(precond, 1); /* print amg solution info */
      HYPRE_BoomerAMGSetCoarsenType(precond, 6);
      HYPRE_BoomerAMGSetRelaxType(precond, 6); /* Sym G.S./Jacobi hybrid */
      HYPRE_BoomerAMGSetNumSweeps(precond, 1);
      HYPRE_BoomerAMGSetTol(precond, 0.0); /* conv. tolerance zero */
      HYPRE_BoomerAMGSetMaxIter(precond, 1); /* do only one iteration! */

      /* Set the PCG preconditioner */
      HYPRE_PCGSetPrecond(solver, (HYPRE_PtrToSolverFcn) HYPRE_BoomerAMGSolve,
                          (HYPRE_PtrToSolverFcn) HYPRE_BoomerAMGSetup, precond);

      /* Now setup and solve! */
      HYPRE_ParCSRPCGSetup(solver, parcsr_A, par_b, par_x);
      HYPRE_ParCSRPCGSolve(solver, parcsr_A, par_b, par_x);

      /* Run info - needed logging turned on */
      HYPRE_PCGGetNumIterations(solver, &num_iterations);
      HYPRE_PCGGetFinalRelativeResidualNorm(solver, &final_res_norm);
      if (myid == 0)
      {
         printf("\n");
         printf("Iterations = %lld\n", num_iterations);
         printf("Final Relative Residual Norm = %e\n", final_res_norm);
         printf("\n");
      }

      /* Destroy solver and preconditioner */
      HYPRE_ParCSRPCGDestroy(solver);
      HYPRE_BoomerAMGDestroy(precond);
   }
   /* PCG with Parasails Preconditioner */
   else if (solver_id == 8)
   {
      HYPRE_Int num_iterations;
      double final_res_norm;

      int      sai_max_levels = 1;
      double   sai_threshold = 0.1;
      double   sai_filter = 0.05;
      int      sai_sym = 1;

      /* Create solver */
      HYPRE_ParCSRPCGCreate(MPI_COMM_WORLD, &solver);

      /* Set some parameters (See Reference Manual for more parameters) */
      HYPRE_PCGSetMaxIter(solver, 1000); /* max iterations */
      HYPRE_PCGSetTol(solver, 1e-7); /* conv. tolerance */
      HYPRE_PCGSetTwoNorm(solver, 1); /* use the two norm as the stopping criteria */
      HYPRE_PCGSetPrintLevel(solver, 2); /* print solve info */
      HYPRE_PCGSetLogging(solver, 1); /* needed to get run info later */

      /* Now set up the ParaSails preconditioner and specify any parameters */
      HYPRE_ParaSailsCreate(MPI_COMM_WORLD, &precond);

      /* Set some parameters (See Reference Manual for more parameters) */
      HYPRE_ParaSailsSetParams(precond, sai_threshold, sai_max_levels);
      HYPRE_ParaSailsSetFilter(precond, sai_filter);
      HYPRE_ParaSailsSetSym(precond, sai_sym);
      HYPRE_ParaSailsSetLogging(precond, 3);

      /* Set the PCG preconditioner */
      HYPRE_PCGSetPrecond(solver, (HYPRE_PtrToSolverFcn) HYPRE_ParaSailsSolve,
                          (HYPRE_PtrToSolverFcn) HYPRE_ParaSailsSetup, precond);

      /* Now setup and solve! */
      HYPRE_ParCSRPCGSetup(solver, parcsr_A, par_b, par_x);
      HYPRE_ParCSRPCGSolve(solver, parcsr_A, par_b, par_x);


      /* Run info - needed logging turned on */
      HYPRE_PCGGetNumIterations(solver, &num_iterations);
      HYPRE_PCGGetFinalRelativeResidualNorm(solver, &final_res_norm);
      if (myid == 0)
      {
         printf("\n");
         printf("Iterations = %lld\n", num_iterations);
         printf("Final Relative Residual Norm = %e\n", final_res_norm);
         printf("\n");
      }

      /* Destory solver and preconditioner */
      HYPRE_ParCSRPCGDestroy(solver);
      HYPRE_ParaSailsDestroy(precond);
   }
   /* Flexible GMRES with  AMG Preconditioner */
   else if (solver_id == 61)
   {
      HYPRE_Int num_iterations;
      double final_res_norm;
      int    restart = 30;
      int    modify = 1;


      /* Create solver */
      HYPRE_ParCSRFlexGMRESCreate(MPI_COMM_WORLD, &solver);

      /* Set some parameters (See Reference Manual for more parameters) */
      HYPRE_FlexGMRESSetKDim(solver, restart);
      HYPRE_FlexGMRESSetMaxIter(solver, 1000); /* max iterations */
      HYPRE_FlexGMRESSetTol(solver, 1e-7); /* conv. tolerance */
      HYPRE_FlexGMRESSetPrintLevel(solver, 2); /* print solve info */
      HYPRE_FlexGMRESSetLogging(solver, 1); /* needed to get run info later */


      /* Now set up the AMG preconditioner and specify any parameters */
      HYPRE_BoomerAMGCreate(&precond);
      HYPRE_BoomerAMGSetPrintLevel(precond, 1); /* print amg solution info */
      HYPRE_BoomerAMGSetCoarsenType(precond, 6);
      HYPRE_BoomerAMGSetRelaxType(precond, 6); /* Sym G.S./Jacobi hybrid */
      HYPRE_BoomerAMGSetNumSweeps(precond, 1);
      HYPRE_BoomerAMGSetTol(precond, 0.0); /* conv. tolerance zero */
      HYPRE_BoomerAMGSetMaxIter(precond, 1); /* do only one iteration! */

      /* Set the FlexGMRES preconditioner */
      HYPRE_FlexGMRESSetPrecond(solver, (HYPRE_PtrToSolverFcn) HYPRE_BoomerAMGSolve,
                          (HYPRE_PtrToSolverFcn) HYPRE_BoomerAMGSetup, precond);


      if (modify)
      /* this is an optional call  - if you don't call it, hypre_FlexGMRESModifyPCDefault
         is used - which does nothing.  Otherwise, you can define your own, similar to
         the one used here */
         HYPRE_FlexGMRESSetModifyPC( solver,
                                     (HYPRE_PtrToModifyPCFcn) hypre_FlexGMRESModifyPCAMGExample);


      /* Now setup and solve! */
      HYPRE_ParCSRFlexGMRESSetup(solver, parcsr_A, par_b, par_x);
      HYPRE_ParCSRFlexGMRESSolve(solver, parcsr_A, par_b, par_x);

      /* Run info - needed logging turned on */
      HYPRE_FlexGMRESGetNumIterations(solver, &num_iterations);
      HYPRE_FlexGMRESGetFinalRelativeResidualNorm(solver, &final_res_norm);
      if (myid == 0)
      {
         printf("\n");
         printf("Iterations = %lld\n", num_iterations);
         printf("Final Relative Residual Norm = %e\n", final_res_norm);
         printf("\n");
      }

      /* Destory solver and preconditioner */
      HYPRE_ParCSRFlexGMRESDestroy(solver);
      HYPRE_BoomerAMGDestroy(precond);

   }
   else
   {
      if (myid ==0) printf("Invalid solver id specified.\n");
   }

   /* Print the solution */
   if (print_solution)
      HYPRE_IJVectorPrint(x, "ij.out.x");

   /* Clean up */
   HYPRE_IJMatrixDestroy(A);
   HYPRE_IJVectorDestroy(b);
   HYPRE_IJVectorDestroy(x);

   /* Finalize MPI*/
   MPI_Finalize();

   return(0);
}