pbilinearform.cpp

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// Copyright (c) 2010, Lawrence Livermore National Security, LLC. Produced at
// the Lawrence Livermore National Laboratory. LLNL-CODE-443211. All Rights
// reserved. See file COPYRIGHT for details.
//
// This file is part of the MFEM library. For more information and source code
// availability see http://mfem.googlecode.com.
//
// MFEM is free software; you can redistribute it and/or modify it under the
// terms of the GNU Lesser General Public License (as published by the Free
// Software Foundation) version 2.1 dated February 1999.

#ifdef MFEM_USE_MPI

#include "fem.hpp"

HypreParMatrix *ParBilinearForm::ParallelAssemble(SparseMatrix *m)
{
   if (m == NULL)
      return NULL;

   // construct a parallel block-diagonal wrapper matrix A based on m
   HypreParMatrix *A = new HypreParMatrix(pfes->GlobalVSize(),
                                          pfes->GetDofOffsets(), m);

   HypreParMatrix *rap = RAP(A, pfes->Dof_TrueDof_Matrix());

   delete A;

   return rap;
}

HypreParMatrix *ParDiscreteLinearOperator::ParallelAssemble(SparseMatrix *m)
{
   if (m == NULL)
      return NULL;

   int *I = m->GetI();
   int *J = m->GetJ();
   double *data = m->GetData();

   // remap to tdof local row and tdof global column indices
   SparseMatrix local(range_fes->TrueVSize(), domain_fes->GlobalTrueVSize());
   for (int i = 0; i < m->Size(); i++)
   {
      int lti = range_fes->GetLocalTDofNumber(i);
      if (lti >= 0)
         for (int j = I[i]; j < I[i+1]; j++)
            local.Set(lti, domain_fes->GetGlobalTDofNumber(J[j]), data[j]);
   }
   local.Finalize();

   // construct and return a global ParCSR matrix by splitting the local matrix
   // into diag and offd parts
   return new HypreParMatrix(range_fes->GetComm(),
                             range_fes->TrueVSize(),
                             range_fes->GlobalTrueVSize(),
                             domain_fes->GlobalTrueVSize(),
                             local.GetI(), local.GetJ(), local.GetData(),
                             range_fes->GetTrueDofOffsets(),
                             domain_fes->GetTrueDofOffsets());
}

void ParDiscreteLinearOperator::GetParBlocks(Array2D<HypreParMatrix *> &blocks) const
{
   int rdim = range_fes->GetVDim();
   int ddim = domain_fes->GetVDim();

   blocks.SetSize(rdim, ddim);

   int i, j, n;

   // construct the scalar versions of the row/coll offset arrays
   int *row_starts, *col_starts;
   if (HYPRE_AssumedPartitionCheck())
      n = 2;
   else
      n = range_fes->GetNRanks()+1;
   row_starts = new int[n];
   col_starts = new int[n];
   for (i = 0; i < n; i++)
   {
      row_starts[i] = (range_fes->GetTrueDofOffsets())[i] / rdim;
      col_starts[i] = (domain_fes->GetTrueDofOffsets())[i] / ddim;
   }

   Array2D<SparseMatrix *> lblocks;
   GetBlocks(lblocks);

   for (int bi = 0; bi < rdim; bi++)
      for (int bj = 0; bj < ddim; bj++)
      {
         int *I = lblocks(bi,bj)->GetI();
         int *J = lblocks(bi,bj)->GetJ();
         double *data = lblocks(bi,bj)->GetData();

         // remap to tdof local row and tdof global column indices
         SparseMatrix local(range_fes->TrueVSize()/rdim,
                            domain_fes->GlobalTrueVSize()/ddim);
         for (i = 0; i < lblocks(bi,bj)->Size(); i++)
         {
            int lti = range_fes->GetLocalTDofNumber(i);
            if (lti >= 0)
               for (j = I[i]; j < I[i+1]; j++)
                  local.Set(lti,
                            domain_fes->GetGlobalScalarTDofNumber(J[j]),
                            data[j]);
         }
         local.Finalize();

         delete lblocks(bi,bj);

         // construct and return a global ParCSR matrix by splitting the local
         // matrix into diag and offd parts
         blocks(bi,bj) = new HypreParMatrix(range_fes->GetComm(),
                                            range_fes->TrueVSize()/rdim,
                                            range_fes->GlobalTrueVSize()/rdim,
                                            domain_fes->GlobalTrueVSize()/ddim,
                                            local.GetI(), local.GetJ(), local.GetData(),
                                            row_starts, col_starts);
      }

   delete row_starts;
   delete col_starts;
}

#endif