MueLu_PreserveDirichletAggregationAlgorithm_def.hpp

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#ifndef MUELU_PRESERVEDIRICHLETAGGREGATIONALGORITHM_DEF_HPP_
#define MUELU_PRESERVEDIRICHLETAGGREGATIONALGORITHM_DEF_HPP_

#include <Teuchos_Comm.hpp>
#include <Teuchos_CommHelpers.hpp>

#include <Xpetra_Vector.hpp>

#include "MueLu_PreserveDirichletAggregationAlgorithm.hpp"

#include "MueLu_GraphBase.hpp"
#include "MueLu_Aggregates.hpp"
#include "MueLu_Exceptions.hpp"
#include "MueLu_Monitor.hpp"

namespace MueLu {

  template <class LocalOrdinal, class GlobalOrdinal, class Node>
  void PreserveDirichletAggregationAlgorithm<LocalOrdinal, GlobalOrdinal, Node>::BuildAggregates(Teuchos::ParameterList const & params, GraphBase const & graph, Aggregates & aggregates, std::vector<unsigned>& aggStat, LO& numNonAggregatedNodes) const {
    Monitor m(*this, "BuildAggregates");

    bool preserve = params.get<bool>("aggregation: preserve Dirichlet points");

    const LO  numRows = graph.GetNodeNumVertices();
    const int myRank  = graph.GetComm()->getRank();

    ArrayRCP<LO> vertex2AggId = aggregates.GetVertex2AggId()->getDataNonConst(0);
    ArrayRCP<LO> procWinner   = aggregates.GetProcWinner()  ->getDataNonConst(0);

    LO numLocalAggregates = aggregates.GetNumAggregates();

    for (LO i = 0; i < numRows; i++)
      if (aggStat[i] == BOUNDARY) {
        aggStat[i] = IGNORED;
        numNonAggregatedNodes--;

        if (preserve) {
          aggregates.SetIsRoot(i);

          vertex2AggId[i] = numLocalAggregates++;
          procWinner  [i] = myRank;
        }
      }

    // update aggregate object
    aggregates.SetNumAggregates(numLocalAggregates);
  }

} // end namespace

#endif /* MUELU_PRESERVEDIRICHLETAGGREGATIONALGORITHM_DEF_HPP_ */