MueLu_UserAggregationFactory_def.hpp

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// @HEADER
// *****************************************************************************
//        MueLu: A package for multigrid based preconditioning
//
// Copyright 2012 NTESS and the MueLu contributors.
// SPDX-License-Identifier: BSD-3-Clause
// *****************************************************************************
// @HEADER
 
#ifndef MUELU_USERAGGREGATIONFACTORY_DEF_HPP_
#define MUELU_USERAGGREGATIONFACTORY_DEF_HPP_
 
#include <Xpetra_Map.hpp>
#include <Xpetra_Vector.hpp>
#include <Xpetra_MultiVectorFactory.hpp>
#include <Xpetra_VectorFactory.hpp>
#include <Xpetra_MapFactory.hpp>
 
#include "MueLu_UserAggregationFactory_decl.hpp"
 
#include "MueLu_Level.hpp"
#include "MueLu_Aggregates.hpp"
#include "MueLu_Monitor.hpp"
 
namespace MueLu {
 
template <class LocalOrdinal, class GlobalOrdinal, class Node>
RCP<const ParameterList> UserAggregationFactory<LocalOrdinal, GlobalOrdinal, Node>::GetValidParameterList() const {
  RCP<ParameterList> validParamList = rcp(new ParameterList());
 
  // input parameters
  validParamList->set<std::string>("filePrefix", "", "The data is read from files of this name: <filePrefix><level>_<PID>.<fileExt>");
  validParamList->set<std::string>("fileExt", "", "The data is read from files of this name: <filePrefix><level>_<PID>.<fileExt>");
 
  return validParamList;
}
 
template <class LocalOrdinal, class GlobalOrdinal, class Node>
void UserAggregationFactory<LocalOrdinal, GlobalOrdinal, Node>::DeclareInput(Level& /* currentLevel */) const {}
 
template <class LocalOrdinal, class GlobalOrdinal, class Node>
void UserAggregationFactory<LocalOrdinal, GlobalOrdinal, Node>::Build(Level& currentLevel) const {
  FactoryMonitor m(*this, "Build", currentLevel);
 
  const ParameterList& pL = GetParameterList();
 
  RCP<const Teuchos::Comm<int> > comm = Teuchos::DefaultComm<int>::getComm();
  const int myRank                    = comm->getRank();
 
  std::string fileName = pL.get<std::string>("filePrefix") + toString(currentLevel.GetLevelID()) + "_" + toString(myRank) + "." + pL.get<std::string>("fileExt");
  std::ifstream ifs(fileName.c_str());
  TEUCHOS_TEST_FOR_EXCEPTION(!ifs.good(), Exceptions::RuntimeError, "Cannot read data from \"" << fileName << "\"");
 
  LO numVertices, numAggregates;
  ifs >> numVertices;
  TEUCHOS_TEST_FOR_EXCEPTION(!ifs.good(), Exceptions::RuntimeError, "Cannot read data from \"" << fileName << "\"");
  ifs >> numAggregates;
  TEUCHOS_TEST_FOR_EXCEPTION(numVertices <= 0, Exceptions::InvalidArgument, "Number of vertices   must be > 0");
  TEUCHOS_TEST_FOR_EXCEPTION(numAggregates <= 0, Exceptions::InvalidArgument, "Number of aggregates must be > 0");
 
  Xpetra::UnderlyingLib lib = currentLevel.lib();
  const int indexBase       = 0;
  RCP<Map> map              = MapFactory::Build(lib, numVertices, indexBase, comm);
 
  RCP<Aggregates> aggregates = rcp(new Aggregates(map));
  aggregates->setObjectLabel("User");
 
  aggregates->SetNumAggregates(numAggregates);
 
  Teuchos::ArrayRCP<LO> vertex2AggId = aggregates->GetVertex2AggId()->getDataNonConst(0);
  Teuchos::ArrayRCP<LO> procWinner   = aggregates->GetProcWinner()->getDataNonConst(0);
 
  for (LO i = 0; i < numAggregates; i++) {
    int aggSize = 0;
    ifs >> aggSize;
 
    std::vector<LO> list(aggSize);
    for (int k = 0; k < aggSize; k++) {
      // FIXME: File contains GIDs, we need LIDs
      // for now, works on a single processor
      ifs >> list[k];
    }
 
    // Mark first node as root node for the aggregate
    aggregates->SetIsRoot(list[0]);
 
    // Fill vertex2AggId and procWinner structure with information
    for (int k = 0; k < aggSize; k++) {
      vertex2AggId[list[k]] = i;
      procWinner[list[k]]   = myRank;
    }
  }
 
  // FIXME: do the proper check whether aggregates cross interprocessor boundary
  aggregates->AggregatesCrossProcessors(false);
 
  Set(currentLevel, "Aggregates", aggregates);
 
  GetOStream(Statistics0) << aggregates->description() << std::endl;
}
 
}  // namespace MueLu
 
#endif /* MUELU_USERAGGREGATIONFACTORY_DEF_HPP_ */