MueLu_AmalgamationInfo_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

/*
 * MueLu_AmalgamationInfo_def.hpp
 *
 *  Created on: Mar 28, 2012
 *      Author: wiesner
 */

#ifndef MUELU_AMALGAMATIONINFO_DEF_HPP_
#define MUELU_AMALGAMATIONINFO_DEF_HPP_

#include <Xpetra_MapFactory.hpp>
#include <Xpetra_Vector.hpp>

#include "MueLu_AmalgamationInfo_decl.hpp"
#include "MueLu_Exceptions.hpp"

#include "MueLu_Aggregates.hpp"

namespace MueLu {

template <class LocalOrdinal, class GlobalOrdinal, class Node>
void AmalgamationInfo<LocalOrdinal, GlobalOrdinal, Node>::
    UnamalgamateAggregates(const Aggregates &aggregates,
                           Teuchos::ArrayRCP<LocalOrdinal> &aggStart,
                           Teuchos::ArrayRCP<GlobalOrdinal> &aggToRowMap) const {
  UnamalgamateAggregates(aggregates.GetMap(),
                         aggregates.GetProcWinner(),
                         aggregates.GetVertex2AggId(),
                         aggregates.GetNumAggregates(),
                         aggStart,
                         aggToRowMap);

}  // UnamalgamateAggregates

template <class LocalOrdinal, class GlobalOrdinal, class Node>
void AmalgamationInfo<LocalOrdinal, GlobalOrdinal, Node>::
    UnamalgamateAggregates(const Teuchos::RCP<const Map> &nodeMap,
                           const RCP<LOVector> &procWinnerVec,
                           const RCP<LOMultiVector> &vertex2AggIdVec,
                           const GO numAggregates,
                           Teuchos::ArrayRCP<LocalOrdinal> &aggStart,
                           Teuchos::ArrayRCP<GlobalOrdinal> &aggToRowMap) const {
  int myPid                                   = nodeMap->getComm()->getRank();
  Teuchos::ArrayView<const GO> nodeGlobalElts = nodeMap->getLocalElementList();
  Teuchos::ArrayRCP<LO> procWinner            = procWinnerVec->getDataNonConst(0);
  Teuchos::ArrayRCP<LO> vertex2AggId          = vertex2AggIdVec->getDataNonConst(0);
  const LO size                               = procWinner.size();

  std::vector<LO> sizes(numAggregates);
  if (stridedblocksize_ == 1) {
    for (LO lnode = 0; lnode < size; ++lnode) {
      LO myAgg = vertex2AggId[lnode];
      if (procWinner[lnode] == myPid)
        sizes[myAgg] += 1;
    }
  } else {
    for (LO lnode = 0; lnode < size; ++lnode) {
      LO myAgg = vertex2AggId[lnode];
      if (procWinner[lnode] == myPid) {
        GO gnodeid = nodeGlobalElts[lnode];
        for (LocalOrdinal k = 0; k < stridedblocksize_; k++) {
          GlobalOrdinal gDofIndex = ComputeGlobalDOF(gnodeid, k);
          if (columnMap_->isNodeGlobalElement(gDofIndex))
            sizes[myAgg] += 1;
        }
      }
    }
  }
  aggStart    = ArrayRCP<LO>(numAggregates + 1, 0);
  aggStart[0] = Teuchos::ScalarTraits<LO>::zero();
  for (GO i = 0; i < numAggregates; ++i) {
    aggStart[i + 1] = aggStart[i] + sizes[i];
  }
  aggToRowMap = ArrayRCP<GO>(aggStart[numAggregates], 0);

  // count, how many dofs have been recorded for each aggregate so far
  Array<LO> numDofs(numAggregates, 0);  // empty array with number of Dofs for each aggregate

  if (stridedblocksize_ == 1) {
    for (LO lnode = 0; lnode < size; ++lnode) {
      LO myAgg = vertex2AggId[lnode];
      if (procWinner[lnode] == myPid) {
        aggToRowMap[aggStart[myAgg] + numDofs[myAgg]] = ComputeGlobalDOF(nodeGlobalElts[lnode]);
        ++(numDofs[myAgg]);
      }
    }
  } else {
    for (LO lnode = 0; lnode < size; ++lnode) {
      LO myAgg = vertex2AggId[lnode];

      if (procWinner[lnode] == myPid) {
        GO gnodeid = nodeGlobalElts[lnode];
        for (LocalOrdinal k = 0; k < stridedblocksize_; k++) {
          GlobalOrdinal gDofIndex = ComputeGlobalDOF(gnodeid, k);
          if (columnMap_->isNodeGlobalElement(gDofIndex)) {
            aggToRowMap[aggStart[myAgg] + numDofs[myAgg]] = gDofIndex;
            ++(numDofs[myAgg]);
          }
        }
      }
    }
  }
  // todo plausibility check: entry numDofs[k] == aggToRowMap[k].size()

}  // UnamalgamateAggregates

template <class LocalOrdinal, class GlobalOrdinal, class Node>
void AmalgamationInfo<LocalOrdinal, GlobalOrdinal, Node>::
    UnamalgamateAggregatesLO(const Aggregates &aggregates,
                             Teuchos::ArrayRCP<LO> &aggStart,
                             Teuchos::ArrayRCP<LO> &aggToRowMap) const {
  UnamalgamateAggregatesLO(aggregates.GetMap(),
                           aggregates.GetProcWinner(),
                           aggregates.GetVertex2AggId(),
                           aggregates.GetNumAggregates(),
                           aggStart,
                           aggToRowMap);
}

template <class LocalOrdinal, class GlobalOrdinal, class Node>
void AmalgamationInfo<LocalOrdinal, GlobalOrdinal, Node>::
    UnamalgamateAggregatesLO(const Teuchos::RCP<const Map> &nodeMap,
                             const RCP<LOVector> &procWinnerVec,
                             const RCP<LOMultiVector> &vertex2AggIdVec,
                             const GO numAggregates,
                             Teuchos::ArrayRCP<LO> &aggStart,
                             Teuchos::ArrayRCP<LO> &aggToRowMap) const {
  int myPid                                   = nodeMap->getComm()->getRank();
  Teuchos::ArrayView<const GO> nodeGlobalElts = nodeMap->getLocalElementList();

  Teuchos::ArrayRCP<LO> procWinner   = procWinnerVec->getDataNonConst(0);
  Teuchos::ArrayRCP<LO> vertex2AggId = vertex2AggIdVec->getDataNonConst(0);

  // FIXME: Do we need to compute size here? Or can we use existing?
  const LO size = procWinner.size();

  std::vector<LO> sizes(numAggregates);
  if (stridedblocksize_ == 1) {
    for (LO lnode = 0; lnode < size; lnode++)
      if (procWinner[lnode] == myPid)
        sizes[vertex2AggId[lnode]]++;
  } else {
    for (LO lnode = 0; lnode < size; lnode++)
      if (procWinner[lnode] == myPid) {
        GO nodeGID = nodeGlobalElts[lnode];

        for (LO k = 0; k < stridedblocksize_; k++) {
          GO GID = ComputeGlobalDOF(nodeGID, k);
          if (columnMap_->isNodeGlobalElement(GID))
            sizes[vertex2AggId[lnode]]++;
        }
      }
  }

  aggStart    = ArrayRCP<LO>(numAggregates + 1);  // FIXME: useless initialization with zeros
  aggStart[0] = 0;
  for (GO i = 0; i < numAggregates; i++)
    aggStart[i + 1] = aggStart[i] + sizes[i];

  aggToRowMap = ArrayRCP<LO>(aggStart[numAggregates], 0);

  // count, how many dofs have been recorded for each aggregate so far
  Array<LO> numDofs(numAggregates, 0);  // empty array with number of DOFs for each aggregate
  if (stridedblocksize_ == 1) {
    for (LO lnode = 0; lnode < size; ++lnode)
      if (procWinner[lnode] == myPid) {
        LO myAgg                                      = vertex2AggId[lnode];
        aggToRowMap[aggStart[myAgg] + numDofs[myAgg]] = lnode;
        numDofs[myAgg]++;
      }
  } else {
    for (LO lnode = 0; lnode < size; ++lnode)
      if (procWinner[lnode] == myPid) {
        LO myAgg   = vertex2AggId[lnode];
        GO nodeGID = nodeGlobalElts[lnode];

        for (LO k = 0; k < stridedblocksize_; k++) {
          GO GID = ComputeGlobalDOF(nodeGID, k);
          if (columnMap_->isNodeGlobalElement(GID)) {
            aggToRowMap[aggStart[myAgg] + numDofs[myAgg]] = lnode * stridedblocksize_ + k;
            numDofs[myAgg]++;
          }
        }
      }
  }
  // todo plausibility check: entry numDofs[k] == aggToRowMap[k].size()

}  // UnamalgamateAggregatesLO

template <class LocalOrdinal, class GlobalOrdinal, class Node>
void AmalgamationInfo<LocalOrdinal, GlobalOrdinal, Node>::print(Teuchos::FancyOStream &out,
                                                                const VerbLevel verbLevel) const {
  if (!(verbLevel & Debug))
    return;

  out << "AmalgamationInfo -- Striding information:"
      << "\n  fullBlockSize = " << fullblocksize_
      << "\n  blockID = " << blockid_
      << "\n  stridingOffset = " << nStridedOffset_
      << "\n  stridedBlockSize = " << stridedblocksize_
      << "\n  indexBase = " << indexBase_
      << std::endl;

  out << "AmalgamationInfo -- DOFs to nodes mapping:\n"
      << "  Mapping of row DOFs to row nodes:" << *rowTranslation_()
      << "\n\n  Mapping of column DOFs to column nodes:" << *colTranslation_()
      << std::endl;

  out << "AmalgamationInfo -- row node map:" << std::endl;
  nodeRowMap_->describe(out, Teuchos::VERB_EXTREME);

  out << "AmalgamationInfo -- column node map:" << std::endl;
  nodeColMap_->describe(out, Teuchos::VERB_EXTREME);
}


template <class LocalOrdinal, class GlobalOrdinal, class Node>
RCP<Xpetra::Map<LocalOrdinal, GlobalOrdinal, Node> > AmalgamationInfo<LocalOrdinal, GlobalOrdinal, Node>::
    ComputeUnamalgamatedImportDofMap(const Aggregates &aggregates) const {
  return ComputeUnamalgamatedImportDofMap(aggregates.GetMap());
}

template <class LocalOrdinal, class GlobalOrdinal, class Node>
RCP<Xpetra::Map<LocalOrdinal, GlobalOrdinal, Node> > AmalgamationInfo<LocalOrdinal, GlobalOrdinal, Node>::
    ComputeUnamalgamatedImportDofMap(const Teuchos::RCP<const Map> &nodeMap) const {
  Teuchos::RCP<std::vector<GO> > myDofGids = Teuchos::rcp(new std::vector<GO>);
  Teuchos::ArrayView<const GO> gEltList    = nodeMap->getLocalElementList();
  LO nodeElements                          = Teuchos::as<LO>(nodeMap->getLocalNumElements());
  if (stridedblocksize_ == 1) {
    for (LO n = 0; n < nodeElements; n++) {
      GlobalOrdinal gDofIndex = ComputeGlobalDOF(gEltList[n]);
      myDofGids->push_back(gDofIndex);
    }
  } else {
    for (LO n = 0; n < nodeElements; n++) {
      for (LocalOrdinal k = 0; k < stridedblocksize_; k++) {
        GlobalOrdinal gDofIndex = ComputeGlobalDOF(gEltList[n], k);
        if (columnMap_->isNodeGlobalElement(gDofIndex))
          myDofGids->push_back(gDofIndex);
      }
    }
  }

  Teuchos::ArrayRCP<GO> arr_myDofGids = Teuchos::arcp(myDofGids);
  Teuchos::RCP<Map> importDofMap      = MapFactory::Build(nodeMap->lib(), Teuchos::OrdinalTraits<Xpetra::global_size_t>::invalid(), arr_myDofGids(), nodeMap->getIndexBase(), nodeMap->getComm());
  return importDofMap;
}


template <class LocalOrdinal, class GlobalOrdinal, class Node>
GlobalOrdinal AmalgamationInfo<LocalOrdinal, GlobalOrdinal, Node>::
    ComputeGlobalDOF(GlobalOrdinal const &gNodeID, LocalOrdinal const &k) const {
  // here, the assumption is, that the node map has the same indexBase as the dof map
  //                            this is the node map index base                    this is the dof map index base
  GlobalOrdinal gDofIndex = offset_ + (gNodeID - indexBase_) * fullblocksize_ + nStridedOffset_ + k + indexBase_;
  return gDofIndex;
}

template <class LocalOrdinal, class GlobalOrdinal, class Node>
LocalOrdinal AmalgamationInfo<LocalOrdinal, GlobalOrdinal, Node>::ComputeLocalDOF(LocalOrdinal const &lNodeID, LocalOrdinal const &k) const {
  LocalOrdinal lDofIndex = lNodeID * fullblocksize_ + k;
  return lDofIndex;
}

template <class LocalOrdinal, class GlobalOrdinal, class Node>
LocalOrdinal AmalgamationInfo<LocalOrdinal, GlobalOrdinal, Node>::ComputeLocalNode(LocalOrdinal const &ldofID) const {
  return (ldofID - ldofID % fullblocksize_) / fullblocksize_;
}

}  // namespace MueLu

#endif /* MUELU_AMALGAMATIONINFO_DEF_HPP_ */