MueLu_MLParameterListInterpreter_def.hpp

Go to the documentation of this file.

// @HEADER
//
// ***********************************************************************
//
//        MueLu: A package for multigrid based preconditioning
//                  Copyright 2012 Sandia Corporation
//
// Under the terms of Contract DE-AC04-94AL85000 with Sandia Corporation,
// the U.S. Government retains certain rights in this software.
//
// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions are
// met:
//
// 1. Redistributions of source code must retain the above copyright
// notice, this list of conditions and the following disclaimer.
//
// 2. Redistributions in binary form must reproduce the above copyright
// notice, this list of conditions and the following disclaimer in the
// documentation and/or other materials provided with the distribution.
//
// 3. Neither the name of the Corporation nor the names of the
// contributors may be used to endorse or promote products derived from
// this software without specific prior written permission.
//
// THIS SOFTWARE IS PROVIDED BY SANDIA CORPORATION "AS IS" AND ANY
// EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
// IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
// PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL SANDIA CORPORATION OR THE
// CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
// EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
// PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
// PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
// LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
// NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
// SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
//
// Questions? Contact
//                    Jonathan Hu       (jhu@sandia.gov)
//                    Andrey Prokopenko (aprokop@sandia.gov)
//                    Ray Tuminaro      (rstumin@sandia.gov)
//
// ***********************************************************************
//
// @HEADER
#ifndef MUELU_MLPARAMETERLISTINTERPRETER_DEF_HPP
#define MUELU_MLPARAMETERLISTINTERPRETER_DEF_HPP
 
#include <Teuchos_XMLParameterListHelpers.hpp>
 
#include "MueLu_ConfigDefs.hpp"
#if defined(HAVE_MUELU_ML) && defined(HAVE_MUELU_EPETRA)
#include <ml_ValidateParameters.h>
#endif
 
#include <Xpetra_Matrix.hpp>
#include <Xpetra_MultiVector.hpp>
#include <Xpetra_MultiVectorFactory.hpp>
#include <Xpetra_Operator.hpp>
 
#include "MueLu_MLParameterListInterpreter_decl.hpp"
 
#include "MueLu_Level.hpp"
#include "MueLu_Hierarchy.hpp"
#include "MueLu_FactoryManager.hpp"
 
#include "MueLu_TentativePFactory.hpp"
#include "MueLu_SaPFactory.hpp"
#include "MueLu_PgPFactory.hpp"
#include "MueLu_AmalgamationFactory.hpp"
#include "MueLu_TransPFactory.hpp"
#include "MueLu_GenericRFactory.hpp"
#include "MueLu_SmootherPrototype.hpp"
#include "MueLu_SmootherFactory.hpp"
#include "MueLu_TrilinosSmoother.hpp"
#include "MueLu_IfpackSmoother.hpp"
#include "MueLu_DirectSolver.hpp"
#include "MueLu_HierarchyUtils.hpp"
#include "MueLu_RAPFactory.hpp"
#include "MueLu_CoalesceDropFactory.hpp"
#include "MueLu_CoupledAggregationFactory.hpp"
#include "MueLu_UncoupledAggregationFactory.hpp"
#include "MueLu_HybridAggregationFactory.hpp"
#include "MueLu_NullspaceFactory.hpp"
#include "MueLu_ParameterListUtils.hpp"
 
#ifdef HAVE_MUELU_KOKKOS_REFACTOR
#include "MueLu_CoalesceDropFactory_kokkos.hpp"
// #include "MueLu_CoarseMapFactory_kokkos.hpp"
// #include "MueLu_CoordinatesTransferFactory_kokkos.hpp"
// #include "MueLu_NullspaceFactory_kokkos.hpp"
#include "MueLu_SaPFactory_kokkos.hpp"
#include "MueLu_TentativePFactory_kokkos.hpp"
#include "MueLu_UncoupledAggregationFactory_kokkos.hpp"
#endif
 
#if defined(HAVE_MUELU_ISORROPIA) && defined(HAVE_MPI)
#include "MueLu_IsorropiaInterface.hpp"
#include "MueLu_RepartitionHeuristicFactory.hpp"
#include "MueLu_RepartitionFactory.hpp"
#include "MueLu_RebalanceTransferFactory.hpp"
#include "MueLu_RepartitionInterface.hpp"
#include "MueLu_RebalanceAcFactory.hpp"
//#include "MueLu_RebalanceMapFactory.hpp"
#endif
 
// Note: do not add options that are only recognized by MueLu.
 
// TODO: this parameter list interpreter should force MueLu to use default ML parameters
// - Ex: smoother sweep=2 by default for ML
 
// Read a parameter value from a parameter list and store it into a variable named 'varName'
#define MUELU_READ_PARAM(paramList, paramStr, varType, defaultValue, varName) \
  varType varName = defaultValue; if (paramList.isParameter(paramStr)) varName = paramList.get<varType>(paramStr);
 
// Read a parameter value from a paraeter list and copy it into a new parameter list (with another parameter name)
#define MUELU_COPY_PARAM(paramList, paramStr, varType, defaultValue, outParamList, outParamStr) \
  if (paramList.isParameter(paramStr))                                  \
    outParamList.set(outParamStr, paramList.get<varType>(paramStr)); \
  else outParamList.set(outParamStr, static_cast<varType>(defaultValue));            \
 
namespace MueLu {
 
  template <class Scalar, class LocalOrdinal, class GlobalOrdinal, class Node>
  MLParameterListInterpreter<Scalar, LocalOrdinal, GlobalOrdinal, Node>::MLParameterListInterpreter(Teuchos::ParameterList & paramList, Teuchos::RCP<const Teuchos::Comm<int> > comm, std::vector<RCP<FactoryBase> > factoryList) : nullspace_(NULL), xcoord_(NULL), ycoord_(NULL), zcoord_(NULL),TransferFacts_(factoryList), blksize_(1) {
 
    if (paramList.isParameter("xml parameter file")){
      std::string filename = paramList.get("xml parameter file","");
      if (filename.length() != 0) {
        TEUCHOS_TEST_FOR_EXCEPTION(comm.is_null(), Exceptions::RuntimeError, "xml parameter file requires a valid comm");
        Teuchos::ParameterList paramList2 = paramList;
        Teuchos::updateParametersFromXmlFileAndBroadcast(filename, Teuchos::Ptr<Teuchos::ParameterList>(&paramList2),*comm);
        paramList2.remove("xml parameter file");
        SetParameterList(paramList2);
      }
      else
        SetParameterList(paramList);
    }
    else
      SetParameterList(paramList);
  }
 
  template <class Scalar, class LocalOrdinal, class GlobalOrdinal, class Node>
  MLParameterListInterpreter<Scalar, LocalOrdinal, GlobalOrdinal, Node>::MLParameterListInterpreter(const std::string & xmlFileName, std::vector<RCP<FactoryBase> > factoryList) : nullspace_(NULL), TransferFacts_(factoryList), blksize_(1) {
    Teuchos::RCP<Teuchos::ParameterList> paramList = Teuchos::getParametersFromXmlFile(xmlFileName);
    SetParameterList(*paramList);
  }
 
  template <class Scalar, class LocalOrdinal, class GlobalOrdinal, class Node>
  void MLParameterListInterpreter<Scalar, LocalOrdinal, GlobalOrdinal, Node>::SetParameterList(const Teuchos::ParameterList & paramList_in) {
    Teuchos::ParameterList paramList = paramList_in;
 
    //
    // Read top-level of the parameter list
    //
 
    // hard-coded default values == ML defaults according to the manual
    MUELU_READ_PARAM(paramList, "ML output",                                int,                   0,       verbosityLevel);
    MUELU_READ_PARAM(paramList, "max levels",                               int,                  10,       maxLevels);
    MUELU_READ_PARAM(paramList, "PDE equations",                            int,                   1,       nDofsPerNode);
 
    MUELU_READ_PARAM(paramList, "coarse: max size",                         int,                 128,       maxCoarseSize);
 
    MUELU_READ_PARAM(paramList, "aggregation: type",                std::string,         "Uncoupled",       agg_type);
    //MUELU_READ_PARAM(paramList, "aggregation: threshold",                double,                 0.0,       agg_threshold);
    MUELU_READ_PARAM(paramList, "aggregation: damping factor",           double, (double)4/(double)3,       agg_damping);
    //MUELU_READ_PARAM(paramList, "aggregation: smoothing sweeps",            int,                   1,       agg_smoothingsweeps);
    MUELU_READ_PARAM(paramList, "aggregation: nodes per aggregate",         int,                   1,       minPerAgg);
    MUELU_READ_PARAM(paramList, "aggregation: keep Dirichlet bcs",         bool,               false,       bKeepDirichletBcs); // This is a MueLu specific extension that does not exist in ML
    MUELU_READ_PARAM(paramList, "aggregation: max neighbours already aggregated", int,             0,       maxNbrAlreadySelected); // This is a MueLu specific extension that does not exist in M
    MUELU_READ_PARAM(paramList, "aggregation: aux: enable",                bool,               false,       agg_use_aux);
    MUELU_READ_PARAM(paramList, "aggregation: aux: threshold",           double,               false,       agg_aux_thresh);
 
    MUELU_READ_PARAM(paramList, "null space: type",                 std::string,   "default vectors",       nullspaceType);
    MUELU_READ_PARAM(paramList, "null space: dimension",                    int,                  -1,       nullspaceDim); // TODO: ML default not in documentation
    MUELU_READ_PARAM(paramList, "null space: vectors",                   double*,               NULL,       nullspaceVec); // TODO: ML default not in documentation
 
    MUELU_READ_PARAM(paramList, "energy minimization: enable",             bool,               false,       bEnergyMinimization);
 
    MUELU_READ_PARAM(paramList, "RAP: fix diagonal",                       bool,               false,       bFixDiagonal); // This is a MueLu specific extension that does not exist in ML
 
    MUELU_READ_PARAM(paramList, "x-coordinates",                        double*,                NULL,       xcoord);
    MUELU_READ_PARAM(paramList, "y-coordinates",                        double*,                NULL,       ycoord);
    MUELU_READ_PARAM(paramList, "z-coordinates",                        double*,                NULL,       zcoord);
 
 
    //
    // Move smoothers/aggregation/coarse parameters to sublists
    //
 
    // ML allows to have level-specific smoothers/aggregation/coarse parameters at the top level of the list or/and defined in sublists:
    // See also: ML Guide section 6.4.1, MueLu::CreateSublists, ML_CreateSublists
    ParameterList paramListWithSubList;
    MueLu::CreateSublists(paramList, paramListWithSubList);
    paramList = paramListWithSubList; // swap
 
    // pull out "use kokkos refactor"
    bool setKokkosRefactor = false;
#if ( defined(HAVE_MUELU_KOKKOS_REFACTOR) && defined(HAVE_MUELU_KOKKOS_REFACTOR_USE_BY_DEFAULT) )
    bool useKokkosRefactor = true;
#else
    bool useKokkosRefactor = false;
#endif
    if (paramList.isType<bool>("use kokkos refactor")) {
      useKokkosRefactor = paramList.get<bool>("use kokkos refactor");
      setKokkosRefactor = true;
      paramList.remove("use kokkos refactor");
    }
 
    //
    // Validate parameter list
    //
 
    {
      bool validate = paramList.get("ML validate parameter list", true); /* true = default in ML */
      if (validate) {
 
#if defined(HAVE_MUELU_ML) && defined(HAVE_MUELU_EPETRA)
        // Validate parameter list using ML validator
        int depth = paramList.get("ML validate depth", 5); /* 5 = default in ML */
        TEUCHOS_TEST_FOR_EXCEPTION(! ML_Epetra::ValidateMLPParameters(paramList, depth), Exceptions::RuntimeError,
                                   "ERROR: ML's Teuchos::ParameterList contains incorrect parameter!");
#else
        // If no validator available: issue a warning and set parameter value to false in the output list
        this->GetOStream(Warnings0) << "Warning: MueLu_ENABLE_ML=OFF. The parameter list cannot be validated." << std::endl;
        paramList.set("ML validate parameter list", false);
 
#endif // HAVE_MUELU_ML
      } // if(validate)
    } // scope
 
 
    // Matrix option
    blksize_ = nDofsPerNode;
 
    // Translate verbosity parameter
 
    // Translate verbosity parameter
    MsgType eVerbLevel = None;
    if (verbosityLevel ==  0) eVerbLevel = None;
    if (verbosityLevel >=  1) eVerbLevel = Low;
    if (verbosityLevel >=  5) eVerbLevel = Medium;
    if (verbosityLevel >= 10) eVerbLevel = High;
    if (verbosityLevel >= 11) eVerbLevel = Extreme;
    if (verbosityLevel >= 42) eVerbLevel = Test;
    this->verbosity_ = eVerbLevel;
 
 
    TEUCHOS_TEST_FOR_EXCEPTION(agg_type != "Uncoupled" && agg_type != "Coupled", Exceptions::RuntimeError,
        "MueLu::MLParameterListInterpreter::SetParameterList(): parameter \"aggregation: type\": only 'Uncoupled' or 'Coupled' aggregation is supported.");
 
    // Create MueLu factories
    RCP<Factory> dropFact;
#ifdef HAVE_MUELU_KOKKOS_REFACTOR
    if(useKokkosRefactor)
      dropFact = rcp( new CoalesceDropFactory_kokkos() );
    else
#endif
      dropFact = rcp( new CoalesceDropFactory() );
 
    if (agg_use_aux) {
      dropFact->SetParameter("aggregation: drop scheme",Teuchos::ParameterEntry(std::string("distance laplacian")));
      dropFact->SetParameter("aggregation: drop tol",Teuchos::ParameterEntry(agg_aux_thresh));
    }
 
    RCP<Factory> AggFact = Teuchos::null;
    if (agg_type == "Uncoupled") {
      // Uncoupled aggregation
      RCP<Factory> MyUncoupledAggFact;
#ifdef HAVE_MUELU_KOKKOS_REFACTOR
      if(useKokkosRefactor) {
        MyUncoupledAggFact = rcp( new UncoupledAggregationFactory_kokkos() );
      }
      else
#endif
        MyUncoupledAggFact = rcp( new UncoupledAggregationFactory() );
 
      MyUncoupledAggFact->SetFactory("Graph", dropFact);
      MyUncoupledAggFact->SetFactory("DofsPerNode", dropFact);
      MyUncoupledAggFact->SetParameter("aggregation: preserve Dirichlet points", Teuchos::ParameterEntry(bKeepDirichletBcs));
      MyUncoupledAggFact->SetParameter("aggregation: ordering",                  Teuchos::ParameterEntry(std::string("natural")));
      MyUncoupledAggFact->SetParameter("aggregation: max selected neighbors",    Teuchos::ParameterEntry(maxNbrAlreadySelected));
      MyUncoupledAggFact->SetParameter("aggregation: min agg size",              Teuchos::ParameterEntry(minPerAgg));
 
      AggFact = MyUncoupledAggFact;
    } else {
      // Coupled Aggregation (default)
#ifdef HAVE_MUELU_KOKKOS_REFACTOR
      if(useKokkosRefactor) {
        AggFact = rcp( new UncoupledAggregationFactory_kokkos() );
      } else {
        RCP<CoupledAggregationFactory> CoupledAggFact2 = rcp( new CoupledAggregationFactory() );
        CoupledAggFact2->SetMinNodesPerAggregate(minPerAgg); //TODO should increase if run anything other than 1D
        CoupledAggFact2->SetMaxNeighAlreadySelected(maxNbrAlreadySelected);
        CoupledAggFact2->SetOrdering("natural");
        CoupledAggFact2->SetPhase3AggCreation(0.5);
        CoupledAggFact2->SetFactory("Graph", dropFact);
        CoupledAggFact2->SetFactory("DofsPerNode", dropFact);
        AggFact = CoupledAggFact2;
      }
#else
      RCP<CoupledAggregationFactory> CoupledAggFact2 = rcp( new CoupledAggregationFactory() );
      CoupledAggFact2 = rcp( new CoupledAggregationFactory() );
      CoupledAggFact2->SetMinNodesPerAggregate(minPerAgg); //TODO should increase if run anything other than 1D
      CoupledAggFact2->SetMaxNeighAlreadySelected(maxNbrAlreadySelected);
      CoupledAggFact2->SetOrdering("natural");
      CoupledAggFact2->SetPhase3AggCreation(0.5);
      CoupledAggFact2->SetFactory("Graph", dropFact);
      CoupledAggFact2->SetFactory("DofsPerNode", dropFact);
      AggFact = CoupledAggFact2;
#endif
    }
    if (verbosityLevel > 3) {
      std::ostringstream oss;
      oss << "========================= Aggregate option summary  =========================" << std::endl;
      oss << "min Nodes per aggregate :               " << minPerAgg << std::endl;
      oss << "min # of root nbrs already aggregated : " << maxNbrAlreadySelected << std::endl;
      oss << "aggregate ordering :                    natural" << std::endl;
      oss << "=============================================================================" << std::endl;
      this->GetOStream(Runtime1) << oss.str();
    }
 
    RCP<Factory> PFact;
    RCP<Factory> RFact;
    RCP<Factory> PtentFact;
#ifdef HAVE_MUELU_KOKKOS_REFACTOR
    if(useKokkosRefactor)
      PtentFact = rcp( new TentativePFactory_kokkos() );
    else
#endif
      PtentFact = rcp( new TentativePFactory() );
    if (agg_damping == 0.0 && bEnergyMinimization == false) {
      // tentative prolongation operator (PA-AMG)
      PFact = PtentFact;
      RFact = rcp( new TransPFactory() );
    } else if (agg_damping != 0.0 && bEnergyMinimization == false) {
      // smoothed aggregation (SA-AMG)
      RCP<Factory> SaPFact;
#ifdef HAVE_MUELU_KOKKOS_REFACTOR
    if(useKokkosRefactor)
      SaPFact = rcp( new SaPFactory_kokkos() );
    else
#endif
      SaPFact = rcp( new SaPFactory() );
      SaPFact->SetParameter("sa: damping factor", ParameterEntry(agg_damping));
      PFact  = SaPFact;
      RFact  = rcp( new TransPFactory() );
    } else if (bEnergyMinimization == true) {
      // Petrov Galerkin PG-AMG smoothed aggregation (energy minimization in ML)
      PFact  = rcp( new PgPFactory() );
      RFact  = rcp( new GenericRFactory() );
    }
 
    RCP<RAPFactory> AcFact = rcp( new RAPFactory() );
    AcFact->SetParameter("RepairMainDiagonal", Teuchos::ParameterEntry(bFixDiagonal));
    for (size_t i = 0; i<TransferFacts_.size(); i++) {
      AcFact->AddTransferFactory(TransferFacts_[i]);
    }
 
    //
    // introduce rebalancing
    //
#if defined(HAVE_MUELU_ISORROPIA) && defined(HAVE_MPI)
    Teuchos::RCP<Factory>            RebalancedPFact = Teuchos::null;
    Teuchos::RCP<Factory>            RebalancedRFact = Teuchos::null;
    Teuchos::RCP<Factory>            RepartitionFact = Teuchos::null;
    Teuchos::RCP<RebalanceAcFactory> RebalancedAFact = Teuchos::null;
 
    MUELU_READ_PARAM(paramList, "repartition: enable",                      int,                   0,       bDoRepartition);
    if (bDoRepartition == 1) {
      // The Factory Manager will be configured to return the rebalanced versions of P, R, A by default.
      // Everytime we want to use the non-rebalanced versions, we need to explicitly define the generating factory.
      RFact->SetFactory("P", PFact);
      //
      AcFact->SetFactory("P", PFact);
      AcFact->SetFactory("R", RFact);
 
      // define rebalancing factory for coarse matrix
      Teuchos::RCP<MueLu::AmalgamationFactory<SC, LO, GO, NO> > rebAmalgFact = Teuchos::rcp(new MueLu::AmalgamationFactory<SC, LO, GO, NO>());
      rebAmalgFact->SetFactory("A", AcFact);
 
      MUELU_READ_PARAM(paramList, "repartition: max min ratio",            double,                 1.3,       maxminratio);
      MUELU_READ_PARAM(paramList, "repartition: min per proc",                int,                 512,       minperproc);
 
      // Repartitioning heuristic
      RCP<RepartitionHeuristicFactory> RepartitionHeuristicFact = Teuchos::rcp(new RepartitionHeuristicFactory());
      {
        Teuchos::ParameterList paramListRepFact;
        paramListRepFact.set("repartition: min rows per proc", minperproc);
        paramListRepFact.set("repartition: max imbalance", maxminratio);
        RepartitionHeuristicFact->SetParameterList(paramListRepFact);
      }
      RepartitionHeuristicFact->SetFactory("A", AcFact);
 
      // create "Partition"
      Teuchos::RCP<MueLu::IsorropiaInterface<LO, GO, NO> > isoInterface = Teuchos::rcp(new MueLu::IsorropiaInterface<LO, GO, NO>());
      isoInterface->SetFactory("A", AcFact);
      isoInterface->SetFactory("number of partitions", RepartitionHeuristicFact);
      isoInterface->SetFactory("UnAmalgamationInfo", rebAmalgFact);
 
      // create "Partition" by unamalgamtion
      Teuchos::RCP<MueLu::RepartitionInterface<LO, GO, NO> > repInterface = Teuchos::rcp(new MueLu::RepartitionInterface<LO, GO, NO>());
      repInterface->SetFactory("A", AcFact);
      repInterface->SetFactory("number of partitions", RepartitionHeuristicFact);
      repInterface->SetFactory("AmalgamatedPartition", isoInterface);
      //repInterface->SetFactory("UnAmalgamationInfo", rebAmalgFact); // not necessary?
 
      // Repartitioning (creates "Importer" from "Partition")
      RepartitionFact = Teuchos::rcp(new RepartitionFactory());
      RepartitionFact->SetFactory("A", AcFact);
      RepartitionFact->SetFactory("number of partitions", RepartitionHeuristicFact);
      RepartitionFact->SetFactory("Partition", repInterface);
 
      // Reordering of the transfer operators
      RebalancedPFact = Teuchos::rcp(new RebalanceTransferFactory());
      RebalancedPFact->SetParameter("type", Teuchos::ParameterEntry(std::string("Interpolation")));
      RebalancedPFact->SetFactory("P", PFact);
      RebalancedPFact->SetFactory("Nullspace", PtentFact);
      RebalancedPFact->SetFactory("Importer",    RepartitionFact);
 
      RebalancedRFact = Teuchos::rcp(new RebalanceTransferFactory());
      RebalancedRFact->SetParameter("type", Teuchos::ParameterEntry(std::string("Restriction")));
      RebalancedRFact->SetFactory("R", RFact);
      RebalancedRFact->SetFactory("Importer",    RepartitionFact);
 
      // Compute Ac from rebalanced P and R
      RebalancedAFact = Teuchos::rcp(new RebalanceAcFactory());
      RebalancedAFact->SetFactory("A", AcFact);
    }
#else // #ifdef HAVE_MUELU_ISORROPIA
    // Get rid of [-Wunused] warnings
    //(void)
    //
    // ^^^ FIXME (mfh 17 Nov 2013) That definitely doesn't compile.
#endif
 
    //
    // Nullspace factory
    //
 
    // Set fine level nullspace
    // extract pre-computed nullspace from ML parameter list
    // store it in nullspace_ and nullspaceDim_
    if (nullspaceType != "default vectors") {
      TEUCHOS_TEST_FOR_EXCEPTION(nullspaceType != "pre-computed", Exceptions::RuntimeError, "MueLu::MLParameterListInterpreter: no valid nullspace (no pre-computed null space). error.");
      TEUCHOS_TEST_FOR_EXCEPTION(nullspaceDim  == -1,             Exceptions::RuntimeError, "MueLu::MLParameterListInterpreter: no valid nullspace (nullspace dim == -1). error.");
      TEUCHOS_TEST_FOR_EXCEPTION(nullspaceVec  == NULL,           Exceptions::RuntimeError, "MueLu::MLParameterListInterpreter: no valid nullspace (nullspace == NULL). You have to provide a valid fine-level nullspace in \'null space: vectors\'");
 
      nullspaceDim_ = nullspaceDim;
      nullspace_    = nullspaceVec;
    }
 
    Teuchos::RCP<NullspaceFactory> nspFact = Teuchos::rcp(new NullspaceFactory("Nullspace"));
    nspFact->SetFactory("Nullspace", PtentFact);
 
 
    // Stash coordinates
    xcoord_ = xcoord;
    ycoord_ = ycoord;
    zcoord_ = zcoord;
 
 
 
    //
    // Hierarchy + FactoryManager
    //
 
    // Hierarchy options
    this->numDesiredLevel_ = maxLevels;
    this->maxCoarseSize_   = maxCoarseSize;
 
    //
    // Coarse Smoother
    //
    ParameterList& coarseList = paramList.sublist("coarse: list");
    // check whether coarse solver is set properly. If not, set default coarse solver.
    if (!coarseList.isParameter("smoother: type"))
      coarseList.set("smoother: type", "Amesos-KLU"); // set default coarse solver according to ML 5.0 guide
    RCP<SmootherFactory> coarseFact = GetSmootherFactory(coarseList, Teuchos::null);
 
    // Smoothers Top Level Parameters
 
    RCP<ParameterList> topLevelSmootherParam = ExtractSetOfParameters(paramList, "smoother");
 
    //
 
    // Prepare factory managers
    // TODO: smootherFact can be reuse accross level if same parameters/no specific parameterList
 
    for (int levelID=0; levelID < maxLevels; levelID++) {
 
      //
      // Level FactoryManager
      //
 
      RCP<FactoryManager> manager = rcp(new FactoryManager());
      if (setKokkosRefactor)
        manager->SetKokkosRefactor(useKokkosRefactor);
 
      //
      // Smoothers
      //
 
      {
        // Merge level-specific parameters with global parameters. level-specific parameters takes precedence.
        // TODO: unit-test this part alone
 
        ParameterList levelSmootherParam = GetMLSubList(paramList, "smoother", levelID); // copy
        MergeParameterList(*topLevelSmootherParam, levelSmootherParam, false); /* false = do no overwrite levelSmootherParam parameters by topLevelSmootherParam parameters */
        // std::cout << std::endl << "Merged List for level  " << levelID << std::endl;
        // std::cout << levelSmootherParam << std::endl;
 
        RCP<SmootherFactory> smootherFact = GetSmootherFactory(levelSmootherParam, Teuchos::null); // TODO: missing AFact input arg.
 
        manager->SetFactory("Smoother", smootherFact);
      }
 
      //
      // Misc
      //
 
      manager->SetFactory("CoarseSolver", coarseFact); // TODO: should not be done in the loop
      manager->SetFactory("Graph", dropFact);
      manager->SetFactory("Aggregates", AggFact);
      manager->SetFactory("DofsPerNode", dropFact);
      manager->SetFactory("Ptent", PtentFact);
 
#if defined(HAVE_MUELU_ISORROPIA) && defined(HAVE_MPI)
    if (bDoRepartition == 1) {
      manager->SetFactory("A", RebalancedAFact);
      manager->SetFactory("P", RebalancedPFact);
      manager->SetFactory("R", RebalancedRFact);
      manager->SetFactory("Nullspace",   RebalancedPFact);
      manager->SetFactory("Importer",    RepartitionFact);
    } else {
#endif // #ifdef HAVE_MUELU_ISORROPIA
      manager->SetFactory("Nullspace", nspFact); // use same nullspace factory throughout all multigrid levels
      manager->SetFactory("A", AcFact);          // same RAP factory for all levels
      manager->SetFactory("P", PFact);           // same prolongator and restrictor factories for all levels
      manager->SetFactory("R", RFact);           // same prolongator and restrictor factories for all levels
#if defined(HAVE_MUELU_ISORROPIA) && defined(HAVE_MPI)
    }
#endif
 
      this->AddFactoryManager(levelID, 1, manager);
    } // for (level loop)
 
  }
 
  template <class Scalar, class LocalOrdinal, class GlobalOrdinal, class Node>
  void MLParameterListInterpreter<Scalar, LocalOrdinal, GlobalOrdinal, Node>::SetupHierarchy(Hierarchy & H) const {
    // if nullspace_ has already been extracted from ML parameter list
    // make nullspace available for MueLu
    if (nullspace_ != NULL) {
      RCP<Level> fineLevel = H.GetLevel(0);
      RCP<Operator> Op = fineLevel->Get<RCP<Operator> >("A");
      RCP<Matrix>   A  = rcp_dynamic_cast<Matrix>(Op);
      if (!A.is_null()) {
        const RCP<const Map> rowMap = fineLevel->Get< RCP<Matrix> >("A")->getRowMap();
        RCP<MultiVector> nullspace = MultiVectorFactory::Build(rowMap, nullspaceDim_, true);
 
        for ( size_t i=0; i < Teuchos::as<size_t>(nullspaceDim_); i++) {
          Teuchos::ArrayRCP<Scalar> nullspacei = nullspace->getDataNonConst(i);
          const size_t              myLength   = nullspace->getLocalLength();
 
          for (size_t j = 0; j < myLength; j++) {
            nullspacei[j] = nullspace_[i*myLength + j];
          }
        }
 
        fineLevel->Set("Nullspace", nullspace);
      }
    }
 
    // Do the same for coordinates
    size_t num_coords = 0;
    double * coordPTR[3];
    if (xcoord_) {
      coordPTR[0] = xcoord_;
      num_coords++;
      if (ycoord_) {
        coordPTR[1] = ycoord_;
        num_coords++;
        if (zcoord_) {
          coordPTR[2] = zcoord_;
          num_coords++;
        }
      }
    }
    if (num_coords){
      Teuchos::RCP<Level> fineLevel = H.GetLevel(0);
      Teuchos::RCP<Operator> Op = fineLevel->Get<RCP<Operator> >("A");
      Teuchos::RCP<Matrix>   A  = rcp_dynamic_cast<Matrix>(Op);
      if (!A.is_null()) {
        const Teuchos::RCP<const Map> rowMap = fineLevel->Get< RCP<Matrix> >("A")->getRowMap();
        Teuchos::RCP<MultiVector> coordinates = MultiVectorFactory::Build(rowMap, num_coords, true);
 
        for ( size_t i=0; i < num_coords; i++) {
          Teuchos::ArrayRCP<Scalar> coordsi  = coordinates->getDataNonConst(i);
          const size_t              myLength = coordinates->getLocalLength();
          for (size_t j = 0; j < myLength; j++) {
            coordsi[j] = coordPTR[0][j];
          }
        }
        fineLevel->Set("Coordinates",coordinates);
      }
    }
 
    HierarchyManager::SetupHierarchy(H);
  }
 
  // TODO: code factorization with MueLu_ParameterListInterpreter.
  template <class Scalar, class LocalOrdinal, class GlobalOrdinal, class Node>
  RCP<MueLu::SmootherFactory<Scalar, LocalOrdinal, GlobalOrdinal, Node> >
  MLParameterListInterpreter<Scalar, LocalOrdinal, GlobalOrdinal, Node>::
  GetSmootherFactory (const Teuchos::ParameterList & paramList,
                      const RCP<FactoryBase> & AFact)
  {
    typedef Teuchos::ScalarTraits<Scalar> STS;
    SC one = STS::one();
 
    std::string type = "symmetric Gauss-Seidel"; // default
 
    //
    // Get 'type'
    //
 
//     //TODO: fix defaults!!
 
//     // Default coarse grid smoother
//     std::string type;
//     if ("smoother" == "coarse") {
// #if (defined(HAVE_MUELU_EPETRA) && defined( HAVE_MUELU_AMESOS)) || (defined(HAVE_MUELU_TPETRA) && defined(HAVE_MUELU_AMESOS2)) // FIXME: test is wrong (ex: compiled with Epetra&&Tpetra&&Amesos2 but without Amesos => error running Epetra problem)
//       type = ""; // use default defined by AmesosSmoother or Amesos2Smoother
// #else
//       type = "symmetric Gauss-Seidel"; // use a sym Gauss-Seidel (with no damping) as fallback "coarse solver" (TODO: needs Ifpack(2))
// #endif
//     } else {
//       // TODO: default smoother?
//       type = "";
//     }
 
 
    if (paramList.isParameter("smoother: type")) type = paramList.get<std::string>("smoother: type");
    TEUCHOS_TEST_FOR_EXCEPTION(type.empty(), Exceptions::RuntimeError, "MueLu::MLParameterListInterpreter: no \"smoother: type\" in the smoother parameter list" << std::endl << paramList);
 
    //
    // Create the smoother prototype
    //
 
    RCP<SmootherPrototype> smooProto;
    std::string ifpackType;
    Teuchos::ParameterList smootherParamList;
 
    if (type == "Jacobi" || type == "Gauss-Seidel" || type == "symmetric Gauss-Seidel") {
      if (type == "symmetric Gauss-Seidel") type = "Symmetric Gauss-Seidel"; // FIXME
 
      ifpackType = "RELAXATION";
      smootherParamList.set("relaxation: type", type);
 
      MUELU_COPY_PARAM(paramList, "smoother: sweeps",            int,   2, smootherParamList, "relaxation: sweeps");
      MUELU_COPY_PARAM(paramList, "smoother: damping factor", Scalar, one, smootherParamList, "relaxation: damping factor");
 
      smooProto = rcp( new TrilinosSmoother(ifpackType, smootherParamList, 0) );
      smooProto->SetFactory("A", AFact);
 
    } else if (type == "Chebyshev" || type == "MLS") {
 
      ifpackType = "CHEBYSHEV";
 
      MUELU_COPY_PARAM(paramList, "smoother: sweeps",          int, 2,     smootherParamList, "chebyshev: degree");
      if (paramList.isParameter("smoother: MLS alpha")) {
        MUELU_COPY_PARAM(paramList, "smoother: MLS alpha", double, 20, smootherParamList, "chebyshev: ratio eigenvalue");
      } else {
        MUELU_COPY_PARAM(paramList, "smoother: Chebyshev alpha", double, 20, smootherParamList, "chebyshev: ratio eigenvalue");
      }
 
 
      smooProto = rcp( new TrilinosSmoother(ifpackType, smootherParamList, 0) );
      smooProto->SetFactory("A", AFact);
 
    } else if (type == "IFPACK") { // TODO: this option is not described in the ML Guide v5.0
 
#if defined(HAVE_MUELU_EPETRA) && defined(HAVE_MUELU_IFPACK)
      ifpackType = paramList.get<std::string>("smoother: ifpack type");
 
      if (ifpackType == "ILU") {
        // TODO fix this (type mismatch double vs. int)
        //MUELU_COPY_PARAM(paramList, "smoother: ifpack level-of-fill", double /*int*/, 0.0 /*2*/,  smootherParamList, "fact: level-of-fill");
        if (paramList.isParameter("smoother: ifpack level-of-fill"))
          smootherParamList.set("fact: level-of-fill", Teuchos::as<int>(paramList.get<double>("smoother: ifpack level-of-fill")));
        else smootherParamList.set("fact: level-of-fill", as<int>(0));
 
        MUELU_COPY_PARAM(paramList, "smoother: ifpack overlap",       int, 2,  smootherParamList, "partitioner: overlap");
 
        // TODO change to TrilinosSmoother as soon as Ifpack2 supports all preconditioners from Ifpack
        smooProto =
          MueLu::GetIfpackSmoother<Scalar, LocalOrdinal, GlobalOrdinal, Node> (ifpackType,
                                                                               smootherParamList,
                                                                               paramList.get<int> ("smoother: ifpack overlap"));
        smooProto->SetFactory("A", AFact);
      } else {
        TEUCHOS_TEST_FOR_EXCEPTION(true, Exceptions::RuntimeError, "MueLu::MLParameterListInterpreter: unknown ML smoother type " + type + " (IFPACK) not supported by MueLu. Only ILU is supported.");
      }
#else
      TEUCHOS_TEST_FOR_EXCEPTION(true, Exceptions::RuntimeError, "MueLu::MLParameterListInterpreter: MueLu compiled without Ifpack support");
#endif
 
    } else if (type.length() > strlen("Amesos") && type.substr(0, strlen("Amesos")) == "Amesos") {  /* catch Amesos-* */
      std::string solverType = type.substr(strlen("Amesos")+1);  /* ("Amesos-KLU" -> "KLU") */
 
      // Validator: following upper/lower case is what is allowed by ML
      bool valid = false;
      const int  validatorSize = 5;
      std::string validator[validatorSize] = {"Superlu", "Superludist", "KLU", "UMFPACK"}; /* TODO: should "" be allowed? */
      for (int i=0; i < validatorSize; i++) { if (validator[i] == solverType) valid = true; }
      TEUCHOS_TEST_FOR_EXCEPTION(!valid, Exceptions::RuntimeError, "MueLu::MLParameterListInterpreter: unknown smoother type. '" << type << "' not supported.");
 
      // FIXME: MueLu should accept any Upper/Lower case. Not the case for the moment
      std::transform(solverType.begin()+1, solverType.end(), solverType.begin()+1, ::tolower);
 
      smooProto = Teuchos::rcp( new DirectSolver(solverType, Teuchos::ParameterList()) );
      smooProto->SetFactory("A", AFact);
 
    } else {
 
      TEUCHOS_TEST_FOR_EXCEPTION(true, Exceptions::RuntimeError, "MueLu::MLParameterListInterpreter: unknown smoother type. '" << type << "' not supported by MueLu.");
 
    }
    TEUCHOS_TEST_FOR_EXCEPTION(smooProto == Teuchos::null, Exceptions::RuntimeError, "MueLu::MLParameterListInterpreter: no smoother prototype. fatal error.");
 
    //
    // Create the smoother factory
    //
 
    RCP<SmootherFactory> SmooFact = rcp( new SmootherFactory() );
 
    // Set parameters of the smoother factory
    MUELU_READ_PARAM(paramList, "smoother: pre or post", std::string, "both", preOrPost);
    if (preOrPost == "both") {
      SmooFact->SetSmootherPrototypes(smooProto, smooProto);
    } else if (preOrPost == "pre") {
      SmooFact->SetSmootherPrototypes(smooProto, Teuchos::null);
    } else if (preOrPost == "post") {
      SmooFact->SetSmootherPrototypes(Teuchos::null, smooProto);
    }
 
    return SmooFact;
  }
 
  template <class Scalar, class LocalOrdinal, class GlobalOrdinal, class Node>
  void MLParameterListInterpreter<Scalar, LocalOrdinal, GlobalOrdinal, Node>::AddTransferFactory(const RCP<FactoryBase>& factory) {
    // check if it's a TwoLevelFactoryBase based transfer factory
    TEUCHOS_TEST_FOR_EXCEPTION(Teuchos::rcp_dynamic_cast<TwoLevelFactoryBase>(factory) == Teuchos::null, Exceptions::BadCast, "Transfer factory is not derived from TwoLevelFactoryBase. Since transfer factories will be handled by the RAPFactory they have to be derived from TwoLevelFactoryBase!");
    TransferFacts_.push_back(factory);
  }
 
  template <class Scalar, class LocalOrdinal, class GlobalOrdinal, class Node>
  size_t MLParameterListInterpreter<Scalar, LocalOrdinal, GlobalOrdinal, Node>::NumTransferFactories() const {
    return TransferFacts_.size();
  }
 
  template <class Scalar, class LocalOrdinal, class GlobalOrdinal, class Node>
  void MLParameterListInterpreter<Scalar, LocalOrdinal, GlobalOrdinal, Node>::SetupOperator(Operator & Op) const {
    try {
      Matrix& A = dynamic_cast<Matrix&>(Op);
      if (A.GetFixedBlockSize() != blksize_)
        this->GetOStream(Warnings0) << "Setting matrix block size to " << blksize_ << " (value of the parameter in the list) "
            << "instead of " << A.GetFixedBlockSize() << " (provided matrix)." << std::endl;
 
      A.SetFixedBlockSize(blksize_);
 
    } catch (std::bad_cast& e) {
      this->GetOStream(Warnings0) << "Skipping setting block size as the operator is not a matrix" << std::endl;
    }
  }
 
} // namespace MueLu
 
#define MUELU_MLPARAMETERLISTINTERPRETER_SHORT
#endif /* MUELU_MLPARAMETERLISTINTERPRETER_DEF_HPP */
 
//TODO: see if it can be factorized with ML interpreter (ex: generation of Ifpack param list)