MueLu_TrilinosSmoother_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_TRILINOSSMOOTHER_DEF_HPP
#define MUELU_TRILINOSSMOOTHER_DEF_HPP

#include <Xpetra_Map.hpp>
#include <Xpetra_Matrix.hpp>

#include "MueLu_TrilinosSmoother_decl.hpp"

#include "MueLu_Level.hpp"
#include "MueLu_IfpackSmoother.hpp"
#include "MueLu_Ifpack2Smoother.hpp"
#include "MueLu_BelosSmoother.hpp"
#include "MueLu_StratimikosSmoother.hpp"
#include "MueLu_Exceptions.hpp"

namespace MueLu {

template <class Scalar, class LocalOrdinal, class GlobalOrdinal, class Node>
TrilinosSmoother<Scalar, LocalOrdinal, GlobalOrdinal, Node>::TrilinosSmoother(const std::string& type, const Teuchos::ParameterList& paramListIn, const LO& overlap)
  : type_(type)
  , overlap_(overlap) {
  // The original idea behind all smoothers was to use prototype pattern. However, it does not fully work of the dependencies
  // calculation. Particularly, we need to propagate DeclareInput to proper prototypes. Therefore, both TrilinosSmoother and
  // DirectSolver do not follow the pattern exactly.
  // The difference is that in order to propagate the calculation of dependencies, we need to call a DeclareInput on a
  // constructed object (or objects, as we have two different code branches for Epetra and Tpetra). The only place where we
  // could construct these objects is the constructor. Thus, we need to store RCPs, and both TrilinosSmoother and DirectSolver
  // obtain a state: they contain RCP to smoother prototypes.
  sEpetra_      = Teuchos::null;
  sTpetra_      = Teuchos::null;
  sBelos_       = Teuchos::null;
  sStratimikos_ = Teuchos::null;

  TEUCHOS_TEST_FOR_EXCEPTION(overlap_ < 0, Exceptions::RuntimeError, "Overlap parameter is negative (" << overlap << ")");

  // paramList contains only parameters which are understood by Ifpack/Ifpack2
  ParameterList paramList = paramListIn;

  // We want TrilinosSmoother to be able to work with both Epetra and Tpetra objects, therefore we try to construct both
  // Ifpack and Ifpack2 smoother prototypes. The construction really depends on configuration options.
  triedEpetra_ = triedTpetra_ = triedBelos_ = triedStratimikos_ = false;
#if defined(HAVE_MUELU_IFPACK2)
  try {
    sTpetra_ = rcp(new Ifpack2Smoother(type_, paramList, overlap_));
    if (sTpetra_.is_null())
      errorTpetra_ = "Unable to construct Ifpack2 smoother";
    else if (!sTpetra_->constructionSuccessful()) {
      errorTpetra_ = sTpetra_->constructionErrorMsg();
      sTpetra_     = Teuchos::null;
    }
  } catch (Exceptions::RuntimeError& e) {
    errorTpetra_ = e.what();
  } catch (Exceptions::BadCast& e) {
    errorTpetra_ = e.what();
  } catch (Teuchos::Exceptions::InvalidParameterName& e) {
    errorTpetra_ = e.what();
  }
  triedTpetra_ = true;
#endif
#if defined(HAVE_MUELU_EPETRA) && defined(HAVE_MUELU_IFPACK)
  try {
    // GetIfpackSmoother masks the template argument matching, and simply throws if template arguments are incompatible with Epetra
    sEpetra_ = GetIfpackSmoother<SC, LO, GO, NO>(TrilinosSmoother::Ifpack2ToIfpack1Type(type_), TrilinosSmoother::Ifpack2ToIfpack1Param(paramList), overlap_);
    if (sEpetra_.is_null())
      errorEpetra_ = "Unable to construct Ifpack smoother";
    else if (!sEpetra_->constructionSuccessful()) {
      errorEpetra_ = sEpetra_->constructionErrorMsg();
      sEpetra_     = Teuchos::null;
    }
  } catch (Exceptions::RuntimeError& e) {
    // IfpackSmoother throws if Scalar != double, LocalOrdinal != int, GlobalOrdinal != int
    errorEpetra_ = e.what();
  }
  triedEpetra_ = true;
#endif
#if defined(HAVE_MUELU_BELOS)
  try {
    sBelos_ = rcp(new BelosSmoother(type_, paramList));
    if (sBelos_.is_null())
      errorBelos_ = "Unable to construct Belos smoother";
    else if (!sBelos_->constructionSuccessful()) {
      errorBelos_ = sBelos_->constructionErrorMsg();
      sBelos_     = Teuchos::null;
    }
  } catch (Exceptions::RuntimeError& e) {
    errorBelos_ = e.what();
  } catch (Exceptions::BadCast& e) {
    errorBelos_ = e.what();
  }
  triedBelos_ = true;
#endif
#if defined(HAVE_MUELU_STRATIMIKOS) && defined(HAVE_MUELU_THYRA)
  try {
    sStratimikos_ = rcp(new StratimikosSmoother(type_, paramList));
    if (sStratimikos_.is_null())
      errorStratimikos_ = "Unable to construct Stratimikos smoother";
    else if (!sStratimikos_->constructionSuccessful()) {
      errorStratimikos_ = sStratimikos_->constructionErrorMsg();
      sStratimikos_     = Teuchos::null;
    }
  } catch (Exceptions::RuntimeError& e) {
    errorStratimikos_ = e.what();
  }
  triedStratimikos_ = true;
#endif

  // Check if we were able to construct at least one smoother. In many cases that's all we need, for instance if a user
  // simply wants to use Tpetra only stack, never enables Ifpack, and always runs Tpetra objects.
  TEUCHOS_TEST_FOR_EXCEPTION(!triedEpetra_ && !triedTpetra_ && !triedBelos_ && !triedStratimikos_, Exceptions::RuntimeError,
                             "Unable to construct any smoother."
                             "Please enable (TPETRA and IFPACK2) or (EPETRA and IFPACK) or (BELOS) or (STRATIMIKOS)");

  TEUCHOS_TEST_FOR_EXCEPTION(sEpetra_.is_null() && sTpetra_.is_null() && sBelos_.is_null() && sStratimikos_.is_null(), Exceptions::RuntimeError,
                             "Could not construct any smoother:\n"
                                 << (triedEpetra_ ? "=> Failed to build an Epetra smoother due to the following exception:\n" : "=> Epetra and/or Ifpack are not enabled.\n")
                                 << (triedEpetra_ ? errorEpetra_ + "\n" : "")
                                 << (triedTpetra_ ? "=> Failed to build a Tpetra smoother due to the following exception:\n" : "=> Tpetra and/or Ifpack2 are not enabled.\n")
                                 << (triedTpetra_ ? errorTpetra_ + "\n" : "")
                                 << (triedBelos_ ? "=> Failed to build a Belos smoother due to the following exception:\n" : "=> Belos not enabled.\n")
                                 << (triedBelos_ ? errorBelos_ + "\n" : "")
                                 << (triedStratimikos_ ? "=> Failed to build a Stratimikos smoother due to the following exception:\n" : "=> Stratimikos not enabled.\n")
                                 << (triedStratimikos_ ? errorStratimikos_ + "\n" : ""));

  this->SetParameterList(paramList);
}

template <class Scalar, class LocalOrdinal, class GlobalOrdinal, class Node>
void TrilinosSmoother<Scalar, LocalOrdinal, GlobalOrdinal, Node>::SetFactory(const std::string& varName, const RCP<const FactoryBase>& factory) {
  // We need to propagate SetFactory to proper place
  if (!sEpetra_.is_null()) sEpetra_->SetFactory(varName, factory);
  if (!sTpetra_.is_null()) sTpetra_->SetFactory(varName, factory);
  if (!sBelos_.is_null()) sBelos_->SetFactory(varName, factory);
  if (!sStratimikos_.is_null()) sStratimikos_->SetFactory(varName, factory);
}

template <class Scalar, class LocalOrdinal, class GlobalOrdinal, class Node>
void TrilinosSmoother<Scalar, LocalOrdinal, GlobalOrdinal, Node>::DeclareInput(Level& currentLevel) const {
  if (!sBelos_.is_null())
    s_ = sBelos_;
  else if (!sStratimikos_.is_null())
    s_ = sStratimikos_;
  else {
    // Decide whether we are running in Epetra or Tpetra mode
    //
    // Theoretically, we could make this decision in the constructor, and create only
    // one of the smoothers. But we want to be able to reuse, so one can imagine a scenario
    // where one first runs hierarchy with tpetra matrix, and then with epetra.

    bool useTpetra = (currentLevel.lib() == Xpetra::UseTpetra);
    s_             = (useTpetra ? sTpetra_ : sEpetra_);
    if (s_.is_null()) {
      if (useTpetra) {
#if not defined(HAVE_MUELU_IFPACK2)
        TEUCHOS_TEST_FOR_EXCEPTION(true, Exceptions::RuntimeError,
                                   "Error: running in Tpetra mode, but MueLu with Ifpack2 was disabled during the configure stage.\n"
                                   "Please make sure that:\n"
                                   "  - Ifpack2 is enabled (Trilinos_ENABLE_Ifpack2=ON),\n"
                                   "  - Ifpack2 is available for MueLu to use (MueLu_ENABLE_Ifpack2=ON)\n");
#else
        if (triedTpetra_)
          this->GetOStream(Errors) << "Tpetra mode was disabled due to an error:\n"
                                   << errorTpetra_ << std::endl;
#endif
      }
      if (!useTpetra) {
#if not defined(HAVE_MUELU_IFPACK)
        TEUCHOS_TEST_FOR_EXCEPTION(true, Exceptions::RuntimeError,
                                   "Error: running in Epetra mode, but MueLu with Ifpack was disabled during the configure stage.\n"
                                   "Please make sure that:\n"
                                   "  - Ifpack is enabled (you can do that with Trilinos_ENABLE_Ifpack=ON),\n"
                                   "  - Ifpack is available for MueLu to use (MueLu_ENABLE_Ifpack=ON)\n");
#else
        if (triedEpetra_)
          this->GetOStream(Errors) << "Epetra mode was disabled due to an error:\n"
                                   << errorEpetra_ << std::endl;
#endif
      }
      TEUCHOS_TEST_FOR_EXCEPTION(true, Exceptions::RuntimeError,
                                 "Smoother for " << (useTpetra ? "Tpetra" : "Epetra") << " was not constructed");
    }
  }

  s_->DeclareInput(currentLevel);
}

template <class Scalar, class LocalOrdinal, class GlobalOrdinal, class Node>
void TrilinosSmoother<Scalar, LocalOrdinal, GlobalOrdinal, Node>::Setup(Level& currentLevel) {
  if (SmootherPrototype::IsSetup() == true)
    this->GetOStream(Warnings0) << "MueLu::TrilinosSmoother::Setup(): Setup() has already been called" << std::endl;

  int oldRank = s_->SetProcRankVerbose(this->GetProcRankVerbose());

  s_->Setup(currentLevel);

  s_->SetProcRankVerbose(oldRank);

  SmootherPrototype::IsSetup(true);

  this->SetParameterList(s_->GetParameterList());
}

template <class Scalar, class LocalOrdinal, class GlobalOrdinal, class Node>
void TrilinosSmoother<Scalar, LocalOrdinal, GlobalOrdinal, Node>::Apply(MultiVector& X, const MultiVector& B, bool InitialGuessIsZero) const {
  TEUCHOS_TEST_FOR_EXCEPTION(SmootherPrototype::IsSetup() == false, Exceptions::RuntimeError, "MueLu::TrilinosSmoother::Apply(): Setup() has not been called");

  s_->Apply(X, B, InitialGuessIsZero);
}

template <class Scalar, class LocalOrdinal, class GlobalOrdinal, class Node>
RCP<MueLu::SmootherPrototype<Scalar, LocalOrdinal, GlobalOrdinal, Node> >
TrilinosSmoother<Scalar, LocalOrdinal, GlobalOrdinal, Node>::Copy() const {
  RCP<TrilinosSmoother> newSmoo = rcp(new TrilinosSmoother(type_, this->GetParameterList(), overlap_));

  // We need to be quite careful with Copy
  // We still want TrilinosSmoother to follow Prototype Pattern, so we need to hide the fact that we do have some state
  if (!sEpetra_.is_null())
    newSmoo->sEpetra_ = sEpetra_->Copy();
  if (!sTpetra_.is_null())
    newSmoo->sTpetra_ = sTpetra_->Copy();
  if (!sBelos_.is_null())
    newSmoo->sBelos_ = sBelos_->Copy();
  if (!sStratimikos_.is_null())
    newSmoo->sStratimikos_ = sStratimikos_->Copy();

  // Copy the default mode
  if (s_.get() == sBelos_.get())
    newSmoo->s_ = newSmoo->sBelos_;
  else if (s_.get() == sStratimikos_.get())
    newSmoo->s_ = newSmoo->sStratimikos_;
  else if (s_.get() == sTpetra_.get())
    newSmoo->s_ = newSmoo->sTpetra_;
  else
    newSmoo->s_ = newSmoo->sEpetra_;
  newSmoo->SetParameterList(this->GetParameterList());

  return newSmoo;
}

template <class Scalar, class LocalOrdinal, class GlobalOrdinal, class Node>
std::string TrilinosSmoother<Scalar, LocalOrdinal, GlobalOrdinal, Node>::Ifpack2ToIfpack1Type(const std::string& type) {
  if (type == "RELAXATION") {
    return "point relaxation stand-alone";
  }
  if (type == "CHEBYSHEV") {
    return "Chebyshev";
  }
  if (type == "ILUT") {
    return "ILUT";
  }
  if (type == "RILUK") {
    return "ILU";
  }
  if (type == "ILU") {
    return "ILU";
  }
  if (type == "Amesos") {
    return "Amesos";
  }

  // special types

  // Note: for Ifpack there is no distinction between block and banded relaxation as there is no
  // BandedContainer or TridiagonalContainer.
  if (type == "LINESMOOTHING_BLOCKRELAXATION") {
    return "LINESMOOTHING_BLOCKRELAXATION";
  }
  if (type == "LINESMOOTHING_BLOCK RELAXATION") {
    return "LINESMOOTHING_BLOCKRELAXATION";
  }
  if (type == "LINESMOOTHING_BLOCK_RELAXATION") {
    return "LINESMOOTHING_BLOCKRELAXATION";
  }
  if (type == "LINESMOOTHING_BANDEDRELAXATION") {
    return "LINESMOOTHING_BLOCKRELAXATION";
  }
  if (type == "LINESMOOTHING_BANDED RELAXATION") {
    return "LINESMOOTHING_BLOCKRELAXATION";
  }
  if (type == "LINESMOOTHING_BANDED_RELAXATION") {
    return "LINESMOOTHING_BLOCKRELAXATION";
  }
  if (type == "LINESMOOTHING_TRIDIRELAXATION") {
    return "LINESMOOTHING_BLOCKRELAXATION";
  }
  if (type == "LINESMOOTHING_TRIDI RELAXATION") {
    return "LINESMOOTHING_BLOCKRELAXATION";
  }
  if (type == "LINESMOOTHING_TRIDI_RELAXATION") {
    return "LINESMOOTHING_BLOCKRELAXATION";
  }
  if (type == "LINESMOOTHING_TRIDIAGONALRELAXATION") {
    return "LINESMOOTHING_BLOCKRELAXATION";
  }
  if (type == "LINESMOOTHING_TRIDIAGONAL RELAXATION") {
    return "LINESMOOTHING_BLOCKRELAXATION";
  }
  if (type == "LINESMOOTHING_TRIDIAGONAL_RELAXATION") {
    return "LINESMOOTHING_BLOCKRELAXATION";
  }
  if (type == "AGGREGATE") {
    return "AGGREGATE";
  }
  if (type == "BLOCK_RELAXATION" ||
      type == "BLOCK RELAXATION" ||
      type == "BLOCKRELAXATION" ||
      // Banded
      type == "BANDED_RELAXATION" ||
      type == "BANDED RELAXATION" ||
      type == "BANDEDRELAXATION" ||
      // Tridiagonal
      type == "TRIDI_RELAXATION" ||
      type == "TRIDI RELAXATION" ||
      type == "TRIDIRELAXATION" ||
      type == "TRIDIAGONAL_RELAXATION" ||
      type == "TRIDIAGONAL RELAXATION" ||
      type == "TRIDIAGONALRELAXATION") {
    return "block relaxation stand-alone";
  }

  TEUCHOS_TEST_FOR_EXCEPTION(true, Exceptions::RuntimeError, "Cannot convert Ifpack2 preconditioner name to Ifpack: unknown type: \"" + type + "\"");
}

template <class Scalar, class LocalOrdinal, class GlobalOrdinal, class Node>
Teuchos::ParameterList TrilinosSmoother<Scalar, LocalOrdinal, GlobalOrdinal, Node>::Ifpack2ToIfpack1Param(const Teuchos::ParameterList& ifpack2List) {
  Teuchos::ParameterList ifpack1List = ifpack2List;

  if (ifpack2List.isParameter("relaxation: type") && ifpack2List.get<std::string>("relaxation: type") == "Symmetric Gauss-Seidel")
    ifpack1List.set("relaxation: type", "symmetric Gauss-Seidel");

  if (ifpack2List.isParameter("fact: iluk level-of-fill")) {
    ifpack1List.remove("fact: iluk level-of-fill");
    ifpack1List.set("fact: level-of-fill", ifpack2List.get<int>("fact: iluk level-of-fill"));
  }

  return ifpack1List;
}

template <class Scalar, class LocalOrdinal, class GlobalOrdinal, class Node>
std::string TrilinosSmoother<Scalar, LocalOrdinal, GlobalOrdinal, Node>::description() const {
  std::ostringstream out;
  if (s_ != Teuchos::null) {
    out << s_->description();
  } else {
    out << SmootherPrototype::description();
    out << "{type = " << type_ << "}";
  }
  return out.str();
}

template <class Scalar, class LocalOrdinal, class GlobalOrdinal, class Node>
void TrilinosSmoother<Scalar, LocalOrdinal, GlobalOrdinal, Node>::print(Teuchos::FancyOStream& out, const VerbLevel verbLevel) const {
  MUELU_DESCRIBE;

  if (verbLevel & Parameters0)
    out0 << "Prec. type: " << type_ << std::endl;

  if (verbLevel & Parameters1) {
    out0 << "PrecType: " << type_ << std::endl;
    out0 << "Parameter list: " << std::endl;
    Teuchos::OSTab tab2(out);
    out << this->GetParameterList();
    out0 << "Overlap: " << overlap_ << std::endl;
  }

  if (verbLevel & Debug) {
    out0 << "IsSetup: " << Teuchos::toString(SmootherPrototype::IsSetup()) << std::endl
         << "-" << std::endl
         << "Epetra PrecType: " << Ifpack2ToIfpack1Type(type_) << std::endl
         << "Epetra Parameter list: " << std::endl;
    Teuchos::OSTab tab2(out);
    out << Ifpack2ToIfpack1Param(this->GetParameterList());
    ;
  }
}

}  // namespace MueLu

#endif  // MUELU_TRILINOSSMOOTHER_DEF_HPP