EigenSolver.h

// -*- tab-width: 2; indent-tabs-mode: nil; coding: utf-8-with-signature -*-
//-----------------------------------------------------------------------------
// Copyright 2000-2025 CEA (www.cea.fr) IFPEN (www.ifpenergiesnouvelles.com)
// See the top-level COPYRIGHT file for details.
// SPDX-License-Identifier: Apache-2.0
//-----------------------------------------------------------------------------
#pragma once
 
#include <arccore/message_passing/MessagePassingGlobal.h>
#include <alien/utils/Precomp.h>
 
#include <memory>
#include <vector>
 
#include <alien/core/backend/BackEnd.h>
#include <alien/expression/solver/IEigenSolver.h>
 
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namespace Alien
{
 
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class IVector;
class IMatrix;
class IOptions;
 
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// FIXME: not implemented !
template <class Tag, typename VectorT>
class EigenProblemT : public EigenProblem
{
 public:
  EigenProblemT(IMatrix const& A)
  : EigenProblem(A)
  {}

  virtual ~EigenProblemT() {}

  typedef typename AlgebraTraits<Tag>::matrix_type KernelMatrix;
  typedef typename AlgebraTraits<Tag>::vector_type KernelVector;

  Arccore::Integer localSize() const;

  KernelMatrix const& getA() const;

  Arccore::Integer getNbEigenVectors() const { return m_eigen_vectors.size(); }

  std::vector<VectorT>& getEigenVectors() { return m_eigen_vectors; }
 
  // TOCHECK: Commentaire
  /*
  void setEigenVectors(std::vector<std::vector<Real>>& ev_vectors)
  {
    auto const& vdist = this->m_A.impl()->distribution().rowDistribution() ;
    for(auto const ev : ev_vectors)
    {
      VectorT v(vdist) ;
      Alien::LocalVectorWriter vv(v) ;
      for(auto i=0;i<vdist.localSize();++i)
      {
        vv[i] = ev[i] ;
        m_eigen_vectors.add(v) ;
      }
    }
  }*/
 
 private:
  std::vector<VectorT> m_eigen_vectors;
};
 
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template <class Tag, typename VectorT>
class GeneralizedEigenProblemT : public GeneralizedEigenProblem
{
 public:
  GeneralizedEigenProblemT(IMatrix const& A, IMatrix const& B)
  : GeneralizedEigenProblem(A, B)
  {}

  virtual ~GeneralizedEigenProblemT() {}

  typedef typename AlgebraTraits<Tag>::matrix_type KernelMatrix;
  typedef typename AlgebraTraits<Tag>::vector_type KernelVector;

  Arccore::Integer localSize() const;

  KernelMatrix const& getA() const;

  KernelMatrix const& getB() const;

  Arccore::Integer getNbEigenVectors() const { return m_eigen_vectors.size(); }

  std::vector<VectorT>& getEigenVectors() { return m_eigen_vectors; }
 
 private:
  std::vector<VectorT> m_eigen_vectors;
};
 
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template <class Tag>
class EigenSolver : public IEigenSolver
{
 public:
  typedef typename AlgebraTraits<Tag>::eigen_solver_type KernelSolver;
 
 public:
  EigenSolver(Arccore::MessagePassing::IMessagePassingMng* parallel_mng = nullptr,
              IOptions* options = nullptr);

  virtual ~EigenSolver() {}

  Arccore::String getBackEndName() const;

  void init();

  bool solve(EigenProblem& p);

  bool hasParallelSupport() const;

  const IEigenSolver::Status& getStatus() const;

  KernelSolver* implem();
 
 private:
  typedef typename AlgebraTraits<Tag>::matrix_type KernelMatrix;
  typedef typename AlgebraTraits<Tag>::vector_type KernelVector;
  std::unique_ptr<KernelSolver> m_solver;
};
 
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template <class Tag>
class GeneralizedEigenSolver : public IGeneralizedEigenSolver
{
 public:
  typedef typename AlgebraTraits<Tag>::generalized_eigen_solver_type KernelSolver;
 
 public:
  GeneralizedEigenSolver(
  IMessagePassingMng* parallel_mng = nullptr, IOptions* options = nullptr);

  virtual ~GeneralizedEigenSolver() {}

  Arccore::String getBackEndName() const;

  void init();

  bool solve(GeneralizedEigenProblem& A);

  bool hasParallelSupport() const;

  const IEigenSolver::Status& getStatus() const;

  KernelSolver* implem();
 
 private:
  typedef typename AlgebraTraits<Tag>::matrix_type KernelMatrix;
  typedef typename AlgebraTraits<Tag>::vector_type KernelVector;
  std::unique_ptr<KernelSolver> m_solver;
};
 
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} // namespace Alien
 
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