Quelle SparseSolverBase.h Sprache: C

// This file is part of Eigen, a lightweight C++ template library
// for linear algebra.
//
// Copyright (C) 2014 Gael Guennebaud <gael.guennebaud@inria.fr>
//
// This Source Code Form is subject to the terms of the Mozilla
// Public License v. 2.0. If a copy of the MPL was not distributed
// with this file, You can obtain one at http://mozilla.org/MPL/2.0/.

#ifndef EIGEN_SPARSESOLVERBASE_H
#define EIGEN_SPARSESOLVERBASE_H

namespace Eigen {

namespace internal {

  /** \internal
  * Helper functions to solve with a sparse right-hand-side and result.
  * The rhs is decomposed into small vertical panels which are solved through dense temporaries.
  */
template<typename Decomposition, typename Rhs, typename Dest>
typename enable_if<Rhs::ColsAtCompileTime!=1 && Dest::ColsAtCompileTime!=1>::type
solve_sparse_through_dense_panels(const Decomposition &dec, const Rhs& rhs, Dest &dest)
{
  EIGEN_STATIC_ASSERT((Dest::Flags&RowMajorBit)==0,THIS_METHOD_IS_ONLY_FOR_COLUMN_MAJOR_MATRICES);
  typedef typename Dest::Scalar DestScalar;
  // we process the sparse rhs per block of NbColsAtOnce columns temporarily stored into a dense matrix.
  static const Index NbColsAtOnce = 4;
  Index rhsCols = rhs.cols();
  Index size = rhs.rows();
  // the temporary matrices do not need more columns than NbColsAtOnce:
  Index tmpCols = (std::min)(rhsCols, NbColsAtOnce);
  Eigen::Matrix<DestScalar,Dynamic,Dynamic> tmp(size,tmpCols);
  Eigen::Matrix<DestScalar,Dynamic,Dynamic> tmpX(size,tmpCols);
  for(Index k=0; k<rhsCols; k+=NbColsAtOnce)
  {
    Index actualCols = std::min<Index>(rhsCols-k, NbColsAtOnce);
    tmp.leftCols(actualCols) = rhs.middleCols(k,actualCols);
    tmpX.leftCols(actualCols) = dec.solve(tmp.leftCols(actualCols));
    dest.middleCols(k,actualCols) = tmpX.leftCols(actualCols).sparseView();
  }
}

// Overload for vector as rhs
template<typename Decomposition, typename Rhs, typename Dest>
typename enable_if<Rhs::ColsAtCompileTime==1 || Dest::ColsAtCompileTime==1>::type
solve_sparse_through_dense_panels(const Decomposition &dec, const Rhs& rhs, Dest &dest)
{
  typedef typename Dest::Scalar DestScalar;
  Index size = rhs.rows();
  Eigen::Matrix<DestScalar,Dynamic,1> rhs_dense(rhs);
  Eigen::Matrix<DestScalar,Dynamic,1> dest_dense(size);
  dest_dense = dec.solve(rhs_dense);
  dest = dest_dense.sparseView();
}

} // end namespace internal

/** \class SparseSolverBase
  * \ingroup SparseCore_Module
  * \brief A base class for sparse solvers
  *
  * \tparam Derived the actual type of the solver.
  *
  */
template<typename Derived>
class SparseSolverBase : internal::noncopyable
{
  public:

    /** Default constructor */
    SparseSolverBase()
      : m_isInitialized(false)
    {}

    ~SparseSolverBase()
    {}

    Derived& derived() { return *static_cast<Derived*>(this); }
    const Derived& derived() const { return *static_cast<const Derived*>(this); }

    /** \returns an expression of the solution x of \f$ A x = b \f$ using the current decomposition of A.
      *
      * \sa compute()
      */
    template<typename Rhs>
    inline const Solve<Derived, Rhs>
    solve(const MatrixBase<Rhs>& b) const
    {
      eigen_assert(m_isInitialized && "Solver is not initialized.");
      eigen_assert(derived().rows()==b.rows() && "solve(): invalid number of rows of the right hand side matrix b");
      return Solve<Derived, Rhs>(derived(), b.derived());
    }

    /** \returns an expression of the solution x of \f$ A x = b \f$ using the current decomposition of A.
      *
      * \sa compute()
      */
    template<typename Rhs>
    inline const Solve<Derived, Rhs>
    solve(const SparseMatrixBase<Rhs>& b) const
    {
      eigen_assert(m_isInitialized && "Solver is not initialized.");
      eigen_assert(derived().rows()==b.rows() && "solve(): invalid number of rows of the right hand side matrix b");
      return Solve<Derived, Rhs>(derived(), b.derived());
    }

    #ifndef EIGEN_PARSED_BY_DOXYGEN
    /** \internal default implementation of solving with a sparse rhs */
    template<typename Rhs,typename Dest>
    void _solve_impl(const SparseMatrixBase<Rhs> &b, SparseMatrixBase<Dest> &dest) const
    {
      internal::solve_sparse_through_dense_panels(derived(), b.derived(), dest.derived());
    }
    #endif // EIGEN_PARSED_BY_DOXYGEN

  protected:

    mutable bool m_isInitialized;
};

} // end namespace Eigen

#endif // EIGEN_SPARSESOLVERBASE_H

quality95%

¤ Dauer der Verarbeitung: 0.16 Sekunden (vorverarbeitet) ¤

Wurzel

Suchen

Beweissystem der NASA

Beweissystem Isabelle

NIST Cobol Testsuite

Cephes Mathematical Library

Wiener Entwicklungsmethode

Haftungshinweis

Die Informationen auf dieser Webseite wurden nach bestem Wissen sorgfältig zusammengestellt. Es wird jedoch weder Vollständigkeit, noch Richtigkeit, noch Qualität der bereit gestellten Informationen zugesichert.

Bemerkung:

Die farbliche Syntaxdarstellung ist noch experimentell.