mirror of
https://gitlab.com/libeigen/eigen.git
synced 2025-04-29 15:24:51 +08:00
118 lines
4.1 KiB
C++
118 lines
4.1 KiB
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_SOLVEWITHGUESS_H
|
|
#define EIGEN_SOLVEWITHGUESS_H
|
|
|
|
namespace Eigen {
|
|
|
|
template<typename Decomposition, typename RhsType, typename GuessType> class SolveWithGuess;
|
|
|
|
/** \class SolveWithGuess
|
|
* \ingroup IterativeLinearSolvers_Module
|
|
*
|
|
* \brief Pseudo expression representing a solving operation
|
|
*
|
|
* \tparam Decomposition the type of the matrix or decomposion object
|
|
* \tparam Rhstype the type of the right-hand side
|
|
*
|
|
* This class represents an expression of A.solve(B)
|
|
* and most of the time this is the only way it is used.
|
|
*
|
|
*/
|
|
namespace internal {
|
|
|
|
|
|
template<typename Decomposition, typename RhsType, typename GuessType>
|
|
struct traits<SolveWithGuess<Decomposition, RhsType, GuessType> >
|
|
: traits<Solve<Decomposition,RhsType> >
|
|
{};
|
|
|
|
}
|
|
|
|
|
|
template<typename Decomposition, typename RhsType, typename GuessType>
|
|
class SolveWithGuess : public internal::generic_xpr_base<SolveWithGuess<Decomposition,RhsType,GuessType>, MatrixXpr, typename internal::traits<RhsType>::StorageKind>::type
|
|
{
|
|
public:
|
|
typedef typename internal::traits<SolveWithGuess>::Scalar Scalar;
|
|
typedef typename internal::traits<SolveWithGuess>::PlainObject PlainObject;
|
|
typedef typename internal::generic_xpr_base<SolveWithGuess<Decomposition,RhsType,GuessType>, MatrixXpr, typename internal::traits<RhsType>::StorageKind>::type Base;
|
|
typedef typename internal::ref_selector<SolveWithGuess>::type Nested;
|
|
|
|
SolveWithGuess(const Decomposition &dec, const RhsType &rhs, const GuessType &guess)
|
|
: m_dec(dec), m_rhs(rhs), m_guess(guess)
|
|
{}
|
|
|
|
EIGEN_DEVICE_FUNC EIGEN_CONSTEXPR
|
|
Index rows() const EIGEN_NOEXCEPT { return m_dec.cols(); }
|
|
EIGEN_DEVICE_FUNC EIGEN_CONSTEXPR
|
|
Index cols() const EIGEN_NOEXCEPT { return m_rhs.cols(); }
|
|
|
|
EIGEN_DEVICE_FUNC const Decomposition& dec() const { return m_dec; }
|
|
EIGEN_DEVICE_FUNC const RhsType& rhs() const { return m_rhs; }
|
|
EIGEN_DEVICE_FUNC const GuessType& guess() const { return m_guess; }
|
|
|
|
protected:
|
|
const Decomposition &m_dec;
|
|
const RhsType &m_rhs;
|
|
const GuessType &m_guess;
|
|
|
|
private:
|
|
Scalar coeff(Index row, Index col) const;
|
|
Scalar coeff(Index i) const;
|
|
};
|
|
|
|
namespace internal {
|
|
|
|
// Evaluator of SolveWithGuess -> eval into a temporary
|
|
template<typename Decomposition, typename RhsType, typename GuessType>
|
|
struct evaluator<SolveWithGuess<Decomposition,RhsType, GuessType> >
|
|
: public evaluator<typename SolveWithGuess<Decomposition,RhsType,GuessType>::PlainObject>
|
|
{
|
|
typedef SolveWithGuess<Decomposition,RhsType,GuessType> SolveType;
|
|
typedef typename SolveType::PlainObject PlainObject;
|
|
typedef evaluator<PlainObject> Base;
|
|
|
|
evaluator(const SolveType& solve)
|
|
: m_result(solve.rows(), solve.cols())
|
|
{
|
|
::new (static_cast<Base*>(this)) Base(m_result);
|
|
m_result = solve.guess();
|
|
solve.dec()._solve_with_guess_impl(solve.rhs(), m_result);
|
|
}
|
|
|
|
protected:
|
|
PlainObject m_result;
|
|
};
|
|
|
|
// Specialization for "dst = dec.solveWithGuess(rhs)"
|
|
// NOTE we need to specialize it for Dense2Dense to avoid ambiguous specialization error and a Sparse2Sparse specialization must exist somewhere
|
|
template<typename DstXprType, typename DecType, typename RhsType, typename GuessType, typename Scalar>
|
|
struct Assignment<DstXprType, SolveWithGuess<DecType,RhsType,GuessType>, internal::assign_op<Scalar,Scalar>, Dense2Dense>
|
|
{
|
|
typedef SolveWithGuess<DecType,RhsType,GuessType> SrcXprType;
|
|
static void run(DstXprType &dst, const SrcXprType &src, const internal::assign_op<Scalar,Scalar> &)
|
|
{
|
|
Index dstRows = src.rows();
|
|
Index dstCols = src.cols();
|
|
if((dst.rows()!=dstRows) || (dst.cols()!=dstCols))
|
|
dst.resize(dstRows, dstCols);
|
|
|
|
dst = src.guess();
|
|
src.dec()._solve_with_guess_impl(src.rhs(), dst/*, src.guess()*/);
|
|
}
|
|
};
|
|
|
|
} // end namespace internal
|
|
|
|
} // end namespace Eigen
|
|
|
|
#endif // EIGEN_SOLVEWITHGUESS_H
|