mirror of
https://gitlab.com/libeigen/eigen.git
synced 2025-04-29 07:14:12 +08:00
112 lines
4.3 KiB
C++
112 lines
4.3 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
|
|
|
|
// IWYU pragma: private
|
|
#include "./InternalHeaderCheck.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 decomposition 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> > {};
|
|
|
|
} // namespace internal
|
|
|
|
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 constexpr Index rows() const EIGEN_NOEXCEPT { return m_dec.cols(); }
|
|
EIGEN_DEVICE_FUNC 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()) {
|
|
internal::construct_at<Base>(this, 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
|