Eigen  3.2.91
SolveWithGuess.h
1 // This file is part of Eigen, a lightweight C++ template library
2 // for linear algebra.
3 //
4 // Copyright (C) 2014 Gael Guennebaud <gael.guennebaud@inria.fr>
5 //
6 // This Source Code Form is subject to the terms of the Mozilla
7 // Public License v. 2.0. If a copy of the MPL was not distributed
8 // with this file, You can obtain one at http://mozilla.org/MPL/2.0/.
9 
10 #ifndef EIGEN_SOLVEWITHGUESS_H
11 #define EIGEN_SOLVEWITHGUESS_H
12 
13 namespace Eigen {
14 
15 template<typename Decomposition, typename RhsType, typename GuessType> class SolveWithGuess;
16 
29 namespace internal {
30 
31 
32 template<typename Decomposition, typename RhsType, typename GuessType>
33 struct traits<SolveWithGuess<Decomposition, RhsType, GuessType> >
34  : traits<Solve<Decomposition,RhsType> >
35 {};
36 
37 }
38 
39 
40 template<typename Decomposition, typename RhsType, typename GuessType>
41 class SolveWithGuess : public internal::generic_xpr_base<SolveWithGuess<Decomposition,RhsType,GuessType>, MatrixXpr, typename internal::traits<RhsType>::StorageKind>::type
42 {
43 public:
44  typedef typename internal::traits<SolveWithGuess>::Scalar Scalar;
45  typedef typename internal::traits<SolveWithGuess>::PlainObject PlainObject;
46  typedef typename internal::generic_xpr_base<SolveWithGuess<Decomposition,RhsType,GuessType>, MatrixXpr, typename internal::traits<RhsType>::StorageKind>::type Base;
47 
48  SolveWithGuess(const Decomposition &dec, const RhsType &rhs, const GuessType &guess)
49  : m_dec(dec), m_rhs(rhs), m_guess(guess)
50  {}
51 
52  EIGEN_DEVICE_FUNC Index rows() const { return m_dec.cols(); }
53  EIGEN_DEVICE_FUNC Index cols() const { return m_rhs.cols(); }
54 
55  EIGEN_DEVICE_FUNC const Decomposition& dec() const { return m_dec; }
56  EIGEN_DEVICE_FUNC const RhsType& rhs() const { return m_rhs; }
57  EIGEN_DEVICE_FUNC const GuessType& guess() const { return m_guess; }
58 
59 protected:
60  const Decomposition &m_dec;
61  const RhsType &m_rhs;
62  const GuessType &m_guess;
63 
64 private:
65  Scalar coeff(Index row, Index col) const;
66  Scalar coeff(Index i) const;
67 };
68 
69 namespace internal {
70 
71 // Evaluator of SolveWithGuess -> eval into a temporary
72 template<typename Decomposition, typename RhsType, typename GuessType>
73 struct evaluator<SolveWithGuess<Decomposition,RhsType, GuessType> >
74  : public evaluator<typename SolveWithGuess<Decomposition,RhsType,GuessType>::PlainObject>
75 {
76  typedef SolveWithGuess<Decomposition,RhsType,GuessType> SolveType;
77  typedef typename SolveType::PlainObject PlainObject;
78  typedef evaluator<PlainObject> Base;
79 
80  evaluator(const SolveType& solve)
81  : m_result(solve.rows(), solve.cols())
82  {
83  ::new (static_cast<Base*>(this)) Base(m_result);
84  solve.dec()._solve_with_guess_impl(solve.rhs(), m_result, solve().guess());
85  }
86 
87 protected:
88  PlainObject m_result;
89 };
90 
91 // Specialization for "dst = dec.solveWithGuess(rhs)"
92 // NOTE we need to specialize it for Dense2Dense to avoid ambiguous specialization error and a Sparse2Sparse specialization must exist somewhere
93 template<typename DstXprType, typename DecType, typename RhsType, typename GuessType, typename Scalar>
94 struct Assignment<DstXprType, SolveWithGuess<DecType,RhsType,GuessType>, internal::assign_op<Scalar>, Dense2Dense, Scalar>
95 {
96  typedef SolveWithGuess<DecType,RhsType,GuessType> SrcXprType;
97  static void run(DstXprType &dst, const SrcXprType &src, const internal::assign_op<Scalar> &)
98  {
99  // FIXME shall we resize dst here?
100  dst = src.guess();
101  src.dec()._solve_with_guess_impl(src.rhs(), dst/*, src.guess()*/);
102  }
103 };
104 
105 } // end namepsace internal
106 
107 } // end namespace Eigen
108 
109 #endif // EIGEN_SOLVEWITHGUESS_H
Pseudo expression representing a solving operation.
Definition: SolveWithGuess.h:15
Definition: LDLT.h:16
Definition: Eigen_Colamd.h:54