Eigen  3.3.7
Solve.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_SOLVE_H
11 #define EIGEN_SOLVE_H
12 
13 namespace Eigen {
14 
15 template<typename Decomposition, typename RhsType, typename StorageKind> class SolveImpl;
16 
29 namespace internal {
30 
31 // this solve_traits class permits to determine the evaluation type with respect to storage kind (Dense vs Sparse)
32 template<typename Decomposition, typename RhsType,typename StorageKind> struct solve_traits;
33 
34 template<typename Decomposition, typename RhsType>
35 struct solve_traits<Decomposition,RhsType,Dense>
36 {
37  typedef typename make_proper_matrix_type<typename RhsType::Scalar,
38  Decomposition::ColsAtCompileTime,
39  RhsType::ColsAtCompileTime,
40  RhsType::PlainObject::Options,
41  Decomposition::MaxColsAtCompileTime,
42  RhsType::MaxColsAtCompileTime>::type PlainObject;
43 };
44 
45 template<typename Decomposition, typename RhsType>
46 struct traits<Solve<Decomposition, RhsType> >
47  : traits<typename solve_traits<Decomposition,RhsType,typename internal::traits<RhsType>::StorageKind>::PlainObject>
48 {
49  typedef typename solve_traits<Decomposition,RhsType,typename internal::traits<RhsType>::StorageKind>::PlainObject PlainObject;
50  typedef typename promote_index_type<typename Decomposition::StorageIndex, typename RhsType::StorageIndex>::type StorageIndex;
51  typedef traits<PlainObject> BaseTraits;
52  enum {
53  Flags = BaseTraits::Flags & RowMajorBit,
54  CoeffReadCost = HugeCost
55  };
56 };
57 
58 }
59 
60 
61 template<typename Decomposition, typename RhsType>
62 class Solve : public SolveImpl<Decomposition,RhsType,typename internal::traits<RhsType>::StorageKind>
63 {
64 public:
65  typedef typename internal::traits<Solve>::PlainObject PlainObject;
66  typedef typename internal::traits<Solve>::StorageIndex StorageIndex;
67 
68  Solve(const Decomposition &dec, const RhsType &rhs)
69  : m_dec(dec), m_rhs(rhs)
70  {}
71 
72  EIGEN_DEVICE_FUNC Index rows() const { return m_dec.cols(); }
73  EIGEN_DEVICE_FUNC Index cols() const { return m_rhs.cols(); }
74 
75  EIGEN_DEVICE_FUNC const Decomposition& dec() const { return m_dec; }
76  EIGEN_DEVICE_FUNC const RhsType& rhs() const { return m_rhs; }
77 
78 protected:
79  const Decomposition &m_dec;
80  const RhsType &m_rhs;
81 };
82 
83 
84 // Specialization of the Solve expression for dense results
85 template<typename Decomposition, typename RhsType>
86 class SolveImpl<Decomposition,RhsType,Dense>
87  : public MatrixBase<Solve<Decomposition,RhsType> >
88 {
89  typedef Solve<Decomposition,RhsType> Derived;
90 
91 public:
92 
94  EIGEN_DENSE_PUBLIC_INTERFACE(Derived)
95 
96 private:
97 
98  Scalar coeff(Index row, Index col) const;
99  Scalar coeff(Index i) const;
100 };
101 
102 // Generic API dispatcher
103 template<typename Decomposition, typename RhsType, typename StorageKind>
104 class SolveImpl : public internal::generic_xpr_base<Solve<Decomposition,RhsType>, MatrixXpr, StorageKind>::type
105 {
106  public:
107  typedef typename internal::generic_xpr_base<Solve<Decomposition,RhsType>, MatrixXpr, StorageKind>::type Base;
108 };
109 
110 namespace internal {
111 
112 // Evaluator of Solve -> eval into a temporary
113 template<typename Decomposition, typename RhsType>
114 struct evaluator<Solve<Decomposition,RhsType> >
115  : public evaluator<typename Solve<Decomposition,RhsType>::PlainObject>
116 {
117  typedef Solve<Decomposition,RhsType> SolveType;
118  typedef typename SolveType::PlainObject PlainObject;
119  typedef evaluator<PlainObject> Base;
120 
121  enum { Flags = Base::Flags | EvalBeforeNestingBit };
122 
123  EIGEN_DEVICE_FUNC explicit evaluator(const SolveType& solve)
124  : m_result(solve.rows(), solve.cols())
125  {
126  ::new (static_cast<Base*>(this)) Base(m_result);
127  solve.dec()._solve_impl(solve.rhs(), m_result);
128  }
129 
130 protected:
131  PlainObject m_result;
132 };
133 
134 // Specialization for "dst = dec.solve(rhs)"
135 // NOTE we need to specialize it for Dense2Dense to avoid ambiguous specialization error and a Sparse2Sparse specialization must exist somewhere
136 template<typename DstXprType, typename DecType, typename RhsType, typename Scalar>
137 struct Assignment<DstXprType, Solve<DecType,RhsType>, internal::assign_op<Scalar,Scalar>, Dense2Dense>
138 {
139  typedef Solve<DecType,RhsType> SrcXprType;
140  static void run(DstXprType &dst, const SrcXprType &src, const internal::assign_op<Scalar,Scalar> &)
141  {
142  Index dstRows = src.rows();
143  Index dstCols = src.cols();
144  if((dst.rows()!=dstRows) || (dst.cols()!=dstCols))
145  dst.resize(dstRows, dstCols);
146 
147  src.dec()._solve_impl(src.rhs(), dst);
148  }
149 };
150 
151 // Specialization for "dst = dec.transpose().solve(rhs)"
152 template<typename DstXprType, typename DecType, typename RhsType, typename Scalar>
153 struct Assignment<DstXprType, Solve<Transpose<const DecType>,RhsType>, internal::assign_op<Scalar,Scalar>, Dense2Dense>
154 {
155  typedef Solve<Transpose<const DecType>,RhsType> SrcXprType;
156  static void run(DstXprType &dst, const SrcXprType &src, const internal::assign_op<Scalar,Scalar> &)
157  {
158  Index dstRows = src.rows();
159  Index dstCols = src.cols();
160  if((dst.rows()!=dstRows) || (dst.cols()!=dstCols))
161  dst.resize(dstRows, dstCols);
162 
163  src.dec().nestedExpression().template _solve_impl_transposed<false>(src.rhs(), dst);
164  }
165 };
166 
167 // Specialization for "dst = dec.adjoint().solve(rhs)"
168 template<typename DstXprType, typename DecType, typename RhsType, typename Scalar>
169 struct Assignment<DstXprType, Solve<CwiseUnaryOp<internal::scalar_conjugate_op<typename DecType::Scalar>, const Transpose<const DecType> >,RhsType>,
170  internal::assign_op<Scalar,Scalar>, Dense2Dense>
171 {
172  typedef Solve<CwiseUnaryOp<internal::scalar_conjugate_op<typename DecType::Scalar>, const Transpose<const DecType> >,RhsType> SrcXprType;
173  static void run(DstXprType &dst, const SrcXprType &src, const internal::assign_op<Scalar,Scalar> &)
174  {
175  Index dstRows = src.rows();
176  Index dstCols = src.cols();
177  if((dst.rows()!=dstRows) || (dst.cols()!=dstCols))
178  dst.resize(dstRows, dstCols);
179 
180  src.dec().nestedExpression().nestedExpression().template _solve_impl_transposed<true>(src.rhs(), dst);
181  }
182 };
183 
184 } // end namepsace internal
185 
186 } // end namespace Eigen
187 
188 #endif // EIGEN_SOLVE_H
Eigen::HugeCost
const int HugeCost
Definition: Constants.h:39
Eigen
Namespace containing all symbols from the Eigen library.
Definition: Core:306
Eigen::RowMajorBit
const unsigned int RowMajorBit
Definition: Constants.h:61
Eigen::Solve
Pseudo expression representing a solving operation.
Definition: Solve.h:62
Eigen::MatrixBase
Base class for all dense matrices, vectors, and expressions.
Definition: MatrixBase.h:48
Eigen::EvalBeforeNestingBit
const unsigned int EvalBeforeNestingBit
Definition: Constants.h:65
Eigen::Index
EIGEN_DEFAULT_DENSE_INDEX_TYPE Index
The Index type as used for the API.
Definition: Meta.h:33
Eigen::Dense
Definition: Constants.h:491