1// This file is part of Eigen, a lightweight C++ template library
2// for linear algebra.
3//
4// Copyright (C) 2010 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_SPARSE_SOLVE_H
11#define EIGEN_SPARSE_SOLVE_H
12
13namespace Eigen {
14
15namespace internal {
16
17template<typename _DecompositionType, typename Rhs> struct sparse_solve_retval_base;
18template<typename _DecompositionType, typename Rhs> struct sparse_solve_retval;
19
20template<typename DecompositionType, typename Rhs>
21struct traits<sparse_solve_retval_base<DecompositionType, Rhs> >
22{
23  typedef typename DecompositionType::MatrixType MatrixType;
24  typedef SparseMatrix<typename Rhs::Scalar, Rhs::Options, typename Rhs::Index> ReturnType;
25};
26
27template<typename _DecompositionType, typename Rhs> struct sparse_solve_retval_base
28 : public ReturnByValue<sparse_solve_retval_base<_DecompositionType, Rhs> >
29{
30  typedef typename remove_all<typename Rhs::Nested>::type RhsNestedCleaned;
31  typedef _DecompositionType DecompositionType;
32  typedef ReturnByValue<sparse_solve_retval_base> Base;
33  typedef typename Base::Index Index;
34
35  sparse_solve_retval_base(const DecompositionType& dec, const Rhs& rhs)
36    : m_dec(dec), m_rhs(rhs)
37  {}
38
39  inline Index rows() const { return m_dec.cols(); }
40  inline Index cols() const { return m_rhs.cols(); }
41  inline const DecompositionType& dec() const { return m_dec; }
42  inline const RhsNestedCleaned& rhs() const { return m_rhs; }
43
44  template<typename Dest> inline void evalTo(Dest& dst) const
45  {
46    static_cast<const sparse_solve_retval<DecompositionType,Rhs>*>(this)->evalTo(dst);
47  }
48
49  protected:
50    template<typename DestScalar, int DestOptions, typename DestIndex>
51    inline void defaultEvalTo(SparseMatrix<DestScalar,DestOptions,DestIndex>& dst) const
52    {
53      // we process the sparse rhs per block of NbColsAtOnce columns temporarily stored into a dense matrix.
54      static const int NbColsAtOnce = 4;
55      int rhsCols = m_rhs.cols();
56      int size = m_rhs.rows();
57      Eigen::Matrix<DestScalar,Dynamic,Dynamic> tmp(size,rhsCols);
58      Eigen::Matrix<DestScalar,Dynamic,Dynamic> tmpX(size,rhsCols);
59      for(int k=0; k<rhsCols; k+=NbColsAtOnce)
60      {
61        int actualCols = std::min<int>(rhsCols-k, NbColsAtOnce);
62        tmp.leftCols(actualCols) = m_rhs.middleCols(k,actualCols);
63        tmpX.leftCols(actualCols) = m_dec.solve(tmp.leftCols(actualCols));
64        dst.middleCols(k,actualCols) = tmpX.leftCols(actualCols).sparseView();
65      }
66    }
67    const DecompositionType& m_dec;
68    typename Rhs::Nested m_rhs;
69};
70
71#define EIGEN_MAKE_SPARSE_SOLVE_HELPERS(DecompositionType,Rhs) \
72  typedef typename DecompositionType::MatrixType MatrixType; \
73  typedef typename MatrixType::Scalar Scalar; \
74  typedef typename MatrixType::RealScalar RealScalar; \
75  typedef typename MatrixType::Index Index; \
76  typedef Eigen::internal::sparse_solve_retval_base<DecompositionType,Rhs> Base; \
77  using Base::dec; \
78  using Base::rhs; \
79  using Base::rows; \
80  using Base::cols; \
81  sparse_solve_retval(const DecompositionType& dec, const Rhs& rhs) \
82    : Base(dec, rhs) {}
83
84
85
86template<typename DecompositionType, typename Rhs, typename Guess> struct solve_retval_with_guess;
87
88template<typename DecompositionType, typename Rhs, typename Guess>
89struct traits<solve_retval_with_guess<DecompositionType, Rhs, Guess> >
90{
91  typedef typename DecompositionType::MatrixType MatrixType;
92  typedef Matrix<typename Rhs::Scalar,
93                 MatrixType::ColsAtCompileTime,
94                 Rhs::ColsAtCompileTime,
95                 Rhs::PlainObject::Options,
96                 MatrixType::MaxColsAtCompileTime,
97                 Rhs::MaxColsAtCompileTime> ReturnType;
98};
99
100template<typename DecompositionType, typename Rhs, typename Guess> struct solve_retval_with_guess
101 : public ReturnByValue<solve_retval_with_guess<DecompositionType, Rhs, Guess> >
102{
103  typedef typename DecompositionType::Index Index;
104
105  solve_retval_with_guess(const DecompositionType& dec, const Rhs& rhs, const Guess& guess)
106    : m_dec(dec), m_rhs(rhs), m_guess(guess)
107  {}
108
109  inline Index rows() const { return m_dec.cols(); }
110  inline Index cols() const { return m_rhs.cols(); }
111
112  template<typename Dest> inline void evalTo(Dest& dst) const
113  {
114    dst = m_guess;
115    m_dec._solveWithGuess(m_rhs,dst);
116  }
117
118  protected:
119    const DecompositionType& m_dec;
120    const typename Rhs::Nested m_rhs;
121    const typename Guess::Nested m_guess;
122};
123
124} // namepsace internal
125
126} // end namespace Eigen
127
128#endif // EIGEN_SPARSE_SOLVE_H
129