SparseView.h revision 7faaa9f3f0df9d23790277834d426c3d992ac3ba 
1// This file is part of Eigen, a lightweight C++ template library
2// for linear algebra.
3//
4// Copyright (C) 2011 Gael Guennebaud <gael.guennebaud@inria.fr>
5// Copyright (C) 2010 Daniel Lowengrub <lowdanie@gmail.com>
6//
7// This Source Code Form is subject to the terms of the Mozilla
8// Public License v. 2.0. If a copy of the MPL was not distributed
9// with this file, You can obtain one at http://mozilla.org/MPL/2.0/.
10
11#ifndef EIGEN_SPARSEVIEW_H
12#define EIGEN_SPARSEVIEW_H
13
14namespace Eigen {
15
16namespace internal {
17
18template<typename MatrixType>
19struct traits<SparseView<MatrixType> > : traits<MatrixType>
20{
21  typedef typename MatrixType::Index Index;
22  typedef Sparse StorageKind;
23  enum {
24    Flags = int(traits<MatrixType>::Flags) & (RowMajorBit)
25  };
26};
27
28} // end namespace internal
29
30template<typename MatrixType>
31class SparseView : public SparseMatrixBase<SparseView<MatrixType> >
32{
33  typedef typename MatrixType::Nested MatrixTypeNested;
34  typedef typename internal::remove_all<MatrixTypeNested>::type _MatrixTypeNested;
35public:
36  EIGEN_SPARSE_PUBLIC_INTERFACE(SparseView)
37
38  SparseView(const MatrixType& mat, const Scalar& m_reference = Scalar(0),
39             typename NumTraits<Scalar>::Real m_epsilon = NumTraits<Scalar>::dummy_precision()) :
40    m_matrix(mat), m_reference(m_reference), m_epsilon(m_epsilon) {}
41
42  class InnerIterator;
43
44  inline Index rows() const { return m_matrix.rows(); }
45  inline Index cols() const { return m_matrix.cols(); }
46
47  inline Index innerSize() const { return m_matrix.innerSize(); }
48  inline Index outerSize() const { return m_matrix.outerSize(); }
49
50protected:
51  MatrixTypeNested m_matrix;
52  Scalar m_reference;
53  typename NumTraits<Scalar>::Real m_epsilon;
54};
55
56template<typename MatrixType>
57class SparseView<MatrixType>::InnerIterator : public _MatrixTypeNested::InnerIterator
58{
59  typedef typename SparseView::Index Index;
60public:
61  typedef typename _MatrixTypeNested::InnerIterator IterBase;
62  InnerIterator(const SparseView& view, Index outer) :
63  IterBase(view.m_matrix, outer), m_view(view)
64  {
65    incrementToNonZero();
66  }
67
68  EIGEN_STRONG_INLINE InnerIterator& operator++()
69  {
70    IterBase::operator++();
71    incrementToNonZero();
72    return *this;
73  }
74
75  using IterBase::value;
76
77protected:
78  const SparseView& m_view;
79
80private:
81  void incrementToNonZero()
82  {
83    while((bool(*this)) && internal::isMuchSmallerThan(value(), m_view.m_reference, m_view.m_epsilon))
84    {
85      IterBase::operator++();
86    }
87  }
88};
89
90template<typename Derived>
91const SparseView<Derived> MatrixBase<Derived>::sparseView(const Scalar& m_reference,
92                                                          const typename NumTraits<Scalar>::Real& m_epsilon) const
93{
94  return SparseView<Derived>(derived(), m_reference, m_epsilon);
95}
96
97} // end namespace Eigen
98
99#endif
100