CwiseUnaryView.h revision 810535bb0c575a003b32076e5352ab8fd3f23a1c 
1// This file is part of Eigen, a lightweight C++ template library
2// for linear algebra.
3//
4// Copyright (C) 2009-2010 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_CWISE_UNARY_VIEW_H
11#define EIGEN_CWISE_UNARY_VIEW_H
12
13namespace Eigen {
14
15/** \class CwiseUnaryView
16  * \ingroup Core_Module
17  *
18  * \brief Generic lvalue expression of a coefficient-wise unary operator of a matrix or a vector
19  *
20  * \param ViewOp template functor implementing the view
21  * \param MatrixType the type of the matrix we are applying the unary operator
22  *
23  * This class represents a lvalue expression of a generic unary view operator of a matrix or a vector.
24  * It is the return type of real() and imag(), and most of the time this is the only way it is used.
25  *
26  * \sa MatrixBase::unaryViewExpr(const CustomUnaryOp &) const, class CwiseUnaryOp
27  */
28
29namespace internal {
30template<typename ViewOp, typename MatrixType>
31struct traits<CwiseUnaryView<ViewOp, MatrixType> >
32 : traits<MatrixType>
33{
34  typedef typename result_of<
35                     ViewOp(typename traits<MatrixType>::Scalar)
36                   >::type Scalar;
37  typedef typename MatrixType::Nested MatrixTypeNested;
38  typedef typename remove_all<MatrixTypeNested>::type _MatrixTypeNested;
39  enum {
40    Flags = (traits<_MatrixTypeNested>::Flags & (HereditaryBits | LvalueBit | LinearAccessBit | DirectAccessBit)),
41    CoeffReadCost = traits<_MatrixTypeNested>::CoeffReadCost + functor_traits<ViewOp>::Cost,
42    MatrixTypeInnerStride =  inner_stride_at_compile_time<MatrixType>::ret,
43    // need to cast the sizeof's from size_t to int explicitly, otherwise:
44    // "error: no integral type can represent all of the enumerator values
45    InnerStrideAtCompileTime = MatrixTypeInnerStride == Dynamic
46                             ? int(Dynamic)
47                             : int(MatrixTypeInnerStride)
48                               * int(sizeof(typename traits<MatrixType>::Scalar) / sizeof(Scalar)),
49    OuterStrideAtCompileTime = outer_stride_at_compile_time<MatrixType>::ret
50  };
51};
52}
53
54template<typename ViewOp, typename MatrixType, typename StorageKind>
55class CwiseUnaryViewImpl;
56
57template<typename ViewOp, typename MatrixType>
58class CwiseUnaryView : internal::no_assignment_operator,
59  public CwiseUnaryViewImpl<ViewOp, MatrixType, typename internal::traits<MatrixType>::StorageKind>
60{
61  public:
62
63    typedef typename CwiseUnaryViewImpl<ViewOp, MatrixType,typename internal::traits<MatrixType>::StorageKind>::Base Base;
64    EIGEN_GENERIC_PUBLIC_INTERFACE(CwiseUnaryView)
65
66    inline CwiseUnaryView(const MatrixType& mat, const ViewOp& func = ViewOp())
67      : m_matrix(mat), m_functor(func) {}
68
69    EIGEN_INHERIT_ASSIGNMENT_OPERATORS(CwiseUnaryView)
70
71    EIGEN_STRONG_INLINE Index rows() const { return m_matrix.rows(); }
72    EIGEN_STRONG_INLINE Index cols() const { return m_matrix.cols(); }
73
74    /** \returns the functor representing unary operation */
75    const ViewOp& functor() const { return m_functor; }
76
77    /** \returns the nested expression */
78    const typename internal::remove_all<typename MatrixType::Nested>::type&
79    nestedExpression() const { return m_matrix; }
80
81    /** \returns the nested expression */
82    typename internal::remove_all<typename MatrixType::Nested>::type&
83    nestedExpression() { return m_matrix.const_cast_derived(); }
84
85  protected:
86    // FIXME changed from MatrixType::Nested because of a weird compilation error with sun CC
87    typename internal::nested<MatrixType>::type m_matrix;
88    ViewOp m_functor;
89};
90
91template<typename ViewOp, typename MatrixType>
92class CwiseUnaryViewImpl<ViewOp,MatrixType,Dense>
93  : public internal::dense_xpr_base< CwiseUnaryView<ViewOp, MatrixType> >::type
94{
95  public:
96
97    typedef CwiseUnaryView<ViewOp, MatrixType> Derived;
98    typedef typename internal::dense_xpr_base< CwiseUnaryView<ViewOp, MatrixType> >::type Base;
99
100    EIGEN_DENSE_PUBLIC_INTERFACE(Derived)
101
102    inline Scalar* data() { return &coeffRef(0); }
103    inline const Scalar* data() const { return &coeff(0); }
104
105    inline Index innerStride() const
106    {
107      return derived().nestedExpression().innerStride() * sizeof(typename internal::traits<MatrixType>::Scalar) / sizeof(Scalar);
108    }
109
110    inline Index outerStride() const
111    {
112      return derived().nestedExpression().outerStride();
113    }
114
115    EIGEN_STRONG_INLINE CoeffReturnType coeff(Index row, Index col) const
116    {
117      return derived().functor()(derived().nestedExpression().coeff(row, col));
118    }
119
120    EIGEN_STRONG_INLINE CoeffReturnType coeff(Index index) const
121    {
122      return derived().functor()(derived().nestedExpression().coeff(index));
123    }
124
125    EIGEN_STRONG_INLINE Scalar& coeffRef(Index row, Index col)
126    {
127      return derived().functor()(const_cast_derived().nestedExpression().coeffRef(row, col));
128    }
129
130    EIGEN_STRONG_INLINE Scalar& coeffRef(Index index)
131    {
132      return derived().functor()(const_cast_derived().nestedExpression().coeffRef(index));
133    }
134};
135
136} // end namespace Eigen
137
138#endif // EIGEN_CWISE_UNARY_VIEW_H
139