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_REPLICATE_H
11 #define EIGEN_REPLICATE_H
12 
13 namespace Eigen {
14 
15 /**
16   * \class Replicate
17   * \ingroup Core_Module
18   *
19   * \brief Expression of the multiple replication of a matrix or vector
20   *
21   * \param MatrixType the type of the object we are replicating
22   *
23   * This class represents an expression of the multiple replication of a matrix or vector.
24   * It is the return type of DenseBase::replicate() and most of the time
25   * this is the only way it is used.
26   *
27   * \sa DenseBase::replicate()
28   */
29 
30 namespace internal {
31 template<typename MatrixType,int RowFactor,int ColFactor>
32 struct traits<Replicate<MatrixType,RowFactor,ColFactor> >
33  : traits<MatrixType>
34 {
35   typedef typename MatrixType::Scalar Scalar;
36   typedef typename traits<MatrixType>::StorageKind StorageKind;
37   typedef typename traits<MatrixType>::XprKind XprKind;
38   enum {
39     Factor = (RowFactor==Dynamic || ColFactor==Dynamic) ? Dynamic : RowFactor*ColFactor
40   };
41   typedef typename nested<MatrixType,Factor>::type MatrixTypeNested;
42   typedef typename remove_reference<MatrixTypeNested>::type _MatrixTypeNested;
43   enum {
44     RowsAtCompileTime = RowFactor==Dynamic || int(MatrixType::RowsAtCompileTime)==Dynamic
45                       ? Dynamic
46                       : RowFactor * MatrixType::RowsAtCompileTime,
47     ColsAtCompileTime = ColFactor==Dynamic || int(MatrixType::ColsAtCompileTime)==Dynamic
48                       ? Dynamic
49                       : ColFactor * MatrixType::ColsAtCompileTime,
50    //FIXME we don't propagate the max sizes !!!
51     MaxRowsAtCompileTime = RowsAtCompileTime,
52     MaxColsAtCompileTime = ColsAtCompileTime,
53     IsRowMajor = MaxRowsAtCompileTime==1 && MaxColsAtCompileTime!=1 ? 1
54                : MaxColsAtCompileTime==1 && MaxRowsAtCompileTime!=1 ? 0
55                : (MatrixType::Flags & RowMajorBit) ? 1 : 0,
56     Flags = (_MatrixTypeNested::Flags & HereditaryBits & ~RowMajorBit) | (IsRowMajor ? RowMajorBit : 0),
57     CoeffReadCost = _MatrixTypeNested::CoeffReadCost
58   };
59 };
60 }
61 
62 template<typename MatrixType,int RowFactor,int ColFactor> class Replicate
63   : public internal::dense_xpr_base< Replicate<MatrixType,RowFactor,ColFactor> >::type
64 {
65     typedef typename internal::traits<Replicate>::MatrixTypeNested MatrixTypeNested;
66     typedef typename internal::traits<Replicate>::_MatrixTypeNested _MatrixTypeNested;
67   public:
68 
69     typedef typename internal::dense_xpr_base<Replicate>::type Base;
70     EIGEN_DENSE_PUBLIC_INTERFACE(Replicate)
71 
72     template<typename OriginalMatrixType>
73     inline explicit Replicate(const OriginalMatrixType& a_matrix)
74       : m_matrix(a_matrix), m_rowFactor(RowFactor), m_colFactor(ColFactor)
75     {
76       EIGEN_STATIC_ASSERT((internal::is_same<typename internal::remove_const<MatrixType>::type,OriginalMatrixType>::value),
77                           THE_MATRIX_OR_EXPRESSION_THAT_YOU_PASSED_DOES_NOT_HAVE_THE_EXPECTED_TYPE)
78       eigen_assert(RowFactor!=Dynamic && ColFactor!=Dynamic);
79     }
80 
81     template<typename OriginalMatrixType>
82     inline Replicate(const OriginalMatrixType& a_matrix, Index rowFactor, Index colFactor)
83       : m_matrix(a_matrix), m_rowFactor(rowFactor), m_colFactor(colFactor)
84     {
85       EIGEN_STATIC_ASSERT((internal::is_same<typename internal::remove_const<MatrixType>::type,OriginalMatrixType>::value),
86                           THE_MATRIX_OR_EXPRESSION_THAT_YOU_PASSED_DOES_NOT_HAVE_THE_EXPECTED_TYPE)
87     }
88 
89     inline Index rows() const { return m_matrix.rows() * m_rowFactor.value(); }
90     inline Index cols() const { return m_matrix.cols() * m_colFactor.value(); }
91 
92     inline Scalar coeff(Index rowId, Index colId) const
93     {
94       // try to avoid using modulo; this is a pure optimization strategy
95       const Index actual_row  = internal::traits<MatrixType>::RowsAtCompileTime==1 ? 0
96                             : RowFactor==1 ? rowId
97                             : rowId%m_matrix.rows();
98       const Index actual_col  = internal::traits<MatrixType>::ColsAtCompileTime==1 ? 0
99                             : ColFactor==1 ? colId
100                             : colId%m_matrix.cols();
101 
102       return m_matrix.coeff(actual_row, actual_col);
103     }
104     template<int LoadMode>
105     inline PacketScalar packet(Index rowId, Index colId) const
106     {
107       const Index actual_row  = internal::traits<MatrixType>::RowsAtCompileTime==1 ? 0
108                             : RowFactor==1 ? rowId
109                             : rowId%m_matrix.rows();
110       const Index actual_col  = internal::traits<MatrixType>::ColsAtCompileTime==1 ? 0
111                             : ColFactor==1 ? colId
112                             : colId%m_matrix.cols();
113 
114       return m_matrix.template packet<LoadMode>(actual_row, actual_col);
115     }
116 
117     const _MatrixTypeNested& nestedExpression() const
118     {
119       return m_matrix;
120     }
121 
122   protected:
123     MatrixTypeNested m_matrix;
124     const internal::variable_if_dynamic<Index, RowFactor> m_rowFactor;
125     const internal::variable_if_dynamic<Index, ColFactor> m_colFactor;
126 };
127 
128 /**
129   * \return an expression of the replication of \c *this
130   *
131   * Example: \include MatrixBase_replicate.cpp
132   * Output: \verbinclude MatrixBase_replicate.out
133   *
134   * \sa VectorwiseOp::replicate(), DenseBase::replicate(Index,Index), class Replicate
135   */
136 template<typename Derived>
137 template<int RowFactor, int ColFactor>
138 const Replicate<Derived,RowFactor,ColFactor>
139 DenseBase<Derived>::replicate() const
140 {
141   return Replicate<Derived,RowFactor,ColFactor>(derived());
142 }
143 
144 /**
145   * \return an expression of the replication of \c *this
146   *
147   * Example: \include MatrixBase_replicate_int_int.cpp
148   * Output: \verbinclude MatrixBase_replicate_int_int.out
149   *
150   * \sa VectorwiseOp::replicate(), DenseBase::replicate<int,int>(), class Replicate
151   */
152 template<typename Derived>
153 const typename DenseBase<Derived>::ReplicateReturnType
154 DenseBase<Derived>::replicate(Index rowFactor,Index colFactor) const
155 {
156   return Replicate<Derived,Dynamic,Dynamic>(derived(),rowFactor,colFactor);
157 }
158 
159 /**
160   * \return an expression of the replication of each column (or row) of \c *this
161   *
162   * Example: \include DirectionWise_replicate_int.cpp
163   * Output: \verbinclude DirectionWise_replicate_int.out
164   *
165   * \sa VectorwiseOp::replicate(), DenseBase::replicate(), class Replicate
166   */
167 template<typename ExpressionType, int Direction>
168 const typename VectorwiseOp<ExpressionType,Direction>::ReplicateReturnType
169 VectorwiseOp<ExpressionType,Direction>::replicate(Index factor) const
170 {
171   return typename VectorwiseOp<ExpressionType,Direction>::ReplicateReturnType
172           (_expression(),Direction==Vertical?factor:1,Direction==Horizontal?factor:1);
173 }
174 
175 } // end namespace Eigen
176 
177 #endif // EIGEN_REPLICATE_H
178