Michael Ernst Peter / Eigen

src/Core/Reverse.h@1:3b8049da21b8, 2019-09-24 (annotated)

Committer:
jsoh91
Date:
Tue Sep 24 00:18:23 2019 +0000
Revision:
1:3b8049da21b8
Parent:
0:13a5d365ba16 
ignore and revise some of error parts

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ykuroda 0:13a5d365ba16 1 // This file is part of Eigen, a lightweight C++ template library
ykuroda 0:13a5d365ba16 2 // for linear algebra.
ykuroda 0:13a5d365ba16 3 //
ykuroda 0:13a5d365ba16 4 // Copyright (C) 2006-2008 Benoit Jacob <jacob.benoit.1@gmail.com>
ykuroda 0:13a5d365ba16 5 // Copyright (C) 2009 Ricard Marxer <email@ricardmarxer.com>
ykuroda 0:13a5d365ba16 6 // Copyright (C) 2009-2010 Gael Guennebaud <gael.guennebaud@inria.fr>
ykuroda 0:13a5d365ba16 7 //
ykuroda 0:13a5d365ba16 8 // This Source Code Form is subject to the terms of the Mozilla
ykuroda 0:13a5d365ba16 9 // Public License v. 2.0. If a copy of the MPL was not distributed
ykuroda 0:13a5d365ba16 10 // with this file, You can obtain one at http://mozilla.org/MPL/2.0/.
ykuroda 0:13a5d365ba16 11
ykuroda 0:13a5d365ba16 12 #ifndef EIGEN_REVERSE_H
ykuroda 0:13a5d365ba16 13 #define EIGEN_REVERSE_H
ykuroda 0:13a5d365ba16 14
ykuroda 0:13a5d365ba16 15 namespace Eigen {
ykuroda 0:13a5d365ba16 16
ykuroda 0:13a5d365ba16 17 /** \class Reverse
ykuroda 0:13a5d365ba16 18 * \ingroup Core_Module
ykuroda 0:13a5d365ba16 19 *
ykuroda 0:13a5d365ba16 20 * \brief Expression of the reverse of a vector or matrix
ykuroda 0:13a5d365ba16 21 *
ykuroda 0:13a5d365ba16 22 * \param MatrixType the type of the object of which we are taking the reverse
ykuroda 0:13a5d365ba16 23 *
ykuroda 0:13a5d365ba16 24 * This class represents an expression of the reverse of a vector.
ykuroda 0:13a5d365ba16 25 * It is the return type of MatrixBase::reverse() and VectorwiseOp::reverse()
ykuroda 0:13a5d365ba16 26 * and most of the time this is the only way it is used.
ykuroda 0:13a5d365ba16 27 *
ykuroda 0:13a5d365ba16 28 * \sa MatrixBase::reverse(), VectorwiseOp::reverse()
ykuroda 0:13a5d365ba16 29 */
ykuroda 0:13a5d365ba16 30
ykuroda 0:13a5d365ba16 31 namespace internal {
ykuroda 0:13a5d365ba16 32
ykuroda 0:13a5d365ba16 33 template<typename MatrixType, int Direction>
ykuroda 0:13a5d365ba16 34 struct traits<Reverse<MatrixType, Direction> >
ykuroda 0:13a5d365ba16 35 : traits<MatrixType>
ykuroda 0:13a5d365ba16 36 {
ykuroda 0:13a5d365ba16 37 typedef typename MatrixType::Scalar Scalar;
ykuroda 0:13a5d365ba16 38 typedef typename traits<MatrixType>::StorageKind StorageKind;
ykuroda 0:13a5d365ba16 39 typedef typename traits<MatrixType>::XprKind XprKind;
ykuroda 0:13a5d365ba16 40 typedef typename nested<MatrixType>::type MatrixTypeNested;
ykuroda 0:13a5d365ba16 41 typedef typename remove_reference<MatrixTypeNested>::type _MatrixTypeNested;
ykuroda 0:13a5d365ba16 42 enum {
ykuroda 0:13a5d365ba16 43 RowsAtCompileTime = MatrixType::RowsAtCompileTime,
ykuroda 0:13a5d365ba16 44 ColsAtCompileTime = MatrixType::ColsAtCompileTime,
ykuroda 0:13a5d365ba16 45 MaxRowsAtCompileTime = MatrixType::MaxRowsAtCompileTime,
ykuroda 0:13a5d365ba16 46 MaxColsAtCompileTime = MatrixType::MaxColsAtCompileTime,
ykuroda 0:13a5d365ba16 47
ykuroda 0:13a5d365ba16 48 // let's enable LinearAccess only with vectorization because of the product overhead
ykuroda 0:13a5d365ba16 49 LinearAccess = ( (Direction==BothDirections) && (int(_MatrixTypeNested::Flags)&PacketAccessBit) )
ykuroda 0:13a5d365ba16 50 ? LinearAccessBit : 0,
ykuroda 0:13a5d365ba16 51
ykuroda 0:13a5d365ba16 52 Flags = int(_MatrixTypeNested::Flags) & (HereditaryBits | LvalueBit | PacketAccessBit | LinearAccess),
ykuroda 0:13a5d365ba16 53
ykuroda 0:13a5d365ba16 54 CoeffReadCost = _MatrixTypeNested::CoeffReadCost
ykuroda 0:13a5d365ba16 55 };
ykuroda 0:13a5d365ba16 56 };
ykuroda 0:13a5d365ba16 57
ykuroda 0:13a5d365ba16 58 template<typename PacketScalar, bool ReversePacket> struct reverse_packet_cond
ykuroda 0:13a5d365ba16 59 {
ykuroda 0:13a5d365ba16 60 static inline PacketScalar run(const PacketScalar& x) { return preverse(x); }
ykuroda 0:13a5d365ba16 61 };
ykuroda 0:13a5d365ba16 62
ykuroda 0:13a5d365ba16 63 template<typename PacketScalar> struct reverse_packet_cond<PacketScalar,false>
ykuroda 0:13a5d365ba16 64 {
ykuroda 0:13a5d365ba16 65 static inline PacketScalar run(const PacketScalar& x) { return x; }
ykuroda 0:13a5d365ba16 66 };
ykuroda 0:13a5d365ba16 67
ykuroda 0:13a5d365ba16 68 } // end namespace internal
ykuroda 0:13a5d365ba16 69
ykuroda 0:13a5d365ba16 70 template<typename MatrixType, int Direction> class Reverse
ykuroda 0:13a5d365ba16 71 : public internal::dense_xpr_base< Reverse<MatrixType, Direction> >::type
ykuroda 0:13a5d365ba16 72 {
ykuroda 0:13a5d365ba16 73 public:
ykuroda 0:13a5d365ba16 74
ykuroda 0:13a5d365ba16 75 typedef typename internal::dense_xpr_base<Reverse>::type Base;
ykuroda 0:13a5d365ba16 76 EIGEN_DENSE_PUBLIC_INTERFACE(Reverse)
ykuroda 0:13a5d365ba16 77 using Base::IsRowMajor;
ykuroda 0:13a5d365ba16 78
ykuroda 0:13a5d365ba16 79 // next line is necessary because otherwise const version of operator()
ykuroda 0:13a5d365ba16 80 // is hidden by non-const version defined in this file
ykuroda 0:13a5d365ba16 81 using Base::operator();
ykuroda 0:13a5d365ba16 82
ykuroda 0:13a5d365ba16 83 protected:
ykuroda 0:13a5d365ba16 84 enum {
ykuroda 0:13a5d365ba16 85 PacketSize = internal::packet_traits<Scalar>::size,
ykuroda 0:13a5d365ba16 86 IsColMajor = !IsRowMajor,
ykuroda 0:13a5d365ba16 87 ReverseRow = (Direction == Vertical) || (Direction == BothDirections),
ykuroda 0:13a5d365ba16 88 ReverseCol = (Direction == Horizontal) || (Direction == BothDirections),
ykuroda 0:13a5d365ba16 89 OffsetRow = ReverseRow && IsColMajor ? PacketSize : 1,
ykuroda 0:13a5d365ba16 90 OffsetCol = ReverseCol && IsRowMajor ? PacketSize : 1,
ykuroda 0:13a5d365ba16 91 ReversePacket = (Direction == BothDirections)
ykuroda 0:13a5d365ba16 92 || ((Direction == Vertical) && IsColMajor)
ykuroda 0:13a5d365ba16 93 || ((Direction == Horizontal) && IsRowMajor)
ykuroda 0:13a5d365ba16 94 };
ykuroda 0:13a5d365ba16 95 typedef internal::reverse_packet_cond<PacketScalar,ReversePacket> reverse_packet;
ykuroda 0:13a5d365ba16 96 public:
ykuroda 0:13a5d365ba16 97
ykuroda 0:13a5d365ba16 98 inline Reverse(const MatrixType& matrix) : m_matrix(matrix) { }
ykuroda 0:13a5d365ba16 99
ykuroda 0:13a5d365ba16 100 EIGEN_INHERIT_ASSIGNMENT_OPERATORS(Reverse)
ykuroda 0:13a5d365ba16 101
ykuroda 0:13a5d365ba16 102 inline Index rows() const { return m_matrix.rows(); }
ykuroda 0:13a5d365ba16 103 inline Index cols() const { return m_matrix.cols(); }
ykuroda 0:13a5d365ba16 104
ykuroda 0:13a5d365ba16 105 inline Index innerStride() const
ykuroda 0:13a5d365ba16 106 {
ykuroda 0:13a5d365ba16 107 return -m_matrix.innerStride();
ykuroda 0:13a5d365ba16 108 }
ykuroda 0:13a5d365ba16 109
ykuroda 0:13a5d365ba16 110 inline Scalar& operator()(Index row, Index col)
ykuroda 0:13a5d365ba16 111 {
ykuroda 0:13a5d365ba16 112 eigen_assert(row >= 0 && row < rows() && col >= 0 && col < cols());
ykuroda 0:13a5d365ba16 113 return coeffRef(row, col);
ykuroda 0:13a5d365ba16 114 }
ykuroda 0:13a5d365ba16 115
ykuroda 0:13a5d365ba16 116 inline Scalar& coeffRef(Index row, Index col)
ykuroda 0:13a5d365ba16 117 {
ykuroda 0:13a5d365ba16 118 return m_matrix.const_cast_derived().coeffRef(ReverseRow ? m_matrix.rows() - row - 1 : row,
ykuroda 0:13a5d365ba16 119 ReverseCol ? m_matrix.cols() - col - 1 : col);
ykuroda 0:13a5d365ba16 120 }
ykuroda 0:13a5d365ba16 121
ykuroda 0:13a5d365ba16 122 inline CoeffReturnType coeff(Index row, Index col) const
ykuroda 0:13a5d365ba16 123 {
ykuroda 0:13a5d365ba16 124 return m_matrix.coeff(ReverseRow ? m_matrix.rows() - row - 1 : row,
ykuroda 0:13a5d365ba16 125 ReverseCol ? m_matrix.cols() - col - 1 : col);
ykuroda 0:13a5d365ba16 126 }
ykuroda 0:13a5d365ba16 127
ykuroda 0:13a5d365ba16 128 inline CoeffReturnType coeff(Index index) const
ykuroda 0:13a5d365ba16 129 {
ykuroda 0:13a5d365ba16 130 return m_matrix.coeff(m_matrix.size() - index - 1);
ykuroda 0:13a5d365ba16 131 }
ykuroda 0:13a5d365ba16 132
ykuroda 0:13a5d365ba16 133 inline Scalar& coeffRef(Index index)
ykuroda 0:13a5d365ba16 134 {
ykuroda 0:13a5d365ba16 135 return m_matrix.const_cast_derived().coeffRef(m_matrix.size() - index - 1);
ykuroda 0:13a5d365ba16 136 }
ykuroda 0:13a5d365ba16 137
ykuroda 0:13a5d365ba16 138 inline Scalar& operator()(Index index)
ykuroda 0:13a5d365ba16 139 {
ykuroda 0:13a5d365ba16 140 eigen_assert(index >= 0 && index < m_matrix.size());
ykuroda 0:13a5d365ba16 141 return coeffRef(index);
ykuroda 0:13a5d365ba16 142 }
ykuroda 0:13a5d365ba16 143
ykuroda 0:13a5d365ba16 144 template<int LoadMode>
ykuroda 0:13a5d365ba16 145 inline const PacketScalar packet(Index row, Index col) const
ykuroda 0:13a5d365ba16 146 {
ykuroda 0:13a5d365ba16 147 return reverse_packet::run(m_matrix.template packet<LoadMode>(
ykuroda 0:13a5d365ba16 148 ReverseRow ? m_matrix.rows() - row - OffsetRow : row,
ykuroda 0:13a5d365ba16 149 ReverseCol ? m_matrix.cols() - col - OffsetCol : col));
ykuroda 0:13a5d365ba16 150 }
ykuroda 0:13a5d365ba16 151
ykuroda 0:13a5d365ba16 152 template<int LoadMode>
ykuroda 0:13a5d365ba16 153 inline void writePacket(Index row, Index col, const PacketScalar& x)
ykuroda 0:13a5d365ba16 154 {
ykuroda 0:13a5d365ba16 155 m_matrix.const_cast_derived().template writePacket<LoadMode>(
ykuroda 0:13a5d365ba16 156 ReverseRow ? m_matrix.rows() - row - OffsetRow : row,
ykuroda 0:13a5d365ba16 157 ReverseCol ? m_matrix.cols() - col - OffsetCol : col,
ykuroda 0:13a5d365ba16 158 reverse_packet::run(x));
ykuroda 0:13a5d365ba16 159 }
ykuroda 0:13a5d365ba16 160
ykuroda 0:13a5d365ba16 161 template<int LoadMode>
ykuroda 0:13a5d365ba16 162 inline const PacketScalar packet(Index index) const
ykuroda 0:13a5d365ba16 163 {
ykuroda 0:13a5d365ba16 164 return internal::preverse(m_matrix.template packet<LoadMode>( m_matrix.size() - index - PacketSize ));
ykuroda 0:13a5d365ba16 165 }
ykuroda 0:13a5d365ba16 166
ykuroda 0:13a5d365ba16 167 template<int LoadMode>
ykuroda 0:13a5d365ba16 168 inline void writePacket(Index index, const PacketScalar& x)
ykuroda 0:13a5d365ba16 169 {
ykuroda 0:13a5d365ba16 170 m_matrix.const_cast_derived().template writePacket<LoadMode>(m_matrix.size() - index - PacketSize, internal::preverse(x));
ykuroda 0:13a5d365ba16 171 }
ykuroda 0:13a5d365ba16 172
ykuroda 0:13a5d365ba16 173 const typename internal::remove_all<typename MatrixType::Nested>::type&
ykuroda 0:13a5d365ba16 174 nestedExpression() const
ykuroda 0:13a5d365ba16 175 {
ykuroda 0:13a5d365ba16 176 return m_matrix;
ykuroda 0:13a5d365ba16 177 }
ykuroda 0:13a5d365ba16 178
ykuroda 0:13a5d365ba16 179 protected:
ykuroda 0:13a5d365ba16 180 typename MatrixType::Nested m_matrix;
ykuroda 0:13a5d365ba16 181 };
ykuroda 0:13a5d365ba16 182
ykuroda 0:13a5d365ba16 183 /** \returns an expression of the reverse of *this.
ykuroda 0:13a5d365ba16 184 *
ykuroda 0:13a5d365ba16 185 * Example: \include MatrixBase_reverse.cpp
ykuroda 0:13a5d365ba16 186 * Output: \verbinclude MatrixBase_reverse.out
ykuroda 0:13a5d365ba16 187 *
ykuroda 0:13a5d365ba16 188 */
ykuroda 0:13a5d365ba16 189 template<typename Derived>
ykuroda 0:13a5d365ba16 190 inline typename DenseBase<Derived>::ReverseReturnType
ykuroda 0:13a5d365ba16 191 DenseBase<Derived>::reverse()
ykuroda 0:13a5d365ba16 192 {
ykuroda 0:13a5d365ba16 193 return derived();
ykuroda 0:13a5d365ba16 194 }
ykuroda 0:13a5d365ba16 195
ykuroda 0:13a5d365ba16 196 /** This is the const version of reverse(). */
ykuroda 0:13a5d365ba16 197 template<typename Derived>
ykuroda 0:13a5d365ba16 198 inline const typename DenseBase<Derived>::ConstReverseReturnType
ykuroda 0:13a5d365ba16 199 DenseBase<Derived>::reverse() const
ykuroda 0:13a5d365ba16 200 {
ykuroda 0:13a5d365ba16 201 return derived();
ykuroda 0:13a5d365ba16 202 }
ykuroda 0:13a5d365ba16 203
ykuroda 0:13a5d365ba16 204 /** This is the "in place" version of reverse: it reverses \c *this.
ykuroda 0:13a5d365ba16 205 *
ykuroda 0:13a5d365ba16 206 * In most cases it is probably better to simply use the reversed expression
ykuroda 0:13a5d365ba16 207 * of a matrix. However, when reversing the matrix data itself is really needed,
ykuroda 0:13a5d365ba16 208 * then this "in-place" version is probably the right choice because it provides
ykuroda 0:13a5d365ba16 209 * the following additional features:
ykuroda 0:13a5d365ba16 210 * - less error prone: doing the same operation with .reverse() requires special care:
ykuroda 0:13a5d365ba16 211 * \code m = m.reverse().eval(); \endcode
ykuroda 0:13a5d365ba16 212 * - this API allows to avoid creating a temporary (the current implementation creates a temporary, but that could be avoided using swap)
ykuroda 0:13a5d365ba16 213 * - it allows future optimizations (cache friendliness, etc.)
ykuroda 0:13a5d365ba16 214 *
ykuroda 0:13a5d365ba16 215 * \sa reverse() */
ykuroda 0:13a5d365ba16 216 template<typename Derived>
ykuroda 0:13a5d365ba16 217 inline void DenseBase<Derived>::reverseInPlace()
ykuroda 0:13a5d365ba16 218 {
ykuroda 0:13a5d365ba16 219 derived() = derived().reverse().eval();
ykuroda 0:13a5d365ba16 220 }
ykuroda 0:13a5d365ba16 221
ykuroda 0:13a5d365ba16 222 } // end namespace Eigen
ykuroda 0:13a5d365ba16 223
ykuroda 0:13a5d365ba16 224 #endif // EIGEN_REVERSE_H