1// This file is part of Eigen, a lightweight C++ template library
2// for linear algebra.
3//
4// Copyright (C) 2006-2008 Benoit Jacob <jacob.benoit.1@gmail.com>
5// Copyright (C) 2009-2014 Gael Guennebaud <gael.guennebaud@inria.fr>
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_TRANSPOSE_H
12#define EIGEN_TRANSPOSE_H
13
14namespace Eigen {
15
16namespace internal {
17template<typename MatrixType>
18struct traits<Transpose<MatrixType> > : public traits<MatrixType>
19{
20 typedef typename ref_selector<MatrixType>::type MatrixTypeNested;
21 typedef typename remove_reference<MatrixTypeNested>::type MatrixTypeNestedPlain;
22 enum {
23 RowsAtCompileTime = MatrixType::ColsAtCompileTime,
24 ColsAtCompileTime = MatrixType::RowsAtCompileTime,
25 MaxRowsAtCompileTime = MatrixType::MaxColsAtCompileTime,
26 MaxColsAtCompileTime = MatrixType::MaxRowsAtCompileTime,
27 FlagsLvalueBit = is_lvalue<MatrixType>::value ? LvalueBit : 0,
28 Flags0 = traits<MatrixTypeNestedPlain>::Flags & ~(LvalueBit | NestByRefBit),
29 Flags1 = Flags0 | FlagsLvalueBit,
30 Flags = Flags1 ^ RowMajorBit,
31 InnerStrideAtCompileTime = inner_stride_at_compile_time<MatrixType>::ret,
32 OuterStrideAtCompileTime = outer_stride_at_compile_time<MatrixType>::ret
33 };
34};
35}
36
37template<typename MatrixType, typename StorageKind> class TransposeImpl;
38
39/** \class Transpose
40 * \ingroup Core_Module
41 *
42 * \brief Expression of the transpose of a matrix
43 *
44 * \tparam MatrixType the type of the object of which we are taking the transpose
45 *
46 * This class represents an expression of the transpose of a matrix.
47 * It is the return type of MatrixBase::transpose() and MatrixBase::adjoint()
48 * and most of the time this is the only way it is used.
49 *
50 * \sa MatrixBase::transpose(), MatrixBase::adjoint()
51 */
52template<typename MatrixType> class Transpose
53 : public TransposeImpl<MatrixType,typename internal::traits<MatrixType>::StorageKind>
54{
55 public:
56
57 typedef typename internal::ref_selector<MatrixType>::non_const_type MatrixTypeNested;
58
59 typedef typename TransposeImpl<MatrixType,typename internal::traits<MatrixType>::StorageKind>::Base Base;
60 EIGEN_GENERIC_PUBLIC_INTERFACE(Transpose)
61 typedef typename internal::remove_all<MatrixType>::type NestedExpression;
62
63 EIGEN_DEVICE_FUNC
64 explicit inline Transpose(MatrixType& matrix) : m_matrix(matrix) {}
65
66 EIGEN_INHERIT_ASSIGNMENT_OPERATORS(Transpose)
67
68 EIGEN_DEVICE_FUNC inline Index rows() const { return m_matrix.cols(); }
69 EIGEN_DEVICE_FUNC inline Index cols() const { return m_matrix.rows(); }
70
71 /** \returns the nested expression */
72 EIGEN_DEVICE_FUNC
73 const typename internal::remove_all<MatrixTypeNested>::type&
74 nestedExpression() const { return m_matrix; }
75
76 /** \returns the nested expression */
77 EIGEN_DEVICE_FUNC
78 typename internal::remove_reference<MatrixTypeNested>::type&
79 nestedExpression() { return m_matrix; }
80
81 /** \internal */
82 void resize(Index nrows, Index ncols) {
83 m_matrix.resize(ncols,nrows);
84 }
85
86 protected:
87 typename internal::ref_selector<MatrixType>::non_const_type m_matrix;
88};
89
90namespace internal {
91
92template<typename MatrixType, bool HasDirectAccess = has_direct_access<MatrixType>::ret>
93struct TransposeImpl_base
94{
95 typedef typename dense_xpr_base<Transpose<MatrixType> >::type type;
96};
97
98template<typename MatrixType>
99struct TransposeImpl_base<MatrixType, false>
100{
101 typedef typename dense_xpr_base<Transpose<MatrixType> >::type type;
102};
103
104} // end namespace internal
105
106// Generic API dispatcher
107template<typename XprType, typename StorageKind>
108class TransposeImpl
109 : public internal::generic_xpr_base<Transpose<XprType> >::type
110{
111public:
112 typedef typename internal::generic_xpr_base<Transpose<XprType> >::type Base;
113};
114
115template<typename MatrixType> class TransposeImpl<MatrixType,Dense>
116 : public internal::TransposeImpl_base<MatrixType>::type
117{
118 public:
119
120 typedef typename internal::TransposeImpl_base<MatrixType>::type Base;
121 using Base::coeffRef;
122 EIGEN_DENSE_PUBLIC_INTERFACE(Transpose<MatrixType>)
123 EIGEN_INHERIT_ASSIGNMENT_OPERATORS(TransposeImpl)
124
125 EIGEN_DEVICE_FUNC inline Index innerStride() const { return derived().nestedExpression().innerStride(); }
126 EIGEN_DEVICE_FUNC inline Index outerStride() const { return derived().nestedExpression().outerStride(); }
127
128 typedef typename internal::conditional<
129 internal::is_lvalue<MatrixType>::value,
130 Scalar,
131 const Scalar
132 >::type ScalarWithConstIfNotLvalue;
133
134 EIGEN_DEVICE_FUNC inline ScalarWithConstIfNotLvalue* data() { return derived().nestedExpression().data(); }
135 EIGEN_DEVICE_FUNC inline const Scalar* data() const { return derived().nestedExpression().data(); }
136
137 // FIXME: shall we keep the const version of coeffRef?
138 EIGEN_DEVICE_FUNC
139 inline const Scalar& coeffRef(Index rowId, Index colId) const
140 {
141 return derived().nestedExpression().coeffRef(colId, rowId);
142 }
143
144 EIGEN_DEVICE_FUNC
145 inline const Scalar& coeffRef(Index index) const
146 {
147 return derived().nestedExpression().coeffRef(index);
148 }
149};
150
151/** \returns an expression of the transpose of *this.
152 *
153 * Example: \include MatrixBase_transpose.cpp
154 * Output: \verbinclude MatrixBase_transpose.out
155 *
156 * \warning If you want to replace a matrix by its own transpose, do \b NOT do this:
157 * \code
158 * m = m.transpose(); // bug!!! caused by aliasing effect
159 * \endcode
160 * Instead, use the transposeInPlace() method:
161 * \code
162 * m.transposeInPlace();
163 * \endcode
164 * which gives Eigen good opportunities for optimization, or alternatively you can also do:
165 * \code
166 * m = m.transpose().eval();
167 * \endcode
168 *
169 * \sa transposeInPlace(), adjoint() */
170template<typename Derived>
171inline Transpose<Derived>
172DenseBase<Derived>::transpose()
173{
174 return TransposeReturnType(derived());
175}
176
177/** This is the const version of transpose().
178 *
179 * Make sure you read the warning for transpose() !
180 *
181 * \sa transposeInPlace(), adjoint() */
182template<typename Derived>
183inline typename DenseBase<Derived>::ConstTransposeReturnType
184DenseBase<Derived>::transpose() const
185{
186 return ConstTransposeReturnType(derived());
187}
188
189/** \returns an expression of the adjoint (i.e. conjugate transpose) of *this.
190 *
191 * Example: \include MatrixBase_adjoint.cpp
192 * Output: \verbinclude MatrixBase_adjoint.out
193 *
194 * \warning If you want to replace a matrix by its own adjoint, do \b NOT do this:
195 * \code
196 * m = m.adjoint(); // bug!!! caused by aliasing effect
197 * \endcode
198 * Instead, use the adjointInPlace() method:
199 * \code
200 * m.adjointInPlace();
201 * \endcode
202 * which gives Eigen good opportunities for optimization, or alternatively you can also do:
203 * \code
204 * m = m.adjoint().eval();
205 * \endcode
206 *
207 * \sa adjointInPlace(), transpose(), conjugate(), class Transpose, class internal::scalar_conjugate_op */
208template<typename Derived>
209inline const typename MatrixBase<Derived>::AdjointReturnType
210MatrixBase<Derived>::adjoint() const
211{
212 return AdjointReturnType(this->transpose());
213}
214
215/***************************************************************************
216* "in place" transpose implementation
217***************************************************************************/
218
219namespace internal {
220
221template<typename MatrixType,
222 bool IsSquare = (MatrixType::RowsAtCompileTime == MatrixType::ColsAtCompileTime) && MatrixType::RowsAtCompileTime!=Dynamic,
223 bool MatchPacketSize =
224 (int(MatrixType::RowsAtCompileTime) == int(internal::packet_traits<typename MatrixType::Scalar>::size))
225 && (internal::evaluator<MatrixType>::Flags&PacketAccessBit) >
226struct inplace_transpose_selector;
227
228template<typename MatrixType>
229struct inplace_transpose_selector<MatrixType,true,false> { // square matrix
230 static void run(MatrixType& m) {
231 m.matrix().template triangularView<StrictlyUpper>().swap(m.matrix().transpose());
232 }
233};
234
235// TODO: vectorized path is currently limited to LargestPacketSize x LargestPacketSize cases only.
236template<typename MatrixType>
237struct inplace_transpose_selector<MatrixType,true,true> { // PacketSize x PacketSize
238 static void run(MatrixType& m) {
239 typedef typename MatrixType::Scalar Scalar;
240 typedef typename internal::packet_traits<typename MatrixType::Scalar>::type Packet;
241 const Index PacketSize = internal::packet_traits<Scalar>::size;
242 const Index Alignment = internal::evaluator<MatrixType>::Alignment;
243 PacketBlock<Packet> A;
244 for (Index i=0; i<PacketSize; ++i)
245 A.packet[i] = m.template packetByOuterInner<Alignment>(i,0);
246 internal::ptranspose(A);
247 for (Index i=0; i<PacketSize; ++i)
248 m.template writePacket<Alignment>(m.rowIndexByOuterInner(i,0), m.colIndexByOuterInner(i,0), A.packet[i]);
249 }
250};
251
252template<typename MatrixType,bool MatchPacketSize>
253struct inplace_transpose_selector<MatrixType,false,MatchPacketSize> { // non square matrix
254 static void run(MatrixType& m) {
255 if (m.rows()==m.cols())
256 m.matrix().template triangularView<StrictlyUpper>().swap(m.matrix().transpose());
257 else
258 m = m.transpose().eval();
259 }
260};
261
262} // end namespace internal
263
264/** This is the "in place" version of transpose(): it replaces \c *this by its own transpose.
265 * Thus, doing
266 * \code
267 * m.transposeInPlace();
268 * \endcode
269 * has the same effect on m as doing
270 * \code
271 * m = m.transpose().eval();
272 * \endcode
273 * and is faster and also safer because in the latter line of code, forgetting the eval() results
274 * in a bug caused by \ref TopicAliasing "aliasing".
275 *
276 * Notice however that this method is only useful if you want to replace a matrix by its own transpose.
277 * If you just need the transpose of a matrix, use transpose().
278 *
279 * \note if the matrix is not square, then \c *this must be a resizable matrix.
280 * This excludes (non-square) fixed-size matrices, block-expressions and maps.
281 *
282 * \sa transpose(), adjoint(), adjointInPlace() */
283template<typename Derived>
284inline void DenseBase<Derived>::transposeInPlace()
285{
286 eigen_assert((rows() == cols() || (RowsAtCompileTime == Dynamic && ColsAtCompileTime == Dynamic))
287 && "transposeInPlace() called on a non-square non-resizable matrix");
288 internal::inplace_transpose_selector<Derived>::run(derived());
289}
290
291/***************************************************************************
292* "in place" adjoint implementation
293***************************************************************************/
294
295/** This is the "in place" version of adjoint(): it replaces \c *this by its own transpose.
296 * Thus, doing
297 * \code
298 * m.adjointInPlace();
299 * \endcode
300 * has the same effect on m as doing
301 * \code
302 * m = m.adjoint().eval();
303 * \endcode
304 * and is faster and also safer because in the latter line of code, forgetting the eval() results
305 * in a bug caused by aliasing.
306 *
307 * Notice however that this method is only useful if you want to replace a matrix by its own adjoint.
308 * If you just need the adjoint of a matrix, use adjoint().
309 *
310 * \note if the matrix is not square, then \c *this must be a resizable matrix.
311 * This excludes (non-square) fixed-size matrices, block-expressions and maps.
312 *
313 * \sa transpose(), adjoint(), transposeInPlace() */
314template<typename Derived>
315inline void MatrixBase<Derived>::adjointInPlace()
316{
317 derived() = adjoint().eval();
318}
319
320#ifndef EIGEN_NO_DEBUG
321
322// The following is to detect aliasing problems in most common cases.
323
324namespace internal {
325
326template<bool DestIsTransposed, typename OtherDerived>
327struct check_transpose_aliasing_compile_time_selector
328{
329 enum { ret = bool(blas_traits<OtherDerived>::IsTransposed) != DestIsTransposed };
330};
331
332template<bool DestIsTransposed, typename BinOp, typename DerivedA, typename DerivedB>
333struct check_transpose_aliasing_compile_time_selector<DestIsTransposed,CwiseBinaryOp<BinOp,DerivedA,DerivedB> >
334{
335 enum { ret = bool(blas_traits<DerivedA>::IsTransposed) != DestIsTransposed
336 || bool(blas_traits<DerivedB>::IsTransposed) != DestIsTransposed
337 };
338};
339
340template<typename Scalar, bool DestIsTransposed, typename OtherDerived>
341struct check_transpose_aliasing_run_time_selector
342{
343 static bool run(const Scalar* dest, const OtherDerived& src)
344 {
345 return (bool(blas_traits<OtherDerived>::IsTransposed) != DestIsTransposed) && (dest!=0 && dest==(const Scalar*)extract_data(src));
346 }
347};
348
349template<typename Scalar, bool DestIsTransposed, typename BinOp, typename DerivedA, typename DerivedB>
350struct check_transpose_aliasing_run_time_selector<Scalar,DestIsTransposed,CwiseBinaryOp<BinOp,DerivedA,DerivedB> >
351{
352 static bool run(const Scalar* dest, const CwiseBinaryOp<BinOp,DerivedA,DerivedB>& src)
353 {
354 return ((blas_traits<DerivedA>::IsTransposed != DestIsTransposed) && (dest!=0 && dest==(const Scalar*)extract_data(src.lhs())))
355 || ((blas_traits<DerivedB>::IsTransposed != DestIsTransposed) && (dest!=0 && dest==(const Scalar*)extract_data(src.rhs())));
356 }
357};
358
359// the following selector, checkTransposeAliasing_impl, based on MightHaveTransposeAliasing,
360// is because when the condition controlling the assert is known at compile time, ICC emits a warning.
361// This is actually a good warning: in expressions that don't have any transposing, the condition is
362// known at compile time to be false, and using that, we can avoid generating the code of the assert again
363// and again for all these expressions that don't need it.
364
365template<typename Derived, typename OtherDerived,
366 bool MightHaveTransposeAliasing
367 = check_transpose_aliasing_compile_time_selector
368 <blas_traits<Derived>::IsTransposed,OtherDerived>::ret
369 >
370struct checkTransposeAliasing_impl
371{
372 static void run(const Derived& dst, const OtherDerived& other)
373 {
374 eigen_assert((!check_transpose_aliasing_run_time_selector
375 <typename Derived::Scalar,blas_traits<Derived>::IsTransposed,OtherDerived>
376 ::run(extract_data(dst), other))
377 && "aliasing detected during transposition, use transposeInPlace() "
378 "or evaluate the rhs into a temporary using .eval()");
379
380 }
381};
382
383template<typename Derived, typename OtherDerived>
384struct checkTransposeAliasing_impl<Derived, OtherDerived, false>
385{
386 static void run(const Derived&, const OtherDerived&)
387 {
388 }
389};
390
391template<typename Dst, typename Src>
392void check_for_aliasing(const Dst &dst, const Src &src)
393{
394 internal::checkTransposeAliasing_impl<Dst, Src>::run(dst, src);
395}
396
397} // end namespace internal
398
399#endif // EIGEN_NO_DEBUG
400
401} // end namespace Eigen
402
403#endif // EIGEN_TRANSPOSE_H
404