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 (at) gmail.com> 5 // Copyright (C) 2009-2010 Gael Guennebaud <gael.guennebaud (at) 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 14 namespace Eigen { 15 16 /** \class Transpose 17 * \ingroup Core_Module 18 * 19 * \brief Expression of the transpose of a matrix 20 * 21 * \param MatrixType the type of the object of which we are taking the transpose 22 * 23 * This class represents an expression of the transpose of a matrix. 24 * It is the return type of MatrixBase::transpose() and MatrixBase::adjoint() 25 * and most of the time this is the only way it is used. 26 * 27 * \sa MatrixBase::transpose(), MatrixBase::adjoint() 28 */ 29 30 namespace internal { 31 template<typename MatrixType> 32 struct traits<Transpose<MatrixType> > : traits<MatrixType> 33 { 34 typedef typename MatrixType::Scalar Scalar; 35 typedef typename nested<MatrixType>::type MatrixTypeNested; 36 typedef typename remove_reference<MatrixTypeNested>::type MatrixTypeNestedPlain; 37 typedef typename traits<MatrixType>::StorageKind StorageKind; 38 typedef typename traits<MatrixType>::XprKind XprKind; 39 enum { 40 RowsAtCompileTime = MatrixType::ColsAtCompileTime, 41 ColsAtCompileTime = MatrixType::RowsAtCompileTime, 42 MaxRowsAtCompileTime = MatrixType::MaxColsAtCompileTime, 43 MaxColsAtCompileTime = MatrixType::MaxRowsAtCompileTime, 44 FlagsLvalueBit = is_lvalue<MatrixType>::value ? LvalueBit : 0, 45 Flags0 = MatrixTypeNestedPlain::Flags & ~(LvalueBit | NestByRefBit), 46 Flags1 = Flags0 | FlagsLvalueBit, 47 Flags = Flags1 ^ RowMajorBit, 48 CoeffReadCost = MatrixTypeNestedPlain::CoeffReadCost, 49 InnerStrideAtCompileTime = inner_stride_at_compile_time<MatrixType>::ret, 50 OuterStrideAtCompileTime = outer_stride_at_compile_time<MatrixType>::ret 51 }; 52 }; 53 } 54 55 template<typename MatrixType, typename StorageKind> class TransposeImpl; 56 57 template<typename MatrixType> class Transpose 58 : public TransposeImpl<MatrixType,typename internal::traits<MatrixType>::StorageKind> 59 { 60 public: 61 62 typedef typename TransposeImpl<MatrixType,typename internal::traits<MatrixType>::StorageKind>::Base Base; 63 EIGEN_GENERIC_PUBLIC_INTERFACE(Transpose) 64 65 inline Transpose(MatrixType& matrix) : m_matrix(matrix) {} 66 67 EIGEN_INHERIT_ASSIGNMENT_OPERATORS(Transpose) 68 69 inline Index rows() const { return m_matrix.cols(); } 70 inline Index cols() const { return m_matrix.rows(); } 71 72 /** \returns the nested expression */ 73 const typename internal::remove_all<typename MatrixType::Nested>::type& 74 nestedExpression() const { return m_matrix; } 75 76 /** \returns the nested expression */ 77 typename internal::remove_all<typename MatrixType::Nested>::type& 78 nestedExpression() { return m_matrix.const_cast_derived(); } 79 80 protected: 81 typename MatrixType::Nested m_matrix; 82 }; 83 84 namespace internal { 85 86 template<typename MatrixType, bool HasDirectAccess = has_direct_access<MatrixType>::ret> 87 struct TransposeImpl_base 88 { 89 typedef typename dense_xpr_base<Transpose<MatrixType> >::type type; 90 }; 91 92 template<typename MatrixType> 93 struct TransposeImpl_base<MatrixType, false> 94 { 95 typedef typename dense_xpr_base<Transpose<MatrixType> >::type type; 96 }; 97 98 } // end namespace internal 99 100 template<typename MatrixType> class TransposeImpl<MatrixType,Dense> 101 : public internal::TransposeImpl_base<MatrixType>::type 102 { 103 public: 104 105 typedef typename internal::TransposeImpl_base<MatrixType>::type Base; 106 EIGEN_DENSE_PUBLIC_INTERFACE(Transpose<MatrixType>) 107 108 inline Index innerStride() const { return derived().nestedExpression().innerStride(); } 109 inline Index outerStride() const { return derived().nestedExpression().outerStride(); } 110 111 typedef typename internal::conditional< 112 internal::is_lvalue<MatrixType>::value, 113 Scalar, 114 const Scalar 115 >::type ScalarWithConstIfNotLvalue; 116 117 inline ScalarWithConstIfNotLvalue* data() { return derived().nestedExpression().data(); } 118 inline const Scalar* data() const { return derived().nestedExpression().data(); } 119 120 inline ScalarWithConstIfNotLvalue& coeffRef(Index row, Index col) 121 { 122 EIGEN_STATIC_ASSERT_LVALUE(MatrixType) 123 return derived().nestedExpression().const_cast_derived().coeffRef(col, row); 124 } 125 126 inline ScalarWithConstIfNotLvalue& coeffRef(Index index) 127 { 128 EIGEN_STATIC_ASSERT_LVALUE(MatrixType) 129 return derived().nestedExpression().const_cast_derived().coeffRef(index); 130 } 131 132 inline const Scalar& coeffRef(Index row, Index col) const 133 { 134 return derived().nestedExpression().coeffRef(col, row); 135 } 136 137 inline const Scalar& coeffRef(Index index) const 138 { 139 return derived().nestedExpression().coeffRef(index); 140 } 141 142 inline CoeffReturnType coeff(Index row, Index col) const 143 { 144 return derived().nestedExpression().coeff(col, row); 145 } 146 147 inline CoeffReturnType coeff(Index index) const 148 { 149 return derived().nestedExpression().coeff(index); 150 } 151 152 template<int LoadMode> 153 inline const PacketScalar packet(Index row, Index col) const 154 { 155 return derived().nestedExpression().template packet<LoadMode>(col, row); 156 } 157 158 template<int LoadMode> 159 inline void writePacket(Index row, Index col, const PacketScalar& x) 160 { 161 derived().nestedExpression().const_cast_derived().template writePacket<LoadMode>(col, row, x); 162 } 163 164 template<int LoadMode> 165 inline const PacketScalar packet(Index index) const 166 { 167 return derived().nestedExpression().template packet<LoadMode>(index); 168 } 169 170 template<int LoadMode> 171 inline void writePacket(Index index, const PacketScalar& x) 172 { 173 derived().nestedExpression().const_cast_derived().template writePacket<LoadMode>(index, x); 174 } 175 }; 176 177 /** \returns an expression of the transpose of *this. 178 * 179 * Example: \include MatrixBase_transpose.cpp 180 * Output: \verbinclude MatrixBase_transpose.out 181 * 182 * \warning If you want to replace a matrix by its own transpose, do \b NOT do this: 183 * \code 184 * m = m.transpose(); // bug!!! caused by aliasing effect 185 * \endcode 186 * Instead, use the transposeInPlace() method: 187 * \code 188 * m.transposeInPlace(); 189 * \endcode 190 * which gives Eigen good opportunities for optimization, or alternatively you can also do: 191 * \code 192 * m = m.transpose().eval(); 193 * \endcode 194 * 195 * \sa transposeInPlace(), adjoint() */ 196 template<typename Derived> 197 inline Transpose<Derived> 198 DenseBase<Derived>::transpose() 199 { 200 return derived(); 201 } 202 203 /** This is the const version of transpose(). 204 * 205 * Make sure you read the warning for transpose() ! 206 * 207 * \sa transposeInPlace(), adjoint() */ 208 template<typename Derived> 209 inline const typename DenseBase<Derived>::ConstTransposeReturnType 210 DenseBase<Derived>::transpose() const 211 { 212 return ConstTransposeReturnType(derived()); 213 } 214 215 /** \returns an expression of the adjoint (i.e. conjugate transpose) of *this. 216 * 217 * Example: \include MatrixBase_adjoint.cpp 218 * Output: \verbinclude MatrixBase_adjoint.out 219 * 220 * \warning If you want to replace a matrix by its own adjoint, do \b NOT do this: 221 * \code 222 * m = m.adjoint(); // bug!!! caused by aliasing effect 223 * \endcode 224 * Instead, use the adjointInPlace() method: 225 * \code 226 * m.adjointInPlace(); 227 * \endcode 228 * which gives Eigen good opportunities for optimization, or alternatively you can also do: 229 * \code 230 * m = m.adjoint().eval(); 231 * \endcode 232 * 233 * \sa adjointInPlace(), transpose(), conjugate(), class Transpose, class internal::scalar_conjugate_op */ 234 template<typename Derived> 235 inline const typename MatrixBase<Derived>::AdjointReturnType 236 MatrixBase<Derived>::adjoint() const 237 { 238 return this->transpose(); // in the complex case, the .conjugate() is be implicit here 239 // due to implicit conversion to return type 240 } 241 242 /*************************************************************************** 243 * "in place" transpose implementation 244 ***************************************************************************/ 245 246 namespace internal { 247 248 template<typename MatrixType, 249 bool IsSquare = (MatrixType::RowsAtCompileTime == MatrixType::ColsAtCompileTime) && MatrixType::RowsAtCompileTime!=Dynamic> 250 struct inplace_transpose_selector; 251 252 template<typename MatrixType> 253 struct inplace_transpose_selector<MatrixType,true> { // square matrix 254 static void run(MatrixType& m) { 255 m.template triangularView<StrictlyUpper>().swap(m.transpose()); 256 } 257 }; 258 259 template<typename MatrixType> 260 struct inplace_transpose_selector<MatrixType,false> { // non square matrix 261 static void run(MatrixType& m) { 262 if (m.rows()==m.cols()) 263 m.template triangularView<StrictlyUpper>().swap(m.transpose()); 264 else 265 m = m.transpose().eval(); 266 } 267 }; 268 269 } // end namespace internal 270 271 /** This is the "in place" version of transpose(): it replaces \c *this by its own transpose. 272 * Thus, doing 273 * \code 274 * m.transposeInPlace(); 275 * \endcode 276 * has the same effect on m as doing 277 * \code 278 * m = m.transpose().eval(); 279 * \endcode 280 * and is faster and also safer because in the latter line of code, forgetting the eval() results 281 * in a bug caused by aliasing. 282 * 283 * Notice however that this method is only useful if you want to replace a matrix by its own transpose. 284 * If you just need the transpose of a matrix, use transpose(). 285 * 286 * \note if the matrix is not square, then \c *this must be a resizable matrix. 287 * 288 * \sa transpose(), adjoint(), adjointInPlace() */ 289 template<typename Derived> 290 inline void DenseBase<Derived>::transposeInPlace() 291 { 292 internal::inplace_transpose_selector<Derived>::run(derived()); 293 } 294 295 /*************************************************************************** 296 * "in place" adjoint implementation 297 ***************************************************************************/ 298 299 /** This is the "in place" version of adjoint(): it replaces \c *this by its own transpose. 300 * Thus, doing 301 * \code 302 * m.adjointInPlace(); 303 * \endcode 304 * has the same effect on m as doing 305 * \code 306 * m = m.adjoint().eval(); 307 * \endcode 308 * and is faster and also safer because in the latter line of code, forgetting the eval() results 309 * in a bug caused by aliasing. 310 * 311 * Notice however that this method is only useful if you want to replace a matrix by its own adjoint. 312 * If you just need the adjoint of a matrix, use adjoint(). 313 * 314 * \note if the matrix is not square, then \c *this must be a resizable matrix. 315 * 316 * \sa transpose(), adjoint(), transposeInPlace() */ 317 template<typename Derived> 318 inline void MatrixBase<Derived>::adjointInPlace() 319 { 320 derived() = adjoint().eval(); 321 } 322 323 #ifndef EIGEN_NO_DEBUG 324 325 // The following is to detect aliasing problems in most common cases. 326 327 namespace internal { 328 329 template<typename BinOp,typename NestedXpr,typename Rhs> 330 struct blas_traits<SelfCwiseBinaryOp<BinOp,NestedXpr,Rhs> > 331 : blas_traits<NestedXpr> 332 { 333 typedef SelfCwiseBinaryOp<BinOp,NestedXpr,Rhs> XprType; 334 static inline const XprType extract(const XprType& x) { return x; } 335 }; 336 337 template<bool DestIsTransposed, typename OtherDerived> 338 struct check_transpose_aliasing_compile_time_selector 339 { 340 enum { ret = bool(blas_traits<OtherDerived>::IsTransposed) != DestIsTransposed }; 341 }; 342 343 template<bool DestIsTransposed, typename BinOp, typename DerivedA, typename DerivedB> 344 struct check_transpose_aliasing_compile_time_selector<DestIsTransposed,CwiseBinaryOp<BinOp,DerivedA,DerivedB> > 345 { 346 enum { ret = bool(blas_traits<DerivedA>::IsTransposed) != DestIsTransposed 347 || bool(blas_traits<DerivedB>::IsTransposed) != DestIsTransposed 348 }; 349 }; 350 351 template<typename Scalar, bool DestIsTransposed, typename OtherDerived> 352 struct check_transpose_aliasing_run_time_selector 353 { 354 static bool run(const Scalar* dest, const OtherDerived& src) 355 { 356 return (bool(blas_traits<OtherDerived>::IsTransposed) != DestIsTransposed) && (dest!=0 && dest==(Scalar*)extract_data(src)); 357 } 358 }; 359 360 template<typename Scalar, bool DestIsTransposed, typename BinOp, typename DerivedA, typename DerivedB> 361 struct check_transpose_aliasing_run_time_selector<Scalar,DestIsTransposed,CwiseBinaryOp<BinOp,DerivedA,DerivedB> > 362 { 363 static bool run(const Scalar* dest, const CwiseBinaryOp<BinOp,DerivedA,DerivedB>& src) 364 { 365 return ((blas_traits<DerivedA>::IsTransposed != DestIsTransposed) && (dest!=0 && dest==(Scalar*)extract_data(src.lhs()))) 366 || ((blas_traits<DerivedB>::IsTransposed != DestIsTransposed) && (dest!=0 && dest==(Scalar*)extract_data(src.rhs()))); 367 } 368 }; 369 370 // the following selector, checkTransposeAliasing_impl, based on MightHaveTransposeAliasing, 371 // is because when the condition controlling the assert is known at compile time, ICC emits a warning. 372 // This is actually a good warning: in expressions that don't have any transposing, the condition is 373 // known at compile time to be false, and using that, we can avoid generating the code of the assert again 374 // and again for all these expressions that don't need it. 375 376 template<typename Derived, typename OtherDerived, 377 bool MightHaveTransposeAliasing 378 = check_transpose_aliasing_compile_time_selector 379 <blas_traits<Derived>::IsTransposed,OtherDerived>::ret 380 > 381 struct checkTransposeAliasing_impl 382 { 383 static void run(const Derived& dst, const OtherDerived& other) 384 { 385 eigen_assert((!check_transpose_aliasing_run_time_selector 386 <typename Derived::Scalar,blas_traits<Derived>::IsTransposed,OtherDerived> 387 ::run(extract_data(dst), other)) 388 && "aliasing detected during tranposition, use transposeInPlace() " 389 "or evaluate the rhs into a temporary using .eval()"); 390 391 } 392 }; 393 394 template<typename Derived, typename OtherDerived> 395 struct checkTransposeAliasing_impl<Derived, OtherDerived, false> 396 { 397 static void run(const Derived&, const OtherDerived&) 398 { 399 } 400 }; 401 402 } // end namespace internal 403 404 template<typename Derived> 405 template<typename OtherDerived> 406 void DenseBase<Derived>::checkTransposeAliasing(const OtherDerived& other) const 407 { 408 internal::checkTransposeAliasing_impl<Derived, OtherDerived>::run(derived(), other); 409 } 410 #endif 411 412 } // end namespace Eigen 413 414 #endif // EIGEN_TRANSPOSE_H 415
