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      1 // This file is part of Eigen, a lightweight C++ template library
      2 // for linear algebra.
      3 //
      4 // Copyright (C) 2008-2010 Gael Guennebaud <gael.guennebaud (at) inria.fr>
      5 // Copyright (C) 2006-2008 Benoit Jacob <jacob.benoit.1 (at) gmail.com>
      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_PARTIAL_REDUX_H
     12 #define EIGEN_PARTIAL_REDUX_H
     13 
     14 namespace Eigen {
     15 
     16 /** \class PartialReduxExpr
     17   * \ingroup Core_Module
     18   *
     19   * \brief Generic expression of a partially reduxed matrix
     20   *
     21   * \tparam MatrixType the type of the matrix we are applying the redux operation
     22   * \tparam MemberOp type of the member functor
     23   * \tparam Direction indicates the direction of the redux (#Vertical or #Horizontal)
     24   *
     25   * This class represents an expression of a partial redux operator of a matrix.
     26   * It is the return type of some VectorwiseOp functions,
     27   * and most of the time this is the only way it is used.
     28   *
     29   * \sa class VectorwiseOp
     30   */
     31 
     32 template< typename MatrixType, typename MemberOp, int Direction>
     33 class PartialReduxExpr;
     34 
     35 namespace internal {
     36 template<typename MatrixType, typename MemberOp, int Direction>
     37 struct traits<PartialReduxExpr<MatrixType, MemberOp, Direction> >
     38  : traits<MatrixType>
     39 {
     40   typedef typename MemberOp::result_type Scalar;
     41   typedef typename traits<MatrixType>::StorageKind StorageKind;
     42   typedef typename traits<MatrixType>::XprKind XprKind;
     43   typedef typename MatrixType::Scalar InputScalar;
     44   typedef typename nested<MatrixType>::type MatrixTypeNested;
     45   typedef typename remove_all<MatrixTypeNested>::type _MatrixTypeNested;
     46   enum {
     47     RowsAtCompileTime = Direction==Vertical   ? 1 : MatrixType::RowsAtCompileTime,
     48     ColsAtCompileTime = Direction==Horizontal ? 1 : MatrixType::ColsAtCompileTime,
     49     MaxRowsAtCompileTime = Direction==Vertical   ? 1 : MatrixType::MaxRowsAtCompileTime,
     50     MaxColsAtCompileTime = Direction==Horizontal ? 1 : MatrixType::MaxColsAtCompileTime,
     51     Flags0 = (unsigned int)_MatrixTypeNested::Flags & HereditaryBits,
     52     Flags = (Flags0 & ~RowMajorBit) | (RowsAtCompileTime == 1 ? RowMajorBit : 0),
     53     TraversalSize = Direction==Vertical ? MatrixType::RowsAtCompileTime :  MatrixType::ColsAtCompileTime
     54   };
     55   #if EIGEN_GNUC_AT_LEAST(3,4)
     56   typedef typename MemberOp::template Cost<InputScalar,int(TraversalSize)> CostOpType;
     57   #else
     58   typedef typename MemberOp::template Cost<InputScalar,TraversalSize> CostOpType;
     59   #endif
     60   enum {
     61     CoeffReadCost = TraversalSize==Dynamic ? Dynamic
     62                   : TraversalSize * traits<_MatrixTypeNested>::CoeffReadCost + int(CostOpType::value)
     63   };
     64 };
     65 }
     66 
     67 template< typename MatrixType, typename MemberOp, int Direction>
     68 class PartialReduxExpr : internal::no_assignment_operator,
     69   public internal::dense_xpr_base< PartialReduxExpr<MatrixType, MemberOp, Direction> >::type
     70 {
     71   public:
     72 
     73     typedef typename internal::dense_xpr_base<PartialReduxExpr>::type Base;
     74     EIGEN_DENSE_PUBLIC_INTERFACE(PartialReduxExpr)
     75     typedef typename internal::traits<PartialReduxExpr>::MatrixTypeNested MatrixTypeNested;
     76     typedef typename internal::traits<PartialReduxExpr>::_MatrixTypeNested _MatrixTypeNested;
     77 
     78     PartialReduxExpr(const MatrixType& mat, const MemberOp& func = MemberOp())
     79       : m_matrix(mat), m_functor(func) {}
     80 
     81     Index rows() const { return (Direction==Vertical   ? 1 : m_matrix.rows()); }
     82     Index cols() const { return (Direction==Horizontal ? 1 : m_matrix.cols()); }
     83 
     84     EIGEN_STRONG_INLINE const Scalar coeff(Index i, Index j) const
     85     {
     86       if (Direction==Vertical)
     87         return m_functor(m_matrix.col(j));
     88       else
     89         return m_functor(m_matrix.row(i));
     90     }
     91 
     92     const Scalar coeff(Index index) const
     93     {
     94       if (Direction==Vertical)
     95         return m_functor(m_matrix.col(index));
     96       else
     97         return m_functor(m_matrix.row(index));
     98     }
     99 
    100   protected:
    101     MatrixTypeNested m_matrix;
    102     const MemberOp m_functor;
    103 };
    104 
    105 #define EIGEN_MEMBER_FUNCTOR(MEMBER,COST)                               \
    106   template <typename ResultType>                                        \
    107   struct member_##MEMBER {                                              \
    108     EIGEN_EMPTY_STRUCT_CTOR(member_##MEMBER)                            \
    109     typedef ResultType result_type;                                     \
    110     template<typename Scalar, int Size> struct Cost                     \
    111     { enum { value = COST }; };                                         \
    112     template<typename XprType>                                          \
    113     EIGEN_STRONG_INLINE ResultType operator()(const XprType& mat) const \
    114     { return mat.MEMBER(); } \
    115   }
    116 
    117 namespace internal {
    118 
    119 EIGEN_MEMBER_FUNCTOR(squaredNorm, Size * NumTraits<Scalar>::MulCost + (Size-1)*NumTraits<Scalar>::AddCost);
    120 EIGEN_MEMBER_FUNCTOR(norm, (Size+5) * NumTraits<Scalar>::MulCost + (Size-1)*NumTraits<Scalar>::AddCost);
    121 EIGEN_MEMBER_FUNCTOR(stableNorm, (Size+5) * NumTraits<Scalar>::MulCost + (Size-1)*NumTraits<Scalar>::AddCost);
    122 EIGEN_MEMBER_FUNCTOR(blueNorm, (Size+5) * NumTraits<Scalar>::MulCost + (Size-1)*NumTraits<Scalar>::AddCost);
    123 EIGEN_MEMBER_FUNCTOR(hypotNorm, (Size-1) * functor_traits<scalar_hypot_op<Scalar> >::Cost );
    124 EIGEN_MEMBER_FUNCTOR(sum, (Size-1)*NumTraits<Scalar>::AddCost);
    125 EIGEN_MEMBER_FUNCTOR(mean, (Size-1)*NumTraits<Scalar>::AddCost + NumTraits<Scalar>::MulCost);
    126 EIGEN_MEMBER_FUNCTOR(minCoeff, (Size-1)*NumTraits<Scalar>::AddCost);
    127 EIGEN_MEMBER_FUNCTOR(maxCoeff, (Size-1)*NumTraits<Scalar>::AddCost);
    128 EIGEN_MEMBER_FUNCTOR(all, (Size-1)*NumTraits<Scalar>::AddCost);
    129 EIGEN_MEMBER_FUNCTOR(any, (Size-1)*NumTraits<Scalar>::AddCost);
    130 EIGEN_MEMBER_FUNCTOR(count, (Size-1)*NumTraits<Scalar>::AddCost);
    131 EIGEN_MEMBER_FUNCTOR(prod, (Size-1)*NumTraits<Scalar>::MulCost);
    132 
    133 
    134 template <typename BinaryOp, typename Scalar>
    135 struct member_redux {
    136   typedef typename result_of<
    137                      BinaryOp(Scalar)
    138                    >::type  result_type;
    139   template<typename _Scalar, int Size> struct Cost
    140   { enum { value = (Size-1) * functor_traits<BinaryOp>::Cost }; };
    141   member_redux(const BinaryOp func) : m_functor(func) {}
    142   template<typename Derived>
    143   inline result_type operator()(const DenseBase<Derived>& mat) const
    144   { return mat.redux(m_functor); }
    145   const BinaryOp m_functor;
    146 };
    147 }
    148 
    149 /** \class VectorwiseOp
    150   * \ingroup Core_Module
    151   *
    152   * \brief Pseudo expression providing partial reduction operations
    153   *
    154   * \param ExpressionType the type of the object on which to do partial reductions
    155   * \param Direction indicates the direction of the redux (#Vertical or #Horizontal)
    156   *
    157   * This class represents a pseudo expression with partial reduction features.
    158   * It is the return type of DenseBase::colwise() and DenseBase::rowwise()
    159   * and most of the time this is the only way it is used.
    160   *
    161   * Example: \include MatrixBase_colwise.cpp
    162   * Output: \verbinclude MatrixBase_colwise.out
    163   *
    164   * \sa DenseBase::colwise(), DenseBase::rowwise(), class PartialReduxExpr
    165   */
    166 template<typename ExpressionType, int Direction> class VectorwiseOp
    167 {
    168   public:
    169 
    170     typedef typename ExpressionType::Scalar Scalar;
    171     typedef typename ExpressionType::RealScalar RealScalar;
    172     typedef typename ExpressionType::Index Index;
    173     typedef typename internal::conditional<internal::must_nest_by_value<ExpressionType>::ret,
    174         ExpressionType, ExpressionType&>::type ExpressionTypeNested;
    175     typedef typename internal::remove_all<ExpressionTypeNested>::type ExpressionTypeNestedCleaned;
    176 
    177     template<template<typename _Scalar> class Functor,
    178                       typename Scalar=typename internal::traits<ExpressionType>::Scalar> struct ReturnType
    179     {
    180       typedef PartialReduxExpr<ExpressionType,
    181                                Functor<Scalar>,
    182                                Direction
    183                               > Type;
    184     };
    185 
    186     template<typename BinaryOp> struct ReduxReturnType
    187     {
    188       typedef PartialReduxExpr<ExpressionType,
    189                                internal::member_redux<BinaryOp,typename internal::traits<ExpressionType>::Scalar>,
    190                                Direction
    191                               > Type;
    192     };
    193 
    194     enum {
    195       IsVertical   = (Direction==Vertical) ? 1 : 0,
    196       IsHorizontal = (Direction==Horizontal) ? 1 : 0
    197     };
    198 
    199   protected:
    200 
    201     /** \internal
    202       * \returns the i-th subvector according to the \c Direction */
    203     typedef typename internal::conditional<Direction==Vertical,
    204                                typename ExpressionType::ColXpr,
    205                                typename ExpressionType::RowXpr>::type SubVector;
    206     SubVector subVector(Index i)
    207     {
    208       return SubVector(m_matrix.derived(),i);
    209     }
    210 
    211     /** \internal
    212       * \returns the number of subvectors in the direction \c Direction */
    213     Index subVectors() const
    214     { return Direction==Vertical?m_matrix.cols():m_matrix.rows(); }
    215 
    216     template<typename OtherDerived> struct ExtendedType {
    217       typedef Replicate<OtherDerived,
    218                         Direction==Vertical   ? 1 : ExpressionType::RowsAtCompileTime,
    219                         Direction==Horizontal ? 1 : ExpressionType::ColsAtCompileTime> Type;
    220     };
    221 
    222     /** \internal
    223       * Replicates a vector to match the size of \c *this */
    224     template<typename OtherDerived>
    225     typename ExtendedType<OtherDerived>::Type
    226     extendedTo(const DenseBase<OtherDerived>& other) const
    227     {
    228       EIGEN_STATIC_ASSERT(EIGEN_IMPLIES(Direction==Vertical, OtherDerived::MaxColsAtCompileTime==1),
    229                           YOU_PASSED_A_ROW_VECTOR_BUT_A_COLUMN_VECTOR_WAS_EXPECTED)
    230       EIGEN_STATIC_ASSERT(EIGEN_IMPLIES(Direction==Horizontal, OtherDerived::MaxRowsAtCompileTime==1),
    231                           YOU_PASSED_A_COLUMN_VECTOR_BUT_A_ROW_VECTOR_WAS_EXPECTED)
    232       return typename ExtendedType<OtherDerived>::Type
    233                       (other.derived(),
    234                        Direction==Vertical   ? 1 : m_matrix.rows(),
    235                        Direction==Horizontal ? 1 : m_matrix.cols());
    236     }
    237 
    238     template<typename OtherDerived> struct OppositeExtendedType {
    239       typedef Replicate<OtherDerived,
    240                         Direction==Horizontal ? 1 : ExpressionType::RowsAtCompileTime,
    241                         Direction==Vertical   ? 1 : ExpressionType::ColsAtCompileTime> Type;
    242     };
    243 
    244     /** \internal
    245       * Replicates a vector in the opposite direction to match the size of \c *this */
    246     template<typename OtherDerived>
    247     typename OppositeExtendedType<OtherDerived>::Type
    248     extendedToOpposite(const DenseBase<OtherDerived>& other) const
    249     {
    250       EIGEN_STATIC_ASSERT(EIGEN_IMPLIES(Direction==Horizontal, OtherDerived::MaxColsAtCompileTime==1),
    251                           YOU_PASSED_A_ROW_VECTOR_BUT_A_COLUMN_VECTOR_WAS_EXPECTED)
    252       EIGEN_STATIC_ASSERT(EIGEN_IMPLIES(Direction==Vertical, OtherDerived::MaxRowsAtCompileTime==1),
    253                           YOU_PASSED_A_COLUMN_VECTOR_BUT_A_ROW_VECTOR_WAS_EXPECTED)
    254       return typename OppositeExtendedType<OtherDerived>::Type
    255                       (other.derived(),
    256                        Direction==Horizontal  ? 1 : m_matrix.rows(),
    257                        Direction==Vertical    ? 1 : m_matrix.cols());
    258     }
    259 
    260   public:
    261 
    262     inline VectorwiseOp(ExpressionType& matrix) : m_matrix(matrix) {}
    263 
    264     /** \internal */
    265     inline const ExpressionType& _expression() const { return m_matrix; }
    266 
    267     /** \returns a row or column vector expression of \c *this reduxed by \a func
    268       *
    269       * The template parameter \a BinaryOp is the type of the functor
    270       * of the custom redux operator. Note that func must be an associative operator.
    271       *
    272       * \sa class VectorwiseOp, DenseBase::colwise(), DenseBase::rowwise()
    273       */
    274     template<typename BinaryOp>
    275     const typename ReduxReturnType<BinaryOp>::Type
    276     redux(const BinaryOp& func = BinaryOp()) const
    277     { return typename ReduxReturnType<BinaryOp>::Type(_expression(), func); }
    278 
    279     /** \returns a row (or column) vector expression of the smallest coefficient
    280       * of each column (or row) of the referenced expression.
    281       *
    282       * \warning the result is undefined if \c *this contains NaN.
    283       *
    284       * Example: \include PartialRedux_minCoeff.cpp
    285       * Output: \verbinclude PartialRedux_minCoeff.out
    286       *
    287       * \sa DenseBase::minCoeff() */
    288     const typename ReturnType<internal::member_minCoeff>::Type minCoeff() const
    289     { return _expression(); }
    290 
    291     /** \returns a row (or column) vector expression of the largest coefficient
    292       * of each column (or row) of the referenced expression.
    293       *
    294       * \warning the result is undefined if \c *this contains NaN.
    295       *
    296       * Example: \include PartialRedux_maxCoeff.cpp
    297       * Output: \verbinclude PartialRedux_maxCoeff.out
    298       *
    299       * \sa DenseBase::maxCoeff() */
    300     const typename ReturnType<internal::member_maxCoeff>::Type maxCoeff() const
    301     { return _expression(); }
    302 
    303     /** \returns a row (or column) vector expression of the squared norm
    304       * of each column (or row) of the referenced expression.
    305       *
    306       * Example: \include PartialRedux_squaredNorm.cpp
    307       * Output: \verbinclude PartialRedux_squaredNorm.out
    308       *
    309       * \sa DenseBase::squaredNorm() */
    310     const typename ReturnType<internal::member_squaredNorm,RealScalar>::Type squaredNorm() const
    311     { return _expression(); }
    312 
    313     /** \returns a row (or column) vector expression of the norm
    314       * of each column (or row) of the referenced expression.
    315       *
    316       * Example: \include PartialRedux_norm.cpp
    317       * Output: \verbinclude PartialRedux_norm.out
    318       *
    319       * \sa DenseBase::norm() */
    320     const typename ReturnType<internal::member_norm,RealScalar>::Type norm() const
    321     { return _expression(); }
    322 
    323 
    324     /** \returns a row (or column) vector expression of the norm
    325       * of each column (or row) of the referenced expression, using
    326       * blue's algorithm.
    327       *
    328       * \sa DenseBase::blueNorm() */
    329     const typename ReturnType<internal::member_blueNorm,RealScalar>::Type blueNorm() const
    330     { return _expression(); }
    331 
    332 
    333     /** \returns a row (or column) vector expression of the norm
    334       * of each column (or row) of the referenced expression, avoiding
    335       * underflow and overflow.
    336       *
    337       * \sa DenseBase::stableNorm() */
    338     const typename ReturnType<internal::member_stableNorm,RealScalar>::Type stableNorm() const
    339     { return _expression(); }
    340 
    341 
    342     /** \returns a row (or column) vector expression of the norm
    343       * of each column (or row) of the referenced expression, avoiding
    344       * underflow and overflow using a concatenation of hypot() calls.
    345       *
    346       * \sa DenseBase::hypotNorm() */
    347     const typename ReturnType<internal::member_hypotNorm,RealScalar>::Type hypotNorm() const
    348     { return _expression(); }
    349 
    350     /** \returns a row (or column) vector expression of the sum
    351       * of each column (or row) of the referenced expression.
    352       *
    353       * Example: \include PartialRedux_sum.cpp
    354       * Output: \verbinclude PartialRedux_sum.out
    355       *
    356       * \sa DenseBase::sum() */
    357     const typename ReturnType<internal::member_sum>::Type sum() const
    358     { return _expression(); }
    359 
    360     /** \returns a row (or column) vector expression of the mean
    361     * of each column (or row) of the referenced expression.
    362     *
    363     * \sa DenseBase::mean() */
    364     const typename ReturnType<internal::member_mean>::Type mean() const
    365     { return _expression(); }
    366 
    367     /** \returns a row (or column) vector expression representing
    368       * whether \b all coefficients of each respective column (or row) are \c true.
    369       *
    370       * \sa DenseBase::all() */
    371     const typename ReturnType<internal::member_all>::Type all() const
    372     { return _expression(); }
    373 
    374     /** \returns a row (or column) vector expression representing
    375       * whether \b at \b least one coefficient of each respective column (or row) is \c true.
    376       *
    377       * \sa DenseBase::any() */
    378     const typename ReturnType<internal::member_any>::Type any() const
    379     { return _expression(); }
    380 
    381     /** \returns a row (or column) vector expression representing
    382       * the number of \c true coefficients of each respective column (or row).
    383       *
    384       * Example: \include PartialRedux_count.cpp
    385       * Output: \verbinclude PartialRedux_count.out
    386       *
    387       * \sa DenseBase::count() */
    388     const PartialReduxExpr<ExpressionType, internal::member_count<Index>, Direction> count() const
    389     { return _expression(); }
    390 
    391     /** \returns a row (or column) vector expression of the product
    392       * of each column (or row) of the referenced expression.
    393       *
    394       * Example: \include PartialRedux_prod.cpp
    395       * Output: \verbinclude PartialRedux_prod.out
    396       *
    397       * \sa DenseBase::prod() */
    398     const typename ReturnType<internal::member_prod>::Type prod() const
    399     { return _expression(); }
    400 
    401 
    402     /** \returns a matrix expression
    403       * where each column (or row) are reversed.
    404       *
    405       * Example: \include Vectorwise_reverse.cpp
    406       * Output: \verbinclude Vectorwise_reverse.out
    407       *
    408       * \sa DenseBase::reverse() */
    409     const Reverse<ExpressionType, Direction> reverse() const
    410     { return Reverse<ExpressionType, Direction>( _expression() ); }
    411 
    412     typedef Replicate<ExpressionType,Direction==Vertical?Dynamic:1,Direction==Horizontal?Dynamic:1> ReplicateReturnType;
    413     const ReplicateReturnType replicate(Index factor) const;
    414 
    415     /**
    416       * \return an expression of the replication of each column (or row) of \c *this
    417       *
    418       * Example: \include DirectionWise_replicate.cpp
    419       * Output: \verbinclude DirectionWise_replicate.out
    420       *
    421       * \sa VectorwiseOp::replicate(Index), DenseBase::replicate(), class Replicate
    422       */
    423     // NOTE implemented here because of sunstudio's compilation errors
    424     template<int Factor> const Replicate<ExpressionType,(IsVertical?Factor:1),(IsHorizontal?Factor:1)>
    425     replicate(Index factor = Factor) const
    426     {
    427       return Replicate<ExpressionType,Direction==Vertical?Factor:1,Direction==Horizontal?Factor:1>
    428           (_expression(),Direction==Vertical?factor:1,Direction==Horizontal?factor:1);
    429     }
    430 
    431 /////////// Artithmetic operators ///////////
    432 
    433     /** Copies the vector \a other to each subvector of \c *this */
    434     template<typename OtherDerived>
    435     ExpressionType& operator=(const DenseBase<OtherDerived>& other)
    436     {
    437       EIGEN_STATIC_ASSERT_VECTOR_ONLY(OtherDerived)
    438       EIGEN_STATIC_ASSERT_SAME_XPR_KIND(ExpressionType, OtherDerived)
    439       //eigen_assert((m_matrix.isNull()) == (other.isNull())); FIXME
    440       return const_cast<ExpressionType&>(m_matrix = extendedTo(other.derived()));
    441     }
    442 
    443     /** Adds the vector \a other to each subvector of \c *this */
    444     template<typename OtherDerived>
    445     ExpressionType& operator+=(const DenseBase<OtherDerived>& other)
    446     {
    447       EIGEN_STATIC_ASSERT_VECTOR_ONLY(OtherDerived)
    448       EIGEN_STATIC_ASSERT_SAME_XPR_KIND(ExpressionType, OtherDerived)
    449       return const_cast<ExpressionType&>(m_matrix += extendedTo(other.derived()));
    450     }
    451 
    452     /** Substracts the vector \a other to each subvector of \c *this */
    453     template<typename OtherDerived>
    454     ExpressionType& operator-=(const DenseBase<OtherDerived>& other)
    455     {
    456       EIGEN_STATIC_ASSERT_VECTOR_ONLY(OtherDerived)
    457       EIGEN_STATIC_ASSERT_SAME_XPR_KIND(ExpressionType, OtherDerived)
    458       return const_cast<ExpressionType&>(m_matrix -= extendedTo(other.derived()));
    459     }
    460 
    461     /** Multiples each subvector of \c *this by the vector \a other */
    462     template<typename OtherDerived>
    463     ExpressionType& operator*=(const DenseBase<OtherDerived>& other)
    464     {
    465       EIGEN_STATIC_ASSERT_VECTOR_ONLY(OtherDerived)
    466       EIGEN_STATIC_ASSERT_ARRAYXPR(ExpressionType)
    467       EIGEN_STATIC_ASSERT_SAME_XPR_KIND(ExpressionType, OtherDerived)
    468       m_matrix *= extendedTo(other.derived());
    469       return const_cast<ExpressionType&>(m_matrix);
    470     }
    471 
    472     /** Divides each subvector of \c *this by the vector \a other */
    473     template<typename OtherDerived>
    474     ExpressionType& operator/=(const DenseBase<OtherDerived>& other)
    475     {
    476       EIGEN_STATIC_ASSERT_VECTOR_ONLY(OtherDerived)
    477       EIGEN_STATIC_ASSERT_ARRAYXPR(ExpressionType)
    478       EIGEN_STATIC_ASSERT_SAME_XPR_KIND(ExpressionType, OtherDerived)
    479       m_matrix /= extendedTo(other.derived());
    480       return const_cast<ExpressionType&>(m_matrix);
    481     }
    482 
    483     /** Returns the expression of the sum of the vector \a other to each subvector of \c *this */
    484     template<typename OtherDerived> EIGEN_STRONG_INLINE
    485     CwiseBinaryOp<internal::scalar_sum_op<Scalar>,
    486                   const ExpressionTypeNestedCleaned,
    487                   const typename ExtendedType<OtherDerived>::Type>
    488     operator+(const DenseBase<OtherDerived>& other) const
    489     {
    490       EIGEN_STATIC_ASSERT_VECTOR_ONLY(OtherDerived)
    491       EIGEN_STATIC_ASSERT_SAME_XPR_KIND(ExpressionType, OtherDerived)
    492       return m_matrix + extendedTo(other.derived());
    493     }
    494 
    495     /** Returns the expression of the difference between each subvector of \c *this and the vector \a other */
    496     template<typename OtherDerived>
    497     CwiseBinaryOp<internal::scalar_difference_op<Scalar>,
    498                   const ExpressionTypeNestedCleaned,
    499                   const typename ExtendedType<OtherDerived>::Type>
    500     operator-(const DenseBase<OtherDerived>& other) const
    501     {
    502       EIGEN_STATIC_ASSERT_VECTOR_ONLY(OtherDerived)
    503       EIGEN_STATIC_ASSERT_SAME_XPR_KIND(ExpressionType, OtherDerived)
    504       return m_matrix - extendedTo(other.derived());
    505     }
    506 
    507     /** Returns the expression where each subvector is the product of the vector \a other
    508       * by the corresponding subvector of \c *this */
    509     template<typename OtherDerived> EIGEN_STRONG_INLINE
    510     CwiseBinaryOp<internal::scalar_product_op<Scalar>,
    511                   const ExpressionTypeNestedCleaned,
    512                   const typename ExtendedType<OtherDerived>::Type>
    513     operator*(const DenseBase<OtherDerived>& other) const
    514     {
    515       EIGEN_STATIC_ASSERT_VECTOR_ONLY(OtherDerived)
    516       EIGEN_STATIC_ASSERT_ARRAYXPR(ExpressionType)
    517       EIGEN_STATIC_ASSERT_SAME_XPR_KIND(ExpressionType, OtherDerived)
    518       return m_matrix * extendedTo(other.derived());
    519     }
    520 
    521     /** Returns the expression where each subvector is the quotient of the corresponding
    522       * subvector of \c *this by the vector \a other */
    523     template<typename OtherDerived>
    524     CwiseBinaryOp<internal::scalar_quotient_op<Scalar>,
    525                   const ExpressionTypeNestedCleaned,
    526                   const typename ExtendedType<OtherDerived>::Type>
    527     operator/(const DenseBase<OtherDerived>& other) const
    528     {
    529       EIGEN_STATIC_ASSERT_VECTOR_ONLY(OtherDerived)
    530       EIGEN_STATIC_ASSERT_ARRAYXPR(ExpressionType)
    531       EIGEN_STATIC_ASSERT_SAME_XPR_KIND(ExpressionType, OtherDerived)
    532       return m_matrix / extendedTo(other.derived());
    533     }
    534 
    535     /** \returns an expression where each column of row of the referenced matrix are normalized.
    536       * The referenced matrix is \b not modified.
    537       * \sa MatrixBase::normalized(), normalize()
    538       */
    539     CwiseBinaryOp<internal::scalar_quotient_op<Scalar>,
    540                   const ExpressionTypeNestedCleaned,
    541                   const typename OppositeExtendedType<typename ReturnType<internal::member_norm,RealScalar>::Type>::Type>
    542     normalized() const { return m_matrix.cwiseQuotient(extendedToOpposite(this->norm())); }
    543 
    544 
    545     /** Normalize in-place each row or columns of the referenced matrix.
    546       * \sa MatrixBase::normalize(), normalized()
    547       */
    548     void normalize() {
    549       m_matrix = this->normalized();
    550     }
    551 
    552 /////////// Geometry module ///////////
    553 
    554     #if EIGEN2_SUPPORT_STAGE > STAGE20_RESOLVE_API_CONFLICTS
    555     Homogeneous<ExpressionType,Direction> homogeneous() const;
    556     #endif
    557 
    558     typedef typename ExpressionType::PlainObject CrossReturnType;
    559     template<typename OtherDerived>
    560     const CrossReturnType cross(const MatrixBase<OtherDerived>& other) const;
    561 
    562     enum {
    563       HNormalized_Size = Direction==Vertical ? internal::traits<ExpressionType>::RowsAtCompileTime
    564                                              : internal::traits<ExpressionType>::ColsAtCompileTime,
    565       HNormalized_SizeMinusOne = HNormalized_Size==Dynamic ? Dynamic : HNormalized_Size-1
    566     };
    567     typedef Block<const ExpressionType,
    568                   Direction==Vertical   ? int(HNormalized_SizeMinusOne)
    569                                         : int(internal::traits<ExpressionType>::RowsAtCompileTime),
    570                   Direction==Horizontal ? int(HNormalized_SizeMinusOne)
    571                                         : int(internal::traits<ExpressionType>::ColsAtCompileTime)>
    572             HNormalized_Block;
    573     typedef Block<const ExpressionType,
    574                   Direction==Vertical   ? 1 : int(internal::traits<ExpressionType>::RowsAtCompileTime),
    575                   Direction==Horizontal ? 1 : int(internal::traits<ExpressionType>::ColsAtCompileTime)>
    576             HNormalized_Factors;
    577     typedef CwiseBinaryOp<internal::scalar_quotient_op<typename internal::traits<ExpressionType>::Scalar>,
    578                 const HNormalized_Block,
    579                 const Replicate<HNormalized_Factors,
    580                   Direction==Vertical   ? HNormalized_SizeMinusOne : 1,
    581                   Direction==Horizontal ? HNormalized_SizeMinusOne : 1> >
    582             HNormalizedReturnType;
    583 
    584     const HNormalizedReturnType hnormalized() const;
    585 
    586   protected:
    587     ExpressionTypeNested m_matrix;
    588 };
    589 
    590 /** \returns a VectorwiseOp wrapper of *this providing additional partial reduction operations
    591   *
    592   * Example: \include MatrixBase_colwise.cpp
    593   * Output: \verbinclude MatrixBase_colwise.out
    594   *
    595   * \sa rowwise(), class VectorwiseOp, \ref TutorialReductionsVisitorsBroadcasting
    596   */
    597 template<typename Derived>
    598 inline const typename DenseBase<Derived>::ConstColwiseReturnType
    599 DenseBase<Derived>::colwise() const
    600 {
    601   return derived();
    602 }
    603 
    604 /** \returns a writable VectorwiseOp wrapper of *this providing additional partial reduction operations
    605   *
    606   * \sa rowwise(), class VectorwiseOp, \ref TutorialReductionsVisitorsBroadcasting
    607   */
    608 template<typename Derived>
    609 inline typename DenseBase<Derived>::ColwiseReturnType
    610 DenseBase<Derived>::colwise()
    611 {
    612   return derived();
    613 }
    614 
    615 /** \returns a VectorwiseOp wrapper of *this providing additional partial reduction operations
    616   *
    617   * Example: \include MatrixBase_rowwise.cpp
    618   * Output: \verbinclude MatrixBase_rowwise.out
    619   *
    620   * \sa colwise(), class VectorwiseOp, \ref TutorialReductionsVisitorsBroadcasting
    621   */
    622 template<typename Derived>
    623 inline const typename DenseBase<Derived>::ConstRowwiseReturnType
    624 DenseBase<Derived>::rowwise() const
    625 {
    626   return derived();
    627 }
    628 
    629 /** \returns a writable VectorwiseOp wrapper of *this providing additional partial reduction operations
    630   *
    631   * \sa colwise(), class VectorwiseOp, \ref TutorialReductionsVisitorsBroadcasting
    632   */
    633 template<typename Derived>
    634 inline typename DenseBase<Derived>::RowwiseReturnType
    635 DenseBase<Derived>::rowwise()
    636 {
    637   return derived();
    638 }
    639 
    640 } // end namespace Eigen
    641 
    642 #endif // EIGEN_PARTIAL_REDUX_H
    643