1// This file is part of Eigen, a lightweight C++ template library
2// for linear algebra.
3//
4// Copyright (C) 2008-2011 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_PRODUCT_H
11#define EIGEN_PRODUCT_H
12
13namespace Eigen {
14
15template<typename Lhs, typename Rhs, int Option, typename StorageKind> class ProductImpl;
16
17namespace internal {
18
19template<typename Lhs, typename Rhs, int Option>
20struct traits<Product<Lhs, Rhs, Option> >
21{
22  typedef typename remove_all<Lhs>::type LhsCleaned;
23  typedef typename remove_all<Rhs>::type RhsCleaned;
24  typedef traits<LhsCleaned> LhsTraits;
25  typedef traits<RhsCleaned> RhsTraits;
26
27  typedef MatrixXpr XprKind;
28
29  typedef typename ScalarBinaryOpTraits<typename traits<LhsCleaned>::Scalar, typename traits<RhsCleaned>::Scalar>::ReturnType Scalar;
30  typedef typename product_promote_storage_type<typename LhsTraits::StorageKind,
31                                                typename RhsTraits::StorageKind,
32                                                internal::product_type<Lhs,Rhs>::ret>::ret StorageKind;
33  typedef typename promote_index_type<typename LhsTraits::StorageIndex,
34                                      typename RhsTraits::StorageIndex>::type StorageIndex;
35
36  enum {
37    RowsAtCompileTime    = LhsTraits::RowsAtCompileTime,
38    ColsAtCompileTime    = RhsTraits::ColsAtCompileTime,
39    MaxRowsAtCompileTime = LhsTraits::MaxRowsAtCompileTime,
40    MaxColsAtCompileTime = RhsTraits::MaxColsAtCompileTime,
41
42    // FIXME: only needed by GeneralMatrixMatrixTriangular
43    InnerSize = EIGEN_SIZE_MIN_PREFER_FIXED(LhsTraits::ColsAtCompileTime, RhsTraits::RowsAtCompileTime),
44
45    // The storage order is somewhat arbitrary here. The correct one will be determined through the evaluator.
46    Flags = (MaxRowsAtCompileTime==1 && MaxColsAtCompileTime!=1) ? RowMajorBit
47          : (MaxColsAtCompileTime==1 && MaxRowsAtCompileTime!=1) ? 0
48          : (   ((LhsTraits::Flags&NoPreferredStorageOrderBit) && (RhsTraits::Flags&RowMajorBit))
49             || ((RhsTraits::Flags&NoPreferredStorageOrderBit) && (LhsTraits::Flags&RowMajorBit)) ) ? RowMajorBit
50          : NoPreferredStorageOrderBit
51  };
52};
53
54} // end namespace internal
55
56/** \class Product
57  * \ingroup Core_Module
58  *
59  * \brief Expression of the product of two arbitrary matrices or vectors
60  *
61  * \tparam _Lhs the type of the left-hand side expression
62  * \tparam _Rhs the type of the right-hand side expression
63  *
64  * This class represents an expression of the product of two arbitrary matrices.
65  *
66  * The other template parameters are:
67  * \tparam Option     can be DefaultProduct, AliasFreeProduct, or LazyProduct
68  *
69  */
70template<typename _Lhs, typename _Rhs, int Option>
71class Product : public ProductImpl<_Lhs,_Rhs,Option,
72                                   typename internal::product_promote_storage_type<typename internal::traits<_Lhs>::StorageKind,
73                                                                                   typename internal::traits<_Rhs>::StorageKind,
74                                                                                   internal::product_type<_Lhs,_Rhs>::ret>::ret>
75{
76  public:
77
78    typedef _Lhs Lhs;
79    typedef _Rhs Rhs;
80
81    typedef typename ProductImpl<
82        Lhs, Rhs, Option,
83        typename internal::product_promote_storage_type<typename internal::traits<Lhs>::StorageKind,
84                                                        typename internal::traits<Rhs>::StorageKind,
85                                                        internal::product_type<Lhs,Rhs>::ret>::ret>::Base Base;
86    EIGEN_GENERIC_PUBLIC_INTERFACE(Product)
87
88    typedef typename internal::ref_selector<Lhs>::type LhsNested;
89    typedef typename internal::ref_selector<Rhs>::type RhsNested;
90    typedef typename internal::remove_all<LhsNested>::type LhsNestedCleaned;
91    typedef typename internal::remove_all<RhsNested>::type RhsNestedCleaned;
92
93    EIGEN_DEVICE_FUNC Product(const Lhs& lhs, const Rhs& rhs) : m_lhs(lhs), m_rhs(rhs)
94    {
95      eigen_assert(lhs.cols() == rhs.rows()
96        && "invalid matrix product"
97        && "if you wanted a coeff-wise or a dot product use the respective explicit functions");
98    }
99
100    EIGEN_DEVICE_FUNC inline Index rows() const { return m_lhs.rows(); }
101    EIGEN_DEVICE_FUNC inline Index cols() const { return m_rhs.cols(); }
102
103    EIGEN_DEVICE_FUNC const LhsNestedCleaned& lhs() const { return m_lhs; }
104    EIGEN_DEVICE_FUNC const RhsNestedCleaned& rhs() const { return m_rhs; }
105
106  protected:
107
108    LhsNested m_lhs;
109    RhsNested m_rhs;
110};
111
112namespace internal {
113
114template<typename Lhs, typename Rhs, int Option, int ProductTag = internal::product_type<Lhs,Rhs>::ret>
115class dense_product_base
116 : public internal::dense_xpr_base<Product<Lhs,Rhs,Option> >::type
117{};
118
119/** Convertion to scalar for inner-products */
120template<typename Lhs, typename Rhs, int Option>
121class dense_product_base<Lhs, Rhs, Option, InnerProduct>
122 : public internal::dense_xpr_base<Product<Lhs,Rhs,Option> >::type
123{
124  typedef Product<Lhs,Rhs,Option> ProductXpr;
125  typedef typename internal::dense_xpr_base<ProductXpr>::type Base;
126public:
127  using Base::derived;
128  typedef typename Base::Scalar Scalar;
129
130  operator const Scalar() const
131  {
132    return internal::evaluator<ProductXpr>(derived()).coeff(0,0);
133  }
134};
135
136} // namespace internal
137
138// Generic API dispatcher
139template<typename Lhs, typename Rhs, int Option, typename StorageKind>
140class ProductImpl : public internal::generic_xpr_base<Product<Lhs,Rhs,Option>, MatrixXpr, StorageKind>::type
141{
142  public:
143    typedef typename internal::generic_xpr_base<Product<Lhs,Rhs,Option>, MatrixXpr, StorageKind>::type Base;
144};
145
146template<typename Lhs, typename Rhs, int Option>
147class ProductImpl<Lhs,Rhs,Option,Dense>
148  : public internal::dense_product_base<Lhs,Rhs,Option>
149{
150    typedef Product<Lhs, Rhs, Option> Derived;
151
152  public:
153
154    typedef typename internal::dense_product_base<Lhs, Rhs, Option> Base;
155    EIGEN_DENSE_PUBLIC_INTERFACE(Derived)
156  protected:
157    enum {
158      IsOneByOne = (RowsAtCompileTime == 1 || RowsAtCompileTime == Dynamic) &&
159                   (ColsAtCompileTime == 1 || ColsAtCompileTime == Dynamic),
160      EnableCoeff = IsOneByOne || Option==LazyProduct
161    };
162
163  public:
164
165    EIGEN_DEVICE_FUNC Scalar coeff(Index row, Index col) const
166    {
167      EIGEN_STATIC_ASSERT(EnableCoeff, THIS_METHOD_IS_ONLY_FOR_INNER_OR_LAZY_PRODUCTS);
168      eigen_assert( (Option==LazyProduct) || (this->rows() == 1 && this->cols() == 1) );
169
170      return internal::evaluator<Derived>(derived()).coeff(row,col);
171    }
172
173    EIGEN_DEVICE_FUNC Scalar coeff(Index i) const
174    {
175      EIGEN_STATIC_ASSERT(EnableCoeff, THIS_METHOD_IS_ONLY_FOR_INNER_OR_LAZY_PRODUCTS);
176      eigen_assert( (Option==LazyProduct) || (this->rows() == 1 && this->cols() == 1) );
177
178      return internal::evaluator<Derived>(derived()).coeff(i);
179    }
180
181
182};
183
184} // end namespace Eigen
185
186#endif // EIGEN_PRODUCT_H
187