DiagonalProduct.h

00001 // This file is part of Eigen, a lightweight C++ template library
00002 // for linear algebra.
00003 //
00004 // Copyright (C) 2008 Gael Guennebaud <gael.guennebaud@inria.fr>
00005 // Copyright (C) 2007-2009 Benoit Jacob <jacob.benoit.1@gmail.com>
00006 //
00007 // This Source Code Form is subject to the terms of the Mozilla
00008 // Public License v. 2.0. If a copy of the MPL was not distributed
00009 // with this file, You can obtain one at http://mozilla.org/MPL/2.0/.
00010 
00011 #ifndef EIGEN_DIAGONALPRODUCT_H
00012 #define EIGEN_DIAGONALPRODUCT_H
00013 
00014 namespace Eigen { 
00015 
00016 namespace internal {
00017 template<typename MatrixType, typename DiagonalType, int ProductOrder>
00018 struct traits<DiagonalProduct<MatrixType, DiagonalType, ProductOrder> >
00019  : traits<MatrixType>
00020 {
00021   typedef typename scalar_product_traits<typename MatrixType::Scalar, typename DiagonalType::Scalar>::ReturnType Scalar;
00022   enum {
00023     RowsAtCompileTime = MatrixType::RowsAtCompileTime,
00024     ColsAtCompileTime = MatrixType::ColsAtCompileTime,
00025     MaxRowsAtCompileTime = MatrixType::MaxRowsAtCompileTime,
00026     MaxColsAtCompileTime = MatrixType::MaxColsAtCompileTime,
00027 
00028     _StorageOrder = MatrixType::Flags & RowMajorBit ? RowMajor : ColMajor,
00029     _ScalarAccessOnDiag =  !((int(_StorageOrder) == ColMajor && int(ProductOrder) == OnTheLeft)
00030                           ||(int(_StorageOrder) == RowMajor && int(ProductOrder) == OnTheRight)),
00031     _SameTypes = is_same<typename MatrixType::Scalar, typename DiagonalType::Scalar>::value,
00032     // FIXME currently we need same types, but in the future the next rule should be the one
00033     //_Vectorizable = bool(int(MatrixType::Flags)&PacketAccessBit) && ((!_PacketOnDiag) || (_SameTypes && bool(int(DiagonalType::DiagonalVectorType::Flags)&PacketAccessBit))),
00034     _Vectorizable = bool(int(MatrixType::Flags)&PacketAccessBit) && _SameTypes && (_ScalarAccessOnDiag || (bool(int(DiagonalType::DiagonalVectorType::Flags)&PacketAccessBit))),
00035     _LinearAccessMask = (RowsAtCompileTime==1 || ColsAtCompileTime==1) ? LinearAccessBit : 0,
00036 
00037     Flags = ((HereditaryBits|_LinearAccessMask|AlignedBit) & (unsigned int)(MatrixType::Flags)) | (_Vectorizable ? PacketAccessBit : 0),//(int(MatrixType::Flags)&int(DiagonalType::DiagonalVectorType::Flags)&AlignedBit),
00038     Cost0 = EIGEN_ADD_COST(NumTraits<Scalar>::MulCost, MatrixType::CoeffReadCost),
00039     CoeffReadCost = EIGEN_ADD_COST(Cost0,DiagonalType::DiagonalVectorType::CoeffReadCost)
00040   };
00041 };
00042 }
00043 
00044 template<typename MatrixType, typename DiagonalType, int ProductOrder>
00045 class DiagonalProduct : internal::no_assignment_operator,
00046                         public MatrixBase<DiagonalProduct<MatrixType, DiagonalType, ProductOrder> >
00047 {
00048   public:
00049 
00050     typedef MatrixBase<DiagonalProduct> Base;
00051     EIGEN_DENSE_PUBLIC_INTERFACE(DiagonalProduct)
00052 
00053     inline DiagonalProduct(const MatrixType& matrix, const DiagonalType& diagonal)
00054       : m_matrix(matrix), m_diagonal(diagonal)
00055     {
00056       eigen_assert(diagonal.diagonal().size() == (ProductOrder == OnTheLeft ? matrix.rows() : matrix.cols()));
00057     }
00058 
00059     EIGEN_STRONG_INLINE Index rows() const { return m_matrix.rows(); }
00060     EIGEN_STRONG_INLINE Index cols() const { return m_matrix.cols(); }
00061 
00062     EIGEN_STRONG_INLINE const Scalar coeff(Index row, Index col) const
00063     {
00064       return m_diagonal.diagonal().coeff(ProductOrder == OnTheLeft ? row : col) * m_matrix.coeff(row, col);
00065     }
00066     
00067     EIGEN_STRONG_INLINE const Scalar coeff(Index idx) const
00068     {
00069       enum {
00070         StorageOrder = int(MatrixType::Flags) & RowMajorBit ? RowMajor : ColMajor
00071       };
00072       return coeff(int(StorageOrder)==ColMajor?idx:0,int(StorageOrder)==ColMajor?0:idx);
00073     }
00074 
00075     template<int LoadMode>
00076     EIGEN_STRONG_INLINE PacketScalar packet(Index row, Index col) const
00077     {
00078       enum {
00079         StorageOrder = Flags & RowMajorBit ? RowMajor : ColMajor
00080       };
00081       const Index indexInDiagonalVector = ProductOrder == OnTheLeft ? row : col;
00082       return packet_impl<LoadMode>(row,col,indexInDiagonalVector,typename internal::conditional<
00083         ((int(StorageOrder) == RowMajor && int(ProductOrder) == OnTheLeft)
00084        ||(int(StorageOrder) == ColMajor && int(ProductOrder) == OnTheRight)), internal::true_type, internal::false_type>::type());
00085     }
00086     
00087     template<int LoadMode>
00088     EIGEN_STRONG_INLINE PacketScalar packet(Index idx) const
00089     {
00090       enum {
00091         StorageOrder = int(MatrixType::Flags) & RowMajorBit ? RowMajor : ColMajor
00092       };
00093       return packet<LoadMode>(int(StorageOrder)==ColMajor?idx:0,int(StorageOrder)==ColMajor?0:idx);
00094     }
00095 
00096   protected:
00097     template<int LoadMode>
00098     EIGEN_STRONG_INLINE PacketScalar packet_impl(Index row, Index col, Index id, internal::true_type) const
00099     {
00100       return internal::pmul(m_matrix.template packet<LoadMode>(row, col),
00101                      internal::pset1<PacketScalar>(m_diagonal.diagonal().coeff(id)));
00102     }
00103 
00104     template<int LoadMode>
00105     EIGEN_STRONG_INLINE PacketScalar packet_impl(Index row, Index col, Index id, internal::false_type) const
00106     {
00107       enum {
00108         InnerSize = (MatrixType::Flags & RowMajorBit) ? MatrixType::ColsAtCompileTime : MatrixType::RowsAtCompileTime,
00109         DiagonalVectorPacketLoadMode = (LoadMode == Aligned && (((InnerSize%16) == 0) || (int(DiagonalType::DiagonalVectorType::Flags)&AlignedBit)==AlignedBit) ? Aligned : Unaligned)
00110       };
00111       return internal::pmul(m_matrix.template packet<LoadMode>(row, col),
00112                      m_diagonal.diagonal().template packet<DiagonalVectorPacketLoadMode>(id));
00113     }
00114 
00115     typename MatrixType::Nested m_matrix;
00116     typename DiagonalType::Nested m_diagonal;
00117 };
00118 
00119 /** \returns the diagonal matrix product of \c *this by the diagonal matrix \a diagonal.
00120   */
00121 template<typename Derived>
00122 template<typename DiagonalDerived>
00123 inline const DiagonalProduct<Derived, DiagonalDerived, OnTheRight>
00124 MatrixBase<Derived>::operator* (const DiagonalBase<DiagonalDerived> &a_diagonal) const
00125 {
00126   return DiagonalProduct<Derived, DiagonalDerived, OnTheRight>(derived(), a_diagonal.derived());
00127 }
00128 
00129 } // end namespace Eigen
00130 
00131 #endif // EIGEN_DIAGONALPRODUCT_H