HouseholderSequence.h
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00001 // This file is part of Eigen, a lightweight C++ template library
00002 // for linear algebra.
00003 //
00004 // Copyright (C) 2009 Gael Guennebaud <gael.guennebaud@inria.fr>
00005 // Copyright (C) 2010 Benoit Jacob <jacob.benoit.1@gmail.com>
00006 //
00007 // Eigen is free software; you can redistribute it and/or
00008 // modify it under the terms of the GNU Lesser General Public
00009 // License as published by the Free Software Foundation; either
00010 // version 3 of the License, or (at your option) any later version.
00011 //
00012 // Alternatively, you can redistribute it and/or
00013 // modify it under the terms of the GNU General Public License as
00014 // published by the Free Software Foundation; either version 2 of
00015 // the License, or (at your option) any later version.
00016 //
00017 // Eigen is distributed in the hope that it will be useful, but WITHOUT ANY
00018 // WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
00019 // FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License or the
00020 // GNU General Public License for more details.
00021 //
00022 // You should have received a copy of the GNU Lesser General Public
00023 // License and a copy of the GNU General Public License along with
00024 // Eigen. If not, see <http://www.gnu.org/licenses/>.
00025 
00026 #ifndef EIGEN_HOUSEHOLDER_SEQUENCE_H
00027 #define EIGEN_HOUSEHOLDER_SEQUENCE_H
00028 
00070 namespace internal {
00071 
00072 template<typename VectorsType, typename CoeffsType, int Side>
00073 struct traits<HouseholderSequence<VectorsType,CoeffsType,Side> >
00074 {
00075   typedef typename VectorsType::Scalar Scalar;
00076   typedef typename VectorsType::Index Index;
00077   typedef typename VectorsType::StorageKind StorageKind;
00078   enum {
00079     RowsAtCompileTime = Side==OnTheLeft ? traits<VectorsType>::RowsAtCompileTime
00080                                         : traits<VectorsType>::ColsAtCompileTime,
00081     ColsAtCompileTime = RowsAtCompileTime,
00082     MaxRowsAtCompileTime = Side==OnTheLeft ? traits<VectorsType>::MaxRowsAtCompileTime
00083                                            : traits<VectorsType>::MaxColsAtCompileTime,
00084     MaxColsAtCompileTime = MaxRowsAtCompileTime,
00085     Flags = 0
00086   };
00087 };
00088 
00089 template<typename VectorsType, typename CoeffsType, int Side>
00090 struct hseq_side_dependent_impl
00091 {
00092   typedef Block<const VectorsType, Dynamic, 1> EssentialVectorType;
00093   typedef HouseholderSequence<VectorsType, CoeffsType, OnTheLeft> HouseholderSequenceType;
00094   typedef typename VectorsType::Index Index;
00095   static inline const EssentialVectorType essentialVector(const HouseholderSequenceType& h, Index k)
00096   {
00097     Index start = k+1+h.m_shift;
00098     return Block<const VectorsType,Dynamic,1>(h.m_vectors, start, k, h.rows()-start, 1);
00099   }
00100 };
00101 
00102 template<typename VectorsType, typename CoeffsType>
00103 struct hseq_side_dependent_impl<VectorsType, CoeffsType, OnTheRight>
00104 {
00105   typedef Transpose<Block<const VectorsType, 1, Dynamic> > EssentialVectorType;
00106   typedef HouseholderSequence<VectorsType, CoeffsType, OnTheRight> HouseholderSequenceType;
00107   typedef typename VectorsType::Index Index;
00108   static inline const EssentialVectorType essentialVector(const HouseholderSequenceType& h, Index k)
00109   {
00110     Index start = k+1+h.m_shift;
00111     return Block<const VectorsType,1,Dynamic>(h.m_vectors, k, start, 1, h.rows()-start).transpose();
00112   }
00113 };
00114 
00115 template<typename OtherScalarType, typename MatrixType> struct matrix_type_times_scalar_type
00116 {
00117   typedef typename scalar_product_traits<OtherScalarType, typename MatrixType::Scalar>::ReturnType
00118     ResultScalar;
00119   typedef Matrix<ResultScalar, MatrixType::RowsAtCompileTime, MatrixType::ColsAtCompileTime,
00120                  0, MatrixType::MaxRowsAtCompileTime, MatrixType::MaxColsAtCompileTime> Type;
00121 };
00122 
00123 } // end namespace internal
00124 
00125 template<typename VectorsType, typename CoeffsType, int Side> class HouseholderSequence
00126   : public EigenBase<HouseholderSequence<VectorsType,CoeffsType,Side> >
00127 {
00128     enum {
00129       RowsAtCompileTime = internal::traits<HouseholderSequence>::RowsAtCompileTime,
00130       ColsAtCompileTime = internal::traits<HouseholderSequence>::ColsAtCompileTime,
00131       MaxRowsAtCompileTime = internal::traits<HouseholderSequence>::MaxRowsAtCompileTime,
00132       MaxColsAtCompileTime = internal::traits<HouseholderSequence>::MaxColsAtCompileTime
00133     };
00134     typedef typename internal::traits<HouseholderSequence>::Scalar Scalar;
00135     typedef typename VectorsType::Index Index;
00136 
00137     typedef typename internal::hseq_side_dependent_impl<VectorsType,CoeffsType,Side>::EssentialVectorType
00138             EssentialVectorType;
00139 
00140   public:
00141 
00142     typedef HouseholderSequence<
00143       VectorsType,
00144       typename internal::conditional<NumTraits<Scalar>::IsComplex,
00145         typename internal::remove_all<typename CoeffsType::ConjugateReturnType>::type,
00146         CoeffsType>::type,
00147       Side
00148     > ConjugateReturnType;
00149 
00167     HouseholderSequence(const VectorsType& v, const CoeffsType& h)
00168       : m_vectors(v), m_coeffs(h), m_trans(false), m_length(v.diagonalSize()),
00169         m_shift(0)
00170     {
00171     }
00172 
00174     HouseholderSequence(const HouseholderSequence& other)
00175       : m_vectors(other.m_vectors),
00176         m_coeffs(other.m_coeffs),
00177         m_trans(other.m_trans),
00178         m_length(other.m_length),
00179         m_shift(other.m_shift)
00180     {
00181     }
00182 
00187     Index rows() const { return Side==OnTheLeft ? m_vectors.rows() : m_vectors.cols(); }
00188 
00193     Index cols() const { return rows(); }
00194 
00209     const EssentialVectorType essentialVector(Index k) const
00210     {
00211       eigen_assert(k >= 0 && k < m_length);
00212       return internal::hseq_side_dependent_impl<VectorsType,CoeffsType,Side>::essentialVector(*this, k);
00213     }
00214 
00216     HouseholderSequence transpose() const
00217     {
00218       return HouseholderSequence(*this).setTrans(!m_trans);
00219     }
00220 
00222     ConjugateReturnType conjugate() const
00223     {
00224       return ConjugateReturnType(m_vectors, m_coeffs.conjugate())
00225              .setTrans(m_trans)
00226              .setLength(m_length)
00227              .setShift(m_shift);
00228     }
00229 
00231     ConjugateReturnType adjoint() const
00232     {
00233       return conjugate().setTrans(!m_trans);
00234     }
00235 
00237     ConjugateReturnType inverse() const { return adjoint(); }
00238 
00240     template<typename DestType> void evalTo(DestType& dst) const
00241     {
00242       Index vecs = m_length;
00243       // FIXME find a way to pass this temporary if the user wants to
00244       Matrix<Scalar, DestType::RowsAtCompileTime, 1,
00245              AutoAlign|ColMajor, DestType::MaxRowsAtCompileTime, 1> temp(rows());
00246       if(    internal::is_same<typename internal::remove_all<VectorsType>::type,DestType>::value
00247           && internal::extract_data(dst) == internal::extract_data(m_vectors))
00248       {
00249         // in-place
00250         dst.diagonal().setOnes();
00251         dst.template triangularView<StrictlyUpper>().setZero();
00252         for(Index k = vecs-1; k >= 0; --k)
00253         {
00254           Index cornerSize = rows() - k - m_shift;
00255           if(m_trans)
00256             dst.bottomRightCorner(cornerSize, cornerSize)
00257             .applyHouseholderOnTheRight(essentialVector(k), m_coeffs.coeff(k), &temp.coeffRef(0));
00258           else
00259             dst.bottomRightCorner(cornerSize, cornerSize)
00260               .applyHouseholderOnTheLeft(essentialVector(k), m_coeffs.coeff(k), &temp.coeffRef(0));
00261 
00262           // clear the off diagonal vector
00263           dst.col(k).tail(rows()-k-1).setZero();
00264         }
00265         // clear the remaining columns if needed
00266         for(Index k = 0; k<cols()-vecs ; ++k)
00267           dst.col(k).tail(rows()-k-1).setZero();
00268       }
00269       else
00270       {
00271         dst.setIdentity(rows(), rows());
00272         for(Index k = vecs-1; k >= 0; --k)
00273         {
00274           Index cornerSize = rows() - k - m_shift;
00275           if(m_trans)
00276             dst.bottomRightCorner(cornerSize, cornerSize)
00277             .applyHouseholderOnTheRight(essentialVector(k), m_coeffs.coeff(k), &temp.coeffRef(0));
00278           else
00279             dst.bottomRightCorner(cornerSize, cornerSize)
00280               .applyHouseholderOnTheLeft(essentialVector(k), m_coeffs.coeff(k), &temp.coeffRef(0));
00281         }
00282       }
00283     }
00284 
00286     template<typename Dest> inline void applyThisOnTheRight(Dest& dst) const
00287     {
00288       Matrix<Scalar,1,Dest::RowsAtCompileTime> temp(dst.rows());
00289       for(Index k = 0; k < m_length; ++k)
00290       {
00291         Index actual_k = m_trans ? m_length-k-1 : k;
00292         dst.rightCols(rows()-m_shift-actual_k)
00293            .applyHouseholderOnTheRight(essentialVector(actual_k), m_coeffs.coeff(actual_k), &temp.coeffRef(0));
00294       }
00295     }
00296 
00298     template<typename Dest> inline void applyThisOnTheLeft(Dest& dst) const
00299     {
00300       Matrix<Scalar,1,Dest::ColsAtCompileTime> temp(dst.cols());
00301       for(Index k = 0; k < m_length; ++k)
00302       {
00303         Index actual_k = m_trans ? k : m_length-k-1;
00304         dst.bottomRows(rows()-m_shift-actual_k)
00305            .applyHouseholderOnTheLeft(essentialVector(actual_k), m_coeffs.coeff(actual_k), &temp.coeffRef(0));
00306       }
00307     }
00308 
00316     template<typename OtherDerived>
00317     typename internal::matrix_type_times_scalar_type<Scalar, OtherDerived>::Type operator*(const MatrixBase<OtherDerived>& other) const
00318     {
00319       typename internal::matrix_type_times_scalar_type<Scalar, OtherDerived>::Type
00320         res(other.template cast<typename internal::matrix_type_times_scalar_type<Scalar,OtherDerived>::ResultScalar>());
00321       applyThisOnTheLeft(res);
00322       return res;
00323     }
00324 
00325     template<typename _VectorsType, typename _CoeffsType, int _Side> friend struct internal::hseq_side_dependent_impl;
00326 
00336     HouseholderSequence& setLength(Index length)
00337     {
00338       m_length = length;
00339       return *this;
00340     }
00341 
00353     HouseholderSequence& setShift(Index shift)
00354     {
00355       m_shift = shift;
00356       return *this;
00357     }
00358 
00359     Index length() const { return m_length; }  
00360     Index shift() const { return m_shift; }    
00362     /* Necessary for .adjoint() and .conjugate() */
00363     template <typename VectorsType2, typename CoeffsType2, int Side2> friend class HouseholderSequence;
00364 
00365   protected:
00366 
00375     HouseholderSequence& setTrans(bool trans)
00376     {
00377       m_trans = trans;
00378       return *this;
00379     }
00380 
00381     bool trans() const { return m_trans; }     
00383     typename VectorsType::Nested m_vectors;
00384     typename CoeffsType::Nested m_coeffs;
00385     bool m_trans;
00386     Index m_length;
00387     Index m_shift;
00388 };
00389 
00398 template<typename OtherDerived, typename VectorsType, typename CoeffsType, int Side>
00399 typename internal::matrix_type_times_scalar_type<typename VectorsType::Scalar,OtherDerived>::Type operator*(const MatrixBase<OtherDerived>& other, const HouseholderSequence<VectorsType,CoeffsType,Side>& h)
00400 {
00401   typename internal::matrix_type_times_scalar_type<typename VectorsType::Scalar,OtherDerived>::Type
00402     res(other.template cast<typename internal::matrix_type_times_scalar_type<typename VectorsType::Scalar,OtherDerived>::ResultScalar>());
00403   h.applyThisOnTheRight(res);
00404   return res;
00405 }
00406 
00411 template<typename VectorsType, typename CoeffsType>
00412 HouseholderSequence<VectorsType,CoeffsType> householderSequence(const VectorsType& v, const CoeffsType& h)
00413 {
00414   return HouseholderSequence<VectorsType,CoeffsType,OnTheLeft>(v, h);
00415 }
00416 
00423 template<typename VectorsType, typename CoeffsType>
00424 HouseholderSequence<VectorsType,CoeffsType,OnTheRight> rightHouseholderSequence(const VectorsType& v, const CoeffsType& h)
00425 {
00426   return HouseholderSequence<VectorsType,CoeffsType,OnTheRight>(v, h);
00427 }
00428 
00429 #endif // EIGEN_HOUSEHOLDER_SEQUENCE_H


libicr
Author(s): Robert Krug
autogenerated on Mon Jan 6 2014 11:32:48