| // This file is part of Eigen, a lightweight C++ template library |
| // for linear algebra. |
| // |
| // Copyright (C) 2011 Kolja Brix <brix@igpm.rwth-aachen.de> |
| // Copyright (C) 2011 Andreas Platen <andiplaten@gmx.de> |
| // Copyright (C) 2012 Chen-Pang He <jdh8@ms63.hinet.net> |
| // |
| // This Source Code Form is subject to the terms of the Mozilla |
| // Public License v. 2.0. If a copy of the MPL was not distributed |
| // with this file, You can obtain one at http://mozilla.org/MPL/2.0/. |
| |
| #ifndef KRONECKER_TENSOR_PRODUCT_H |
| #define KRONECKER_TENSOR_PRODUCT_H |
| |
| // IWYU pragma: private |
| #include "./InternalHeaderCheck.h" |
| |
| namespace Eigen { |
| |
| /*! |
| * \ingroup KroneckerProduct_Module |
| * |
| * \brief The base class of dense and sparse Kronecker product. |
| * |
| * \tparam Derived is the derived type. |
| */ |
| template <typename Derived> |
| class KroneckerProductBase : public ReturnByValue<Derived> { |
| private: |
| typedef typename internal::traits<Derived> Traits; |
| typedef typename Traits::Scalar Scalar; |
| |
| protected: |
| typedef typename Traits::Lhs Lhs; |
| typedef typename Traits::Rhs Rhs; |
| |
| public: |
| /*! \brief Constructor. */ |
| KroneckerProductBase(const Lhs& A, const Rhs& B) : m_A(A), m_B(B) {} |
| |
| inline Index rows() const { return m_A.rows() * m_B.rows(); } |
| inline Index cols() const { return m_A.cols() * m_B.cols(); } |
| |
| /*! |
| * This overrides ReturnByValue::coeff because this function is |
| * efficient enough. |
| */ |
| Scalar coeff(Index row, Index col) const { |
| return m_A.coeff(row / m_B.rows(), col / m_B.cols()) * m_B.coeff(row % m_B.rows(), col % m_B.cols()); |
| } |
| |
| /*! |
| * This overrides ReturnByValue::coeff because this function is |
| * efficient enough. |
| */ |
| Scalar coeff(Index i) const { |
| EIGEN_STATIC_ASSERT_VECTOR_ONLY(Derived); |
| return m_A.coeff(i / m_A.size()) * m_B.coeff(i % m_A.size()); |
| } |
| |
| protected: |
| typename Lhs::Nested m_A; |
| typename Rhs::Nested m_B; |
| }; |
| |
| /*! |
| * \ingroup KroneckerProduct_Module |
| * |
| * \brief Kronecker tensor product helper class for dense matrices |
| * |
| * This class is the return value of kroneckerProduct(MatrixBase, |
| * MatrixBase). Use the function rather than construct this class |
| * directly to avoid specifying template prarameters. |
| * |
| * \tparam Lhs Type of the left-hand side, a matrix expression. |
| * \tparam Rhs Type of the rignt-hand side, a matrix expression. |
| */ |
| template <typename Lhs, typename Rhs> |
| class KroneckerProduct : public KroneckerProductBase<KroneckerProduct<Lhs, Rhs> > { |
| private: |
| typedef KroneckerProductBase<KroneckerProduct> Base; |
| using Base::m_A; |
| using Base::m_B; |
| |
| public: |
| /*! \brief Constructor. */ |
| KroneckerProduct(const Lhs& A, const Rhs& B) : Base(A, B) {} |
| |
| /*! \brief Evaluate the Kronecker tensor product. */ |
| template <typename Dest> |
| void evalTo(Dest& dst) const; |
| }; |
| |
| /*! |
| * \ingroup KroneckerProduct_Module |
| * |
| * \brief Kronecker tensor product helper class for sparse matrices |
| * |
| * If at least one of the operands is a sparse matrix expression, |
| * then this class is returned and evaluates into a sparse matrix. |
| * |
| * This class is the return value of kroneckerProduct(EigenBase, |
| * EigenBase). Use the function rather than construct this class |
| * directly to avoid specifying template prarameters. |
| * |
| * \tparam Lhs Type of the left-hand side, a matrix expression. |
| * \tparam Rhs Type of the rignt-hand side, a matrix expression. |
| */ |
| template <typename Lhs, typename Rhs> |
| class KroneckerProductSparse : public KroneckerProductBase<KroneckerProductSparse<Lhs, Rhs> > { |
| private: |
| typedef KroneckerProductBase<KroneckerProductSparse> Base; |
| using Base::m_A; |
| using Base::m_B; |
| |
| public: |
| /*! \brief Constructor. */ |
| KroneckerProductSparse(const Lhs& A, const Rhs& B) : Base(A, B) {} |
| |
| /*! \brief Evaluate the Kronecker tensor product. */ |
| template <typename Dest> |
| void evalTo(Dest& dst) const; |
| }; |
| |
| template <typename Lhs, typename Rhs> |
| template <typename Dest> |
| void KroneckerProduct<Lhs, Rhs>::evalTo(Dest& dst) const { |
| const int BlockRows = Rhs::RowsAtCompileTime, BlockCols = Rhs::ColsAtCompileTime; |
| const Index Br = m_B.rows(), Bc = m_B.cols(); |
| for (Index i = 0; i < m_A.rows(); ++i) |
| for (Index j = 0; j < m_A.cols(); ++j) |
| Block<Dest, BlockRows, BlockCols>(dst, i * Br, j * Bc, Br, Bc) = m_A.coeff(i, j) * m_B; |
| } |
| |
| template <typename Lhs, typename Rhs> |
| template <typename Dest> |
| void KroneckerProductSparse<Lhs, Rhs>::evalTo(Dest& dst) const { |
| Index Br = m_B.rows(), Bc = m_B.cols(); |
| dst.resize(this->rows(), this->cols()); |
| dst.resizeNonZeros(0); |
| |
| // 1 - evaluate the operands if needed: |
| typedef typename internal::nested_eval<Lhs, Dynamic>::type Lhs1; |
| typedef internal::remove_all_t<Lhs1> Lhs1Cleaned; |
| const Lhs1 lhs1(m_A); |
| typedef typename internal::nested_eval<Rhs, Dynamic>::type Rhs1; |
| typedef internal::remove_all_t<Rhs1> Rhs1Cleaned; |
| const Rhs1 rhs1(m_B); |
| |
| // 2 - construct respective iterators |
| typedef Eigen::InnerIterator<Lhs1Cleaned> LhsInnerIterator; |
| typedef Eigen::InnerIterator<Rhs1Cleaned> RhsInnerIterator; |
| |
| // compute number of non-zeros per innervectors of dst |
| { |
| // TODO VectorXi is not necessarily big enough! |
| VectorXi nnzA = VectorXi::Zero(Dest::IsRowMajor ? m_A.rows() : m_A.cols()); |
| for (Index kA = 0; kA < m_A.outerSize(); ++kA) |
| for (LhsInnerIterator itA(lhs1, kA); itA; ++itA) nnzA(Dest::IsRowMajor ? itA.row() : itA.col())++; |
| |
| VectorXi nnzB = VectorXi::Zero(Dest::IsRowMajor ? m_B.rows() : m_B.cols()); |
| for (Index kB = 0; kB < m_B.outerSize(); ++kB) |
| for (RhsInnerIterator itB(rhs1, kB); itB; ++itB) nnzB(Dest::IsRowMajor ? itB.row() : itB.col())++; |
| |
| Matrix<int, Dynamic, Dynamic, ColMajor> nnzAB = nnzB * nnzA.transpose(); |
| dst.reserve(VectorXi::Map(nnzAB.data(), nnzAB.size())); |
| } |
| |
| for (Index kA = 0; kA < m_A.outerSize(); ++kA) { |
| for (Index kB = 0; kB < m_B.outerSize(); ++kB) { |
| for (LhsInnerIterator itA(lhs1, kA); itA; ++itA) { |
| for (RhsInnerIterator itB(rhs1, kB); itB; ++itB) { |
| Index i = itA.row() * Br + itB.row(), j = itA.col() * Bc + itB.col(); |
| dst.insert(i, j) = itA.value() * itB.value(); |
| } |
| } |
| } |
| } |
| } |
| |
| namespace internal { |
| |
| template <typename Lhs_, typename Rhs_> |
| struct traits<KroneckerProduct<Lhs_, Rhs_> > { |
| typedef remove_all_t<Lhs_> Lhs; |
| typedef remove_all_t<Rhs_> Rhs; |
| typedef typename ScalarBinaryOpTraits<typename Lhs::Scalar, typename Rhs::Scalar>::ReturnType Scalar; |
| typedef typename promote_index_type<typename Lhs::StorageIndex, typename Rhs::StorageIndex>::type StorageIndex; |
| |
| enum { |
| Rows = size_at_compile_time(traits<Lhs>::RowsAtCompileTime, traits<Rhs>::RowsAtCompileTime), |
| Cols = size_at_compile_time(traits<Lhs>::ColsAtCompileTime, traits<Rhs>::ColsAtCompileTime), |
| MaxRows = size_at_compile_time(traits<Lhs>::MaxRowsAtCompileTime, traits<Rhs>::MaxRowsAtCompileTime), |
| MaxCols = size_at_compile_time(traits<Lhs>::MaxColsAtCompileTime, traits<Rhs>::MaxColsAtCompileTime) |
| }; |
| |
| typedef Matrix<Scalar, Rows, Cols> ReturnType; |
| }; |
| |
| template <typename Lhs_, typename Rhs_> |
| struct traits<KroneckerProductSparse<Lhs_, Rhs_> > { |
| typedef MatrixXpr XprKind; |
| typedef remove_all_t<Lhs_> Lhs; |
| typedef remove_all_t<Rhs_> Rhs; |
| typedef typename ScalarBinaryOpTraits<typename Lhs::Scalar, typename Rhs::Scalar>::ReturnType Scalar; |
| typedef typename cwise_promote_storage_type<typename traits<Lhs>::StorageKind, typename traits<Rhs>::StorageKind, |
| scalar_product_op<typename Lhs::Scalar, typename Rhs::Scalar> >::ret |
| StorageKind; |
| typedef typename promote_index_type<typename Lhs::StorageIndex, typename Rhs::StorageIndex>::type StorageIndex; |
| |
| enum { |
| LhsFlags = Lhs::Flags, |
| RhsFlags = Rhs::Flags, |
| |
| RowsAtCompileTime = size_at_compile_time(traits<Lhs>::RowsAtCompileTime, traits<Rhs>::RowsAtCompileTime), |
| ColsAtCompileTime = size_at_compile_time(traits<Lhs>::ColsAtCompileTime, traits<Rhs>::ColsAtCompileTime), |
| MaxRowsAtCompileTime = size_at_compile_time(traits<Lhs>::MaxRowsAtCompileTime, traits<Rhs>::MaxRowsAtCompileTime), |
| MaxColsAtCompileTime = size_at_compile_time(traits<Lhs>::MaxColsAtCompileTime, traits<Rhs>::MaxColsAtCompileTime), |
| |
| EvalToRowMajor = (int(LhsFlags) & int(RhsFlags) & RowMajorBit), |
| RemovedBits = ~(EvalToRowMajor ? 0 : RowMajorBit), |
| |
| Flags = ((int(LhsFlags) | int(RhsFlags)) & HereditaryBits & RemovedBits) | EvalBeforeNestingBit, |
| CoeffReadCost = HugeCost |
| }; |
| |
| typedef SparseMatrix<Scalar, 0, StorageIndex> ReturnType; |
| }; |
| |
| } // end namespace internal |
| |
| /*! |
| * \ingroup KroneckerProduct_Module |
| * |
| * Computes Kronecker tensor product of two dense matrices |
| * |
| * \warning If you want to replace a matrix by its Kronecker product |
| * with some matrix, do \b NOT do this: |
| * \code |
| * A = kroneckerProduct(A,B); // bug!!! caused by aliasing effect |
| * \endcode |
| * instead, use eval() to work around this: |
| * \code |
| * A = kroneckerProduct(A,B).eval(); |
| * \endcode |
| * |
| * \param a Dense matrix a |
| * \param b Dense matrix b |
| * \return Kronecker tensor product of a and b |
| */ |
| template <typename A, typename B> |
| KroneckerProduct<A, B> kroneckerProduct(const MatrixBase<A>& a, const MatrixBase<B>& b) { |
| return KroneckerProduct<A, B>(a.derived(), b.derived()); |
| } |
| |
| /*! |
| * \ingroup KroneckerProduct_Module |
| * |
| * Computes Kronecker tensor product of two matrices, at least one of |
| * which is sparse |
| * |
| * \warning If you want to replace a matrix by its Kronecker product |
| * with some matrix, do \b NOT do this: |
| * \code |
| * A = kroneckerProduct(A,B); // bug!!! caused by aliasing effect |
| * \endcode |
| * instead, use eval() to work around this: |
| * \code |
| * A = kroneckerProduct(A,B).eval(); |
| * \endcode |
| * |
| * \param a Dense/sparse matrix a |
| * \param b Dense/sparse matrix b |
| * \return Kronecker tensor product of a and b, stored in a sparse |
| * matrix |
| */ |
| template <typename A, typename B> |
| KroneckerProductSparse<A, B> kroneckerProduct(const EigenBase<A>& a, const EigenBase<B>& b) { |
| return KroneckerProductSparse<A, B>(a.derived(), b.derived()); |
| } |
| |
| } // end namespace Eigen |
| |
| #endif // KRONECKER_TENSOR_PRODUCT_H |