| // This file is part of Eigen, a lightweight C++ template library |
| // for linear algebra. |
| // |
| // Copyright (C) 2013 Christian Seiler <christian@iwakd.de> |
| // |
| // 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 EIGEN_CXX11_TENSOR_TENSOR_H |
| #define EIGEN_CXX11_TENSOR_TENSOR_H |
| |
| namespace Eigen { |
| |
| /** \class Tensor |
| * \ingroup CXX11_Tensor_Module |
| * |
| * \brief The tensor class. |
| * |
| * The %Tensor class is the work-horse for all \em dense tensors within Eigen. |
| * |
| * The %Tensor class encompasses only dynamic-size objects so far. |
| * |
| * The first two template parameters are required: |
| * \tparam Scalar_ \anchor tensor_tparam_scalar Numeric type, e.g. float, double, int or std::complex<float>. |
| * User defined scalar types are supported as well (see \ref user_defined_scalars "here"). |
| * \tparam NumIndices_ Number of indices (i.e. rank of the tensor) |
| * |
| * The remaining template parameters are optional -- in most cases you don't have to worry about them. |
| * \tparam Options_ \anchor tensor_tparam_options A combination of either \b #RowMajor or \b #ColMajor, and of either |
| * \b #AutoAlign or \b #DontAlign. |
| * The former controls \ref TopicStorageOrders "storage order", and defaults to column-major. The latter controls alignment, which is required |
| * for vectorization. It defaults to aligning tensors. Note that tensors currently do not support any operations that profit from vectorization. |
| * Support for such operations (i.e. adding two tensors etc.) is planned. |
| * |
| * You can access elements of tensors using normal subscripting: |
| * |
| * \code |
| * Eigen::Tensor<double, 4> t(10, 10, 10, 10); |
| * t(0, 1, 2, 3) = 42.0; |
| * \endcode |
| * |
| * This class can be extended with the help of the plugin mechanism described on the page |
| * \ref TopicCustomizingEigen by defining the preprocessor symbol \c EIGEN_TENSOR_PLUGIN. |
| * |
| * <i><b>Some notes:</b></i> |
| * |
| * <dl> |
| * <dt><b>Relation to other parts of Eigen:</b></dt> |
| * <dd>The midterm developement goal for this class is to have a similar hierarchy as Eigen uses for matrices, so that |
| * taking blocks or using tensors in expressions is easily possible, including an interface with the vector/matrix code |
| * by providing .asMatrix() and .asVector() (or similar) methods for rank 2 and 1 tensors. However, currently, the %Tensor |
| * class does not provide any of these features and is only available as a stand-alone class that just allows for |
| * coefficient access. Also, when fixed-size tensors are implemented, the number of template arguments is likely to |
| * change dramatically.</dd> |
| * </dl> |
| * |
| * \ref TopicStorageOrders |
| */ |
| template<typename Scalar_, std::size_t NumIndices_, int Options_ = 0> |
| class Tensor; |
| |
| namespace internal { |
| template<typename Scalar_, std::size_t NumIndices_, int Options_> |
| struct traits<Tensor<Scalar_, NumIndices_, Options_>> |
| { |
| typedef Scalar_ Scalar; |
| typedef Dense StorageKind; |
| typedef DenseIndex Index; |
| enum { |
| Options = Options_ |
| }; |
| }; |
| |
| template<typename Index, std::size_t NumIndices, std::size_t n, bool RowMajor> |
| struct tensor_index_linearization_helper |
| { |
| constexpr static inline Index run(std::array<Index, NumIndices> const& indices, std::array<Index, NumIndices> const& dimensions) |
| { |
| return std_array_get<RowMajor ? n : (NumIndices - n - 1)>(indices) + |
| std_array_get<RowMajor ? n : (NumIndices - n - 1)>(dimensions) * |
| tensor_index_linearization_helper<Index, NumIndices, n - 1, RowMajor>::run(indices, dimensions); |
| } |
| }; |
| |
| template<typename Index, std::size_t NumIndices, bool RowMajor> |
| struct tensor_index_linearization_helper<Index, NumIndices, 0, RowMajor> |
| { |
| constexpr static inline Index run(std::array<Index, NumIndices> const& indices, std::array<Index, NumIndices> const&) |
| { |
| return std_array_get<RowMajor ? 0 : NumIndices - 1>(indices); |
| } |
| }; |
| } // end namespace internal |
| |
| template<typename Scalar_, std::size_t NumIndices_, int Options_> |
| class Tensor |
| { |
| static_assert(NumIndices_ >= 1, "A tensor must have at least one index."); |
| |
| public: |
| typedef Tensor<Scalar_, NumIndices_, Options_> Self; |
| typedef typename internal::traits<Self>::StorageKind StorageKind; |
| typedef typename internal::traits<Self>::Index Index; |
| typedef typename internal::traits<Self>::Scalar Scalar; |
| typedef typename internal::packet_traits<Scalar>::type PacketScalar; |
| typedef typename NumTraits<Scalar>::Real RealScalar; |
| typedef Self DenseType; |
| |
| constexpr static int Options = Options_; |
| constexpr static std::size_t NumIndices = NumIndices_; |
| |
| protected: |
| TensorStorage<Scalar, NumIndices, Dynamic, Options> m_storage; |
| |
| public: |
| EIGEN_STRONG_INLINE Index dimension(std::size_t n) const { return m_storage.dimensions()[n]; } |
| EIGEN_STRONG_INLINE std::array<Index, NumIndices> dimensions() const { return m_storage.dimensions(); } |
| EIGEN_STRONG_INLINE Index size() const { return internal::array_prod(m_storage.dimensions()); } |
| EIGEN_STRONG_INLINE Scalar *data() { return m_storage.data(); } |
| EIGEN_STRONG_INLINE const Scalar *data() const { return m_storage.data(); } |
| |
| // This makes EIGEN_INITIALIZE_COEFFS_IF_THAT_OPTION_IS_ENABLED |
| // work, because that uses base().coeffRef() - and we don't yet |
| // implement a similar class hierarchy |
| inline Self& base() { return *this; } |
| inline const Self& base() const { return *this; } |
| |
| void setZero() |
| { |
| // FIXME: until we have implemented packet access and the |
| // expression engine w.r.t. nullary ops, use this |
| // as a kludge. Only works with POD types, but for |
| // any standard usage, this shouldn't be a problem |
| memset((void *)data(), 0, size() * sizeof(Scalar)); |
| } |
| |
| inline Self& operator=(Self const& other) |
| { |
| m_storage = other.m_storage; |
| return *this; |
| } |
| |
| template<typename... IndexTypes> |
| inline const Scalar& coeff(Index firstIndex, Index secondIndex, IndexTypes... otherIndices) const |
| { |
| static_assert(sizeof...(otherIndices) + 2 == NumIndices, "Number of indices used to access a tensor coefficient must be equal to the rank of the tensor."); |
| return coeff(std::array<Index, NumIndices>{{firstIndex, secondIndex, otherIndices...}}); |
| } |
| |
| inline const Scalar& coeff(const std::array<Index, NumIndices>& indices) const |
| { |
| eigen_internal_assert(checkIndexRange(indices)); |
| return m_storage.data()[linearizedIndex(indices)]; |
| } |
| |
| inline const Scalar& coeff(Index index) const |
| { |
| eigen_internal_assert(index >= 0 && index < size()); |
| return m_storage.data()[index]; |
| } |
| |
| template<typename... IndexTypes> |
| inline Scalar& coeffRef(Index firstIndex, Index secondIndex, IndexTypes... otherIndices) |
| { |
| static_assert(sizeof...(otherIndices) + 2 == NumIndices, "Number of indices used to access a tensor coefficient must be equal to the rank of the tensor."); |
| return coeffRef(std::array<Index, NumIndices>{{firstIndex, secondIndex, otherIndices...}}); |
| } |
| |
| inline Scalar& coeffRef(const std::array<Index, NumIndices>& indices) |
| { |
| eigen_internal_assert(checkIndexRange(indices)); |
| return m_storage.data()[linearizedIndex(indices)]; |
| } |
| |
| inline Scalar& coeffRef(Index index) |
| { |
| eigen_internal_assert(index >= 0 && index < size()); |
| return m_storage.data()[index]; |
| } |
| |
| template<typename... IndexTypes> |
| inline const Scalar& operator()(Index firstIndex, Index secondIndex, IndexTypes... otherIndices) const |
| { |
| static_assert(sizeof...(otherIndices) + 2 == NumIndices, "Number of indices used to access a tensor coefficient must be equal to the rank of the tensor."); |
| return this->operator()(std::array<Index, NumIndices>{{firstIndex, secondIndex, otherIndices...}}); |
| } |
| |
| inline const Scalar& operator()(const std::array<Index, NumIndices>& indices) const |
| { |
| eigen_assert(checkIndexRange(indices)); |
| return coeff(indices); |
| } |
| |
| inline const Scalar& operator()(Index index) const |
| { |
| eigen_internal_assert(index >= 0 && index < size()); |
| return coeff(index); |
| } |
| |
| inline const Scalar& operator[](Index index) const |
| { |
| static_assert(NumIndices == 1, "The bracket operator is only for vectors, use the parenthesis operator instead."); |
| return coeff(index); |
| } |
| |
| template<typename... IndexTypes> |
| inline Scalar& operator()(Index firstIndex, Index secondIndex, IndexTypes... otherIndices) |
| { |
| static_assert(sizeof...(otherIndices) + 2 == NumIndices, "Number of indices used to access a tensor coefficient must be equal to the rank of the tensor."); |
| return operator()(std::array<Index, NumIndices>{{firstIndex, secondIndex, otherIndices...}}); |
| } |
| |
| inline Scalar& operator()(const std::array<Index, NumIndices>& indices) |
| { |
| eigen_assert(checkIndexRange(indices)); |
| return coeffRef(indices); |
| } |
| |
| inline Scalar& operator()(Index index) |
| { |
| eigen_assert(index >= 0 && index < size()); |
| return coeffRef(index); |
| } |
| |
| inline Scalar& operator[](Index index) |
| { |
| static_assert(NumIndices == 1, "The bracket operator is only for vectors, use the parenthesis operator instead."); |
| return coeffRef(index); |
| } |
| |
| inline Tensor() |
| : m_storage() |
| { |
| } |
| |
| inline Tensor(const Self& other) |
| : m_storage(other.m_storage) |
| { |
| } |
| |
| inline Tensor(Self&& other) |
| : m_storage(other.m_storage) |
| { |
| } |
| |
| template<typename... IndexTypes> |
| inline Tensor(Index firstDimension, IndexTypes... otherDimensions) |
| : m_storage() |
| { |
| static_assert(sizeof...(otherDimensions) + 1 == NumIndices, "Number of dimensions used to construct a tensor must be equal to the rank of the tensor."); |
| resize(std::array<Index, NumIndices>{{firstDimension, otherDimensions...}}); |
| } |
| |
| inline Tensor(std::array<Index, NumIndices> dimensions) |
| : m_storage(internal::array_prod(dimensions), dimensions) |
| { |
| EIGEN_INITIALIZE_COEFFS_IF_THAT_OPTION_IS_ENABLED |
| } |
| |
| template<typename... IndexTypes> |
| void resize(Index firstDimension, IndexTypes... otherDimensions) |
| { |
| static_assert(sizeof...(otherDimensions) + 1 == NumIndices, "Number of dimensions used to resize a tensor must be equal to the rank of the tensor."); |
| resize(std::array<Index, NumIndices>{{firstDimension, otherDimensions...}}); |
| } |
| |
| void resize(const std::array<Index, NumIndices>& dimensions) |
| { |
| std::size_t i; |
| Index size = Index(1); |
| for (i = 0; i < NumIndices; i++) { |
| internal::check_rows_cols_for_overflow<Dynamic>::run(size, dimensions[i]); |
| size *= dimensions[i]; |
| } |
| #ifdef EIGEN_INITIALIZE_COEFFS |
| bool size_changed = size != this->size(); |
| m_storage.resize(size, dimensions); |
| if(size_changed) EIGEN_INITIALIZE_COEFFS_IF_THAT_OPTION_IS_ENABLED |
| #else |
| m_storage.resize(size, dimensions); |
| #endif |
| } |
| |
| protected: |
| bool checkIndexRange(const std::array<Index, NumIndices>& indices) const |
| { |
| using internal::array_apply_and_reduce; |
| using internal::array_zip_and_reduce; |
| using internal::greater_equal_zero_op; |
| using internal::logical_and_op; |
| using internal::lesser_op; |
| |
| return |
| // check whether the indices are all >= 0 |
| array_apply_and_reduce<logical_and_op, greater_equal_zero_op>(indices) && |
| // check whether the indices fit in the dimensions |
| array_zip_and_reduce<logical_and_op, lesser_op>(indices, m_storage.dimensions()); |
| } |
| |
| inline Index linearizedIndex(const std::array<Index, NumIndices>& indices) const |
| { |
| return internal::tensor_index_linearization_helper<Index, NumIndices, NumIndices - 1, Options&RowMajor>::run(indices, m_storage.dimensions()); |
| } |
| }; |
| |
| } // end namespace Eigen |
| |
| #endif // EIGEN_CXX11_TENSOR_TENSOR_H |
| |
| /* |
| * kate: space-indent on; indent-width 2; mixedindent off; indent-mode cstyle; |
| */ |