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			318 lines
		
	
	
		
			10 KiB
		
	
	
	
		
			Plaintext
		
	
	
	
	
	
|   | // | ||
|  | //  Copyright (c) 2009 | ||
|  | //  Gunter Winkler | ||
|  | // | ||
|  | //  Distributed under the Boost Software License, Version 1.0. (See | ||
|  | //  accompanying file LICENSE_1_0.txt or copy at | ||
|  | //  http://www.boost.org/LICENSE_1_0.txt) | ||
|  | // | ||
|  | // | ||
|  | 
 | ||
|  | #ifndef _BOOST_UBLAS_SPARSE_VIEW_ | ||
|  | #define _BOOST_UBLAS_SPARSE_VIEW_ | ||
|  | 
 | ||
|  | #include <boost/numeric/ublas/matrix_expression.hpp> | ||
|  | #include <boost/numeric/ublas/detail/matrix_assign.hpp> | ||
|  | #if BOOST_UBLAS_TYPE_CHECK | ||
|  | #include <boost/numeric/ublas/matrix.hpp> | ||
|  | #endif | ||
|  | 
 | ||
|  | #include <boost/next_prior.hpp> | ||
|  | #include <boost/type_traits/remove_cv.hpp> | ||
|  | #include <boost/numeric/ublas/storage.hpp> | ||
|  | 
 | ||
|  | namespace boost { namespace numeric { namespace ublas { | ||
|  | 
 | ||
|  |     // view a chunk of memory as ublas array | ||
|  | 
 | ||
|  |     template < class T > | ||
|  |     class c_array_view | ||
|  |         : public storage_array< c_array_view<T> > { | ||
|  |     private: | ||
|  |         typedef c_array_view<T> self_type; | ||
|  |         typedef T * pointer; | ||
|  | 
 | ||
|  |     public: | ||
|  |         // TODO: think about a const pointer | ||
|  |         typedef const pointer array_type; | ||
|  | 
 | ||
|  |         typedef std::size_t size_type; | ||
|  |         typedef std::ptrdiff_t difference_type; | ||
|  | 
 | ||
|  |         typedef T value_type; | ||
|  |         typedef const T  &const_reference; | ||
|  |         typedef const T  *const_pointer; | ||
|  | 
 | ||
|  |         typedef const_pointer const_iterator; | ||
|  |         typedef std::reverse_iterator<const_iterator> const_reverse_iterator; | ||
|  | 
 | ||
|  |         // | ||
|  |         // typedefs required by vector concept | ||
|  |         // | ||
|  | 
 | ||
|  |         typedef dense_tag  storage_category; | ||
|  |         typedef const vector_reference<const self_type>    const_closure_type; | ||
|  | 
 | ||
|  |         c_array_view(size_type size, array_type data) : | ||
|  |             size_(size), data_(data) | ||
|  |         {} | ||
|  | 
 | ||
|  |         ~c_array_view() | ||
|  |         {} | ||
|  | 
 | ||
|  |         // | ||
|  |         // immutable methods of container concept | ||
|  |         // | ||
|  | 
 | ||
|  |         BOOST_UBLAS_INLINE | ||
|  |         size_type size () const { | ||
|  |             return size_; | ||
|  |         } | ||
|  | 
 | ||
|  |         BOOST_UBLAS_INLINE | ||
|  |         const_reference operator [] (size_type i) const { | ||
|  |             BOOST_UBLAS_CHECK (i < size_, bad_index ()); | ||
|  |             return data_ [i]; | ||
|  |         } | ||
|  | 
 | ||
|  |         BOOST_UBLAS_INLINE | ||
|  |         const_iterator begin () const { | ||
|  |             return data_; | ||
|  |         } | ||
|  |         BOOST_UBLAS_INLINE | ||
|  |         const_iterator end () const { | ||
|  |             return data_ + size_; | ||
|  |         } | ||
|  | 
 | ||
|  |         BOOST_UBLAS_INLINE | ||
|  |         const_reverse_iterator rbegin () const { | ||
|  |             return const_reverse_iterator (end ()); | ||
|  |         } | ||
|  |         BOOST_UBLAS_INLINE | ||
|  |         const_reverse_iterator rend () const { | ||
|  |             return const_reverse_iterator (begin ()); | ||
|  |         } | ||
|  | 
 | ||
|  |     private: | ||
|  |         size_type  size_; | ||
|  |         array_type data_; | ||
|  |     }; | ||
|  | 
 | ||
|  | 
 | ||
|  |     /** \brief Present existing arrays as compressed array based | ||
|  |      *  sparse matrix. | ||
|  |      *  This class provides CRS / CCS storage layout. | ||
|  |      * | ||
|  |      *  see also http://www.netlib.org/utk/papers/templates/node90.html | ||
|  |      * | ||
|  |      *       \param L layout type, either row_major or column_major | ||
|  |      *       \param IB index base, use 0 for C indexing and 1 for | ||
|  |      *       FORTRAN indexing of the internal index arrays. This | ||
|  |      *       does not affect the operator()(int,int) where the first | ||
|  |      *       row/column has always index 0. | ||
|  |      *       \param IA index array type, e.g., int[] | ||
|  |      *       \param TA value array type, e.g., double[] | ||
|  |      */ | ||
|  |     template<class L, std::size_t IB, class IA, class JA, class TA> | ||
|  |     class compressed_matrix_view: | ||
|  |         public matrix_expression<compressed_matrix_view<L, IB, IA, JA, TA> > { | ||
|  | 
 | ||
|  |     public: | ||
|  |         typedef typename vector_view_traits<TA>::value_type value_type; | ||
|  | 
 | ||
|  |     private: | ||
|  |         typedef value_type &true_reference; | ||
|  |         typedef value_type *pointer; | ||
|  |         typedef const value_type *const_pointer; | ||
|  |         typedef L layout_type; | ||
|  |         typedef compressed_matrix_view<L, IB, IA, JA, TA> self_type; | ||
|  | 
 | ||
|  |     public: | ||
|  | #ifdef BOOST_UBLAS_ENABLE_PROXY_SHORTCUTS | ||
|  |         using matrix_expression<self_type>::operator (); | ||
|  | #endif | ||
|  |         // ISSUE require type consistency check | ||
|  |         // is_convertable (IA::size_type, TA::size_type) | ||
|  |         typedef typename boost::remove_cv<typename vector_view_traits<JA>::value_type>::type index_type; | ||
|  |         // for compatibility, should be removed some day ... | ||
|  |         typedef index_type size_type; | ||
|  |         // size_type for the data arrays. | ||
|  |         typedef typename vector_view_traits<JA>::size_type array_size_type; | ||
|  |         typedef typename vector_view_traits<JA>::difference_type difference_type; | ||
|  |         typedef const value_type & const_reference; | ||
|  | 
 | ||
|  |         // do NOT define reference type, because class is read only | ||
|  |         // typedef value_type & reference; | ||
|  | 
 | ||
|  |         typedef IA rowptr_array_type; | ||
|  |         typedef JA index_array_type; | ||
|  |         typedef TA value_array_type; | ||
|  |         typedef const matrix_reference<const self_type> const_closure_type; | ||
|  |         typedef matrix_reference<self_type> closure_type; | ||
|  | 
 | ||
|  |         // FIXME: define a corresponding temporary type | ||
|  |         // typedef compressed_vector<T, IB, IA, TA> vector_temporary_type; | ||
|  | 
 | ||
|  |         // FIXME: define a corresponding temporary type | ||
|  |         // typedef self_type matrix_temporary_type; | ||
|  | 
 | ||
|  |         typedef sparse_tag storage_category; | ||
|  |         typedef typename L::orientation_category orientation_category; | ||
|  | 
 | ||
|  |         // | ||
|  |         // private types for internal use | ||
|  |         // | ||
|  | 
 | ||
|  |     private: | ||
|  |         typedef typename vector_view_traits<index_array_type>::const_iterator const_subiterator_type; | ||
|  | 
 | ||
|  |         // | ||
|  |         // Construction and destruction | ||
|  |         // | ||
|  |     private: | ||
|  |         /// private default constructor because data must be filled by caller | ||
|  |         BOOST_UBLAS_INLINE | ||
|  |         compressed_matrix_view () { } | ||
|  | 
 | ||
|  |     public: | ||
|  |         BOOST_UBLAS_INLINE | ||
|  |         compressed_matrix_view (index_type n_rows, index_type n_cols, array_size_type nnz | ||
|  |                                 , const rowptr_array_type & iptr | ||
|  |                                 , const index_array_type & jptr | ||
|  |                                 , const value_array_type & values): | ||
|  |             matrix_expression<self_type> (), | ||
|  |             size1_ (n_rows), size2_ (n_cols),  | ||
|  |             nnz_ (nnz), | ||
|  |             index1_data_ (iptr),  | ||
|  |             index2_data_ (jptr),  | ||
|  |             value_data_ (values) { | ||
|  |             storage_invariants (); | ||
|  |         } | ||
|  | 
 | ||
|  |         BOOST_UBLAS_INLINE | ||
|  |         compressed_matrix_view(const compressed_matrix_view& o) : | ||
|  |             size1_(o.size1_), size2_(o.size2_), | ||
|  |             nnz_(o.nnz_), | ||
|  |             index1_data_(o.index1_data_), | ||
|  |             index2_data_(o.index2_data_), | ||
|  |             value_data_(o.value_data_) | ||
|  |         {} | ||
|  | 
 | ||
|  |         // | ||
|  |         // implement immutable iterator types | ||
|  |         // | ||
|  | 
 | ||
|  |         class const_iterator1 {}; | ||
|  |         class const_iterator2 {}; | ||
|  | 
 | ||
|  |         typedef reverse_iterator_base1<const_iterator1> const_reverse_iterator1; | ||
|  |         typedef reverse_iterator_base2<const_iterator2> const_reverse_iterator2; | ||
|  | 
 | ||
|  |         // | ||
|  |         // implement all read only methods for the matrix expression concept | ||
|  |         //  | ||
|  | 
 | ||
|  |         //! return the number of rows  | ||
|  |         index_type size1() const { | ||
|  |             return size1_; | ||
|  |         } | ||
|  | 
 | ||
|  |         //! return the number of columns | ||
|  |         index_type size2() const { | ||
|  |             return size2_; | ||
|  |         } | ||
|  | 
 | ||
|  |         //! return value at position (i,j) | ||
|  |         value_type operator()(index_type i, index_type j) const { | ||
|  |             const_pointer p = find_element(i,j); | ||
|  |             if (!p) { | ||
|  |                 return zero_; | ||
|  |             } else { | ||
|  |                 return *p; | ||
|  |             } | ||
|  |         } | ||
|  |          | ||
|  | 
 | ||
|  |     private: | ||
|  |         // | ||
|  |         // private helper functions | ||
|  |         // | ||
|  | 
 | ||
|  |         const_pointer find_element (index_type i, index_type j) const { | ||
|  |             index_type element1 (layout_type::index_M (i, j)); | ||
|  |             index_type element2 (layout_type::index_m (i, j)); | ||
|  | 
 | ||
|  |             const array_size_type itv      = zero_based( index1_data_[element1] ); | ||
|  |             const array_size_type itv_next = zero_based( index1_data_[element1+1] ); | ||
|  | 
 | ||
|  |             const_subiterator_type it_start = boost::next(vector_view_traits<index_array_type>::begin(index2_data_),itv); | ||
|  |             const_subiterator_type it_end = boost::next(vector_view_traits<index_array_type>::begin(index2_data_),itv_next); | ||
|  |             const_subiterator_type it = find_index_in_row(it_start, it_end, element2) ; | ||
|  |              | ||
|  |             if (it == it_end || *it != k_based (element2)) | ||
|  |                 return 0; | ||
|  |             return &value_data_ [it - vector_view_traits<index_array_type>::begin(index2_data_)]; | ||
|  |         } | ||
|  | 
 | ||
|  |         const_subiterator_type find_index_in_row(const_subiterator_type it_start | ||
|  |                                                  , const_subiterator_type it_end | ||
|  |                                                  , index_type index) const { | ||
|  |             return std::lower_bound( it_start | ||
|  |                                      , it_end | ||
|  |                                      , k_based (index) ); | ||
|  |         } | ||
|  | 
 | ||
|  | 
 | ||
|  |     private: | ||
|  |         void storage_invariants () const { | ||
|  |             BOOST_UBLAS_CHECK (index1_data_ [layout_type::size_M (size1_, size2_)] == k_based (nnz_), external_logic ()); | ||
|  |         } | ||
|  |          | ||
|  |         index_type size1_; | ||
|  |         index_type size2_; | ||
|  | 
 | ||
|  |         array_size_type nnz_; | ||
|  | 
 | ||
|  |         const rowptr_array_type & index1_data_; | ||
|  |         const index_array_type & index2_data_; | ||
|  |         const value_array_type & value_data_; | ||
|  | 
 | ||
|  |         static const value_type zero_; | ||
|  | 
 | ||
|  |         BOOST_UBLAS_INLINE | ||
|  |         static index_type zero_based (index_type k_based_index) { | ||
|  |             return k_based_index - IB; | ||
|  |         } | ||
|  |         BOOST_UBLAS_INLINE | ||
|  |         static index_type k_based (index_type zero_based_index) { | ||
|  |             return zero_based_index + IB; | ||
|  |         } | ||
|  | 
 | ||
|  |         friend class iterator1; | ||
|  |         friend class iterator2; | ||
|  |         friend class const_iterator1; | ||
|  |         friend class const_iterator2; | ||
|  |     }; | ||
|  | 
 | ||
|  |     template<class L, std::size_t IB, class IA, class JA, class TA  > | ||
|  |     const typename compressed_matrix_view<L,IB,IA,JA,TA>::value_type  | ||
|  |     compressed_matrix_view<L,IB,IA,JA,TA>::zero_ = value_type/*zero*/(); | ||
|  | 
 | ||
|  | 
 | ||
|  |     template<class L, std::size_t IB, class IA, class JA, class TA  > | ||
|  |     compressed_matrix_view<L,IB,IA,JA,TA> | ||
|  |     make_compressed_matrix_view(typename vector_view_traits<JA>::value_type n_rows | ||
|  |                                 , typename vector_view_traits<JA>::value_type n_cols | ||
|  |                                 , typename vector_view_traits<JA>::size_type nnz | ||
|  |                                 , const IA & ia | ||
|  |                                 , const JA & ja | ||
|  |                                 , const TA & ta) { | ||
|  | 
 | ||
|  |         return compressed_matrix_view<L,IB,IA,JA,TA>(n_rows, n_cols, nnz, ia, ja, ta); | ||
|  | 
 | ||
|  |     } | ||
|  | 
 | ||
|  | }}} | ||
|  | 
 | ||
|  | #endif |