1 // 2 // Copyright (c) 2009 3 // Gunter Winkler 4 // 5 // Distributed under the Boost Software License, Version 1.0. (See 6 // accompanying file LICENSE_1_0.txt or copy at 7 // http://www.boost.org/LICENSE_1_0.txt) 8 // 9 // 10 11 #ifndef _BOOST_UBLAS_SPARSE_VIEW_ 12 #define _BOOST_UBLAS_SPARSE_VIEW_ 13 14 #include <boost/numeric/ublas/matrix_expression.hpp> 15 #include <boost/numeric/ublas/detail/matrix_assign.hpp> 16 #if BOOST_UBLAS_TYPE_CHECK 17 #include <boost/numeric/ublas/matrix.hpp> 18 #endif 19 20 #include <boost/next_prior.hpp> 21 #include <boost/type_traits/remove_cv.hpp> 22 #include <boost/numeric/ublas/storage.hpp> 23 24 namespace boost { namespace numeric { namespace ublas { 25 26 // view a chunk of memory as ublas array 27 28 template < class T > 29 class c_array_view 30 : public storage_array< c_array_view<T> > { 31 private: 32 typedef c_array_view<T> self_type; 33 typedef T * pointer; 34 35 public: 36 // TODO: think about a const pointer 37 typedef const pointer array_type; 38 39 typedef std::size_t size_type; 40 typedef std::ptrdiff_t difference_type; 41 42 typedef T value_type; 43 typedef const T &const_reference; 44 typedef const T *const_pointer; 45 46 typedef const_pointer const_iterator; 47 typedef std::reverse_iterator<const_iterator> const_reverse_iterator; 48 49 // 50 // typedefs required by vector concept 51 // 52 53 typedef dense_tag storage_category; 54 typedef const vector_reference<const self_type> const_closure_type; 55 c_array_view(size_type size,array_type data)56 c_array_view(size_type size, array_type data) : 57 size_(size), data_(data) 58 {} 59 ~c_array_view()60 ~c_array_view() 61 {} 62 63 // 64 // immutable methods of container concept 65 // 66 67 BOOST_UBLAS_INLINE size() const68 size_type size () const { 69 return size_; 70 } 71 72 BOOST_UBLAS_INLINE operator [](size_type i) const73 const_reference operator [] (size_type i) const { 74 BOOST_UBLAS_CHECK (i < size_, bad_index ()); 75 return data_ [i]; 76 } 77 78 BOOST_UBLAS_INLINE begin() const79 const_iterator begin () const { 80 return data_; 81 } 82 BOOST_UBLAS_INLINE end() const83 const_iterator end () const { 84 return data_ + size_; 85 } 86 87 BOOST_UBLAS_INLINE rbegin() const88 const_reverse_iterator rbegin () const { 89 return const_reverse_iterator (end ()); 90 } 91 BOOST_UBLAS_INLINE rend() const92 const_reverse_iterator rend () const { 93 return const_reverse_iterator (begin ()); 94 } 95 96 private: 97 size_type size_; 98 array_type data_; 99 }; 100 101 102 /** \brief Present existing arrays as compressed array based 103 * sparse matrix. 104 * This class provides CRS / CCS storage layout. 105 * 106 * see also http://www.netlib.org/utk/papers/templates/node90.html 107 * 108 * \param L layout type, either row_major or column_major 109 * \param IB index base, use 0 for C indexing and 1 for 110 * FORTRAN indexing of the internal index arrays. This 111 * does not affect the operator()(int,int) where the first 112 * row/column has always index 0. 113 * \param IA index array type, e.g., int[] 114 * \param TA value array type, e.g., double[] 115 */ 116 template<class L, std::size_t IB, class IA, class JA, class TA> 117 class compressed_matrix_view: 118 public matrix_expression<compressed_matrix_view<L, IB, IA, JA, TA> > { 119 120 public: 121 typedef typename vector_view_traits<TA>::value_type value_type; 122 123 private: 124 typedef value_type &true_reference; 125 typedef value_type *pointer; 126 typedef const value_type *const_pointer; 127 typedef L layout_type; 128 typedef compressed_matrix_view<L, IB, IA, JA, TA> self_type; 129 130 public: 131 #ifdef BOOST_UBLAS_ENABLE_PROXY_SHORTCUTS 132 using matrix_expression<self_type>::operator (); 133 #endif 134 // ISSUE require type consistency check 135 // is_convertable (IA::size_type, TA::size_type) 136 typedef typename boost::remove_cv<typename vector_view_traits<JA>::value_type>::type index_type; 137 // for compatibility, should be removed some day ... 138 typedef index_type size_type; 139 // size_type for the data arrays. 140 typedef typename vector_view_traits<JA>::size_type array_size_type; 141 typedef typename vector_view_traits<JA>::difference_type difference_type; 142 typedef const value_type & const_reference; 143 144 // do NOT define reference type, because class is read only 145 // typedef value_type & reference; 146 147 typedef IA rowptr_array_type; 148 typedef JA index_array_type; 149 typedef TA value_array_type; 150 typedef const matrix_reference<const self_type> const_closure_type; 151 typedef matrix_reference<self_type> closure_type; 152 153 // FIXME: define a corresponding temporary type 154 // typedef compressed_vector<T, IB, IA, TA> vector_temporary_type; 155 156 // FIXME: define a corresponding temporary type 157 // typedef self_type matrix_temporary_type; 158 159 typedef sparse_tag storage_category; 160 typedef typename L::orientation_category orientation_category; 161 162 // 163 // private types for internal use 164 // 165 166 private: 167 typedef typename vector_view_traits<index_array_type>::const_iterator const_subiterator_type; 168 169 // 170 // Construction and destruction 171 // 172 private: 173 /// private default constructor because data must be filled by caller 174 BOOST_UBLAS_INLINE compressed_matrix_view()175 compressed_matrix_view () { } 176 177 public: 178 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)179 compressed_matrix_view (index_type n_rows, index_type n_cols, array_size_type nnz 180 , const rowptr_array_type & iptr 181 , const index_array_type & jptr 182 , const value_array_type & values): 183 matrix_expression<self_type> (), 184 size1_ (n_rows), size2_ (n_cols), 185 nnz_ (nnz), 186 index1_data_ (iptr), 187 index2_data_ (jptr), 188 value_data_ (values) { 189 storage_invariants (); 190 } 191 192 BOOST_UBLAS_INLINE compressed_matrix_view(const compressed_matrix_view & o)193 compressed_matrix_view(const compressed_matrix_view& o) : 194 size1_(o.size1_), size2_(o.size2_), 195 nnz_(o.nnz_), 196 index1_data_(o.index1_data_), 197 index2_data_(o.index2_data_), 198 value_data_(o.value_data_) 199 {} 200 201 // 202 // implement immutable iterator types 203 // 204 205 class const_iterator1 {}; 206 class const_iterator2 {}; 207 208 typedef reverse_iterator_base1<const_iterator1> const_reverse_iterator1; 209 typedef reverse_iterator_base2<const_iterator2> const_reverse_iterator2; 210 211 // 212 // implement all read only methods for the matrix expression concept 213 // 214 215 //! return the number of rows size1() const216 index_type size1() const { 217 return size1_; 218 } 219 220 //! return the number of columns size2() const221 index_type size2() const { 222 return size2_; 223 } 224 225 //! return value at position (i,j) operator ()(index_type i,index_type j) const226 value_type operator()(index_type i, index_type j) const { 227 const_pointer p = find_element(i,j); 228 if (!p) { 229 return zero_; 230 } else { 231 return *p; 232 } 233 } 234 235 236 private: 237 // 238 // private helper functions 239 // 240 find_element(index_type i,index_type j) const241 const_pointer find_element (index_type i, index_type j) const { 242 index_type element1 (layout_type::index_M (i, j)); 243 index_type element2 (layout_type::index_m (i, j)); 244 245 const array_size_type itv = zero_based( index1_data_[element1] ); 246 const array_size_type itv_next = zero_based( index1_data_[element1+1] ); 247 248 const_subiterator_type it_start = boost::next(vector_view_traits<index_array_type>::begin(index2_data_),itv); 249 const_subiterator_type it_end = boost::next(vector_view_traits<index_array_type>::begin(index2_data_),itv_next); 250 const_subiterator_type it = find_index_in_row(it_start, it_end, element2) ; 251 252 if (it == it_end || *it != k_based (element2)) 253 return 0; 254 return &value_data_ [it - vector_view_traits<index_array_type>::begin(index2_data_)]; 255 } 256 find_index_in_row(const_subiterator_type it_start,const_subiterator_type it_end,index_type index) const257 const_subiterator_type find_index_in_row(const_subiterator_type it_start 258 , const_subiterator_type it_end 259 , index_type index) const { 260 return std::lower_bound( it_start 261 , it_end 262 , k_based (index) ); 263 } 264 265 266 private: storage_invariants() const267 void storage_invariants () const { 268 BOOST_UBLAS_CHECK (index1_data_ [layout_type::size_M (size1_, size2_)] == k_based (nnz_), external_logic ()); 269 } 270 271 index_type size1_; 272 index_type size2_; 273 274 array_size_type nnz_; 275 276 const rowptr_array_type & index1_data_; 277 const index_array_type & index2_data_; 278 const value_array_type & value_data_; 279 280 static const value_type zero_; 281 282 BOOST_UBLAS_INLINE zero_based(index_type k_based_index)283 static index_type zero_based (index_type k_based_index) { 284 return k_based_index - IB; 285 } 286 BOOST_UBLAS_INLINE k_based(index_type zero_based_index)287 static index_type k_based (index_type zero_based_index) { 288 return zero_based_index + IB; 289 } 290 291 friend class iterator1; 292 friend class iterator2; 293 friend class const_iterator1; 294 friend class const_iterator2; 295 }; 296 297 template<class L, std::size_t IB, class IA, class JA, class TA > 298 const typename compressed_matrix_view<L,IB,IA,JA,TA>::value_type 299 compressed_matrix_view<L,IB,IA,JA,TA>::zero_ = value_type/*zero*/(); 300 301 302 template<class L, std::size_t IB, class IA, class JA, class TA > 303 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)304 make_compressed_matrix_view(typename vector_view_traits<JA>::value_type n_rows 305 , typename vector_view_traits<JA>::value_type n_cols 306 , typename vector_view_traits<JA>::size_type nnz 307 , const IA & ia 308 , const JA & ja 309 , const TA & ta) { 310 311 return compressed_matrix_view<L,IB,IA,JA,TA>(n_rows, n_cols, nnz, ia, ja, ta); 312 313 } 314 315 }}} 316 317 #endif 318