Ticket #7337: sparse_view.hpp

File sparse_view.hpp, 10.2 KB (added by Marco Guazzone <marco.guazzone@…>, 10 years ago)

The sparse_view.hpp}} resulting after applying patch {{{sparse_view-201209061016.

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