Chris@16: //
Chris@16: //  Copyright (c) 2009
Chris@16: //  Gunter Winkler
Chris@16: //
Chris@16: //  Distributed under the Boost Software License, Version 1.0. (See
Chris@16: //  accompanying file LICENSE_1_0.txt or copy at
Chris@16: //  http://www.boost.org/LICENSE_1_0.txt)
Chris@16: //
Chris@16: //
Chris@16: 
Chris@16: #ifndef _BOOST_UBLAS_SPARSE_VIEW_
Chris@16: #define _BOOST_UBLAS_SPARSE_VIEW_
Chris@16: 
Chris@16: #include <boost/numeric/ublas/matrix_expression.hpp>
Chris@16: #include <boost/numeric/ublas/detail/matrix_assign.hpp>
Chris@16: #if BOOST_UBLAS_TYPE_CHECK
Chris@16: #include <boost/numeric/ublas/matrix.hpp>
Chris@16: #endif
Chris@16: 
Chris@16: #include <boost/next_prior.hpp>
Chris@16: #include <boost/type_traits/remove_cv.hpp>
Chris@101: #include <boost/numeric/ublas/storage.hpp>
Chris@16: 
Chris@16: namespace boost { namespace numeric { namespace ublas {
Chris@16: 
Chris@16:     // view a chunk of memory as ublas array
Chris@16: 
Chris@16:     template < class T >
Chris@16:     class c_array_view
Chris@16:         : public storage_array< c_array_view<T> > {
Chris@16:     private:
Chris@16:         typedef c_array_view<T> self_type;
Chris@16:         typedef T * pointer;
Chris@16: 
Chris@16:     public:
Chris@16:         // TODO: think about a const pointer
Chris@16:         typedef const pointer array_type;
Chris@16: 
Chris@16:         typedef std::size_t size_type;
Chris@16:         typedef std::ptrdiff_t difference_type;
Chris@16: 
Chris@16:         typedef T value_type;
Chris@16:         typedef const T  &const_reference;
Chris@16:         typedef const T  *const_pointer;
Chris@16: 
Chris@16:         typedef const_pointer const_iterator;
Chris@16:         typedef std::reverse_iterator<const_iterator> const_reverse_iterator;
Chris@16: 
Chris@16:         //
Chris@16:         // typedefs required by vector concept
Chris@16:         //
Chris@16: 
Chris@16:         typedef dense_tag  storage_category;
Chris@16:         typedef const vector_reference<const self_type>    const_closure_type;
Chris@16: 
Chris@16:         c_array_view(size_type size, array_type data) :
Chris@16:             size_(size), data_(data)
Chris@16:         {}
Chris@16: 
Chris@16:         ~c_array_view()
Chris@16:         {}
Chris@16: 
Chris@16:         //
Chris@16:         // immutable methods of container concept
Chris@16:         //
Chris@16: 
Chris@16:         BOOST_UBLAS_INLINE
Chris@16:         size_type size () const {
Chris@16:             return size_;
Chris@16:         }
Chris@16: 
Chris@16:         BOOST_UBLAS_INLINE
Chris@16:         const_reference operator [] (size_type i) const {
Chris@16:             BOOST_UBLAS_CHECK (i < size_, bad_index ());
Chris@16:             return data_ [i];
Chris@16:         }
Chris@16: 
Chris@16:         BOOST_UBLAS_INLINE
Chris@16:         const_iterator begin () const {
Chris@16:             return data_;
Chris@16:         }
Chris@16:         BOOST_UBLAS_INLINE
Chris@16:         const_iterator end () const {
Chris@16:             return data_ + size_;
Chris@16:         }
Chris@16: 
Chris@16:         BOOST_UBLAS_INLINE
Chris@16:         const_reverse_iterator rbegin () const {
Chris@16:             return const_reverse_iterator (end ());
Chris@16:         }
Chris@16:         BOOST_UBLAS_INLINE
Chris@16:         const_reverse_iterator rend () const {
Chris@16:             return const_reverse_iterator (begin ());
Chris@16:         }
Chris@16: 
Chris@16:     private:
Chris@16:         size_type  size_;
Chris@16:         array_type data_;
Chris@16:     };
Chris@16: 
Chris@16: 
Chris@16:     /** \brief Present existing arrays as compressed array based
Chris@16:      *  sparse matrix.
Chris@16:      *  This class provides CRS / CCS storage layout.
Chris@16:      *
Chris@16:      *  see also http://www.netlib.org/utk/papers/templates/node90.html
Chris@16:      *
Chris@16:      *       \param L layout type, either row_major or column_major
Chris@16:      *       \param IB index base, use 0 for C indexing and 1 for
Chris@16:      *       FORTRAN indexing of the internal index arrays. This
Chris@16:      *       does not affect the operator()(int,int) where the first
Chris@16:      *       row/column has always index 0.
Chris@16:      *       \param IA index array type, e.g., int[]
Chris@16:      *       \param TA value array type, e.g., double[]
Chris@16:      */
Chris@16:     template<class L, std::size_t IB, class IA, class JA, class TA>
Chris@16:     class compressed_matrix_view:
Chris@16:         public matrix_expression<compressed_matrix_view<L, IB, IA, JA, TA> > {
Chris@16: 
Chris@16:     public:
Chris@16:         typedef typename vector_view_traits<TA>::value_type value_type;
Chris@16: 
Chris@16:     private:
Chris@16:         typedef value_type &true_reference;
Chris@16:         typedef value_type *pointer;
Chris@16:         typedef const value_type *const_pointer;
Chris@16:         typedef L layout_type;
Chris@16:         typedef compressed_matrix_view<L, IB, IA, JA, TA> self_type;
Chris@16: 
Chris@16:     public:
Chris@16: #ifdef BOOST_UBLAS_ENABLE_PROXY_SHORTCUTS
Chris@16:         using matrix_expression<self_type>::operator ();
Chris@16: #endif
Chris@16:         // ISSUE require type consistency check
Chris@16:         // is_convertable (IA::size_type, TA::size_type)
Chris@16:         typedef typename boost::remove_cv<typename vector_view_traits<JA>::value_type>::type index_type;
Chris@16:         // for compatibility, should be removed some day ...
Chris@16:         typedef index_type size_type;
Chris@16:         // size_type for the data arrays.
Chris@16:         typedef typename vector_view_traits<JA>::size_type array_size_type;
Chris@16:         typedef typename vector_view_traits<JA>::difference_type difference_type;
Chris@16:         typedef const value_type & const_reference;
Chris@16: 
Chris@16:         // do NOT define reference type, because class is read only
Chris@16:         // typedef value_type & reference;
Chris@16: 
Chris@16:         typedef IA rowptr_array_type;
Chris@16:         typedef JA index_array_type;
Chris@16:         typedef TA value_array_type;
Chris@16:         typedef const matrix_reference<const self_type> const_closure_type;
Chris@16:         typedef matrix_reference<self_type> closure_type;
Chris@16: 
Chris@16:         // FIXME: define a corresponding temporary type
Chris@16:         // typedef compressed_vector<T, IB, IA, TA> vector_temporary_type;
Chris@16: 
Chris@16:         // FIXME: define a corresponding temporary type
Chris@16:         // typedef self_type matrix_temporary_type;
Chris@16: 
Chris@16:         typedef sparse_tag storage_category;
Chris@16:         typedef typename L::orientation_category orientation_category;
Chris@16: 
Chris@16:         //
Chris@16:         // private types for internal use
Chris@16:         //
Chris@16: 
Chris@16:     private:
Chris@16:         typedef typename vector_view_traits<index_array_type>::const_iterator const_subiterator_type;
Chris@16: 
Chris@16:         //
Chris@16:         // Construction and destruction
Chris@16:         //
Chris@16:     private:
Chris@16:         /// private default constructor because data must be filled by caller
Chris@16:         BOOST_UBLAS_INLINE
Chris@16:         compressed_matrix_view () { }
Chris@16: 
Chris@16:     public:
Chris@16:         BOOST_UBLAS_INLINE
Chris@16:         compressed_matrix_view (index_type n_rows, index_type n_cols, array_size_type nnz
Chris@16:                                 , const rowptr_array_type & iptr
Chris@16:                                 , const index_array_type & jptr
Chris@16:                                 , const value_array_type & values):
Chris@16:             matrix_expression<self_type> (),
Chris@16:             size1_ (n_rows), size2_ (n_cols), 
Chris@16:             nnz_ (nnz),
Chris@16:             index1_data_ (iptr), 
Chris@16:             index2_data_ (jptr), 
Chris@16:             value_data_ (values) {
Chris@16:             storage_invariants ();
Chris@16:         }
Chris@16: 
Chris@16:         BOOST_UBLAS_INLINE
Chris@16:         compressed_matrix_view(const compressed_matrix_view& o) :
Chris@101:             size1_(o.size1_), size2_(o.size2_),
Chris@101:             nnz_(o.nnz_),
Chris@101:             index1_data_(o.index1_data_),
Chris@101:             index2_data_(o.index2_data_),
Chris@101:             value_data_(o.value_data_)
Chris@16:         {}
Chris@16: 
Chris@16:         //
Chris@16:         // implement immutable iterator types
Chris@16:         //
Chris@16: 
Chris@16:         class const_iterator1 {};
Chris@16:         class const_iterator2 {};
Chris@16: 
Chris@16:         typedef reverse_iterator_base1<const_iterator1> const_reverse_iterator1;
Chris@16:         typedef reverse_iterator_base2<const_iterator2> const_reverse_iterator2;
Chris@16: 
Chris@16:         //
Chris@16:         // implement all read only methods for the matrix expression concept
Chris@16:         // 
Chris@16: 
Chris@16:         //! return the number of rows 
Chris@16:         index_type size1() const {
Chris@16:             return size1_;
Chris@16:         }
Chris@16: 
Chris@16:         //! return the number of columns
Chris@16:         index_type size2() const {
Chris@16:             return size2_;
Chris@16:         }
Chris@16: 
Chris@16:         //! return value at position (i,j)
Chris@16:         value_type operator()(index_type i, index_type j) const {
Chris@16:             const_pointer p = find_element(i,j);
Chris@16:             if (!p) {
Chris@16:                 return zero_;
Chris@16:             } else {
Chris@16:                 return *p;
Chris@16:             }
Chris@16:         }
Chris@16:         
Chris@16: 
Chris@16:     private:
Chris@16:         //
Chris@16:         // private helper functions
Chris@16:         //
Chris@16: 
Chris@16:         const_pointer find_element (index_type i, index_type j) const {
Chris@16:             index_type element1 (layout_type::index_M (i, j));
Chris@16:             index_type element2 (layout_type::index_m (i, j));
Chris@16: 
Chris@16:             const array_size_type itv      = zero_based( index1_data_[element1] );
Chris@16:             const array_size_type itv_next = zero_based( index1_data_[element1+1] );
Chris@16: 
Chris@16:             const_subiterator_type it_start = boost::next(vector_view_traits<index_array_type>::begin(index2_data_),itv);
Chris@16:             const_subiterator_type it_end = boost::next(vector_view_traits<index_array_type>::begin(index2_data_),itv_next);
Chris@16:             const_subiterator_type it = find_index_in_row(it_start, it_end, element2) ;
Chris@16:             
Chris@16:             if (it == it_end || *it != k_based (element2))
Chris@16:                 return 0;
Chris@16:             return &value_data_ [it - vector_view_traits<index_array_type>::begin(index2_data_)];
Chris@16:         }
Chris@16: 
Chris@16:         const_subiterator_type find_index_in_row(const_subiterator_type it_start
Chris@16:                                                  , const_subiterator_type it_end
Chris@16:                                                  , index_type index) const {
Chris@16:             return std::lower_bound( it_start
Chris@16:                                      , it_end
Chris@16:                                      , k_based (index) );
Chris@16:         }
Chris@16: 
Chris@16: 
Chris@16:     private:
Chris@16:         void storage_invariants () const {
Chris@16:             BOOST_UBLAS_CHECK (index1_data_ [layout_type::size_M (size1_, size2_)] == k_based (nnz_), external_logic ());
Chris@16:         }
Chris@16:         
Chris@16:         index_type size1_;
Chris@16:         index_type size2_;
Chris@16: 
Chris@16:         array_size_type nnz_;
Chris@16: 
Chris@16:         const rowptr_array_type & index1_data_;
Chris@16:         const index_array_type & index2_data_;
Chris@16:         const value_array_type & value_data_;
Chris@16: 
Chris@16:         static const value_type zero_;
Chris@16: 
Chris@16:         BOOST_UBLAS_INLINE
Chris@16:         static index_type zero_based (index_type k_based_index) {
Chris@16:             return k_based_index - IB;
Chris@16:         }
Chris@16:         BOOST_UBLAS_INLINE
Chris@16:         static index_type k_based (index_type zero_based_index) {
Chris@16:             return zero_based_index + IB;
Chris@16:         }
Chris@16: 
Chris@16:         friend class iterator1;
Chris@16:         friend class iterator2;
Chris@16:         friend class const_iterator1;
Chris@16:         friend class const_iterator2;
Chris@16:     };
Chris@16: 
Chris@16:     template<class L, std::size_t IB, class IA, class JA, class TA  >
Chris@16:     const typename compressed_matrix_view<L,IB,IA,JA,TA>::value_type 
Chris@16:     compressed_matrix_view<L,IB,IA,JA,TA>::zero_ = value_type/*zero*/();
Chris@16: 
Chris@16: 
Chris@16:     template<class L, std::size_t IB, class IA, class JA, class TA  >
Chris@16:     compressed_matrix_view<L,IB,IA,JA,TA>
Chris@16:     make_compressed_matrix_view(typename vector_view_traits<JA>::value_type n_rows
Chris@16:                                 , typename vector_view_traits<JA>::value_type n_cols
Chris@16:                                 , typename vector_view_traits<JA>::size_type nnz
Chris@16:                                 , const IA & ia
Chris@16:                                 , const JA & ja
Chris@16:                                 , const TA & ta) {
Chris@16: 
Chris@16:         return compressed_matrix_view<L,IB,IA,JA,TA>(n_rows, n_cols, nnz, ia, ja, ta);
Chris@16: 
Chris@16:     }
Chris@16: 
Chris@16: }}}
Chris@16: 
Chris@16: #endif