vector_sparse.hpp

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//
//  Copyright (c) 2000-2002
//  Joerg Walter, Mathias Koch
//
//  Permission to use, copy, modify, distribute and sell this software
//  and its documentation for any purpose is hereby granted without fee,
//  provided that the above copyright notice appear in all copies and
//  that both that copyright notice and this permission notice appear
//  in supporting documentation.  The authors make no representations
//  about the suitability of this software for any purpose.
//  It is provided "as is" without express or implied warranty.
//
//  The authors gratefully acknowledge the support of
//  GeNeSys mbH & Co. KG in producing this work.
//

#ifndef BOOST_UBLAS_VECTOR_SPARSE_H
#define BOOST_UBLAS_VECTOR_SPARSE_H

#include <boost/numeric/ublas/config.hpp>
#include <boost/numeric/ublas/storage_sparse.hpp>
#include <boost/numeric/ublas/vector.hpp>

// Iterators based on ideas of Jeremy Siek

namespace boost { namespace numeric { namespace ublas {

#ifdef BOOST_UBLAS_STRICT_VECTOR_SPARSE

    template<class V>
    class sparse_vector_element:
       public container_reference<V> {
    public:
        typedef V vector_type;
        typedef typename V::size_type size_type;
        typedef typename V::value_type value_type;
        typedef const value_type &const_reference;
        typedef value_type *pointer;

        // Construction and destruction
        sparse_vector_element (vector_type &v, size_type i):
            container_reference<vector_type> (v), i_ (i), d_ (), dirty_ (false) {
            pointer it = (*this) ().find_element (i_);
            if (it)
                d_ = *it;
        }
        BOOST_UBLAS_INLINE
        sparse_vector_element (const sparse_vector_element &p):
            container_reference<vector_type> (p), i_ (p.i_), d_ (p.d_), dirty_ (p.dirty_) {}
        BOOST_UBLAS_INLINE
        ~sparse_vector_element () {
            if (dirty_) {
                pointer it = (*this) ().find_element (i_);
                if (! it)
                    (*this) ().insert (i_, d_);
                else
                    *it = d_;
            }
        }

        // Assignment
        BOOST_UBLAS_INLINE
        sparse_vector_element &operator = (const sparse_vector_element &p) {
            // Overide the implict copy assignment
            d_ = p.d_;
            dirty_ = true;
            return *this;
        }
        template<class D>
        BOOST_UBLAS_INLINE
        sparse_vector_element &operator = (const D &d) {
            d_ = d;
            dirty_ = true;
            return *this;
        }
        template<class D>
        BOOST_UBLAS_INLINE
        sparse_vector_element &operator += (const D &d) {
            d_ += d;
            dirty_ = true;
            return *this;
        }
        template<class D>
        BOOST_UBLAS_INLINE
        sparse_vector_element &operator -= (const D &d) {
            d_ -= d;
            dirty_ = true;
            return *this;
        }
        template<class D>
        BOOST_UBLAS_INLINE
        sparse_vector_element &operator *= (const D &d) {
            d_ *= d;
            dirty_ = true;
            return *this;
        }
        template<class D>
        BOOST_UBLAS_INLINE
        sparse_vector_element &operator /= (const D &d) {
            d_ /= d;
            dirty_ = true;
            return *this;
        }

        // Comparison
        template<class D>
        BOOST_UBLAS_INLINE
        bool operator == (const D &d) const {
            return d_ == d;
        }
        template<class D>
        BOOST_UBLAS_INLINE
        bool operator != (const D &d) const {
            return d_ != d;
        }

        // Conversion
        BOOST_UBLAS_INLINE
        operator const_reference () const {
            return d_;
        }
        // Swapping
        BOOST_UBLAS_INLINE
        void swap (sparse_vector_element p) {
            if (this != &p) {
                dirty_ = true;
                p.dirty_ = true;
                std::swap (d_, p.d_);
            }
        }
#ifndef BOOST_UBLAS_NO_MEMBER_FRIENDS
        BOOST_UBLAS_INLINE
        friend void swap (sparse_vector_element p1, sparse_vector_element p2) {
            p1.swap (p2);
        }
#endif

    private:
        size_type i_;
        value_type d_;
        bool dirty_;
    };

    template<class V>
    struct type_traits<sparse_vector_element<V> > {
        typedef typename V::value_type element_type;
        typedef type_traits<sparse_vector_element<V> > self_type;
        typedef typename type_traits<element_type>::value_type value_type;
        typedef typename type_traits<element_type>::const_reference const_reference;
        typedef sparse_vector_element<V> reference;
        typedef typename type_traits<element_type>::real_type real_type;
        typedef typename type_traits<element_type>::precision_type precision_type;

        BOOST_STATIC_CONSTANT (unsigned, plus_complexity = type_traits<element_type>::plus_complexity);
        BOOST_STATIC_CONSTANT (unsigned, multiplies_complexity = type_traits<element_type>::multiplies_complexity);

        static
        BOOST_UBLAS_INLINE
        real_type real (const_reference t) {
            return type_traits<element_type>::real (t);
        }
        static
        BOOST_UBLAS_INLINE
        real_type imag (const_reference t) {
            return type_traits<element_type>::imag (t);
        }
        static
        BOOST_UBLAS_INLINE
        value_type conj (const_reference t) {
            return type_traits<element_type>::conj (t);
        }

        static
        BOOST_UBLAS_INLINE
        real_type abs (const_reference t) {
            return type_traits<element_type>::abs (t);
        }
        static
        BOOST_UBLAS_INLINE
        value_type sqrt (const_reference t) {
            return type_traits<element_type>::sqrt (t);
        }

        static
        BOOST_UBLAS_INLINE
        real_type norm_1 (const_reference t) {
            return type_traits<element_type>::norm_1 (t);
        }
        static
        BOOST_UBLAS_INLINE
        real_type norm_2 (const_reference t) {
            return type_traits<element_type>::norm_2 (t);
        }
        static
        BOOST_UBLAS_INLINE
        real_type norm_inf (const_reference t) {
            return type_traits<element_type>::norm_inf (t);
        }

        static
        BOOST_UBLAS_INLINE
        bool equals (const_reference t1, const_reference t2) {
            return type_traits<element_type>::equals (t1, t2);
        }
    };

    template<class V1, class T2>
    struct promote_traits<sparse_vector_element<V1>, T2> {
        typedef typename promote_traits<typename sparse_vector_element<V1>::value_type, T2>::promote_type promote_type;
    };
    template<class T1, class V2>
    struct promote_traits<T1, sparse_vector_element<V2> > {
        typedef typename promote_traits<T1, typename sparse_vector_element<V2>::value_type>::promote_type promote_type;
    };
    template<class V1, class V2>
    struct promote_traits<sparse_vector_element<V1>, sparse_vector_element<V2> > {
        typedef typename promote_traits<typename sparse_vector_element<V1>::value_type,
                                        typename sparse_vector_element<V2>::value_type>::promote_type promote_type;
    };

#endif


    // Array based sparse vector class
    template<class T, class A>
    class sparse_vector:
        public vector_expression<sparse_vector<T, A> > {
    public:
#ifndef BOOST_UBLAS_NO_PROXY_SHORTCUTS
        BOOST_UBLAS_USING vector_expression<sparse_vector<T, A> >::operator ();
#endif
        typedef typename A::size_type size_type;
        typedef typename A::difference_type difference_type;
        typedef T value_type;
        typedef A array_type;
        typedef const value_type &const_reference;
#ifndef BOOST_UBLAS_STRICT_VECTOR_SPARSE
        typedef BOOST_UBLAS_TYPENAME detail::map_traits<A,T>::reference reference;
#else
        typedef sparse_vector_element<sparse_vector<T, A> > reference;
#endif
    private:
        typedef T &true_reference;
        typedef T *pointer;
        typedef sparse_vector<T, A> self_type;
    public:
#ifndef BOOST_UBLAS_CT_REFERENCE_BASE_TYPEDEFS
        typedef const vector_const_reference<const self_type> const_closure_type;
#else
        typedef const vector_reference<const self_type> const_closure_type;
#endif
        typedef vector_reference<self_type> closure_type;
        typedef self_type vector_temporary_type;
        typedef sparse_tag storage_category;

        // Construction and destruction
        BOOST_UBLAS_INLINE
        sparse_vector ():
            vector_expression<self_type> (),
            size_ (0), data_ () {}
        BOOST_UBLAS_INLINE
        sparse_vector (size_type size, size_type non_zeros = 0):
            vector_expression<self_type> (),
            size_ (size), data_ () {
            detail::map_reserve (data(), non_zeros);
        }
        BOOST_UBLAS_INLINE
        sparse_vector (const sparse_vector &v):
            vector_expression<self_type> (),
            size_ (v.size_), data_ (v.data_) {}
        template<class AE>
        BOOST_UBLAS_INLINE
        sparse_vector (const vector_expression<AE> &ae, size_type non_zeros = 0):
            vector_expression<self_type> (),
            size_ (ae ().size ()), data_ () {
            detail::map_reserve (data(), non_zeros);
            vector_assign (scalar_assign<true_reference, BOOST_UBLAS_TYPENAME AE::value_type> (), *this, ae);
        }

        // Accessors
        BOOST_UBLAS_INLINE
        size_type size () const {
            return size_;
        }
        BOOST_UBLAS_INLINE
        size_type non_zeros () const {
            return detail::map_capacity (data ());
        }
        BOOST_UBLAS_INLINE
        const array_type &data () const {
            return data_;
        }
        BOOST_UBLAS_INLINE
        array_type &data () {
            return data_;
        }

        // Resizing
        BOOST_UBLAS_INLINE
        void resize (size_type size, bool preserve = true) {
            size_ = size;
            if (preserve) {
                data ().erase (data ().lower_bound(size_), data ().end());
            }
            else {
                data ().clear ();
            }
        }

        // Reserving
        BOOST_UBLAS_INLINE
        void reserve (size_type non_zeros = 0, bool preserve = true) {
            detail::map_reserve (data (), non_zeros);
        }

        // Proxy support
#ifdef BOOST_UBLAS_STRICT_VECTOR_SPARSE
        pointer find_element (size_type i) {
            iterator_type it (data ().find (i));
            if (it == data ().end () || (*it).first != i)
                return 0;
            return &(*it).second;
        }
#endif

        // Element access
        BOOST_UBLAS_INLINE
        const_reference operator () (size_type i) const {
            BOOST_UBLAS_CHECK (i < size_, bad_index ());
            const_iterator_type it (data ().find (i));
            if (it == data ().end () || (*it).first != i)
                return zero_;
            return (*it).second;
        }
        BOOST_UBLAS_INLINE
        reference operator () (size_type i) {
            BOOST_UBLAS_CHECK (i < size_, bad_index ());
#ifndef BOOST_UBLAS_STRICT_VECTOR_SPARSE
            return data () [i];
#else
            return reference (*this, i);
#endif
        }

        BOOST_UBLAS_INLINE
        const_reference operator [] (size_type i) const {
            return (*this) (i);
        }
        BOOST_UBLAS_INLINE
        reference operator [] (size_type i) {
            return (*this) (i);
        }

        // Assignment
        BOOST_UBLAS_INLINE
        sparse_vector &operator = (const sparse_vector &v) {
            if (this != &v) {
                size_ = v.size_;