Vector Proxies

Vector Range

Description

The templated class vector_range<V> allows addressing a range of a vector.

Example

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

#include <boost/numeric/ublas/io.hpp>



int main () {

    using namespace boost::numeric::ublas;

    vector<double> v (3);

    vector_range<vector<double> > vr (v, range (0, 3));

    for (unsigned i = 0; i < vr.size (); ++ i)

        vr (i) = i;

    std::cout << vr << std::endl;

}

Definition

Defined in the header vector_proxy.hpp.

Template parameters

Parameter	Description	Default
`V`	The type of vector referenced.

Model of

Vector Expression .

Type requirements

None, except for those imposed by the requirements of Vector Expression .

Public base classes

vector_expression<vector_range<V> >

Members

Member	Description
`vector_range (vector_type &data, const range &r)`	Constructs a sub vector.
`size_type start () const`	Returns the start of the sub vector.
`size_type size () const`	Returns the size of the sub vector.
`const_reference operator () (size_type i) const`	Returns the value of the `i`-th element.
`reference operator () (size_type i)`	Returns a reference of the `i`-th element.
`const_reference operator [] (size_type i) const`	Returns the value of the `i`-th element.
`reference operator [] (size_type i)`	Returns a reference of the `i`-th element.
`vector_range &operator = (const vector_range &vr)`	The assignment operator.
`vector_range &assign_temporary (vector_range &vr)`	Assigns a temporary. May change the vector range `vr` .
`template<class AE> vector_range &operator = (const vector_expression<AE> &ae)`	The extended assignment operator.
`template<class AE> vector_range &assign (const vector_expression<AE> &ae)`	Assigns a vector expression to the sub vector. Left and right hand side of the assignment should be independent.
`template<class AE> vector_range &operator += (const vector_expression<AE> &ae)`	A computed assignment operator. Adds the vector expression to the sub vector.
`template<class AE> vector_range &plus_assign (const vector_expression<AE> &ae)`	Adds a vector expression to the sub vector. Left and right hand side of the assignment should be independent.
`template<class AE> vector_range &operator -= (const vector_expression<AE> &ae)`	A computed assignment operator. Subtracts the vector expression from the sub vector.
`template<class AE> vector_range &minus_assign (const vector_expression<AE> &ae)`	Subtracts a vector expression from the sub vector. Left and right hand side of the assignment should be independent.
`template<class AT> vector_range &operator *= (const AT &at)`	A computed assignment operator. Multiplies the sub vector with a scalar.
`template<class AT> vector_range &operator /= (const AT &at)`	A computed assignment operator. Divides the sub vector through a scalar.
`void swap (vector_range &vr)`	Swaps the contents of the sub vectors.
`const_iterator begin () const`	Returns a `const_iterator` pointing to the beginning of the `vector_range`.
`const_iterator end () const`	Returns a `const_iterator` pointing to the end of the `vector_range`.
`iterator begin ()`	Returns a `iterator` pointing to the beginning of the `vector_range`.
`iterator end ()`	Returns a `iterator` pointing to the end of the `vector_range`.
`const_reverse_iterator rbegin () const`	Returns a `const_reverse_iterator` pointing to the beginning of the reversed `vector_range`.
`const_reverse_iterator rend () const`	Returns a `const_reverse_iterator` pointing to the end of the reversed `vector_range`.
`reverse_iterator rbegin ()`	Returns a `reverse_iterator` pointing to the beginning of the reversed `vector_range`.
`reverse_iterator rend ()`	Returns a `reverse_iterator` pointing to the end of the reversed `vector_range`.

Interface

// Vector based range class

    template<class V>

    class vector_range:

        public vector_expression<vector_range<V> > {

    public:

        typedef const V const_vector_type;

        typedef V vector_type;

        typedef typename V::size_type size_type;

        typedef typename V::difference_type difference_type;

        typedef typename V::value_type value_type;

        typedef typename V::const_reference const_reference;

        typedef typename V::reference reference;

        typedef typename V::const_pointer const_pointer;

        typedef typename V::pointer pointer;

        typedef const vector_const_reference<const vector_range<vector_type> > const_closure_type;

        typedef vector_reference<vector_range<vector_type> > closure_type;

        typedef typename V::const_iterator const_iterator_type;

        typedef typename V::iterator iterator_type;

        typedef typename storage_restrict_traits<typename V::storage_category,

                                                 dense_proxy_tag>::storage_category storage_category;



        // Construction and destruction

        vector_range ();

        vector_range (vector_type &data, const range &r);



        // Accessors

        size_type start () const;

        size_type size () const;

        const_vector_type &data () const;

        vector_type &data ();





        // Element access

        const_reference operator () (size_type i) const;

        reference operator () (size_type i);



        const_reference operator [] (size_type i) const;

        reference operator [] (size_type i);



        vector_range<vector_type> project (const range &r) const;



        // Assignment

        vector_range &operator = (const vector_range &vr);

        vector_range &assign_temporary (vector_range &vr);

        template<class AE>

        vector_range &operator = (const vector_expression<AE> &ae);

        template<class AE>

        vector_range &assign (const vector_expression<AE> &ae);

        template<class AE>

        vector_range &operator += (const vector_expression<AE> &ae);

        template<class AE>

        vector_range &plus_assign (const vector_expression<AE> &ae);

        template<class AE>

        vector_range &operator -= (const vector_expression<AE> &ae);

        template<class AE>

        vector_range &minus_assign (const vector_expression<AE> &ae);

        template<class AT>

        vector_range &operator *= (const AT &at);

        template<class AT>

        vector_range &operator /= (const AT &at);



        // Swapping

        void swap (vector_range &vr);

        friend void swap (vector_range &vr1, vector_range &vr2);



        class const_iterator;

        class iterator;



        // Element lookup

        const_iterator find_first (size_type i) const;

        iterator find_first (size_type i);

        const_iterator find_last (size_type i) const;

        iterator find_last (size_type i);



        // Iterators simply are pointers.



        class const_iterator:

            public container_const_reference<vector_range>,

            public random_access_iterator_base<const_iterator, value_type> {

        public:

            typedef typename const_iterator_type::iterator_category iterator_category;

            typedef typename const_iterator_type::difference_type difference_type;

            typedef typename const_iterator_type::value_type value_type;

            typedef typename const_iterator_type::reference reference;

            typedef typename const_iterator_type::pointer pointer;



            // Construction and destruction

            const_iterator ();

            const_iterator (const vector_range &vr, const const_iterator_type &it);

            const_iterator (const iterator &it);



            // Arithmetic

            const_iterator &operator ++ ();

            const_iterator &operator -- ();

            const_iterator &operator += (difference_type n);

            const_iterator &operator -= (difference_type n);

            difference_type operator - (const const_iterator &it) const;



            // Dereference

            reference operator * () const;



            // Index

            size_type index () const;



            // Assignment

            const_iterator &operator = (const const_iterator &it);



            // Comparison

            bool operator == (const const_iterator &it) const;

            bool operator <(const const_iterator &it) const;

        };



        const_iterator begin () const;

        const_iterator end () const;



        class iterator:

            public container_reference<vector_range>,

            public random_access_iterator_base<iterator, value_type> {

        public:

            typedef typename iterator_type::iterator_category iterator_category;

            typedef typename iterator_type::difference_type difference_type;

            typedef typename iterator_type::value_type value_type;

            typedef typename iterator_type::reference reference;

            typedef typename iterator_type::pointer pointer;



            // Construction and destruction

            iterator ();

            iterator (vector_range &vr, const iterator_type &it);



            // Arithmetic

            iterator &operator ++ ();

            iterator &operator -- ();

            iterator &operator += (difference_type n);

            iterator &operator -= (difference_type n);

            difference_type operator - (const iterator &it) const;



            // Dereference

            reference operator * () const;



            // Index

            size_type index () const;



            // Assignment

            iterator &operator = (const iterator &it);



            // Comparison

            bool operator == (const iterator &it) const;

            bool operator <(const iterator &it) const;

        };



        iterator begin ();

        iterator end ();



        // Reverse iterator



        typedef reverse_iterator_base<const_iterator> const_reverse_iterator;



        const_reverse_iterator rbegin () const;

        const_reverse_iterator rend () const;



        typedef reverse_iterator_base<iterator> reverse_iterator;



        reverse_iterator rbegin ();

        reverse_iterator rend ();

    };

Projections

Prototypes

template<class V>

    vector_range<V> project (V &data, const range &r);

    template<class V>

    const vector_range<const V> project (const V &data, const range &r);

    template<class V>

    vector_range<V> project (const vector_range<V> &data, const range &r);

Description

The free project functions support the construction of vector ranges.

Definition

Defined in the header vector_proxy.hpp.

Type requirements

V is a model of Vector Expression .

Preconditions

r.start () + r.size () <= data.size ()

Complexity

Linear depending from the size of the range.

Examples

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

#include <boost/numeric/ublas/io.hpp>



int main () {

    using namespace boost::numeric::ublas;

    vector<double> v (3);

    for (int i = 0; i < 3; ++ i)

        project (v, range (0, 3)) (i) = i;

    std::cout << project (v, range (0, 3)) << std::endl;

}

Vector Slice

Description

The templated class vector_slice<V> allows addressing a slice of a vector.

Example

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

#include <boost/numeric/ublas/io.hpp>



int main () {

    using namespace boost::numeric::ublas;

    vector<double> v (3);

    vector_slice<vector<double> > vs (v, slice (0, 1, 3));

    for (unsigned i = 0; i < vs.size (); ++ i)

        vs (i) = i;

    std::cout << vs << std::endl;

}

Definition

Defined in the header vector_proxy.hpp.

Template parameters

Parameter	Description	Default
`V`	The type of vector referenced.

Model of

Vector Expression .

Type requirements

None, except for those imposed by the requirements of Vector Expression .

Public base classes

vector_expression<vector_slice<V> >

Members

Member	Description
`vector_slice (vector_type &data, const slice &s)`	Constructs a sub vector.
`size_type size () const`	Returns the size of the sub vector.
`const_reference operator () (size_type i) const`	Returns the value of the `i`-th element.
`reference operator () (size_type i)`	Returns a reference of the `i`-th element.
`const_reference operator [] (size_type i) const`	Returns the value of the `i`-th element.
`reference operator [] (size_type i)`	Returns a reference of the `i`-th element.
`vector_slice &operator = (const vector_slice &vs)`	The assignment operator.
`vector_slice &assign_temporary (vector_slice &vs)`	Assigns a temporary. May change the vector slice `vs` .
`template<class AE> vector_slice &operator = (const vector_expression<AE> &ae)`	The extended assignment operator.
`template<class AE> vector_slice &assign (const vector_expression<AE> &ae)`	Assigns a vector expression to the sub vector. Left and right hand side of the assignment should be independent.
`template<class AE> vector_slice &operator += (const vector_expression<AE> &ae)`	A computed assignment operator. Adds the vector expression to the sub vector.
`template<class AE> vector_slice &plus_assign (const vector_expression<AE> &ae)`	Adds a vector expression to the sub vector. Left and right hand side of the assignment should be independent.
`template<class AE> vector_slice &operator -= (const vector_expression<AE> &ae)`	A computed assignment operator. Subtracts the vector expression from the sub vector.
`template<class AE> vector_slice &minus_assign (const vector_expression<AE> &ae)`	Subtracts a vector expression from the sub vector. Left and right hand side of the assignment should be independent.
`template<class AT> vector_slice &operator *= (const AT &at)`	A computed assignment operator. Multiplies the sub vector with a scalar.
`template<class AT> vector_slice &operator /= (const AT &at)`	A computed assignment operator. Divides the sub vector through a scalar.
`void swap (vector_slice &vs)`	Swaps the contents of the sub vectors.
`const_iterator begin () const`	Returns a `const_iterator` pointing to the beginning of the `vector_slice`.
`const_iterator end () const`	Returns a `const_iterator` pointing to the end of the `vector_slice`.
`iterator begin ()`	Returns a `iterator` pointing to the beginning of the `vector_slice`.
`iterator end ()`	Returns a `iterator` pointing to the end of the `vector_slice`.
`const_reverse_iterator rbegin () const`	Returns a `const_reverse_iterator` pointing to the beginning of the reversed `vector_slice`.
`const_reverse_iterator rend () const`	Returns a `const_reverse_iterator` pointing to the end of the reversed `vector_slice`.
`reverse_iterator rbegin ()`	Returns a `reverse_iterator` pointing to the beginning of the reversed `vector_slice`.
`reverse_iterator rend ()`	Returns a `reverse_iterator` pointing to the end of the reversed `vector_slice`.

Interface

// Vector based slice class

    template<class V>

    class vector_slice:

        public vector_expression<vector_slice<V> > {

    public:

        typedef const V const_vector_type;

        typedef V vector_type;

        typedef typename V::size_type size_type;

        typedef typename V::difference_type difference_type;

        typedef typename V::value_type value_type;

        typedef typename V::const_reference const_reference;

        typedef typename V::reference reference;

        typedef typename V::const_pointer const_pointer;

        typedef typename V::pointer pointer;

        typedef const vector_const_reference<const vector_slice<vector_type> > const_closure_type;

        typedef vector_reference<vector_slice<vector_type> > closure_type;

        typedef slice::const_iterator const_iterator_type;

        typedef slice::const_iterator iterator_type;

        typedef typename storage_restrict_traits<typename V::storage_category,

                                                 dense_proxy_tag>::storage_category storage_category;



        // Construction and destruction

        vector_slice ();

        vector_slice (vector_type &data, const slice &s);



        // Accessors

        size_type start () const;

        size_type stride () const;

        size_type size () const;

        const_vector_type &data () const;

        vector_type &data ();





        // Element access

        const_reference operator () (size_type i) const;

        reference operator () (size_type i);



        const_reference operator [] (size_type i) const;

        reference operator [] (size_type i);



        vector_slice<vector_type> project (const range &r) const;

        vector_slice<vector_type> project (const slice &s) const;



        // Assignment

        vector_slice &operator = (const vector_slice &vs);

        vector_slice &assign_temporary (vector_slice &vs);

        template<class AE>

        vector_slice &operator = (const vector_expression<AE> &ae);

        template<class AE>

        vector_slice &assign (const vector_expression<AE> &ae);

        template<class AE>

        vector_slice &operator += (const vector_expression<AE> &ae);

        template<class AE>

        vector_slice &plus_assign (const vector_expression<AE> &ae);

        template<class AE>

        vector_slice &operator -= (const vector_expression<AE> &ae);

        template<class AE>

        vector_slice &minus_assign (const vector_expression<AE> &ae);

        template<class AT>

        vector_slice &operator *= (const AT &at);

        template<class AT>

        vector_slice &operator /= (const AT &at);



        // Swapping

        void swap (vector_slice &vs);

        friend void swap (vector_slice &vs1, vector_slice &vs2);



        class const_iterator;

        class iterator;



        // Element lookup

        const_iterator find_first (size_type i) const;

        iterator find_first (size_type i);

        const_iterator find_last (size_type i) const;

        iterator find_last (size_type i);



        // Iterators simply are indices.



        class const_iterator:

            public container_const_reference<vector_slice>,

            public random_access_iterator_base<const_iterator, value_type> {

        public:

            typedef typename V::const_iterator::iterator_category iterator_category;

            typedef typename V::const_iterator::difference_type difference_type;

            typedef typename V::const_iterator::value_type value_type;

            typedef typename V::const_iterator::reference reference;

            typedef typename V::const_iterator::pointer pointer;



            // Construction and destruction

            const_iterator ();

            const_iterator (const vector_slice &vs, const const_iterator_type &it);

            const_iterator (const iterator &it);



            // Arithmetic

            const_iterator &operator ++ ();

            const_iterator &operator -- ();

            const_iterator &operator += (difference_type n);

            const_iterator &operator -= (difference_type n);

            difference_type operator - (const const_iterator &it) const;



            // Dereference

            reference operator * () const;



            // Index

            size_type index () const;



            // Assignment

            const_iterator &operator = (const const_iterator &it);



            // Comparison

            bool operator == (const const_iterator &it) const;

            bool operator <(const const_iterator &it) const;

        };



        const_iterator begin () const;

        const_iterator end () const;



        class iterator:

            public container_reference<vector_slice>,

            public random_access_iterator_base<iterator, value_type> {

        public:

            typedef typename V::iterator::iterator_category iterator_category;

            typedef typename V::iterator::difference_type difference_type;

            typedef typename V::iterator::value_type value_type;

            typedef typename V::iterator::reference reference;

            typedef typename V::iterator::pointer pointer;



            // Construction and destruction

            iterator ();

            iterator (vector_slice &vs, const iterator_type &it);



            // Arithmetic

            iterator &operator ++ ();

            iterator &operator -- ();

            iterator &operator += (difference_type n);

            iterator &operator -= (difference_type n);

            difference_type operator - (const iterator &it) const;



            // Dereference

            reference operator * () const;



            // Index

            size_type index () const;



            // Assignment

            iterator &operator = (const iterator &it);



            // Comparison

            bool operator == (const iterator &it) const;

            bool operator <(const iterator &it) const;

        };



        iterator begin ();

        iterator end ();



        // Reverse iterator



        typedef reverse_iterator_base<const_iterator> const_reverse_iterator;



        const_reverse_iterator rbegin () const;

        const_reverse_iterator rend () const;



        typedef reverse_iterator_base<iterator> reverse_iterator;



        reverse_iterator rbegin ();

        reverse_iterator rend ();

    };

Projections

Prototypes

template<class V>

    vector_slice<V> project (const vector_slice<V> &data, const range &r);

    template<class V>

    vector_slice<V> project (V &data, const slice &s);

    template<class V>

    const vector_slice<const V> project (const V &data, const slice &s);

    template<class V>

    vector_slice<V> project (const vector_slice<V> &data, const slice &s);

Description

The free project functions support the construction of vector slices.

Definition

Defined in the header vector_proxy.hpp.

Type requirements

V is a model of Vector Expression .

Preconditions

s.start () + s.stride () * s.size () <= data.size ()

Complexity

Linear depending from the size of the slice.

Examples

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

#include <boost/numeric/ublas/io.hpp>



int main () {

    using namespace boost::numeric::ublas;

    vector<double> v (3);

    for (int i = 0; i < 3; ++ i)

        project (v, slice (0, 1, 3)) (i) = i;

    std::cout << project (v, slice (0, 1, 3)) << std::endl;

}

Copyright (©) 2000-2002 Joerg Walter, Mathias Koch
Permission to copy, use, modify, sell and distribute this document is granted provided this copyright notice appears in all copies. This document is provided ``as is'' without express or implied warranty, and with no claim as to its suitability for any purpose.

Last revised: 1/15/2003