c++boost.gif 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

    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