Vector Proxies

Vector Range

Description

The templated class vector_range<V> allows addressing a sub-range of a vector's element.

Example

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

If the specified range falls outside that of the index range of the vector, then the vector_range is not a well formed Vector Expression. That is, access to an element which is outside of index range of the vector is undefined.

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`.

Simple Projections

Description

The free subrange functions support the construction of vector ranges.

Prototypes


    template<class V>
    vector_range<V> subrange (V &data,
       V::size_type start, V::size_type stop);
    template<class V>
    const vector_range<const V> subrange (const V &data,
       V::size_type start, V::size_type stop);

Generic Projections

Description

The free project functions support the construction of vector ranges. Existing matrix_range's can be composed with a further range. The resulting range is computed using this existing range's compose function.

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

Definition

Defined in the header vector_proxy.hpp.

Type requirements

V is a model of Vector Expression .

Complexity

Linear depending from the size of the range.

Examples

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

If the specified slice falls outside that of the index range of the vector, then the vector_slice is not a well formed Vector Expression. That is, access to an element which is outside of index range of the vector is undefined.

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`.

Simple Projections

Description

The free subslice functions support the construction of vector slices.

Prototypes


    template<class V>
    vector_slice<V> subslice (V &data,
       V::size_type start, V::difference_type stride, V::size_type size);
    template<class V>
    const vector_slice<const V> subslice (const V &data,
       V::size_type start, V::difference_type stride, V::size_type size);

Generic Projections

Description

The free project functions support the construction of vector slices. Existing vector_slice's can be composed with a further range or slices. The resulting slice is computed using this existing slices's compose function.

Prototypes


    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 (vector_slice<V> &data, const range &r);
    template<class V>
    const vector_slice<V> project (const vector_slice<V> &data, const range &r);
    template<class V>
    vector_slice<V> project (vector_slice<V> &data, const slice &s);
    template<class V>
    const vector_slice<V> project (const vector_slice<V> &data, const slice &s);

Definition

Defined in the header vector_proxy.hpp.

Type requirements

V is a model of Vector Expression .

Complexity

Linear depending from the size of the slice.

Examples

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