Boost C++ Libraries

...one of the most highly regarded and expertly designed C++ library projects in the world. Herb Sutter and Andrei Alexandrescu, C++ Coding Standards

Triangular Matrix

Triangular Matrix

Description

The templated class triangular_matrix<T, F1, F2, A> is the base container adaptor for triangular matrices. For a (n x n )-dimensional lower triangular matrix and 0 <= i < n,0 <= j < n holds ti, j = 0 , if i > j. If furthermore holds ti, i= 1 the matrix is called unit lower triangular. For a (n x n )-dimensional lower triangular matrix and 0 <= i < n,0 <= j < n holds ti, j = 0 , if i < j. If furthermore holds ti, i= 1 the matrix is called unit lower triangular. The storage of triangular matrices is packed.

Example

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

int main () {
    using namespace boost::numeric::ublas;
    triangular_matrix<double, lower> ml (3, 3);
    for (unsigned i = 0; i < ml.size1 (); ++ i)
        for (unsigned j = 0; j <= i; ++ j)
            ml (i, j) = 3 * i + j;
    std::cout << ml << std::endl;
    triangular_matrix<double, upper> mu (3, 3);
    for (unsigned i = 0; i < mu.size1 (); ++ i)
        for (unsigned j = i; j < mu.size2 (); ++ j)
            mu (i, j) = 3 * i + j;
    std::cout << mu << std::endl;
}

Please read the full triangular example for more details.

Definition

Defined in the header triangular.hpp.

Template parameters

Parameter Description Default
T The type of object stored in the matrix.
F1 Functor describing the type of the triangular matrix. [1] lower
F2 Functor describing the storage organization. [2] row_major
A The type of the adapted array. [3] unbounded_array<T>

Model of

Matrix .

Type requirements

None, except for those imposed by the requirements of Matrix .

Public base classes

matrix_container<triangular_matrix<T, F1, F2, A> >

Members

Member Description
triangular_matrix () Allocates an uninitialized triangular_matrix that holds zero rows of zero elements.
triangular_matrix (size_type size1, size_type size2) Allocates an uninitialized triangular_matrix that holds size1 rows of size2 elements.
triangular_matrix (const triangular_matrix &m) The copy constructor.
template<class AE>
triangular_matrix (const matrix_expression<AE> &ae)
The extended copy constructor.
void resize (size_type size1, size_type size2, bool preserve = true) Reallocates a triangular_matrix to hold size1 rows of size2 elements. The existing elements of the triangular_matrix are preseved when specified.
size_type size1 () const Returns the number of rows.
size_type size2 () const Returns the number of columns.
const_reference operator () (size_type i, size_type j) const Returns a const reference of the j -th element in the i-th row.
reference operator () (size_type i, size_type j) Returns a reference of the j-th element in the i-th row.
triangular_matrix &operator = (const triangular_matrix &m) The assignment operator.
triangular_matrix &assign_temporary (triangular_matrix &m) Assigns a temporary. May change the triangular matrix m.
template<class AE>
triangular_matrix &operator = (const matrix_expression<AE> &ae)
The extended assignment operator.
template<class AE>
triangular_matrix &assign (const matrix_expression<AE> &ae)
Assigns a matrix expression to the triangular matrix. Left and right hand side of the assignment should be independent.
template<class AE>
triangular_matrix &operator += (const matrix_expression<AE> &ae)
A computed assignment operator. Adds the matrix expression to the triangular matrix.
template<class AE>
triangular_matrix &plus_assign (const matrix_expression<AE> &ae)
Adds a matrix expression to the triangular matrix. Left and right hand side of the assignment should be independent.
template<class AE>
triangular_matrix &operator -= (const matrix_expression<AE> &ae)
A computed assignment operator. Subtracts the matrix expression from the triangular matrix.
template<class AE>
triangular_matrix &minus_assign (const matrix_expression<AE> &ae)
Subtracts a matrix expression from the triangular matrix. Left and right hand side of the assignment should be independent.
template<class AT>
triangular_matrix &operator *= (const AT &at)
A computed assignment operator. Multiplies the triangular matrix with a scalar.
template<class AT>
triangular_matrix &operator /= (const AT &at)
A computed assignment operator. Divides the triangular matrix through a scalar.
void swap (triangular_matrix &m) Swaps the contents of the triangular matrices.
void insert (size_type i, size_type j, const_reference t) Inserts the value t at the j-th element of the i-th row.
void erase (size_type i, size_type j) Erases the value at the j-th elemenst of the i-th row.
void clear () Clears the matrix.
const_iterator1 begin1 () const Returns a const_iterator1 pointing to the beginning of the triangular_matrix.
const_iterator1 end1 () const Returns a const_iterator1 pointing to the end of the triangular_matrix.
iterator1 begin1 () Returns a iterator1 pointing to the beginning of the triangular_matrix.
iterator1 end1 () Returns a iterator1 pointing to the end of the triangular_matrix.
const_iterator2 begin2 () const Returns a const_iterator2 pointing to the beginning of the triangular_matrix.
const_iterator2 end2 () const Returns a const_iterator2 pointing to the end of the triangular_matrix.
iterator2 begin2 () Returns a iterator2 pointing to the beginning of the triangular_matrix.
iterator2 end2 () Returns a iterator2 pointing to the end of the triangular_matrix.
const_reverse_iterator1 rbegin1 () const Returns a const_reverse_iterator1 pointing to the beginning of the reversed triangular_matrix.
const_reverse_iterator1 rend1 () const Returns a const_reverse_iterator1 pointing to the end of the reversed triangular_matrix.
reverse_iterator1 rbegin1 () Returns a reverse_iterator1 pointing to the beginning of the reversed triangular_matrix.
reverse_iterator1 rend1 () Returns a reverse_iterator1 pointing to the end of the reversed triangular_matrix.
const_reverse_iterator2 rbegin2 () const Returns a const_reverse_iterator2 pointing to the beginning of the reversed triangular_matrix.
const_reverse_iterator2 rend2 () const Returns a const_reverse_iterator2 pointing to the end of the reversed triangular_matrix.
reverse_iterator2 rbegin2 () Returns a reverse_iterator2 pointing to the beginning of the reversed triangular_matrix.
reverse_iterator2 rend2 () Returns a reverse_iterator2 pointing to the end of the reversed triangular_matrix.

Notes

[1] Supported parameters for the type of the triangular matrix are lower , unit_lower, upper and unit_upper .

[2] Supported parameters for the storage organization are row_major and column_major.

[3] Supported parameters for the adapted array are unbounded_array<T> , bounded_array<T> and std::vector<T> .

Triangular Adaptor

Description

The templated class triangular_adaptor<M, F> is a triangular matrix adaptor for other matrices.

Example

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

int main () {
    using namespace boost::numeric::ublas;
    matrix<double> m (3, 3);
    triangular_adaptor<matrix<double>, lower> tal (m);
    for (unsigned i = 0; i < tal.size1 (); ++ i)
        for (unsigned j = 0; j <= i; ++ j)
            tal (i, j) = 3 * i + j;
    std::cout << tal << std::endl;
    triangular_adaptor<matrix<double>, upper> tau (m);
    for (unsigned i = 0; i < tau.size1 (); ++ i)
        for (unsigned j = i; j < tau.size2 (); ++ j)
            tau (i, j) = 3 * i + j;
    std::cout << tau << std::endl;
}

Please read the full triangular example for more details.

Definition

Defined in the header triangular.hpp.

Template parameters

Parameter Description Default
M The type of the adapted matrix.
F Functor describing the type of the triangular adaptor. [1] lower

Model of

Matrix Expression .

Type requirements

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

Public base classes

matrix_expression<triangular_adaptor<M, F> >

Members

Member Description
triangular_adaptor (matrix_type &data) Constructs a triangular_adaptor of a matrix.
triangular_adaptor (const triangular_adaptor &m) The copy constructor.
template<class AE>
triangular_adaptor (const matrix_expression<AE> &ae)
The extended copy constructor.
size_type size1 () const Returns the number of rows.
size_type size2 () const Returns the number of columns.
const_reference operator () (size_type i, size_type j) const Returns a const reference of the j -th element in the i-th row.
reference operator () (size_type i, size_type j) Returns a reference of the j-th element in the i-th row.
triangular_adaptor &operator = (const triangular_adaptor &m) The assignment operator.
triangular_adaptor &assign_temporary (triangular_adaptor &m) Assigns a temporary. May change the triangular adaptor m.
template<class AE>
triangular_adaptor &operator = (const matrix_expression<AE> &ae)
The extended assignment operator.
template<class AE>
triangular_adaptor &assign (const matrix_expression<AE> &ae)
Assigns a matrix expression to the triangular adaptor. Left and right hand side of the assignment should be independent.
template<class AE>
triangular_adaptor &operator += (const matrix_expression<AE> &ae)
A computed assignment operator. Adds the matrix expression to the triangular adaptor.
template<class AE>
triangular_adaptor &plus_assign (const matrix_expression<AE> &ae)
Adds a matrix expression to the triangular adaptor. Left and right hand side of the assignment should be independent.
template<class AE>
triangular_adaptor &operator -= (const matrix_expression<AE> &ae)
A computed assignment operator. Subtracts the matrix expression from the triangular adaptor.
template<class AE>
triangular_adaptor &minus_assign (const matrix_expression<AE> &ae)
Subtracts a matrix expression from the triangular adaptor. Left and right hand side of the assignment should be independent.
template<class AT>
triangular_adaptor &operator *= (const AT &at)
A computed assignment operator. Multiplies the triangular adaptor with a scalar.
template<class AT>
triangular_adaptor &operator /= (const AT &at)
A computed assignment operator. Divides the triangular adaptor through a scalar.
void swap (triangular_adaptor &m) Swaps the contents of the triangular adaptors.
const_iterator1 begin1 () const Returns a const_iterator1 pointing to the beginning of the triangular_adaptor.
const_iterator1 end1 () const Returns a const_iterator1 pointing to the end of the triangular_adaptor.
iterator1 begin1 () Returns a iterator1 pointing to the beginning of the triangular_adaptor.
iterator1 end1 () Returns a iterator1 pointing to the end of the triangular_adaptor.
const_iterator2 begin2 () const Returns a const_iterator2 pointing to the beginning of the triangular_adaptor.
const_iterator2 end2 () const Returns a const_iterator2 pointing to the end of the triangular_adaptor.
iterator2 begin2 () Returns a iterator2 pointing to the beginning of the triangular_adaptor.
iterator2 end2 () Returns a iterator2 pointing to the end of the triangular_adaptor.
const_reverse_iterator1 rbegin1 () const Returns a const_reverse_iterator1 pointing to the beginning of the reversed triangular_adaptor.
const_reverse_iterator1 rend1 () const Returns a const_reverse_iterator1 pointing to the end of the reversed triangular_adaptor.
reverse_iterator1 rbegin1 () Returns a reverse_iterator1 pointing to the beginning of the reversed triangular_adaptor.
reverse_iterator1 rend1 () Returns a reverse_iterator1 pointing to the end of the reversed triangular_adaptor.
const_reverse_iterator2 rbegin2 () const Returns a const_reverse_iterator2 pointing to the beginning of the reversed triangular_adaptor.
const_reverse_iterator2 rend2 () const Returns a const_reverse_iterator2 pointing to the end of the reversed triangular_adaptor.
reverse_iterator2 rbegin2 () Returns a reverse_iterator2 pointing to the beginning of the reversed triangular_adaptor.
reverse_iterator2 rend2 () Returns a reverse_iterator2 pointing to the end of the reversed triangular_adaptor.

Notes

[1] Supported parameters for the type of the triangular adaptor are lower , unit_lower, upper and unit_upper .


Copyright (©) 2000-2002 Joerg Walter, Mathias Koch
Use, modification and distribution are subject to the Boost Software License, Version 1.0. (See accompanying file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt ).