# Sparse Matrix

#### Description

The templated class `sparse_matrix<T, F, A>` is the base container adaptor for sparse matrices. For a (m x n)-dimensional sparse matrix and 0 <= i < m, 0 <= j < n the non-zero elements mi, j are mapped via (i x n + j) for row major orientation or via (i + j x m) for column major orientation to consecutive elements of the associative container, i.e. for elements k = mi1 ,j1and k + 1 = mi2 ,j2of the container holds i1 < i2 or (i1 = i2 and j1 < j2) with row major orientation or j1 < j2 or (j1 = j2 and i1 < i2) with column major orientation.

#### Example

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

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

    int main () {

        using namespace boost::numeric::ublas;

        sparse_matrix<double> m (3, 3, 3 * 3);

        for (unsigned i = 0; i < m.size1 (); ++ i)

            for (unsigned j = 0; j < m.size2 (); ++ j)

                m (i, j) = 3 * i + j;

        std::cout << m << std::endl;

    }

#### Definition

Defined in the header matrix_sparse.hpp.

#### Template parameters

Parameter | Description | Default
--- | --- | ---
`T` | The type of object stored in the sparse matrix. |
`F` | Functor describing the storage organization. [1] | `row_major`
`A` | The type of the adapted array. [2] | `map_array<std::size_t, T>`

#### Model of

Matrix .

#### Type requirements

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

#### Public base classes

`matrix_expression<sparse_matrix<T, F, A> >`

#### Members

Member | Description
--- | ---
`sparse_matrix ()` | Allocates a `sparse_matrix` that holds at most zero rows of zero elements.
`sparse_matrix (size_type size1, size_type2, size_type non_zeros)` | Allocates a `sparse_matrix` that holds at most `size1` rows of `size2` elements.
`sparse_matrix (const sparse_matrix &m)` | The copy constructor.
`template<class AE> sparse_matrix (size_type non_zeros, const matrix_expression<AE> &ae)` | The extended copy constructor.
`void resize (size_type size1, size_type size2, size_type non_zeros)` | Reallocates a `sparse_matrix` to hold at most `size1` rows of `size2` elements. The content of the `sparse_matrix` is preserved.
`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 the value 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.
`sparse_matrix &operator = (const sparse_matrix &m)` | The assignment operator.
`sparse_matrix &assign_temporary (sparse_matrix &m)` | Assigns a temporary. May change the sparse matrix `m` .
`template<class AE> sparse_matrix &operator = (const matrix_expression<AE> &ae)` | The extended assignment operator.
`template<class AE> sparse_matrix &assign (const matrix_expression<AE> &ae)` | Assigns a matrix expression to the sparse matrix. Left and right hand side of the assignment should be independent.
`template<class AE> sparse_matrix &operator += (const matrix_expression<AE> &ae)` | A computed assignment operator. Adds the matrix expression to the sparse matrix.
`template<class AE> sparse_matrix &plus_assign (const matrix_expression<AE> &ae)` | Adds a matrix expression to the sparse matrix. Left and right hand side of the assignment should be independent.
`template<class AE> sparse_matrix &operator -= (const matrix_expression<AE> &ae)` | A computed assignment operator. Subtracts the matrix expression from the sparse matrix.
`template<class AE> sparse_matrix &minus_assign (const matrix_expression<AE> &ae)` | Subtracts a matrix expression from the sparse matrix. Left and right hand side of the assignment should be independent.
`template<class AT> sparse_matrix &operator *= (const AT &at)` | A computed assignment operator. Multiplies the sparse matrix with a scalar.
`template<class AT> sparse_matrix &operator /= (const AT &at)` | A computed assignment operator. Divides the sparse matrix through a scalar.
`void swap (sparse_matrix &m)` | Swaps the contents of the sparse 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 element of the `i`-th row.
`void clear ()` | Clears the sparse matrix.
`const_iterator1 begin1 () const` | Returns a `const_iterator1` pointing to the beginning of the `sparse_matrix`.
`const_iterator1 end1 () const` | Returns a `const_iterator1` pointing to the end of the `sparse_matrix`.
`iterator1 begin1 ()` | Returns a `iterator1` pointing to the beginning of the `sparse_matrix`.
`iterator1 end1 ()` | Returns a `iterator1` pointing to the end of the `sparse_matrix`.
`const_iterator2 begin2 () const` | Returns a `const_iterator2` pointing to the beginning of the `sparse_matrix`.
`const_iterator2 end2 () const` | Returns a `const_iterator2` pointing to the end of the `sparse_matrix`.
`iterator2 begin2 ()` | Returns a `iterator2` pointing to the beginning of the `sparse_matrix`.
`iterator2 end2 ()` | Returns a `iterator2` pointing to the end of the `sparse_matrix`.
`const_reverse_iterator1 rbegin1 () const` | Returns a `const_reverse_iterator1` pointing to the beginning of the reversed `sparse_matrix`.
`const_reverse_iterator1 rend1 () const` | Returns a `const_reverse_iterator1` pointing to the end of the reversed `sparse_matrix`.
`reverse_iterator1 rbegin1 ()` | Returns a `reverse_iterator1` pointing to the beginning of the reversed `sparse_matrix`.
`reverse_iterator1 rend1 ()` | Returns a `reverse_iterator1` pointing to the end of the reversed `sparse_matrix`.
`const_reverse_iterator2 rbegin2 () const` | Returns a `const_reverse_iterator2` pointing to the beginning of the reversed `sparse_matrix`.
`const_reverse_iterator2 rend2 () const` | Returns a `const_reverse_iterator2` pointing to the end of the reversed `sparse_matrix`.
`reverse_iterator2 rbegin2 ()` | Returns a `reverse_iterator2` pointing to the beginning of the reversed `sparse_matrix`.
`reverse_iterator2 rend2 ()` | Returns a `reverse_iterator2` pointing to the end of the reversed `sparse_matrix`.

#### Notes

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

[2] Supported parameters for the adapted array are `map_array<std::size_t, T>` and `std::map<std::size_t, T>`.

## Compressed Matrix

#### Description

The templated class `compressed_matrix<T, F, IB, IA, TA>` is the base container adaptor for compressed matrices. For a (m x n )-dimensional compressed matrix and 0 <= i < m, 0 <= j < n the non-zero elements mi, j are mapped via (i x n + j) for row major orientation or via (i + j x m) for column major orientation to consecutive elements of the index and value containers, i.e. for elements k = mi1 ,j1and k + 1 = mi2 ,j2of the container holds i1 < i2 or (i1 = i2 and j1 < j2) with row major orientation or j1 < j2 or (j1 = j2 and i1 < i2) with column major orientation.

#### Example

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

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

    int main () {

        using namespace boost::numeric::ublas;

        compressed_matrix<double> m (3, 3, 3 * 3);

        for (unsigned i = 0; i < m.size1 (); ++ i)

            for (unsigned j = 0; j < m.size2 (); ++ j)

                m (i, j) = 3 * i + j;

        std::cout << m << std::endl;

    }

#### Definition

Defined in the header matrix_sparse.hpp.

#### Template parameters

Parameter | Description | Default
--- | --- | ---
`T` | The type of object stored in the compressed matrix. |
`F` | Functor describing the storage organization. [1] | `row_major`
`IB` | The index base of the compressed vector. [2] | `0`
`IA` | The type of the adapted array for indices. [3] | `unbounded_array<std::size_t>`
`TA` | The type of the adapted array for values. [3] | `unbounded_array<T>`

#### Model of

Matrix .

#### Type requirements

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

#### Public base classes

`matrix_expression<compressed_matrix<T, F, IB, IA, TA> >`

#### Members

Member | Description
--- | ---
`compressed_matrix ()` | Allocates a `compressed_matrix` that holds at most zero rows of zero elements.
`compressed_matrix (size_type size1, size_type2, size_type non_zeros)` | Allocates a `compressed_matrix` that holds at most `size1` rows of `size2` elements.
`compressed_matrix (const compressed_matrix &m)` | The copy constructor.
`template<class AE> compressed_matrix (size_type non_zeros, const matrix_expression<AE> &ae)` | The extended copy constructor.
`void resize (size_type size1, size_type size2, size_type non_zeros)` | Reallocates a `compressed_matrix` to hold at most `size1` rows of `size2` elements. The content of the `compressed_matrix` is preserved.
`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 the value 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.
`compressed_matrix &operator = (const compressed_matrix &m)` | The assignment operator.
`compressed_matrix &assign_temporary (compressed_matrix &m)` | Assigns a temporary. May change the compressed matrix `m`.
`template<class AE> compressed_matrix &operator = (const matrix_expression<AE> &ae)` | The extended assignment operator.
`template<class AE> compressed_matrix &assign (const matrix_expression<AE> &ae)` | Assigns a matrix expression to the compressed matrix. Left and right hand side of the assignment should be independent.
`template<class AE> compressed_matrix &operator += (const matrix_expression<AE> &ae)` | A computed assignment operator. Adds the matrix expression to the compressed matrix.
`template<class AE> compressed_matrix &plus_assign (const matrix_expression<AE> &ae)` | Adds a matrix expression to the compressed matrix. Left and right hand side of the assignment should be independent.
`template<class AE> compressed_matrix &operator -= (const matrix_expression<AE> &ae)` | A computed assignment operator. Subtracts the matrix expression from the compressed matrix.
`template<class AE> compressed_matrix &minus_assign (const matrix_expression<AE> &ae)` | Subtracts a matrix expression from the compressed matrix. Left and right hand side of the assignment should be independent.
`template<class AT> compressed_matrix &operator *= (const AT &at)` | A computed assignment operator. Multiplies the compressed matrix with a scalar.
`template<class AT> compressed_matrix &operator /= (const AT &at)` | A computed assignment operator. Divides the compressed matrix through a scalar.
`void swap (compressed_matrix &m)` | Swaps the contents of the compressed 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 element of the `i`-th row.
`void clear ()` | Clears the compressed matrix.
`const_iterator1 begin1 () const` | Returns a `const_iterator1` pointing to the beginning of the `compressed_matrix`.
`const_iterator1 end1 () const` | Returns a `const_iterator1` pointing to the end of the `compressed_matrix`.
`iterator1 begin1 ()` | Returns a `iterator1` pointing to the beginning of the `compressed_matrix`.
`iterator1 end1 ()` | Returns a `iterator1` pointing to the end of the `compressed_matrix`.
`const_iterator2 begin2 () const` | Returns a `const_iterator2` pointing to the beginning of the `compressed_matrix`.
`const_iterator2 end2 () const` | Returns a `const_iterator2` pointing to the end of the `compressed_matrix`.
`iterator2 begin2 ()` | Returns a `iterator2` pointing to the beginning of the `compressed_matrix`.
`iterator2 end2 ()` | Returns a `iterator2` pointing to the end of the `compressed_matrix`.
`const_reverse_iterator1 rbegin1 () const` | Returns a `const_reverse_iterator1` pointing to the beginning of the reversed `compressed_matrix`.
`const_reverse_iterator1 rend1 () const` | Returns a `const_reverse_iterator1` pointing to the end of the reversed `compressed_matrix`.
`reverse_iterator1 rbegin1 ()` | Returns a `reverse_iterator1` pointing to the beginning of the reversed `compressed_matrix`.
`reverse_iterator1 rend1 ()` | Returns a `reverse_iterator1` pointing to the end of the reversed `compressed_matrix`.
`const_reverse_iterator2 rbegin2 () const` | Returns a `const_reverse_iterator2` pointing to the beginning of the reversed `compressed_matrix`.
`const_reverse_iterator2 rend2 () const` | Returns a `const_reverse_iterator2` pointing to the end of the reversed `compressed_matrix`.
`reverse_iterator2 rbegin2 ()` | Returns a `reverse_iterator2` pointing to the beginning of the reversed `compressed_matrix`.
`reverse_iterator2 rend2 ()` | Returns a `reverse_iterator2` pointing to the end of the reversed `compressed_matrix`.

#### Notes

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

[2] Supported parameters for the index base are `0` and `1` at least.

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

## Coordinate Matrix

#### Description

The templated class `coordinate_matrix<T, F, IB, IA, TA>` is the base container adaptor for compressed matrices. For a (m x n )-dimensional sorted coordinate matrix and 0 <= i < m, 0 <= j < n the non-zero elements mi, j are mapped via (i x n + j) for row major orientation or via (i + j x m) for column major orientation to consecutive elements of the index and value containers, i.e. for elements k = mi1 ,j1and k + 1 = mi2 ,j2of the container holds i1 < i2 or (i1 = i2 and j1 < j2) with row major orientation or j1 < j2 or (j1 = j2 and i1 < i2) with column major orientation.

#### Example

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

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

    int main () {

        using namespace boost::numeric::ublas;

        coordinate_matrix<double> m (3, 3, 3 * 3);

        for (unsigned i = 0; i < m.size1 (); ++ i)

            for (unsigned j = 0; j < m.size2 (); ++ j)

                m (i, j) = 3 * i + j;

        std::cout << m << std::endl;

    }

#### Definition

Defined in the header matrix_sparse.hpp.

#### Template parameters

Parameter | Description | Default
--- | --- | ---
`T` | The type of object stored in the coordinate matrix. |
`F` | Functor describing the storage organization. [1] | `row_major`
`IB` | The index base of the coordinate vector. [2] | `0`
`IA` | The type of the adapted array for indices. [3] | `unbounded_array<std::size_t>`
`TA` | The type of the adapted array for values. [3] | `unbounded_array<T>`

#### Model of

Matrix .

#### Type requirements

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

#### Public base classes

`matrix_expression<coordinate_matrix<T, F, IB, IA, TA> >`

#### Members

Member | Description
--- | ---
`coordinate_matrix ()` | Allocates a `coordinate_matrix` that holds at most zero rows of zero elements.
`coordinate_matrix (size_type size1, size_type2, size_type non_zeros)` | Allocates a `coordinate_matrix` that holds at most `size1` rows of `size2` elements.
`coordinate_matrix (const coordinate_matrix &m)` | The copy constructor.
`template<class AE> coordinate_matrix (size_type non_zeros, const matrix_expression<AE> &ae)` | The extended copy constructor.
`void resize (size_type size1, size_type size2, size_type non_zeros)` | Reallocates a `coordinate_matrix` to hold at most `size1` rows of `size2` elements. The content of the `coordinate_matrix` is preserved.
`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 the value 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.
`coordinate_matrix &operator = (const coordinate_matrix &m)` | The assignment operator.
`coordinate_matrix &assign_temporary (coordinate_matrix &m)` | Assigns a temporary. May change the coordinate matrix `m`.
`template<class AE> coordinate_matrix &operator = (const matrix_expression<AE> &ae)` | The extended assignment operator.
`template<class AE> coordinate_matrix &assign (const matrix_expression<AE> &ae)` | Assigns a matrix expression to the coordinate matrix. Left and right hand side of the assignment should be independent.
`template<class AE> coordinate_matrix &operator += (const matrix_expression<AE> &ae)` | A computed assignment operator. Adds the matrix expression to the coordinate matrix.
`template<class AE> coordinate_matrix &plus_assign (const matrix_expression<AE> &ae)` | Adds a matrix expression to the coordinate matrix. Left and right hand side of the assignment should be independent.
`template<class AE> coordinate_matrix &operator -= (const matrix_expression<AE> &ae)` | A computed assignment operator. Subtracts the matrix expression from the coordinate matrix.
`template<class AE> coordinate_matrix &minus_assign (const matrix_expression<AE> &ae)` | Subtracts a matrix expression from the coordinate matrix. Left and right hand side of the assignment should be independent.
`template<class AT> coordinate_matrix &operator *= (const AT &at)` | A computed assignment operator. Multiplies the coordinate matrix with a scalar.
`template<class AT> coordinate_matrix &operator /= (const AT &at)` | A computed assignment operator. Divides the coordinate matrix through a scalar.
`void swap (coordinate_matrix &m)` | Swaps the contents of the coordinate 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 element of the `i`-th row.
`void clear ()` | Clears the coordinate matrix.
`const_iterator1 begin1 () const` | Returns a `const_iterator1` pointing to the beginning of the `coordinate_matrix`.
`const_iterator1 end1 () const` | Returns a `const_iterator1` pointing to the end of the `coordinate_matrix`.
`iterator1 begin1 ()` | Returns a `iterator1` pointing to the beginning of the `coordinate_matrix`.
`iterator1 end1 ()` | Returns a `iterator1` pointing to the end of the `coordinate_matrix`.
`const_iterator2 begin2 () const` | Returns a `const_iterator2` pointing to the beginning of the `coordinate_matrix`.
`const_iterator2 end2 () const` | Returns a `const_iterator2` pointing to the end of the `coordinate_matrix`.
`iterator2 begin2 ()` | Returns a `iterator2` pointing to the beginning of the `coordinate_matrix`.
`iterator2 end2 ()` | Returns a `iterator2` pointing to the end of the `coordinate_matrix`.
`const_reverse_iterator1 rbegin1 () const` | Returns a `const_reverse_iterator1` pointing to the beginning of the reversed `coordinate_matrix`.
`const_reverse_iterator1 rend1 () const` | Returns a `const_reverse_iterator1` pointing to the end of the reversed `coordinate_matrix`.
`reverse_iterator1 rbegin1 ()` | Returns a `reverse_iterator1` pointing to the beginning of the reversed `coordinate_matrix`.
`reverse_iterator1 rend1 ()` | Returns a `reverse_iterator1` pointing to the end of the reversed `coordinate_matrix`.
`const_reverse_iterator2 rbegin2 () const` | Returns a `const_reverse_iterator2` pointing to the beginning of the reversed `coordinate_matrix`.
`const_reverse_iterator2 rend2 () const` | Returns a `const_reverse_iterator2` pointing to the end of the reversed `coordinate_matrix`.
`reverse_iterator2 rbegin2 ()` | Returns a `reverse_iterator2` pointing to the beginning of the reversed `coordinate_matrix`.
`reverse_iterator2 rend2 ()` | Returns a `reverse_iterator2` pointing to the end of the reversed `coordinate_matrix`.

#### Notes

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

[2] Supported parameters for the index base are `0` and `1` at least.

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

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