Represents a sequence of transpositions (row/column interchange) More...

#include <Transpositions.h>

Inheritance diagram for Eigen::Transpositions< SizeAtCompileTime, MaxSizeAtCompileTime, IndexType >:

Public Types
typedef TranspositionsBase< Transpositions >	Base

typedef IndicesType::Scalar	Index

typedef Traits::IndicesType	IndicesType

Public Types inherited from Eigen::TranspositionsBase< Transpositions< SizeAtCompileTime, MaxSizeAtCompileTime, IndexType > >
typedef IndicesType::Scalar	Index

typedef Traits::IndicesType	IndicesType

Public Member Functions
const IndicesType &	indices () const

IndicesType &	indices ()

template<typename OtherDerived >
Transpositions &	operator= (const TranspositionsBase< OtherDerived > &other)

Transpositions &	operator= (const Transpositions &other)

	Transpositions ()

template<typename OtherDerived >
	Transpositions (const TranspositionsBase< OtherDerived > &other)

	Transpositions (const Transpositions &other)

template<typename Other >
	Transpositions (const MatrixBase< Other > &a_indices)

	Transpositions (Index size)

Public Member Functions inherited from Eigen::TranspositionsBase< Transpositions< SizeAtCompileTime, MaxSizeAtCompileTime, IndexType > >
const Index &	coeff (Index i) const

Index &	coeffRef (Index i)

Transpositions< SizeAtCompileTime, MaxSizeAtCompileTime, IndexType > &	derived ()

const Transpositions< SizeAtCompileTime, MaxSizeAtCompileTime, IndexType > &	derived () const

const IndicesType &	indices () const

IndicesType &	indices ()

Transpose< TranspositionsBase >	inverse () const

const Index &	operator() (Index i) const

Index &	operator() (Index i)

Transpositions< SizeAtCompileTime, MaxSizeAtCompileTime, IndexType > &	operator= (const TranspositionsBase< OtherDerived > &other)

Transpositions< SizeAtCompileTime, MaxSizeAtCompileTime, IndexType > &	operator= (const TranspositionsBase &other)

const Index &	operator[] (Index i) const

Index &	operator[] (Index i)

void	resize (int newSize)

void	setIdentity ()

Index	size () const

Transpose< TranspositionsBase >	transpose () const

Protected Attributes
IndicesType	m_indices

Private Types
typedef internal::traits< Transpositions >	Traits

Detailed Description

template<int SizeAtCompileTime, int MaxSizeAtCompileTime, typename IndexType>
class Eigen::Transpositions< SizeAtCompileTime, MaxSizeAtCompileTime, IndexType >

Represents a sequence of transpositions (row/column interchange)

Parameters

SizeAtCompileTime	the number of transpositions, or Dynamic
MaxSizeAtCompileTime	the maximum number of transpositions, or Dynamic. This optional parameter defaults to SizeAtCompileTime. Most of the time, you should not have to specify it.

This class represents a permutation transformation as a sequence of n transpositions $[T_{n-1} \ldots T_{i} \ldots T_{0}]$ . It is internally stored as a vector of integers indices. Each transposition $T_{i}$ applied on the left of a matrix ( $T_{i} M$ ) interchanges the rows i and indices[i] of the matrix M. A transposition applied on the right (e.g., $M T_{i}$ ) yields a column interchange.

Compared to the class PermutationMatrix, such a sequence of transpositions is what is computed during a decomposition with pivoting, and it is faster when applying the permutation in-place.

To apply a sequence of transpositions to a matrix, simply use the operator * as in the following example:

Transpositions tr;
MatrixXf mat;
mat = tr * mat;

In this example, we detect that the matrix appears on both side, and so the transpositions are applied in-place without any temporary or extra copy.

See also: class PermutationMatrix

Definition at line 156 of file Transpositions.h.