Represents a sequence of transpositions (row/column interchange). More...
Inherits Eigen::TranspositionsBase< Transpositions< SizeAtCompileTime, MaxSizeAtCompileTime, IndexType > >.
Public Member Functions | |
const IndicesType & | indices () const |
IndicesType & | indices () |
template<typename OtherDerived > | |
Transpositions & | operator= (const TranspositionsBase< OtherDerived > &other) |
Transpositions (Index size) | |
template<typename OtherDerived > | |
Transpositions (const TranspositionsBase< OtherDerived > &other) | |
template<typename Other > | |
Transpositions (const MatrixBase< Other > &indices) |
Represents a sequence of transpositions (row/column interchange).
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 . It is internally stored as a vector of integers
indices
. Each transposition applied on the left of a matrix (
) interchanges the rows
i
and indices
[i] of the matrix M
. A transposition applied on the right (e.g., ) 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.
Transpositions | ( | const TranspositionsBase< OtherDerived > & | other | ) | [inline] |
Copy constructor.
Transpositions | ( | const MatrixBase< Other > & | indices | ) | [inline, explicit] |
Generic constructor from expression of the transposition indices.
Transpositions | ( | Index | size | ) | [inline] |
Constructs an uninitialized permutation matrix of given size.
const IndicesType& indices | ( | ) | const [inline] |
const version of indices().
IndicesType& indices | ( | ) | [inline] |
Transpositions& operator= | ( | const TranspositionsBase< OtherDerived > & | other | ) | [inline] |
Copies the other transpositions into *this