Performs a complex Schur decomposition of a real or complex square matrix. More...
#include <ComplexSchur.h>
Public Types | |
enum | { RowsAtCompileTime = MatrixType::RowsAtCompileTime, ColsAtCompileTime = MatrixType::ColsAtCompileTime, Options = MatrixType::Options, MaxRowsAtCompileTime = MatrixType::MaxRowsAtCompileTime, MaxColsAtCompileTime = MatrixType::MaxColsAtCompileTime } |
typedef Matrix< ComplexScalar, RowsAtCompileTime, ColsAtCompileTime, Options, MaxRowsAtCompileTime, MaxColsAtCompileTime > | ComplexMatrixType |
Type for the matrices in the Schur decomposition. | |
typedef std::complex< RealScalar > | ComplexScalar |
Complex scalar type for _MatrixType . | |
typedef MatrixType::Index | Index |
typedef _MatrixType | MatrixType |
typedef NumTraits< Scalar >::Real | RealScalar |
typedef MatrixType::Scalar | Scalar |
Scalar type for matrices of type _MatrixType . | |
Public Member Functions | |
ComplexSchur (Index size=RowsAtCompileTime==Dynamic?1:RowsAtCompileTime) | |
Default constructor. | |
ComplexSchur (const MatrixType &matrix, bool computeU=true) | |
Constructor; computes Schur decomposition of given matrix. | |
ComplexSchur & | compute (const MatrixType &matrix, bool computeU=true) |
Computes Schur decomposition of given matrix. | |
ComputationInfo | info () const |
Reports whether previous computation was successful. | |
const ComplexMatrixType & | matrixT () const |
Returns the triangular matrix in the Schur decomposition. | |
const ComplexMatrixType & | matrixU () const |
Returns the unitary matrix in the Schur decomposition. | |
Static Public Attributes | |
static const int | m_maxIterations = 30 |
Maximum number of iterations. | |
Protected Attributes | |
HessenbergDecomposition < MatrixType > | m_hess |
ComputationInfo | m_info |
bool | m_isInitialized |
ComplexMatrixType | m_matT |
ComplexMatrixType | m_matU |
bool | m_matUisUptodate |
Private Member Functions | |
ComplexScalar | computeShift (Index iu, Index iter) |
void | reduceToTriangularForm (bool computeU) |
bool | subdiagonalEntryIsNeglegible (Index i) |
Friends | |
struct | internal::complex_schur_reduce_to_hessenberg< MatrixType, NumTraits< Scalar >::IsComplex > |
Performs a complex Schur decomposition of a real or complex square matrix.
_MatrixType | the type of the matrix of which we are computing the Schur decomposition; this is expected to be an instantiation of the Matrix class template. |
Given a real or complex square matrix A, this class computes the Schur decomposition: where U is a unitary complex matrix, and T is a complex upper triangular matrix. The diagonal of the matrix T corresponds to the eigenvalues of the matrix A.
Call the function compute() to compute the Schur decomposition of a given matrix. Alternatively, you can use the ComplexSchur(const MatrixType&, bool) constructor which computes the Schur decomposition at construction time. Once the decomposition is computed, you can use the matrixU() and matrixT() functions to retrieve the matrices U and V in the decomposition.
Definition at line 51 of file ComplexSchur.h.
typedef Matrix<ComplexScalar, RowsAtCompileTime, ColsAtCompileTime, Options, MaxRowsAtCompileTime, MaxColsAtCompileTime> Eigen::ComplexSchur< _MatrixType >::ComplexMatrixType |
Type for the matrices in the Schur decomposition.
This is a square matrix with entries of type ComplexScalar. The size is the same as the size of _MatrixType
.
Definition at line 81 of file ComplexSchur.h.
typedef std::complex<RealScalar> Eigen::ComplexSchur< _MatrixType >::ComplexScalar |
Complex scalar type for _MatrixType
.
This is std::complex<Scalar>
if Scalar is real (e.g., float
or double
) and just Scalar
if Scalar is complex.
Definition at line 74 of file ComplexSchur.h.
typedef MatrixType::Index Eigen::ComplexSchur< _MatrixType >::Index |
Definition at line 66 of file ComplexSchur.h.
typedef _MatrixType Eigen::ComplexSchur< _MatrixType >::MatrixType |
Definition at line 54 of file ComplexSchur.h.
typedef NumTraits<Scalar>::Real Eigen::ComplexSchur< _MatrixType >::RealScalar |
Definition at line 65 of file ComplexSchur.h.
typedef MatrixType::Scalar Eigen::ComplexSchur< _MatrixType >::Scalar |
Scalar type for matrices of type _MatrixType
.
Definition at line 64 of file ComplexSchur.h.
anonymous enum |
Definition at line 55 of file ComplexSchur.h.
Eigen::ComplexSchur< _MatrixType >::ComplexSchur | ( | Index | size = RowsAtCompileTime==Dynamic ? 1 : RowsAtCompileTime | ) | [inline] |
Default constructor.
[in] | size | Positive integer, size of the matrix whose Schur decomposition will be computed. |
The default constructor is useful in cases in which the user intends to perform decompositions via compute(). The size
parameter is only used as a hint. It is not an error to give a wrong size
, but it may impair performance.
Definition at line 94 of file ComplexSchur.h.
Eigen::ComplexSchur< _MatrixType >::ComplexSchur | ( | const MatrixType & | matrix, |
bool | computeU = true |
||
) | [inline] |
Constructor; computes Schur decomposition of given matrix.
[in] | matrix | Square matrix whose Schur decomposition is to be computed. |
[in] | computeU | If true, both T and U are computed; if false, only T is computed. |
This constructor calls compute() to compute the Schur decomposition.
Definition at line 111 of file ComplexSchur.h.
ComplexSchur< MatrixType > & Eigen::ComplexSchur< MatrixType >::compute | ( | const MatrixType & | matrix, |
bool | computeU = true |
||
) |
Computes Schur decomposition of given matrix.
[in] | matrix | Square matrix whose Schur decomposition is to be computed. |
[in] | computeU | If true, both T and U are computed; if false, only T is computed. |
*this
The Schur decomposition is computed by first reducing the matrix to Hessenberg form using the class HessenbergDecomposition. The Hessenberg matrix is then reduced to triangular form by performing QR iterations with a single shift. The cost of computing the Schur decomposition depends on the number of iterations; as a rough guide, it may be taken on the number of iterations; as a rough guide, it may be taken to be complex flops, or complex flops if computeU is false.
Example:
Output:
Definition at line 271 of file ComplexSchur.h.
ComplexSchur< MatrixType >::ComplexScalar Eigen::ComplexSchur< MatrixType >::computeShift | ( | Index | iu, |
Index | iter | ||
) | [private] |
Compute the shift in the current QR iteration.
Definition at line 235 of file ComplexSchur.h.
ComputationInfo Eigen::ComplexSchur< _MatrixType >::info | ( | ) | const [inline] |
Reports whether previous computation was successful.
Success
if computation was succesful, NoConvergence
otherwise. Definition at line 190 of file ComplexSchur.h.
const ComplexMatrixType& Eigen::ComplexSchur< _MatrixType >::matrixT | ( | ) | const [inline] |
Returns the triangular matrix in the Schur decomposition.
It is assumed that either the constructor ComplexSchur(const MatrixType& matrix, bool computeU) or the member function compute(const MatrixType& matrix, bool computeU) has been called before to compute the Schur decomposition of a matrix.
Note that this function returns a plain square matrix. If you want to reference only the upper triangular part, use:
schur.matrixT().triangularView<Upper>()
Example:
Output:
Definition at line 159 of file ComplexSchur.h.
const ComplexMatrixType& Eigen::ComplexSchur< _MatrixType >::matrixU | ( | ) | const [inline] |
Returns the unitary matrix in the Schur decomposition.
It is assumed that either the constructor ComplexSchur(const MatrixType& matrix, bool computeU) or the member function compute(const MatrixType& matrix, bool computeU) has been called before to compute the Schur decomposition of a matrix, and that computeU
was set to true (the default value).
Example:
Output:
Definition at line 135 of file ComplexSchur.h.
void Eigen::ComplexSchur< MatrixType >::reduceToTriangularForm | ( | bool | computeU | ) | [private] |
Definition at line 330 of file ComplexSchur.h.
bool Eigen::ComplexSchur< MatrixType >::subdiagonalEntryIsNeglegible | ( | Index | i | ) | [inline, private] |
If m_matT(i+1,i) is neglegible in floating point arithmetic compared to m_matT(i,i) and m_matT(j,j), then set it to zero and return true, else return false.
Definition at line 220 of file ComplexSchur.h.
friend struct internal::complex_schur_reduce_to_hessenberg< MatrixType, NumTraits< Scalar >::IsComplex > [friend] |
Definition at line 213 of file ComplexSchur.h.
HessenbergDecomposition<MatrixType> Eigen::ComplexSchur< _MatrixType >::m_hess [protected] |
Definition at line 204 of file ComplexSchur.h.
ComputationInfo Eigen::ComplexSchur< _MatrixType >::m_info [protected] |
Definition at line 205 of file ComplexSchur.h.
bool Eigen::ComplexSchur< _MatrixType >::m_isInitialized [protected] |
Definition at line 206 of file ComplexSchur.h.
ComplexMatrixType Eigen::ComplexSchur< _MatrixType >::m_matT [protected] |
Definition at line 203 of file ComplexSchur.h.
ComplexMatrixType Eigen::ComplexSchur< _MatrixType >::m_matU [protected] |
Definition at line 203 of file ComplexSchur.h.
bool Eigen::ComplexSchur< _MatrixType >::m_matUisUptodate [protected] |
Definition at line 207 of file ComplexSchur.h.
const int Eigen::ComplexSchur< _MatrixType >::m_maxIterations = 30 [static] |
Maximum number of iterations.
Maximum number of iterations allowed for an eigenvalue to converge.
Definition at line 200 of file ComplexSchur.h.