Functions
lapack_int	stev (int matrix_layout, char jobz, lapack_int n, float d, float e, float *z, lapack_int ldz)

lapack_int	stev (int matrix_layout, char jobz, lapack_int n, double d, double e, double *z, lapack_int ldz)

template<typename T >
T	find_mth_eigenvalue (const std::vector< T > &alpha, const std::vector< T > &beta, const size_t index)
	Finds the `m`th smaller eigenvalue of given tridiagonal matrix. More...

template<typename T >
void	tridiagonal_eigenpairs (const std::vector< T > &alpha, const std::vector< T > &beta, std::vector< T > &eigenvalues, std::vector< std::vector< T > > &eigenvectors, bool compute_eigenvector=true)
	Computes all eigenpairs (eigenvalues and eigenvectors) for given tri-diagonal matrix. More...

template<typename T >
void	tridiagonal_eigenvalues (const std::vector< T > &alpha, const std::vector< T > &beta, std::vector< T > &eigenvalues)
	Computes all eigenvalues for given tri-diagonal matrix using the Implicitly Shifted QR algorithm. More...

Function Documentation

◆ find_mth_eigenvalue()

template<typename T >

T lambda_lanczos::tridiagonal_lapack::find_mth_eigenvalue	(	const std::vector< T > &	alpha,
		const std::vector< T > &	beta,
		const size_t	index
	)

inline

Finds the mth smaller eigenvalue of given tridiagonal matrix.

lapack_int lambda_lanczos::tridiagonal_lapack::stev	(	int	matrix_layout,
		char	jobz,
		lapack_int	n,
		double *	d,
		double *	e,
		double *	z,
		lapack_int	ldz
	)

inline

lapack_int lambda_lanczos::tridiagonal_lapack::stev	(	int	matrix_layout,
		char	jobz,
		lapack_int	n,
		float *	d,
		float *	e,
		float *	z,
		lapack_int	ldz
	)

inline

template<typename T >

void lambda_lanczos::tridiagonal_lapack::tridiagonal_eigenpairs	(	const std::vector< T > &	alpha,
		const std::vector< T > &	beta,
		std::vector< T > &	eigenvalues,
		std::vector< std::vector< T > > &	eigenvectors,
		bool	compute_eigenvector = `true`
	)

inline

Computes all eigenpairs (eigenvalues and eigenvectors) for given tri-diagonal matrix.

template<typename T >

void lambda_lanczos::tridiagonal_lapack::tridiagonal_eigenvalues	(	const std::vector< T > &	alpha,
		const std::vector< T > &	beta,
		std::vector< T > &	eigenvalues
	)

inline

Computes all eigenvalues for given tri-diagonal matrix using the Implicitly Shifted QR algorithm.

Parameters

[in]	alpha	Diagonal elements of the full tridiagonal matrix.
[in]	beta	Sub-diagonal elements of the full tridiagonal matrix.
[out]	eigenvalues	Eigenvalues.