ManagedLapackOfSingle.SymmetricTridiagonalEigenvalueDecompose Method

public override void SymmetricTridiagonalEigenvalueDecompose(
	char compz,
	int n,
	Span<float> d,
	Span<float> e,
	Span<float> z,
	int ldz,
	out int info
)

Public Overrides Sub SymmetricTridiagonalEigenvalueDecompose ( 
	compz As Char,
	n As Integer,
	d As Span(Of Single),
	e As Span(Of Single),
	z As Span(Of Single),
	ldz As Integer,
	<OutAttribute> ByRef info As Integer
)

public:
virtual void SymmetricTridiagonalEigenvalueDecompose(
	wchar_t compz, 
	int n, 
	Span<float> d, 
	Span<float> e, 
	Span<float> z, 
	int ldz, 
	[OutAttribute] int% info
) override

abstract SymmetricTridiagonalEigenvalueDecompose : 
        compz : char * 
        n : int * 
        d : Span<float32> * 
        e : Span<float32> * 
        z : Span<float32> * 
        ldz : int * 
        info : int byref -> unit 
override SymmetricTridiagonalEigenvalueDecompose : 
        compz : char * 
        n : int * 
        d : Span<float32> * 
        e : Span<float32> * 
        z : Span<float32> * 
        ldz : int * 
        info : int byref -> unit 

Parameters

compz  Char

COMPZ is CHARACTER*1 = 'N': Compute eigenvalues only. = 'V': Compute eigenvalues and eigenvectors of the original symmetric matrix. On entry, Z must contain the orthogonal matrix used to reduce the original matrix to tridiagonal form. = 'I': Compute eigenvalues and eigenvectors of the tridiagonal matrix. Z is initialized to the identity matrix.

n  Int32

N is INTEGER The order of the matrix. N >= 0.

d  Span<Single>

D is DOUBLE PRECISION array, dimension (N) On entry, the diagonal elements of the tridiagonal matrix. On exit, if INFO = 0, the eigenvalues in ascending order.

e  Span<Single>

E is DOUBLE PRECISION array, dimension (N-1) On entry, the (n-1) subdiagonal elements of the tridiagonal matrix. On exit, E has been destroyed.

z  Span<Single>

Z is DOUBLE PRECISION array, dimension (LDZ, N) On entry, if COMPZ = 'V', then Z contains the orthogonal matrix used in the reduction to tridiagonal form. On exit, if INFO = 0, then if COMPZ = 'V', Z contains the orthonormal eigenvectors of the original symmetric matrix, and if COMPZ = 'I', Z contains the orthonormal eigenvectors of the symmetric tridiagonal matrix. If COMPZ = 'N', then Z is not referenced.

ldz  Int32

LDZ is INTEGER The leading dimension of the array Z. LDZ >= 1, and if eigenvectors are desired, then LDZ >= max(1,N).

info  Int32

INFO is INTEGER = 0: successful exit < 0: if INFO = -i, the i-th argument had an illegal value > 0: the algorithm has failed to find all the eigenvalues in a total of 30*N iterations; if INFO = i, then i elements of E have not converged to zero; on exit, D and E contain the elements of a symmetric tridiagonal matrix which is orthogonally similar to the original matrix.

The eigenvectors of a full or band symmetric matrix can also be found if DSYTRD or DSPTRD or DSBTRD has been used to reduce this matrix to tridiagonal form.

Authors: Univ. of Tennessee, Univ. of California Berkeley, Univ. of Colorado Denver, NAG Ltd.

Reference