ILMatheigSymm Method (InArrayDouble, OutArrayDouble, Int32, Int32)

ILNumerics Ultimate VS Documentation

ILNumerics - Technical Application Development

Find some eigenvalues and -vectors of symmetric (hermitian) matrix. Filter by (1 based) index of eigenvalues.

[ILNumerics Computing Engine]

Namespace: ILNumerics
Assembly: ILNumerics.Computing (in ILNumerics.Computing.dll) Version: 5.5.0.0 (5.5.7503.3146)

Syntax

Copy

public static RetArray<double> eigSymm(
	InArray<double> A,
	OutArray<double> V,
	int rangeStart,
	int rangeEnd
)

Public Shared Function eigSymm ( 
	A As InArray(Of Double),
	V As OutArray(Of Double),
	rangeStart As Integer,
	rangeEnd As Integer
) As RetArray(Of Double)

Dim A As InArray(Of Double)
Dim V As OutArray(Of Double)
Dim rangeStart As Integer
Dim rangeEnd As Integer
Dim returnValue As RetArray(Of Double)

returnValue = ILMath.eigSymm(A, V, rangeStart, 
	rangeEnd)

Parameters

A: Type: ILNumericsInArrayDouble
Input matrix, Size [n x n], symmetric (hermitian for complex A).
V: Type: ILNumericsOutArrayDouble
Output: m eigenvectors as columns. Size [n x m]. If V is null on input the eigenvectors will not be computed.
rangeStart: Type: SystemInt32
Determines the lower limit of the index range of eigenvalues to be returned.
rangeEnd: Type: SystemInt32
Determines the upper limit of the index range of eigenvalues to be returned.

Return Value

Type: RetArrayDouble
Diagonal matrix of size [n,m] with eigenvalues of A on the main diagonal if V is requested. Otherwise a vector with the first m elements being the requested eigenvalues.

Exceptions

Exception	Condition
ArgumentException	if A is not square or rangeEnd < rangeStart.

Remarks

For computation the Lapack functions dsyevr, ssyevr, chesvr and zheesv are used.

[ILNumerics Computing Engine]

Reference

ILMath Class

eigSymm Overload

ILNumerics Namespace