ILNumerics Ultimate VS

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

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

ExceptionCondition
ArgumentExceptionif A is not square or rangeEnd < rangeStart.
Remarks

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

[ILNumerics Computing Engine]

See Also

Reference