DSYEVRun Method

public void Run(
	string JOBZ,
	string UPLO,
	int N,
	ref double[] A,
	int offset_a,
	int LDA,
	ref double[] W,
	int offset_w,
	ref double[] WORK,
	int offset_work,
	int LWORK,
	ref int INFO
)

Public Sub Run ( 
	JOBZ As String,
	UPLO As String,
	N As Integer,
	ByRef A As Double(),
	offset_a As Integer,
	LDA As Integer,
	ByRef W As Double(),
	offset_w As Integer,
	ByRef WORK As Double(),
	offset_work As Integer,
	LWORK As Integer,
	ByRef INFO As Integer
)

Parameters

JOBZ  String

(input) CHARACTER*1 = 'N': Compute eigenvalues only; = 'V': Compute eigenvalues and eigenvectors.

UPLO  String

(input) CHARACTER*1 = 'U': Upper triangle of A is stored; = 'L': Lower triangle of A is stored.

N  Int32

(input) INTEGER The order of the matrix A. N .GE. 0.

A  Double

(input/output) DOUBLE PRECISION array, dimension (LDA, N) On entry, the symmetric matrix A. If UPLO = 'U', the leading N-by-N upper triangular part of A contains the upper triangular part of the matrix A. If UPLO = 'L', the leading N-by-N lower triangular part of A contains the lower triangular part of the matrix A. On exit, if JOBZ = 'V', then if INFO = 0, A contains the orthonormal eigenvectors of the matrix A. If JOBZ = 'N', then on exit the lower triangle (if UPLO='L') or the upper triangle (if UPLO='U') of A, including the diagonal, is destroyed.

offset_a  Int32

 

LDA  Int32

(input) INTEGER The leading dimension of the array A. LDA .GE. max(1,N).

W  Double

(output) DOUBLE PRECISION array, dimension (N) If INFO = 0, the eigenvalues in ascending order.

offset_w  Int32

 

WORK  Double

(workspace/output) DOUBLE PRECISION array, dimension (MAX(1,LWORK)) On exit, if INFO = 0, WORK(1) returns the optimal LWORK.

offset_work  Int32

 

LWORK  Int32

(input) INTEGER The length of the array WORK. LWORK .GE. max(1,3*N-1). For optimal efficiency, LWORK .GE. (NB+2)*N, where NB is the blocksize for DSYTRD returned by ILAENV. If LWORK = -1, then a workspace query is assumed; the routine only calculates the optimal size of the WORK array, returns this value as the first entry of the WORK array, and no error message related to LWORK is issued by XERBLA.

INFO  Int32

(output) INTEGER = 0: successful exit .LT. 0: if INFO = -i, the i-th argument had an illegal value .GT. 0: if INFO = i, the algorithm failed to converge; i off-diagonal elements of an intermediate tridiagonal form did not converge to zero.

Reference