DLAQR5Run Method

public void Run(
	bool WANTT,
	bool WANTZ,
	int KACC22,
	int N,
	int KTOP,
	int KBOT,
	int NSHFTS,
	ref double[] SR,
	int offset_sr,
	ref double[] SI,
	int offset_si,
	ref double[] H,
	int offset_h,
	int LDH,
	int ILOZ,
	int IHIZ,
	ref double[] Z,
	int offset_z,
	int LDZ,
	ref double[] V,
	int offset_v,
	int LDV,
	ref double[] U,
	int offset_u,
	int LDU,
	int NV,
	ref double[] WV,
	int offset_wv,
	int LDWV,
	int NH,
	ref double[] WH,
	int offset_wh,
	int LDWH
)

Public Sub Run ( 
	WANTT As Boolean,
	WANTZ As Boolean,
	KACC22 As Integer,
	N As Integer,
	KTOP As Integer,
	KBOT As Integer,
	NSHFTS As Integer,
	ByRef SR As Double(),
	offset_sr As Integer,
	ByRef SI As Double(),
	offset_si As Integer,
	ByRef H As Double(),
	offset_h As Integer,
	LDH As Integer,
	ILOZ As Integer,
	IHIZ As Integer,
	ByRef Z As Double(),
	offset_z As Integer,
	LDZ As Integer,
	ByRef V As Double(),
	offset_v As Integer,
	LDV As Integer,
	ByRef U As Double(),
	offset_u As Integer,
	LDU As Integer,
	NV As Integer,
	ByRef WV As Double(),
	offset_wv As Integer,
	LDWV As Integer,
	NH As Integer,
	ByRef WH As Double(),
	offset_wh As Integer,
	LDWH As Integer
)

Parameters

WANTT  Boolean

(input) logical scalar WANTT = .true. if the quasi-triangular Schur factor is being computed. WANTT is set to .false. otherwise.

WANTZ  Boolean

(input) logical scalar WANTZ = .true. if the orthogonal Schur factor is being computed. WANTZ is set to .false. otherwise.

KACC22  Int32

(input) integer with value 0, 1, or 2. Specifies the computation mode of far-from-diagonal orthogonal updates. = 0: DLAQR5 does not accumulate reflections and does not use matrix-matrix multiply to update far-from-diagonal matrix entries. = 1: DLAQR5 accumulates reflections and uses matrix-matrix multiply to update the far-from-diagonal matrix entries. = 2: DLAQR5 accumulates reflections, uses matrix-matrix multiply to update the far-from-diagonal matrix entries, and takes advantage of 2-by-2 block structure during matrix multiplies.

N  Int32

(input) integer scalar N is the order of the Hessenberg matrix H upon which this subroutine operates.

KTOP  Int32

(input) integer scalar

KBOT  Int32

(input) integer scalar These are the first and last rows and columns of an isolated diagonal block upon which the QR sweep is to be applied. It is assumed without a check that either KTOP = 1 or H(KTOP,KTOP-1) = 0 and either KBOT = N or H(KBOT+1,KBOT) = 0.

NSHFTS  Int32

(input) integer scalar NSHFTS gives the number of simultaneous shifts. NSHFTS must be positive and even.

SR  Double

(input) DOUBLE PRECISION array of size (NSHFTS)

offset_sr  Int32

 

SI  Double

(input) DOUBLE PRECISION array of size (NSHFTS) SR contains the real parts and SI contains the imaginary parts of the NSHFTS shifts of origin that define the multi-shift QR sweep.

offset_si  Int32

 

H  Double

(input/output) DOUBLE PRECISION array of size (LDH,N) On input H contains a Hessenberg matrix. On output a multi-shift QR sweep with shifts SR(J)+i*SI(J) is applied to the isolated diagonal block in rows and columns KTOP through KBOT.

offset_h  Int32

 

LDH  Int32

(input) integer scalar LDH is the leading dimension of H just as declared in the calling procedure. LDH.GE.MAX(1,N).

ILOZ  Int32

(input) INTEGER

IHIZ  Int32

(input) INTEGER Specify the rows of Z to which transformations must be applied if WANTZ is .TRUE.. 1 .LE. ILOZ .LE. IHIZ .LE. N

Z  Double

(input/output) DOUBLE PRECISION array of size (LDZ,IHI) If WANTZ = .TRUE., then the QR Sweep orthogonal similarity transformation is accumulated into Z(ILOZ:IHIZ,ILO:IHI) from the right. If WANTZ = .FALSE., then Z is unreferenced.

offset_z  Int32

 

LDZ  Int32

(input) integer scalar LDA is the leading dimension of Z just as declared in the calling procedure. LDZ.GE.N.

V  Double

(workspace) DOUBLE PRECISION array of size (LDV,NSHFTS/2)

offset_v  Int32

 

LDV  Int32

(input) integer scalar LDV is the leading dimension of V as declared in the calling procedure. LDV.GE.3.

U  Double

(workspace) DOUBLE PRECISION array of size (LDU,3*NSHFTS-3)

offset_u  Int32

 

LDU  Int32

(input) integer scalar LDU is the leading dimension of U just as declared in the in the calling subroutine. LDU.GE.3*NSHFTS-3.

NV  Int32

(input) integer scalar NV is the number of rows in WV agailable for workspace. NV.GE.1.

WV  Double

(workspace) DOUBLE PRECISION array of size (LDWV,3*NSHFTS-3)

offset_wv  Int32

 

LDWV  Int32

(input) integer scalar LDWV is the leading dimension of WV as declared in the in the calling subroutine. LDWV.GE.NV.

NH  Int32

(input) integer scalar NH is the number of columns in array WH available for workspace. NH.GE.1.

WH  Double

(workspace) DOUBLE PRECISION array of size (LDWH,NH)

offset_wh  Int32

 

LDWH  Int32

(input) integer scalar Leading dimension of WH just as declared in the calling procedure. LDWH.GE.3*NSHFTS-3.

Reference