zlarz()

subroutine zlarz	(	character	side,
		integer	m,
		integer	n,
		integer	l,
		complex*16, dimension( * )	v,
		integer	incv,
		complex*16	tau,
		complex*16, dimension( ldc, * )	c,
		integer	ldc,
		complex*16, dimension( * )	work )

ZLARZ applies an elementary reflector (as returned by stzrzf) to a general matrix.

Download ZLARZ + dependencies [TGZ] [ZIP] [TXT]

Purpose:

!>
!> ZLARZ applies a complex elementary reflector H to a complex
!> M-by-N matrix C, from either the left or the right. H is represented
!> in the form
!>
!>       H = I - tau * v * v**H
!>
!> where tau is a complex scalar and v is a complex vector.
!>
!> If tau = 0, then H is taken to be the unit matrix.
!>
!> To apply H**H (the conjugate transpose of H), supply conjg(tau) instead
!> tau.
!>
!> H is a product of k elementary reflectors as returned by ZTZRZF.
!> 

Parameters

[in]	SIDE	!> SIDE is CHARACTER*1 !> = 'L': form H * C !> = 'R': form C * H !>
[in]	M	!> M is INTEGER !> The number of rows of the matrix C. !>
[in]	N	!> N is INTEGER !> The number of columns of the matrix C. !>
[in]	L	!> L is INTEGER !> The number of entries of the vector V containing !> the meaningful part of the Householder vectors. !> If SIDE = 'L', M >= L >= 0, if SIDE = 'R', N >= L >= 0. !>
[in]	V	!> V is COMPLEX*16 array, dimension (1+(L-1)*abs(INCV)) !> The vector v in the representation of H as returned by !> ZTZRZF. V is not used if TAU = 0. !>
[in]	INCV	!> INCV is INTEGER !> The increment between elements of v. INCV <> 0. !>
[in]	TAU	!> TAU is COMPLEX*16 !> The value tau in the representation of H. !>
[in,out]	C	!> C is COMPLEX*16 array, dimension (LDC,N) !> On entry, the M-by-N matrix C. !> On exit, C is overwritten by the matrix H * C if SIDE = 'L', !> or C * H if SIDE = 'R'. !>
[in]	LDC	!> LDC is INTEGER !> The leading dimension of the array C. LDC >= max(1,M). !>
[out]	WORK	!> WORK is COMPLEX*16 array, dimension !> (N) if SIDE = 'L' !> or (M) if SIDE = 'R' !>

Author

Univ. of Tennessee

Univ. of California Berkeley

Univ. of Colorado Denver

NAG Ltd.

Contributors:

A. Petitet, Computer Science Dept., Univ. of Tenn., Knoxville, USA

Further Details:

!>