redhat man page for zlarz

ZLARZ(l)								 )								  ZLARZ(l)

NAME
       ZLARZ - applie a complex elementary reflector H to a complex M-by-N matrix C, from either the left or the right

SYNOPSIS
       SUBROUTINE ZLARZ( SIDE, M, N, L, V, INCV, TAU, C, LDC, WORK )

	   CHARACTER	 SIDE

	   INTEGER	 INCV, L, LDC, M, N

	   COMPLEX*16	 TAU

	   COMPLEX*16	 C( LDC, * ), V( * ), WORK( * )

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'

       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' (the conjugate transpose of H), supply conjg(tau) instead tau.

       H is a product of k elementary reflectors as returned by ZTZRZF.

ARGUMENTS
       SIDE    (input) CHARACTER*1
	       = 'L': form  H * C
	       = 'R': form  C * H

       M       (input) INTEGER
	       The number of rows of the matrix C.

       N       (input) INTEGER
	       The number of columns of the matrix C.

       L       (input) 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.

       V       (input) 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.

       INCV    (input) INTEGER
	       The increment between elements of v. INCV <> 0.

       TAU     (input) COMPLEX*16
	       The value tau in the representation of H.

       C       (input/output) 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'.

       LDC     (input) INTEGER
	       The leading dimension of the array C. LDC >= max(1,M).

       WORK    (workspace) COMPLEX*16 array, dimension
	       (N) if SIDE = 'L' or (M) if SIDE = 'R'

FURTHER DETAILS
       Based on contributions by
	 A. Petitet, Computer Science Dept., Univ. of Tenn., Knoxville, USA

LAPACK version 3.0						   15 June 2000 							  ZLARZ(l)