zlarz.f(3) LAPACK zlarz.f(3)NAMEzlarz.f-
SYNOPSIS
Functions/Subroutines
subroutine zlarz (SIDE, M, N, L, V, INCV, TAU, C, LDC, WORK)
ZLARZ applies an elementary reflector (as returned by stzrzf) to a
general matrix.
Function/Subroutine Documentation
subroutine zlarz (characterSIDE, integerM, integerN, integerL, complex*16,
dimension( * )V, integerINCV, complex*16TAU, complex*16, dimension(
ldc, * )C, integerLDC, complex*16, dimension( * )WORK)
ZLARZ applies an elementary reflector (as returned by stzrzf) to a
general matrix.
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:
SIDE
SIDE is CHARACTER*1
= 'L': form H * C
= 'R': form C * H
M
M is INTEGER
The number of rows of the matrix C.
N
N is INTEGER
The number of columns of the matrix C.
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.
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.
INCV
INCV is INTEGER
The increment between elements of v. INCV <> 0.
TAU
TAU is COMPLEX*16
The value tau in the representation of H.
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'.
LDC
LDC is INTEGER
The leading dimension of the array C. LDC >= max(1,M).
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.
Date:
September 2012
Contributors:
A. Petitet, Computer Science Dept., Univ. of Tenn., Knoxville, USA
Further Details:
Definition at line 148 of file zlarz.f.
Author
Generated automatically by Doxygen for LAPACK from the source code.
Version 3.4.2 Sat Nov 16 2013 zlarz.f(3)
