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zlarz.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
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

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