# zlarfx.f (3) - Linux Man Pages

zlarfx.f -

## SYNOPSIS

### Functions/Subroutines

subroutine zlarfx (SIDE, M, N, V, TAU, C, LDC, WORK)
ZLARFX applies an elementary reflector to a general rectangular matrix, with loop unrolling when the reflector has order ≤ 10.

## Function/Subroutine Documentation

### subroutine zlarfx (characterSIDE, integerM, integerN, complex*16, dimension( * )V, complex*16TAU, complex*16, dimension( ldc, * )C, integerLDC, complex*16, dimension( * )WORK)

ZLARFX applies an elementary reflector to a general rectangular matrix, with loop unrolling when the reflector has order ≤ 10.

Purpose:

``` ZLARFX 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

This version uses inline code if H has order < 11.
```

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.
```

V

```          V is COMPLEX*16 array, dimension (M) if SIDE = 'L'
or (N) if SIDE = 'R'
The vector v in the representation of H.
```

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. LDA >= max(1,M).
```

WORK

```          WORK is COMPLEX*16 array, dimension (N) if SIDE = 'L'
or (M) if SIDE = 'R'
WORK is not referenced if H has order < 11.
```

Author:

Univ. of Tennessee

Univ. of California Berkeley