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# CentOS 7.0 - man page for dlarfx (centos section 3)

```dlarfx.f(3)						LAPACK						  dlarfx.f(3)

NAME
dlarfx.f -

SYNOPSIS
Functions/Subroutines
subroutine dlarfx (SIDE, M, N, V, TAU, C, LDC, WORK)
DLARFX applies an elementary reflector to a general rectangular matrix, with loop unrolling when the
reflector has order <= 10.

Function/Subroutine Documentation
subroutine dlarfx (characterSIDE, integerM, integerN, double precision, dimension( * )V, double precisionTAU,
double precision, dimension( ldc, * )C, integerLDC, double precision, dimension( * )WORK)
DLARFX applies an elementary reflector to a general rectangular matrix, with loop unrolling when the reflector
has order <= 10.

Purpose:

DLARFX applies a real elementary reflector H to a real m by n
matrix C, from either the left or the right. H is represented in the
form

H = I - tau * v * v**T

where tau is a real scalar and v is a real 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 DOUBLE PRECISION array, dimension (M) if SIDE = 'L'
or (N) if SIDE = 'R'
The vector v in the representation of H.

TAU

TAU is DOUBLE PRECISION
The value tau in the representation of H.

C

C is DOUBLE PRECISION 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 >= (1,M).

WORK

WORK is DOUBLE PRECISION 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

NAG Ltd.

Date:
September 2012

Definition at line 121 of file dlarfx.f.

Author
Generated automatically by Doxygen for LAPACK from the source code.

Version 3.4.2					   Tue Sep 25 2012					  dlarfx.f(3)```

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