CentOS 7.0 - man page for dlarf (centos section 3)

```dlarf.f(3)							      LAPACK								dlarf.f(3)

NAME
dlarf.f -

SYNOPSIS
Functions/Subroutines
subroutine dlarf (SIDE, M, N, V, INCV, TAU, C, LDC, WORK)
DLARF applies an elementary reflector to a general rectangular matrix.

Function/Subroutine Documentation
subroutine dlarf (characterSIDE, integerM, integerN, double precision, dimension( * )V, integerINCV, double precisionTAU, double precision,
dimension( ldc, * )C, integerLDC, double precision, dimension( * )WORK)
DLARF applies an elementary reflector to a general rectangular matrix.

Purpose:

DLARF 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.

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
(1 + (M-1)*abs(INCV)) if SIDE = 'L'
or (1 + (N-1)*abs(INCV)) if SIDE = 'R'
The vector v in the representation of H. V is not used if
TAU = 0.

INCV

INCV is INTEGER
The increment between elements of v. INCV <> 0.

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. LDC >= max(1,M).

WORK

WORK is DOUBLE PRECISION array, dimension
(N) if SIDE = 'L'
or (M) if SIDE = 'R'

Author:
Univ. of Tennessee

Univ. of California Berkeley