Provided by: liblapack-doc_3.3.1-1_all NAME

LAPACK-3  -  applies  a real elementary reflector H to a real m by n matrix C, from either
the left or the right

SYNOPSIS

SUBROUTINE DLARF( SIDE, M, N, V, INCV, TAU, C, LDC, WORK )

IMPLICIT      NONE

CHARACTER     SIDE

INTEGER       INCV, LDC, M, N

DOUBLE        PRECISION TAU

DOUBLE        PRECISION C( LDC, * ), V( * ), WORK( * )

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.

ARGUMENTS

SIDE    (input) CHARACTER*1
= 'L': form  H * C
= 'R': form  C * H

M       (input) INTEGER
The number of rows of the matrix C.

N       (input) INTEGER
The number of columns of the matrix C.

V       (input) 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    (input) INTEGER
The increment between elements of v. INCV <> 0.

TAU     (input) DOUBLE PRECISION
The value tau in the representation of H.

C       (input/output) 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     (input) INTEGER
The leading dimension of the array C. LDC >= max(1,M).

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

LAPACK auxiliary routine (version 3.3.1)   April 2011                             DLARF(3lapack)