SLARFX(l) ) SLARFX(l)
SLARFX - applie a real elementary reflector H to a real m by n matrix C, from either the
left or the right
SUBROUTINE SLARFX( SIDE, M, N, V, TAU, C, LDC, WORK )
INTEGER LDC, M, N
REAL C( LDC, * ), V( * ), WORK( * )
SLARFX 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'
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.
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) REAL array, dimension (M) if SIDE = 'L'
or (N) if SIDE = 'R' The vector v in the representation of H.
TAU (input) REAL
The value tau in the representation of H.
C (input/output) REAL 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. LDA >= (1,M).
WORK (workspace) REAL array, dimension
(N) if SIDE = 'L' or (M) if SIDE = 'R' WORK is not referenced if H has order < 11.
LAPACK version 3.0 15 June 2000 SLARFX(l)