man dlarfx (Fonctions bibliothèques) - applie a real elementary reflector H to a real m by n matrix C, from either the left or the right

NAME

DLARFX - applie a real elementary reflector H to a real m by n matrix C, from either the left or the right

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'

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) DOUBLE PRECISION array, dimension (M) if SIDE = 'L': or (N) if SIDE = 'R' The vector v in the representation of H.
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. LDA >= (1,M).
WORK (workspace) DOUBLE PRECISION array, dimension: (N) if SIDE = 'L' or (M) if SIDE = 'R' WORK is not referenced if H has order < 11.