slarfp (l) - Linux Man Pages

slarfp: generates a real elementary reflector H of order n, such that H * ( alpha ) = ( beta ), Haq * H = I

NAME

SLARFP - generates a real elementary reflector H of order n, such that H * ( alpha ) = ( beta ), Haq * H = I

SYNOPSIS

SUBROUTINE SLARFP(
N, ALPHA, X, INCX, TAU )

    
INTEGER INCX, N

    
REAL ALPHA, TAU

    
REAL X( * )

PURPOSE

SLARFP generates a real elementary reflector H of order n, such that
             )
where alpha and beta are scalars, beta is non-negative, and x is an (n-1)-element real vector. H is represented in the form
I - tau 1 vaq ,

              )
where tau is a real scalar and v is a real (n-1)-element
vector.
If the elements of x are all zero, then tau = 0 and H is taken to be the unit matrix.
Otherwise 1 <= tau <= 2.

ARGUMENTS

N (input) INTEGER
The order of the elementary reflector.
ALPHA (input/output) REAL
On entry, the value alpha. On exit, it is overwritten with the value beta.
X (input/output) REAL array, dimension
(1+(N-2)*abs(INCX)) On entry, the vector x. On exit, it is overwritten with the vector v.
INCX (input) INTEGER
The increment between elements of X. INCX > 0.
TAU (output) REAL
The value tau.