slarfg (l)  Linux Man Pages
slarfg: generates a real elementary reflector H of order n, such that H * ( alpha ) = ( beta ), Haq * H = I
Command to display slarfg
manual in Linux: $ man l slarfg
NAME
SLARFG  generates a real elementary reflector H of order n, such that H * ( alpha ) = ( beta ), Haq * H = I
SYNOPSIS
 SUBROUTINE SLARFG(

N, ALPHA, X, INCX, TAU )

INTEGER
INCX, N

REAL
ALPHA, TAU

REAL
X( * )
PURPOSE
SLARFG generates a real elementary reflector H of order n, such
that
( x ) ( 0 )
where alpha and beta are scalars, and x is an (n1)element real
vector. H is represented in the form
H = I  tau * ( 1 ) * ( 1 vaq ) ,
( v )
where tau is a real scalar and v is a real (n1)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+(N2)*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.
Pages related to slarfg
 slarfg (3)
 slarf (l)  applies a real elementary reflector H to a real m by n matrix C, from either the left or the right
 slarfb (l)  applies a real block reflector H or its transpose Haq to a real m by n matrix C, from either the left or the right
 slarfp (l)  generates a real elementary reflector H of order n, such that H * ( alpha ) = ( beta ), Haq * H = I
 slarft (l)  forms the triangular factor T of a real block reflector H of order n, which is defined as a product of k elementary reflectors
 slarfx (l)  applies a real elementary reflector H to a real m by n matrix C, from either the left or the right
 slar1v (l)  computes the (scaled) rth column of the inverse of the sumbmatrix in rows B1 through BN of the tridiagonal matrix L D L^T  sigma I
 slar2v (l)  applies a vector of real plane rotations from both sides to a sequence of 2by2 real symmetric matrices, defined by the elements of the vectors x, y and z
 slargv (l)  generates a vector of real plane rotations, determined by elements of the real vectors x and y
 slarnv (l)  returns a vector of n random real numbers from a uniform or normal distribution