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

N, ALPHA, X, INCX, TAU )

INTEGER
INCX, N

COMPLEX
ALPHA, TAU

COMPLEX
X( * )
PURPOSE
CLARFG generates a complex elementary reflector H of order n, such
that
( x ) ( 0 )
where alpha and beta are scalars, with beta real, and x is an
(n1)element complex vector. H is represented in the form
H = I  tau * ( 1 ) * ( 1 vaq ) ,
( v )
where tau is a complex scalar and v is a complex (n1)element
vector. Note that H is not hermitian.
If the elements of x are all zero and alpha is real, then tau = 0
and H is taken to be the unit matrix.
Otherwise 1 <= real(tau) <= 2 and abs(tau1) <= 1 .
ARGUMENTS
 N (input) INTEGER

The order of the elementary reflector.
 ALPHA (input/output) COMPLEX

On entry, the value alpha.
On exit, it is overwritten with the value beta.
 X (input/output) COMPLEX 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) COMPLEX

The value tau.
Pages related to clarfg
 clarfg (3)
 clarf (l)  applies a complex elementary reflector H to a complex MbyN matrix C, from either the left or the right
 clarfb (l)  applies a complex block reflector H or its transpose Haq to a complex MbyN matrix C, from either the left or the right
 clarfp (l)  generates a complex elementary reflector H of order n, such that Haq * ( alpha ) = ( beta ), Haq * H = I
 clarft (l)  forms the triangular factor T of a complex block reflector H of order n, which is defined as a product of k elementary reflectors
 clarfx (l)  applies a complex elementary reflector H to a complex m by n matrix C, from either the left or the right
 clar1v (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
 clar2v (l)  applies a vector of complex plane rotations with real cosines from both sides to a sequence of 2by2 complex Hermitian matrices,
 clarcm (l)  performs a very simple matrixmatrix multiplication
 clargv (l)  generates a vector of complex plane rotations with real cosines, determined by elements of the complex vectors x and y