SRC/zlarfg.f(3) | Library Functions Manual | SRC/zlarfg.f(3) |
NAME
SRC/zlarfg.f
SYNOPSIS
Functions/Subroutines
subroutine zlarfg (n, alpha, x, incx, tau)
ZLARFG generates an elementary reflector (Householder matrix).
Function/Subroutine Documentation
subroutine zlarfg (integer n, complex*16 alpha, complex*16, dimension( * ) x, integer incx, complex*16 tau)
ZLARFG generates an elementary reflector (Householder matrix).
Purpose:
ZLARFG generates a complex elementary reflector H of order n, such that H**H * ( alpha ) = ( beta ), H**H * H = I. ( x ) ( 0 ) where alpha and beta are scalars, with beta real, and x is an (n-1)-element complex vector. H is represented in the form H = I - tau * ( 1 ) * ( 1 v**H ) , ( v ) where tau is a complex scalar and v is a complex (n-1)-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(tau-1) <= 1 .
Parameters
N
N is INTEGER The order of the elementary reflector.
ALPHA
ALPHA is COMPLEX*16 On entry, the value alpha. On exit, it is overwritten with the value beta.
X
X is COMPLEX*16 array, dimension (1+(N-2)*abs(INCX)) On entry, the vector x. On exit, it is overwritten with the vector v.
INCX
INCX is INTEGER The increment between elements of X. INCX > 0.
TAU
TAU is COMPLEX*16 The value tau.
Author
Univ. of Tennessee
Univ. of California Berkeley
Univ. of Colorado Denver
NAG Ltd.
Definition at line 105 of file zlarfg.f.
Author
Generated automatically by Doxygen for LAPACK from the source code.
Version 3.12.0 | LAPACK |