zlarfgp.f - Man Page

SRC/zlarfgp.f

Synopsis

Functions/Subroutines

subroutine zlarfgp (n, alpha, x, incx, tau)
ZLARFGP generates an elementary reflector (Householder matrix) with non-negative beta.

Function/Subroutine Documentation

subroutine zlarfgp (integer n, complex*16 alpha, complex*16, dimension( * ) x, integer incx, complex*16 tau)

ZLARFGP generates an elementary reflector (Householder matrix) with non-negative beta.  

Purpose:

 ZLARFGP 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, beta is real and non-negative, 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.
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 103 of file zlarfgp.f.

Author

Generated automatically by Doxygen for LAPACK from the source code.

Referenced By

The man page zlarfgp(3) is an alias of zlarfgp.f(3).

Tue Nov 28 2023 12:08:42 Version 3.12.0 LAPACK