clarfgp.f man page

clarfgp.f —

Synopsis

Functions/Subroutines

subroutine clarfgp (N, ALPHA, X, INCX, TAU)
CLARFGP generates an elementary reflector (Householder matrix) with non-negatibe beta.

Function/Subroutine Documentation

subroutine clarfgp (integerN, complexALPHA, complex, dimension( * )X, integerINCX, complexTAU)

CLARFGP generates an elementary reflector (Householder matrix) with non-negatibe beta.

Purpose:

CLARFGP 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
On entry, the value alpha.
On exit, it is overwritten with the value beta.

X

X is COMPLEX 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
The value tau.

Author:

Univ. of Tennessee

Univ. of California Berkeley

Univ. of Colorado Denver

NAG Ltd.

Date:

September 2012

Definition at line 105 of file clarfgp.f.

Author

Generated automatically by Doxygen for LAPACK from the source code.

Referenced By

clarfgp(3) is an alias of clarfgp.f(3).

Sat Nov 16 2013 Version 3.4.2 LAPACK