dlarfgp.f - Man Page
SRC/dlarfgp.f
Synopsis
Functions/Subroutines
subroutine dlarfgp (n, alpha, x, incx, tau)
DLARFGP generates an elementary reflector (Householder matrix) with non-negative beta.
Function/Subroutine Documentation
subroutine dlarfgp (integer n, double precision alpha, double precision, dimension( * ) x, integer incx, double precision tau)
DLARFGP generates an elementary reflector (Householder matrix) with non-negative beta.
Purpose:
DLARFGP generates a real elementary reflector H of order n, such that H * ( alpha ) = ( beta ), H**T * H = I. ( x ) ( 0 ) where alpha and beta are scalars, beta is non-negative, and x is an (n-1)-element real vector. H is represented in the form H = I - tau * ( 1 ) * ( 1 v**T ) , ( v ) where tau is a real scalar and v is a real (n-1)-element vector. If the elements of x are all zero, 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 DOUBLE PRECISION On entry, the value alpha. On exit, it is overwritten with the value beta.
X
X is DOUBLE PRECISION 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 DOUBLE PRECISION The value tau.
- Author
Univ. of Tennessee
Univ. of California Berkeley
Univ. of Colorado Denver
NAG Ltd.
Definition at line 103 of file dlarfgp.f.
Author
Generated automatically by Doxygen for LAPACK from the source code.
Referenced By
The man page dlarfgp(3) is an alias of dlarfgp.f(3).
Tue Nov 28 2023 12:08:42 Version 3.12.0 LAPACK