Go to the source code of this file.
|subroutine ||slarfg (N, ALPHA, X, INCX, TAU)|
| ||SLARFG generates an elementary reflector (Householder matrix). |
||real, dimension( * )
SLARFG generates an elementary reflector (Householder matrix).
Download SLARFG + dependencies
SLARFG generates a real elementary reflector H of order n, such
H * ( alpha ) = ( beta ), H**T * H = I.
( x ) ( 0 )
where alpha and beta are scalars, 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
If the elements of x are all zero, then tau = 0 and H is taken to be
the unit matrix.
Otherwise 1 <= tau <= 2.
N is INTEGER
The order of the elementary reflector.
ALPHA is REAL
On entry, the value alpha.
On exit, it is overwritten with the value beta.
X is REAL array, dimension
On entry, the vector x.
On exit, it is overwritten with the vector v.
INCX is INTEGER
The increment between elements of X. INCX > 0.
TAU is REAL
The value tau.
- Univ. of Tennessee
Univ. of California Berkeley
Univ. of Colorado Denver
- September 2012
Definition at line 107 of file slarfg.f.