GNU/Linux man pages
Livre :
Expressions régulières,
Syntaxe et mise en oeuvre :
GNU/Linux |
CentOS 4.8 |
i386 |
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clarfg(l) |
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CLARFG - generate a complex elementary reflector H of order n, such that H’ * ( alpha ) = ( beta ), H’ * H = I
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SUBROUTINE CLARFG( |
N, ALPHA, X, INCX, TAU ) |
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INTEGER |
INCX, N |
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COMPLEX |
ALPHA, TAU |
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COMPLEX |
X( * ) |
CLARFG generates a complex elementary reflector H of order n, such that H’ * ( alpha ) = ( beta ), 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’ ) ,
( 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 .
N (input) INTEGER
The order of the elementary reflector.
ALPHA (input/output) COMPLEX
On entry, the value alpha. On exit, it is overwritten with the value beta.
X (input/output) COMPLEX array, dimension
(1+(N-2)*abs(INCX)) On entry, the vector x. On exit, it is overwritten with the vector v.
INCX (input) INTEGER
The increment between elements of X. INCX > 0.
TAU (output) COMPLEX
The value tau.
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clarfg(l) | |