1ZLARFP(1) LAPACK auxiliary routine (version 3.2) ZLARFP(1)
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6 ZLARFP - generates a complex elementary reflector H of order n, such
7 that H' * ( alpha ) = ( beta ), H' * H = I
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10 SUBROUTINE ZLARFP( N, ALPHA, X, INCX, TAU )
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12 INTEGER INCX, N
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14 COMPLEX*16 ALPHA, TAU
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16 COMPLEX*16 X( * )
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19 ZLARFP generates a complex elementary reflector H of order n, such that
20 ( x ) ( 0 )
21 where alpha and beta are scalars, beta is real and non-negative, and x
22 is an (n-1)-element complex vector. H is represented in the form
23 H = I - tau * ( 1 ) * ( 1 v' ) ,
24 ( v )
25 where tau is a complex scalar and v is a complex (n-1)-element vector.
26 Note that H is not hermitian.
27 If the elements of x are all zero and alpha is real, then tau = 0 and H
28 is taken to be the unit matrix.
29 Otherwise 1 <= real(tau) <= 2 and abs(tau-1) <= 1 .
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32 N (input) INTEGER
33 The order of the elementary reflector.
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35 ALPHA (input/output) COMPLEX*16
36 On entry, the value alpha. On exit, it is overwritten with the
37 value beta.
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39 X (input/output) COMPLEX*16 array, dimension
40 (1+(N-2)*abs(INCX)) On entry, the vector x. On exit, it is
41 overwritten with the vector v.
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43 INCX (input) INTEGER
44 The increment between elements of X. INCX > 0.
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46 TAU (output) COMPLEX*16
47 The value tau.
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51 LAPACK auxiliary routine (versionNo3v.e2m)ber 2008 ZLARFP(1)