1ZLARGV(1)           LAPACK auxiliary routine (version 3.1)           ZLARGV(1)
2
3
4

NAME

6       ZLARGV  - a vector of complex plane rotations with real cosines, deter‐
7       mined by elements of the complex vectors x and y
8

SYNOPSIS

10       SUBROUTINE ZLARGV( N, X, INCX, Y, INCY, C, INCC )
11
12           INTEGER        INCC, INCX, INCY, N
13
14           DOUBLE         PRECISION C( * )
15
16           COMPLEX*16     X( * ), Y( * )
17

PURPOSE

19       ZLARGV generates a vector of complex plane rotations with real cosines,
20       determined  by  elements  of  the  complex  vectors  x  and y.  For i =
21       1,2,...,n
22
23          (        c(i)   s(i) ) ( x(i) ) = ( r(i) )
24          ( -conjg(s(i))  c(i) ) ( y(i) ) = (   0  )
25
26          where c(i)**2 + ABS(s(i))**2 = 1
27
28       The following conventions are used (these are the same  as  in  ZLARTG,
29       but differ from the BLAS1 routine ZROTG):
30          If y(i)=0, then c(i)=1 and s(i)=0.
31          If x(i)=0, then c(i)=0 and s(i) is chosen so that r(i) is real.
32
33

ARGUMENTS

35       N       (input) INTEGER
36               The number of plane rotations to be generated.
37
38       X       (input/output) COMPLEX*16 array, dimension (1+(N-1)*INCX)
39               On  entry, the vector x.  On exit, x(i) is overwritten by r(i),
40               for i = 1,...,n.
41
42       INCX    (input) INTEGER
43               The increment between elements of X. INCX > 0.
44
45       Y       (input/output) COMPLEX*16 array, dimension (1+(N-1)*INCY)
46               On entry, the vector y.  On exit, the sines of the plane  rota‐
47               tions.
48
49       INCY    (input) INTEGER
50               The increment between elements of Y. INCY > 0.
51
52       C       (output) DOUBLE PRECISION array, dimension (1+(N-1)*INCC)
53               The cosines of the plane rotations.
54
55       INCC    (input) INTEGER
56               The increment between elements of C. INCC > 0.
57

FURTHER DETAILS

59       6-6-96 - Modified with a new algorithm by W. Kahan and J. Demmel
60
61       This  version  has  a  few  statements  commented out for thread safety
62       (machine parameters are computed on each entry). 10 feb 03, SJH.
63
64
65
66
67 LAPACK auxiliary routine (versionNo3v.e1m)ber 2006                       ZLARGV(1)
Impressum