1CLARGV(1)           LAPACK auxiliary routine (version 3.2)           CLARGV(1)
2
3
4

NAME

6       CLARGV  -  generates  a  vector  of  complex  plane rotations with real
7       cosines, determined by elements of the complex vectors x and y
8

SYNOPSIS

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

PURPOSE

19       CLARGV 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          (        c(i)   s(i) ) ( x(i) ) = ( r(i) )
23          ( -conjg(s(i))  c(i) ) ( y(i) ) = (   0  )
24          where c(i)**2 + ABS(s(i))**2 = 1
25       The following conventions are used (these are the same  as  in  CLARTG,
26       but differ from the BLAS1 routine CROTG):
27          If y(i)=0, then c(i)=1 and s(i)=0.
28          If x(i)=0, then c(i)=0 and s(i) is chosen so that r(i) is real.
29

ARGUMENTS

31       N       (input) INTEGER
32               The number of plane rotations to be generated.
33
34       X       (input/output) COMPLEX array, dimension (1+(N-1)*INCX)
35               On  entry, the vector x.  On exit, x(i) is overwritten by r(i),
36               for i = 1,...,n.
37
38       INCX    (input) INTEGER
39               The increment between elements of X. INCX > 0.
40
41       Y       (input/output) COMPLEX array, dimension (1+(N-1)*INCY)
42               On entry, the vector y.  On exit, the sines of the plane  rota‐
43               tions.
44
45       INCY    (input) INTEGER
46               The increment between elements of Y. INCY > 0.
47
48       C       (output) REAL array, dimension (1+(N-1)*INCC)
49               The cosines of the plane rotations.
50
51       INCC    (input) INTEGER
52               The increment between elements of C. INCC > 0.
53

FURTHER DETAILS

55       6-6-96  -  Modified with a new algorithm by W. Kahan and J. Demmel This
56       version has a few statements commented out for thread  safety  (machine
57       parameters are computed on each entry). 10 feb 03, SJH.
58
59
60
61 LAPACK auxiliary routine (versionNo3v.e2m)ber 2008                       CLARGV(1)
Impressum