CLARGV(3)      LAPACK routine of NEC Numeric Library Collection      CLARGV(3)



NAME
       CLARGV

SYNOPSIS
       SUBROUTINE CLARGV (N, X, INCX, Y, INCY, C, INCC)



PURPOSE
            CLARGV generates a vector of complex plane rotations with real
            cosines, determined by elements of the complex vectors x and y.
            For i = 1,2,...,n

               (        c(i)   s(i) ) ( x(i) ) = ( r(i) )
               ( -conjg(s(i))  c(i) ) ( y(i) ) = (   0  )

               where c(i)**2 + ABS(s(i))**2 = 1

            The following conventions are used (these are the same as in CLARTG,
            but differ from the BLAS1 routine CROTG):
               If y(i)=0, then c(i)=1 and s(i)=0.
               If x(i)=0, then c(i)=0 and s(i) is chosen so that r(i) is real.




ARGUMENTS
           N         (input)
                     N is INTEGER
                     The number of plane rotations to be generated.

           X         (input/output)
                     X is COMPLEX array, dimension (1+(N-1)*INCX)
                     On entry, the vector x.
                     On exit, x(i) is overwritten by r(i), for i = 1,...,n.

           INCX      (input)
                     INCX is INTEGER
                     The increment between elements of X. INCX > 0.

           Y         (input/output)
                     Y is COMPLEX array, dimension (1+(N-1)*INCY)
                     On entry, the vector y.
                     On exit, the sines of the plane rotations.

           INCY      (input)
                     INCY is INTEGER
                     The increment between elements of Y. INCY > 0.

           C         (output)
                     C is REAL array, dimension (1+(N-1)*INCC)
                     The cosines of the plane rotations.

           INCC      (input)
                     INCC is INTEGER
                     The increment between elements of C. INCC > 0.






FURTHER DETAILS
             6-6-96 - Modified with a new algorithm by W. Kahan and J. Demmel

             This version has a few statements commented out for thread safety
             (machine parameters are computed on each entry). 10 feb 03, SJH.



LAPACK routine                  31 October 2017                      CLARGV(3)