CXML
        	    
LAPACK version 3.0
zlargv(3)

PURPOSE
  ZLARGV - generate a vector of complex plane rotations with real cosines,
  determined by elements of the complex vectors x and y

SYNTAX
  SUBROUTINE ZLARGV( N, X, INCX, Y, INCY, C, INCC )

      INTEGER	     INCC, INCX, INCY, N

      DOUBLE	     PRECISION C( * )

      COMPLEX*16     X( * ), Y( * )

DESCRIPTION
  ZLARGV 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 ZLARTG, but
  differ from the BLAS1 routine ZROTG):
     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) INTEGER
	  The number of plane rotations to be generated.

  X	  (input/output) COMPLEX*16 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) INTEGER
	  The increment between elements of X. INCX > 0.

  Y	  (input/output) COMPLEX*16 array, dimension (1+(N-1)*INCY)
	  On entry, the vector y.  On exit, the sines of the plane rotations.

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

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

  INCC	  (input) 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