ZLARGV(1) LAPACK auxiliary routine (version 3.2) ZLARGV(1)NAME
ZLARGV - generates a vector of complex plane rotations with real
cosines, determined by elements of the complex vectors x and y
SYNOPSIS
SUBROUTINE ZLARGV( N, X, INCX, Y, INCY, C, INCC )
INTEGER INCC, INCX, INCY, N
DOUBLE PRECISION C( * )
COMPLEX*16 X( * ), Y( * )
PURPOSE
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 rota‐
tions.
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 This
version has a few statements commented out for thread safety (machine
parameters are computed on each entry). 10 feb 03, SJH.
LAPACK auxiliary routine (versioNovember 2008 ZLARGV(1)
