.TH ZLARTG 1 "November 2006" " LAPACK auxiliary routine (version 3.1) " " LAPACK auxiliary routine (version 3.1) "
.SH NAME
ZLARTG - a plane rotation so that [ CS SN ] [ F ] [ R ] [ __ ]
.SH SYNOPSIS
.TP 19
SUBROUTINE ZLARTG(
F, G, CS, SN, R )
.TP 19
.ti +4
DOUBLE
PRECISION CS
.TP 19
.ti +4
COMPLEX*16
F, G, R, SN
.SH PURPOSE
ZLARTG generates a plane rotation so that
[ -SN CS ] [ G ] [ 0 ]
.br
This is a faster version of the BLAS1 routine ZROTG, except for
the following differences:
.br
F and G are unchanged on return.
.br
If G=0, then CS=1 and SN=0.
.br
If F=0, then CS=0 and SN is chosen so that R is real.
.br
.SH ARGUMENTS
.TP 8
F (input) COMPLEX*16
The first component of vector to be rotated.
.TP 8
G (input) COMPLEX*16
The second component of vector to be rotated.
.TP 8
CS (output) DOUBLE PRECISION
The cosine of the rotation.
.TP 8
SN (output) COMPLEX*16
The sine of the rotation.
.TP 8
R (output) COMPLEX*16
The nonzero component of the rotated vector.
.SH FURTHER DETAILS
3-5-96 - 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.