zlartg(3)

NAME

ZLARTG - generate a plane rotation so that [ CS SN ] [ F

] [ R ] [ __ ]

SYNOPSIS

SUBROUTINE ZLARTG( F, G, CS, SN, R )
    DOUBLE         PRECISION CS
    COMPLEX*16     F, G, R, SN

PURPOSE

ZLARTG generates a plane rotation so that [ CS SN ] [ F ]

[ R ] [ __ ] . [ ] = [ ] where CS**2 + |SN|**2 = 1. [ -SN CS

] [ G ] [ 0 ]

This is a faster version of the BLAS1 routine ZROTG, ex

cept for the following differences:

F and G are unchanged on return.
If G=0, then CS=1 and SN=0.
If F=0, then CS=0 and SN is chosen so that R is real.

ARGUMENTS

F (input) COMPLEX*16

The first component of vector to be rotated.

G (input) COMPLEX*16

The second component of vector to be rotated.

CS (output) DOUBLE PRECISION

The cosine of the rotation.

SN (output) COMPLEX*16

The sine of the rotation.

R (output) COMPLEX*16

The nonzero component of the rotated vector.

FURTHER DETAILS

3-5-96 - Modified with a new algorithm by W. Kahan and J.

Demmel

LAPACK version 3.0 15 June 2000

ZLARTG(3)