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

#include <sunperf.h>

void zlartg(doublecomplex ∗f, doublecomplex ∗g, double ∗cs, doublecomplex ∗sn, doublecomplex ∗r) ;

PURPOSE

ZLARTG generates a plane rotation so that
   [ -SN  CS  ]     [ G ]     [ 0 ]
 
This is a faster version of the BLAS1 routine ZROTG, except for the following differences:
   F and G are unchanged on return.
   If G=0, then CS=1 and SN=0.
   If F=0 and (G .ne. 0), then CS=0 and SN=1 without doing any
      floating point operations.
 

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.

SunOS 5.0  —  Last change: 10 Dec 1998