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, except 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.

F

          F is COMPLEX*16


          The first component of vector to be rotated.

G

          G is COMPLEX*16


          The second component of vector to be rotated.

CS

          CS is DOUBLE PRECISION


          The cosine of the rotation.

SN

          SN is COMPLEX*16


          The sine of the rotation.

R

          R is COMPLEX*16


          The nonzero component of the rotated vector.

Univ. of Tennessee

Univ. of California Berkeley

Univ. of Colorado Denver

NAG Ltd.

December 2016

  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.