CLARTG(3f)          LAPACK auxiliary routine (version 3.1)          CLARTG(3f)



NAME
       CLARTG - a plane rotation so that   [ CS SN ] [ F ] [ R ]  [ __ ]

SYNOPSIS
       SUBROUTINE CLARTG( F, G, CS, SN, R )

           REAL           CS

           COMPLEX        F, G, R, SN

PURPOSE
       CLARTG generates a plane rotation so that
          [ -SN  CS  ]     [ G ]     [ 0 ]

       This is a faster version of the BLAS1 routine CROTG, 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.


ARGUMENTS
       F       (input) COMPLEX
               The first component of vector to be rotated.

       G       (input) COMPLEX
               The second component of vector to be rotated.

       CS      (output) REAL
               The cosine of the rotation.

       SN      (output) COMPLEX
               The sine of the rotation.

       R       (output) COMPLEX
               The nonzero component of the rotated vector.

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.




 LAPACK auxiliary routine (versioNovember 2006                      CLARTG(3f)
