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



NAME
       SLARTG - a plane rotation so that   [ CS SN ]

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

           REAL           CS, F, G, R, SN

PURPOSE
       SLARTG generate a plane rotation so that
          [ -SN  CS  ]     [ G ]     [ 0 ]

       This is a slower, more accurate version of the BLAS1 routine SROTG,
       with the following other 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 (saves work in SBDSQR when
             there are zeros on the diagonal).

       If F exceeds G in magnitude, CS will be positive.


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

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

       CS      (output) REAL
               The cosine of the rotation.

       SN      (output) REAL
               The sine of the rotation.

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

               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                      SLARTG(3f)
