dlartg(3F)

NAME
     DLARTG - generate a plane rotation so that   [ CS SN ]

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

         DOUBLE         PRECISION CS, F, G, R, SN

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

     This is a slower, more accurate version of the BLAS1 routine DROTG, 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 DBDSQR when
           there are zeros on the diagonal).

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


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

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

     CS      (output) DOUBLE PRECISION
             The cosine of the rotation.

     SN      (output) DOUBLE PRECISION
             The sine of the rotation.

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