redhat man page for dlartg

DLARTG(l)								 )								 DLARTG(l)

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 [ CS SN ] . [ F ] = [ R ] where CS**2 + SN**2 = 1.    [ -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.

LAPACK version 3.0						   15 June 2000 							 DLARTG(l)