Provided by: liblapack-doc_3.3.1-1_all

**NAME**

LAPACK-3 - generates a plane rotation so that [ CS SN ] [ F ] [ R ] [ __ ]

**SYNOPSIS**

SUBROUTINE ZLARTG( F, G, CS, SN, R ) DOUBLE PRECISION CS COMPLEX*16 F, G, R, SN

**PURPOSE**

ZLARTG generates a plane rotation so that [ -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.

**ARGUMENTS**

F (input) COMPLEX*16 The first component of vector to be rotated. G (input) COMPLEX*16 The second component of vector to be rotated. CS (output) DOUBLE PRECISION The cosine of the rotation. SN (output) COMPLEX*16 The sine of the rotation. R (output) COMPLEX*16 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 (version 3.2) April 2011 ZLARTG(3lapack)