1SLARTG(1)           LAPACK auxiliary routine (version 3.1)           SLARTG(1)
2
3
4

NAME

6       SLARTG - a plane rotation so that   [ CS SN ]
7

SYNOPSIS

9       SUBROUTINE SLARTG( F, G, CS, SN, R )
10
11           REAL           CS, F, G, R, SN
12

PURPOSE

14       SLARTG generate a plane rotation so that
15          [ -SN  CS  ]     [ G ]     [ 0 ]
16
17       This  is  a  slower,  more accurate version of the BLAS1 routine SROTG,
18       with the following other differences:
19          F and G are unchanged on return.
20          If G=0, then CS=1 and SN=0.
21          If F=0 and (G .ne. 0), then CS=0 and SN=1 without doing any
22             floating point operations (saves work in SBDSQR when
23             there are zeros on the diagonal).
24
25       If F exceeds G in magnitude, CS will be positive.
26
27

ARGUMENTS

29       F       (input) REAL
30               The first component of vector to be rotated.
31
32       G       (input) REAL
33               The second component of vector to be rotated.
34
35       CS      (output) REAL
36               The cosine of the rotation.
37
38       SN      (output) REAL
39               The sine of the rotation.
40
41       R       (output) REAL
42               The nonzero component of the rotated vector.
43
44               This version has a few  statements  commented  out  for  thread
45               safety  (machine parameters are computed on each entry). 10 feb
46               03, SJH.
47
48
49
50 LAPACK auxiliary routine (versionNo3v.e1m)ber 2006                       SLARTG(1)