1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
|
/* crotg.f -- translated by f2c (version 20061008).
You must link the resulting object file with libf2c:
on Microsoft Windows system, link with libf2c.lib;
on Linux or Unix systems, link with .../path/to/libf2c.a -lm
or, if you install libf2c.a in a standard place, with -lf2c -lm
-- in that order, at the end of the command line, as in
cc *.o -lf2c -lm
Source for libf2c is in /netlib/f2c/libf2c.zip, e.g.,
http://www.netlib.org/f2c/libf2c.zip
*/
#include "f2c.h"
#include "blaswrap.h"
/* Subroutine */ int crotg_(complex *ca, complex *cb, real *c__, complex *s)
{
/* System generated locals */
real r__1, r__2;
complex q__1, q__2, q__3;
/* Builtin functions */
double c_abs(complex *), sqrt(doublereal);
void r_cnjg(complex *, complex *);
/* Local variables */
real norm;
complex alpha;
real scale;
/* .. Scalar Arguments .. */
/* .. */
/* Purpose */
/* ======= */
/* CROTG determines a complex Givens rotation. */
/* .. Local Scalars .. */
/* .. */
/* .. Intrinsic Functions .. */
/* .. */
if (c_abs(ca) != 0.f) {
goto L10;
}
*c__ = 0.f;
s->r = 1.f, s->i = 0.f;
ca->r = cb->r, ca->i = cb->i;
goto L20;
L10:
scale = c_abs(ca) + c_abs(cb);
q__1.r = ca->r / scale, q__1.i = ca->i / scale;
/* Computing 2nd power */
r__1 = c_abs(&q__1);
q__2.r = cb->r / scale, q__2.i = cb->i / scale;
/* Computing 2nd power */
r__2 = c_abs(&q__2);
norm = scale * sqrt(r__1 * r__1 + r__2 * r__2);
r__1 = c_abs(ca);
q__1.r = ca->r / r__1, q__1.i = ca->i / r__1;
alpha.r = q__1.r, alpha.i = q__1.i;
*c__ = c_abs(ca) / norm;
r_cnjg(&q__3, cb);
q__2.r = alpha.r * q__3.r - alpha.i * q__3.i, q__2.i = alpha.r * q__3.i +
alpha.i * q__3.r;
q__1.r = q__2.r / norm, q__1.i = q__2.i / norm;
s->r = q__1.r, s->i = q__1.i;
q__1.r = norm * alpha.r, q__1.i = norm * alpha.i;
ca->r = q__1.r, ca->i = q__1.i;
L20:
return 0;
} /* crotg_ */
|
