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
73
74
75
76
77
78
79
80
81
|
/* ../../../dependencies/lapack/src/slapy3.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"
doublereal slapy3_(real *x, real *y, real *z__)
{
/* System generated locals */
real ret_val, r__1, r__2, r__3;
/* Builtin functions */
double sqrt(doublereal);
/* Local variables */
static real w, xabs, yabs, zabs;
/* -- LAPACK auxiliary routine (version 3.0) -- */
/* Univ. of Tennessee, Univ. of California Berkeley, NAG Ltd., */
/* Courant Institute, Argonne National Lab, and Rice University */
/* October 31, 1992 */
/* .. Scalar Arguments .. */
/* .. */
/* Purpose */
/* ======= */
/* SLAPY3 returns sqrt(x**2+y**2+z**2), taking care not to cause */
/* unnecessary overflow. */
/* Arguments */
/* ========= */
/* X (input) REAL */
/* Y (input) REAL */
/* Z (input) REAL */
/* X, Y and Z specify the values x, y and z. */
/* ===================================================================== */
/* .. Parameters .. */
/* .. */
/* .. Local Scalars .. */
/* .. */
/* .. Intrinsic Functions .. */
/* .. */
/* .. Executable Statements .. */
xabs = dabs(*x);
yabs = dabs(*y);
zabs = dabs(*z__);
/* Computing MAX */
r__1 = max(xabs,yabs);
w = dmax(r__1,zabs);
if (w == 0.f) {
ret_val = 0.f;
} else {
/* Computing 2nd power */
r__1 = xabs / w;
/* Computing 2nd power */
r__2 = yabs / w;
/* Computing 2nd power */
r__3 = zabs / w;
ret_val = w * sqrt(r__1 * r__1 + r__2 * r__2 + r__3 * r__3);
}
return ret_val;
/* End of SLAPY3 */
} /* slapy3_ */
|
