mirror of
https://github.com/opencv/opencv.git
synced 2024-11-25 19:50:38 +08:00
74 lines
1.7 KiB
C
74 lines
1.7 KiB
C
/* dlapy2.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 "clapack.h"
|
|
|
|
|
|
doublereal dlapy2_(doublereal *x, doublereal *y)
|
|
{
|
|
/* System generated locals */
|
|
doublereal ret_val, d__1;
|
|
|
|
/* Builtin functions */
|
|
double sqrt(doublereal);
|
|
|
|
/* Local variables */
|
|
doublereal w, z__, xabs, yabs;
|
|
|
|
|
|
/* -- LAPACK auxiliary routine (version 3.2) -- */
|
|
/* Univ. of Tennessee, Univ. of California Berkeley and NAG Ltd.. */
|
|
/* November 2006 */
|
|
|
|
/* .. Scalar Arguments .. */
|
|
/* .. */
|
|
|
|
/* Purpose */
|
|
/* ======= */
|
|
|
|
/* DLAPY2 returns sqrt(x**2+y**2), taking care not to cause unnecessary */
|
|
/* overflow. */
|
|
|
|
/* Arguments */
|
|
/* ========= */
|
|
|
|
/* X (input) DOUBLE PRECISION */
|
|
/* Y (input) DOUBLE PRECISION */
|
|
/* X and Y specify the values x and y. */
|
|
|
|
/* ===================================================================== */
|
|
|
|
/* .. Parameters .. */
|
|
/* .. */
|
|
/* .. Local Scalars .. */
|
|
/* .. */
|
|
/* .. Intrinsic Functions .. */
|
|
/* .. */
|
|
/* .. Executable Statements .. */
|
|
|
|
xabs = abs(*x);
|
|
yabs = abs(*y);
|
|
w = max(xabs,yabs);
|
|
z__ = min(xabs,yabs);
|
|
if (z__ == 0.) {
|
|
ret_val = w;
|
|
} else {
|
|
/* Computing 2nd power */
|
|
d__1 = z__ / w;
|
|
ret_val = w * sqrt(d__1 * d__1 + 1.);
|
|
}
|
|
return ret_val;
|
|
|
|
/* End of DLAPY2 */
|
|
|
|
} /* dlapy2_ */
|