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/* eispack/pythag.f -- translated by f2c (version 20050501).
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
*/
#ifdef __cplusplus
extern "C" {
#endif
#include "v3p_netlib.h"
/*< double precision function pythag(a,b) >*/
doublereal pythag_(doublereal *a, doublereal *b)
{
/* System generated locals */
doublereal ret_val, d__1, d__2, d__3;
/* Local variables */
doublereal p, r__, s, t, u;
/*< double precision a,b >*/
/* finds dsqrt(a**2+b**2) without overflow or destructive underflow */
/*< double precision p,r,s,t,u >*/
/*< p = dmax1(dabs(a),dabs(b)) >*/
/* Computing MAX */
d__1 = abs(*a), d__2 = abs(*b);
p = max(d__1,d__2);
/*< if (p .eq. 0.0d0) go to 20 >*/
if (p == 0.) {
goto L20;
}
/*< r = (dmin1(dabs(a),dabs(b))/p)**2 >*/
/* Computing MIN */
d__2 = abs(*a), d__3 = abs(*b);
/* Computing 2nd power */
d__1 = min(d__2,d__3) / p;
r__ = d__1 * d__1;
/*< 10 continue >*/
L10:
/*< t = 4.0d0 + r >*/
t = r__ + 4.;
/*< if (t .eq. 4.0d0) go to 20 >*/
if (t == 4.) {
goto L20;
}
/*< s = r/t >*/
s = r__ / t;
/*< u = 1.0d0 + 2.0d0*s >*/
u = s * 2. + 1.;
/*< p = u*p >*/
p = u * p;
/*< r = (s/u)**2 * r >*/
/* Computing 2nd power */
d__1 = s / u;
r__ = d__1 * d__1 * r__;
/*< go to 10 >*/
goto L10;
/*< 20 pythag = p >*/
L20:
ret_val = p;
/*< return >*/
return ret_val;
/*< end >*/
} /* pythag_ */
#ifdef __cplusplus
}
#endif
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