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/* ../netlib/dlapy2.f -- translated by f2c (version 20100827). 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 "FLA_f2c.h" /* > \brief \b DLAPY2 returns sqrt(x2+y2). */
/* =========== DOCUMENTATION =========== */
/* Online html documentation available at */
/* http://www.netlib.org/lapack/explore-html/ */
/* > \htmlonly */
/* > Download DLAPY2 + dependencies */
/* > <a href="http://www.netlib.org/cgi-bin/netlibfiles.tgz?format=tgz&filename=/lapack/lapack_routine/dlapy2. f"> */
/* > [TGZ]</a> */
/* > <a href="http://www.netlib.org/cgi-bin/netlibfiles.zip?format=zip&filename=/lapack/lapack_routine/dlapy2. f"> */
/* > [ZIP]</a> */
/* > <a href="http://www.netlib.org/cgi-bin/netlibfiles.txt?format=txt&filename=/lapack/lapack_routine/dlapy2. f"> */
/* > [TXT]</a> */
/* > \endhtmlonly */
/* Definition: */
/* =========== */
/* DOUBLE PRECISION FUNCTION DLAPY2( X, Y ) */
/* .. Scalar Arguments .. */
/* DOUBLE PRECISION X, Y */
/* .. */
/* > \par Purpose: */
/* ============= */
/* > */
/* > \verbatim */
/* > */
/* > DLAPY2 returns sqrt(x**2+y**2), taking care not to cause unnecessary */
/* > overflow. */
/* > \endverbatim */
/* Arguments: */
/* ========== */
/* > \param[in] X */
/* > \verbatim */
/* > X is DOUBLE PRECISION */
/* > \endverbatim */
/* > */
/* > \param[in] Y */
/* > \verbatim */
/* > Y is DOUBLE PRECISION */
/* > X and Y specify the values x and y. */
/* > \endverbatim */
/* Authors: */
/* ======== */
/* > \author Univ. of Tennessee */
/* > \author Univ. of California Berkeley */
/* > \author Univ. of Colorado Denver */
/* > \author NAG Ltd. */
/* > \date September 2012 */
/* > \ingroup auxOTHERauxiliary */
/* ===================================================================== */
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 3.4.2) -- */
/* -- LAPACK is a software package provided by Univ. of Tennessee, -- */
/* -- Univ. of California Berkeley, Univ. of Colorado Denver and NAG Ltd..-- */
/* September 2012 */
/* .. Scalar Arguments .. */
/* .. */
/* ===================================================================== */
/* .. Parameters .. */
/* .. */
/* .. Local Scalars .. */
/* .. */
/* .. Intrinsic Functions .. */
/* .. */
/* .. Executable Statements .. */
xabs = f2c_abs(*x);
yabs = f2c_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_ */
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