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/* lapack/double/dlapy3.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 DLAPY3( X, Y, Z ) >*/
doublereal dlapy3_(doublereal *x, doublereal *y, doublereal *z__)
{
/* System generated locals */
doublereal ret_val, d__1, d__2, d__3;
/* Builtin functions */
double sqrt(doublereal);
/* Local variables */
doublereal 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 .. */
/*< DOUBLE PRECISION X, Y, Z >*/
/* .. */
/* Purpose */
/* ======= */
/* DLAPY3 returns sqrt(x**2+y**2+z**2), taking care not to cause */
/* unnecessary overflow. */
/* Arguments */
/* ========= */
/* X (input) DOUBLE PRECISION */
/* Y (input) DOUBLE PRECISION */
/* Z (input) DOUBLE PRECISION */
/* X, Y and Z specify the values x, y and z. */
/* ===================================================================== */
/* .. Parameters .. */
/*< DOUBLE PRECISION ZERO >*/
/*< PARAMETER ( ZERO = 0.0D0 ) >*/
/* .. */
/* .. Local Scalars .. */
/*< DOUBLE PRECISION W, XABS, YABS, ZABS >*/
/* .. */
/* .. Intrinsic Functions .. */
/*< INTRINSIC ABS, MAX, SQRT >*/
/* .. */
/* .. Executable Statements .. */
/*< XABS = ABS( X ) >*/
xabs = abs(*x);
/*< YABS = ABS( Y ) >*/
yabs = abs(*y);
/*< ZABS = ABS( Z ) >*/
zabs = abs(*z__);
/*< W = MAX( XABS, YABS, ZABS ) >*/
/* Computing MAX */
d__1 = max(xabs,yabs);
w = max(d__1,zabs);
/*< IF( W.EQ.ZERO ) THEN >*/
if (w == 0.) {
/*< DLAPY3 = ZERO >*/
ret_val = 0.;
/*< ELSE >*/
} else {
/*< >*/
/* Computing 2nd power */
d__1 = xabs / w;
/* Computing 2nd power */
d__2 = yabs / w;
/* Computing 2nd power */
d__3 = zabs / w;
ret_val = w * sqrt(d__1 * d__1 + d__2 * d__2 + d__3 * d__3);
/*< END IF >*/
}
/*< RETURN >*/
return ret_val;
/* End of DLAPY3 */
/*< END >*/
} /* dlapy3_ */
#ifdef __cplusplus
}
#endif
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