/* dlapy3.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" #include "blaswrap.h" 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 3.2) -- */ /* Univ. of Tennessee, Univ. of California Berkeley and NAG Ltd.. */ /* November 2006 */ /* .. Scalar Arguments .. */ /* .. */ /* 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 .. */ /* .. */ /* .. Local Scalars .. */ /* .. */ /* .. Intrinsic Functions .. */ /* .. */ /* .. Executable Statements .. */ xabs = abs(*x); yabs = abs(*y); zabs = abs(*z__); /* Computing MAX */ d__1 = max(xabs,yabs); w = max(d__1,zabs); if (w == 0.) { /* W can be zero for max(0,nan,0) */ /* adding all three entries together will make sure */ /* NaN will not disappear. */ ret_val = xabs + yabs + zabs; } 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); } return ret_val; /* End of DLAPY3 */ } /* dlapy3_ */