/* slapy3.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 slapy3_(real *x, real *y, real *z__) { /* System generated locals */ real ret_val, r__1, r__2, r__3; /* Builtin functions */ double sqrt(doublereal); /* Local variables */ real 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 */ /* ======= */ /* SLAPY3 returns sqrt(x**2+y**2+z**2), taking care not to cause */ /* unnecessary overflow. */ /* Arguments */ /* ========= */ /* X (input) REAL */ /* Y (input) REAL */ /* Z (input) REAL */ /* X, Y and Z specify the values x, y and z. */ /* ===================================================================== */ /* .. Parameters .. */ /* .. */ /* .. Local Scalars .. */ /* .. */ /* .. Intrinsic Functions .. */ /* .. */ /* .. Executable Statements .. */ xabs = dabs(*x); yabs = dabs(*y); zabs = dabs(*z__); /* Computing MAX */ r__1 = max(xabs,yabs); w = dmax(r__1,zabs); if (w == 0.f) { /* 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 */ r__1 = xabs / w; /* Computing 2nd power */ r__2 = yabs / w; /* Computing 2nd power */ r__3 = zabs / w; ret_val = w * sqrt(r__1 * r__1 + r__2 * r__2 + r__3 * r__3); } return ret_val; /* End of SLAPY3 */ } /* slapy3_ */