finite(3) [opendarwin man page]

FINITE(3)						   BSD Library Functions Manual 						 FINITE(3)

NAME

     finite -- returns 1 for finite x, 0 for infinite x and NaNs.

SYNOPSIS

     #include <math.h>

     int
     finite(double x);

DESCRIPTION

     The finite() function returns 1 if -infinity < x < +infinity. It returns 0 if x is +-infinity or a NaN.

STANDARDS

     The finite() function conforms to ISO/IEC 9899:1999(E).

BSD
								   July 2, 2003 							       BSD

HYPOT(3)						   BSD Library Functions Manual 						  HYPOT(3)

NAME

     hypot, hypotf, hypotl, cabs, cabsf, cabsl -- Euclidean distance and complex absolute value functions

LIBRARY

     Math Library (libm, -lm)

SYNOPSIS

     #include <math.h>

     double
     hypot(double x, double y);

     float
     hypotf(float x, float y);

     long double
     hypotl(long double x, long double y);

     #include <complex.h>

     double
     cabs(double complex z);

     float
     cabsf(float complex z);

     long double
     cabsl(long double complex z);

DESCRIPTION

     The hypot(), hypotf() and hypotl() functions compute the sqrt(x*x+y*y) in such a way that underflow will not happen, and overflow occurs only
     if the final result deserves it.  The cabs(), cabsf() and cabsl() functions compute the complex absolute value of z.

     hypot(infinity, v) = hypot(v, infinity) = +infinity for all v, including NaN.

ERROR (due to Roundoff, etc.)
     Below 0.97 ulps.  Consequently hypot(5.0, 12.0) = 13.0 exactly; in general, hypot and cabs return an integer whenever an integer might be
     expected.

NOTES

     As might be expected, hypot(v, NaN) and hypot(NaN, v) are NaN for all finite v.  But programmers might be surprised at first to discover that
     hypot(+-infinity, NaN) = +infinity.  This is intentional; it happens because hypot(infinity, v) = +infinity for all v, finite or infinite.
     Hence hypot(infinity, v) is independent of v.  Unlike the reserved operand fault on a VAX, the IEEE NaN is designed to disappear when it
     turns out to be irrelevant, as it does in hypot(infinity, NaN).

SEE ALSO

     carg(3), math(3), sqrt(3)

STANDARDS

     The hypot(), hypotf(), hypotl(), cabs(), cabsf(), and cabsl() functions conform to ISO/IEC 9899:1999 (``ISO C99'').

HISTORY

     Both a hypot() function and a cabs() function appeared in Version 7 AT&T UNIX.

BSD
								  March 30, 2008							       BSD