isfinite(3) [netbsd man page]

ISFINITE(3)						   BSD Library Functions Manual 					       ISFINITE(3)

NAME

     isfinite -- test for finite value

LIBRARY

     Standard C Library (libc, -lc)

SYNOPSIS

     #include <math.h>

     int
     isfinite(real-floating x);

DESCRIPTION

     The isfinite() determines whether its argument x has a finite value.  An argument represented in a format wider than its semantic type is
     converted to its semantic type first.  The determination is then based on the type of the argument.

   IEEE 754
     It is determined whether the value of x is zero, subnormal, or normal, and neither infinite nor NaN.

   VAX
     It is determined whether the value of x is true zero or finite, and neither dirty zero nor ROP.

RETURN VALUES

     The isfinite() macro returns a non-zero value if the value of x is finite.  Otherwise 0 is returned.

ERRORS

     No errors are defined.

SEE ALSO

     finite(3), fpclassify(3), isnormal(3), math(3), signbit(3)

STANDARDS

     The isfinite() macro conforms to ISO/IEC 9899:1999 (``ISO C99'').

BSD
								  August 6, 2011							       BSD

FPCLASSIFY(3)						   BSD Library Functions Manual 					     FPCLASSIFY(3)

NAME

     fpclassify, isfinite, isinf, isnan, isnormal -- classify a floating-point number

LIBRARY

     Math Library (libm, -lm)

SYNOPSIS

     #include <math.h>

     int
     fpclassify(real-floating x);

     int
     isfinite(real-floating x);

     int
     isinf(real-floating x);

     int
     isnan(real-floating x);

     int
     isnormal(real-floating x);

DESCRIPTION

     The fpclassify() macro takes an argument of x and returns one of the following manifest constants.

     FP_INFINITE   Indicates that x is an infinite number.

     FP_NAN	   Indicates that x is not a number (NaN).

     FP_NORMAL	   Indicates that x is a normalized number.

     FP_SUBNORMAL  Indicates that x is a denormalized number.

     FP_ZERO	   Indicates that x is zero (0 or -0).

     The isfinite() macro returns a non-zero value if and only if its argument has a finite (zero, subnormal, or normal) value.  The isinf(),
     isnan(), and isnormal() macros return non-zero if and only if x is an infinity, NaN, or a non-zero normalized number, respectively.

     The symbol isnanf() is provided as an alias to isnan() for compatibility, and its use is deprecated.  Similarly, finite() and finitef() are
     deprecated versions of isfinite().

SEE ALSO

     isgreater(3), math(3), signbit(3)

STANDARDS

     The fpclassify(), isfinite(), isinf(), isnan(), and isnormal() macros conform to ISO/IEC 9899:1999 (``ISO C99'').

HISTORY

     The fpclassify(), isfinite(), isinf(), isnan(), and isnormal() macros were added in FreeBSD 5.1.  3BSD introduced isinf() and isnan() func-
     tions, which accepted double arguments; these have been superseded by the macros described above.

BSD
								 January 26, 2005							       BSD