fpclassify(3) [netbsd man page]

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

NAME

     fpclassify -- classify real floating type

LIBRARY

     Standard C Library (libc, -lc)

SYNOPSIS

     #include <math.h>

     int
     fpclassify(real-floating x);

DESCRIPTION

     The fpclassify() macro performs classification of its argument x.	An argument represented in a format wider than its semantic type is con-
     verted to its semantic type first.  The classification is then based on the type of the argument.

   IEEE 754
	   FP_INFINITE	    infinity, either positive or negative
	   FP_NAN	    not-a-number (``NaN'')
	   FP_NORMAL	    normal
	   FP_SUBNORMAL     subnormal
	   FP_ZERO	    zero

   VAX
	   FP_ROP	    reserved operand (``ROP'')
	   FP_DIRTYZERO     dirty zero
	   FP_NORMAL	    finite
	   FP_ZERO	    true zero

RETURN VALUES

     The fpclassify() macro returns the value of the number classification macro appropriate to its argument x as described above.

ERRORS

     No errors are defined.

SEE ALSO

     isfinite(3), isnormal(3), math(3), signbit(3)

STANDARDS

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

BSD
								 January 14, 2004							       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.

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

     3BSD introduced isinf() and isnan() functions, which accepted double arguments; these have been superseded by the macros described above.

BSD
								 December 11, 2006							       BSD