isnan(3) [ultrix man page]

isnan(3)						     Library Functions Manual							  isnan(3)

Name
       isnan - test for NaN

Syntax
       #include <math.h>

       int isnan (x)
       double x;

Description
       The  function  returns 1 if x is NaN (the IEEE floating point reserved not-a-number value) and zero otherwise.  On VAX, the return value is
       always zero.

																	  isnan(3)

isnan(3M)																 isnan(3M)

NAME

       isnan() - floating-point test for NaN

SYNOPSIS

       floating-type

DESCRIPTION

       The  macro determines whether its argument is a NaN.  The argument must be of floating type.  For HP Integrity servers, the argument can be
       any floating type.  For PA-RISC, the argument must be either or

       The macro implements the functionality recommended by the IEEE-754 standard for floating-point arithmetic.

       The macro replaces the and functions, which are obsolete and are no longer supported.

USAGE

       To use the macro, compile either with the default option or with the and options.  Make sure your program includes Link in the math library
       by specifying on the compiler or linker command line.

RETURN VALUE

       The macro returns a nonzero value if and only if its argument has a NaN value.  The macro raises no floating-point exceptions.

ERRORS

       No errors are defined.

EXAMPLES

       Take certain actions if is not a NaN:

SEE ALSO

       fpclassify(3M), isfinite(3M), isinf(3M), isnormal(3M), signbit(3M), math(5).

STANDARDS CONFORMANCE

																	 isnan(3M)