isinf(), isinff(), isnan(), isnanf()

test for infinity or not-a-number 

Function

SYNOPSIS

#include <math.h>

int isinf(double x)

int isnan(double x)

int isinff(float x)

int isnanf(float x)

DESCRIPTION

The isinf() function returns 1 if the number x is Infinity, otherwise 0.

The isnan() function returns 1 if the number is NaN, otherwise 0.

The isinff() and isnanf() functions are single-precision versions of isinf() and isnan(), respectively.

PARAMETERS

x 

Is the floating point value to test.

RETURN VALUES

The isinf() function returns non-zero if x is +Infinity or -Infinity. Otherwise 0 is returned.

The isnan() function returns non-zero if x is NaN. Otherwise 0 is returned.

CONFORMANCE

UNIX 98.

MULTITHREAD SAFETY LEVEL

MT-Safe.

PORTING ISSUES

None.

AVAILABILITY

PTC MKS Toolkit for Professional Developers
PTC MKS Toolkit for Professional Developers 64-Bit Edition
PTC MKS Toolkit for Enterprise Developers
PTC MKS Toolkit for Enterprise Developers 64-Bit Edition

SEE ALSO

Functions:
math()

IEEE Standard for Binary Floating-Point Arithmetic, Std 754-1985, ANSI

PTC MKS Toolkit 10.4 Documentation Build 39.