Open System Services Library Calls Reference Manual (G06.29+, H06.08+, J06.03+)

isnan(3) OSS Library Calls Reference Manual
NAME
isnan - Tests whether a value is NaN (not a number)
LIBRARY
isnan( ) Macro
H-series and J-series native Guardian processes: $SYSTEM.ZDLLnnn.ZCREDLL
32-bit H-series and J-series OSS processes: /G/system/zdllnnn/zcredll
64-bit H-series and J-series OSS processes: /G/system/zdllnnn/ycredll
isnan( ) Function
G-series native Guardian processes: $SYSTEM.SYSnn.ZCRESRL
G-series native OSS processes: /G/system/sysnn/zcresrl
H-series and J-series native Guardian processes: $SYSTEM.ZDLLnnn.ZCREDLL
32-bit H-series and J-series OSS processes: /G/system/zdllnnn/zcredll
64-bit H-series and J-series OSS processes: /G/system/zdllnnn/ycredll
SYNOPSIS
isnan( ) Macro
#include <math.h>
int isnan(
floating-type x);
isnan( ) Function
#include <math.h>
int isnan(
double x);
PARAMETERS
isnan( ) Macro
floating-type Specifies the floating-type of x.
x Specifies a value of type floating-type.
isnan( ) Function
x Specifies a double-precision floating-point value.
DESCRIPTION
On systems running H06.21 or later H-series RVUs or J06.10 or later J-series RVUs, two options
are available to test whether a value is NaN (not a number):
isnan( ) Macro The isnan( ) macro conforms to the IEEE Std 1003.1, 2004 Edition. This macro
is implemented only for the IEEE_float floating-point option. Applications
using this macro cannot be compiled if the specified floating-point option is
Tandem_float. The argument can be any floating type.
isnan( ) Function
The isnan( ) function conforms to the XPG4 Version 2 specification when used
for IEEE floating-point format data. Because Tandem floating-point format does
not support NaN values, the isnan( ) function returns a value of 0 (zero) for Tan-
dem floating-point data. The argument must be a double-precision floating-point
value.
For systems running H06.21 or later H-series RVUs or J06.10 or later J-series RVUs, the isnan( )
macro is the applicable definition unless its use has been disabled by specifying the #undef isnan
4−50 Hewlett-Packard Company 527187-017