NAG Library Manual, Mark 27
Interfaces:  FL   CL   CPP   AD 
NAG FL Interface Introduction
X07 (Ieee) Chapter Contents
X07 (Ieee) Chapter Introduction
x07ab:  FL   CL   CPP   AD 

NAG FL Interface
x07abf (is_​nan)

NAG Library Manual, Mark 27
Interfaces:  FL   CL   CPP   AD 
NAG FL Interface Introduction
X07 (Ieee) Chapter Contents
X07 (Ieee) Chapter Introduction
x07ab:  FL   CL   CPP   AD 

▸▿ Contents

© The Numerical Algorithms Group Ltd. 2019

1 Purpose

x07abf determines whether a floating-point number is a NaN (Not A Number).

2 Specification

Fortran Interface
Function x07abf ( x)
Logical :: x07abf
Real (Kind=nag_wp), Intent (In) :: x
C Header Interface
#include <nag.h>
Nag_Boolean  x07abf_ (const double *x)
The routine may be called by the names x07abf or nagf_ieee_is_nan.

3 Description

x07abf returns .TRUE. if and only if x is a NaN, and returns .FALSE. otherwise.

4 References

IEEE (2008) Standard for Floating-Point Arithmetic IEEE Standard 754-2008 IEEE, New York.

5 Arguments

1: x – Real (Kind=nag_wp) Input
On entry: the number whose status is to be determined.

6 Error Indicators and Warnings

None.

7 Accuracy

Not applicable.

8 Parallelism and Performance

x07abf is not threaded in any implementation.

9 Further Comments

None.

10 Example

See Section 10 in x07aaf.
NAG Library Manual, Mark 27
Interfaces:  FL   CL   CPP   AD 
NAG FL Interface Introduction
X07 (Ieee) Chapter Contents
X07 (Ieee) Chapter Introduction
x07ab:  FL   CL   CPP   AD 
© The Numerical Algorithms Group Ltd. 2019