X07ABF (PDF version)
X07 Chapter Contents
X07 Chapter Introduction
NAG Library Manual

NAG Library Routine Document

X07ABF

+ Contents

    1  Purpose
    7  Accuracy
    9  Example

1  Purpose

X07ABF determines whether a floating-point number is a NaN (Not A Number).

2  Specification

FUNCTION X07ABF ( X)
LOGICAL X07ABF
REAL (KIND=nag_wp)  X

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  Parameters

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  Further Comments

None.

9  Example

See Section 9 in X07AAF.

X07ABF (PDF version)
X07 Chapter Contents
X07 Chapter Introduction
NAG Library Manual

© The Numerical Algorithms Group Ltd, Oxford, UK. 2012