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NAG Library Routine Document

x07abf (is_nan)

NAG Library Manual, Mark 26
NAG AD Library Manual, Mark 26
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▸▿ Contents

© The Numerical Algorithms Group Ltd. 2018

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 <nagmk26.h>
Nag_Boolean  x07abf_ (const double *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
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 26
NAG AD Library Manual, Mark 26
NAG C Library Manual, Mark 26
X07 (ieee) Chapter Contents
X07 (ieee) Chapter Introduction
© The Numerical Algorithms Group Ltd. 2018