NAG FL Interface
x07aaf (is_​finite)

1 Purpose

x07aaf determines whether a floating-point number is finite.

2 Specification

Fortran Interface
Function x07aaf ( x)
Logical :: x07aaf
Real (Kind=nag_wp), Intent (In) :: x
C Header Interface
#include <nag.h>
Nag_Boolean  x07aaf_ (const double *x)
The routine may be called by the names x07aaf or nagf_ieee_is_finite.

3 Description

x07aaf returns .TRUE. if and only if x is finite, 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


7 Accuracy

Not applicable.

8 Parallelism and Performance

x07aaf is not threaded in any implementation.

9 Further Comments

This routine will return .FALSE. if the argument x is either infinite or a NaN (Not A Number).

10 Example

This program creates various infinities, NaNs and normal numbers and distinguishes between them.

10.1 Program Text

Program Text (x07aafe.f90)

10.2 Program Data


10.3 Program Results

Program Results (x07aafe.r)