x02ajf (PDF version)
X02 (machine) Chapter Contents
X02 (machine) Chapter Introduction
NAG Library Manual

NAG Library Routine Document

x02ajf  (precision)

▸▿ Contents

    1  Purpose
    2  Specification
    3  Description
    4  References
    5  Arguments
    6  Error Indicators and Warnings
    7  Accuracy
    8  Parallelism and Performance
    9  Further Comments
▸▿ 10  Example

1
Purpose

x02ajf returns ε, the value machine precision.

2
Specification

Fortran Interface
Function x02ajf ( )
Real (Kind=nag_wp):: x02ajf
C Header Interface
#include nagmk26.h
double  x02ajf_ ()

3
Description

x02ajf returns machine precision, computed as ε = 12 × b1-p , where b is the arithmetic base (see x02bhf) and p is the number of significant base-b digits (see x02bjf).
It is important to note that the definition of ε here differs from that in ISO Fortran 95 (1997).

4
References

ISO Fortran 95 (1997) ISO Fortran 95 programming language (ISO/IEC 1539–1:1997)

5
Arguments

None.

6
Error Indicators and Warnings

None.

7
Accuracy

None.

8
Parallelism and Performance

x02ajf is not threaded in any implementation.

9
Further Comments

None.

10
Example

This example prints the values of all the functions in Chapter X02. The results will vary from one implementation of the Library to another.

10.1
Program Text

Program Text (x02ajfe.f90)

10.2
Program Data

None.

10.3
Program Results

Program Results (x02ajfe.r)

x02ajf (PDF version)
X02 (machine) Chapter Contents
X02 (machine) Chapter Introduction
NAG Library Manual
© The Numerical Algorithms Group Ltd, Oxford, UK. 2017