Weird double arithmetics in R

Asked May 23 '19 at 06:00

Active May 23 '19 at 06:05

Viewed 36 times

To reproduce:

> 1 - 0.9 - 0.1
[1] -2.775558e-17
> 1 - 0.1 - 0.9
[1] 0
> 1 + (-0.9 -0.1)
[1] 0
> 1 + -0.9 + -0.1
[1] -2.775558e-17
> 1 + (-0.9 + -0.1)
[1] 0
> - 0.9 - 0.1 + 1
[1] 0
> - 0.9 + 1 - 0.1
[1] -2.775558e-17
> - 0.9 + (1 - 0.1)
[1] 0

Can someone explain this behavior?

Add. info:

R version 3.6.0 (2019-04-26)
Platform: x86_64-pc-linux-gnu (64-bit)

edited May 23 '19 at 06:05

asked May 23 '19 at 06:00

Artem Klevtsov

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operator precedence? For me `1 - (0.9 +0.1)` or `1 -( 0.1 + 0.9)` both gives 0 – akrun May 23 '19 at 06:01
Once you know that `1 - 0.9` is not `1.0` (but `1 - 0.1` is `0.9`) the results make sense. – Amadan May 23 '19 at 06:08

Weird double arithmetics in R

0 Answers0