[R] odd behavior of numeric()

[Richard M. Heiberger]

> numeric(0.2*25)
[1] 0 0 0 0 0
> numeric((1-0.8)*25)
[1] 0 0 0 0
> print(c(0.2*25, (1-0.8)*25), digits=17)
[1] 5.0000000000000000 4.9999999999999991
> 0.2*25 - (1-0.8)*25
[1] 8.881784e-16
> as.integer(c(0.2*25, (1-0.8)*25), digits=17)
[1] 5 4
> ## See FAQ 7.31 for other examples of floating point behavior
>

On Wed, Apr 27, 2016 at 3:29 PM, Scott Rifkin <sarifkin at ucsd.edu> wrote:
> Why does:
>
>> numeric(0.2*25)
>
> return
>
> [1] 0 0 0 0 0
>
> but
>
>> numeric((1-0.8)*25)
>
> returns
>
> [1] 0 0 0 0
>
> [running version 3.2.0]
>
>
> [Apologies if this has been asked before - it's a hard question to find
> specific search terms for]
>
> Thanks,
> Scott
>
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