Re: [R] cube root

From: Berend Hasselman <bhh_at_xs4all.nl>
Date: Sat, 16 Apr 2011 23:00:59 -0700 (PDT)

Branimir K. Hackenberger wrote:
>
> This is some interesting:
>

>> -8^(1/3)

>
> [1] -2
>
>> x=(-8:8)

>
>> y=x^(1/3)

>
>> y

>
> [1] NaN NaN NaN NaN NaN NaN NaN
> NaN
> 0.000000 1.000000
>
> [11] 1.259921 1.442250 1.587401 1.709976 1.817121 1.912931 2.000000
> So, can anybody explain this?! (Why is x[1]^(1/3)=y[1]=NaN, but
> -8^(1/3)=-2?)
>

Operator precedence.

See R FAQ 7.33 Why are powers of negative numbers wrong?

Berend

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Received on Sun 17 Apr 2011 - 06:02:44 GMT

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