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Topic: Matlab wrong cubic root
Replies: 3   Last Post: Dec 15, 2012 9:05 PM

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bartekltg

Posts: 31
Registered: 12/11/12
Re: Matlab wrong cubic root
Posted: Dec 15, 2012 9:05 PM
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W dniu 2012-12-15 19:19, sergio_r@mail.com pisze:
> Hello all,
>
> Is there a way of telling matlab to return first a real root
> instead of a complex one?
>
> For some strange reason matlab seems not to handle cubic roots
> properly. Apparently the default behaviour is to first
> report a complex root. Let's see two examples:
>

>>> (-1/2)^(1/3)
>
> ans =
>
> 0.3969 + 0.6874i


nthroot(-1/2,3)

>
>>> (-1/2)^(2/3)
>
> ans =
>
> -0.3150 + 0.5456i



nthroot(-1/2,3)^2

I'm afraid this is the simplest way, but I'm not sure.

bartekltg




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