[R] Odp: ^ operator

[Petr PIKAL]

Hi

AFAIK, this is issue of the preference of operators. 

r-help-bounces at r-project.org napsal dne 16.11.2009 11:24:59:

> Hi,
> I want to apply ^ operator to a vector but it is applied to some of the 
> elements correctly and to some others, it generates NaN. Why is it not 
able to
> calculate -6.108576e-05^(1/3) even though it exists?
> 
> 
>  tmp
> [1] -6.108576e-05  4.208762e-05  3.547092e-05  7.171101e-04 
-1.600269e-03
> > tmp^(1/3)
> [1]        NaN 0.03478442 0.03285672 0.08950802        NaN

This computes (-a)^(1/3) which is not possible in real numbers. You have 
to use as.complex(tmp)^(1/3) to get a result.

> > -6.108576e-05^(1/3)
> [1] -0.03938341

this is actually
-(6.108576e-05^(1/3))

Regards
Petr


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