[R] extraction of roots in R

[Don McKenzie]

If you want complex roots, there is a post by Ravi Varadhan from  
2010, a reprint of which I found quickly by a google search at

http://r.789695.n4.nabble.com/finding-complex-roots-in-R-td2541514.html


On 1-Nov-13, at 11:20 AM, Don McKenzie wrote:

> If you just want the nth root of X, use X^(1/n)
>
> > x <- 256
> > x^(1/8)
> [1] 2
>
> > x <- -256
> > x^(1/8)
> [1] NaN
>
> It appears that you get the positive real root.
>
> Is this all you wanted?
>
>
> On 1-Nov-13, at 11:11 AM, Gary Dong wrote:
>
>> Dear R users,
>>
>> I wonder if R has a default function that I can use to do  
>> extraction of
>> roots.
>>
>> Here is an example:
>>
>> X                  N
>> 2.5              5
>> 3.4              7
>> 8.9              9
>> 6.4              1
>> 2.1              0
>> 1.1             2
>>
>> I want to calculate Y = root(X)^N, where N represents the power.  
>> what is
>> the easy way to do this?
>>
>> Thank you!
>>
>> Gary
>>
>> 	[[alternative HTML version deleted]]
>>
>> ______________________________________________
>> R-help at r-project.org mailing list
>> https://stat.ethz.ch/mailman/listinfo/r-help
>> PLEASE do read the posting guide http://www.R-project.org/posting- 
>> guide.html
>> and provide commented, minimal, self-contained, reproducible code.
>
>
>
>
>
> Don McKenzie
> Pacific Wildland Fire Sciences Lab
> US Forest Service
>
> Affiliate Professor
> School of Environmental and Forest Sciences
> University of Washington
>
> dmck at uw.edu
>
> ______________________________________________
> R-help at r-project.org mailing list
> https://stat.ethz.ch/mailman/listinfo/r-help
> PLEASE do read the posting guide http://www.R-project.org/posting- 
> guide.html
> and provide commented, minimal, self-contained, reproducible code.





Don McKenzie
Pacific Wildland Fire Sciences Lab
US Forest Service

Affiliate Professor
School of Environmental and Forest Sciences
University of Washington

dmck at uw.edu