extraction of roots in R

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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?

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

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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
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

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