[R] Power of test

[Chuck Cleland]

Ethan Johnsons wrote:
> What would be the R formulae for a two-sided test?
> 
> I have a formula for a one-sided test:
> 
> powertest <- function(a,m0,m1,n,s){
> t1 = -qnorm(1-a)
> num = abs(m0-m1) * sqrt(n)
> t2 = num/s
> pow = pnorm(t1 + t2)
> }
> 
> Would you pls let me know if you know of?

RSiteSearch("power", restrict="functions") is helpful.  For a comparison
of two means, the most relevant hit is probably:

http://finzi.psych.upenn.edu/R/library/stats/html/power.t.test.html

> Thank you,
> 
> ej
> 
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Chuck Cleland, Ph.D.
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