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 > > ______________________________________________ > R-help@stat.math.ethz.ch 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. -- Chuck Cleland, Ph.D. NDRI, Inc. 71 West 23rd Street, 8th floor New York, NY 10010 tel: (212) 845-4495 (Tu, Th) tel: (732) 512-0171 (M, W, F) fax: (917) 438-0894 ______________________________________________ R-help@stat.math.ethz.ch 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.