Dear people, I've a problem in doing a power calculation. In Fryer and Nicholson (1993), ICES J. mar. Sci. 50: 161-168 page 164 an example is given with the following characteristics T=5, points in time R=5, replicates Var.within=0.1 q=10, a 10% increase per year The degrees of freedom for the test are calculated as Vl=T*R-2=23 and the non-centrality parameter Dl=4.54. Using this they get a power of 0.53, but the result that I'm getting is 0.05472242.
I've tried this several ways in R, but I'm not able to come up with the same number. Am I doing something wrong in the calculation of the power? Here's my code: T<-5 R<-5 sigmasq<-0.1 q<-10 Vl<-(T*R)-2 Dl<-(R*(T-1)*T*(T+1)/(12*sigmasq))*(log(1+(q/100)))^2 #Dl result is still similar power.1<-1-pf(qf(.95,(T*R-2),1,ncp=0),(T*R-2),1,ncp=Dl) Thank you for any suggestions/help. I'm using R2.4.1, on windowsXP. Erik Meesters [[alternative HTML version deleted]] ______________________________________________ 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.