dfM1<-19 # degrees of freedom of M1 |
dfM2<-26 # degrees of freedom of M2 |
delta<-dfM2*.05ˆ2 # define delta in the alternative hypothesis |
alpha<-.05 |
cv<-qchisq(1-alpha,df=dfM2-dfM1) # Critical value under the null hypothesis |
for (n in 1:100000) { |
power<-1-pchisq(cv,df=dfM2-dfM1,ncp=n*delta) |
if (power>=.80) break # reach the desirable power |
} |
N<-n+1 |
print(N) |