Hi, I run the following commands. 'A' has 3 levels and 'B' has 4 levels. Should there be totally 3+4 = 7 coefficients (A1, A2, A3, B1, B2, B3, B4)?
> a=3 > b=4 > n=1000 > A = rep(sapply(1:a,function(x){rep(x,n)}),b) > B = as.vector(sapply(sapply(1:b, function(x){rep(x,n)}), > function(x){rep(x,a)})) > Y = A + B + rnorm(a*b*n) > > fr = data.frame(Y=Y,A=as.factor(A),B=as.factor(B)) > afit=aov(Y ~ A + B - 1,fr) > afit$coefficients A1 A2 A3 B2 B3 B4 1.993067 2.969252 3.965888 1.005445 2.020717 3.023940 Regards, Peng ______________________________________________ R-help@r-project.org 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.