Hi, Thanks Richard,
That was me playing with too many examples and having too many variables just lying around. Thanks for the tip though. On 22 August 2016 at 23:32, Bert Gunter <bgunter.4...@gmail.com> wrote: > Thanks, Rich. I didn't notice that! > > -- Bert > Bert Gunter > > "The trouble with having an open mind is that people keep coming along > and sticking things into it." > -- Opus (aka Berkeley Breathed in his "Bloom County" comic strip ) > > > On Mon, Aug 22, 2016 at 1:43 PM, Richard M. Heiberger <r...@temple.edu> > wrote: > > The problem is that you have 12 observations and 1+2+10=13 degrees of > freedom. > > There should be 1 + 2 + 8 = 11 degrees of freedom. > > Probably one of your variables is masked by something else in you > workspace. > > Protect yourself by using a data.frame > > > >> tmp <- data.frame(A=factor(c(1,1,1,1,1,1,2,2,2,2,2,2)), > > + B=factor(c(1,1,2,2,3,3,1,1,2,2,3,3)), > > + y=rnorm(12)) > >> mod <- aov(y ~ A+B, data=tmp) > >> summary(mod) > > Df Sum Sq Mean Sq F value Pr(>F) > > A 1 1.553 1.553 1.334 0.281 > > B 2 3.158 1.579 1.357 0.311 > > Residuals 8 9.311 1.164 > > > > On Mon, Aug 22, 2016 at 11:15 AM, Justin Thong <justinthon...@gmail.com> > wrote: > >> Something does not make sense in R. It has to do with the question of > >> balance and unbalance. > >> > >> *A<-factor(c(1,1,1,1,1,1,2,2,2,2,2,2))* > >> *B<-factor(c(1,1,2,2,3,3,1,1,2,2,3,3))* > >> *y<-rnorm(12)* > >> *mod<-aov(y~A+B)* > >> > >> I was under the impression that the design is balanced ie order does not > >> effect the sums of squares. However, when I compute the anova R reports > >> that the Estimated Effects are Unbalanced. I thought that when all > >> combinations of levels of A and B have equal replications then the > design > >> is called balanced. But, R tends to think that when not all levels of A > and > >> levels of B have equal replication, then the "Estimated Effects are > >> unbalanced".... Is this the same as the design being unbalanced? Because > >> for the example below, where the error occured, the order does not > matter > >> (which make me think that the design is balanced). > >> > >> > >> *Call:* > >> * aov(formula = y ~ A + B)* > >> > >> *Terms:* > >> * A B Residuals* > >> *Sum of Squares 0.872572 0.025604 16.805706* > >> *Deg. of Freedom 1 2 10* > >> > >> *Residual standard error: 1.296368* > >> *Estimated effects may be unbalanced* > >> -- > >> Yours sincerely, > >> Justin > >> > >> *I check my email at 9AM and 4PM everyday* > >> *If you have an EMERGENCY, contact me at +447938674419(UK) or > >> +60125056192(Malaysia)* > >> > >> [[alternative HTML version deleted]] > >> > >> ______________________________________________ > >> R-help@r-project.org mailing list -- To UNSUBSCRIBE and more, see > >> 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. > > > > ______________________________________________ > > R-help@r-project.org mailing list -- To UNSUBSCRIBE and more, see > > 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. > -- Yours sincerely, Justin *I check my email at 9AM and 4PM everyday* *If you have an EMERGENCY, contact me at +447938674419(UK) or +60125056192(Malaysia)* [[alternative HTML version deleted]] ______________________________________________ R-help@r-project.org mailing list -- To UNSUBSCRIBE and more, see 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.
