Hi Sven, I think that you could also use `lme', i.e., something like:
library(nlme) lme1 <- lme(Points~Game, random=~1|Store, data=kh.df) lme2 <- lme(Points~Game, random=~1|Store/Game, data=kh.df) anova(lme1) anova(lme2) anova(lme1, lme2) I hope this helps. Best, Dimitris ---- Dimitris Rizopoulos Doctoral Student Biostatistical Centre School of Public Health Catholic University of Leuven Address: Kapucijnenvoer 35, Leuven, Belgium Tel: +32/16/396887 Fax: +32/16/337015 Web: http://www.med.kuleuven.ac.be/biostat/ http://www.student.kuleuven.ac.be/~m0390867/dimitris.htm ----- Original Message ----- From: "Sven Garbade" <[EMAIL PROTECTED]> To: <[EMAIL PROTECTED]> Sent: Friday, July 16, 2004 10:36 AM Subject: [R] Fixed and random factors in aov() > Hi, > I'm confused about how to specify random and fixed factors in an aov() > term. I tried to reproduce a textbook example: One fixed factor (Game, 4 > levels) and one random factor (Store, 12 levels), response is Points. > The random factor Store is nested in Game. I tried > > > str(kh.df) > `data.frame': 48 obs. of 4 variables: > $ Subj : Factor w/ 48 levels "vp1","vp10","vp11",..: 1 12 23 34 44... > $ Game : Factor w/ 4 levels "S1","S2","S3",..: 1 1 1 1 1 1 1 1 ... > $ Store : Factor w/ 12 levels "KH1","KH10","KH11",..: 1 1 1 1 5 ... > $ Points: num 7 9 12 7 6 5 8 6 9 6 ... > > > summary(aov(Points ~ Game + Error(Game:Store),dat=kh.df)) > > Error: Game:Store > Df Sum Sq Mean Sq F value Pr(>F) > Game 3 391.50 130.50 5.9771 0.01934 * > Residuals 8 174.67 21.83 > --- > Signif. codes: 0 `***' 0.001 `**' 0.01 `*' 0.05 `.' 0.1 ` ' 1 > > Error: Within > Df Sum Sq Mean Sq F value Pr(>F) > Residuals 36 149.500 4.153 > Warning message: > Error model is singular in: aov(Points ~ Game + Error(Game:Store), dat = > kh.df) > > which gives me the correct F-statistic for the fixed factor Game and > > > summary(aov(Points ~ Game + Game:Store,dat=kh.df)) > Df Sum Sq Mean Sq F value Pr(>F) > Game 3 391.50 130.50 31.4247 3.707e-10 *** > Game:Store 8 174.67 21.83 5.2575 0.0002126 *** > Residuals 36 149.50 4.15 > --- > Signif. codes: 0 `***' 0.001 `**' 0.01 `*' 0.05 `.' 0.1 ` ' 1 > > which calcultes the correct Game:Store F statistic but the incorrect > F value for Game (because its a fixed factor). I'm wondering about how > to specify a correct model formula for the fixed and random factors with > an appropiate Error() term. > > Thanks, Sven > > ______________________________________________ > [EMAIL PROTECTED] mailing list > https://www.stat.math.ethz.ch/mailman/listinfo/r-help > PLEASE do read the posting guide! http://www.R-project.org/posting-guide.html ______________________________________________ [EMAIL PROTECTED] mailing list https://www.stat.math.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide! http://www.R-project.org/posting-guide.html
