Doubt about nested aov output
Others may know the answer to your question, but I don't. However, since I have not seen a reply, I will offer a few comments: 1. What version of R are you using? I just tried superficially similar things with the examples in ?aov in R 2.1.1 patched and consistently got F and p values. 2. My preference for this kind of thing is to use lme in library(nlme) or lmer in library(lme4). Also, I highly recommend Pinheiro and Bates (2000) Mixed-Effects Models in S and S-Plus (Springer). 3. If still want to use aov and are getting this problem in R 2.1.1, could you please provide this list with a small, self contained example that displays the symptoms that concern you? And PLEASE do read the posting guide! "http://www.R-project.org/posting-guide.html". It might increase the speed and utility of replies. spencer graves
Ronaldo Reis-Jr. wrote:
Hi, I have two doubts about the nested aov output. 1) I have this:
anova.ratos <- aov(Glicogenio~Tratamento+Error(Tratamento/Rato/Figado)) summary(anova.ratos)
Error: Tratamento
Df Sum Sq Mean Sq
Tratamento 2 1557.56 778.78
Error: Tratamento:Rato
Df Sum Sq Mean Sq F value Pr(>F)
Residuals 3 797.67 265.89
Error: Tratamento:Rato:Figado
Df Sum Sq Mean Sq F value Pr(>F)
Residuals 12 594.0 49.5
Error: Within
Df Sum Sq Mean Sq F value Pr(>F)
Residuals 18 381.00 21.17
R dont make the F and P automatically, it is possible?
I Like an output like this:
Error: Tratamento
Df Sum Sq Mean Sq F value Pr(>F)
Tratamento 2 1557.56 778.78 2.929 0.197
Error: Tratamento:Rato
Df Sum Sq Mean Sq F value Pr(>F)
Residuals 3 797.67 265.89 5.372 0.0141
Error: Tratamento:Rato:Figado
Df Sum Sq Mean Sq F value Pr(>F)
Residuals 12 594.0 49.5 2.339 0.0503
Error: Within
Df Sum Sq Mean Sq F value Pr(>F)
Residuals 18 381.00 21.17
Why it not make automatic calculations? It is possible?
2) I can say that Error: Tratamento:Rato means an interaction between
Tratamento and Rato? Normally the : represents an interaction, but in this
output I think that it dont mean the interaction.
Any explanation are welcome.
Thanks
Ronaldo
Spencer Graves, PhD Senior Development Engineer PDF Solutions, Inc. 333 West San Carlos Street Suite 700 San Jose, CA 95110, USA spencer.graves at pdf.com www.pdf.com <http://www.pdf.com> Tel: 408-938-4420 Fax: 408-280-7915