Hi Spencer, Em Dom 04 Set 2005 20:31, Spencer Graves escreveu: > 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.
I'm using the R version 2.1.1 on Linux Debian Version 2.1.1 (2005-06-20), ISBN 3-900051-07-0 > 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). Yes, this is my preference too, but I need aov for classes. > 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 I send the complete example. This is a example from the Crwaley's book (Statistical Computing: An introdution to data analysis using S-Plus. This is a classical experiment to show pseudoreplication, from Sokal and Rohlf (1995). In this experiments, It have 3 treatmens applied to 6 rats, for each rat it make 3 liver preparation and for each liver it make 2 readings of glycogen. This generated 6 pseudoreplication per rat. I'm interested on the effect os treatment on the glycogen readings. Look the R analyses: -------------------- > Glycogen <- c(131,130,131,125,136,142,150,148,140,143,160,150,157,145,154,142,147,153,151,155,147,147,162,152,134,125,138,138,135,136,138,140,139,138,134,127) > Glycogen [1] 131 130 131 125 136 142 150 148 140 143 160 150 157 145 154 142 147 153 151 [20] 155 147 147 162 152 134 125 138 138 135 136 138 140 139 138 134 127 > Treatment <- factor(rep(c(1,2,3),c(12,12,12))) > Treatment [1] 1 1 1 1 1 1 1 1 1 1 1 1 2 2 2 2 2 2 2 2 2 2 2 2 3 3 3 3 3 3 3 3 3 3 3 3 Levels: 1 2 3 > Rat <- factor(rep(rep(c(1,2),c(6,6)),3)) > Rat [1] 1 1 1 1 1 1 2 2 2 2 2 2 1 1 1 1 1 1 2 2 2 2 2 2 1 1 1 1 1 1 2 2 2 2 2 2 Levels: 1 2 > Liver <- factor(rep(rep(c(1,2,3),c(2,2,2)),6)) > Liver [1] 1 1 2 2 3 3 1 1 2 2 3 3 1 1 2 2 3 3 1 1 2 2 3 3 1 1 2 2 3 3 1 1 2 2 3 3 Levels: 1 2 3 > > ### Model made identical to the book > > model <- aov(Glycogen~Treatment/Rat/Liver+Error(Treatment/Rat/Liver)) > > summary(model) Error: Treatment Df Sum Sq Mean Sq Treatment 2 1557.56 778.78 Error: Treatment:Rat Df Sum Sq Mean Sq Treatment:Rat 3 797.67 265.89 Error: Treatment:Rat:Liver Df Sum Sq Mean Sq Treatment:Rat:Liver 12 594.0 49.5 Error: Within Df Sum Sq Mean Sq F value Pr(>F) Residuals 18 381.00 21.17 > > ### Model made by myself, I'm interested only in Treatment effects > > model <- aov(Glycogen~Treatment+Error(Treatment/Rat/Liver)) > > summary(model) Error: Treatment Df Sum Sq Mean Sq Treatment 2 1557.56 778.78 Error: Treatment:Rat Df Sum Sq Mean Sq F value Pr(>F) Residuals 3 797.67 265.89 Error: Treatment:Rat:Liver 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 -------------------- What it dont calculate the F and P for treatment? Thanks Ronaldo -- Tristezas não pagam dívidas. Nem bravatas, por falar nisso. --Millôr Fernandes Retirado de http://www.uol.com.br/millor -- |> // | \\ [***********************************] | ( õ õ ) [Ronaldo Reis Júnior ] |> V [UFV/DBA-Entomologia ] | / \ [36570-000 Viçosa - MG ] |> /(.''`.)\ [Fone: 31-3899-4007 ] | /(: :' :)\ [EMAIL PROTECTED] ] |>/ (`. `'` ) \[ICQ#: 5692561 | LinuxUser#: 205366 ] | ( `- ) [***********************************] |>> _/ \_Powered by GNU/Debian Woody/Sarge ______________________________________________ R-help@stat.math.ethz.ch mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide! http://www.R-project.org/posting-guide.html
