Dear Varina, I think that you may be confusing the Anova() function in the car package (which takes an idesign argument) with the standard R anova() function.
I hope this helps, John -------------------------------- John Fox Senator William McMaster Professor of Social Statistics Department of Sociology McMaster University Hamilton, Ontario, Canada http://socserv.mcmaster.ca/jfox > -----Original Message----- > From: r-help-boun...@r-project.org [mailto:r-help-bounces@r- > project.org] On Behalf Of Varina Crisfield > Sent: November-18-11 10:11 AM > To: r-help@r-project.org > Subject: [R] One-way repeated measures ANOVA > > Hi all, > > I'm trying to run a repeated measures ANOVA on some univariate > ecological data that was collected over two growing seasons. I ran the > test using the methodology found on this website: > > http://rtutorialseries.blogspot.com/2011/02/r-tutorial-series-one-way- > repeated.html > > Upon running the actual ANOVA I got this error message: > > "> rmanova=anova(yearmodel, idata=yearframe, idesign=~yearfactor) > Warning message: > In function (object, ..., test = c("Pillai", "Wilks", "Hotelling- > Lawley", : > models with response "NULL" removed because response differs from > model 1" > > And the p-values I get in the anova summary are completely off, judging > by the t-tests I did on the same data. > > The dataset is small (n=6) and was arranged so that the data from the > two different years was arranged in two columns ("2010", "2011). > > I've pasted the rest of the code below for reference. I'd appreciate > any suggestions as to what the issue here is! > > Thanks, > Varina > > transect=read.csv("Transect data.csv") > > attach(transect) > > > replicates=c(1,2) > > yearfactor=as.factor(replicates) > > yearframe=data.frame(yearfactor) > > yearbind=cbind(transect$TP10, transect$TP11) > > yearmodel=lm(yearbind~1) > > > rmanova=anova(yearmodel, idata=yearframe, idesign=~yearfactor) > > summary(rmanova) > > [[alternative HTML version deleted]] > > ______________________________________________ > 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. ______________________________________________ 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.
