Looking at the errors your code produces, it looks like you need to make Dock and Slip factors.
dock_2004_data$Dockf<-factor(dock_2004_data$Dock) dock_2004_data$Slipf<-factor(dock_2004_data$Slip) rich.aov <- aov(X.open ~ Dockf*Slipf, data=dock_2004_data) TukeyHSD(rich.aov, c("Dockf", "Slipf")) Jarrett Byrnes wrote: >Indeed, the following works as well >On Oct 26, 2005, at 5:23 PM, P Ehlers wrote: > > > >>fm1 <- aov(breaks ~ wool*tension, data = warpbreaks) >>TukeyHSD(fm1, c("wool","tension", "wool:tension")) >> >> > >However, when working with my own dataset, I get the following errors. > I have some inkling this may be due to a slightly unbalanced sample >size, but am uncertain of this. > > > rich.aov <- aov(X.open ~ Dock*Slip, data=dock_2004_data) > > TukeyHSD(rich.aov, c("Dock", "Slip")) > >Error in rep.int(n, length(means)) : unimplemented type 'NULL' in 'rep' >In addition: Warning messages: >1: non-factors ignored: Slip in: replications(paste("~", xx), data = mf) >2: non-factors ignored: Dock, Slip in: replications(paste("~", xx), >data = mf) > >I am pleased to know that these errors are not quite the > >______________________________________________ >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 > > > > ______________________________________________ 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