[R] Post Hoc Groupings

[Mark Lyman]

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
>
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