HI,
May be the below links help:
http://r.789695.n4.nabble.com/TukeyHSD-troubles-td1570205.html
http://r.789695.n4.nabble.com/TukeyHSD-error-td3051059.html
A.K.
Hi
I'm trying to run a Tukey test on mortality data, where I want to test
whether mortality is influenced by the amount of copper (in an one-way ANOVA)
and the combination of copper and temperature (in a two-way ANOVA). These are my
formulas:
lm2<-lm(Mortality~Cu)
anova(lm2)
TukeyHSD(aov(Mortality~Cu))
lm2<-lm(Mortality~Cu+Temp+Cu:Temp)
anova(lm2)
TukeyHSD(aov(Mortality~Cu+Temp+Cu:Temp))
The ANOVA is no problem, but for both Tukey's, I get the following error
message:
Error in TukeyHSD.aov(aov(Mortality ~ Cu + Temp + Cu:Temp)) :
? no factors in the fitted model
In addition: Warning messages:
1: In replications(paste("~", xx), data = mf) : non-factors ignored:
Cu
2: In replications(paste("~", xx), data = mf) : non-factors ignored:
Temp
3: In replications(paste("~", xx), data = mf) :
? non-factors ignored: Cu, Temp
I've read on other posts that there should be a factor somewhere, but all my
data are numbers! I'm quite baffled and have no idea what to do next.
Thanks in advance for your help!
Lundill