I am trying to conduct a robust ANOVA including post-hoc test using WRS2 package in R. My data structure is as such: 1 dependent variable (res) 2 independent variables: between (group) - within (bla) 1 ID variable to refer to subjects (id)
My code looks like this:
m1 <- WRS2::bwtrim(res ~ Group*Bla,id=id, data = fileHB)
Up until this point it works fine but when I try to check post hoc using this line of code:
sppba(res ~ Group*Bla,id,data = fileHB)
I receive the following error:
error in combn(levels(mf[, fixvar]), 2) : n < m
I don't know what to do here and I tried debugging but I cannot seem to find the error. I checked my data and everything is complete - so no missing data. Also, the indexing of subject etc. is correct. I would really aprreciate help on this issue.
I would be happy to get a response!