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msg00156
2011 Apr 13
1
error for ttest
Hello all,
I have arranged my data as per Dennis's suggestion in this post
http://www.mail-archive.com/r-help at r-project.org/msg107156.html.
the posted code works fine but when I try to apply it to my data, i get ">
u2 <- ddply(xxm, .(plateid, cytokine), as.data.frame.function(f))
Error in t.test.formula(conc ~ Self_T1D, data = df, na.rm = T) :
grouping factor must have exactly 2 levels".
Self_T1D has two levels...