>>>>> Viechtbauer, Wolfgang (NP) writes: > Hi all, > Just noticed that the error that arises when calling t.test() with factors > could be a bit clearer:
>> t.test(factor(c(3,1,2,4,3,5,4,5)), factor(c(2,1,2,3,4,5))) > Error in var(x) : Calling var(x) on a factor x is defunct. > Use something like 'all(duplicated(x)[-1L])' to test for a constant vector. > In addition: Warning message: > In mean.default(x) : > argument is not numeric or logical: returning NA > Obviously, using factors as input is nonsense, but this might happen on > accident and then the error message could be a bit more on point. Similar for > aov(): >> aov(factor(c(3,1,2,4,3,5,4,5)) ~ factor(c(2,1,2,2,2,1,2,1))) > Call: > aov(formula = factor(c(3, 1, 2, 4, 3, 5, 4, 5)) ~ factor(c(2, > 1, 2, 2, 2, 1, 2, 1))) > Error in levels(x)[x] : > only 0's may be mixed with negative subscripts > In addition: Warning messages: > 1: In model.response(mf, "numeric") : > using type = "numeric" with a factor response will be ignored > 2: In Ops.factor(y, z$residuals) : '-' not meaningful for factors > Not a big deal and trying to catch all of the silly things users may > do is of course impossible, but for this one adding a check that the > (response) variable is actually numeric could be useful. Indeed. As always, the question is whether we want to give an error unless is.numeric, or ensure via as.numeric? Best -k > Best, > Wolfgang > -- > Wolfgang Viechtbauer, PhD, Statistician | Department of Psychiatry and > Neuropsychology | Maastricht University | PO Box 616 (VIJV1) | 6200 MD > Maastricht, The Netherlands | +31(43)3884170 | https://www.wvbauer.com > ______________________________________________ > R-devel@r-project.org mailing list > https://stat.ethz.ch/mailman/listinfo/r-devel ______________________________________________ R-devel@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-devel
