On Apr 17, 2013, at 16:47 , Rémi Lesmerises wrote: > Dear all, > > I'm trying to compare two sets of variables, the first set is composed > exclusively of numerical variables and the second regroups factors and > numerical variables. I can't use a Manova because of this inclusion of > numerical variables in the second set. The solution should be to perform a > Mancova, but I didn't find any package that allow this type of test. > > I've already looked in this forum and on the net to find answers, but the > only thing I've found is the following: > > > lm(as.matrix(Y) ~ x+z) > x and z could be numerical and factors. The problem with that is it actually > only perform a succession of lm (or glm), one for each numerical variable > contained in the Y matrix. It is not a true MANCOVA that do a significance > test (most often a Wald test) for the overall two sets comparison. Such a > test is available in SPSS and SAS, but I really want to stay in R! Someone > have any idea?
You can fit two models and compare them with (say) fit1 <- lm(as.matrix(Y) ~ x+z) fit2 <- lm(as.matrix(Y) ~ x) anova(fit1, fit2, test="Wilks") or, removing terms sequentially: anova(fit1, test="Wilks") > > Thanks in advance for your help! > > Rémi Lesmerises, biol. M.Sc., > Candidat Ph.D. en Biologie > Université du Québec à Rimouski > remilesmeri...@yahoo.ca > > [[alternative HTML version deleted]] > > ______________________________________________ > R-help@r-project.org mailing list > https://stat.ethz.ch/mailman/listinfo/r-help > PLEASE do read the posting guide http://www.R-project.org/posting-guide.html > and provide commented, minimal, self-contained, reproducible code. -- Peter Dalgaard, Professor Center for Statistics, Copenhagen Business School Solbjerg Plads 3, 2000 Frederiksberg, Denmark Phone: (+45)38153501 Email: pd....@cbs.dk Priv: pda...@gmail.com ______________________________________________ R-help@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.
