Noel, thanks a lot. This will help me someday. But I have a question. When we run Shapiro-Wilk test, the homogenity of variances is a mandatory condition?
2010/4/12 Yvonnick Noel <yvonnick.n...@uhb.fr>: > Dear Iurie, > >> I want to run Shapiro-Wilk test for each variable in my dataset, each >> grouped by variable groupFactor. > > Note that, at least on a single dependent variable with a grouping variable, > a possible simplification may arise when homogeneity of variances is assumed > and reasonable. You may want to do a single normality test on group-centered > data : > > shapiro.test(residuals(lm(data[,1]~groupFactor))) > > > HTH, > > Yvonnick Noel > University of Brittany, Rennes 2 > France > ______________________________________________ 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.
