thank you for your reply. However, your remark was not so clear to me so I attach a short script I tried to launch. The comparison between results got from MANOVA() call with the non-standardized and standardized version of the same data frame, convinced me that it is not necessary to standardize data before calling MANOVA. The only difference you get is in the residuals values, of course. Could you kindly confirm my conclusion?
All the best, Sergio Fonda ______________________ set.seed(1234) # non- standardized series x1 = rnorm(n=10, mean=50, sd=11) x2 = rnorm(n=10, mean=93, sd=23) x1 = rnorm(n=10, mean=217, sd=52) fact= rep(1:2,20) glob1=data.frame(cbind(x1,x2,x3,fact)) fitta1=manova(cbind(x1,x2,x3)~fact, data=glob1) fitta1.wilks=summary(fitta1, test="Wilks") summary.aov(fitta1) #after standardization x.stand=scale(glob1[,-4]) glob2=data.frame(x.stand,fact) fitta2=manova(cbind(x1,x2,x3)~fact, data=glob2) fitta2.wilks=summary(fitta2, test="Wilks") summary.aov(fitta2) 2013/11/4 Sergio Fonda <sergio.fond...@gmail.com>: > Hi, > I'm not able to get information about the following question: > > is the variables standardization a default option in manova() (stats package)? > Or if you want to compare variables with different units or scales and > rather different variances, you have to previously standardize the > variables ? > > Thanks a lot for any help, > > Sergio Fonda > www.unimore.it ______________________________________________ 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.