Dear Sir, Many thanks for your reply.
I have a query. I have a whole set of distributions which should be made normal / homoscedastic. Take for instance the warpbreaks data set. We have the following boxplots for the warpbreaks dataset: a. boxplot(breaks ~ wool) b. boxplot(breaks ~ tension) c. boxplot(breaks ~ interaction(wool,tension)) d. boxplot(breaks ~ wool @ each level of tension) e. boxplot(breaks ~ tension @ each level of wool) Now should we not be making a-e normal and homoscedastic? Should we not make a giant collection of boxplots from a-e and use the SpreadLevelPlot on this entire collection? A second query : (d) and (e) are the distribution of the simple effects of factor wool and tension @ each level of the other. Is that correct? Are (a) and (b) the distribution of the main effect of wool and tension? Please confirm. Best Regards, Ashim On Sun, Jan 7, 2018 at 8:05 PM, Fox, John <j...@mcmaster.ca> wrote: > Dear Ashim, > > Try spreadLevelPlot(breaks ~ interaction(tension, wool), data=warpbreaks) . > > I hope this helps, > John > > ----------------------------- > John Fox, Professor Emeritus > McMaster University > Hamilton, Ontario, Canada > Web: socialsciences.mcmaster.ca/jfox/ > > > > > -----Original Message----- > > From: R-help [mailto:r-help-boun...@r-project.org] On Behalf Of Ashim > > Kapoor > > Sent: Sunday, January 7, 2018 12:08 AM > > To: r-help@r-project.org > > Subject: [R] SpreadLevelPlot for more than one factor > > > > Dear All, > > > > I want a transformation which will make the spread of the response at > all > > combinations of 2 factors the same. > > > > See for example : > > > > boxplot(breaks ~ tension * wool, warpbreaks) > > > > The closest I can do is : > > > > spreadLevelPlot(breaks ~tension , warpbreaks) spreadLevelPlot(breaks ~ > wool , > > warpbreaks) > > > > I want to do : > > > > spreadLevelPlot(breaks ~tension * wool, warpbreaks) > > > > But I get : > > > > > spreadLevelPlot(breaks ~tension * wool , warpbreaks) > > Error in spreadLevelPlot.formula(breaks ~ tension * wool, warpbreaks) : > > right-hand side of model has more than one variable > > > > What is the corresponding appropriate function for 2 factors ? > > > > Many thanks, > > Ashim > > > > [[alternative HTML version deleted]] > > > > ______________________________________________ > > R-help@r-project.org mailing list -- To UNSUBSCRIBE and more, see > > 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. > [[alternative HTML version deleted]] ______________________________________________ R-help@r-project.org mailing list -- To UNSUBSCRIBE and more, see 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.