Dear Sir, Many thanks and Best Regards, Ashim.
On Sun, Jan 14, 2018 at 9:05 PM, Fox, John <j...@mcmaster.ca> wrote: > Dear Ashim, > > I’ll address your questions briefly but they’re really not appropriate for > this list, which is for questions about using R, not general statistical > questions. > > (1) The relevant distribution is within cells of the wool x tension > cross-classification because it’s the deviations from the cell means that > are supposed to be normally distributed with equal variance. In the > warpbreaks data there are only 9 cases per cell. If you examine all of > these deviations simultaneously, that’s equivalent to examining the > residuals from the two-way ANOVA model fit to the data. > > (2) Yes, (d) and (e) visualize simple effects, and (a) and (b) visualize > main effects, the latter only because the data are balanced. > > Best, > John > > ------------------------------------- > John Fox, Professor Emeritus > McMaster University > Hamilton, Ontario, Canada > Web: http://socserv.mcmaster.ca/jfox/ > > > > > On 2018-01-09, 10:18 AM, "Ashim Kapoor" <ashimkap...@gmail.com> wrote: > > >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/ <http://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 > ><https://stat.ethz.ch/mailman/listinfo/r-help> > >> PLEASE do read the posting guide > >http://www.R-project.org/posting- <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.
