Good Night I made different test to check normality and multinormality in my dataset, but I don´t know which test is better. To verify univariate normality I checked: shapiro.test, cvm.test, ad.test, lillie.test, sf.test or jaque.bera.test and To verify multivariate normal distribution I use mardia, mvShapiro.Test, mvsf, mshapiro.test, mvnorm.e. I have a dataset with almost 1000 data and 9 variables, in both cases the result is non-normality. For this reason, I transformed data with bcPower function and I want to check normality again. I really appreciate your help. Thanks. [[alternative HTML version deleted]]
Hi Sindy, you might try Snows penultimate normality test from the TeachingDemos package. But read the help file carefully. http://www.inside-r.org/packages/cran/TeachingDemos/docs/SnowsPenultimateNormalityTest cheers. Am 28.03.2012 02:32, schrieb Sindy Carolina Lizarazo:> Good Night > > I made different test to check normality and multinormality in my dataset, > but I don?t know which test is better. > > To verify univariate normality I checked: shapiro.test, cvm.test, ad.test, > lillie.test, sf.test or jaque.bera.test and > To verify multivariate normal distribution I use mardia, mvShapiro.Test, > mvsf, mshapiro.test, mvnorm.e. > > I have a dataset with almost 1000 data and 9 variables, in both cases the > result is non-normality. For this reason, I transformed data with bcPower > function and I want to check normality again. > > I really appreciate your help. > Thanks. > > [[alternative HTML version deleted]] > > > > > ______________________________________________ > R-help at 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.-- Eik Vettorazzi Department of Medical Biometry and Epidemiology University Medical Center Hamburg-Eppendorf Martinistr. 52 20246 Hamburg T ++49/40/7410-58243 F ++49/40/7410-57790 -- Pflichtangaben gem?? Gesetz ?ber elektronische Handelsregister und Genossenschaftsregister sowie das Unternehmensregister (EHUG): Universit?tsklinikum Hamburg-Eppendorf; K?rperschaft des ?ffentlichen Rechts; Gerichtsstand: Hamburg Vorstandsmitglieder: Prof. Dr. Guido Sauter (Vertreter des Vorsitzenden), Dr. Alexander Kirstein, Joachim Pr?l?, Prof. Dr. Dr. Uwe Koch-Gromus
On 3/27/2012 8:32 PM, Sindy Carolina Lizarazo wrote:> Good Night > > I made different test to check normality and multinormality in my dataset, > but I don?t know which test is better. > > To verify univariate normality I checked: shapiro.test, cvm.test, ad.test, > lillie.test, sf.test or jaque.bera.test and > To verify multivariate normal distribution I use mardia, mvShapiro.Test, > mvsf, mshapiro.test, mvnorm.e. > > I have a dataset with almost 1000 data and 9 variables, in both cases the > result is non-normality. For this reason, I transformed data with bcPower > function and I want to check normality again.Univariate tests of normality are subsumed within the multivariate tests, so there is no real need for the former. That being said, many of the tests are quite sensitive to mild or small departures from multivariate normality, such that would have little real impact on the validity of an analysis. You may find it more useful to carry out a graphical analysis, such as with normal QQ plots, or the multivariate generalization with is a plot of Mahalanobis squared distances of all observations from their centroid vs. corresponding quantiles of the Chisquare distribution with p=9 df. [As a courtesy to readers, you might cite the packages from which you've used these functions.] -Michael -- Michael Friendly Email: friendly AT yorku DOT ca Professor, Psychology Dept. York University Voice: 416 736-5115 x66249 Fax: 416 736-5814 4700 Keele Street Web: http://www.datavis.ca Toronto, ONT M3J 1P3 CANADA