On Jan 10, 2012, at 21:30 , gaiarrido wrote: > I've made fligner test with the same data, changing the orders of the > variables, and this what i get > >> fligner.test(rojos~edadysexo*zona*ano*estacion) > > Fligner-Killeen test of homogeneity of variances > > data: rojos by edadysexo by zona by ano by estacion > Fligner-Killeen:med chi-squared = 15.7651, df = 2, p-value = 0.0003773 > >> fligner.test(rojos~ano*edadysexo*zona*estacion) > > Fligner-Killeen test of homogeneity of variances > > data: rojos by ano by edadysexo by zona by estacion > Fligner-Killeen:med chi-squared = 86.5317, df = 3, p-value < 2.2e-16 > > Different results with the same variables!!! Why? i try to find an answer, > but i really surprised
You are assuming that you can put interactions on the rhs of formulas, but nowhere in the documentation does it say that that should work. All examples have a single grouping variables. So the behavior is undefined. As far as I can see, only the _first_ variable is actually being used for grouping. Arguably, there is potential for better argument checking in fligner.test(), but in the meantime, I suspect that you need something like g <- interaction(ano, edadysexo, zona, estacion) fligner.test(rojos ~ g) > > ----- > Mario Garrido Escudero > PhD student > Dpto. de Biología Animal, Ecología, Parasitología, Edafología y Qca. Agrícola > Universidad de Salamanca > -- > View this message in context: > http://r.789695.n4.nabble.com/different-results-from-fligner-test-tp4283312p4283312.html > Sent from the R help mailing list archive at Nabble.com. > > ______________________________________________ > 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. -- Peter Dalgaard, Professor, Center for Statistics, Copenhagen Business School Solbjerg Plads 3, 2000 Frederiksberg, Denmark Phone: (+45)38153501 Email: pd....@cbs.dk Priv: pda...@gmail.com ______________________________________________ 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.
