Post on the r-sig-mixed-models list, not here.* -- Bert * Or consult a local statistician, as your problem appears to be insufficient statistical knowledge, rather than R-related. In particular, fitting a (mixed effect) linear model without an intercept is almost always unwise.
On Thu, Jul 12, 2012 at 12:37 AM, Julien Leblud <julien.leb...@umons.ac.be>wrote: > Dear list, > > I'm quite confused when interpreting results from a mixed linear model. > > For example, working on Iris data frame, I want to know the effect of > species on slope of the model "Petal.Length~Sepal.Length" > > I write this : > > data(iris) > reg01 <- lm(Petal.Length~Sepal.Length + Sepal.Length:Species, data=iris) > summary(reg01) > > It gives me a summary table with lm for the first factor, i.e setosa, and > the effects of each levels of Species on interactions, which mean on the > slope. > > Now, i would like a model with intercept =0. I should write this: > > data(iris) > reg02 <- lm(Petal.Length~Sepal.Length + Sepal.Length:Species - 1 , > data=iris) > summary(reg02) > > ...But results is meaningless for me... > > Any idea to fit a model like this? > Thanks a lot ! > > Julien > > -- > *********************************************** > Julien Leblud > > Numerical Ecology of Aquatic Systems > Mons University, Belgium > > http://econum.umons.ac.be/**labo/ <http://econum.umons.ac.be/labo/> > > ..............................**<°}))><........ > > Ecologie Numérique des Milieux Aquatiques > Université de Mons > > tel. +32 (0) 65 37 36 65 > > Pentagone (aile 3D) > 6, Avenue du Champ de Mars > 7000 Mons, Belgium > > ______________________________**________________ > R-help@r-project.org mailing list > 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-guide.html <http://www.R-project.org/posting-guide.html> > and provide commented, minimal, self-contained, reproducible code. > -- Bert Gunter Genentech Nonclinical Biostatistics Internal Contact Info: Phone: 467-7374 Website: http://pharmadevelopment.roche.com/index/pdb/pdb-functional-groups/pdb-biostatistics/pdb-ncb-home.htm [[alternative HTML version deleted]]
______________________________________________ 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.
