Bert and anyone else with info, First, Bert thank you for your quick reply. drop1 gives the results as a type II anova. Is there a way to make drop1 give you type I anova (the args don't appear to have a way to do so)? Another package/function perhaps? Tyler > Date: Thu, 31 Mar 2011 09:32:02 -0700 > Subject: Re: [R] Sequential multiple regression > From: gunter.ber...@gene.com > To: tyler_rin...@hotmail.com > CC: r-help@r-project.org > > ?drop1 > > -- Bert > > On Thu, Mar 31, 2011 at 9:24 AM, Tyler Rinker <tyler_rin...@hotmail.com> > wrote: > > > > Hello, > > > > In the past I have tended to reside more in the ANOVA camp but am trying to > > become more familiar with regression techniques in R. I would like to get > > the F change from a model as I take away factors: > > > > SO... > > > > mod1<-lm(y~x1+x2+x3).......mod2<-lm(y~x1,x2).......mod3<-lm(y~x1) > > > > > > I can do this by hand by running several models in R and taking the > > MSr1/MSe1, MSr2/MSe2... This is slow and I know there's a better way. > > > > In SPSS (which I no longer use) I could easily obtain these results > > (F-change) as documented by Professor Andy Fields: > > http://www.statisticshell.com/multireg.pdf > > > > You can see the F changes for his two IV model yielding 2 F changes. Maybe > > it's the language I'm using (sequential multiple regression) that yields me > > poor results in searching the archives and Rseek. The results tend to be > > around hierarchal regression (I'm not familiar with this terminology being > > in the ANOVA camp). When I look at the hier.part package and run the > > examples it doesn't seem to give me the F change I'm looking for. The step > > function in the base program reduces the model but takes away the non sig. > > IV's (which is a great approach but I'm really after those F changes). As > > is the usually the case I'm sure R does this simply and beautifully, I'm > > just not experienced with the statistical vocabulary and techniques around > > regression to find what I'm looking for. > > > > F-change values with R: Any help would be appreciated. > > > > Thank you in advance, > > Tyler > > [[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. > > > > > > -- > "Men by nature long to get on to the ultimate truths, and will often > be impatient with elementary studies or fight shy of them. If it were > possible to reach the ultimate truths without the elementary studies > usually prefixed to them, these would not be preparatory studies but > superfluous diversions." > > -- Maimonides (1135-1204) > > Bert Gunter > Genentech Nonclinical Biostatistics [[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.
