I'm manually doing a form of stepwise regression in a mixed model but with many variables, it is time consuming. I thought I'd try to use an automated approach. stepAIC gave me false convergence when I used it with my model, so I thought it can't be hard to set up a basic program to do it based on the p-values. Thus I tried a couple of (very) crude options:
1) trying to 'multiply' my 40 terms by a vector of length 40 of 1's (some of which would then become 0's so that the term would be effectively eliminated in the model). This didn't work as lme didn't recognise the vector. 2) setting the term I wished to drop to a column of 0's so it couldn't be used in the analysis, but this created a singularity which then stopped lme from working.... Hmm, perhaps I should abandon such abominations ... does anyone have some advice on how I might get such a crude method working or must I turn back and fight with stepAIC? Thank you! -- View this message in context: http://r.789695.n4.nabble.com/Stepwise-in-lme-tp4224724p4224724.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.