Doug Bates is the authority of course, but perhaps a couple of quick inline comments may suffice:
-----Original Message----- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Mitchell Maltenfort Sent: Wednesday, October 22, 2008 7:41 AM To: r-help@r-project.org Subject: [R] Think I'm sure, but confirm: lme4 vs. nlme The impression I get from the list and the references I've perused is that nlme is being phased out in favor of lme4, but lme4 still doesn't have a complete feature set yet. -- Not exactly. nlme isn't really being phased out (yet anyway) -- it's just not being improved anymore. However, it is a pretty nice implementation of mixed effects models for continuous data with Gaussian errors with nested random effects. And not too large data sets. I would opine that it handles the bulk of mixed effects models that one encounters in the physical and biological sciences very well. What I'm still fuzzy on, being a relative R newbie, is: (a) what features in nlme are currently missing in lme4 (b) what's the projected time frame on getting them implemented. -- I think the time frame is "continuing, as Doug is able to work on it." As a user, I would say that this is not a discrete event, but an evolving work. I use lme4 routinely now. As for features, that is difficult to answer. Last I checked, nlme has a good predict method but lme4 didn't. lme4 does mcmc for the posterior distribution of parameters in Gaussian models, nlme doesn't; but nlme does an approximate version of confidence intervals for parameters. Also lme4 handles glm's, crossed random factors, very large data sets; nlme does none of this. Etc. Doug may, of course, have corrections or additions here. If anyone can answer my naive and impertinent question in a friendly, helpful and informative manner[1], I would be delighted. Thanks! -- I didn't consider your questions naive or impertiment. I leave it to you to judge whether I have been friendly or helpful. Cheers, Bert Gunter [1] Or, translated from craven, "please don't ignite a flame war on my no-account account" Regards, Mitch -- Due to the recession, requests for instant gratification will be deferred until arrears in scheduled gratification have been satisfied. ______________________________________________ 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. ______________________________________________ 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.
