Can you provide the summary(m2) results? > -----Original Message----- > From: Simon Pickett [mailto:[EMAIL PROTECTED] > Sent: Wednesday, August 16, 2006 7:14 AM > To: Doran, Harold > Cc: [email protected] > Subject: [SPAM] - RE: [R] REML with random slopes and random > intercepts giving strange results - Bayesian Filter detected spam > > Hi again, > Even stranger is the fact that the coefficeints (the slope) > and the intercepts are not independent, in fact they are > directly inversely proportional (r squared = 1). > This means that that there isnt a random slope and intercept > for each individual (which is what I wanted), but straight > line that pivots in the middle and will change from > individual to individual. Is there a problem with the way I > have structured the random model or a deeper problem with lmer()? > here is the code I used > m2 <- lmer(changewt ~ newwt+(newwt|id), data = grow) > coef(m2) > Any suggestions very much appreciated, > Simon > > > > I don't this is because you are using REML. The BLUPs from a mixed > > model experience some shrinkage whereas the OLS estimates would not. > > > >> -----Original Message----- > >> From: [EMAIL PROTECTED] > >> [mailto:[EMAIL PROTECTED] On Behalf Of > Simon Pickett > >> Sent: Tuesday, August 15, 2006 11:34 AM > >> To: [email protected] > >> Subject: [R] REML with random slopes and random intercepts giving > >> strange results > >> > >> Hi everyone, > >> I have been using REML to derive intercepts and > coeficients for each > >> individual in a growth study. So the code is > >> m2 <- lmer(change.wt ~ newwt+(newwt|id), data = grow) > >> > >> Calling coef(model.lmer) gives a matrix with this > information which > >> is what I want. However, as a test I looked at each > individual on its > >> own and used a simple linear regression to obtain the same > >> information, then I compared the results. It looks like the REML > >> method doesnt seem to approximate the two parameters as > well as using > >> the simple linear regression on each individual > separately, as judged > >> by looking at graphs. > >> Indeed, why do the results differ at all? > >> Excuse my naivety if this is a silly question. > >> Thanks to everyone for replying to my previous questions, > very much > >> appreciated. > >> Simon Pickett > >> PhD student > >> Centre For Ecology and Conservation > >> Tremough Campus > >> University of Exeter in Cornwall > >> TR109EZ > >> Tel 01326371852 > >> > >> ______________________________________________ > >> [email protected] 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. > >> > > > > > Simon Pickett > PhD student > Centre For Ecology and Conservation > Tremough Campus > University of Exeter in Cornwall > TR109EZ > Tel 01326371852 > >
______________________________________________ [email protected] 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.
