How to calculate predictions
On Mon, 2012-02-27 at 16:07 -0700, Jake Westfall wrote:
Unless I am misunderstanding what you're after, one thing you can do is just append the fitted values to the data frame (you will want to use math.lme3 at frame in case of dropped observations) and from there pick out the predicted value for each student at age 15. All of the appropriate other effects should be factored in.
I believe that fitted() is giving fitted values for each observation. length(fitted(math.lme3)) [1] 520573 length(unique(math.lme3 at frame$sid)) [1] 236994 I have about 520,000 observations nested within 236,994 students. I want a fitted value for each student at age 15 (which may or may not be actually observed).
Stuart Luppescu -=- slu .at. ccsr.uchicago.edu University of Chicago -=- CCSR ???????? -=- Kernel 3.2.1-gentoo-r2 1st mail: One of the reasons that SAM is popular, is that it is popular (i.e. since everyone has heard of it, it makes reviewers happy). So, it would be nice to be able to point to publications in good journals so that reviewers will be comfortable. (I personally, am quite comfortable with SAM). 2nd mail: Oops, must have been a Freudian slip. Actually, I am not perfectly comfortable with SAM. But I am quite comfortable