Speed estimation for lmer?
On Thu, Sep 11, 2008 at 4:56 PM, Daniel Ezra Johnson
<danielezrajohnson at gmail.com> wrote:
so if my response is on a continuous scale, is there any difference between lmer(y~fixed+(1|random)) and glmer(y~fixed+(1|random),family="gaussian") ? the output is the same but since reading the above i'm wondering if 'plain' lmer is written to run faster?
Those calls will be equivalent but if you look closely at the object
produced by the glmer call you will find that it has been quietly
replaced by a call to lmer. There is a section in glmer that reads
if(family$family == "gaussian" && family$link == "identity") {
mc[[1]] <- as.name("lmer") # use lmer not glmer
mc$family <- NULL
return(eval.parent(mc))
}
This must be a close cousin of the code that turns e.g. d <- lmer(y~fixed(1|random),twelve,family="binomial") into a call to glmer!
Yes. At times I have thought that having a separate glmer function made sense and at other times I have thought that having lmer handle linear or generalized linear or nonlinear or generalized nonlinear mixed models would be the best way to go. I still don't know and would prefer not to antagonize all those people who have written papers and even books mentioning glmer and lmer by removing the glmer function. In time it is possible that glmer will become a stub, just as lmer2 is now.