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> ## simple examples with offsets, to exercise methods etc.
> 
> library(lme4)
Loading required package: Matrix
> 
> if (.Platform$OS.type != "windows") {
+ ## generate a basic Gamma/random effects sim
+ set.seed(101)
+ d <- expand.grid(block=LETTERS[1:26],rep=1:100)
+ d$x <- runif(nrow(d))  ## sd=1
+ reff_f <- rnorm(length(levels(d$block)),sd=1)
+ ## need intercept large enough to avoid negative values
+ d$eta0 <- 4+3*d$x  ## version without random effects
+ d$eta <- d$eta0+reff_f[d$block]
+ 
+ ## lmer() test:
+ d$mu <- d$eta
+ d$y <- rnorm(nrow(d),mean=d$mu,sd=1)
+ 
+ fm1    <- lmer(y~x+(1|block),            data=d)
+ fm1off <- lmer(y~x+(1|block)+offset(3*x),data=d)
+ 
+ ## check equality
+ stopifnot(all.equal(fixef(fm1)[2]-3,fixef(fm1off)[2]))
+ 
+ p0 <- predict(fm1)
+ p1 <- predict(fm1,newdata=d)
+ p2 <- predict(fm1off,newdata=d)
+ stopifnot(all.equal(p0,p1),
+           all.equal(p1,p2))
+ 
+ 
+ ## glmer() test:
+ d$mu <- exp(d$eta)
+ d$y <- rpois(nrow(d),d$mu)
+ 
+ gm1    <- glmer(y~x+(1|block),            data=d,family=poisson,
+                 control=glmerControl(check.conv.grad="ignore"))
+ gm1off <- glmer(y~x+(1|block)+offset(3*x),data=d,family=poisson,
+                 control=glmerControl(check.conv.grad="ignore"))
+ 
+ ## check equality
+ stopifnot(all.equal(fixef(gm1)[2]-3,fixef(gm1off)[2],tolerance=3e-4))
+ 
+ p0 <- predict(gm1)
+ p1 <- predict(gm1,newdata=d)
+ p2 <- predict(gm1off,newdata=d)
+ stopifnot(all.equal(p0,p1),
+           all.equal(p1,p2))
+ 
+ ## FIXME: should also test simulations
+ } ## skip on windows (for speed)
> 
> proc.time()
   user  system elapsed 
   1.64    0.18    1.82