tests/falsezero_dorie.R

if (.Platform$OS.type != "windows") {
    ## test of false zero problem reported by Vince Dorie
    ## (no longer occurs with current development lme4)
    ## https://github.com/lme4/lme4/issues/17
    library(lme4)

    sigma.eps <- 2
    sigma.the <- 0.75
    mu <- 2

    n <- 5
    J <- 10
    g <- gl(J, n)

    set.seed(1)

    theta <- rnorm(J, 0, sigma.eps * sigma.the)
    y <- rnorm(n * J, mu + theta[g], sigma.eps)
    lmerFit <- lmer(y ~ 1 + (1 | g), REML = FALSE, verbose=TRUE)

    y.bar <- mean(y)
    y.bar.j <- sapply(1:J, function(j) mean(y[g == j]))
    S.w <- sum((y - y.bar.j[g])^2)
    S.b <- n * sum((y.bar.j - y.bar)^2)
    R <- S.b / S.w

    sigma.the.hat <- sqrt(max((n - 1) * R / n - 1 / n, 0))
    stopifnot(all.equal(sigma.the.hat,lme4Sigma <- unname(getME(lmerFit,"theta")),
                        tolerance=2e-5))
} ## skip on windows (for speed)

Try the lme4 package in your browser

Any scripts or data that you put into this service are public.

lme4 documentation built on June 22, 2021, 9:07 a.m.