R version 4.4.0 beta (2024-04-14 r86421 ucrt) -- "Puppy Cup" Copyright (C) 2024 The R Foundation for Statistical Computing Platform: x86_64-w64-mingw32/x64 R is free software and comes with ABSOLUTELY NO WARRANTY. You are welcome to redistribute it under certain conditions. Type 'license()' or 'licence()' for distribution details. R is a collaborative project with many contributors. Type 'contributors()' for more information and 'citation()' on how to cite R or R packages in publications. Type 'demo()' for some demos, 'help()' for on-line help, or 'help.start()' for an HTML browser interface to help. Type 'q()' to quit 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) > > proc.time() user system elapsed 0.10 0.04 0.14