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Type 'q()' to quit R. > ## use old (<=3.5.2) sample() algorithm if necessary > if ("sample.kind" %in% names(formals(RNGkind))) { + suppressWarnings(RNGkind("Mersenne-Twister", "Inversion", "Rounding")) + } > > > compFunc <- function(lmeMod, lmerMod, tol = 1e-2){ + lmeVarCorr <- nlme:::VarCorr(lmeMod)[,"StdDev"] + lmeCoef <- summary(lmeMod)$tTable[,-c(3,5)] + lmeOut <- c(as.numeric(lmeVarCorr), as.numeric(lmeCoef)) + keep <- !is.na(lmeOut) + lmeOut <- lmeOut[keep] + dn <- dimnames(lmeCoef) + if(is.null(dn)) dn <- list("", names(lmeCoef)) + names(lmeOut) <- c( + paste(names(lmeVarCorr), "Var"), + as.character(do.call(outer, c(dn, list("paste")))))[keep] + + ## get nested RE variances in the same order as nlme + ## FIXME: not sure if this works generally + vcLmer <- VarCorr(lmerMod) + vcLmer <- vcLmer[length(vcLmer):1] + ## + + lmerVarCorr <- c(sapply(vcLmer, attr, "stddev"), + attr(VarCorr(lmerMod), "sc")) + ## differentiate lme4{new} and lme4.0 : + lmerCoef <- if(is(lmerMod, "merMod")) + summary(lmerMod)$coefficients else summary(lmerMod)@coefs + lmerOut <- c(lmerVarCorr, as.numeric(lmerCoef)) + names(lmerOut) <- names(lmeOut) + + return(list(target = lmeOut, current = lmerOut, tolerance = tol)) + } > > if (.Platform$OS.type != "windows") { + set.seed(1) + nGroups <- 100 + nObs <- 1000 + + # explanatory variable with a fixed effect + explVar1 <- rnorm(nObs) + explVar2 <- rnorm(nObs) + + # random intercept among levels of a grouping factor + groupFac <- as.factor(rep(1:nGroups,each=nObs/nGroups)) + randEff0 <- rep(rnorm(nGroups),each=nObs/nGroups) + randEff1 <- rep(rnorm(nGroups),each=nObs/nGroups) + randEff2 <- rep(rnorm(nGroups),each=nObs/nGroups) + + # residuals with heterogeneous variance + residSD <- rpois(nObs,1) + 1 + residError <- rnorm(nObs,sd=residSD) + + # response variable + respVar <- randEff0 + (1+randEff1)*explVar1 + (1+randEff2)*explVar2 + residError + + # rename to fit models on one line + y <- respVar + x <- explVar1 + z <- explVar2 + g <- groupFac + v <- residSD^2 + w <- 1/v + + library("nlme") + lmeMods <- list( + ML1 = lme(y ~ x, random = ~ 1|g, weights = varFixed(~v), method = "ML"), + REML1 = lme(y ~ x, random = ~ 1|g, weights = varFixed(~v), method = "REML"), + ML2 = lme(y ~ x, random = ~ x|g, weights = varFixed(~v), method = "ML"), + REML2 = lme(y ~ x, random = ~ x|g, weights = varFixed(~v), method = "REML"), + ML1 = lme(y ~ x+z, random = ~ x+z|g, weights = varFixed(~v), method = "ML"), + REML2 = lme(y ~ x+z, random = ~ x+z|g, weights = varFixed(~v), method = "REML")) + + library("lme4") + lmerMods <- list( + ML1 = lmer(y ~ x + (1|g), weights = w, REML = FALSE), + REML1 = lmer(y ~ x + (1|g), weights = w, REML = TRUE), + ML2 = lmer(y ~ x + (x|g), weights = w, REML = FALSE), + REML2 = lmer(y ~ x + (x|g), weights = w, REML = TRUE), + ML3 = lmer(y ~ x + z + (x+z|g), weights = w, REML = FALSE), + REML3 = lmer(y ~ x + z + (x+z|g), weights = w, REML = TRUE)) + + comp <- mapply(compFunc, lmeMods, lmerMods, SIMPLIFY=FALSE) + stopifnot(all(sapply(comp, do.call, what = all.equal))) + ## Look at the relative differences: + sapply(mapply(compFunc, lmeMods, lmerMods, SIMPLIFY=FALSE, tol = 0), + do.call, what = all.equal) + + ## add simulated weights to the sleepstudy example + n <- nrow(sleepstudy) + v <- rpois(n,1) + 1 + w <- 1/v + sleepLme <- lme(Reaction ~ Days, random = ~ Days|Subject, + sleepstudy, weights = varFixed(~v), + method = "ML") + sleepLmer <- lmer(Reaction ~ Days + (Days|Subject), + sleepstudy, weights = w, + REML = FALSE) + sleepComp <- compFunc(sleepLme, sleepLmer) + stopifnot(do.call(all.equal, sleepComp)) + ## look at relative differences: + sleepComp$tolerance <- 0 + do.call(all.equal, sleepComp) + + if (require("mlmRev")) { + n <- nrow(Chem97) + v <- rpois(n,1) + 1 + w <- 1/v + Chem97Lme <- lme(score ~ 1, random = ~ 1|lea/school, Chem97) + Chem97Lmer <- lmer(score ~ (1|lea/school), Chem97) + Chem97Comp <- compFunc(Chem97Lme, Chem97Lmer) + stopifnot(do.call(all.equal, Chem97Comp)) + ## look at relative differences: + Chem97Comp$tolerance <- 0 + do.call(all.equal, Chem97Comp) + } + + set.seed(2) + n <- 40 + w <- runif(n) + x <- runif(n) + g <- factor(sample(1:10,n,replace=TRUE)) + Z <- model.matrix(~g-1); + y <- Z%*%rnorm(ncol(Z)) + x + rnorm(n)/w^.5 + m <- lmer(y ~ x + (1|g), weights=w, REML = TRUE) + + ## CRAN-forbidden: + ## has4.0 <- require("lme4.0")) + has4.0 <- FALSE + if(has4.0) { + ## m.0 <- lme4.0::lmer(y ~ x + (1|g), weights=w, REML = TRUE) + lmer0 <- get("lmer", envir=asNamespace("lme4.0")) + m.0 <- lmer0(y ~ x + (1|g), weights=w, REML = TRUE) + dput(fixef(m.0)) # c(-0.73065400610675, 2.02895402562926) + dput(sigma(m.0)) # 1.73614301673377 + dput(VarCorr(m.0)$g[1,1]) # 2.35670451590395 + dput(unname(coef(summary(m.0))[,"Std. Error"])) + ## c(0.95070076853232, 1.37650858268602) + } + fixef_lme4.0 <- c(-0.7306540061, 2.0289540256) + sigma_lme4.0 <- 1.7361430 + Sigma_lme4.0 <- 2.3567045 + SE_lme4.0 <- c(0.95070077, 1.37650858) + if(has4.0) try(detach("package:lme4.0")) + + stopifnot(all.equal(unname(fixef(m)), fixef_lme4.0, tolerance = 1e-3)) + all.equal(unname(fixef(m)), fixef_lme4.0, tolerance = 0) #-> 1.657e-5 + + ## but these are not at all equal : + (all.equal(sigma(m), sigma_lme4.0, tolerance = 10^-3)) # 0.4276 + (all.equal(as.vector(VarCorr(m)$g), Sigma_lme4.0, tolerance = 10^-3)) # 1.038 + (all.equal(as.vector(summary(m)$coefficients[,2]), SE_lme4.0, tolerance = 10^-3)) # 0.4276 + ## so, lme4.0 was clearly wrong here + + + ##' make sure models that differ only in a constant + ##' prior weight have identical deviance: + fm <- lmer(Reaction ~ Days + (Days|Subject), sleepstudy,REML=FALSE) + fm_wt <- lmer(Reaction ~ Days + (Days|Subject), sleepstudy, weights = rep(5, nrow(sleepstudy)),REML=FALSE) + all.equal(deviance(fm), deviance(fm_wt)) + } ## skip on windows (for speed) > > proc.time() user system elapsed 0.15 0.01 0.17