lme4 (version 1.0-5)

confint.merMod: Compute confidence intervals on the parameters of an lme4 fit

Description

Compute confidence intervals on the parameters of a *lmer() model fit (of class"merMod").

Usage

## S3 method for class 'merMod':
confint(object, parm, level = 0.95,
	method = c("profile", "Wald", "boot"), zeta,
	nsim = 500, boot.type = "perc", quiet = FALSE,
	oldNames = TRUE, ...)

Arguments

object
a fitted [ng]lmer model
parm
parameters (specified by integer position)
level
confidence level $< 1$, typically above 0.90.
method
a character string determining the method for computing the confidence intervals.
zeta
(for method = "profile" only:) likelihood cutoff (if not specified, as by default, computed from level).
nsim
number of simulations for parametric bootstrap intervals.
boot.type
bootstrap confidence interval type.
quiet
(logical) suppress messages about computationally intensive profiling?
oldNames
(logical) use old-style names for method="profile"? (See signames argument to profile).
...
additional parameters to be passed to profile.merMod or bootMer, respectively.

Value

  • a numeric table of confidence intervals

Details

Depending on the method specified, confint() computes confidence intervals by [object Object],[object Object],[object Object]

Examples

Run this code
fm1 <- lmer(Reaction ~ Days + (Days|Subject), sleepstudy)
fm1W <- confint(fm1, method="Wald")# very fast, but ....
fm1W
testLevel <- if (nzchar(s <- Sys.getenv("LME4_TEST_LEVEL"))) as.numeric(s) else 1
if(interactive() || testLevel >= 3) {
 ## ~20 seconds, MacBook Pro laptop
 system.time(fm1P <- confint(fm1, method="profile", ## default
                             oldNames = FALSE))
 ## ~ 40 seconds
 system.time(fm1B <- confint(fm1,method="boot",
                             .progress="txt", PBargs=list(style=3)))
} else 
  load(system.file("testdata","confint_ex.rda",package="lme4"))
fm1P
fm1B

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