R: Fit Linear Mixed-Effects Models

lmer {lmerTest} | R Documentation

## Fit Linear Mixed-Effects Models

### Description

Fit a linear mixed model

### Details

This `lmer` function is an overloaded function of `lmer` (`merMod` class from lme4 package).

### Value

An object of class `"merModLmerTest"`

### See Also

`merModLmerTest` class

### Examples

    library(lmerTest)

    ## linear mixed models
    fm1 <- lmer(Reaction ~ Days + (Days|Subject), sleepstudy)
    fm2 <- lmer(Reaction ~ Days + (1|Subject) + (0+Days|Subject), sleepstudy)

    # anova table the same as of class merMod but with additional F statistics and
    # p-values calculated based on Satterthwaite's approximations
    anova(fm1)

    # anova table the same as of class merMod but with additional F statistics and
    # p-values calculated based on Kenward-Roger's approximations
    ## Not run:
    if(requireNamespace("pbkrtest", quietly = TRUE))
    anova(fm1, ddf="Kenward-Roger")

    # anova table the same as of class merMod
    anova(fm1, ddf="lme4")

    ## End(Not run)

    # gives summary of merModLmerTest class. The same as of class merMod but with
    # additional p-values calculated based on Satterthwate's approximations
    summary(fm1)

    ## multiple comparisons statistics. The one from lme4 package
    ## Not run:
    anova(fm1, fm2)

    ## End(Not run)

[Package lmerTest version 2.0-33 Index]