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Caterpillar plot of random effects

Source: R/random_effects_plot.R
random_effects_plot.Rd

Displays the conditional modes ("BLUPs") of a mixed model's random effects as a sorted point-and-interval ("caterpillar") plot. It is the usual way to inspect by-group departures from the average, and to identify unusual groups.

Usage

random_effects_plot(
  x,
  conf_level = 0.95,
  sort = TRUE,
  point_colour = depictr_brand(),
  title = NULL,
  x_lab = "Random effect"
)

Arguments

x

Either a mixed model fitted with 'lme4' (merMod), or a data frame with one row per group level and columns such as level/group, estimate, and either conf.low/conf.high or std.error. An optional term column facets the plot.

conf_level

Confidence level when intervals are derived from standard errors.

sort

Whether to order the levels by their estimate.

point_colour

Colour for the points and intervals.

title, x_lab

Plot title and value-axis label.

Value

A ggplot2::ggplot object.

Examples

# From a data frame of by-group estimates:
re <- data.frame(
  level = paste0("G", 1:10),
  estimate = sort(rnorm(10)),
  std.error = runif(10, 0.2, 0.5)
)
random_effects_plot(re)


# \donttest{
if (requireNamespace("lme4", quietly = TRUE)) {
  m <- lme4::lmer(RT ~ condition + (1 | participant), data = lexical_decision)
  random_effects_plot(m)
}

# }