Create a compact edge-panel generator for tree plots — tree_edge_panel

Builds a partykit graph-content generator that draws compact edge labels using tree_compact_split_label(). This is useful when factor splits have many levels or when tree plots need shorter, more readable split labels.

Usage

tree_edge_panel_compact(
  obj,
  var_labels = NULL,
  digits = 3,
  fill = "white",
  justmin = 4,
  just = c("alternate", "increasing", "decreasing", "equal"),
  max_items = 3L,
  max_chars = 24L,
  plural_overrides = NULL
)

Arguments

obj: A fitted tree object inheriting from party.
var_labels: An optional named character vector of display labels.
digits: Number of digits to use when formatting numeric split labels.
fill: Fill color used behind edge labels.
justmin: Minimum average label width before alternating justification is used.
just: One of "alternate", "increasing", "decreasing", or "equal" controlling vertical placement of sibling edge labels.
max_items: Maximum number of comma-separated items to show before shortening the label.
max_chars: Maximum wrapping width used for unshortened labels.
plural_overrides: An optional named character vector giving custom plural nouns for summarized level groups.

Value

A graph-content generator function suitable for the edge_panel argument of partykit::plot.party().

Examples

data(kenya, package = "ineqTrees")
kenya_plot_vars <- c("wealth", "deadu5_num", "rural", "ed", "reg", "unskilled")
kenya_plot_data <- kenya[
  stats::complete.cases(kenya[, kenya_plot_vars]),
  kenya_plot_vars
]
set.seed(20260512)
kenya_plot_data <- kenya_plot_data[
  sample.int(nrow(kenya_plot_data), 800L),
  ,
  drop = FALSE
]
kenya_plot_fit <- ci_tree(
  cbind(wealth, deadu5_num) ~ rural + ed + reg + unskilled,
  data = kenya_plot_data,
  rank_name = "wealth",
  outcome_name = "deadu5_num",
  control = ci_tree_control(
    minsplit = 100,
    minbucket = 50,
    minprob = 0.05,
    maxdepth = 3
  )
)
kenya_var_labels <- c(
  rural = "Residence",
  ed = "Mother education",
  reg = "Province",
  unskilled = "Mother occupation"
)

inherits(tree_edge_panel_compact, "grapcon_generator")
#> [1] TRUE
is.function(tree_edge_panel_compact(
  kenya_plot_fit,
  var_labels = kenya_var_labels,
  plural_overrides = c(Province = "provinces")
))
#> [1] TRUE