Helper Function for Collapsing of Factor Levels — h_collapse

Given a group list and a factor, this helper function collapses the levels in the factor accordingly and also ensures that the resulting levels are in the order given in the group list.

Usage

h_collapse_levels(x, group_list)

Arguments

x: (factor)
original factor.
group_list: (named list of character)
includes the collapsing specification.

Value

The transformed factor x with new levels.

Examples

set.seed(123)
x <- factor(sample(
  c("ASIAN", "BLACK OR AFRICAN AMERICAN", "MULTIPLE", "UNKNOWN", "WHITE"),
  size = 30L,
  replace = TRUE
))
group_list <- list(
  "ASIAN/BLACK OR AFRICAN AMERICAN" = c("ASIAN", "BLACK OR AFRICAN AMERICAN"),
  "MULTIPLE/UNKNOWN" = c("MULTIPLE", "UNKNOWN"),
  "WHITE" = "WHITE"
)
x_collapsed <- h_collapse_levels(x, group_list)
stopifnot(identical(levels(x_collapsed), names(group_list)))