Create a factor with case_when logic and automatic level ordering

This function combines the functionality of dplyr::case_when() with automatic factor level ordering. It creates a factor where the levels are ordered according to the sequence they appear in the case_when conditions.

fct_case_when(..., dir = 1)

Arguments

...

A series of two-sided formulas. The left hand side (LHS) determines which values match this case. The right hand side (RHS) provides the value to use for the output.

dir

Direction of factor levels. Use 1 for the same order as input (default), or -1 to reverse the order.

Value

A factor with levels ordered according to their appearance in the case_when conditions, and the specified direction.

Note

This function was adapted from an answer provided to StackOverflow post #69333730 (https://stackoverflow.com/a/69333730)

Examples

library(dplyr)
#> 
#> Attaching package: 'dplyr'
#> The following objects are masked from 'package:stats':
#> 
#>     filter, lag
#> The following objects are masked from 'package:base':
#> 
#>     intersect, setdiff, setequal, union
library(tibble)

# Create a sample dataset of cost burden percent values
set.seed(123)
cost_burden <- tibble(
  pct = runif(100, min = 0, max = 1)
)

# Apply fct_case_when to create labels
cost_burden_label <- cost_burden |>
  mutate(
    cb = fct_case_when(
      pct < 0.30 ~ "Not cost-burdened",
      pct < 0.50 ~ "Cost-burdened",
      pct >= 0.50 ~ "Severely cost-burdened"
    )
  )

# Check the levels of the new factor column
levels(cost_burden_label$cb)
#> [1] "Not cost-burdened"      "Cost-burdened"          "Severely cost-burdened"