forcats

In R, factors are used to handle categorical variables (variables with a fixed, known set of possible values). The forcats package provides tools to solve common problems with factors, such as changing the order of levels or the values themselves.

Key capabilities include:

• Reordering by another variable: Use fct_reorder().
• Reordering by frequency: Use fct_infreq().
• Manual reordering: Use fct_relevel() to change the order of levels by hand.
• Collapsing levels: Use fct_lump() to collapse the least or most frequent values into an "other" category.

To use forcats, load it using library(forcats) or as part of the tidyverse using library(tidyverse).

Common workflows involve using forcats functions within dplyr::mutate() to transform factor columns before plotting with ggplot2 or performing counts.

library(forcats)
library(dplyr)
library(ggplot2)

# Example: Collapsing infrequent species into 'Other'
starwars |> 
  filter(!is.na(species)) |> 
  mutate(species = fct_lump(species, n = 3)) |> 
  count(species)

# Example: Reordering eye color by frequency for a plot
starwars |> 
  mutate(eye_color = fct_infreq(eye_color)) |> 
  ggplot(aes(x = eye_color)) + 
  geom_bar() + 
  coord_flip()

You can install forcats via CRAN or the development version from GitHub.

To install the entire tidyverse suite:

install.packages("tidyverse")

To install only forcats:

install.packages("forcats")

To install the development version from GitHub using pak:

# install.packages("pak")
pak::pak("tidyverse/forcats")