forcats 🐈🐈🐈🐈

forcats provides tools for categorical variables (forcats is an anagram of factors).

Installation

You can install forcthe released version of forcats from CRAN with:

install.packages("forcats")

Or the development versionm github with:

# install.packages("devtools")
devtools::install_github("hadley/forcats")

Key functions:

Change order of levels:

• fct_relevel(): move specified level up front.

• fct_inorder(): order by first appearance of each level.

• fct_reorder(): order by summary of another value (same as stats::reorder()).

• fct_infreq():
  order by frequency.

• fct_shuffle(): randomly shuffle order of levels.

• fct_rev(): reverse order of levels.

• fct_shift(): shift levels to the left/right.

Change value of levels:

• fct_anon(): anonymise factor levels.

• fct_lump(): lump rarest (or most common) levels into "other".

• fct_recode(): manually recode levels.

Add new levels:

• fct_expand(): add new levels to a factor.

• fct_explicit_na(): turn missing values into an explicit factor.

A few other helpers:

• fct_c(): concatenate factors using union of levels.

• fct_count():
  count occurences of levels, optionally sorting by frequency.

• fct_unify():
  ensure list of factors share the same levels.

• fct_unique(): compute from levels of factor.

• fct_drop(): drop levels without data (same as base::droplevels()).

• lvls_union(): finds union of levels from list of factors.