Extract factor levels from a data frameSource:
get_levels() extracts the levels from any factor columns in
data. It is
mainly useful for extracting the original factor levels from the predictors
in the training set.
get_outcome_levels() is a small wrapper around
get_levels() for extracting levels from a factor outcome
that first calls
A data.frame to extract levels from.
The outcome. This can be:
A factor vector
A numeric vector
A 1D numeric array
A numeric matrix with column names
A 2D numeric array with column names
A data frame with numeric or factor columns
A named list with as many elements as there are factor columns in
y. The names are the names of the factor columns, and the values
are character vectors of the levels.
If there are no factor columns,
NULL is returned.
# Factor columns are returned with their levels get_levels(iris) #> $Species #>  "setosa" "versicolor" "virginica" #> # No factor columns get_levels(mtcars) #> NULL # standardize() is first run on `y` # which converts the input to a data frame # with an automatically named column, `".outcome"` get_outcome_levels(y = factor(letters[1:5])) #> $.outcome #>  "a" "b" "c" "d" "e" #>