Add additional levels to a factor

Add additional levels to a factor

fct_expand(f, ...)

Arguments

f	A factor (or character vector).
...	Additional levels to add to the factor. Levels that already exist will be silently ignored.

See also

fct_drop() to drop unused factor levels.

Examples

f <- factor(sample(letters[1:3], 20, replace = TRUE))
f
#>  [1] b b a b c b b a c a b c b c c c b c b a
#> Levels: a b c
fct_expand(f, "d", "e", "f")
#>  [1] b b a b c b b a c a b c b c c c b c b a
#> Levels: a b c d e f
fct_expand(f, letters[1:6])
#>  [1] b b a b c b b a c a b c b c c c b c b a
#> Levels: a b c d e f