Converts specified level(s) of a factor to NA, removing those levels from
the factor. This differs from the behavior of dplyr::na_if(), which (1)
replaces values with NA but retains the associated factor level, and (2)
can replace only a single value.
Arguments
- x
A factor.
- y
A character vector of levels to convert to NA.
Value
The input factor with specified levels converted to NA and removed from the levels.
Examples
f <- factor(c("a", "b", "c", "a"))
fct_na_if(f, "a")
#> [1] <NA> b c <NA>
#> Levels: b c
fct_na_if(f, c("a", "c"))
#> [1] <NA> b <NA> <NA>
#> Levels: b
# compare `na_if()`
dplyr::na_if(f, "a")
#> [1] <NA> b c <NA>
#> Levels: a b c
