Replace in a factor column

Question

I want to replace values in a factors column with a valid value. But I can not find a way. This example is only for demonstration. The original data

Answer 1

I had similar issues and I want to add what I consider the most pragmatic (and also tidy) solution:

Convert the column to a character column, use mutate and a simple ifelse-statement to change the NA values to what you want the factor level to be (I have chosen "None"), convert it back to a factor column:

df %>% mutate(
a = as.character(a),
a = ifelse(is.na(a), "None", a),
a = as.factor(a)
)

Clean and painless because you do not actually have to dabble with NA values when they occur in a factor column. You bypass the weirdness and end up with a clean factor variable.