Is there a better way to write this if-else statement?

Question

I am wondering if there is an easier way to create these variables than what I am doing? I am trying to turn the values of my vehicle type variable in to variables themselves.

Answer 1

There is a helper function in the cobalt package for this called splitfactor(), which splits factors into dummy variables. You would run the following:

norm.knnN <- cobalt::splitfactor(norm.knnN, 
                                c("gearbox", "vehicleType", 
                                 "fuelType", "brand", "notRepairedDamage"), 
                                drop.first = "if2")

Setting drop.first = "if2" makes it so that if a factor has two values (e.g., "yes" and "no"), one of the dummy variables will be dropped since it is perfectly redundant to the other one.

Answer 2

It is better to use dplyr's syntax. There are some literature to learn how to use the syntax. (https://genomicsclass.github.io/book/pages/dplyr_tutorial.html)

In the syntax, I usually use case_when function to make several condition rather than ifelse function.

norm.knnN$gearbox[norm.knnN$gearbox=="automatic"] = 1
norm.knnN$gearbox[norm.knnN$gearbox=="manual"] = 0

It would be changed to this syntax I mentioned.

 norm.knnN %>%
    mutate(gearbox = case_when(
    gearbox == "automatic" ~ 1,
    gearbox == "manual" ~ 0,
    TRUE ~ NA))