R- Mutate is not mutating all values

August 5, 2022

I am trying to see if there is a way I can combine lines of code when mutating multiple values based on another value. However, when I use c() as a list, not all values are mutating, only some. Is there something else I need to do, or do I need to have each mutate on an individual line?

Example data:

Category <- c("Additional Fees", "Additional Fees", "None", "None", "Package", "None")
Item <- c("20oz Upgrade", "Ice Cream", "20oz Upgrade", "Ice Cream", "Ice Cream", "20oz Upgrade")
df <- data.frame(Category, Item)

Longer code that works

df2 <- df %>% 
  mutate(Category = ifelse(Item == "20oz Upgrade", "Additional Fees", Category)) %>% 
  mutate(Category = ifelse(Item == "Ice Cream", "Additional Fees", Category))

Combining mutate- but not all values are mutating- I would like to use this though (lines 5 and 6 of Category are not mutating for me).

df1 <- df %>% 
  mutate(Category = ifelse(Item == c("20oz Upgrade", "Ice Cream"), "Additional Fees", Category))

>Solution :

You’ll want to use %in% rather than == because you’re checking if an item is in a vector of two rather than is equal too:

df |> mutate(Category = ifelse(Item %in% c("20oz Upgrade", "Ice Cream"), "Additional Fees", Category))

Output:

         Category         Item
1 Additional Fees 20oz Upgrade
2 Additional Fees    Ice Cream
3 Additional Fees 20oz Upgrade
4 Additional Fees    Ice Cream
5 Additional Fees    Ice Cream
6 Additional Fees 20oz Upgrade