dplyr mutate问题案例

Question

I have the following data:

d <- data.frame(
        ID= c("NULL", "NULL", "1232", "4565", "4321"))

I'm trying to create a new line that shows "missing" when the ID is NULL, and "not missing" when the ID is not NULL. I have the following code:

d %>%
mutate(ID_missing= case_when(ID=="NULL") ~ "missing", 
                           ID!="NULL" ~ "not missing", TRUE ~ NA_real_) -> d

however I get the following error:

Error in mutate_impl(.data, dots) : 
Column `name_of` is of unsupported type quoted call

I can't see any guidance on line and I can't see what might be wrong with my code. Any ideas?

Answer 1

There are two problems in your approach:

1) parenthesis

Your use of case_when is incorrect because of the closing parenthesis in the middle of the function. It should be

case_when(ID=="NULL" ~ "missing", 
          ID!="NULL" ~ "not missing", 
          TRUE       ~ NA_real_))

2) Incorrect NA-type

You're using NA_real_ inside a character column. You need to use NA_character_ instead.

The final would then be:

d %>%
    mutate(ID_missing= case_when(ID=="NULL" ~ "missing", 
           ID!="NULL" ~ "not missing", TRUE ~ NA_character_)) -> d

#     ID  ID_missing
# 1 NULL     missing
# 2 NULL     missing
# 3 1232 not missing
# 4 4565 not missing
# 5 4321 not missing

Answer 2

Below would work .

require(dplyr)
d <- data.frame(
ID= c("NULL", "NULL", "1232", "4565", "4321"))

#### USE mutate and ifelse 

d <- d %>% mutate(ID_missing = ifelse(ID == "NULL","missing","not_missing"))