Find 2 out of 3 conditions per ID

August 16, 2022

I have the following dataframe:

df <-read.table(header=TRUE, text="id code
                1 A
                1 B
                1 C
                2 A
                2 A
                2 A
                3 A
                3 B
                3 A")

Per id, I would love to find those individuals that have at least 2 conditions, namely:

conditionA = "A"
conditionB = "B"
conditionC = "C"

and create a new colum with "index", 1 if there are two or more conditions met and 0 otherwise:

df_output <-read.table(header=TRUE, text="id code index
                1 A 1
                1 B 1
                1 C 1
                2 A 0
                2 A 0
                2 A 0
                3 A 1
                3 B 1
                3 A 1")

So far I have tried the following:

df_output = df %>% 
     group_by(id) %>%
     mutate(index = ifelse(grepl(conditionA|conditionB|conditionC, code), 1, 0))

and as you can see I am struggling to get the threshold count into the code. Any help would be more than welcome.

Thanks!

>Solution :

You can create a vector of conditions, and then use %in% and sum to count the number of occurrences in each group. Use + (or ifelse) to convert logical into 1 and 0:

conditions = c("A", "B", "C")

df %>% 
  group_by(id) %>% 
  mutate(index = +(sum(unique(code) %in% conditions) >= 2))

     id code  index
1     1 A         1
2     1 B         1
3     1 C         1
4     2 A         0
5     2 A         0
6     2 A         0
7     3 A         1
8     3 B         1
9     3 A         1