I am trying to find a way to return subject_ids with time_2 that’s earlier than time_1
| subject_id | Time_1 | Time_2 |
|---|---|---|
| 191-5467 | 18:00 | 20:00 |
| 191-6784 | 18:30 | 18:50 |
| 191-3457 | 19:00 | 21:45 |
| 191-0987 | 19:30 | 20:00 |
| 191-1245 | 19:45 | 19:00 |
| 191-2365 | 20:00 | 19:00 |
So in this case the code would return subject id’s 191-1245 and 191-2365 because both their time_2 is earlier than time_1.
>Solution :
A dplyr solution:
library(dplyr)
df %>%
filter(strptime(Time_2, '%H:%M') < strptime(Time_1, '%H:%M')) %>%
pull(subject_id)
[1] "191-1245" "191-2365"