R - Group by variable and then assign a unique ID [duplicate]

Answer 1

dplyr has a group_indices function for creating unique group IDs

library(dplyr)
data <- data.frame(personal_id = c("111-111-111", "999-999-999", "222-222-222", "111-111-111"),
                       gender = c("M", "F", "M", "M"),
                       temperature = c(99.6, 98.2, 97.8, 95.5))

data$group_id <- data %>% group_indices(personal_id) 
data <- data %>% select(-personal_id)

data
  gender temperature group_id
1      M        99.6        1
2      F        98.2        3
3      M        97.8        2
4      M        95.5        1

Or within the same pipeline (https://github.com/tidyverse/dplyr/issues/2160):

data %>% 
    mutate(group_id = group_indices(., personal_id))