insert rows between dates by group

Question

I want to insert rows between two dates by group. My way of doing it is so complicated that I insert missing values by last observation carry forwards and then merge. I was wond

Answer 1

By using dplyr and tidyr :)(one line solution )

library(dplyr)
library(tidyr)
dt %>% group_by(user) %>% complete(date=full_seq(date,1),fill=list(dummy=0))
# A tibble: 9 x 3
# Groups:   user [2]
    user       date dummy
        
1      A 2017-01-03     1
2      A 2017-01-04     0
3      A 2017-01-05     0
4      A 2017-01-06     1
5      B 2016-05-01     1
6      B 2016-05-02     0
7      B 2016-05-03     1
8      B 2016-05-04     0
9      B 2016-05-05     1