Repeat date twice in a dataframe

January 19, 2022

I would like to make a change to the data frame below. Notice that in date2, I have the sequence of 10 dates, counting from the day 2018-01-01. So far ok, however I would like to have the same date twice, i.e. I would have 2018-01-01 for Category ABC and 2018-01-01 for EFG and so on. How to adjust?

df1 <- data.frame( Id = rep(1:5, length=10),
                   date1 =  as.Date( "2022-01-05"),
                   date2= seq( as.Date("2018-01-01"), length.out=10, by=1),
                   Category = rep(c("ABC", "EFG"), length.out = 10))

   Id      date1      date2 Category
1   1 2022-01-05 2018-01-01      ABC
2   2 2022-01-05 2018-01-02      EFG
3   3 2022-01-05 2018-01-03      ABC
4   4 2022-01-05 2018-01-04      EFG
5   5 2022-01-05 2018-01-05      ABC
6   1 2022-01-05 2018-01-06      EFG
7   2 2022-01-05 2018-01-07      ABC
8   3 2022-01-05 2018-01-08      EFG
9   4 2022-01-05 2018-01-09      ABC
10  5 2022-01-05 2018-01-10      EFG

>Solution :

Use rep(..., each=2) for that.

df1 <- data.frame( Id = rep(1:5, length=10),
                   date1 =  as.Date( "2022-01-05"),
                   date2= rep(seq( as.Date("2018-01-01"), length.out=5, by=1), each = 2),
                   Category = rep(c("ABC", "EFG"), length.out = 10))
df1
#    Id      date1      date2 Category
# 1   1 2022-01-05 2018-01-01      ABC
# 2   2 2022-01-05 2018-01-01      EFG
# 3   3 2022-01-05 2018-01-02      ABC
# 4   4 2022-01-05 2018-01-02      EFG
# 5   5 2022-01-05 2018-01-03      ABC
# 6   1 2022-01-05 2018-01-03      EFG
# 7   2 2022-01-05 2018-01-04      ABC
# 8   3 2022-01-05 2018-01-04      EFG
# 9   4 2022-01-05 2018-01-05      ABC
# 10  5 2022-01-05 2018-01-05      EFG