Lets have a sequence of dates,
df = data.frame(date = seq(as.Date('2022-01-01'),as.Date('2022-01-31'),by = 1))
I want to start the week from Tuesday and then cut the dates to create new column week giving the week number. Required output is,
date week
1 2022-01-01 1
2 2022-01-02 1
3 2022-01-03 1
4 2022-01-04 2
5 2022-01-05 2
Similarly, if I wanted to start the week from Wednesday the expected output is,
date week
1 2022-01-01 1
2 2022-01-02 1
3 2022-01-03 1
4 2022-01-04 1
5 2022-01-05 2
6 2022-01-06 2
How can I get this done?
If the week were to start from Monday I would have used,
df%>% mutate(week = cut.Date(df$date, breaks = "1 week", labels = FALSE))
date week
1 2022-01-01 1
2 2022-01-02 1
3 2022-01-03 2
4 2022-01-04 2
5 2022-01-05 2
Thank you for any help…
>Solution :
We may specify the week_start in floor_date (week_start – 1 would be Monday and 7 would be Sunday)
f1 <- function(dates, wk_start = 1) {
new <- lubridate::floor_date(dates, 'week', week_start = wk_start)
match(new, unique(new))
}
-checking
> library(dplyr)
> df %>%
+ mutate(week = f1(date, wk_start = 1)) %>%
+ head
date week
1 2022-01-01 1
2 2022-01-02 1
3 2022-01-03 2
4 2022-01-04 2
5 2022-01-05 2
6 2022-01-06 2
> df %>%
+ mutate(week = f1(date, wk_start = 2)) %>%
+ head
date week
1 2022-01-01 1
2 2022-01-02 1
3 2022-01-03 1
4 2022-01-04 2
5 2022-01-05 2
6 2022-01-06 2
> df %>%
+ mutate(week = f1(date, wk_start = 3)) %>%
+ head
date week
1 2022-01-01 1
2 2022-01-02 1
3 2022-01-03 1
4 2022-01-04 1
5 2022-01-05 2
6 2022-01-06 2