如何删除R数据帧中事件的连续出现？

Question

I have a R dataframe containing date info about generic events: id;start_date;end_date.

Sometimes the same event may occur the same day (1) or at a distance of one day (2), for example:

(1) 1001;2016-05-07;2016-05-11 1001;2016-05-11;2016-05-14

(2) 1001;2016-05-07;2016-05-11 1001;2016-05-12;2016-05-14

In the first case the event "1001" ends and restarts the same day, while in the second case that event ends on 2017-05-11 and starts again the day after. I'd like to delete the second occurrence of the event in both cases. If the second occurrence is at a distance of two or more days, it's ok to preserve the second occurrence. How can I do this in R?

Thank you in advance.

Answer 1

Partial solution with my guess of how data look like:

library(data.table)
dat <- data.table(id = c(1001,1001,1001,1001),
                  start_date = as.Date(c("2016-05-07", "2016-05-11", "2016-05-07", "2016-05-12")),
                  end_date = as.Date(c("2016-05-11", "2016-05-14", "2016-05-11", "2016-05-14")))

dat2 <- data.table(id = c(dat$id, NA),
                   start_date = c(dat$start_date, NA),
                   end_date = c(as.Date(NA), dat$end_date))

dat2[, dif := end_date - start_date]

Then you can just remove rows with dif <= 0 I guess.

I've used the data.table package, but you can just do dat2$dif <- dat2$end_date - dat2$start_date .