根据与上一行的差异对行进行分组

I have a data.frame with difftimes created with hms::hms on it. I know I can use arrange() and diff() to check the time elapsed between each observation.

我有一个带有hms :: hms创建的difftimes的data.frame。我知道我可以使用arrange()和diff()来检查每次观察之间经过的时间。

How can I create a $session variable that changes its value when the time elapsed is bigger than a predefined value?

如何在经过的时间大于预定义值时创建一个更改其值的$ session变量?

For example, given the data below:

例如,给出以下数据:

    hour         time_elapsed
15:58:05                   NA
15:58:11                    6
15:58:17                    6
15:58:44                   27
15:58:51                    7
15:58:57                    6

Considering values bigger than 25 as the breaking point, we would have:

考虑大于25的值作为突破点,我们将:

    hour         time_elapsed     session
15:58:05                   NA           1
15:58:11                    6           1
15:58:17                    6           1
15:58:44                   27           2
15:58:51                    7           2
15:58:57                    6           2

Thanks in advance!

提前致谢!

1 个解决方案

#1

We can replace the NA with 0, then create a logical condition and do the cumulative sum

我们可以用0替换NA,然后创建逻辑条件并进行累积求和

df1$session <- with(df1, cumsum(replace(time_elapsed, is.na(time_elapsed), 0) >25) + 1)