Sequence along numeric vector, increasing sequence only at trigger values [duplicate]-CodePudding

I have a data.frame ordered by ID with a column of numeric values that I would like to bin into groups, increasing the group number only when a certain target value/trigger is surpassed. I haven't had success with seq(), seq_along(), or data.table cumsum(), but I'm sure there must be a way

Example data.frame with desired group column below. In this example, the sequence generating the group column should increase only when a number >= 300 appears in the value column.

dat = data.frame(ID=1:10, value=c(0,2,1,12,68,300,41,0,72959,51), group=c(1,1,1,1,1,2,2,2,3,3))

> dat
   ID value group
1   1     0     1
2   2     2     1
3   3     1     1
4   4    12     1
5   5    68     1
6   6   300     2
7   7    41     2
8   8     0     2
9   9 72959     3
10 10    51     3

CodePudding user response：

We may use cumsum on a logical vector to create the group

library(dplyr)
dat %>%
     mutate(group2 = cumsum(value >=300)  1)

-output

   ID value group group2
1   1     0     1      1
2   2     2     1      1
3   3     1     1      1
4   4    12     1      1
5   5    68     1      1
6   6   300     2      2
7   7    41     2      2
8   8     0     2      2
9   9 72959     3      3
10 10    51     3      3