This is probably simple, but I'm missing it. In the example I have several id's with multiple values each. Within each id, I want to be able to set x to equal 0 only after the occurrence of a 2, leaving the other values untouched.
Is there a dplyr way to do this?
test <- structure(list(id = c(1, 1, 1, 1, 1, 2, 2, 2, 2, 2, 3, 3, 3,
3, 3, 4, 4, 4, 5, 5, 5, 5, 5, 6, 6, 6, 6, 6, 7, 7, 7, 8, 8, 8,
8, 8, 9, 9, 9, 9, 9, 10, 10, 10, 10, 10), x = c(0L, 1L, 1L,
2L, 1L, 0L, 0L, 1L, 2L, 1L, 0L, 0L, 1L, 2L, 1L, 0L, 0L, 0L, 0L,
1L, 1L, 2L, 1L, 0L, 0L, 2L, 1L, 1L, 0L, 0L, 0L, 0L, 0L, 1L, 2L,
1L, 0L, 0L, 2L, 1L, 1L, 0L, 1L, 2L, 1L, 1L)), row.names = c(NA,
-46L), class = "data.frame")
> head(test, 10)
id x
1 1 0
2 1 1
3 1 1
4 1 2
5 1 1
6 2 0
7 2 0
8 2 1
9 2 2
10 2 1
mutate(test, x_new=ifelse(+cumsum(lag(x, default=0)==2), 0, x), .by=id)
id x x_new
1 1 0 0
2 1 1 1
3 1 1 1
4 1 2 2
5 1 1 0
6 2 0 0
7 2 0 0
8 2 1 1
9 2 2 2
10 2 1 0
11 3 0 0
12 3 0 0
13 3 1 1
14 3 2 2
15 3 1 0