Cumulative count of each value
count, cumulative-sum, r, running-count
Solution
The `dplyr` way:
library(dplyr)
foo <- data.frame(id=c(1, 2, 3, 2, 2, 1, 2, 3))
foo <- foo %>% group_by(id) %>% mutate(count=row_number())
foo
# A tibble: 8 x 2
# Groups: id [3]
id count
<dbl> <int>
1 1 1
2 2 1
3 3 1
4 2 2
5 2 3
6 1 2
7 2 4
8 3 2
That ends up grouped by `id`. If you want it not grouped, add `%>% ungroup()`.
Problem
I want to create a cumulative counter of the number of times each value appears. e.g. say I have the column: ``` id 1 2 3 2 2 1 2 3 ``` This would become: ``` id count 1 1 2 1 3 1 2 2 2 3 1 2 2 4 3 2 ``` etc...