I have:
| id | num |
|---|---|
| 1 | 5 |
| 2 | 2 |
| 3 | 10 |
| 4 | 20 |
| 5 | 3 |
and I want to get:
| id | num |
|---|---|
| 1 | 40 |
| 2 | 35 |
| 3 | 33 |
| 4 | 23 |
| 5 | 3 |
so: 1 or more, 2 or more ...
3 Answers
In base R you could do this: The logic was first implemented by akrun:
df[, 2] <- rev(cumsum(rev(df[, 2])))
Output:
id num
1 1 40
2 2 35
3 3 33
4 4 23
5 5 3
Or another option would be:
library(purrr)
df1 %>%
mutate(num = accumulate(num, `+`, .dir = "backward"))
id num
1 1 40
2 2 35
3 3 33
4 4 23
5 5 3
We can do
library(dplyr)
df1 %>%
mutate(num = rev(cumsum(rev(num))))
-ouptut
id num
1 1 40
2 2 35
3 3 33
4 4 23
5 5 3
Or use
library(spatstat.utils)
df1 %>%
mutate(num = revcumsum(num))
id num
1 1 40
2 2 35
3 3 33
4 4 23
5 5 3
data
df1 <- structure(list(id = 1:5, num = c(5L, 2L, 10L, 20L, 3L)),
class = "data.frame", row.names = c(NA,
-5L))
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