Cumulative sum until maximum reached, then repeat from zero in the next row

Question

I feel like this is a fairly easy question, but for the life of me I can't seem to find the answer. I have a fairly standard dataframe, and what I am trying to do is sum the a column of values until they reach some value (either that exact value or greater than it), at which point it drops a 1 into a new column (labelled keep) and restarts the summing at 0. I have a column of minutes, the differences between the minutes, a keep column, and a cumulative sum column (the example I am using is much cleaner than the actual full dataset) ``` minutes difference keep difference_sum 1052991158 0 0 0 1052991338 180 0 180 1052991518 180 0 360 1052991698 180 0 540 1052991878 180 0 720 1052992058 180 0 900 1052992238 180 0 1080 1052992418 180 0 1260 1052992598 180 0 1440 1052992778 180 0 1620 1052992958 180 0 1800 ``` The difference sum column was calculated with the code ``` caribou.sub$difference_sum<-cumsum(difference) ``` What I would like to do is run the above code with the condition that, w…

Accepted Answer

I think this is best done with a for loop, can't think of a function that could do so out of the box. The following should do what you want (if I understand you correctly).

```
current.sum <- 0
for (c in 1:nrow(caribou.sub)) {
    current.sum <- current.sum + caribou.sub[c, "difference"]
    carribou.sub[c, "difference_sum"] <- current.sum
    if (current.sum >= 1470) {
        caribou.sub[c, "keep"] <- 1
        current.sum <- 0
    }
}
```

Feel free to comment if it does not exactly what you want. But as pointed out by alexwhan, your description is not completely clear.

Cumulative sum until maximum reached, then repeat from zero in the next row

Solution

Problem