In R, how can I calculate cumsum for a defined time period prior to the row being calculate? Prefer dplyr if possible.
For example, if the period was 10 days, then the function would achieve cum_rolling10:
date value cumsum cum_rolling10
1/01/2000 9 9 9
2/01/2000 1 10 10
5/01/2000 9 19 19
6/01/2000 3 22 22
7/01/2000 4 26 26
8/01/2000 3 29 29
13/01/2000 10 39 29
14/01/2000 9 48 38
18/01/2000 2 50 21
19/01/2000 9 59 30
21/01/2000 8 67 38
25/01/2000 5 72 24
26/01/2000 1 73 25
30/01/2000 6 79 20
31/01/2000 6 85 18