Running sums for every row of the previous 25 rows

Question

I've been trying for a while now to produce a code that brings me a new vector of the sum of the 25 previous rows for an original vector. So if we say I have a variable Y with 500 rows and I would like a running sum, in a new vector, which contains the sum of rows [1:25] then [2:26] for the length of Y, such as this: ``` y<-1:500 runsum<-function(x){ cumsum(x)-cumsum(x[26:length(x)]) } new<-runsum(y) ``` I've tried using some different functions here and then even using the apply functions on top but none seem to produce the right answers.... Would anyone be able to help? I realise it's probably very easy for many of the community here but any help would be appreciated Thanks

Accepted Answer

This function calculates the sum of the 24 preceding values and the actual value:

```
 movsum <- function(x,n=25){filter(x,rep(1,n), sides=1)}
```

It is easy to adapt to sum only preceding values, if this is what you really want.

Running sums for every row of the previous 25 rows

Solution

Problem