I have a data table in R which I want to count the number of overlapping windows for. This is essentially a pileup command and seems to be something that could be done using bedtools, but I can't figure out how to do so without leaving R.

Is there an R function to do this already, or any suggestions about what may be an efficient approach?

In case it's helpful, here is a mini example of what I'm trying to do. Thanks in advance!

input:

```
chrom    start     end
1        1         100
1        50        150

```

returns:

```
chrom      start    end    count
1        1          49      1
1        50         100     2
1        101        150     1

```