I have a data frame of start time, end time in UNIX time stamp and category, as below:
I want to find the overlaps of one category say "a" among other categories "b" & "c" and same for other categories. I want to find how many number of categories overlapped how many times e.g. 2 categories overlapped 3 times and 3 categories overlapped 5 number of time. And also the average of duration they overlapped for as shown below.