help creating a column that is a cumulative sum based on other columns
I am trying to create a new column in JSL that will be an ongoing sum of the previous rows in that column. I have a column called "Total Daily Flow" I also have a column which marks what location the data in "total daily flow came from (call that "Site"). for example, Say on Oct. 1, (which is specified in another column called "day of water year") i have a total daily flow of 1000, and this day...
