Cumulative sum of a column based on another columns in expression editor

[freceena]

I have to get cumsales field by the summation of sales for months and cum_category_count should be the cumulative count of category with respect to category and month. Could anyone please suggest a solution for this?

[dplr-rn]

you need an expression something like this

=Aggr(RangeSum(Above(Sum(sales), 0, RowNo())), category, (date, (NUMERIC))).

attached output from my  sample data