Top Vendor and Range Sum (cumulative Sum)

[Sara_3]

Vendor Name	Last 6 Months Sales	Cumulative Sum	Total (Cumulative Sum)
	total = 5500
A	1200	1200	1200/5500
B	2500	3700	3700/5500
C	800	4500	4500/5500
D	1000	5500	5500/5500

I get these calculations in front end but I need only top vendors according to Cumulative Sum and Total Cumulative Sum in back end.

Last 6 Months Sales == Sum({<Date = {"<=$(vCurrentDay)"},Date= {">=$(v6MonthsAgo)"},[SA Status]={' Receipt'}>} [Sales])

Cumulative Sum = RangeSum(Above(TOTAL Sum({$<Date = {"<=$(vCurrentDay)"},Date= {">=$(v6MonthsAgo)"},[SA Status]={' Receipt'}>} [Sales]), 0, RowNo(TOTAL)))

Requirement:

The above one is sample data in table to explain the calculations, I need top vendors and all calculations need to be in Load script . the requirement is :

Look at  Vendor's  sale in the last 6 months and calculate the total at the Vendor level, order that table from high to low. Then create a cumulative sum (so Vendor #1 shows  Vendor 1 sales,  Venodr #2 shows  Vendor #1 AND Vendor #2 sales, and so on). Whenever [Cumulative Sum] < Sum(Total [Cumulative Sum])*.8 then [Top Vendor] = "Y"

1- how to get Sum(sales ) (Asc) order ------------as column 2

2- how to get cumulative SUM---------------------as column 3

3- how to get SUM(Total Cumulative SUM)-----as column 4

4- if Statement to get top Vendor = Y

I tried the aggr and RangeSUM functions in load editor to get the top Vendors.

Output Table: Needs to show top Vendors according to above requirement , I need to show Last 6 months sales (high to low).