How to calculate the cumulative sum in a 3 dimensions table?

[#1]

Hello to all,

I'm looking for the formula to calculate the cumulative sum in a table with 3 dimensions.

For clarity I attach an example of the results that I would get.

Thanks to everyone who can help me.

Year	Month	Agent	Sum(Amount)	?
2012	1	A	100	100
2012	1	B	80	80
2012	2	A	100	200
2012	2	B	80	160
2012	3	A	100	300
2012	3	B	80	240
2012	4	A	100	400
2012	4	B	80	320
2012	5	A	100	500
2012	5	B	80	400
2012	6	A	100	600
2012	6	B	80	480
2012	7	A	100	700
2012	7	B	80	560
2012	8	A	100	800
2012	8	B	80	640
2012	9	A	100	900
2012	9	B	80	720
2012	10	A	100	1000
2012	10	B	80	800
2012	11	A	100	1100
2012	11	B	80	880
2012	12	A	100	1200
2012	12	B	80	960

[#2]

Maybe not the prettiest expression, but you could try this:

If(Agent='A', RangeSum(Above(TOTAL Sum({$<Agent*={A}>}Amount), 0, RowNo(TOTAL)))

,If(Agent='B', RangeSum(Above(TOTAL Sum({$<Agent*={B}>}Amount), 0, RowNo(TOTAL)))))

[#3]

Thank you Anton, your response functions in this specific case, but I'd like to find a more generic formula, something that works regardless of the number of elements in the third dimension.

Also I would like the values ​​come back to zero when the year changes.

Here below is the table that results from your formula.

Year	Month	Agent	If(Agent='A', RangeSum(Above(TOTAL Sum({$<Agent*={A}>}Amount), 0, RowNo(TOTAL))) ,If(Agent='B', RangeSum(Above(TOTAL Sum({$<Agent*={B}>}Amount), 0, RowNo(TOTAL)))))
2012	1	A	100
2012	1	B	80
2012	2	A	200
2012	2	B	160
2012	3	A	300
2012	3	B	240
2012	4	A	400
2012	4	B	320
2012	5	A	500
2012	5	B	400
2012	6	A	600
2012	6	B	480
2012	7	A	700
2012	7	B	560
2012	8	A	800
2012	8	B	640
2012	9	A	900
2012	9	B	720
2012	10	A	1000
2012	10	B	800
2012	11	A	1100
2012	11	B	880
2012	12	A	1200
2012	12	B	960
2013	1	A	1270
2013	1	B	1070
2013	2	A	1340
2013	2	B	1180
2013	3	A	1410
2013	3	B	1290
2013	4	A	1480
2013	4	B	1400
2013	5	A	1550
2013	5	B	1510
2013	6	A	1620
2013	6	B	1620
2013	7	A	1690
2013	7	B	1730
2013	8	A	1760
2013	8	B	1840
2013	9	A	1830
2013	9	B	1950
2013	10	A	1900
2013	10	B	2060
2013	11	A	1970
2013	11	B	2170
2013	12	A	2040
2013	12	B	2280