YTD with YearMonth as X-axis and having second dimension as Product

[#1]

How to Calculate Cumulative sum like below(YTD) when I am having multiple dimensions like YearMonth and Product.

Example:

Data:

YearMonth,Product,Amount

Jan 12,A,10

Feb 12,B,20

Mar 12,C,5

Apr 12,D,15

I want the output as below

YearMonth      Amount

Jan 12              10

Feb 12              30

Mar 12               35

Apr 12                50

Kindly advice.

[#2]

Try

Rangesum(above(sum(Amount),0,rowno()))

[its_anandrjs]

Write like

Dimension:- YearMonth

Expression:- RangeSum(ABOVE(SUM(Amount), 0, ROWNO()))

[#4]

I want to have multiple dimensions . With above expressions I can get it by YearMonth.

But I need YearMonth as First Dimension and Product as second dimesion.Product need to get stacked in bar chart.

Then above output is needed.