How to create a cumulative percentage by month ?

[#1]

Hi everyone,

This is my first post on the qlik community

I try to have the percentage of buyers of a product vs a set of product ({<Product=p(ProductParent)>}) cumulative by month

if it was not cumulative, i could use this function. : =sum(buyer)/sum({<Product=p(ProductParent)>}buyer)

Exemple with only 2 Months

January : 3 buyers vs 5 in total

February : 7 buyers vs 15 in total

i would like to have a table with

January 60% (3/5)

February 50% ((3+7)/(5+15))

At the end, i should be able to select any range of Months.

Do you have an Idea how to proceed ?

For information:

I put Month variable in Dimension of my table but i don't think is a good idea.

I try to modify SetExpression but it seems it applies to all the table and not just on the Month category.

I can't create all possibilitites of cumulative Months

But maybe can I create a calculated dimension which represents cumulative Month ? ==> but i don't know how to proceed

Thank you for your answers.

[MK_QSL]

Working, still helpful ?

[#3]

Yep, Above function is just what I needed

Thank you a lot for you quick answer and have a nice day !