Cumulative time graph

[#1]

We want to follow the evolution of the customers who had buyed last year and who came back this year until the month we selected.

We wrote this formula :

Count({< IDC = P({<IDC -= {'0'},  Annee={$(=Max(Annee))}>} IDC)*P({<IDC -= {'0'}, Annee={$(=Max(Annee)-1)}>} IDC)>} distinct IDC)

It work fine.

But, when we put it in a bar graph, we don't have the same result :

When we select 1 month : OK

But, when we select 2 month, the result is wrong in the bar graph :

The result is false for the last month, and the first month is not good.

can somebody help me ?

Thanks.

Regards.

[#2]

i think the problem is there is no intersect between the first month and the second month. How can  i modify the formula to make this intersect in the graph :

First month = first month

Second month = intersect ( intersect(M1 2014, M2 2014), 2013)

Thanks

[MarcoWedel]

please post sample application

thanks

cordialement

Marco