Qlik Sense moving average line for date

[Anonymous]

I am trying to create an alternative measure in a line chart to calculate a moving average. 

Currently I have two dimensions in my line chart
1. Products
2. Date

The average line needs to be moving/dynamic by date ( found on the x-axis). It needs to find the average for where the products are "A1" and "A2" (see formula below)

I tried the following formula but it shows a flat across all months so it's currently not dynamic based on date:

=(sum({<product_id={'A1','A2'}>} TOTAL <date> value)/sum({<total_products>} TOTAL <date> value))

[Gysbert_Wassenaar]

See this document: https://community.qlik.com/t5/QlikView-Documents/Calculating-rolling-n-period-totals-averages-or-oth...