A line chart with weeknumbers as the dimension. In the graph I want to display sum of sales, but the values should be the comparison of the week to the week before. For example, the sum of sales value for week 7 should be the sum of sales for week 7 compared to the sum of sales for week 6. Week 8 would display the comparison between week 8 and week 7 etcetera. I have Dates/Weeknumbers but I can't get the measure to work. It either displays the the same value as the actual week or just plain 0.
I've been trying set analysis and using AGGR but no succes so far. Any ideas?