get the last N weeks data

[amirabedhiafi]

I have the following model : 

I want to calculate using DAX the Last N Weeks Covid cases excluding the current week. The numbers should change dynamically with the What-if-Parameters selection. The parameter starting from 2 and increasing incrementally by 1 till 28 weeks.

This is my expected output :

[Deepanshi_Ranka]

Hi @amirabedhiafi ,

Were you able to link this to parameter? Can you share your solution?

Thanks.

[amitchandak · Accepted solution]

@amirabedhiafi , Refer my post on WOW, You can create Week Rank in You date table and Use that.

Last 2  weeks = CALCULATE(sum('order'[Qty]), FILTER(ALL('Date'),'Date'[Week Rank]>=max('Date'[Week Rank])-2 && 'Date'[Week Rank]<=max('Date'[Week Rank])))

The above two can come from what if measure

Power BI — Week on Week and WTD
https://medium.com/@amitchandak.1978/power-bi-wtd-questions-time-intelligence-4-5-98c30fab69d3
https://community.powerbi.com/t5/Community-Blog/Week-Is-Not-So-Weak-WTD-Last-WTD-and-This-Week-vs-La...
https://www.youtube.com/watch?v=pnAesWxYgJ8

[whatisdata96]

How do you get week rank once you have WeekEND Date established in your date table?

[amirabedhiafi]

@amitchandak I modified it to : 

Last2weeks = CALCULATE(SUM('COVID Data'[COVID Cases]), FILTER(ALL('Date'),'Date'[Week Rank]>=max('Date'[Week Rank])-WeekRank[WeekRank Value] && 'Date'[Week Rank]<=max('Date'[Week Rank])))

after creating the Week Rank Calculated Column in the Dimension Date.

But I can't see the value : 

[amirabedhiafi]

How can I link Last 2  weeks  to the parameter?