Trailing Week Average

[Anonymous]

Hi everyone, 

I have just started using Power BI and DAX however I have been struggling with a trailing average measure. My data is sorted like the example data below.

The problem I am having is that all functions seem to aim at dates instead of week numbers.

What formula could create a trailing average for 12 weeks excluding the current week? 

Kind regards, 

Majesteit 

Week No	Salesvalue	Parameter 1	Parameter 2
1	345	Promo	Store
1	34	Regular	Online
2	21	Promo	Store
2	1245	Regular	Online
3	5636	Promo	Store
3	37	Regular	Online
4	35	Promo	Store

[Anonymous]

Dear Greg, 

Thank you for the response, it is working for the individual sales values however I need the sum of the entire week and then the average for the sum of the different weeks. 

Kind regards 

[Greg_Deckler]

@Anonymous You will need to do something like:

Measure = 
  VAR __CurrentWeek = WEEKNUM(TODAY())
  VAR __StartWeek = __CurrentWeek - 13
RETURN
  AVERAGEX(FILTER('Table', [Week No] >= __StartWeek && [Week No] < __CurrentWeek),[Salesvalue])