DAX Rolling 7 Day Average in User Selected Period

[hwr7dd]

Hello,

I have data like so:

7 Day Rolling Census =
VAR sumper =
    CALCULATE (
        SUM ( 'Pace Alert Rollup'[Census] ),
        DATESINPERIOD (
            'Pace Alert Rollup'[Date],
            MIN ( 'Pace Alert Rollup'[Date] ),
            -7,
            DAY
        )
    )
VAR daysinperiod =
    CALCULATE (
        DISTINCTCOUNT ( 'Pace Alert Rollup'[Date] ),
        DATESINPERIOD (
            'Pace Alert Rollup'[Date],
            MAX ( 'Pace Alert Rollup'[Date] ),
            -7,
            DAY
        )
    )
RETURN
    sumper / daysinperiod

I want the user to be able to select the period which the 7 day rolling average is running. For example:

This table shows with a max date of 1/07 and no min date (starting rolling period from minimum of data in the dataset).

This table filtered out the first couple days of the dataset, but still starts the rolling calculation as if there was no date filter. This table should read something like this:

Date	Rolling Census	Census
1/03/21	2199	2199
1/04/21	2246 ((2199+2293)/2)	2293
1/05/21	2312((2199+2293+2445)/3)	2445
1/06/21	2349((2199+2293+2445+2459)/4)	2459
1/07/21	2375((2199+2293+2445+2459+2483)/5)	2483

So essentially Im wondering how to get that DATESINPERIOD function to take the dates set by a filter instead of those in the dataset. 

[amitchandak · Accepted solution]

@hwr7dd , I think you have take cumm approch with allselected . assuming date range is selected 

Cumm Avg= divide( CALCULATE(SUM(Sales[Sales Amount]),filter(allselected(date),date[date] <=max(date[date]))) ,
CALCULATE(distinctcount(Date[Month-Year]),filter(allselected(date),date[date] <=max(date[date])), not(isblank(Sales[Sales Amount]))))

or like

Cumm Avg= divide( CALCULATE(SUM(Sales[Sales Amount]),filter(allselected(date),date[date] <=max(date[date]) && date[date] >=max(date[date])-7)) ,
CALCULATE(distinctcount(Date[Month-Year]),filter(allselected(date),date[date] <=max(date[date]) && date[date] >=max(date[date])-7 ), not(isblank(Sales[Sales Amount]))))

[hwr7dd]

@amitchandak 
Sometimes I can't believe how hard you work, and how much you know looking through these forums. Thanks!

[hwr7dd]

Also, quick note for anyone who may find this in the future, I had to change -7 days to -6 days to line up with my correct rolling 7 day avg.