DAX rolling average using ALLSELECTED

[dicken]

Hi, I have a question regarding the use of allselected , I've seen a few examples of rolling averages where this used;

Copy of Average :=
VAR madate =
    MAX ( pTaverage[date] )
VAR anser =
    CALCULATE (
        AVERAGEX ( pTaverage, pTaverage[units] ),
        FILTER ( ALLSELECTED ( pTaverage[date] ), pTaverage[date] <= madate )
    )
RETURN
    anser

But I'm not sure why it's used, I've replaced it with ALL , as I would use in a running total and the results seem the same.
I'm very shakey ALLSELECTED, I can see what it does with a slicer but not sure about other external influences.

Any help welcome.

Richard.

 

[Matt Allington]

ALL removes all filters regardless where they come from. ALLSELECTED WILL REMOVE ALL FILTERS inside a visual, but will keep filters applied via slicers in another visual.
i wrote this article about ALL that may help you

https://exceleratorbi.com.au/the-all-function-in-dax/

 

[dicken]

Thanks,

Richard.