Cumulative Sum of a column for only the Distinct values of another column

[zaza]

I have the following cummulative count measure whihc works fine:

Count = 
    CALCULATE ( 
        DISTINCTCOUNT ( 'X Data'[Story ID] ), 
        FILTER ( ALLSELECTED ( 'Date' ), 'Date'[Date] <= MAX ( 'Date'[Date] ) ), 
        USERELATIONSHIP ( 'Date'[Date], 'X Data'[_Story-Sprint Start] ) 
    )

However I would like to SUM another column but only for the distinct values (so basically ignoring duplicate rows)

SUM = 
    CALCULATE ( 
        SUM ( 'X Data'[Story Pints] ), `<-But only for the Distinct of Story ID` 
        FILTER ( ALLSELECTED ( 'Date' ), 'Date'[Date] <= MAX ( 'Date'[Date] ) ), 
        USERELATIONSHIP ( 'Date'[Date], 'X Data'[_Story-Sprint Start] ) 
    )

[amitchandak]

@zaza , Try like

SUM =
CALCULATE (
SUMX( Summarize('X Data','X Data'[Story ID] , 'X Data'[Story Pints]), [Story Pints] ), // `<-But only for the Distinct of Story ID`
FILTER ( ALLSELECTED ( 'Date' ), 'Date'[Date] <= MAX ( 'Date'[Date] ) ),
USERELATIONSHIP ( 'Date'[Date], 'X Data'[_Story-Sprint Start] )
)