DAX_Weekly percentage

[Anonymous_]

How would I write the following formulas in DAX: 

If you see in the last two columns, I have written the formulas and the Last column is how the Excel formula looks like, which is, Cost(a)/Sum of Cost for week 1, and so on and so forth for each product. Essentially we want to be able to find Cost Percentage per week per product. I'm not able to grasp the exact formula for this in DAX.

Thanks for the help!:)

[FreemanZ]

hi @Anonymous_ 

try to add a column like this:

Cost%2 = 
DIVIDE(
    [Cost],
    SUMX(
        FILTER(
            TableName, 
            TableName[Week]=EARLIER(TableName[Week])
        ),
        TableName[Cost]
    )
)

[FreemanZ]

if you feel more comfortable with CALCULATE, it looks like this:

Cost%3 = 
DIVIDE(
    [Cost],
    CALCULATE(
        SUM(TableName[Cost]),
        ALLEXCEPT(TableName, TableName[Week])
    )
)

@Anonymous_