Create a MTH measure from a YTD column

[Hchazelle]

Dear all,

I have a table with a column YTD Actuals VS LY with a YTD value for each month.

I am trying to calculate a MTH Actuals VS LY from this YTD data.

To do this, I am planning to first make a measure to calculate the previous month YTD Actuals VS LY and then substract it to the YTD Actuals VS LY

To calculate the previous month YTD Actuals VS LY, here is the measure I made:

=CALCULATE([ACT_VS_LY@CR];PREVIOUSMONTH('Calendar'[date]))

As you can see in TEST measure, it is working, except that for the month of January 2021 (202101) I have the 364 from December while for January i should always have 0.

I created a date table linked to my data table.

Could you please help me find a way so that if the year of previous month is not the same as the year of my filter context, then the measure returns 0 ?

Thanks for your help !

Henri

[amitchandak · Accepted solution]

@Hchazelle , Try a measure like

measure =
var _1 = CALCULATE([ACT_VS_LY@CR];datesMTD('Calendar'[date]))
var _2 = CALCULATE([ACT_VS_LY@CR];PREVIOUSMONTH('Calendar'[date]))
return
Switch( True() ,
not(isblank(_1) ) && not(isblank(_2) ) , _1 - _2 ,
isblank(_1) , 0,
isblank(_2),_1
)

[Hchazelle]

Thanks a lot, that's perfect !