Difference between values in same column

[mh2587]

Hi I hope you are Doing well I am trying to calculate the difference of followers like the expected difference  any one who help me in this 

thank you

Month	Social Platform	Followers	Expected Difference
April	Facebook	303	0
May	Facebook	334	31
June	Facebook	347	-13
July	Facebook	350	-3
August	Facebook	366	-16
September	Facebook	371	-5
October	Facebook	374	-3
November	Facebook	389	-15

[Anonymous · Accepted solution]

Hi @mh2587 ,

I created a sample pbix file(see attachment), please check whether that is what you want.

1. Create a calculated column to get the month number

Month Number = SWITCH('Table'[Month],"January",1,"February",2,"March",3,"April",4,"May",5,"June",6,"July",7,"August",8,"September",9,"October",10,"November",11,"December",12)

2. Create a measure or calculated column to get the difference

Expected Difference = 
VAR _premonth =
    CALCULATE (
        MAX ( 'Table'[Month Number] ),
        FILTER (
            ALL ( 'Table' ),
            'Table'[Month Number] < EARLIER ( 'Table'[Month Number] )
        )
    )
VAR _prefol =
    CALCULATE (
        SUM ( 'Table'[Followers] ),
        FILTER ( ALL ( 'Table' ), 'Table'[Month Number] = _premonth )
    )
RETURN
    IF ( ISBLANK ( _prefol ), 0, 'Table'[Followers] - _prefol )

Best Regards

[mh2587]

@amitchandak @AlexisOlson Can you guys help me in this will be appreciated

[amitchandak]

@mh2587 , 

hope you have date else create date column like

date = datevalue("01-"&[Month] &"-2021")

then create a new column like
new column =
var _max = maxx(filter(Table, [Date] <earlier([Date])),[Followers])
return
[Followers] - maxx(filter(Table, [Date] = _max ),[Followers])

In case you need measures , you can use time intelligence with date table  

Power BI — Month on Month with or Without Time Intelligence
https://medium.com/@amitchandak.1978/power-bi-mtd-questions-time-intelligence-3-5-64b0b4a4090e
https://www.youtube.com/watch?v=6LUBbvcxtKA

[mh2587]

Its not working giving the same value in the output

[amitchandak]

@mh2587 , Sorry , My ba. In max you have to return date

new column =
var _max = maxx(filter(Table, [Date] <earlier([Date])),[Date])
return
[Followers] - maxx(filter(Table, [Date] = _max ),[Followers])

[mh2587]

Still not getting the desired output