Break down Running Total into separate cases

[Anonymous]

Hello Everybody,

I've seen lots of explanations to create a running/accumulating total, however the raw data I have begins with a running total and I would like break this down to the value added on. Simple enough in Excel, I believe, but I would rather do it in BI. 

I am looking at California's Testing rate for COVID-19 and would like to create a Calculated Column called DailyNewTests:

Which is to say, the first value would be 6291, the second would be 11487-6291 = 5196, the third would be 12528 - 11487 = 1041 and so on..

Would anyone be able to help me? Much appreciated! 

[amitchandak]

@Anonymous ,

If you have non continous date

column =
var _last_date =maxx(filter(Table,Table[Date] <earlier(Table[Date])),Table[Date])
return  Table[accumulated total]-maxx(filter(Table,Table[Date] =_last_date),Table[Date])

continuous Date

Total = Table[accumulated total]-maxx(filter(Table,Table[Date] =earlier(Table[Date])),Table[Date])

Refer this to have measures https://medium.com/@amitchandak.1978/power-bi-day-intelligence-questions-time-intelligence-5-5-5c3243d1f9

[camargos88 · Accepted solution]

Hi @Anonymous ,

Try this code for a calculated column:

Column = 
VAR _previousDate = CALCULATE(MAX('Table'[Date]), FILTER('Table', 'Table'[Date] < EARLIER('Table'[Date])))
RETURN
     'Table'[Values] - CALCULATE(SUM('Table'[Values]), FILTER('Table', 'Table'[Date] = _previousDate))