Difference between Rows of same Value Column for same ID using DAX

[Stuznet1]

Hi,

I'm struggling to transform the dataset below.

So basically I want to Calculate the difference group by ID

For instance: 
Take the original value and subtract the value by the latest Modified date to get the difference. 

From this

To this.

Any help would be appreciated.

[Greg_Deckler · Accepted solution]

@Stuznet1 See my article on Mean Time Between Failure (MTBF) which uses EARLIER: http://community.powerbi.com/t5/Community-Blog/Mean-Time-Between-Failure-MTBF-and-Power-BI/ba-p/3395....
The basic pattern is:
Column = 
  VAR __Current = [Value]
  VAR __PreviousDate = MAXX(FILTER('Table','Table'[Date] < EARLIER('Table'[Date])),[Date])

  VAR __Previous = MAXX(FILTER('Table',[Date]=__PreviousDate),[Value])
RETURN
  __Current - __Previous