Help with Previous Value

[rpaiva99]

Greetings,

I'm trying to create a column where if the value of the column [VALOR DO LITRO ORIGINAL] = null, the cell brings the previous value of [VALOR DO LITRO ORIGINAL], as in the image example.

I tried in different ways, but without success.

[rpaiva99]

That was the result generated by this formula, it is approximate but not exactly what I seek

[Greg_Deckler]

@rpaiva99 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