DAX measure for comparing rows and time difference

[ellac]

Hi,

I'm trying to build a measure (called Time Diff) that compares two consecutive rows, in this case the rows in the Time column. As shown in the column on the far right, I want the output to be in seconds, i.e. between row 1 and 2 it's 36 seconds, between row 2 and row 3 it's 53 seconds and so on.

If possible, I want to achieve this result by using a measure, not a calculated column. I've read about how to solve similar problems by creating a calcualted column using the EARLIER function.

Thanks in advance!

/Ella

[Greg_Deckler]

@ellac 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

[SpartaBI · Accepted solution]

@ellac create this measure:

Time Diff = 
VAR _current_time = SELECTEDVALUE('Table'[Time])
VAR _previous_time = 
    MAXX(
        FILTER(
            ALL('Table'),
            'Table'[Time] < _current_time
        ),
        'Table'[Time]
    )
VAR _result = (_current_time - _previous_time) * 86400
RETURN
    IF(
        NOT ISBLANK(_previous_time), 
        _result
    )

      

Showcase Report – Contoso By SpartaBI

[ellac]

Thanks for your answer! Almost there... 🙂 _previous_time returns _current_time - 1 sec, i.e. the previous timestamp. For example _previous_time for Time 07:06:13 becomes 07:06:12.

[ellac]

Solved it! Just replaced the ALL function with ALLSELECTED. Thanks for your help @SpartaBI 🙂

[SpartaBI]

@ellac my pleasure 🙂
Check out my showcase report - got some high level stuff there. Sure you will find there a lot of cool ideas. 
https://community.powerbi.com/t5/Data-Stories-Gallery/SpartaBI-Feat-Contoso-100K/td-p/2449543
Give it a thumbs up over there if you liked it 🙂