Do formulas with values of previous rows

[Abevann]

Guys,

I need to get a value from a previous row, but I'm having troubles in order to do so. An example, This is the table that I'm looking for:

Date            Fruit      Buy Sold Stock         Buy - Sold = Stock

1/8/2021     Lime     90     70     20            90 - 70 = 20

5/8/2021     Orange 60     50    10             60 - 50 = 10

7/8/2021     Lime     70     80    10             90 (70 + 20) - 80 = 10

At the end of August 7th, there are 10 limes and 10 oranges in stock. I tried with LOOKUPVALUE and some others, but with no success so far. 

Any idea how to solve this? Thanks!

[Anonymous · Accepted solution]

Hi @Abevann ,

You can create a measure or calculated column as below to achieve it, please find the details in the attachment.

1. Create a measure

Stock in previous row = 
VAR _curdate =
    SELECTEDVALUE ( 'Table'[Date] )
VAR _predate =
    CALCULATE (
        MAX ( 'Table'[Date] ),
        FILTER ( ALLSELECTED ( 'Table' ), 'Table'[Date] < _curdate )
    )
RETURN
    CALCULATE (
        MAX ( 'Table'[Stock] ),
        FILTER ( ALLSELECTED ( 'Table' ), 'Table'[Date] = _predate )
    )

2. Create a calculatd column

Column = 
VAR _predate =
    CALCULATE (
        MAX ( 'Table'[Date] ),
        FILTER (   'Table' , 'Table'[Date] < EARLIER('Table'[Date]) )
    )
RETURN
    CALCULATE (
        MAX ( 'Table'[Stock] ),
        FILTER ( 'Table' , 'Table'[Date] = _predate )
    )

In addtion, you can also refer the method in the following links to achieve it.

Get previous row in Power Query - EXPLAINED

get value from Previous row

Calculate previous row using DAX

Best Regards

[Abevann]

Thanks @Anonymous !

[Greg_Deckler]

@Abevann Looks like a variation on MTBF: 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

[Abevann]

Thanks @Greg_Deckler ,

Tha solution works, but I had the problem that the information if from different tables. I'm struggling with this, but it does what I was looking for.

Thanks, regards,