Difference between most recent value and last value

[pawelj795]

Hi,
I'm currently calculating the difference in Facebook likes between the last update and the most recent update.
Our updates vary, sometimes after 7 days, sometimes after 10 days, sometimes after 14 days.

How can I automate this case so that it works every time?

The breakdown by country is not important.

[Greg_Deckler]

@pawelj795 - Not sure I 100% follow but I think:

Measure =
  (MAX([Update Date]) - MIN([Update Date]) * 1.

Kind of interested how you get fractional Likes. 

[pawelj795]

@Greg_Deckler 
Thanks for weighing in.

Fractional likes come from rounding percentages 😉 They are not important.

I show below example of my desired results.
I want to calculate difference between value in blue circle and value in red circle.

[Greg_Deckler]

@pawelj795 - Ah, you need Lookup Min/Max - https://community.powerbi.com/t5/Quick-Measures-Gallery/Lookup-Min-Max/m-p/985814#M434

Basically, 

Measure =
  VAR __MinDate = MIN('Table'[Update Date])
  VAR __MaxDate = MAX('Table'[Update Date])
  VAR __MinValue = SUMX(FILTER('Table',[Update Date] = __MinDate),[Likes])
  VAR __MaxValue = SUMX(FILTER('Table',[Update Date] = __MaxDate),[Likes])
RETURN
  __MaxValue - __MinValue

[pawelj795]

@Greg_Deckler 

I don't think that MIN is appropriate in this case.

I need the difference between the most recent value and the second recent value as I shown in the previous photo.
Look at my measure, I only need the last part.

[Greg_Deckler · Accepted solution]

@pawelj795 - Sorry, I always mess up dates in non-US form.

Measure =
  VAR __MaxDate = MAX('Table'[Update Date])
  VAR __2ndDate = MAXX(FILTER('Table',[Update Date]<>__MaxDate),[Update Date])
  VAR __2ndValue = SUMX(FILTER('Table',[Update Date] = __2ndDate),[Likes])
  VAR __MaxValue = SUMX(FILTER('Table',[Update Date] = __MaxDate),[Likes])
RETURN
  __MaxValue - __2ndValue

[pawelj795]

@Greg_Deckler 
Thanks that works perfectly! I was exactly looking for that.

By the way, I have the same issue with US date format 😉

[Greg_Deckler]

@pawelj795 - Sweet!

[harshnathani]

HI @pawelj795 ,

See if this helps

https://community.powerbi.com/t5/Community-Blog/Getting-Previous-Values-in-Power-BI-Part-1/ba-p/1143...

Regards,

Harsh Nathani