Help needed for month-on-month change visuals

[Natrify]

Hi all,

I've been working on a dashboard for app usage, which is near completion, but there's just one visual that I can't quite iron out. I'm trying to create a visual showing month-on-month % change in app usage:

The data I'm working with looks something like this:

 I've managed to get something close to what I want by using calculated columns to get a count of each month, and then get a count of the previous month, then I calculate the % difference:

The problem with this method is that if I create a filter visual for User Type, it doesn't effect the data in the right way. e.g. If I filter for User Type 0 it will filter out rows with 1, but the % Differencemonth doesn't change.

Any ideas? Help is much appreciated.

[FarhanAhmed · Accepted solution]

rather than creating column for % change or %, it is always better to create measure.

try create measure like this 

% Diff = 
Var LM =  CALCULATE(SUM(YourTable[InstanceCount]), PARALLELPERIOD(DateTable[DateKey],-1,Month))  
VAR CM = SUM(YourTable[InstanceCount])

Return 
DIVIDE (CM-LM,LM,BLANK())

[Natrify]

Just a quick update, if you're like me and you added in an instance count column to your table, using COUNT works better than SUM: 

% Diff = 
Var LM =  CALCULATE(COUNT(YourTable[InstanceCount]), PARALLELPERIOD(DateTable[DateKey],-1,Month))  
VAR CM = COUNT(YourTable[InstanceCount])

Return 
DIVIDE (CM-LM,LM,BLANK())

Using SUM can result in wonky percentages since you end up muliplying counts with themselves:

Month	Instance count	Row number	Sum
Jun-23	26,713	26,713	713,584,369
May-23	20,482	20,482	419,512,324
	% differenceCOUNT		% differenceSUM
	30%		70%

[Natrify]

Brilliant! 

I got it working, I got pretty close to your measure, I jsut couldn't figure out how to get a sum of the previous month's data. I didn't even know PARALLELPERIOD existed. 

Thankyou so much!