Calculate Percentage Change from Previous Row

[pfarahani]

Hello,

I am trying to create a DAX measure to get the Percentage Change from Month to Month. Problem is I do not have a traditional Dates table, my Dates table is more like a String table with Dates. 

Here is the visual i am trying to create:

-- The number of filings in here is a simple measure, and then I use a domension table to get the court names, and then i use my dates dimension (not really a dates table) to get the Year month

I want another column that has percentage change showing., but I cant use PREV MONTH syntax for the measure because my dates table is not marked Dates. 

What I did in my dates table, I created a Index, so that at least I can Rank my row to get the dates in order:

 Thanks

[amitchandak · Accepted solution]

@pfarahani , Try like this example , Date here us your Month year table

This Month = CALCULATE(sum('order'[Qty]), FILTER(ALL('Date'),'Date'[index]=max('Date'[index])))
Last Month = CALCULATE(sum('order'[Qty]), FILTER(ALL('Date'),'Date'[index]=max('Date'[index])-1))

diff = [This Month]-[Last Month]
diff % = divide([This Month]-[Last Month],[Last Month])

[pfarahani]

@amitchandak , worked out pretty nice i think, 1 small issue remains. Below is the chart, not bad, however my data ends with December 2019, but its still trying to calculate for the January 2020. Is their a solution using ISBLANK or an IF to stop after Dec 2019. thanks 

[pfarahani]

@amitchandak I think I got something here, 

I took the code you provided for diff% and modify to this:

diff % = IF( ISBLANK('_Measures Table'[This Month])

, BLANK(), DIVIDE([This Month]-[Last Month],[Last Month]))

Seems to work nice. One more question, the part i circled at the top, what is it calculating there? thanks