-Something like "can't find row being referred to".
I've tried creating it as a measure, as a column, decomposing the equation into multiple columns/functions, etc. I am at a bit of a wall and I would greatly apprecaite any help.
It's google analytics data so it looks roughly like this:
Month of the Year
I'm quite comfortable transforming and shaping the data in excel, but I would really like to be able to shape my data in powerbi as it seems I've just misunderstood how to apply a dax expression as opposed to do all my data transformation in excel and then simply importing.
The 2 concepts "you must have a calendar table to use inbuilt time intelligence" and "you don't have a mark as date table feature in Power BI" are completely independent. You do need a calendar table if you want to use inbuilt time intelligence. The reference at SQLBI is related to the use of surrogate keys between a date table and a data table. In Excel you can use surrogate keys and use the "mark as date table feature". In Power BI you must use a date column.
* Matt is a Microsoft MVP (Power BI) and author of the Power BI Book Supercharge Power BI.
I followed the steps above to create the moving average however I get an error stating that there are duplicates in my DATESINPERIOD column (this is because there are and there are supposed to be...). I was hoping it would add all the values for one day together and then average these - do you have any suggestions?