KB221335: How to display moving average values in a report such that every value uses the full moving average window size

Users may notice that the first values of a moving average metric are not calculated based on the full window size, even though the data exists in the warehouse.
 
For example, if a report contains a metric that is the 3-month moving average of Units Sold, the first month moving average will be calculated based on one month, the second month moving average will be calculated based on two months, the third month and later will be calculated based on the full window size of 3 months.
 

 
This is the expected behavior of the moving average function. If the report contains a filter, the necessary data is not returned from the warehouse to calculate a 3-month moving average for the first two months. Users can modify the report so that only 3-month moving average values are seen. This can be accomplished by following the steps below.
 

• Verify that the moving average metric has been created correctly. See KB7137 for more information about using the moving average function.
• Modify the report filter to bring back all necessary data from the warehouse. In the example above, the report filter would need to be modified to bring back data for Nov 2011 and Dec 2011.
• Create a new derived metric in the report.
  

• Create the derived metric so that it has the value of the first time period to be seen on the report.  For a 3-month moving average metric, the derived metric should be:

• 
  (Min(Month) {} + 2)

  
  
• Create a view filter to filter out the undesired rows.  For the 3-month moving average example, Nov 2011 and Dec 2011 should be hidden from the report.  Now the report will show the desired months, and will show a 3-month moving average for all months.