Moving average using variable table

[jinxiang]

Dear all,

I'm new to Power BI and this community. While exploring how to calculate moving average of a simple dataset, I came across an unexpected result that I could not explain.

The data is simple: a sales table with an amount and date column. I subsequently created a calendar table and did a moving average calculation (found online, see green box below). However, when the "summarize" part of the code was brought out as a variable, the calculation gave an unexpected result (see red box below).

However, i'm not sure the second measure gave unexpected values.

Any pointers or link to the relevant topic of why this is so, will be greatly appreciated.

Thank you very much!

Rgds,
Jinxiang

[lbendlin]

The difference comes from the way CALCULATE and SUMMARIZE interact.  

Here's an excellent article that describes the basic idea

https://www.sqlbi.com/articles/row-context-and-filter-context-in-dax/