问题
Looking to get a moving average and aggregate sum over years by specific months over 3 years, not monthly rolling average. I want to see how our business trends by month over the years and want to have the average as a baseline.
ie:
January 2011, January 2012, January 2013, etc
February 2011, February 2012, February 2013, etc
So far all I have been able to do is get a 3 year SUM from selected year, and even that is off.
Ex: selected month = Jan 2013, aggregate includes all months from February 2011 -->Jan 2013. Instead I need just January for those years.
date measure tried:
CALCULATE([total],
DATESINPERIOD(Time[Pk_Date],
LASTDATE(Time[PK_Date]),-3,Year
)
)
Goal is to roll back 3-years from selected year
- January
- 2011: 50
- 2012: 55
- 2013: 53
- 2014: 57
- 2015: 47
In this scenario rolling avg and running totals should be:
2013 avg = 53 | sum = 1582014 avg = 55 | sum = 165
2015 avg = 52 | sum = 157
any help is appreciated!
回答1:
You're super close, you just missed the extra filter to filter that date period you selected down to the selected month number.
First, make sure there's a column for the month number in your date table. Let's assume it's called MonthNumber.
Next, create a measure to capture your selected month.
ChosenMonth :=
MAX ( Time[MonthNumber] )
Since each row in your pivot table will have one month, this will just return that month as a measure so you can use it in later calculations. You could also use SUM(), MIN(), etc. since there's only one value.
RollingAverage :=
CALCULATE (
[Total],
DATESINPERIOD (
Time[PK_Date],
LASTDATE ( Time[PK_Date] ),
-3,
YEAR
),
FILTER (
VALUES ( Time[MonthNumber] ),
Time[MonthNumber] = [ChosenMonth]
)
)
This is why it's important to create intermediate, hidden measures for things like the chosen month, so you can reapply that context on a set of dates where DAX really has no equivalent accommodation.
来源：https://stackoverflow.com/questions/31796171/rolling-moving-average-by-month-over-years