Show average values on a chart with fixed X axis

[msuser48]

I have the following dataset:

PersonId	FirstLetterReceivedDate	LetterReceivedDate	LetterStopDate	Letters	Y/N
1	01-01-2015	01-01-2015	01-01-2018	1	Yes
1	01-01-2015	01-01-2016	01-01-2018	2	Yes
1	01-01-2015	05-03-2017	01-01-2018	3	No
2	01-12-2017	01-12-2017	05-05-2018	1	No
2	01-12-2017	03-12-2017	05-05-2018	4	No
2	01-12-2017	04-12-2018	05-05-2018	5	Yes
3	01-12-2018	01-12-2018	25-06-2020	1	No
3	01-12-2018	01-12-2019	25-06-2020	6	Yes
3	01-12-2018	25-12-2019	25-06-2020	8	No

The dataset shows 3 different personIds and..:

- when they received their first letter (FirstLetterReceivedDate)

- when they received each letter (LetterReceivedDate)

- when they should stop receiving letters (LetterStopDate)

What i want to do:

Problem 1)

With a slicer filter that uses FirstLetterReceivedDate, I want to show on a line chart the average number of letters received per personId since FirstLetterReceivedDate. The line chart's X axis should be fixed to 4 years, so it looks something like this:

Example:

If i set the date slicer to dates between for example 01-01-2015 and 01-12-2018, we know that..:

- PersonId 1 received 2 letters in year 0-1 after their FirstLetterReceivedDate, and 2 letters from year 0-2.

- PersonId 2 received 4 letters in year 0-1 after their FirstLetterReceivedDate, and 5 letters from year 0-2.

- PersonId 3 received 6 letters in year 0-1 after their FirstLetterReceivedDate, and 8 letters from year 0-2.

So, the average for year 0-1 is 4 letters, and the average for year 0-2 is 5 letters. year 3 would be 0 letters.

Problem 2):

If the date period selected from the slicer is only 1 year (for example 2016-01-01 to 2017-01-01), then the line chart should should drill down on months 0-12 instead of years 1-4.

How to accomplish this complexity?

[amitchandak · Accepted solution]

@msuser48 , You can create an new column like this and use

Year Diff =
var _diff = datediff( [FirstLetterReceivedDate],[LetterReceived],month)/12
return
Switch(True(),
_diff <=1, " 0- 1",
_diff <=2, " 1- 2",
_diff <=3, " 3- 4",
"GT 3"
)