i usually have January values missing in the database due to the nature of our business - i can calculate the trailing 12 months sales accurately in table form, but it is not correct in the graph. The missing january value is skipped and tableau uses only existing values to calculate the trailing 12 months sales.
|Year-Month||SALES||Trailing 12 month sum of sales|
the trailing 12 month chart below is missing the Jan 2016 point and starts with Feb16 which is incorrect - it should be $2.050 vs $2.316. it is using the previous existing 12 values (Feb15 to Feb16) instead of 12 months (Mar15 to Feb16).
i read something about padded values but i can't get it to work.
thank you in advance.
I see you are trying to pad data. Will this data be an average or something else? You might want to review this article on the topic - padding | Drawing with Numbers to get started.
Please let us know how its going.