What fields/data types are you utilizing when you use this feature? Normally, you need to work with:
- Two numeric fields (two measures)
- A measure and a date
Here you go.
Your "Month" is a string - which won't work with Trendlines. I converted the combination of Download Month + "/1/" + Download Year to a true date and then used that instead.
RL_Forum.twbx.zip 82.0 KB
Unfortunately I am not able to open Tableau versions beyond version 6.0.
Would you be able to save it as an older version?
Very sorry, the oldest version I have installed is 6.1
Create a new calculation called "My Date":
Date(str([Download Month]) + "/1/" + str([Download Year]))
On the Columns shelf, replace Download Month with "My Date". On the Columns shelf, click the My Date pill and change it from Discrete (blue colored) to Continuous (Green colored). On the Columns Shelf, click the My Date pill again, and change it's datepart to Month.
Right click inside the viz, and choose Trendlines | AGG(<Some Measure>)
You should be good to go.
I just changed the original SQL query to bring back the 'Download Month' as an integer and then converted the pill to Continuous and it seemed to work.
However, the trend lines are only displaying per column, not across the whole diagram as I thought it would.