I have been working on a dashboard for some time now and the community here has been very helpful with many of the elements I struggled with during its development. I've "almost" got it done and am at the last part where I'd like to plot a dynamically calculated reference line based on a parameter
What I'm trying to do is create a dashboard where my users can view store performance over time. I intially setup a crosstab which would show store metrics per quarter filtered by Product Category. The Metric would change based on a measure select parameter which I got help from here: (http://community.tableau.com/thread/119557)
Its primarily a parameter that would "pick" a measure to represent.
We then wanted to look at visual trending. this is where I created a line graph over time for each store using the same parameter to select the measure.
My users then wanted a "Category" average to see how the store performed against other stores irrespective of any of the other filter selections. So to do this (after some reading) I made a second connection to the same data source. I tied the category filter to this new worksheet but no other filter. I then used some table calcs within a modified metric parameter (with help from the community: (http://community.tableau.com/thread/122895) along with a very helpful article from Johnathan D (http://drawingwithnumbers.artisart.org/customizing-grand-totals-part-2/) to create average calculations at the Grand total level.
(This is where I'm sure experts might have an easier way to acomplish this, but the numbers worked so I..."went with it")
And we are now where I'm at
What I was hoping to do was plot the values that I arrived at with the average calculations on the trending line graph I had.
I attempted to use a built in average line graph function (which I left in the packaged workbook) and it works well for all the metrics that use average. However because I have one metric that uses Median (Delivery) the built in "average" numbers on the chart don't match up to my calculated median average number.
So I guess after my long winded explanation, my question is. Can I plot a custom reference line that changes based on the selected customized grand total metric value that I arrived at in my average calculations?
If so, How?
Once again, thank you everyone for the help!
Custom Reference Line.twbx.zip 513.0 KB