Ask that same question on Jonathan's website (drawingwithnumbers) and I'm sure he'll respond.
Excel has the idea of worksheet as data, so one worksheet can reference another worksheet's data by a worksheet reference like Sheet2!A2:. In Tableau, there's a data source, and the worksheets are each independent views of that data source. We don't have the ability to use the computational results of one worksheet as a data source for another worksheet, though there's an idea for that: http://community.tableau.com/ideas/1604.
So you have a few options:
- Increase the level of detail on the desired worksheet to include everything to make your original table calculation work. Adjust that table calculation's Compute Using settings to deal with the increased level of detail, then set up additional table calculations to get your desired measures. This can be tricky and won't necessarily meet your performance needs, but can be entirely done in Tableau.
- Generate your table calc results, export them to a crosstab or .mdb file, and then reimport them. This gives you a static output. It can start making troubles if you have more than a few hundred thousand records, because JET can have problems exporting that much data.
- "Push" some set of your computations down into SQL so what now requires table calcs can be done via a regular aggregates (then you can use table calcs for the further computations, or have the original table calc done in SQL. This can be the most work and give you the highest performance.
Depending on the specific project constraints, I've used all three techniques.
Jonathan and Shawn,
Thank you both for responding. The first and third options sound most promising.
Could you go into option one in more detail... What do you mean add additional table calculations?
I am looking to pull the overall weighted averages that are computed from table calucations from three worksheets in tableau into one bar chart... Each worksheet uses a seperate data source- but they can all be linked.