Tableau Prep: Up & Running

Chapter 34. Doing Analytical Calculations

When Prep Builder was originally released, it was missing a number of functions that Desktop users were used to. Therefore, part of a Desktop user’s normal analytical process was not straightforward within Prep Builder. Some of these capabilities, known as analytical calculations, are currently being added to the tool.

Analytical calculations actually refers to functions within a calculation. In this chapter, we’ll look at a type of calculation familiar to Desktop users called Table Calculations, how and why to use them in Prep, and some examples and use cases.

What Is a Table Calculation?

Table Calculations in Tableau Desktop are highly flexible and easy to use with a couple of clicks. Table Calculations allow you to handle secondary aggregations, like rank or running total, that would not otherwise be possible in Tableau.

The downside of Table Calculations is exactly the same as what makes them great: their flexibility. A Table Calculation can be easily reconfigured to work on whatever dimensions are within the view. Therefore, whenever a user wants to use the calculation, they need to understand how to reconfigure it. With complicated views, if the user doesn’t reconfigure the calculation correctly, this can impact both the performance of the view and the accuracy of the data output. Taking this work on during the data preparation stage can help mitigate these risks.

For example, let’s use Tableau’s Superstore data set to cover a use ...