Creating Calculations to Enhance Your Data
Each new paradigm gives us the opportunity to “see” phenomena that were before as invisible to us as the colors of the sunset to the fog.
BENJAMIN AND ROSAMUND ZANDER1
Tableau provides two ways to enhance your data through the creation of new fields that don't exist in your datasource. Tableau also allows you to turn single-purpose dashboards and views into multi-purpose analysis environments though parameter controls. Parameters are formula variables that can be used to provide filter-like controls that allow users to change the measures and dimensions used in a dashboard or worksheet.
In this chapter you will learn how to use calculated values and table calculations to derive facts and dimensions that don't exist in your source data. Tableau's Formula Editing window will be explained as well as the Quick Table Calculation menu, and how to modify Quick Table defaults to address your specific needs.
In the sections at the end of the chapter on parameters, you will learn parameter controls—basic and advanced—so that you can make views that address different needs using the same basic visual design.
Tableau makes formula creation as easy as it can possibly be, but it helps to understand the concept of aggregation, and the functions and operators that are available to use before you start making formulas. For those of you that want to dive deeply into Tableau's functions, Appendix A provides in-depth coverage of every Tableau function, ...