The preceding exercise, Reproducing native Tableau functionality in R, was designed to get you started using R in Tableau. But of course there's no reason in a real-world scenario to access the R engine to reproduce functionality that is native to Tableau. As shown in the architecture screenshot represented in the The Architecture section, calling the R engine adds an extra process which could potentially slow performance.
The next exercise demonstrates a correlation functionality that is not natively available in Tableau. As of this writing, correlation is currently available in the 10.1 beta but this does not necessarily mean that the official 10.1 release will include such functionality.
A correlation is a ...
