DZone

One of the most common data analysis operations is looking at how frequently certain kinds of observations appear in a data set.  You can use cross-tabulations, also known as contingency tables, to perform this task.

Here, we show you how to compute cross-tabs easily in Java using the Tablesaw open source (Apache 2) library. Tablesaw is a data-frame and visualization library that supports one and two dimensional cross-tabs. For this, the Table class contains the methods you need.

Source: DZone