Summary

In this chapter, numbers were on display. The R language is great for dealing with numbers, since the software was created as a statistical tool. As we know, statistics is all about numbers, so we were able to see that many of the functions used during this chapter are from the Base R, eliminating the need to install or load any library to work with so many useful functions.

We started the chapter by learning about structures with numbers, such as vectors, matrices, and data frames. That knowledge prepared us for the next section, where we studied many operations to deal with numbers in vectors and data frames, and we learned a good resource for that is the apply family of functions.

We also went over how descriptive statistics are important to help us gain an understanding of data and its distribution, because that can drive our efforts of data wrangling before modeling.

Finally, we saw the correlation test and how to interpret its result.