Chapter 2 Data Matrix

In the previous chapter we talked about the standard notion of data from the statistical learning perspective, that is, as a “set of individuals described by one or more variables”. In addition, we looked at various types of data tables, and we also discussed about the distinction between raw tables and clean tables. In this chapter, we make the transition from a data table to a data matrix. I will introduce some notation used in the rest of the book, and focus on how to think of a data table in terms of a matrix, and what aspects to keep in mind while converting any data table into a mathematical matrix.