Part II

Data Processing

Chapter 6 Data Assembly

Chapter 7 Data Normalization

Chapter 8 Groupby Operations: Split-Apply-Combine

Now that we know the basics of working with our data, we can go into more detail on how to process it. Data does not always come in one part. We begin with combining multiple data sets, by either concatenating it together or joining them by values (Chapter 6). Combining data is usually something we do in the tidying process (Chapter 4), but normalizing data is the process of splitting it up into separate parts. It seems counterintuitive to split data up, but this is something that is typically done for data storage, especially for databases (Chapter 7). Finally, we go into more detail into grouped operations (Chapter 8) that were first introduced in Chapter 1.