Programming Skills for Data Science: Start Writing Code to Wrangle, Analyze, and Visualize Data with R, First Edition

12Reshaping Data with tidyr

One of the most common data wrangling challenges is adjusting how exactly row and columns are used to represent your data. Structuring (or restructuring) data frames to have the desired shape can be the most difficult part of creating a visualization, running a statistical model, or implementing a machine learning algorithm.

This chapter describes how you can use the tidyr (“tidy-er”) package to effectively transform your data into an appropriate shape for analysis and visualization.

12.1 What Is “Tidy” Data?

When wrangling data into a data frame for your analysis, you need to decide on the desired structure of that data frame. You need to determine what each row and column will represent, so that you can consistently ...