2 Working with Data

Statistics is based on the study of data. Without data, all we can do is make guesses. In this chapter, we will learn how to work with data in R. Specifically, how to load data into R so we can work with it, and how to explore our data by calculating summaries and plotting simple figures.

Learning Objectives

  • Learn to load data into R.
  • Learn to explore a dataset using numerical summaries.
  • Learn to explore a dataset using simple plots.

Useful Functions

  • Use read_csv() or the Import Dataset button to load data into R.

  • Use getwd() and setwd() to get and set R’s working directory.

  • Use head() and tail() to examine the beginning and end of a dataset.
  • Use the $ operator to access a particular column of a dataset.
  • Use sort() to sort data.

  • Use length(), mean(), median(), range(), var(), sd(), and table() to calculate numerical summaries.

  • Use barplot() to make a bar plot.
  • Use hist() to make a histogram.

  • Use boxplot() to make a box plot.