Transforming categorical and numeric variables

As covered in the previous chapter, we can use the mutate() function from dplyr to transform existing variables and create new ones. The specific transformation depends on the type of the variable and the resulting shape we would like it to be. For example, we may want to change the value of a categorical variable according to a mapping dictionary, create a new variable based on a combination of filtering conditions of existing variables, or group a numeric variable into different ranges in a new variable. Let us look at these scenarios in turn.

Recoding categorical variables

There are many cases when you would want to recode the values of a variable, such as mapping countries’ short names to the corresponding full names. Let’s create a dummy tibble dataset to illustrate this.

In the following code, we have created a students variable that stores information on age, country, gender, and height. This is a small dummy...