Factors

Work with categorical variables (factors)

We often work with categorical variables, and R coerces them into a special data type called a factor. Factors are augmented integers with levels and labels.

Learning objectives

• Check levels of factors
• Reorder factor levels
• Recode factor labels

Pre-meeting

To prepare for this class meeting, please do the following:

• Read R4DS2 17

Class meeting

• Creating factors and checking levels
• Reordering levels in order of frequency, presence in the vector, or reverse order
• Recoding factor labels
• Collapseing and lumping factor labels
• Slides and Code

Homework after the class meeting

Wrap up this lesson

• Complete the exercises

For next class meeting

• Read R4DS2 18