Defining a new S4 class

You have seen that the S3 class does not have any formal definition, and as a result, there is a greater chance of making naïve mistakes. The S4 class is more rigorous, and it has a formal definition and a uniform way to create objects. In this recipe, you will define a new S4 class robustSummary.

Getting ready

Suppose you have a numeric vector x representing the number of hours spent on social media in a week. You want to define a new S4 class that will display the robust descriptive statistics. The name of the new class will be robustSummary, and the individual items of this class will be as follows:

• Median
• MAD
• First quartile
• Third quartile

Here is the original vector with 50 numeric values...