Richie CottonSenior Data Evangelist, DataCamp · Ask me about data and AI upskilling

R Tutorial: Assigning Classes

Name: R Tutorial: Assigning Classes
Uploaded: 2020-03-14T11:13:18+00:00
Duration: 1 min 59 s
Channel: Richie Cotton
Description: In this instructional segment, Richard Cotton explains how the R class() function can be used not only to query an object's class but also to override…

14 Mar 2020 · 2 min

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1:59

In this instructional segment, Richard Cotton explains how the R class() function can be used not only to query an object's class but also to override it. He creates a numeric vector of random exponential numbers, assigns it a new class attribute called "random numbers," and shows that the object's displayed class changes while its underlying type remains numeric. Cotton highlights that typeof cannot be overridden, making the object retain an implicit numeric class. He demonstrates that standard functions such as is.numeric, length, and mean continue to operate correctly despite the altered class attribute, confirming that existing functionality is preserved. The segment concludes with a preview that Chapter 2 will explore leveraging custom classes, emphasizing that class overriding can be done without reinventing core R behavior.

Chapters

Previously you saw the use of the class function to return the class of Samar objects. The class function also has a second use to override the class of an object. For example, you can take a numeric vector, in this case some random numbers from the exponential distribution and then override the class to random numbers. Lets see what the X variable looks like. Now the values of x are the same, but now X shows that it has an attribute named class with the value random numbers. Calling the class function on x like you did before, that is without assignment, returns the value. Notice that the class of X doesn't tell us that X is numeric anymore. However, if you use TypeOf, the value is still the same. In fact, you can't override typeof. This is a fundamental property of an R object. Because of this, X is said to have an implicit class of numeric. In practice, the best way to check that X is still a number would be to use the is numeric function. This function is smart enough to know that regardless of how the class value has changed, the variable still contains numbers. Similarly, the length function returns the correct value. Here we have 10 numbers. Likewise, the mean function still calculates the mean of x correctly. In chapter two, you're going to see how to take advantage of being able to specify the class of an object. But for now, the important takeaways are that you can override the class and that it's possible to do this without having to reinvent existing functionality. Everything continues to work as you need.