Using R Programming Structures: Object Systems

IN THIS COURSE

• 1.  Course Overview
  2m 41s
  In this video, you’ll learn more about the course and the instructor. You’ll start by looking at object systems in R. This includes the S3 object system, which is a generic function object-oriented programming system. You’ll see how the S3 object system can be used along with a function. Then you'll move onto the R5 object system, which is commonly known as the system of reference classes. You’ll also create a basic class. FREE ACCESS
• 2.  Recognizing the print() Function & S3 Object System
  10m 7s
  In this video, you’ll watch a demo. This demo is about the S3 object system in R. You’ll begin by initializing a variable. Onscreen you’ll see a variable called date. This is a type called Sys.Date. It holds the current date. Next, you’ll invoke the class function on the date variable and this returns 'Date'. You’ll define a data frame that contains a couple of columns, names, and ages. FREE ACCESS
• 3.  Identifying R Function Invocations in S3
  5m 25s
  In this video, you’ll watch a demo. This demo continues with the S3 object system. You’ll pick up where you left off at the end of the last demo. You’ll continue with the print.Date method. This method is named with the keyword print followed by a dot, followed by the name of the class Date. Note the uppercase D. The generic print function knows it can rely on this method to print Date objects. FREE ACCESS
• 4.  Creating Custom Classes Using R Functions
  6m 45s
  In this video, you’ll watch a demo. In this demo, you’ll continue to explore the S3 object system in R. You’ll define an object of a particular class. Onscreen you’ll see a simple object called human.sofia. This is a list and it contains the two elements, name, and age. You’ll invoke the class function on this variable human.sofia and what you’ll get back is 'list'. FREE ACCESS
• 5.  Extending the print() Function for R Custom Classes
  9m 59s
  In this video, you’ll watch a demo. In this demo, you’ll continue to build on experiments with the S3 object system. You’ll see two classes onscreen. In code cell 27, the class of human.denver is set to be the string "human". You’ve used class as a replacement function. The second method that's visible onscreen now is in code cell 28, where you've used the structure function. FREE ACCESS
• 6.  Using Reference Classes in R
  7m 52s
  In this video, you’ll watch a demo. In this demo, you’ll learn more about the system of Reference Classes. You’ll learn this is a different object-oriented system that’s available in R. You’ll discover S3 originally came from the S programming language. As R became more mainstream and as other methods passing object-oriented paradigms such as those in Java became more popular, R added in a system that’s like the Java object-oriented paradigm. FREE ACCESS
• 7.  Using Member Variables and Functions in R
  8m 45s
  In this video, you’ll watch a demo. In this demo, you’ll continue exploring reference classes in R. Here, you’ll add in some methods. Onscreen you’ll see the setRefClass function has been invoked. The return value from the setRefClass function can be thought of as a class factory. Using this, you’ll get objects of class Account. This is the class template. FREE ACCESS
• 8.  Using Inheritance in Reference Classes in R
  5m 12s
  In this video, you’ll watch a demo. In this demo, you’ll continue to explore reference classes in R. You’ll see how inheritance can be implemented using reference classes. Onscreen, you’ll see a new class StudentAccount which inherits from Account. You’ll see the crucial word here is contains. You’ll see on line 2 of this code cell, "StudentAccount" contains "Account". That's how to tell R that StudentAccount inherits from the Account-based class. FREE ACCESS
• 9.  Course Summary
  1m 49s
  In this video, you’ll summarize what you’ve learned in the course. In this course, you’ve learned  Object Systems in R, and the S3 object system. You learned how to change the class attribute for a list. You also defined a function for print to invoke for custom classes. You delved into the use of the use method function to define functions for custom classes, which other functions can invoke. FREE ACCESS