Objects in R
In this lesson, you’ll learn some formal definitions and vocabulary for objects in R.
When you are finished, you should be able to…
Identify the structure of an object
Identify the data type(s) of an object.
Understand the required and optional arguments in a function.
Troubleshoot common error messages
Time Estimates: 
Videos: 40 min 
Readings: 15 min 
Activities: 5 min 
Check-ins: 2 Types and Structures
Required Video: Intro to Object Types and Structures
Optional Reading: More Detail on Object Types and Structures
Check-In 1: Data Structures
This lecture did not mention the important structure of data frames.
That’s because, in essence, a data frame is simply a special list - with a few extra restrictions on the list format.
Think about the datasets you have already worked with. Which of the following restrictions on lists do you think are needed for the list to be a data frame?
- The elements of the list must all be vectors of the same length.
- The elements of the list must all be the same data type.
- The elements of the list must all have no missing values.
- The elements of the list must all have names.
Functions
Required Video: Intro to Functions
Required Reading: Basics of R
Check-In 2: Troubleshooting
What is the reason for the error below? How would you fix it?
matrix(c("a", "b", "c", "d"), num_row = 2)## Error in matrix(c("a", "b", "c", "d"), num_row = 2): unused argument (num_row = 2)