Course Content

R Introduction: Part II

1. Matrices

What is a Matrix?matrix() Function Transposing Matrix Indexation Namings Operation with Matrices Sales and Revenue

2. Data Frames

What is a Data Frame?data.frame() Function Columns Accessors Logical Indexing Manipulating Columns Manipulating Rows Data Extraction

3. Lists

What is a List?Namings Extracting List Elements Modifying

Modifying

Now let's move on to list modification tools. First, let's consider methods of adding an element (or elements) to a list.

The first method is convenient for adding single values. You need to assign a new value to the new index or naming. For example, let's add a new element named integer with the value of 23L.


              12345
            
# Creating a list
test <- list(text = "Text", number = 42, logical = TRUE)
# Add new value
test['integer'] <- 23L
test # Output modified list

Note
Unlike in the list() function, you must use quotes for naming while adding a new element. You can also 'merge' two lists by placing them inside a vector. This approach will 'connect' two lists together.


              123456
            
# Two lists
list1 <- list("first", 10)
list2 <- list("second", 20)
# Merge two lists
list12 <- c(list1, list2)
list12 # Output its value

Also, you can delete elements from the list. To do it, assign to the necessary index value NULL. For example, let's remove TRUE from the first example.


              123456
            
test <- list(text = "Text", number = 42, logical = TRUE)
test['integer'] <- 23L
# Remove the third element
test$logical <- NULL
# Output modified list
test

As you can see, you removed the TRUE element. Finally, to change the existing value of the list, reassign the new value to the existing index/naming. For example, if you write test[1] <- "word", then instead of "Text", the first element will be "word".

Task

Given list info from the previous chapter. Your tasks are:

Rewrite the fourth element to 44 (this chapter is the 44th).
Remove the third element (which is 1).
Add a new element named Level with the value of 'Beginner'.
Output modified list info.

Switch to desktop for real-world practiceContinue from where you are using one of the options below

Everything was clear?

Thanks for your feedback!

Section 3. Chapter 4

Modifying

Now let's move on to list modification tools. First, let's consider methods of adding an element (or elements) to a list.

The first method is convenient for adding single values. You need to assign a new value to the new index or naming. For example, let's add a new element named integer with the value of 23L.


              12345
            
# Creating a list
test <- list(text = "Text", number = 42, logical = TRUE)
# Add new value
test['integer'] <- 23L
test # Output modified list

Note
Unlike in the list() function, you must use quotes for naming while adding a new element. You can also 'merge' two lists by placing them inside a vector. This approach will 'connect' two lists together.


              123456
            
# Two lists
list1 <- list("first", 10)
list2 <- list("second", 20)
# Merge two lists
list12 <- c(list1, list2)
list12 # Output its value

Also, you can delete elements from the list. To do it, assign to the necessary index value NULL. For example, let's remove TRUE from the first example.


              123456
            
test <- list(text = "Text", number = 42, logical = TRUE)
test['integer'] <- 23L
# Remove the third element
test$logical <- NULL
# Output modified list
test

Task

Given list info from the previous chapter. Your tasks are:

Rewrite the fourth element to 44 (this chapter is the 44th).
Remove the third element (which is 1).
Add a new element named Level with the value of 'Beginner'.
Output modified list info.

Switch to desktop for real-world practiceContinue from where you are using one of the options below

Everything was clear?

Thanks for your feedback!

Section 3. Chapter 4

Modifying

Now let's move on to list modification tools. First, let's consider methods of adding an element (or elements) to a list.

The first method is convenient for adding single values. You need to assign a new value to the new index or naming. For example, let's add a new element named integer with the value of 23L.


              12345
            
# Creating a list
test <- list(text = "Text", number = 42, logical = TRUE)
# Add new value
test['integer'] <- 23L
test # Output modified list

Note
Unlike in the list() function, you must use quotes for naming while adding a new element. You can also 'merge' two lists by placing them inside a vector. This approach will 'connect' two lists together.


              123456
            
# Two lists
list1 <- list("first", 10)
list2 <- list("second", 20)
# Merge two lists
list12 <- c(list1, list2)
list12 # Output its value

Also, you can delete elements from the list. To do it, assign to the necessary index value NULL. For example, let's remove TRUE from the first example.


              123456
            
test <- list(text = "Text", number = 42, logical = TRUE)
test['integer'] <- 23L
# Remove the third element
test$logical <- NULL
# Output modified list
test

Task

Given list info from the previous chapter. Your tasks are:

Rewrite the fourth element to 44 (this chapter is the 44th).
Remove the third element (which is 1).
Add a new element named Level with the value of 'Beginner'.
Output modified list info.

Switch to desktop for real-world practiceContinue from where you are using one of the options below

Everything was clear?

Thanks for your feedback!

Now let's move on to list modification tools. First, let's consider methods of adding an element (or elements) to a list.

The first method is convenient for adding single values. You need to assign a new value to the new index or naming. For example, let's add a new element named integer with the value of 23L.


              12345
            
# Creating a list
test <- list(text = "Text", number = 42, logical = TRUE)
# Add new value
test['integer'] <- 23L
test # Output modified list

Note
Unlike in the list() function, you must use quotes for naming while adding a new element. You can also 'merge' two lists by placing them inside a vector. This approach will 'connect' two lists together.


              123456
            
# Two lists
list1 <- list("first", 10)
list2 <- list("second", 20)
# Merge two lists
list12 <- c(list1, list2)
list12 # Output its value

Also, you can delete elements from the list. To do it, assign to the necessary index value NULL. For example, let's remove TRUE from the first example.


              123456
            
test <- list(text = "Text", number = 42, logical = TRUE)
test['integer'] <- 23L
# Remove the third element
test$logical <- NULL
# Output modified list
test

Task

Given list info from the previous chapter. Your tasks are:

Rewrite the fourth element to 44 (this chapter is the 44th).
Remove the third element (which is 1).
Add a new element named Level with the value of 'Beginner'.
Output modified list info.

Switch to desktop for real-world practiceContinue from where you are using one of the options below

Section 3. Chapter 4

Switch to desktop for real-world practiceContinue from where you are using one of the options below