Access elements in a list
Subsetting a list is similar to subsetting a vector or data frame, with one extra useful operation.
To access the elements in the list, use [ ]. This will always return another list.
my_list[1]
$my_words
[1] "I <3 R"
my_list[c(1,2)]
$my_words
[1] "I <3 R"
$my_numbers
[1] 42 24
To pull out the data inside each element of your list, use [[ ]].
my_list[[1]]
[1] "I <3 R"
If your list is named, you can use the $ operator: my_list$my_words. This is the same as using [[ ]] to return the inner data.
This is a part of the course
“Introduction to R for Finance”
Exercise instructions
- The
portfolionamed list is available for use. - Access the second and third elements of
portfoliousing[ ]andc(). - Use
$to access thecorrelationdata.
Hands-on interactive exercise
Have a go at this exercise by completing this sample code.
# Second and third elements of portfolio
# Use $ to get the correlation data
This exercise is part of the course
Introduction to R for Finance
Learn essential data structures such as lists and data frames and apply that knowledge directly to financial examples.
Wouldn't it be nice if there was a way to hold related vectors, matrices, or data frames together in R? In this final chapter, you will explore lists and many of their interesting features by building a small portfolio of stocks.
Exercise 1: What is a list?Exercise 2: Create a listExercise 3: Named listsExercise 4: Access elements in a listExercise 5: Adding to a listExercise 6: Removing from a listExercise 7: A few list creating functionsExercise 8: Split itExercise 9: Split-Apply-CombineExercise 10: AttributesExercise 11: Congratulations!What is DataCamp?
Learn the data skills you need online at your own pace—from non-coding essentials to data science and machine learning.