Exercise

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.

Instructions

100 XP
  • The portfolio named list is available for use.
  • Access the second and third elements of portfolio using [ ] and c().
  • Use $ to access the correlation data.