You can use one of the following methods to convert a list to a vector in R:
#use unlist() function new_vector names = FALSE) #use flatten_*() function from purrr library new_vector
The following examples show how to use each of these methods in practice with the following list:
#create list
my_list #display list
my_list
$A
[1] 1 2 3
$B
[1] 4 5
$C
[1] 6
Example 1: Convert List to Vector Using unlist() Function
The following code shows how to convert a list to a vector using the unlist() function:
#convert list to vector
new_vector #display vector
new_vector
A1 A2 A3 B1 B2 C
1 2 3 4 5 6
Note that you can specify use.names = FALSE to remove the names from the vector:
#convert list to vector new_vector names = FALSE) #display vector new_vector [1] 1 2 3 4 5 6
Example 2: Convert List to Vector Using flatten_* Function
The following code shows how to convert a list to a vector using the family of flatten_* functions from the purrr package:
library(purrr) #convert list to vector new_vector #display vector new_vector [1] 1 2 3 4 5 6
The flatten_dbl() function specifically converts the list to a vector of type double.
Note that we could use flatten_chr() to convert a character list to a vector of type character:
library(purrr)
#define character list
my_char_list
#convert character list to character vector
new_char_vector #display vector
new_char_vector
[1] "a" "b" "c" "d" "e" "f"
Check out this page for a complete list of the family of flatten_* functions.
Note: If you’re working with an extremely large list, the flatten_* functions will perform quicker than the unlist() function from base R.
Additional Resources
How to Convert List to a Data Frame in R
How to Convert Matrix to Vector in R
How to Convert Data Frame Column to Vector in R