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In R, an empty vector can be created using the vector() function. This function takes any existing vector as an argument and returns a new vector of the same length, but with all values set to NULL. This is a useful tool for quickly creating a space to store data, such as when preparing to read data from a file. Examples of how to use this function are included in this article.
You can use one of the following methods to create an empty vector in R:
#create empty vector with length zero and no specific class empty_vec <- vector() #create empty vector with length zero and a specific class empty_vec <- character() #create empty vector with specific length empty_vec <- rep(NA, times=10)
The following examples show how to use each of these methods in practice.
Method 1: Create Empty Vector with Length Zero
The following code shows how to create a vector with a length of zero and no specific class:
#create empty vector with length zero and no specific class empty_vec <- vector() #display length of vector length(empty_vec) [1] 0
We can then fill the vector with values if we’d like:
#add values 1 through 10 to empty vector empty_vec <- c(empty_vec, 1:10) #view updated vector empty_vec [1] 1 2 3 4 5 6 7 8 9 10
Method 2: Create Empty Vector of Specific Class
The following code shows how to create empty vectors of specific classes:
#create empty vector of class 'character'
empty_vec <- character()
class(empty_vec)
[1] "character"
#create empty vector of class 'numeric'
empty_vec <- numeric()
class(empty_vec)
numeric(0)
#create empty vector of class 'logical'
empty_vec <- logical()
class(empty_vec)
logical(0)
Method 3: Create Empty Vector with Specific Length
The following code shows how to create a vector with a specific length in R:
#create empty vector with length 10 empty_vec <- rep(NA, times=10) #display empty vector empty_vec [1] NA NA NA NA NA NA NA NA NA NA
If you know the length of the vector at the outset, this is the most memory-efficient solution in R.