Store Results of Loop in Vector in R (Example) | Save Output of for-Loop in Array

In this R tutorial you’ll learn how to save the output of a for-loop in a vector or array.

The article contains the following contents:

Here’s how to do it.

Example: Saving Output of for-Loop in Vector or Array

In this Example, I’ll show how to store the results of a for-loop in a vector (or array) in R.

We first have to create an empty vector. The following for-loop will produce character outputs, for that reason, we are creating an empty character vector:

my_vec <- character()            # Create empty character vector
my_vec                           # Print vector to RStudio console
# character(0)

The following for-loop contains three parts: A head were we specify the iterations of our loop; A line of code were we are creating some output; And a line of code were we are storing the output in a vector object.

for(i in 1:5) {                  # Head of for-loop
  my_out <- LETTERS[i]           # Create some output
  my_vec <- c(my_vec, my_out)    # Save output in vector
}

Let’s have a look at the final result:

my_vec                           # Show final vector
# "A" "B" "C" "D" "E"

As you can see based on the previous output of the RStudio console, the previous for-loop has created a vector consisting of five character elements. Note that we could apply the same type of R code within a repeat-loop or within a while-loop as well.

Video & Further Resources

Would you like to learn more about vectors and loops? Then you might have a look at the following video of my YouTube channel. I’m showing the examples of this article in the video:

The YouTube video will be added soon.

In addition, you could read some of the other articles on my website.

• Store Results of Loop in List
• Store Results of Loop in Data Frame
• How to Create a Vector of Zero Length
• Append to Vector in Loop
• for-Loop in R
• Loops in R
• The R Programming Language

In summary: You learned in this article how to store loop results in a vector in R. If you have further questions, please tell me about it in the comments section.