You can use one of the following methods to create a matrix with random numbers in R:

**Method 1: Create Matrix with Random Values in Range**

#create matrix of 10 random values between 1 and 20 random_matrix <- matrix(runif(n=10, min=1, max=20), nrow=5)

**Method 2: Create Matrix with Random Integers in Range**

#create matrix of 10 random integers between 1 and 20 random_matrix <- matrix(round(runif(n=10, min=1, max=20), 0), nrow=5)

The following examples show how to use each of these methods in practice.

**Method 1: Create Matrix with Random Values in Range**

The following code shows how to create a matrix with 5 rows consisting of 10 random values between 1 and 20:

#make this example reproducible set.seed(1) #create matrix with 10 random numbers between 1 and 20 random_matrix <- matrix(runif(n=10, min=1, max=20), nrow=5) #view matrix random_matrix [,1] [,2] [1,] 6.044665 18.069404 [2,] 8.070354 18.948830 [3,] 11.884214 13.555158 [4,] 18.255948 12.953167 [5,] 4.831957 2.173939

The result is a matrix with 5 rows and 2 columns, where each value in the matrix is between 1 and 20.

**Method 2: Create Matrix with Random Integers in Range**

The following code shows how to create a matrix of 10 random integers between 1 and 50:

#make this example reproducible set.seed(1) #create matrix with 10 random integers between 1 and 50 random_matrix <- matrix(round(runif(n=10, min=1, max=50), 0), nrow=5) #view matrix random_matrix [,1] [,2] [1,] 14 45 [2,] 19 47 [3,] 29 33 [4,] 46 32 [5,] 11 4

The result is a matrix with 5 rows and 2 columns, where each value in the matrix is an integer between 1 and 50.

Note that the **runif()** function generates random numbers, *including* the **min** and **max** values.

For example, it’s possible that the matrix above could have included both 1 and 50.

Also note that it’s possible for the same number to appear multiple times in the matrix when using this method.

**Additional Resources**

The following tutorials explain how to perform other common tasks in R:

How to Create a Vector with Random Numbers in R

How to Select Random Samples in R