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In R, the function runif() can be used to generate random numbers from a uniform distribution between 0 and 1. Additionally, the sample() function can be used to generate a random sample from a given vector, and the rnorm() function can be used to generate random numbers from a standard normal distribution.
You can use the following methods to generate random numbers in R:
Method 1: Generate One Random Number in Range
#generate one random number between 1 and 20 runif(n=1, min=1, max=20)
Method 2: Generate Multiple Random Numbers in Range
#generate five random numbers between 1 and 20 runif(n=5, min=1, max=20)
Method 3: Generate One Random Integer in Range
#generate one random integer between 1 and 20 sample(1:20, 1)
Method 4: Generate Multiple Random Integers in Range
#generate five random integers between 1 and 20 (sample with replacement) sample(1:20, 5, replace=TRUE) #generate five random integers between 1 and 20 (sample without replacement) sample(1:20, 5, replace=FALSE)
The following examples show how to use each of these methods in practice.
Method 1: Generate One Random Number in Range
The following code shows how to generate one random number between 1 and 20:
#generate one random number between 1 and 20 runif(n=1, min=1, max=20) [1] 8.651919
This function generates 8.651919 as the random number between 1 and 20.
Method 2: Generate Multiple Random Numbers in Range
The following code shows how to generate five random numbers between 1 and 20:
#generate five random numbers between 1 and 20 runif(n=5, min=1, max=20) [1] 12.507360 6.719675 1.836038 17.685829 16.874723
Method 3: Generate One Random Integer in Range
The following code shows how to generate one random integer between 1 and 20:
#generate one random integer between 1 and 20 sample(1:20, 1) [1] 7
This function generates 7 as the random integer between 1 and 20.
Method 4: Generate Multiple Random Integers in Range
The following code shows how to generate five random integers between 1 and 20:
#generate five random integers between 1 and 20 (sample with replacement) sample(1:20, 5, replace=TRUE) [1] 20 13 15 20 5 #generate five random integers between 1 and 20 (sample without replacement) sample(0:20, 5, replace=FALSE) [1] 6 15 5 16 19
Note that if we use replace=TRUE then we allow the same integer to be generated more than once.
However, if we use replace=FALSE then we do not allow the same integer to be generated more than once.
The following tutorials explain how to perform other common tasks in R: