R Program to find the factorial of a number using a recursion

How to find the factorial of a number using a recursion

Here we are explaining how to write an R program to find the factorial of a number using a recursive function. Give the required number as an argument to the recursive function. 

The factorial of a number is the product of all the integers from 1 to the number.

For example, the factorial of 5 (denoted as 6!) as

1 * 2 * 3 * 4 * 5  = 120

How factorial calculation is implemented in R Program

Given below are the steps which are used in the R program to find the factorial of a number using recursion. In this R program, we give the number directly to the function recur_factorial(). Check if the given number is greater than 1 if yes call the function recur_factorial() to compute the product upto that number.

ALGORITHM

STEP 1: Call function recur_factorial()

STEP 2: Pass the number whose factorial needs to be found as num.

STEP 3: check if the given number is greater than 1

STEP 4:if yes num is multiplied to the factorial of (num – 1 )

STEP 5: Continue until the num reaches 1

R Source Code

                                          recur_factorial <- function(num) {
if(num <= 1) {
return(1)
} else { 
return(num * recur_factorial(num-1))
}
}
recur_factorial(5)
                                      

OUTPUT

[1] 120