Course

Additional

Find the Statistical Mode Write to a File Format Decimal Places

Data Frames

Convert a List to a Dataframe Create an Empty Dataframe Combine Two Dataframe into One Change Column Name of a Dataframe Extract Columns From a Dataframe Drop Columns in a Dataframe Reorder Columns in a Dataframe Split Dataframe Merge Multiple Dataframes Delete Rows From Dataframe Make a List of Dataframes

Introduction

"Hello World" Program Add Two Vectors Find Sum, Mean and Product of Vector in R Programming Take Input From User Generate Random Number from Standard Distributions Sample from a Population Find Minimum and Maximum Sort a Vector

Strings

Concatenate Two Strings Find the Length of a String Check if Characters are Present in a String Extract n Characters From a String Replace Characters in a String Compare two Strings Convert Factors to Characters Trim Leading and Trailing Whitespaces

Vectors

Concatenate a Vector of Strings Check if a Vector Contains the Given Element Count the Number of Elements in a Vector Find Index of an Element in a Vector Access Values in a Vector Add Leading Zeros to Vector

Decision and Loops

Find the Factorial of a Number R Multiplication Table Check Prime Number check Armstrong Number Print the Fibonacci Sequence Check for Leap Year Check if a Number is Odd or Even in R Programming Check if a Number is Positive, Negative or Zero Find the Sum of Natural Numbers

Functions

Convert Decimal into Binary using Recursion in R Find the Factorial of a Number Using Recursion Find the Factors of a Number Fibonacci Sequence Using Recursion in R Find H.C.F. or G.C.D.Find L.C.M.Make a Simple Calculator Sum of Natural Numbers Using Recursion

Fibonacci Sequence Using Recursion in R

The first two terms of the Fibonacci sequence is 0 followed by 1. All other terms are obtained by adding the preceding two terms.

This means to say the nth term is the sum of (n-1)th and (n-2)th term.


              
The Fibonacci sequence: 0, 1, 1, 2, 3, 5, 8, 13, 21

Example: Fibonacci Sequence in R


              
# Program to diplay the Fibonacci
# sequence up to n-th term using
# recursive functions

recurse_fibonacci <- function(n) {
    if(n <= 1) {
        return(n)
    } else {
        return(recurse_fibonacci(n-1) + recurse_fibonacci(n-2))
    }
}

# take input from the user
nterms = as.integer(readline(prompt="How many terms? "))

# check if the number of terms is valid
if(nterms <= 0) {
    print("Plese enter a positive integer")
} else {
    print("Fibonacci sequence:")
    for(i in 0:(nterms-1)) {
        print(recurse_fibonacci(i))
    }
}

Output


              
How many terms? 9
[1] "Fibonacci sequence:"
[1] 0
[1] 1
[1] 1
[1] 2
[1] 3
[1] 5
[1] 8
[1] 13
[1] 21

Here, we ask the user for the number of terms in the sequence.

A recursive function recurse_fibonacci() is used to calculate the nth term of the sequence. We use a for loop to iterate and calculate each term recursively.

See this page to find out how you can print fibonacci series in R without using recursion.