R Program to Generate Fibonacci Sequence

Introduction

The Fibonacci sequence is a series of numbers where each number is the sum of the two preceding ones, usually starting with 0 and 1. This guide will walk you through writing an R program that generates the Fibonacci sequence up to a specified number of terms.

Problem Statement

Create an R program that:

• Prompts the user to enter the number of terms for the Fibonacci sequence.
• Generates the Fibonacci sequence up to the specified number of terms.
• Displays the generated sequence.

Example:

• Input: 7
• Output: 0, 1, 1, 2, 3, 5, 8

Solution Steps

1. Read the Number of Terms: Use the readline() function to take the number of terms as input from the user.
2. Convert the Input to Numeric: Convert the input from a character string to a numeric value using the as.numeric() function.
3. Initialize the Sequence: Start the sequence with the first two terms, 0 and 1.
4. Generate the Sequence: Use a loop to generate the remaining terms of the sequence.
5. Display the Sequence: Use the print() function to display the generated Fibonacci sequence.

R Program

# R Program to Generate Fibonacci Sequence
# Author: https://www.javaguides.net/

# Step 1: Read the number of terms from the user
n_terms <- as.numeric(readline(prompt = "Enter the number of terms: "))

# Step 2: Initialize the first two terms of the Fibonacci sequence
fib_sequence <- numeric(n_terms)
fib_sequence[1] <- 0

if (n_terms > 1) {
  fib_sequence[2] <- 1

  # Step 3: Generate the Fibonacci sequence
  for (i in 3:n_terms) {
    fib_sequence[i] <- fib_sequence[i - 1] + fib_sequence[i - 2]
  }
}

# Step 4: Display the Fibonacci sequence
print(paste("Fibonacci sequence up to", n_terms, "terms:"))
print(fib_sequence)

Explanation

Step 1: Read the Number of Terms

• The readline() function prompts the user to enter the number of terms. The input is read as a string, so it is converted to a numeric value using as.numeric().

Step 2: Initialize the First Two Terms

• The Fibonacci sequence starts with 0 and 1, so these values are assigned to the first two elements of the fib_sequence vector.

Step 3: Generate the Fibonacci Sequence

• If the number of terms is greater than 2, a loop is used to generate the remaining terms of the sequence. Each new term is the sum of the two preceding ones.

Step 4: Display the Fibonacci Sequence

• The print() function is used to display the entire Fibonacci sequence up to the specified number of terms.

Output Example

Example:

Enter the number of terms: 7
[1] "Fibonacci sequence up to 7 terms:"
[1] 0 1 1 2 3 5 8

Conclusion

This R program demonstrates how to generate a Fibonacci sequence for a given number of terms. It covers basic programming concepts such as loops, user input, and sequence generation, making it a useful example for beginners learning R programming.