This is a lightweight and fast library that provides a basic implementation of Binet's Formula to calculate Fibonacci numbers using the golden ratio. Please keep in mind that this function may be prone to floating-point JavaScript imprecision.

• 📘 Comes with built-in TypeScript definitions
• 🚀 Lightweight and fast
• 👴 Compliant with ECMAScript 3

• function binetFormula(n: number): number;

  Calculates the Fibonacci number at the given position using Binet's Formula.

  Binet's Formula is an efficient way to calculate Fibonacci numbers using the golden ratio.

  Keep in mind this function may be prone to floating-point JavaScript imprecision.

  Name	Type	Description	Optional?
  n	number	The positive integer position in the Fibonacci sequence to look for.	No

  Throws a TypeError if n is not a number, negative, or not an integer. Returns the Fibonacci number at position n.

import binet = require('@santi100/binet-formula'); // TypeScript
import binet from '@santi100/binet-formula'; // ESM
const binet = require('@santi100/binet-formula'); // CJS

// Example usage of the binet function
const fibonacciNumber = binet(5); // Calculate the Fibonacci number at position 5
console.log(fibonacciNumber); // Output: Approximately 5

Feel free to use this library to calculate Fibonacci numbers efficiently using Binet's Formula. The implementation supports various module systems, including TypeScript and CommonJS.

If you're curious, Binet's Formula is: $$ F_n = \frac{\varphi^n - \frac{1}{(-\varphi)^n}}{\sqrt{5}} $$