Function dft

contents/cooley_tukey/code/javascript/fft.js:3–15

(x)

const Complex = require("complex.js");

function dft(x) {
  const N = x.length;

  // Initialize an array with N elements, filled with 0s
  return Array(N)
    .fill(new Complex(0, 0))
    .map((temp, i) => {
      // Reduce x into the sum of x_k * exp(-2*sqrt(-1)*pi*i*k/N)
      return x.reduce((a, b, k) => {
        return a.add(b.mul(new Complex(0, (-2 * Math.PI * i * k) / N).exp()));
      }, new Complex(0, 0)); // Start accumulating from 0
    });
}

function cooley_tukey(x) {
  const N = x.length;