let freq = [];

let wave = [];

let t = 0;

const N = 4;

const loc = { x: 150, y: 200 };

const dt = 0.05;

​

function setup() {

  createCanvas(600, 400);

  let maxrad = 100;

  let startfreq = 1;

​

  for (let i = 0; i < N; i++) {

    radii.push(maxrad / (2*i + 1));

    freq.push(startfreq * (2*i + 1));

  }

}

​

function draw() {

  background(80);

  translate(loc.x, loc.y);

  stroke(220);

  let x = 0;

  let y = 0;

​

  for (let i = 0; i < N; i++) {

    xold = x;

    yold = y;

    x += radii[i] * cos(freq[i] * t);

    y += radii[i] * sin(freq[i] * t);

​

    fill(220);

    ellipse(x, y, radii[i] / 10);

    line(xold, yold, x, y);

    noFill();

    ellipse(xold, yold, 2 * radii[i]);

  }

  wave.unshift(y);

  translate(200, 0);

  line(x - 200, y, 0, y);

  beginShape();

  for (let i = 0; i < wave.length; i++) {

    vertex(i, wave[i]);

  }

  endShape();

  if(wave.length > 250) {

    wave.pop();

  }

  t += dt;

​

  // if(frameCount == 30) {

  //    noLoop();

  // }

}

​