// Daniel Shiffman

// http://natureofcode.com

​

function setup() {

  createCanvas(640, 240);

}

​

function draw() {

  background(255);

​

  let period = 120;

  let amplitude = 200;

​

  // Calculating horizontal position according to formula for simple harmonic motion

  let x = amplitude * sin((TWO_PI * frameCount) / period);

​

  stroke(0);

  strokeWeight(2);

  fill(127);

  translate(width / 2, height / 2);

  line(0, 0, x, 0);

  circle(x, 0, 48);

}

​