// Daniel Shiffman

// http://natureofcode.com

​

let angle = 0;

let angleVelocity = 0.2;

let amplitude = 100;

​

function setup() {

  createCanvas(640, 240);

}

function draw() {

  background(255);

​

  stroke(0);

  strokeWeight(2);

  fill(127, 127);

​

  for (let x = 0; x <= width; x += 24) {

    // 1) Calculate the y position according to amplitude and sine of the angle.

    let y = amplitude * sin(angle);

    // 2) Draw a circle at the (x,y) position.

    circle(x, y + height / 2, 48);

    // 3) Increment the angle according to angular velocity.

    angle += angleVelocity;

  }

}