​

function setup() {

  createCanvas(800, 500);

  fill(255);

  stroke(100);

}

​

function draw() {

  noStroke();

  freq = frameCount * 0.02;

​

  let tanVal = map(tan(freq), -1, 1, -100, 100);

  colors = map(tanVal,-1, 1, 0, 255)

  fill(colors)

​

  x = frameCount;

  ellipse(x, height/2+tanVal, 30, 50);

}