text: let pos_x;
  let pos_y;
  let point_width = 1;
  let max_pos_mvt = 1;
  
  function setup() {
      // createCanvas( windowWidth, windowHeight );
      createCanvas( windowWidth, 600 );
      background(255);
  
      // specify initial position to be center of canvas
      pos_x = width * 0.5;
      pos_y = height * 0.5;
  }
  
  function draw() {
  
      // draw the pos
      ellipse(pos_x, pos_y, point_width);
  
      // we want to randomly update the position of the pos
      pos_x += floor(random(-max_pos_mvt, max_pos_mvt + 1));
      pos_y += floor(random(-max_pos_mvt, max_pos_mvt + 1));
  }
  