動かないんですけど、どこが間違っていますか？

mySketch
xxxxxxxxxx
 
let vecLocation = [];
let vecVelocity = [];
const NUM = 2000;
​
function setup() {
  createCanvas(windowWidth, windowHeight);
  frameRate(60);
  for (let i = 0; i < NUM; i++) {
    vecLocation[i] = createVector(width/2, height/2);
    vecVelocity[i] = createVector(random(-10, 10), random(-10, 10));
  }
}
​
function draw() {
  background(0);
  noStroke();
  fill(random(255),random(255),random(255),random(255));
  for (let i = 0; i < NUM; i++) {
    ellipse(vecLocation[i].x,vecLocation[i].y,20,20);
    vecLocation[i].add(vecVelocity[i]);
    if(vecLocation[i].x > width || vecLocation[i].x < 0) { 
      vecVelocity[i].x = vecVelocity[i].x * -1;
    }
    if(vecLocation[i].y > height || vecLocation[i].y < 0) { 
      vecVelocity[i].y = vecVelocity[i].y * -1;
    }
  }
}