Dot[] dots = new Dot[8];
PVector attractor_pos;

void setup() {
  frameRate(60);
  size(800, 800);
  background(0);
  stroke(255);
  smooth();

  initialize();
}

class Dot {
   private PVector pos, vel, acc;

  public Dot(float pos_x, float pos_y, float vel_x, float vel_y) {
    this.pos = new PVector(pos_x, pos_y);
    this.vel = new PVector(vel_x, vel_y);
    this.acc = new PVector(0,0);
  }

  public void move() {
  this.pos.add(this.vel);
  this.vel.add(this.acc);

  //private PVector dist = this.pos.sub(attractor_pos);

  //this.acc.add(
  }

  public void draw() {
  fill(255);
  ellipse(this.pos.x, this.pos.y, 4, 4);
  }
}

public void initialize() {
    attractor_pos = new PVector(width/2, height/2);
  for (int i = 0; i < dots.length; i++) {
  dots[i] = (new Dot(random(width), random(height), random(-0.5, 0.5), random(-0.5, 0.5)));
  }
}

void draw() {
for (int i = 0; i < dots.length; i++) {
 Dot p = dots[i];
 p.draw();
 p.move();
}
}