private static double getJaccardBtw2User(User u1, User u2){
		double same = 0.0;
		for (Business business1 : u1.businesses){
			for (Business business2 : u2.businesses){
				if(business1.id.equals(business2.id)){
					double star1 = ubStar.get(u1.u_id + ";" + business1.id);
					double star2 = ubStar.get(u2.u_id + ";" + business2.id);
					if (Math.abs(star1 - star2) <= DELTA){
						same += 1;
					}
				}
			}
		}
		
		int total = u1.businesses.size() + u2.businesses.size();
		return same/total;
	}