public static Map<Integer, Map<Integer, Pearson>> getAllPearson(UserPreferences[] UP, double minPearson) {
		Map<Integer, Map<Integer, Pearson>> pearsons = new TreeMap<Integer, Map<Integer, Pearson>>();
		for (int i = 0; i < UP.length; i++) {
			for (int j = i + 1; j < UP.length; j++) {
				Pearson p = new Pearson(UP[i], UP[j]);
				if (p.pearson >= minPearson || p.pearson <= (-minPearson)) {
					Map<Integer, Pearson> map;
					if (pearsons.containsKey(p.userId1)) {
						map = pearsons.get(p.userId1);
					} else {
						map = new TreeMap<Integer, Pearson>();
						pearsons.put(p.userId1, map);
					}
					map.put(p.userId2, p);
				}
			}
		}
		return pearsons;
	}