// Similarity between Wolf and Pinguin: -0.24019223070763077
// R: cor(c(8,3,1),c(2,10,2)): -0.2401922
System.out.println("Similarity between Wolf and Pinguin: "+pearsonSimilarity.userSimilarity(id2thing.toLongID("Wolf"), id2thing.toLongID("Pinguin")));
GenericUserBasedRecommender recommender = new GenericUserBasedRecommender(model, new NearestNUserNeighborhood(3, pearsonSimilarity, model), pearsonSimilarity);
for(RecommendedItem r : recommender.recommend(id2thing.toLongID("Wolf"), 3)) {
// Pork:
// (0.8196561646738477 * 8 + (-0.6465846072812313) * 1) / (0.8196561646738477 + (-0.6465846072812313)) = 34,15157 ~ 10
// Grass:
// (2*(-0.24019223070763077)+7*(-0.6465846072812313)) / ((-0.24019223070763077) + (-0.6465846072812313)) = 5,65
// Corn: