Java tutorial
//Copyright (C) 2014 Xin Liu // //RecMe: a lightweight recommendation algorithm library // //RecMe is free software; you can redistribute it and/or //modify it under the terms of the GNU General Public License //as published by the Free Software Foundation; either version 2 //of the License, or (at your option) any later version. // //This program is distributed in the hope that it will be useful, //but WITHOUT ANY WARRANTY; without even the implied warranty of //MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the //GNU General Public License for more details. // //You should have received a copy of the GNU General Public License //along with this program; if not, write to the Free Software //Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. package ch.epfl.lsir.xin.test; import java.io.File; import java.io.IOException; import java.io.PrintWriter; import java.text.SimpleDateFormat; import java.util.ArrayList; import java.util.Date; import java.util.HashMap; import java.util.Random; import org.apache.commons.configuration.ConfigurationException; import org.apache.commons.configuration.PropertiesConfiguration; import ch.epfl.lsir.xin.algorithm.baseline.ItemAverage; import ch.epfl.lsir.xin.algorithm.baseline.UserAverage; import ch.epfl.lsir.xin.datatype.RatingMatrix; import ch.epfl.lsir.xin.io.DataLoaderFile; import ch.epfl.lsir.xin.model.DataSetNumeric; import ch.epfl.lsir.xin.model.NumericRating; import ch.epfl.lsir.xin.util.TrainTestSplitter; public class ItemAverageTest { /** * @param args */ public static void main(String[] args) throws Exception { // TODO Auto-generated method stub PrintWriter logger = new PrintWriter(".//results//ItemAverage"); PropertiesConfiguration config = new PropertiesConfiguration(); config.setFile(new File(".//conf//ItemAverage.properties")); try { config.load(); } catch (ConfigurationException e) { // TODO Auto-generated catch block e.printStackTrace(); } logger.println(new SimpleDateFormat("yyyy-MM-dd HH:mm:ss").format(new Date()) + " Read rating data..."); DataLoaderFile loader = new DataLoaderFile(".//data//MoveLens100k.txt"); loader.readSimple(); DataSetNumeric dataset = loader.getDataset(); System.out.println("Number of ratings: " + dataset.getRatings().size() + " Number of users: " + dataset.getUserIDs().size() + " Number of items: " + dataset.getItemIDs().size()); logger.println("Number of ratings: " + dataset.getRatings().size() + ", Number of users: " + dataset.getUserIDs().size() + ", Number of items: " + dataset.getItemIDs().size()); logger.flush(); double totalMAE = 0; double totalRMSE = 0; int F = 5; logger.println(F + "- folder cross validation."); ArrayList<ArrayList<NumericRating>> folders = new ArrayList<ArrayList<NumericRating>>(); for (int i = 0; i < F; i++) { folders.add(new ArrayList<NumericRating>()); } while (dataset.getRatings().size() > 0) { int index = new Random().nextInt(dataset.getRatings().size()); int r = new Random().nextInt(F); folders.get(r).add(dataset.getRatings().get(index)); dataset.getRatings().remove(index); } for (int folder = 1; folder <= F; folder++) { logger.println("Folder: " + folder); logger.flush(); System.out.println("Folder: " + folder); ArrayList<NumericRating> trainRatings = new ArrayList<NumericRating>(); ArrayList<NumericRating> testRatings = new ArrayList<NumericRating>(); for (int i = 0; i < folders.size(); i++) { if (i == folder - 1)//test data { testRatings.addAll(folders.get(i)); } else {//training data trainRatings.addAll(folders.get(i)); } } //create rating matrix HashMap<String, Integer> userIDIndexMapping = new HashMap<String, Integer>(); HashMap<String, Integer> itemIDIndexMapping = new HashMap<String, Integer>(); for (int i = 0; i < dataset.getUserIDs().size(); i++) { userIDIndexMapping.put(dataset.getUserIDs().get(i), i); } for (int i = 0; i < dataset.getItemIDs().size(); i++) { itemIDIndexMapping.put(dataset.getItemIDs().get(i), i); } RatingMatrix trainRatingMatrix = new RatingMatrix(dataset.getUserIDs().size(), dataset.getItemIDs().size()); for (int i = 0; i < trainRatings.size(); i++) { trainRatingMatrix.set(userIDIndexMapping.get(trainRatings.get(i).getUserID()), itemIDIndexMapping.get(trainRatings.get(i).getItemID()), trainRatings.get(i).getValue()); } trainRatingMatrix.calculateGlobalAverage(); RatingMatrix testRatingMatrix = new RatingMatrix(dataset.getUserIDs().size(), dataset.getItemIDs().size()); for (int i = 0; i < testRatings.size(); i++) { testRatingMatrix.set(userIDIndexMapping.get(testRatings.get(i).getUserID()), itemIDIndexMapping.get(testRatings.get(i).getItemID()), testRatings.get(i).getValue()); } System.out.println("Training: " + trainRatingMatrix.getTotalRatingNumber() + " vs Test: " + testRatingMatrix.getTotalRatingNumber()); logger.println("Initialize a recommendation model based on item average method."); ItemAverage algo = new ItemAverage(trainRatingMatrix); algo.setLogger(logger); algo.build(); algo.saveModel(".//localModels//" + config.getString("NAME")); logger.println("Save the model."); logger.flush(); System.out.println(trainRatings.size() + " vs. " + testRatings.size()); double RMSE = 0; double MAE = 0; int count = 0; for (int i = 0; i < testRatings.size(); i++) { NumericRating rating = testRatings.get(i); double prediction = algo.predict(userIDIndexMapping.get(rating.getUserID()), itemIDIndexMapping.get(rating.getItemID())); if (Double.isNaN(prediction)) { System.out.println("no prediction"); continue; } MAE = MAE + Math.abs(rating.getValue() - prediction); RMSE = RMSE + Math.pow((rating.getValue() - prediction), 2); count++; } MAE = MAE / count; RMSE = Math.sqrt(RMSE / count); logger.println(new SimpleDateFormat("yyyy-MM-dd HH:mm:ss").format(new Date()) + " MAE: " + MAE + " RMSE: " + RMSE); logger.flush(); // System.out.println("MAE: " + MAE + " RMSE: " + RMSE); totalMAE = totalMAE + MAE; totalRMSE = totalRMSE + RMSE; } System.out.println("MAE: " + totalMAE / F + " RMSE: " + totalRMSE / F); logger.println(new SimpleDateFormat("yyyy-MM-dd HH:mm:ss").format(new Date()) + " Final results: MAE: " + totalMAE / F + " RMSE: " + totalRMSE / F); logger.flush(); //MAE: 0.8173633324758338 RMSE: 1.0251973503888645 (MovieLens 100K) } }