Java TasteException类代码示例

import org.apache.mahout.cf.taste.common.TasteException; //导入依赖的package包/类
public void buildRecommend(String taskName) {
    String itemmodelsPath = RecommendConfig.class.getResource("/").getPath() + "itemmodels.csv";
    HadoopUtil.download(taskName, itemmodelsPath, true);
    try {
        DataModel dataModel = new FileDataModel(new File(itemmodelsPath));
        UserSimilarity similarity = new SpearmanCorrelationSimilarity(dataModel);
        UserNeighborhood userNeighborhood = new ThresholdUserNeighborhood(0.1, similarity, dataModel);
        LongPrimitiveIterator userIDs = dataModel.getUserIDs();
        while (userIDs.hasNext()) {
            Long userID = userIDs.nextLong();
            long[] neighborhoods = userNeighborhood.getUserNeighborhood(userID);
            for (long neighborhood : neighborhoods) {
                double userSimilarity = similarity.userSimilarity(userID, neighborhood);
                System.out.printf("(%s,%s,%f)", userID, neighborhood, userSimilarity);
                System.out.println();
            }
        }
    } catch (TasteException | IOException e) {
        log.error(e);
    }
}
 

import org.apache.mahout.cf.taste.common.TasteException; //导入依赖的package包/类
public void IRState(String taskName) {
    String itemmodelsPath = RecommendConfig.class.getResource("/").getPath() + "itemmodels.csv";
    HadoopUtil.download(taskName, itemmodelsPath, false);
    try {
        DataModel fileDataModel = new FileDataModel(new File(itemmodelsPath));
        RecommenderIRStatsEvaluator irStatsEvaluator = new GenericRecommenderIRStatsEvaluator();
        IRStatistics irStatistics = irStatsEvaluator.evaluate(new RecommenderBuilder() {
            @Override
            public org.apache.mahout.cf.taste.recommender.Recommender buildRecommender(final DataModel dataModel) throws TasteException {
                UserSimilarity userSimilarity = new PearsonCorrelationSimilarity(dataModel);
                UserNeighborhood userNeighborhood = new NearestNUserNeighborhood(5, userSimilarity, dataModel);
                return new GenericUserBasedRecommender(dataModel, userNeighborhood, userSimilarity);
            }
        }, new DataModelBuilder() {
            @Override
            public DataModel buildDataModel(final FastByIDMap<PreferenceArray> fastByIDMap) {
                return new GenericDataModel(fastByIDMap);
            }
        }, fileDataModel, null, 5, GenericRecommenderIRStatsEvaluator.CHOOSE_THRESHOLD, 1.0);
        System.out.println("查准率:" + irStatistics.getPrecision());
        System.out.println("查全率:" + irStatistics.getRecall());
    } catch (TasteException | IOException e) {
        e.printStackTrace();
    }
}
 

import org.apache.mahout.cf.taste.common.TasteException; //导入依赖的package包/类
public static void main(String[] args) throws IOException, TasteException {
	DataModel model  = 
			new FileDataModel(new File("data/ua.base"));
	
	UserSimilarity similarity = 
			new PearsonCorrelationSimilarity(model);
	
	UserNeighborhood neighborhood = 
			new NearestNUserNeighborhood(2, similarity, model);
	
	Recommender recommender = new GenericUserBasedRecommender(
			model, neighborhood, similarity);
	
	List<RecommendedItem> recommendations = recommender.recommend(2, 1);
	
	for (RecommendedItem recommendation : recommendations) {
		logger.info(recommendation.toString());
	}
	
	logger.info("over");
}
 

import org.apache.mahout.cf.taste.common.TasteException; //导入依赖的package包/类
private static void recommend(String ratingsFile, int ... userIds)
    throws TasteException, IOException {
  DataModel model = new FileDataModel(new File(ratingsFile));

  UserSimilarity similarity = new PearsonCorrelationSimilarity(model);

  UserNeighborhood neighborhood =
      new NearestNUserNeighborhood(
          100, similarity, model);

  Recommender recommender =  new GenericUserBasedRecommender(
      model, neighborhood, similarity);

  Recommender cachingRecommender = new CachingRecommender(recommender);

  for(int userId: userIds) {
    System.out.println("UserID " + userId);
    List<RecommendedItem> recommendations =
        cachingRecommender.recommend(userId, 2);
    for(RecommendedItem item: recommendations) {
      System.out.println("  item " + item.getItemID() + " score " + item.getValue());
    }
  }
}
 

import org.apache.mahout.cf.taste.common.TasteException; //导入依赖的package包/类
public static void main(String[] args) throws TasteException, IOException {
	DataModel model = new FileDataModel(new File("data/dataset.csv"));
   	ItemSimilarity similarity = new LogLikelihoodSimilarity(model);
   	//UserNeighborhood neighborhood = new ThresholdUserNeighborhood(0.1, similarity, model);
   	GenericItemBasedRecommender recommender = new GenericItemBasedRecommender(model, similarity);
   	List<RecommendedItem> recommendations = recommender.mostSimilarItems(18, 3);
   	for (RecommendedItem recommendation : recommendations) {
   	  System.out.println(recommendation);
   	}

}
 

import org.apache.mahout.cf.taste.common.TasteException; //导入依赖的package包/类
@Override
protected long readItemIDFromString(String value) {

	if (memIdMigtr == null) {
		memIdMigtr = new ItemMemIDMigrator();
	}

	long retValue = memIdMigtr.toLongID(value);
	if (null == memIdMigtr.toStringID(retValue)) {
		try {
			memIdMigtr.singleInit(value);
		} catch (TasteException e) {
			e.printStackTrace();
		}
	}
	return retValue;
}
 

import org.apache.mahout.cf.taste.common.TasteException; //导入依赖的package包/类
public List<RecommendedItem> recommend(long userId, PreferenceArray preferences) throws TasteException {

		if (userExistsInDataModel(userId)) {
			return recommender.recommend(userId, noItems);
		}
		else {
			PlusAnonymousConcurrentUserDataModel plusModel = (PlusAnonymousConcurrentUserDataModel) recommender.getDataModel();

			// Take an available anonymous user form the poll
			Long anonymousUserID = plusModel.takeAvailableUser();

			// Set temporary preferences
			PreferenceArray tempPrefs = preferences;
			tempPrefs.setUserID(0, anonymousUserID);
			// tempPrefs.setItemID(0, itemID);
			plusModel.setTempPrefs(tempPrefs, anonymousUserID);

			List<RecommendedItem> results = recommender.recommend(anonymousUserID, noItems);

			// Release the user back to the poll
			plusModel.releaseUser(anonymousUserID);

			return results;

		}
	}
 

import org.apache.mahout.cf.taste.common.TasteException; //导入依赖的package包/类
public static void main(String[] args) throws IOException, TasteException {
	RandomUtils.useTestSeed();
	
	final DataModel model = new FileDataModel(new File("data/intro.csv"));
	
	RecommenderIRStatsEvaluator evaluator = 
			new GenericRecommenderIRStatsEvaluator();
	
	RecommenderBuilder recommenderBuilder = new RecommenderBuilder() {
		
		public Recommender buildRecommender(DataModel dataModel) throws TasteException {
			UserSimilarity similarity = new PearsonCorrelationSimilarity(model);
			UserNeighborhood neighborhood = 
					new NearestNUserNeighborhood(2, similarity, model);
			return new GenericUserBasedRecommender(model, neighborhood, similarity);
		}
	};
	
	IRStatistics stats = evaluator.evaluate(recommenderBuilder, null, model, null, 2, 
			GenericRecommenderIRStatsEvaluator.CHOOSE_THRESHOLD, 1.0);
	
	System.out.println(stats.getPrecision());
	System.out.println(stats.getRecall());
}
 

import org.apache.mahout.cf.taste.common.TasteException; //导入依赖的package包/类
private void intializeDelegate() {
    try {
    //iterate over all user ids
    LongPrimitiveIterator it = easyrecDataModelDelegate.getUserIDs();
    FastByIDMap<PreferenceArray> preferences = new FastByIDMap<PreferenceArray>(easyrecDataModelDelegate.getNumUsers());
    FastByIDMap<FastByIDMap<Long>> timestamps = new FastByIDMap<FastByIDMap<Long>>(easyrecDataModelDelegate.getNumUsers());
    while (it.hasNext()) {
        Long userId = it.next();
        //get preferences for each user
        PreferenceArray prefs = easyrecDataModelDelegate.getPreferencesFromUser(userId);
        preferences.put(userId,prefs);
        //get preference times for each user
        FastByIDMap<Long> timestampsForUser = new FastByIDMap<Long>(prefs.getIDs().length);
        for (Long itemId: prefs.getIDs()) {
            timestampsForUser.put(itemId,easyrecDataModelDelegate.getPreferenceTime(userId, itemId));
        }
        timestamps.put(userId, timestampsForUser);
    }
    //generate GenericDataModel
    setMaxPreference(easyrecDataModelDelegate.getMaxPreference());
    setMinPreference(easyrecDataModelDelegate.getMinPreference());
    this.inMemoryDelegate = new GenericDataModel(preferences,timestamps);
    } catch (TasteException e) {
        logger.warn("caught exception while reading preference data", e);
    }
}
 

import org.apache.mahout.cf.taste.common.TasteException; //导入依赖的package包/类
@Override
public LongPrimitiveIterator getItemIDs() throws TasteException {
    FastIDSet itemIDs = new FastIDSet();
    try {
        Query.Builder query = Query.newBuilder();
        query.setLimit(Integer.MAX_VALUE);
        query.addKindBuilder().setName(DEFAULT_IMPRESSIONS_ITEMS_KIND_NAME);
        List<Key> results = runProjectionQuery(query.build(), "getItemIDs()");
        for (Key key : results) {
            itemIDs.add(key.getPathElement(0).getId());
        }
    } catch (DatastoreException e) {
        throw new TasteException(e);
    }
    return itemIDs.iterator();
}
 

import org.apache.mahout.cf.taste.common.TasteException; //导入依赖的package包/类
@Override
public Float getPreferenceValue(long userID, long itemID) throws TasteException {
    try {
        Query.Builder query = Query.newBuilder();
        query.setLimit(Integer.MAX_VALUE);
        query.addKindBuilder().setName(DEFAULT_IMPRESSIONS_KIND_NAME);
        // Filter by userId
        query.setFilter(DatastoreHelper.makeFilter(
                USER_ID_COLUMN,
                PropertyFilter.Operator.EQUAL,
                DatastoreHelper.makeValue(userID)
        ));
        query.setFilter(DatastoreHelper.makeFilter(
                ITEM_ID_COLUMN,
                PropertyFilter.Operator.EQUAL,
                DatastoreHelper.makeValue(userID)
        ));
        List<Entity> results = runQuery(query.build(), "getPreferenceValue()");
        if(results.isEmpty()) {
            return null;
        }
        return 1f; // Boolean/Binary preference values
    } catch (DatastoreException e) {
        throw new TasteException(e);
    }
}
 

import org.apache.mahout.cf.taste.common.TasteException; //导入依赖的package包/类
@Override
public Long getPreferenceTime(long userID, long itemID) throws TasteException {
    try {
        Query.Builder query = Query.newBuilder();
        query.setLimit(Integer.MAX_VALUE);
        query.addKindBuilder().setName(DEFAULT_IMPRESSIONS_KIND_NAME);
        // Filter by userId
        query.setFilter(DatastoreHelper.makeFilter(
                USER_ID_COLUMN,
                PropertyFilter.Operator.EQUAL,
                DatastoreHelper.makeValue(userID)
        ));
        query.setFilter(DatastoreHelper.makeFilter(
                ITEM_ID_COLUMN,
                PropertyFilter.Operator.EQUAL,
                DatastoreHelper.makeValue(userID)
        ));
        List<Entity> results = runQuery(query.build(), "getPreferenceTime()");
        if(results.isEmpty()) {
            return null;
        }
        return DatastoreHelper.getLong(DatastoreHelper.getPropertyMap(results.get(0)).get(TIMESTAMP_COLUMN));
    } catch (DatastoreException e) {
        throw new TasteException(e);
    }
}
 

import org.apache.mahout.cf.taste.common.TasteException; //导入依赖的package包/类
@Override
public int getNumItems() throws TasteException {
    Integer itemCount = itemCountCache.get();
    if (itemCount == null) {
        try {
            Query.Builder query = Query.newBuilder();
            query.addKindBuilder().setName(DEFAULT_IMPRESSIONS_ITEMS_KIND_NAME);
            query.addProjection(PropertyExpression.newBuilder().setProperty(
                    PropertyReference.newBuilder().setName("__key__")));
            List<Key> results = runProjectionQuery(query.build(), "getNumItems()");
            itemCount = results.size();
            itemCountCache.set(itemCount);
        } catch (DatastoreException e) {
            e.printStackTrace();
            throw new TasteException(e);
        }
    }
    return itemCount;
}
 

import org.apache.mahout.cf.taste.common.TasteException; //导入依赖的package包/类
@Override
public int getNumUsers() throws TasteException {
    Integer userCount = userCountCache.get();
    if (userCount == null) {
        try {
            Query.Builder query = Query.newBuilder();
            query.setLimit(Integer.MAX_VALUE);
            query.addKindBuilder().setName(DEFAULT_IMPRESSIONS_USER_KIND_NAME);
            List<Entity> results = runQuery(query.build(), "getNumUsers()");
            userCount = results.size();
            userCountCache.set(userCount);
        } catch (DatastoreException e) {
            throw new TasteException(e);
        }
    }
    return userCount;
}
 

import org.apache.mahout.cf.taste.common.TasteException; //导入依赖的package包/类
@Override
public PreferenceArray get(Long userID) throws TasteException {
    try {
        List<Entity> results = getItemsForUser(userID);
        if(results == null || results.isEmpty()) {
            throw new NoSuchUserException(userID);
        }
        int i = 0;
        PreferenceArray prefs = new GenericUserPreferenceArray(results.size());
        prefs.setUserID(0, userID);
        for (Entity entity : results) {
            prefs.setItemID(
                    i,
                    DatastoreHelper.getLong(
                            DatastoreHelper.getPropertyMap(entity).get(ITEM_ID_COLUMN)
                    )
            );
            prefs.setValue(i, 1f);
            i++;
        }
        return prefs;
    } catch (DatastoreException e) {
        throw new TasteException(e);
    }
}