/**
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You under the Apache License, Version 2.0
* (the "License"); you may not use this file except in compliance with
* the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.apache.mahout.cf.taste.recommender;
import org.apache.mahout.cf.taste.common.TasteException;
import org.apache.mahout.common.LongPair;
/**
* <p>
* Interface implemented by "user-based" recommenders.
* </p>
*/
public interface UserBasedRecommender extends Recommender {
/**
* @param userID
* ID of user for which to find most similar other users
* @param howMany
* desired number of most similar users to find
* @return users most similar to the given user
* @throws TasteException
* if an error occurs while accessing the {@link org.apache.mahout.cf.taste.model.DataModel}
*/
long[] mostSimilarUserIDs(long userID, int howMany) throws TasteException;
/**
* @param userID
* ID of user for which to find most similar other users
* @param howMany
* desired number of most similar users to find
* @param rescorer
* {@link Rescorer} which can adjust user-user similarity estimates used to determine most similar
* users
* @return IDs of users most similar to the given user
* @throws TasteException
* if an error occurs while accessing the {@link org.apache.mahout.cf.taste.model.DataModel}
*/
long[] mostSimilarUserIDs(long userID, int howMany, Rescorer<LongPair> rescorer) throws TasteException;
}