// Copyright (C) 2011 Zeno Gantner, Chris Newell
//
// This file is part of MyMediaLite.
//
// MyMediaLite 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 3 of the License, or
// (at your option) any later version.
//
// MyMediaLite 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 MyMediaLite. If not, see <http://www.gnu.org/licenses/>.
package org.mymedialite.data;
import org.mymedialite.datatype.IBooleanMatrix;
/**
* Interface for implicit, positive-only user feedback.
* @version 2.03
*/
public interface IPosOnlyFeedback extends IDataSet {
/**
* By-user access, users are stored in the rows, items in the culumns.
*/
IBooleanMatrix userMatrix();
/**
* By-item access, items are stored in the rows, users in the culumns.
*/
IBooleanMatrix itemMatrix();
/**
* Add a user-item event to the data structure.
* @param userId the user ID
* @param itemId the item ID
*/
void add(int userId, int itemId);
/**
* Get a copy of the item matrix
* @return a copy of the item matrix
*/
IBooleanMatrix getItemMatrixCopy();
/**
* Get a copy of the user matrix
* @return a copy of the user matrix
*/
IBooleanMatrix getUserMatrixCopy();
/**
* Remove a user-item event from the data structure.
* @param userId the user ID
* @param itemId the item ID
*/
void remove(int userId, int itemId);
/**
* Get the transpose of the dataset (users and items exchanged)
* @return the transpose of the dataset
*/
IPosOnlyFeedback transpose();
}