/*
 * LensKit, an open source recommender systems toolkit.
 * Copyright 2010-2013 Regents of the University of Minnesota and contributors
 * Work on LensKit has been funded by the National Science Foundation under
 * grants IIS 05-34939, 08-08692, 08-12148, and 10-17697.
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU Lesser General Public License as
 * published by the Free Software Foundation; either version 2.1 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 org.grouplens.lenskit.knn.item;

import org.grouplens.grapht.annotation.DefaultImplementation;
import org.grouplens.lenskit.knn.item.model.ItemItemModel;
import org.grouplens.lenskit.vectors.MutableSparseVector;
import org.grouplens.lenskit.vectors.SparseVector;

/**
 * Algorithm for scoring items given an item-item model and neighborhood scorer.
 * Used by {@link ItemItemScorer} and {@link ItemItemGlobalScorer} to score items.
 *
 * @author <a href="http://www.grouplens.org">GroupLens Research</a>
 * @since 0.10
 */
@DefaultImplementation(DefaultItemScoreAlgorithm.class)
public interface ItemScoreAlgorithm {
    /**
     * Score items for a user.
     *
     * @param model    The item-item model.
     * @param userData The user's rating data.
     * @param scores   The score vector (key domain is items to score). Unscoreable
     *                 items will be left unchanged.
     * @param scorer   The scorer to use.
     */
    void scoreItems(ItemItemModel model, SparseVector userData,
                    MutableSparseVector scores,
                    NeighborhoodScorer scorer);
}

@@ -1354,19 +1354,16 @@
  scorer.
-%0A *
  Used by
@@ -1365,24 +1365,27 @@
 ed by %7B@link
+%0A *
  ItemItemSco
@@ -1437,16 +1437,172 @@
 e items.
+ This logic is mainly abstracted%0A * so that the personalized and global item scorers can share logic; it isn't very common to%0A * reimplement this component.
 %0A *%0A * @
@@ -1999,16 +1999,30 @@
 coreable
+ items will be
 %0A     * 
@@ -2041,22 +2041,8 @@
     
-items will be 
 left

Improve docs on item score algorithm