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Posted to commits@mahout.apache.org by sr...@apache.org on 2009/08/27 14:58:52 UTC
svn commit: r808405 - in /lucene/mahout/trunk/core/src:
main/java/org/apache/mahout/cf/taste/impl/model/
test/java/org/apache/mahout/cf/taste/impl/recommender/
Author: srowen
Date: Thu Aug 27 12:58:52 2009
New Revision: 808405
URL: http://svn.apache.org/viewvc?rev=808405&view=rev
Log:
Added "plus anonymous user" decorators to enable anonymous user recommendations. Also snuck in a fix to a unit test.
Added:
lucene/mahout/trunk/core/src/main/java/org/apache/mahout/cf/taste/impl/model/PlusAnonymousUserDataModel.java
lucene/mahout/trunk/core/src/main/java/org/apache/mahout/cf/taste/impl/model/PlusAnonymousUserLongPrimitiveIterator.java
Modified:
lucene/mahout/trunk/core/src/test/java/org/apache/mahout/cf/taste/impl/recommender/GenericItemBasedRecommenderTest.java
Added: lucene/mahout/trunk/core/src/main/java/org/apache/mahout/cf/taste/impl/model/PlusAnonymousUserDataModel.java
URL: http://svn.apache.org/viewvc/lucene/mahout/trunk/core/src/main/java/org/apache/mahout/cf/taste/impl/model/PlusAnonymousUserDataModel.java?rev=808405&view=auto
==============================================================================
--- lucene/mahout/trunk/core/src/main/java/org/apache/mahout/cf/taste/impl/model/PlusAnonymousUserDataModel.java (added)
+++ lucene/mahout/trunk/core/src/main/java/org/apache/mahout/cf/taste/impl/model/PlusAnonymousUserDataModel.java Thu Aug 27 12:58:52 2009
@@ -0,0 +1,198 @@
+/**
+ * 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.impl.model;
+
+import org.apache.mahout.cf.taste.common.Refreshable;
+import org.apache.mahout.cf.taste.common.TasteException;
+import org.apache.mahout.cf.taste.impl.common.FastIDSet;
+import org.apache.mahout.cf.taste.impl.common.LongPrimitiveIterator;
+import org.apache.mahout.cf.taste.model.DataModel;
+import org.apache.mahout.cf.taste.model.PreferenceArray;
+
+import java.util.Collection;
+
+/**
+ * <p>This {@link DataModel} decorator class is useful in a situation where you wish to recommend
+ * to a user that doesn't really exist yet in your actual {@link DataModel}. For example maybe you
+ * wish to recommend DVDs to a user who has browsed a few titles on your DVD store site, but, the
+ * user is not yet registered.</p>
+ *
+ * <p>This enables you to temporarily add a temporary user to an existing {@link DataModel} in a way
+ * that recommenders can then produce recommendations anyway. To do so, wrap your real implementation
+ * in this class:</p>
+ *
+ * <p><pre>
+ * DataModel realModel = ...;
+ * DataModel plusModel = new PlusAnonymousUserDataModel(realModel);
+ * ...
+ * ItemSimilarity similarity = new LogLikelihoodSimilarity(realModel); // not plusModel
+ * </pre></p>
+ *
+ * <p>But, continue to use <code>realModel</code> as input to other components.
+ * To recommend, first construct and
+ * set the temporary user information on the model and then simply call the recommender.
+ * The <code>synchronized</code> block exists to remind you that this is of course not
+ * thread-safe. Only one set of temp data can be inserted into the model and used at one
+ * time.</p>
+ *
+ * <p><pre>
+ * Recommender recommender = ...;
+ * ...
+ * synchronized(...) {
+ * PreferenceArray tempPrefs = ...;
+ * plusModel.setTempPrefs(tempPrefs);
+ * recommender.recommend(PlusAnonymousUserDataModel.TEMP_USER_ID, 10);
+ * }
+ * </pre></p>
+ */
+public final class PlusAnonymousUserDataModel implements DataModel {
+
+ public static final long TEMP_USER_ID = Long.MIN_VALUE;
+
+ private final DataModel delegate;
+ private PreferenceArray tempPrefs;
+ private final FastIDSet prefItemIDs;
+
+ public PlusAnonymousUserDataModel(DataModel delegate) {
+ this.delegate = delegate;
+ this.prefItemIDs = new FastIDSet();
+ }
+
+ public void setTempPrefs(PreferenceArray prefs) {
+ this.tempPrefs = prefs;
+ this.prefItemIDs.clear();
+ for (int i = 0; i < prefs.length(); i++) {
+ this.prefItemIDs.add(prefs.getItemID(i));
+ }
+ }
+
+ @Override
+ public LongPrimitiveIterator getUserIDs() throws TasteException {
+ return new PlusAnonymousUserLongPrimitiveIterator(delegate.getUserIDs(), TEMP_USER_ID);
+ }
+
+ @Override
+ public PreferenceArray getPreferencesFromUser(long userID) throws TasteException {
+ if (userID == TEMP_USER_ID) {
+ return tempPrefs;
+ } else {
+ return delegate.getPreferencesFromUser(userID);
+ }
+ }
+
+ @Override
+ public FastIDSet getItemIDsFromUser(long userID) throws TasteException {
+ if (userID == TEMP_USER_ID) {
+ return prefItemIDs;
+ } else {
+ return delegate.getItemIDsFromUser(userID);
+ }
+ }
+
+ @Override
+ public LongPrimitiveIterator getItemIDs() throws TasteException {
+ return delegate.getItemIDs();
+ // Yeah ignoring items that only the plus-one user knows about... can't really happen
+ }
+
+ @Override
+ public PreferenceArray getPreferencesForItem(long itemID) throws TasteException {
+ PreferenceArray delegatePrefs = delegate.getPreferencesForItem(itemID);
+ for (int i = 0; i < tempPrefs.length(); i++) {
+ if (tempPrefs.getItemID(i) == itemID) {
+ int length = delegatePrefs.length();
+ PreferenceArray newPreferenceArray = new GenericItemPreferenceArray(length + 1);
+ for (int j = 0; j < length; j++) {
+ newPreferenceArray.set(j, delegatePrefs.get(j));
+ }
+ newPreferenceArray.set(length, tempPrefs.get(i));
+ newPreferenceArray.sortByUser();
+ return newPreferenceArray;
+ }
+ }
+ return delegatePrefs;
+ }
+
+ @Override
+ public Float getPreferenceValue(long userID, long itemID) throws TasteException {
+ if (userID == TEMP_USER_ID) {
+ for (int i = 0; i < tempPrefs.length(); i++) {
+ if (tempPrefs.getItemID(i) == itemID) {
+ return tempPrefs.getValue(i);
+ }
+ }
+ return null;
+ } else {
+ return delegate.getPreferenceValue(userID, itemID);
+ }
+ }
+
+ @Override
+ public int getNumItems() throws TasteException {
+ return delegate.getNumItems();
+ }
+
+ @Override
+ public int getNumUsers() throws TasteException {
+ return delegate.getNumUsers() + 1;
+ }
+
+ @Override
+ public int getNumUsersWithPreferenceFor(long... itemIDs) throws TasteException {
+ boolean hasAll = true;
+ for (long itemID : itemIDs) {
+ boolean found = false;
+ for (int i = 0; i < tempPrefs.length(); i++) {
+ if (tempPrefs.getItemID(i) == itemID) {
+ found = true;
+ break;
+ }
+ }
+ if (!found) {
+ hasAll = false;
+ break;
+ }
+ }
+ return delegate.getNumUsersWithPreferenceFor(itemIDs) + (hasAll ? 1 : 0);
+ }
+
+ @Override
+ public void setPreference(long userID, long itemID, float value) throws TasteException {
+ if (userID == TEMP_USER_ID) {
+ throw new UnsupportedOperationException();
+ } else {
+ delegate.setPreference(userID, itemID, value);
+ }
+ }
+
+ @Override
+ public void removePreference(long userID, long itemID) throws TasteException {
+ if (userID == TEMP_USER_ID) {
+ throw new UnsupportedOperationException();
+ } else {
+ delegate.removePreference(userID, itemID);
+ }
+ }
+
+ @Override
+ public void refresh(Collection<Refreshable> alreadyRefreshed) {
+ delegate.refresh(alreadyRefreshed);
+ }
+
+}
+
Added: lucene/mahout/trunk/core/src/main/java/org/apache/mahout/cf/taste/impl/model/PlusAnonymousUserLongPrimitiveIterator.java
URL: http://svn.apache.org/viewvc/lucene/mahout/trunk/core/src/main/java/org/apache/mahout/cf/taste/impl/model/PlusAnonymousUserLongPrimitiveIterator.java?rev=808405&view=auto
==============================================================================
--- lucene/mahout/trunk/core/src/main/java/org/apache/mahout/cf/taste/impl/model/PlusAnonymousUserLongPrimitiveIterator.java (added)
+++ lucene/mahout/trunk/core/src/main/java/org/apache/mahout/cf/taste/impl/model/PlusAnonymousUserLongPrimitiveIterator.java Thu Aug 27 12:58:52 2009
@@ -0,0 +1,87 @@
+/**
+ * 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.impl.model;
+
+import org.apache.mahout.cf.taste.impl.common.LongPrimitiveIterator;
+
+final class PlusAnonymousUserLongPrimitiveIterator implements LongPrimitiveIterator {
+
+ private final LongPrimitiveIterator delegate;
+ private final long extraDatum;
+ private boolean datumConsumed;
+
+ PlusAnonymousUserLongPrimitiveIterator(LongPrimitiveIterator delegate, long extraDatum) {
+ this.delegate = delegate;
+ this.extraDatum = extraDatum;
+ datumConsumed = false;
+ }
+
+ @Override
+ public long nextLong() {
+ if (datumConsumed) {
+ return delegate.nextLong();
+ } else {
+ if (delegate.hasNext()) {
+ long delegateNext = delegate.peek();
+ if (extraDatum <= delegateNext) {
+ datumConsumed = true;
+ return extraDatum;
+ } else {
+ return delegate.next();
+ }
+ } else {
+ datumConsumed = true;
+ return extraDatum;
+ }
+ }
+ }
+
+ @Override
+ public long peek() {
+ if (datumConsumed) {
+ return delegate.peek();
+ } else {
+ if (delegate.hasNext()) {
+ long delegateNext = delegate.peek();
+ if (extraDatum <= delegateNext) {
+ return extraDatum;
+ } else {
+ return delegateNext;
+ }
+ } else {
+ return extraDatum;
+ }
+ }
+ }
+
+ @Override
+ public boolean hasNext() {
+ return !datumConsumed || delegate.hasNext();
+ }
+
+ @Override
+ public Long next() {
+ return nextLong();
+ }
+
+ @Override
+ public void remove() {
+ throw new UnsupportedOperationException();
+ }
+
+}
Modified: lucene/mahout/trunk/core/src/test/java/org/apache/mahout/cf/taste/impl/recommender/GenericItemBasedRecommenderTest.java
URL: http://svn.apache.org/viewvc/lucene/mahout/trunk/core/src/test/java/org/apache/mahout/cf/taste/impl/recommender/GenericItemBasedRecommenderTest.java?rev=808405&r1=808404&r2=808405&view=diff
==============================================================================
--- lucene/mahout/trunk/core/src/test/java/org/apache/mahout/cf/taste/impl/recommender/GenericItemBasedRecommenderTest.java (original)
+++ lucene/mahout/trunk/core/src/test/java/org/apache/mahout/cf/taste/impl/recommender/GenericItemBasedRecommenderTest.java Thu Aug 27 12:58:52 2009
@@ -42,6 +42,7 @@
assertEquals(0.18, firstRecommended.getValue(), EPSILON);
recommender.refresh(null);
recommended = recommender.recommend(1, 1);
+ firstRecommended = recommended.get(0);
assertEquals(2, firstRecommended.getItemID());
assertEquals(0.18, firstRecommended.getValue(), EPSILON);
}
@@ -116,7 +117,8 @@
}
/**
- * Contributed test case that verifies fix for bug <a href="http://sourceforge.net/tracker/index.php?func=detail&aid=1396128&group_id=138771&atid=741665">
+ * Contributed test case that verifies fix for bug
+ * <a href="http://sourceforge.net/tracker/index.php?func=detail&aid=1396128&group_id=138771&atid=741665">
* 1396128</a>.
*/
public void testBestRating() throws Exception {