svn commit: r935877 - /lucene/mahout/trunk/core/src/main/java/org/apache/mahout/cf/taste/impl/model/PlusAnonymousUserDataModel.java

[srowen]

Author: srowen
Date: Tue Apr 20 11:37:01 2010
New Revision: 935877

URL: http://svn.apache.org/viewvc?rev=935877&view=rev
Log:
Changes for Ch 5 of the book -- handle null prefs

Modified:
    
lucene/mahout/trunk/core/src/main/java/org/apache/mahout/cf/taste/impl/model/PlusAnonymousUserDataModel.java

Modified: 
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=935877&r1=935876&r2=935877&view=diff
==============================================================================
--- 
lucene/mahout/trunk/core/src/main/java/org/apache/mahout/cf/taste/impl/model/PlusAnonymousUserDataModel.java
 (original)
+++ 
lucene/mahout/trunk/core/src/main/java/org/apache/mahout/cf/taste/impl/model/PlusAnonymousUserDataModel.java
 Tue Apr 20 11:37:01 2010
@@ -51,7 +51,7 @@ import org.apache.mahout.cf.taste.model.
  * </p>
  * 
  * <p>
- * But, continue to use <code>realModel</code> as input to other components. 
To recommend, first construct and
+ * But, you may 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.
@@ -66,6 +66,7 @@ import org.apache.mahout.cf.taste.model.
  *   PreferenceArray tempPrefs = ...;
  *   plusModel.setTempPrefs(tempPrefs);
  *   recommender.recommend(PlusAnonymousUserDataModel.TEMP_USER_ID, 10);
+ *   plusModel.setTempPrefs(null);
  * }
  * </pre>
  * 
@@ -87,8 +88,10 @@ public final class PlusAnonymousUserData
   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));
+    if (prefs != null) {
+      for (int i = 0; i < prefs.length(); i++) {
+        this.prefItemIDs.add(prefs.getItemID(i));
+      }
     }
   }