svn commit: r988126 - /mahout/trunk/utils/src/main/java/org/apache/mahout/utils/nlp/collocations/llr/CollocCombiner.java

[drew]

Author: drew
Date: Mon Aug 23 14:09:59 2010
New Revision: 988126

URL: http://svn.apache.org/viewvc?rev=988126&view=rev
Log:
MAHOUT-486: Null Pointer Exception running DictionaryVectorizer with ngram=2 on 
Reuters dataset

Modified:
    
mahout/trunk/utils/src/main/java/org/apache/mahout/utils/nlp/collocations/llr/CollocCombiner.java

Modified: 
mahout/trunk/utils/src/main/java/org/apache/mahout/utils/nlp/collocations/llr/CollocCombiner.java
URL: 
http://svn.apache.org/viewvc/mahout/trunk/utils/src/main/java/org/apache/mahout/utils/nlp/collocations/llr/CollocCombiner.java?rev=988126&r1=988125&r2=988126&view=diff
==============================================================================
--- 
mahout/trunk/utils/src/main/java/org/apache/mahout/utils/nlp/collocations/llr/CollocCombiner.java
 (original)
+++ 
mahout/trunk/utils/src/main/java/org/apache/mahout/utils/nlp/collocations/llr/CollocCombiner.java
 Mon Aug 23 14:09:59 2010
@@ -18,6 +18,7 @@
 package org.apache.mahout.utils.nlp.collocations.llr;
 
 import java.io.IOException;
+import java.util.Iterator;
 
 import org.apache.hadoop.mapreduce.Reducer;
 
@@ -28,16 +29,19 @@ public class CollocCombiner extends Redu
   protected void reduce(GramKey key, Iterable<Gram> values, Context context) 
throws IOException, InterruptedException {
 
     int freq = 0;
-
-    // accumulate frequencies from values.
-    for (Gram gramValue : values) {
-      freq += gramValue.getFrequency();
+    Gram value = null;
+    
+    // accumulate frequencies from values, preserve the last value
+    // to write to the context.
+    for (Iterator<Gram> it = values.iterator(); it.hasNext(); ) {
+      value = it.next();
+      freq += value.getFrequency();
     }
 
-    Gram sum = new Gram();
-    sum.setFrequency(freq);
-
-    context.write(key, sum);
+    if (value != null) {
+      value.setFrequency(freq);
+      context.write(key, value);
+    }
   }
 
 }