svn commit: r1000119 - in /mahout/trunk/core/src: main/java/org/apache/mahout/math/stats/OnlineAuc.java test/java/org/apache/mahout/math/stats/OnlineAucTest.java

[tdunning]

Author: tdunning
Date: Wed Sep 22 18:19:00 2010
New Revision: 1000119

URL: http://svn.apache.org/viewvc?rev=1000119&view=rev
Log:
Fixed test error.  Added ability to set window size for averaging.

Modified:
    mahout/trunk/core/src/main/java/org/apache/mahout/math/stats/OnlineAuc.java
    
mahout/trunk/core/src/test/java/org/apache/mahout/math/stats/OnlineAucTest.java

Modified: 
mahout/trunk/core/src/main/java/org/apache/mahout/math/stats/OnlineAuc.java
URL: 
http://svn.apache.org/viewvc/mahout/trunk/core/src/main/java/org/apache/mahout/math/stats/OnlineAuc.java?rev=1000119&r1=1000118&r2=1000119&view=diff
==============================================================================
--- mahout/trunk/core/src/main/java/org/apache/mahout/math/stats/OnlineAuc.java 
(original)
+++ mahout/trunk/core/src/main/java/org/apache/mahout/math/stats/OnlineAuc.java 
Wed Sep 22 18:19:00 2010
@@ -33,7 +33,6 @@ import java.util.Random;
  * on-line.
  */
 public class OnlineAuc {
-
   enum ReplacementPolicy {
     FIFO, FAIR, RANDOM
   }
@@ -43,6 +42,9 @@ public class OnlineAuc {
   // for the FIFO policy
   public static final int HISTORY = 10;
 
+  // defines the exponential averaging window for results
+  private int windowSize=Integer.MAX_VALUE;
+
   // FIFO has distinctly the best properties as a policy.  See OnlineAucTest 
for details
   private ReplacementPolicy policy = ReplacementPolicy.FIFO;
   private transient Random random = 
org.apache.mahout.common.RandomUtils.getRandom();
@@ -102,7 +104,7 @@ public class OnlineAuc {
           m += 0.5;
         }
       }
-      averages.set(category, averages.get(category) + (m / count - 
averages.get(category)) / samples.get(category));
+      averages.set(category, averages.get(category) + (m / count - 
averages.get(category)) / Math.min(windowSize, samples.get(category)));
     }
     return auc();
   }
@@ -115,4 +117,8 @@ public class OnlineAuc {
   public void setPolicy(ReplacementPolicy policy) {
     this.policy = policy;
   }
+
+  public void setWindowSize(int windowSize) {
+    this.windowSize = windowSize;
+  }
 }

Modified: 
mahout/trunk/core/src/test/java/org/apache/mahout/math/stats/OnlineAucTest.java
URL: 
http://svn.apache.org/viewvc/mahout/trunk/core/src/test/java/org/apache/mahout/math/stats/OnlineAucTest.java?rev=1000119&r1=1000118&r2=1000119&view=diff
==============================================================================
--- 
mahout/trunk/core/src/test/java/org/apache/mahout/math/stats/OnlineAucTest.java 
(original)
+++ 
mahout/trunk/core/src/test/java/org/apache/mahout/math/stats/OnlineAucTest.java 
Wed Sep 22 18:19:00 2010
@@ -81,8 +81,8 @@ public final class OnlineAucTest extends
 
     // FAIR policy isn't so accurate
     assertEquals(0.7603, stats[0].getMean(), 0.03);
-    assertEquals(0.7603, stats[0].getQuartile(1), 0.025);
-    assertEquals(0.7603, stats[0].getQuartile(3), 0.025);
+    assertEquals(0.7603, stats[0].getQuartile(1), 0.03);
+    assertEquals(0.7603, stats[0].getQuartile(3), 0.03);
 
     // FIFO policy seems best
     assertEquals(0.7603, stats[1].getMean(), 0.001);