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Posted to commits@mahout.apache.org by sr...@apache.org on 2008/07/04 16:25:17 UTC
svn commit: r674067 -
/lucene/mahout/trunk/core/src/main/java/org/apache/mahout/cf/taste/impl/correlation/AbstractCorrelation.java
Author: srowen
Date: Fri Jul 4 07:25:17 2008
New Revision: 674067
URL: http://svn.apache.org/viewvc?rev=674067&view=rev
Log:
Math simplifications from turati -- thanks
Modified:
lucene/mahout/trunk/core/src/main/java/org/apache/mahout/cf/taste/impl/correlation/AbstractCorrelation.java
Modified: lucene/mahout/trunk/core/src/main/java/org/apache/mahout/cf/taste/impl/correlation/AbstractCorrelation.java
URL: http://svn.apache.org/viewvc/lucene/mahout/trunk/core/src/main/java/org/apache/mahout/cf/taste/impl/correlation/AbstractCorrelation.java?rev=674067&r1=674066&r2=674067&view=diff
==============================================================================
--- lucene/mahout/trunk/core/src/main/java/org/apache/mahout/cf/taste/impl/correlation/AbstractCorrelation.java (original)
+++ lucene/mahout/trunk/core/src/main/java/org/apache/mahout/cf/taste/impl/correlation/AbstractCorrelation.java Fri Jul 4 07:25:17 2008
@@ -218,9 +218,12 @@
double n = (double) count;
double meanX = sumX / n;
double meanY = sumY / n;
- double centeredSumXY = sumXY - meanY * sumX - meanX * sumY + n * meanX * meanY;
- double centeredSumX2 = sumX2 - 2.0 * meanX * sumX + n * meanX * meanX;
- double centeredSumY2 = sumY2 - 2.0 * meanY * sumY + n * meanY * meanY;
+ // double centeredSumXY = sumXY - meanY * sumX - meanX * sumY + n * meanX * meanY;
+ double centeredSumXY = sumXY - meanY * sumX;
+ // double centeredSumX2 = sumX2 - 2.0 * meanX * sumX + n * meanX * meanX;
+ double centeredSumX2 = sumX2 - meanX * sumX;
+ // double centeredSumY2 = sumY2 - 2.0 * meanY * sumY + n * meanY * meanY;
+ double centeredSumY2 = sumY2 - meanY * sumY;
double result = computeResult(count, centeredSumXY, centeredSumX2, centeredSumY2, sumXYdiff2);
@@ -303,9 +306,12 @@
double n = (double) count;
double meanX = sumX / n;
double meanY = sumY / n;
- double centeredSumXY = sumXY - meanY * sumX - meanX * sumY + n * meanX * meanY;
- double centeredSumX2 = sumX2 - 2.0 * meanX * sumX + n * meanX * meanX;
- double centeredSumY2 = sumY2 - 2.0 * meanY * sumY + n * meanY * meanY;
+ // double centeredSumXY = sumXY - meanY * sumX - meanX * sumY + n * meanX * meanY;
+ double centeredSumXY = sumXY - meanY * sumX;
+ // double centeredSumX2 = sumX2 - 2.0 * meanX * sumX + n * meanX * meanX;
+ double centeredSumX2 = sumX2 - meanX * sumX;
+ // double centeredSumY2 = sumY2 - 2.0 * meanY * sumY + n * meanY * meanY;
+ double centeredSumY2 = sumY2 - meanY * sumY;
double result = computeResult(count, centeredSumXY, centeredSumX2, centeredSumY2, sumXYdiff2);