From 5179d78ef8f8fbf5032796c407f944b841ab3b31 Mon Sep 17 00:00:00 2001 From: "Mark R. Diggory" Date: Wed, 18 Jun 2003 03:05:45 +0000 Subject: [PATCH] Simplified calculation, removing extra division. git-svn-id: https://svn.apache.org/repos/asf/jakarta/commons/proper/math/trunk@140922 13f79535-47bb-0310-9956-ffa450edef68 --- src/java/org/apache/commons/math/stat/StatUtils.java | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/src/java/org/apache/commons/math/stat/StatUtils.java b/src/java/org/apache/commons/math/stat/StatUtils.java index ca0849c63..b601db6e9 100644 --- a/src/java/org/apache/commons/math/stat/StatUtils.java +++ b/src/java/org/apache/commons/math/stat/StatUtils.java @@ -180,7 +180,8 @@ public class StatUtils { accum += Math.pow((values[i] - mean), 2.0); accum2 += (values[i] - mean); } - variance = (accum - (Math.pow(accum2,2)/(double)values.length)) / (double)(values.length - 1); + variance = ((accum*(double)values.length) - Math.pow(accum2,2)) / + (double)(values.length*(values.length - 1)); } return variance; }