From 52806e4450d4b6ec667e564bb1326b8170ebbeb2 Mon Sep 17 00:00:00 2001
From: Artyom Baranovskiy <Artyom.Baranovskiy@gmail.com>
Date: Mon, 14 Jan 2013 15:35:50 +0300
Subject: [PATCH] Fix formula for computing kurtosis (provided by
 machinelearning.ru)

---
 src/Numerics/Statistics/DescriptiveStatistics.cs | 6 ++----
 1 file changed, 2 insertions(+), 4 deletions(-)

diff --git a/src/Numerics/Statistics/DescriptiveStatistics.cs b/src/Numerics/Statistics/DescriptiveStatistics.cs
index b89784b4..6e392615 100644
--- a/src/Numerics/Statistics/DescriptiveStatistics.cs
+++ b/src/Numerics/Statistics/DescriptiveStatistics.cs
@@ -357,10 +357,8 @@ namespace MathNet.Numerics.Statistics
 
                     if (n > 3)
                     {
-                        Kurtosis = (((double)n * (n + 1))
-                                    / ((n - 1) * (n - 2) * (n - 3))
-                                    * (kurtosis / (Variance * Variance)))
-                                   - ((3.0 * (n - 1) * (n - 1)) / ((n - 2) * (n - 3)));
+                        Kurtosis = ((double)n * n - 1) / ((n - 2) * (n - 3))
+                            * (n * kurtosis / (variance * variance) - 3 + 6.0 / (n + 1));
                     }
                 }
             }