From d15f592f3ec6b63fb6212182b2b96865da9b3120 Mon Sep 17 00:00:00 2001
From: Christoph Ruegg <git@cdrnet.ch>
Date: Sat, 19 May 2012 20:17:31 +0200
Subject: [PATCH] Normal Distribution: fix Variance property setter

The variance setter was passing the variance as standard distribution,
instead of its square root. Reported by Peter126 at Codeplex.
---
 src/Numerics/Distributions/Continuous/Normal.cs           | 2 +-
 src/UnitTests/DistributionTests/Continuous/NormalTests.cs | 8 ++++++--
 2 files changed, 7 insertions(+), 3 deletions(-)

diff --git a/src/Numerics/Distributions/Continuous/Normal.cs b/src/Numerics/Distributions/Continuous/Normal.cs
index 73e58ca2..f497e3f5 100644
--- a/src/Numerics/Distributions/Continuous/Normal.cs
+++ b/src/Numerics/Distributions/Continuous/Normal.cs
@@ -230,7 +230,7 @@ namespace MathNet.Numerics.Distributions
 
             set
             {
-                SetParameters(_mean, value);
+                SetParameters(_mean, Math.Sqrt(value));
             }
         }
 
diff --git a/src/UnitTests/DistributionTests/Continuous/NormalTests.cs b/src/UnitTests/DistributionTests/Continuous/NormalTests.cs
index 6a5bb987..d1a6a8ad 100644
--- a/src/UnitTests/DistributionTests/Continuous/NormalTests.cs
+++ b/src/UnitTests/DistributionTests/Continuous/NormalTests.cs
@@ -193,10 +193,12 @@ namespace MathNet.Numerics.UnitTests.DistributionTests.Continuous
         [TestCase(Double.PositiveInfinity)]
         public void CanSetVariance(double var)
         {
-            new Normal
+            var dist = new Normal
             {
                 Variance = var
             };
+
+            Assert.AreEqual(var, dist.Variance, 1e-14);
         }
 
         /// <summary>
@@ -221,10 +223,12 @@ namespace MathNet.Numerics.UnitTests.DistributionTests.Continuous
         [TestCase(Double.PositiveInfinity)]
         public void CanSetStdDev(double sdev)
         {
-            new Normal
+            var dist = new Normal
             {
                 StdDev = sdev
             };
+
+            Assert.AreEqual(sdev, dist.StdDev, 1e-14);
         }
 
         /// <summary>