diff --git a/src/Managed.UnitTests/DistributionTests/CommonDistributionTests.cs b/src/Managed.UnitTests/DistributionTests/CommonDistributionTests.cs
new file mode 100644
index 00000000..8adf6d33
--- /dev/null
+++ b/src/Managed.UnitTests/DistributionTests/CommonDistributionTests.cs
@@ -0,0 +1,83 @@
+//
+// Math.NET Numerics, part of the Math.NET Project
+// http://mathnet.opensourcedotnet.info
+//
+// Copyright (c) 2009 Math.NET
+//
+// Permission is hereby granted, free of charge, to any person
+// obtaining a copy of this software and associated documentation
+// files (the "Software"), to deal in the Software without
+// restriction, including without limitation the rights to use,
+// copy, modify, merge, publish, distribute, sublicense, and/or sell
+// copies of the Software, and to permit persons to whom the
+// Software is furnished to do so, subject to the following
+// conditions:
+//
+// The above copyright notice and this permission notice shall be
+// included in all copies or substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+// EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES
+// OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+// NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
+// HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
+// WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+// FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
+// OTHER DEALINGS IN THE SOFTWARE.
+//
+
+namespace MathNet.Numerics.UnitTests.DistributionTests
+{
+ using System;
+ using System.Linq;
+ using MbUnit.Framework;
+ using MathNet.Numerics.Distributions;
+
+ [TestFixture]
+ public class CommonDistributionTests
+ {
+ private IDistribution[] dists;
+
+ [SetUp]
+ public void SetupDistributions()
+ {
+ dists = new IDistribution[4];
+
+ dists[0] = new Beta(1.0, 1.0);
+ dists[1] = new ContinuousUniform(0.0, 1.0);
+ dists[2] = new Gamma(1.0, 1.0);
+ dists[3] = new Normal(0.0, 1.0);
+ }
+
+ [Test]
+ [Row(0)]
+ [Row(1)]
+ [Row(2)]
+ [Row(3)]
+ public void CanCreateNormal(int i)
+ {
+ Assert.IsNotNull(dists[i].RandomSource);
+ }
+
+ [Test]
+ [Row(0)]
+ [Row(1)]
+ [Row(2)]
+ [Row(3)]
+ public void CanSetRandomSource(int i)
+ {
+ dists[i].RandomSource = new Random();
+ }
+
+ [Test]
+ [Row(0)]
+ [Row(1)]
+ [Row(2)]
+ [Row(3)]
+ [ExpectedException(typeof(ArgumentNullException))]
+ public void FailSetRandomSourceWithNullReference(int i)
+ {
+ dists[i].RandomSource = null;
+ }
+ }
+}
diff --git a/src/Managed.UnitTests/DistributionTests/Continuous/BetaTests.cs b/src/Managed.UnitTests/DistributionTests/Continuous/BetaTests.cs
new file mode 100644
index 00000000..ebc129eb
--- /dev/null
+++ b/src/Managed.UnitTests/DistributionTests/Continuous/BetaTests.cs
@@ -0,0 +1,378 @@
+//
+// Math.NET Numerics, part of the Math.NET Project
+// http://mathnet.opensourcedotnet.info
+//
+// Copyright (c) 2009 Math.NET
+//
+// Permission is hereby granted, free of charge, to any person
+// obtaining a copy of this software and associated documentation
+// files (the "Software"), to deal in the Software without
+// restriction, including without limitation the rights to use,
+// copy, modify, merge, publish, distribute, sublicense, and/or sell
+// copies of the Software, and to permit persons to whom the
+// Software is furnished to do so, subject to the following
+// conditions:
+//
+// The above copyright notice and this permission notice shall be
+// included in all copies or substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+// EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES
+// OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+// NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
+// HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
+// WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+// FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
+// OTHER DEALINGS IN THE SOFTWARE.
+//
+
+namespace MathNet.Numerics.UnitTests.DistributionTests
+{
+ using System;
+ using System.Linq;
+ using MbUnit.Framework;
+ using MathNet.Numerics.Distributions;
+
+ [TestFixture]
+ public class BetaTests
+ {
+ [SetUp]
+ public void SetUp()
+ {
+ Control.CheckDistributionParameters = true;
+ }
+
+ [Test, MultipleAsserts]
+ [Row(0.0, 0.0)]
+ [Row(0.0, 0.1)]
+ [Row(1.0, 0.0)]
+ [Row(1.0, 1.0)]
+ [Row(9.0, 1.0)]
+ [Row(5.0, 100.0)]
+ [Row(1.0, Double.PositiveInfinity)]
+ [Row(Double.PositiveInfinity, 1.0)]
+ [Row(0.0, Double.PositiveInfinity)]
+ [Row(Double.PositiveInfinity, 0.0)]
+ public void CanCreateBeta(double a, double b)
+ {
+ var n = new Beta(a, b);
+ AssertEx.AreEqual(a, n.A);
+ AssertEx.AreEqual(b, n.B);
+ }
+
+ [Test]
+ [ExpectedException(typeof(ArgumentOutOfRangeException))]
+ [Row(Double.NaN, 1.0)]
+ [Row(1.0, Double.NaN)]
+ [Row(Double.NaN, Double.NaN)]
+ [Row(1.0, -1.0)]
+ [Row(-1.0, 1.0)]
+ [Row(-1.0, -1.0)]
+ public void BetaCreateFailsWithBadParameters(double a, double b)
+ {
+ var n = new Beta(a, b);
+ }
+
+ [Test]
+ public void ValidateToString()
+ {
+ var n = new Beta(1.0, 2.0);
+ AssertEx.AreEqual("Beta(A = 1, B = 2)", n.ToString());
+ }
+
+ [Test]
+ [Row(-0.0)]
+ [Row(0.0)]
+ [Row(0.1)]
+ [Row(1.0)]
+ [Row(10.0)]
+ [Row(Double.PositiveInfinity)]
+ public void CanSetShapeA(double a)
+ {
+ var n = new Beta(1.0, 1.0);
+ n.A = a;
+ }
+
+ [Test]
+ [ExpectedException(typeof(ArgumentOutOfRangeException))]
+ public void SetShapeAFailsWithNegativeA()
+ {
+ var n = new Beta(1.0, 1.0);
+ n.A = -1.0;
+ }
+
+ [Test]
+ [Row(-0.0)]
+ [Row(0.0)]
+ [Row(0.1)]
+ [Row(1.0)]
+ [Row(10.0)]
+ [Row(Double.PositiveInfinity)]
+ public void CanSetShapeB(double b)
+ {
+ var n = new Beta(1.0, 1.0);
+ n.B = b;
+ }
+
+ [Test]
+ [ExpectedException(typeof(ArgumentOutOfRangeException))]
+ public void SetShapeBFailsWithNegativeB()
+ {
+ var n = new Beta(1.0, 1.0);
+ n.B = -1.0;
+ }
+
+ [Test]
+ [Row(0.0, 0.0, 0.5)]
+ [Row(0.0, 0.1, 0.1)]
+ [Row(1.0, 0.0, 1.0)]
+ [Row(1.0, 1.0, 0.5)]
+ [Row(9.0, 1.0, 0.9)]
+ [Row(5.0, 100.0, 0.047619047619047619047616)]
+ [Row(1.0, Double.PositiveInfinity, 1.0)]
+ [Row(Double.PositiveInfinity, 1.0, 0.0)]
+ [Row(0.0, Double.PositiveInfinity, 1.0)]
+ [Row(Double.PositiveInfinity, 0.0, 0.0)]
+ public void ValidateMean(double a, double b, double mean)
+ {
+ var n = new Beta(a, b);
+ AssertEx.AreEqual(mean, n.Mean);
+ }
+
+ [Test]
+ [Row(0.0, 0.0, 0.5)]
+ [Row(0.0, 0.1, 0.1)]
+ [Row(1.0, 0.0, 1.0)]
+ [Row(1.0, 1.0, 0.0)]
+ [Row(9.0, 1.0, -1.3083356884473304939016015849561625204060922267565917)]
+ [Row(5.0, 100.0, -2.5201623187602743679459255108827601222133603091753153)]
+ [Row(1.0, Double.PositiveInfinity, 0.0)]
+ [Row(Double.PositiveInfinity, 1.0, 0.0)]
+ [Row(0.0, Double.PositiveInfinity, 0.0)]
+ [Row(Double.PositiveInfinity, 0.0, 0.0)]
+ public void ValidateEntropy(double a, double b, double entropy)
+ {
+ var n = new Beta(a, b);
+ AssertEx.AreEqual(entropy, n.Entropy);
+ }
+
+ [Test]
+ [Row(0.0, 0.0, 0.0)]
+ [Row(0.0, 0.1, 2.0)]
+ [Row(1.0, 0.0, -2.0)]
+ [Row(1.0, 1.0, 0.0)]
+ [Row(9.0, 1.0, -1.4740554623801777107177478829647496373009282424841579)]
+ [Row(5.0, 100.0, 0.81759410927553430354583159143895018978562196953345572)]
+ [Row(1.0, Double.PositiveInfinity, 2.0)]
+ [Row(Double.PositiveInfinity, 1.0, -2.0)]
+ [Row(0.0, Double.PositiveInfinity, 2.0)]
+ [Row(Double.PositiveInfinity, 0.0, -2.0)]
+ public void ValidateSkewness(double a, double b, double skewness)
+ {
+ var n = new Beta(a, b);
+ AssertEx.AreEqual(skewness, n.Skewness);
+ }
+
+ [Test]
+ [Row(0.0, 0.0, 0.5)]
+ [Row(0.0, 0.1, 1.0)]
+ [Row(1.0, 0.0, 0.0)]
+ [Row(1.0, 1.0, 0.5)]
+ [Row(9.0, 1.0, 1.0)]
+ [Row(5.0, 100.0, 0.038834951456310676243255386452801758423447608947753906)]
+ [Row(1.0, Double.PositiveInfinity, 0.0)]
+ [Row(Double.PositiveInfinity, 1.0, 1.0)]
+ [Row(0.0, Double.PositiveInfinity, 0.0)]
+ [Row(Double.PositiveInfinity, 0.0, 1.0)]
+ public void ValidateMode(double a, double b, double mode)
+ {
+ var n = new Beta(a, b);
+ AssertEx.AreEqual(mode, n.Mode);
+ }
+
+ [Test]
+ [ExpectedException(typeof(NotSupportedException))]
+ [Row(0.0, 0.0)]
+ [Row(0.0, 0.1)]
+ [Row(1.0, 0.0)]
+ [Row(1.0, 1.0)]
+ [Row(9.0, 1.0)]
+ [Row(5.0, 100.0)]
+ [Row(1.0, Double.PositiveInfinity)]
+ [Row(Double.PositiveInfinity, 1.0)]
+ [Row(0.0, Double.PositiveInfinity)]
+ [Row(Double.PositiveInfinity, 0.0)]
+ public void ValidateMedian(double a, double b)
+ {
+ var n = new Beta(a, 1.0);
+ var m = n.Median;
+ }
+
+ [Test]
+ public void ValidateMinimum()
+ {
+ var n = new Beta(1.0, 1.0);
+ AssertEx.AreEqual(0.0, n.Minimum);
+ }
+
+ [Test]
+ public void ValidateMaximum()
+ {
+ var n = new Beta(1.0, 1.0);
+ AssertEx.AreEqual(1.0, n.Maximum);
+ }
+
+ [Test]
+ public void CanSampleStatic()
+ {
+ var d = Beta.Sample(new Random(), 2.0, 3.0);
+ }
+
+ [Test]
+ public void CanSampleSequenceStatic()
+ {
+ var ied = Beta.Samples(new Random(), 2.0, 3.0);
+ var arr = ied.Take(5).ToArray();
+ }
+
+ [Test]
+ [ExpectedException(typeof(ArgumentOutOfRangeException))]
+ public void FailSampleStatic()
+ {
+ var d = Beta.Sample(new Random(), 1.0, -1.0);
+ }
+
+ [Test]
+ [ExpectedException(typeof(ArgumentOutOfRangeException))]
+ public void FailSampleSequenceStatic()
+ {
+ var ied = Beta.Samples(new Random(), 1.0, -1.0).First();
+ }
+
+ [Test]
+ public void CanSample()
+ {
+ var n = new Beta(2.0, 3.0);
+ var d = n.Sample();
+ }
+
+ [Test]
+ public void CanSampleSequence()
+ {
+ var n = new Beta(2.0, 3.0);
+ var ied = n.Samples();
+ var e = ied.Take(5).ToArray();
+ }
+
+ [Test]
+ [Row(0.0, 0.0, 0.0, Double.PositiveInfinity)]
+ [Row(0.0, 0.0, 0.5, 0.0)]
+ [Row(0.0, 0.0, 1.0, Double.PositiveInfinity)]
+ [Row(0.0, 0.1, 0.0, Double.PositiveInfinity)]
+ [Row(0.0, 0.1, 0.5, 0.0)]
+ [Row(0.0, 0.1, 1.0, 0.0)]
+ [Row(1.0, 0.0, 0.0, 0.0)]
+ [Row(1.0, 0.0, 0.5, 0.0)]
+ [Row(1.0, 0.0, 1.0, Double.PositiveInfinity)]
+ [Row(1.0, 1.0, 0.0, 1.0)]
+ [Row(1.0, 1.0, 0.5, 1.0)]
+ [Row(1.0, 1.0, 1.0, 1.0)]
+ [Row(9.0, 1.0, 0.0, 0.0)]
+ [Row(9.0, 1.0, 0.5, 0.035155378090821160189479427593561667617370600927556366)]
+ [Row(9.0, 1.0, 1.0, 8.9997767912502170085067334639517869100468738374544298)]
+ [Row(5.0, 100.0, 0.0, 0.0)]
+ [Row(5.0, 100.0, 0.5, 1.0881845516040810386311829462908430145307026037926335e-21)]
+ [Row(5.0, 100.0, 1.0, 0.0)]
+ [Row(1.0, Double.PositiveInfinity, 0.0, Double.PositiveInfinity)]
+ [Row(1.0, Double.PositiveInfinity, 0.5, 0.0)]
+ [Row(1.0, Double.PositiveInfinity, 1.0, 0.0)]
+ [Row(Double.PositiveInfinity, 1.0, 0.0, 0.0)]
+ [Row(Double.PositiveInfinity, 1.0, 0.5, 0.0)]
+ [Row(Double.PositiveInfinity, 1.0, 1.0, Double.PositiveInfinity)]
+ [Row(0.0, Double.PositiveInfinity, 0.0, Double.PositiveInfinity)]
+ [Row(0.0, Double.PositiveInfinity, 0.5, 0.0)]
+ [Row(0.0, Double.PositiveInfinity, 1.0, 0.0)]
+ [Row(Double.PositiveInfinity, 0.0, 0.0, 0.0)]
+ [Row(Double.PositiveInfinity, 0.0, 0.5, 0.0)]
+ [Row(Double.PositiveInfinity, 0.0, 1.0, Double.PositiveInfinity)]
+ public void ValidateDensity(double a, double b, double x, double pdf)
+ {
+ var n = new Beta(a, b);
+ AssertHelpers.AlmostEqual(pdf, n.Density(x), 15);
+ }
+
+ [Test]
+ [Row(0.0, 0.0, 0.0, Double.PositiveInfinity)]
+ [Row(0.0, 0.0, 0.5, Double.NegativeInfinity)]
+ [Row(0.0, 0.0, 1.0, Double.PositiveInfinity)]
+ [Row(0.0, 0.1, 0.0, Double.PositiveInfinity)]
+ [Row(0.0, 0.1, 0.5, Double.NegativeInfinity)]
+ [Row(0.0, 0.1, 1.0, Double.NegativeInfinity)]
+ [Row(1.0, 0.0, 0.0, Double.NegativeInfinity)]
+ [Row(1.0, 0.0, 0.5, Double.NegativeInfinity)]
+ [Row(1.0, 0.0, 1.0, Double.PositiveInfinity)]
+ [Row(1.0, 1.0, 0.0, 0.0)]
+ [Row(1.0, 1.0, 0.5, 0.0)]
+ [Row(1.0, 1.0, 1.0, 0.0)]
+ [Row(9.0, 1.0, 0.0, Double.NegativeInfinity)]
+ [Row(9.0, 1.0, 0.5, -3.3479528671433430925473664978203611353090199592365404)]
+ [Row(9.0, 1.0, 1.0, 2.197199776056471990627201569939718235188380979206923)]
+ [Row(5.0, 100.0, 0.0, Double.NegativeInfinity)]
+ [Row(5.0, 100.0, 0.5, -51.447830024537682154565870837960406410586196074573801)]
+ [Row(5.0, 100.0, 1.0, Double.NegativeInfinity)]
+ [Row(1.0, Double.PositiveInfinity, 0.0, Double.PositiveInfinity)]
+ [Row(1.0, Double.PositiveInfinity, 0.5, Double.NegativeInfinity)]
+ [Row(1.0, Double.PositiveInfinity, 1.0, Double.NegativeInfinity)]
+ [Row(Double.PositiveInfinity, 1.0, 0.0, Double.NegativeInfinity)]
+ [Row(Double.PositiveInfinity, 1.0, 0.5, Double.NegativeInfinity)]
+ [Row(Double.PositiveInfinity, 1.0, 1.0, Double.PositiveInfinity)]
+ [Row(0.0, Double.PositiveInfinity, 0.0, Double.PositiveInfinity)]
+ [Row(0.0, Double.PositiveInfinity, 0.5, Double.NegativeInfinity)]
+ [Row(0.0, Double.PositiveInfinity, 1.0, Double.NegativeInfinity)]
+ [Row(Double.PositiveInfinity, 0.0, 0.0, Double.NegativeInfinity)]
+ [Row(Double.PositiveInfinity, 0.0, 0.5, Double.NegativeInfinity)]
+ [Row(Double.PositiveInfinity, 0.0, 1.0, Double.PositiveInfinity)]
+ public void ValidateDensityLn(double a, double b, double x, double pdfln)
+ {
+ var n = new Beta(a, b);
+ AssertHelpers.AlmostEqual(pdfln, n.DensityLn(x), 15);
+ }
+
+ [Test]
+ [Row(0.0, 0.0, 0.0, 0.5)]
+ [Row(0.0, 0.0, 0.5, 0.5)]
+ [Row(0.0, 0.0, 1.0, 1.0)]
+ [Row(0.0, 0.1, 0.0, 1.0)]
+ [Row(0.0, 0.1, 0.5, 1.0)]
+ [Row(0.0, 0.1, 1.0, 1.0)]
+ [Row(1.0, 0.0, 0.0, 0.0)]
+ [Row(1.0, 0.0, 0.5, 0.0)]
+ [Row(1.0, 0.0, 1.0, 1.0)]
+ [Row(1.0, 1.0, 0.0, 0.0)]
+ [Row(1.0, 1.0, 0.5, 0.5)]
+ [Row(1.0, 1.0, 1.0, 1.0)]
+ [Row(9.0, 1.0, 0.0, 0.0)]
+ [Row(9.0, 1.0, 0.5, 0.00195313)]
+ [Row(9.0, 1.0, 1.0, 1.0)]
+ [Row(5.0, 100.0, 0.0, 0.0)]
+ [Row(5.0, 100.0, 0.5, 1.0)]
+ [Row(5.0, 100.0, 1.0, 1.0)]
+ [Row(1.0, Double.PositiveInfinity, 0.0, 1.0)]
+ [Row(1.0, Double.PositiveInfinity, 0.5, 1.0)]
+ [Row(1.0, Double.PositiveInfinity, 1.0, 1.0)]
+ [Row(Double.PositiveInfinity, 1.0, 0.0, 0.0)]
+ [Row(Double.PositiveInfinity, 1.0, 0.5, 0.0)]
+ [Row(Double.PositiveInfinity, 1.0, 1.0, 1.0)]
+ [Row(0.0, Double.PositiveInfinity, 0.0, 1.0)]
+ [Row(0.0, Double.PositiveInfinity, 0.5, 1.0)]
+ [Row(0.0, Double.PositiveInfinity, 1.0, 1.0)]
+ [Row(Double.PositiveInfinity, 0.0, 0.0, 0.0)]
+ [Row(Double.PositiveInfinity, 0.0, 0.5, 0.0)]
+ [Row(Double.PositiveInfinity, 0.0, 1.0, 1.0)]
+ public void ValidateCumulativeDistribution(double a, double b, double x, double cdf)
+ {
+ var n = new Beta(a, b);
+ AssertHelpers.AlmostEqual(cdf, n.CumulativeDistribution(x), 15);
+ }
+ }
+}
diff --git a/src/Managed.UnitTests/DistributionTests/Continuous/ContinuousUniformTests.cs b/src/Managed.UnitTests/DistributionTests/Continuous/ContinuousUniformTests.cs
index daf8fbe0..5d0be8b3 100644
--- a/src/Managed.UnitTests/DistributionTests/Continuous/ContinuousUniformTests.cs
+++ b/src/Managed.UnitTests/DistributionTests/Continuous/ContinuousUniformTests.cs
@@ -83,21 +83,6 @@ namespace MathNet.Numerics.UnitTests.DistributionTests
AssertEx.AreEqual("ContinuousUniform(Lower = 1, Upper = 2)", n.ToString());
}
- [Test]
- public void CanGetRandomSource()
- {
- var n = new ContinuousUniform();
- var rs = n.RandomSource;
- Assert.IsNotNull(rs);
- }
-
- [Test]
- public void CanSetRandomSource()
- {
- var n = new ContinuousUniform();
- n.RandomSource = new Random();
- }
-
[Test]
[Row(-10.0)]
[Row(-0.0)]
@@ -272,11 +257,7 @@ namespace MathNet.Numerics.UnitTests.DistributionTests
public void CanSampleSequenceStatic()
{
var ied = ContinuousUniform.Samples(new Random(), 0.0, 1.0);
- var e = ied.GetEnumerator();
- e.MoveNext();
- var d = e.Current;
- e.MoveNext();
- var g = e.Current;
+ var arr = ied.Take(5).ToArray();
}
[Test]
diff --git a/src/Managed.UnitTests/DistributionTests/Continuous/GammaTests.cs b/src/Managed.UnitTests/DistributionTests/Continuous/GammaTests.cs
new file mode 100644
index 00000000..ae7557d4
--- /dev/null
+++ b/src/Managed.UnitTests/DistributionTests/Continuous/GammaTests.cs
@@ -0,0 +1,393 @@
+//
+// Math.NET Numerics, part of the Math.NET Project
+// http://mathnet.opensourcedotnet.info
+//
+// Copyright (c) 2009 Math.NET
+//
+// Permission is hereby granted, free of charge, to any person
+// obtaining a copy of this software and associated documentation
+// files (the "Software"), to deal in the Software without
+// restriction, including without limitation the rights to use,
+// copy, modify, merge, publish, distribute, sublicense, and/or sell
+// copies of the Software, and to permit persons to whom the
+// Software is furnished to do so, subject to the following
+// conditions:
+//
+// The above copyright notice and this permission notice shall be
+// included in all copies or substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+// EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES
+// OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+// NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
+// HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
+// WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+// FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
+// OTHER DEALINGS IN THE SOFTWARE.
+//
+
+namespace MathNet.Numerics.UnitTests.DistributionTests
+{
+ using System;
+ using System.Linq;
+ using MbUnit.Framework;
+ using MathNet.Numerics.Distributions;
+
+ [TestFixture]
+ public class GammaTests
+ {
+ [SetUp]
+ public void SetUp()
+ {
+ Control.CheckDistributionParameters = true;
+ }
+
+ [Test, MultipleAsserts]
+ [Row(0.0, 0.0)]
+ [Row(1.0, 0.1)]
+ [Row(1.0, 1.0)]
+ [Row(10.0, 10.0)]
+ [Row(10.0, 1.0)]
+ [Row(10.0, Double.PositiveInfinity)]
+ public void CanCreateGamma(double shape, double invScale)
+ {
+ var n = new Gamma(shape, invScale);
+ AssertEx.AreEqual(shape, n.Shape);
+ AssertEx.AreEqual(invScale, n.InvScale);
+ }
+
+ [Test]
+ [ExpectedException(typeof(ArgumentOutOfRangeException))]
+ [Row(Double.NaN, 1.0)]
+ [Row(1.0, Double.NaN)]
+ [Row(Double.NaN, Double.NaN)]
+ [Row(1.0, -1.0)]
+ [Row(-1.0, 1.0)]
+ [Row(-1.0, -1.0)]
+ public void GammaCreateFailsWithBadParameters(double shape, double invScale)
+ {
+ var n = new Gamma(shape, invScale);
+ }
+
+ [Test, MultipleAsserts]
+ [Row(0.0, 0.0)]
+ [Row(1.0, 0.1)]
+ [Row(1.0, 1.0)]
+ [Row(10.0, 10.0)]
+ [Row(10.0, 1.0)]
+ [Row(10.0, Double.PositiveInfinity)]
+ public void CanCreateGammaWithShapeInvScale(double shape, double invScale)
+ {
+ var n = Gamma.WithShapeInvScale(shape, invScale);
+ AssertEx.AreEqual(shape, n.Shape);
+ AssertEx.AreEqual(invScale, n.InvScale);
+ }
+
+ [Test, MultipleAsserts]
+ [Row(0.0, 0.0)]
+ [Row(1.0, 0.1)]
+ [Row(1.0, 1.0)]
+ [Row(10.0, 10.0)]
+ [Row(10.0, 1.0)]
+ [Row(10.0, Double.PositiveInfinity)]
+ public void CanCreateGammaWithShapeScale(double shape, double scale)
+ {
+ var n = Gamma.WithShapeScale(shape, scale);
+ AssertEx.AreEqual(shape, n.Shape);
+ AssertEx.AreEqual(scale, n.Scale);
+ }
+
+ [Test]
+ public void ValidateToString()
+ {
+ var n = new Gamma(1.0, 2.0);
+ AssertEx.AreEqual("Gamma(Shape = 1, Inverse Scale = 2)", n.ToString());
+ }
+
+ [Test]
+ [Row(-0.0)]
+ [Row(0.0)]
+ [Row(0.1)]
+ [Row(1.0)]
+ [Row(10.0)]
+ [Row(Double.PositiveInfinity)]
+ public void CanSetShape(double shape)
+ {
+ var n = new Gamma(1.0, 1.0);
+ n.Shape = shape;
+ }
+
+ [Test]
+ [ExpectedException(typeof(ArgumentOutOfRangeException))]
+ public void SetShapeFailsWithNegativeShape()
+ {
+ var n = new Gamma(1.0, 1.0);
+ n.Shape = -1.0;
+ }
+
+ [Test]
+ [Row(-0.0)]
+ [Row(0.0)]
+ [Row(0.1)]
+ [Row(1.0)]
+ [Row(10.0)]
+ [Row(Double.PositiveInfinity)]
+ public void CanSetScale(double scale)
+ {
+ var n = new Gamma(1.0, 1.0);
+ n.Scale = scale;
+ }
+
+ [Test]
+ [ExpectedException(typeof(ArgumentOutOfRangeException))]
+ public void SetScaleFailsWithNegativeScale()
+ {
+ var n = new Gamma(1.0, 1.0);
+ n.Scale = -1.0;
+ }
+
+ [Test]
+ [Row(-0.0)]
+ [Row(0.0)]
+ [Row(0.1)]
+ [Row(1.0)]
+ [Row(10.0)]
+ [Row(Double.PositiveInfinity)]
+ public void CanSetInvScale(double invScale)
+ {
+ var n = new Gamma(1.0, 1.0);
+ n.InvScale = invScale;
+ }
+
+ [Test]
+ [ExpectedException(typeof(ArgumentOutOfRangeException))]
+ public void SetInvScaleFailsWithNegativeInvScale()
+ {
+ var n = new Gamma(1.0, 1.0);
+ n.InvScale = -1.0;
+ }
+
+ [Test]
+ [Row(0.0, 0.0, 0.0)]
+ [Row(1.0, 0.1, 10.0)]
+ [Row(1.0, 1.0, 1.0)]
+ [Row(10.0, 10.0, 1.0)]
+ [Row(10.0, 1.0, 10.0)]
+ [Row(10.0, Double.PositiveInfinity, 0.0)]
+ public void CanGetMean(double shape, double invScale, double mean)
+ {
+ var n = new Gamma(shape, invScale);
+ AssertEx.AreEqual(mean, n.Mean);
+ }
+
+ [Test]
+ [Row(0.0, 0.0, 0.0)]
+ [Row(1.0, 0.1, 100.0)]
+ [Row(1.0, 1.0, 1.0)]
+ [Row(10.0, 10.0, 0.1)]
+ [Row(10.0, 1.0, 10.0)]
+ [Row(10.0, Double.PositiveInfinity, 0.0)]
+ public void CanGetVariance(double shape, double invScale, double var)
+ {
+ var n = new Gamma(shape, invScale);
+ AssertEx.AreEqual(var, n.Variance);
+ }
+
+ [Test]
+ [Row(0.0, 0.0, 0.0)]
+ [Row(1.0, 0.1, 10.0)]
+ [Row(1.0, 1.0, 1.0)]
+ [Row(10.0, 10.0, 0.31622776601683794197697302588502426416723164097476643)]
+ [Row(10.0, 1.0, 3.1622776601683793319988935444327185337195551393252168)]
+ [Row(10.0, Double.PositiveInfinity, 0.0)]
+ public void CanGetStdDev(double shape, double invScale, double sdev)
+ {
+ var n = new Gamma(shape, invScale);
+ AssertHelpers.AlmostEqual(sdev, n.StdDev, 15);
+ }
+
+ [Test]
+ [Row(0.0, 0.0, Double.PositiveInfinity)]
+ [Row(1.0, 0.1, 3.3025850929940456285068402234265387271634735938763824)]
+ [Row(1.0, 1.0, 1.0)]
+ [Row(10.0, 10.0, 0.23346908548693395836262094490967812177376750477943892)]
+ [Row(10.0, 1.0, 2.5360541784809796423806123995940423293748689934081866)]
+ [Row(10.0, Double.PositiveInfinity, 0.0)]
+ public void ValidateEntropy(double shape, double invScale, double entropy)
+ {
+ var n = new Gamma(shape, invScale);
+ AssertHelpers.AlmostEqual(entropy, n.Entropy, 15);
+ }
+
+ [Test]
+ [Row(0.0, 0.0, Double.PositiveInfinity)]
+ [Row(1.0, 0.1, 2.0)]
+ [Row(1.0, 1.0, 2.0)]
+ [Row(10.0, 10.0, 0.63245553203367586639977870888654370674391102786504337)]
+ [Row(10.0, 1.0, 0.63245553203367586639977870888654370674391102786504337)]
+ [Row(10.0, Double.PositiveInfinity, 0.0)]
+ public void ValidateSkewness(double shape, double invScale, double skewness)
+ {
+ var n = new Gamma(shape, invScale);
+ AssertHelpers.AlmostEqual(skewness, n.Skewness, 15);
+ }
+
+ [Test]
+ [Row(0.0, 0.0, Double.PositiveInfinity)]
+ [Row(1.0, 0.1, 0.0)]
+ [Row(1.0, 1.0, 0.0)]
+ [Row(10.0, 10.0, 0.9)]
+ [Row(10.0, 1.0, 9.0)]
+ [Row(10.0, Double.PositiveInfinity, 10.0)]
+ public void ValidateMode(double shape, double invScale, double mode)
+ {
+ var n = new Gamma(shape, invScale);
+ AssertEx.AreEqual(mode, n.Mode);
+ }
+
+ [Test]
+ [ExpectedException(typeof(NotSupportedException))]
+ [Row(0.0, 0.0)]
+ [Row(1.0, 0.1)]
+ [Row(1.0, 1.0)]
+ [Row(10.0, 10.0)]
+ [Row(10.0, 1.0)]
+ [Row(10.0, Double.PositiveInfinity)]
+ public void ValidateMedian(double shape, double invScale, double mode)
+ {
+ var n = new Gamma(shape, invScale);
+ var median = n.Median;
+ }
+
+ [Test]
+ public void ValidateMinimum()
+ {
+ var n = new Gamma(1.0,1.0);
+ AssertEx.AreEqual(0.0, n.Minimum);
+ }
+
+ [Test]
+ public void ValidateMaximum()
+ {
+ var n = new Gamma(1.0, 1.0);
+ AssertEx.AreEqual(System.Double.PositiveInfinity, n.Maximum);
+ }
+
+ [Test]
+ [Row(0.0, 0.0, 0.0, 0.0)]
+ [Row(0.0, 0.0, 1.0, 0.0)]
+ [Row(0.0, 0.0, 10.0, 0.0)]
+ [Row(1.0, 0.1, 0.0, 0.10000000000000000555111512312578270211815834045410156)]
+ [Row(1.0, 0.1, 1.0, 0.099004983374916810660915381324116279472953858297127391)]
+ [Row(1.0, 0.1, 10.0, 0.036787944117144234201693506390001264039984687455876246)]
+ [Row(1.0, 1.0, 0.0, 1.0)]
+ [Row(1.0, 1.0, 1.0, 0.36787944117144232159552377016146086744581113103176804)]
+ [Row(1.0, 1.0, 10.0, 0.000045399929762484851535591515560550610237918088866564953)]
+ [Row(10.0, 10.0, 0.0, 0.0)]
+ [Row(10.0, 10.0, 1.0, 1.2511003572113329898476497894772544708420990097708588)]
+ [Row(10.0, 10.0, 10.0, 1.0251532120868705806216092933926141802686541811003037e-30)]
+ [Row(10.0, 1.0, 0.0, 0.0)]
+ [Row(10.0, 1.0, 1.0, 0.0000010137771196302974029859010421116095333052555418644397)]
+ [Row(10.0, 1.0, 10.0, 0.12511003572113329898476497894772544708420990097708601)]
+ [Row(10.0, Double.PositiveInfinity, 0.0, 0.0)]
+ [Row(10.0, Double.PositiveInfinity, 1.0, 0.0)]
+ [Row(10.0, Double.PositiveInfinity, 10.0, Double.PositiveInfinity)]
+ public void ValidateDensity(double shape, double invScale, double x, double pdf)
+ {
+ var n = new Gamma(shape, invScale);
+ AssertHelpers.AlmostEqual(pdf, n.Density(x), 15);
+ }
+
+ [Test]
+ [Row(0.0, 0.0, 0.0, Double.NegativeInfinity)]
+ [Row(0.0, 0.0, 1.0, Double.NegativeInfinity)]
+ [Row(0.0, 0.0, 10.0, Double.NegativeInfinity)]
+ [Row(1.0, 0.1, 0.0, -2.3025850929940456285068402234265387271634735938763824)]
+ [Row(1.0, 0.1, 1.0, -2.312585092994045630449730516520562672904829013035318)]
+ [Row(1.0, 0.1, 10.0, -3.3025850929940456285068402234265387271634735938763824)]
+ [Row(1.0, 1.0, 0.0, 0.0)]
+ [Row(1.0, 1.0, 1.0, -1.0)]
+ [Row(1.0, 1.0, 10.0, -10.0)]
+ [Row(10.0, 10.0, 0.0, Double.NegativeInfinity)]
+ [Row(10.0, 10.0, 1.0, 0.22402344985898722897219667227693591172986563062456522)]
+ [Row(10.0, 10.0, 10.0, -69.052710713194601614865880235563786219860220971716511)]
+ [Row(10.0, 1.0, 0.0, Double.NegativeInfinity)]
+ [Row(10.0, 1.0, 1.0, -13.801827480081469611207717874566706164281149255663166)]
+ [Row(10.0, 1.0, 10.0, -2.0785616431350584550457947824074282958712358580042068)]
+ [Row(10.0, Double.PositiveInfinity, 0.0, Double.NegativeInfinity)]
+ [Row(10.0, Double.PositiveInfinity, 1.0, Double.NegativeInfinity)]
+ [Row(10.0, Double.PositiveInfinity, 10.0, Double.PositiveInfinity)]
+ public void ValidateDensityLn(double shape, double invScale, double x, double pdfln)
+ {
+ var n = new Gamma(shape, invScale);
+ AssertHelpers.AlmostEqual(pdfln, n.DensityLn(x), 15);
+ }
+
+ [Test]
+ public void CanSampleStatic()
+ {
+ var d = Gamma.Sample(new Random(), 1.0, 1.0);
+ }
+
+ [Test]
+ public void CanSampleSequenceStatic()
+ {
+ var ied = Gamma.Samples(new Random(), 1.0, 1.0);
+ var arr = ied.Take(5).ToArray();
+ }
+
+ [Test]
+ [ExpectedException(typeof(ArgumentOutOfRangeException))]
+ public void FailSampleStatic()
+ {
+ var d = Normal.Sample(new Random(), 1.0, -1.0);
+ }
+
+ [Test]
+ [ExpectedException(typeof(ArgumentOutOfRangeException))]
+ public void FailSampleSequenceStatic()
+ {
+ var ied = Normal.Samples(new Random(), 1.0, -1.0).First();
+ }
+
+ [Test]
+ public void CanSample()
+ {
+ var n = new Normal();
+ var d = n.Sample();
+ }
+
+ [Test]
+ public void CanSampleSequence()
+ {
+ var n = new Normal();
+ var ied = n.Samples();
+ var e = ied.Take(5).ToArray();
+ }
+
+ [Test]
+ [Row(0.0, 0.0, 0.0, 0.0)]
+ [Row(0.0, 0.0, 1.0, 0.0)]
+ [Row(0.0, 0.0, 10.0, 0.0)]
+ [Row(1.0, 0.1, 0.0, 0.0)]
+ [Row(1.0, 0.1, 1.0, 0.095162581964040431858607615783064404690935346242622848)]
+ [Row(1.0, 0.1, 10.0, 0.63212055882855767840447622983853913255418886896823196)]
+ [Row(1.0, 1.0, 0.0, 0.0)]
+ [Row(1.0, 1.0, 1.0, 0.63212055882855767840447622983853913255418886896823196)]
+ [Row(1.0, 1.0, 10.0, 0.99995460007023751514846440848443944938976208191113396)]
+ [Row(10.0, 10.0, 0.0, 0.0)]
+ [Row(10.0, 10.0, 1.0, 0.54207028552814779168583514294066541824736464003242184)]
+ [Row(10.0, 10.0, 10.0, 0.99999999999999999999999999999988746526039157266114706)]
+ [Row(10.0, 1.0, 0.0, 0.0)]
+ [Row(10.0, 1.0, 1.0, 0.00000011142547833872067735305068724025236288094949815466035)]
+ [Row(10.0, 1.0, 10.0, 0.54207028552814779168583514294066541824736464003242184)]
+ [Row(10.0, Double.PositiveInfinity, 0.0, 0.0)]
+ [Row(10.0, Double.PositiveInfinity, 1.0, 0.0)]
+ [Row(10.0, Double.PositiveInfinity, 10.0, 1.0)]
+ public void ValidateCumulativeDistribution(double shape, double invScale, double x, double cdf)
+ {
+ var n = new Gamma(shape, invScale);
+ AssertHelpers.AlmostEqual(cdf, n.CumulativeDistribution(x), 15);
+ }
+ }
+}
diff --git a/src/Managed.UnitTests/DistributionTests/Continuous/NormalTests.cs b/src/Managed.UnitTests/DistributionTests/Continuous/NormalTests.cs
index 5ba4b03e..82426a7c 100644
--- a/src/Managed.UnitTests/DistributionTests/Continuous/NormalTests.cs
+++ b/src/Managed.UnitTests/DistributionTests/Continuous/NormalTests.cs
@@ -128,21 +128,6 @@ namespace MathNet.Numerics.UnitTests.DistributionTests
AssertEx.AreEqual("Normal(Mean = 1, StdDev = 2)", n.ToString());
}
- [Test]
- public void CanGetRandomSource()
- {
- var n = new Normal();
- var rs = n.RandomSource;
- Assert.IsNotNull(rs);
- }
-
- [Test]
- public void CanSetRandomSource()
- {
- var n = new Normal();
- n.RandomSource = new Random();
- }
-
[Test]
[Row(-0.0)]
[Row(0.0)]
@@ -338,11 +323,7 @@ namespace MathNet.Numerics.UnitTests.DistributionTests
public void CanSampleSequenceStatic()
{
var ied = Normal.Samples(new Random(), 0.0, 1.0);
- var e = ied.GetEnumerator();
- e.MoveNext();
- var d = e.Current;
- e.MoveNext();
- var g = e.Current;
+ var arr = ied.Take(5).ToArray();
}
[Test]
diff --git a/src/Managed.UnitTests/Managed.UnitTests.csproj b/src/Managed.UnitTests/Managed.UnitTests.csproj
index d987d51d..f140563f 100644
--- a/src/Managed.UnitTests/Managed.UnitTests.csproj
+++ b/src/Managed.UnitTests/Managed.UnitTests.csproj
@@ -62,7 +62,10 @@
+
+
+
diff --git a/src/Managed/Distributions/Continuous/Beta.cs b/src/Managed/Distributions/Continuous/Beta.cs
new file mode 100644
index 00000000..c205bd8f
--- /dev/null
+++ b/src/Managed/Distributions/Continuous/Beta.cs
@@ -0,0 +1,324 @@
+//
+// Math.NET Numerics, part of the Math.NET Project
+// http://mathnet.opensourcedotnet.info
+//
+// Copyright (c) 2009 Math.NET
+//
+// Permission is hereby granted, free of charge, to any person
+// obtaining a copy of this software and associated documentation
+// files (the "Software"), to deal in the Software without
+// restriction, including without limitation the rights to use,
+// copy, modify, merge, publish, distribute, sublicense, and/or sell
+// copies of the Software, and to permit persons to whom the
+// Software is furnished to do so, subject to the following
+// conditions:
+//
+// The above copyright notice and this permission notice shall be
+// included in all copies or substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+// EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES
+// OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+// NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
+// HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
+// WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+// FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
+// OTHER DEALINGS IN THE SOFTWARE.
+//
+
+namespace MathNet.Numerics.Distributions
+{
+ using System;
+ using System.Collections.Generic;
+ using Properties;
+
+ ///
+ /// Implements the Beta distribution. For details about this distribution, see
+ /// Wikipedia - Beta distribution.
+ ///
+ /// The distribution will use the by default.
+ /// Users can get/set the random number generator by using the property.
+ /// The statistics classes will check all the incoming parameters whether they are in the allowed
+ /// range. This might involve heavy computation. Optionally, by setting Control.CheckDistributionParameters
+ /// to false, all parameter checks can be turned off.
+ public class Beta : IContinuousDistribution
+ {
+ ///
+ /// Beta shape parameter a.
+ ///
+ private double _shapeA;
+
+ ///
+ /// Beta shape parameter b.
+ ///
+ private double _shapeB;
+
+ ///
+ /// Initializes a new instance of the Beta distribution.
+ ///
+ /// The a shape parameter of the Beta distribution.
+ /// The b shape parameter of the Beta distribution.
+ /// If any of the Beta parameters are negative.
+ public Beta(double a, double b)
+ {
+ SetParameters(a, b);
+ RandomSource = new Random();
+ }
+
+ ///
+ /// A string representation of the distribution.
+ ///
+ public override string ToString()
+ {
+ return "Beta(A = " + _shapeA + ", B = " + _shapeB + ")";
+ }
+
+ ///
+ /// Checks whether the parameters of the distribution are valid.
+ ///
+ /// The a shape parameter of the Beta distribution.
+ /// The b shape parameter of the Beta distribution.
+ /// True when the parameters are valid, false otherwise.
+ private static bool IsValidParameterSet(double a, double b)
+ {
+ if (a < 0.0 || b < 0.0)
+ {
+ return false;
+ }
+
+ return true;
+ }
+
+ ///
+ /// Sets the parameters of the distribution after checking their validity.
+ ///
+ /// The a shape parameter of the Beta distribution.
+ /// The b shape parameter of the Beta distribution.
+ /// When the parameters don't pass the function.
+ private void SetParameters(double a, double b)
+ {
+ if (Control.CheckDistributionParameters && !IsValidParameterSet(a, b))
+ {
+ throw new ArgumentOutOfRangeException(Resources.InvalidDistributionParameters);
+ }
+
+ _shapeA = a;
+ _shapeB = b;
+ }
+
+ ///
+ /// Gets or sets the A shape parameter of the Beta distribution.
+ ///
+ public double A
+ {
+ get { return _shapeA; }
+ set { SetParameters(value, _shapeB); }
+ }
+
+ ///
+ /// Gets or sets the B shape parameter of the Beta distribution.
+ ///
+ public double B
+ {
+ get { return _shapeB; }
+ set { SetParameters(_shapeA, value); }
+ }
+
+ #region IDistribution implementation
+
+ ///
+ /// Gets or sets the random number generator which is used to draw random samples.
+ ///
+ public Random RandomSource { get; set; }
+
+ ///
+ /// Gets the mean of the Beta distribution.
+ ///
+ public double Mean
+ {
+ get { return _shapeA / (_shapeA + _shapeB); }
+ }
+
+ ///
+ /// Gets the variance of the Beta distribution.
+ ///
+ public double Variance
+ {
+ get { return (_shapeA * _shapeB) / ((_shapeA + _shapeB) * (_shapeA + _shapeB) * (_shapeA + _shapeB + 1.0)); }
+ }
+
+ ///
+ /// Gets the standard deviation of the Beta distribution.
+ ///
+ public double StdDev
+ {
+ get { return Math.Sqrt((_shapeA * _shapeB) / ((_shapeA + _shapeB) * (_shapeA + _shapeB) * (_shapeA + _shapeB + 1.0))); }
+ }
+
+ ///
+ /// Gets the entropy of the Beta distribution.
+ ///
+ public double Entropy
+ {
+ get
+ {
+ return SpecialFunctions.BetaLn(_shapeA, _shapeB)
+ - (_shapeA - 1.0) * SpecialFunctions.DiGamma(_shapeA)
+ - (_shapeB - 1.0) * SpecialFunctions.DiGamma(_shapeB)
+ + (_shapeA + _shapeB - 2.0) * SpecialFunctions.DiGamma(_shapeA + _shapeB);
+ }
+ }
+
+ ///
+ /// Gets the skewness of the Beta distribution.
+ ///
+ public double Skewness
+ {
+ get
+ {
+ return 2.0 * (_shapeB - _shapeA) * Math.Sqrt(_shapeA + _shapeB + 1.0)
+ / ((_shapeA + _shapeB + 2.0) * Math.Sqrt(_shapeA * _shapeB));
+ }
+ }
+ #endregion
+
+ #region IContinuousDistribution implementation
+
+ ///
+ /// Gets the mode of the Beta distribution.
+ ///
+ public double Mode
+ {
+ get { return (_shapeA - 1) / (_shapeA + _shapeB - 2); }
+ }
+
+ ///
+ /// Gets the median of the Beta distribution.
+ ///
+ public double Median
+ {
+ get { throw new NotSupportedException(); }
+ }
+
+ ///
+ /// Gets the minimum of the Beta distribution.
+ ///
+ public double Minimum
+ {
+ get { return 0.0; }
+ }
+
+ ///
+ /// Gets the maximum of the Beta distribution.
+ ///
+ public double Maximum
+ {
+ get { return 1.0; }
+ }
+
+ ///
+ /// Computes the density of the Beta distribution.
+ ///
+ /// The location at which to compute the density.
+ /// the density at .
+ public double Density(double x)
+ {
+ double b = SpecialFunctions.Gamma(_shapeA + _shapeB) / (SpecialFunctions.Gamma(_shapeA) * SpecialFunctions.Gamma(_shapeB));
+ return b * Math.Pow(x, _shapeA - 1.0) * Math.Pow(1.0 - x, _shapeB - 1.0);
+ }
+
+ ///
+ /// Computes the log density of the Beta distribution.
+ ///
+ /// The location at which to compute the log density.
+ /// the log density at .
+ public double DensityLn(double x)
+ {
+ double b = SpecialFunctions.GammaLn(_shapeA + _shapeB) - SpecialFunctions.GammaLn(_shapeA) - SpecialFunctions.GammaLn(_shapeB);
+ return b + (_shapeA - 1.0)*Math.Log(x) + (_shapeB - 1.0)*Math.Log(1.0 - x);
+ }
+
+ ///
+ /// Computes the cumulative distribution function of the Beta distribution.
+ ///
+ /// The location at which to compute the cumulative density.
+ /// the cumulative density at .
+ public double CumulativeDistribution(double x)
+ {
+ return SpecialFunctions.BetaRegularized(_shapeA, _shapeB, x);
+ }
+
+ ///
+ /// Generates a sample from the Beta distribution.
+ ///
+ /// a sample from the distribution.
+ public double Sample()
+ {
+ return SampleBeta(RandomSource, _shapeA, _shapeB);
+ }
+
+ ///
+ /// Generates a sequence of samples from the Beta distribution.
+ ///
+ /// a sequence of samples from the distribution.
+ public IEnumerable Samples()
+ {
+ while (true)
+ {
+ yield return SampleBeta(RandomSource, _shapeA, _shapeB);
+ }
+ }
+ #endregion
+
+ ///
+ /// Generates a sample from the normal distribution using the Box-Muller algorithm.
+ ///
+ /// The random number generator to use.
+ /// The a shape parameter of the Beta distribution.
+ /// The b shape parameter of the Beta distribution.
+ /// a sample from the distribution.
+ public static double Sample(Random rng, double a, double b)
+ {
+ if (Control.CheckDistributionParameters && !IsValidParameterSet(a, b))
+ {
+ throw new ArgumentOutOfRangeException(Resources.InvalidDistributionParameters);
+ }
+
+ return SampleBeta(rng, a, b);
+ }
+
+ ///
+ /// Generates a sequence of samples from the normal distribution using the Box-Muller algorithm.
+ ///
+ /// The random number generator to use.
+ /// The a shape parameter of the Beta distribution.
+ /// The b shape parameter of the Beta distribution.
+ /// a sequence of samples from the distribution.
+ public static IEnumerable Samples(Random rng, double a, double b)
+ {
+ if (Control.CheckDistributionParameters && !IsValidParameterSet(a, b))
+ {
+ throw new ArgumentOutOfRangeException(Resources.InvalidDistributionParameters);
+ }
+
+ while (true)
+ {
+ yield return SampleBeta(rng, a, b);
+ }
+ }
+
+ ///
+ /// Samples Beta distributed random variables by sampling two Gamma variables and normalizing.
+ ///
+ /// The random number generator to use.
+ /// The A shape parameter.
+ /// The B shape parameter.
+ /// a random number from the Beta distribution.
+ internal static double SampleBeta(Random rnd, double a, double b)
+ {
+ double x = Gamma.SampleGamma(rnd, a, 1.0);
+ double y = Gamma.SampleGamma(rnd, b, 1.0);
+ return x / (x + y);
+ }
+ }
+}
diff --git a/src/Managed/Distributions/Continuous/Gamma.cs b/src/Managed/Distributions/Continuous/Gamma.cs
new file mode 100644
index 00000000..379cb71b
--- /dev/null
+++ b/src/Managed/Distributions/Continuous/Gamma.cs
@@ -0,0 +1,504 @@
+//
+// Math.NET Numerics, part of the Math.NET Project
+// http://mathnet.opensourcedotnet.info
+//
+// Copyright (c) 2009 Math.NET
+//
+// Permission is hereby granted, free of charge, to any person
+// obtaining a copy of this software and associated documentation
+// files (the "Software"), to deal in the Software without
+// restriction, including without limitation the rights to use,
+// copy, modify, merge, publish, distribute, sublicense, and/or sell
+// copies of the Software, and to permit persons to whom the
+// Software is furnished to do so, subject to the following
+// conditions:
+//
+// The above copyright notice and this permission notice shall be
+// included in all copies or substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+// EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES
+// OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+// NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
+// HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
+// WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+// FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
+// OTHER DEALINGS IN THE SOFTWARE.
+//
+
+namespace MathNet.Numerics.Distributions
+{
+ using System;
+ using System.Collections.Generic;
+ using Properties;
+
+ ///
+ /// Implements the univariate Gamma distribution. For details about this distribution, see
+ /// Wikipedia - Gamma distribution.
+ ///
+ ///
+ /// The Gamma distribution is parametrized by a shape and inverse scale parameter. When we want
+ /// to specify a Gamma distribution which is a point distribution we set the shape parameter to be the
+ /// location of the point distribution and the inverse scale as positive infinity.
+ /// Random number generation for the Gamma distribution is based on the algorithm in:
+ /// "A Simple Method for Generating Gamma Variables" - Marsaglia & Tsang
+ /// ACM Transactions on Mathematical Software, Vol. 26, No. 3, September 2000, Pages 363–372.
+ /// The distribution will use the by default.
+ /// Users can get/set the random number generator by using the property.
+ /// The statistics classes will check all the incoming parameters whether they are in the allowed
+ /// range. This might involve heavy computation. Optionally, by setting Control.CheckDistributionParameters
+ /// to false, all parameter checks can be turned off.
+ public class Gamma : IContinuousDistribution
+ {
+ ///
+ /// Gamma shape parameter.
+ ///
+ private double _shape;
+
+ ///
+ /// Gamma inverse scale parameter.
+ ///
+ private double _invScale;
+
+ ///
+ /// Initializes a new instance of the Gamma distribution.
+ ///
+ /// The shape of the Gamma distribution.
+ /// The inverse scale of the Gamma distribution.
+ public Gamma(double shape, double invScale)
+ {
+ SetParameters(shape, invScale);
+ RandomSource = new Random();
+ }
+
+ ///
+ /// Constructs a Gamma distribution from a shape and scale parameter. The distribution will
+ /// be initialized with the default random number generator.
+ ///
+ /// The shape of the Gamma distribution.
+ /// The scale of the Gamma distribution.
+ /// a normal distribution.
+ public static Gamma WithShapeScale(double shape, double scale)
+ {
+ return new Gamma(shape, 1.0/scale);
+ }
+
+ ///
+ /// Constructs a Gamma distribution from a shape and inverse scale parameter. The distribution will
+ /// be initialized with the default random number generator.
+ ///
+ /// The shape of the Gamma distribution.
+ /// The inverse scale of the Gamma distribution.
+ /// a normal distribution.
+ public static Gamma WithShapeInvScale(double shape, double invScale)
+ {
+ return new Gamma(shape, invScale);
+ }
+
+ ///
+ /// A string representation of the distribution.
+ ///
+ /// a string representation of the distribution.
+ public override string ToString()
+ {
+ return "Gamma(Shape = " + _shape + ", Inverse Scale = " + _invScale + ")";
+ }
+
+ ///
+ /// Checks whether the parameters of the distribution are valid.
+ ///
+ /// The shape of the Gamma distribution.
+ /// The inverse scale of the Gamma distribution.
+ /// True when the parameters are valid, false otherwise.
+ private static bool IsValidParameterSet(double shape, double invScale)
+ {
+ if (shape < 0.0 || invScale < 0.0 || Double.IsNaN(shape) || Double.IsNaN(invScale))
+ {
+ return false;
+ }
+
+ return true;
+ }
+
+ ///
+ /// Sets the parameters of the distribution after checking their validity.
+ ///
+ /// The shape of the Gamma distribution.
+ /// The inverse scale of the Gamma distribution.
+ /// When the parameters don't pass the function.
+ private void SetParameters(double shape, double invScale)
+ {
+ if (Control.CheckDistributionParameters && !IsValidParameterSet(shape, invScale))
+ {
+ throw new ArgumentOutOfRangeException(Resources.InvalidDistributionParameters);
+ }
+
+ _shape = shape;
+ _invScale = invScale;
+ }
+
+ ///
+ /// Gets or sets the shape of the Gamma distribution.
+ ///
+ public double Shape
+ {
+ get
+ {
+ return _shape;
+ }
+
+ set
+ {
+ SetParameters(value, _invScale);
+ }
+ }
+
+ ///
+ /// Gets or sets the scale of the Gamma distribution.
+ ///
+ public double Scale
+ {
+ get
+ {
+ return 1.0 / _invScale;
+ }
+
+ set
+ {
+ SetParameters(_shape, 1.0/value);
+ }
+ }
+
+ ///
+ /// Gets or sets the inverse scale of the Gamma distribution.
+ ///
+ public double InvScale
+ {
+ get
+ {
+ return _invScale;
+ }
+
+ set
+ {
+ SetParameters(_shape, value);
+ }
+ }
+
+ #region IDistribution implementation
+
+ ///
+ /// Gets or sets the random number generator which is used to draw random samples.
+ ///
+ public Random RandomSource { get; set; }
+
+ ///
+ /// Gets the mean of the Gamma distribution.
+ ///
+ public double Mean
+ {
+ get
+ {
+ if (Double.IsPositiveInfinity(_invScale))
+ {
+ return _shape;
+ }
+ else
+ {
+ return _shape / _invScale;
+ }
+ }
+ }
+
+ ///
+ /// Gets the variance of the Gamma distribution.
+ ///
+ public double Variance
+ {
+ get
+ {
+ if (Double.IsPositiveInfinity(_invScale))
+ {
+ return 0.0;
+ }
+ else
+ {
+ return _shape / (_invScale * _invScale);
+ }
+ }
+ }
+
+ ///
+ /// Gets the standard deviation of the Gamma distribution.
+ ///
+ public double StdDev
+ {
+ get
+ {
+ if (Double.IsPositiveInfinity(_invScale))
+ {
+ return 0.0;
+ }
+ else
+ {
+ return Math.Sqrt(_shape / (_invScale * _invScale));
+ }
+ }
+ }
+
+ ///
+ /// Gets the entropy of the Gamma distribution.
+ ///
+ public double Entropy
+ {
+ get
+ {
+ if (Double.IsPositiveInfinity(_invScale))
+ {
+ return 0.0;
+ }
+ else
+ {
+ return _shape - Math.Log(_invScale) + SpecialFunctions.GammaLn(_shape) + (1.0 - _shape) * SpecialFunctions.DiGamma(_shape);
+ }
+ }
+ }
+
+ ///
+ /// Gets the skewness of the Gamma distribution.
+ ///
+ public double Skewness
+ {
+ get { return 2.0 / Math.Sqrt(_shape); }
+ }
+ #endregion
+
+ #region IContinuousDistribution implementation
+
+ ///
+ /// Gets the mode of the Gamma distribution.
+ ///
+ public double Mode
+ {
+ get
+ {
+ if (Double.IsPositiveInfinity(_invScale))
+ {
+ return _shape;
+ }
+ else
+ {
+ return (_shape - 1.0) / _invScale;
+ }
+ }
+ }
+
+ ///
+ /// Gets the median of the Gamma distribution.
+ ///
+ public double Median
+ {
+ get { throw new NotSupportedException(); }
+ }
+
+ ///
+ /// Gets the minimum of the Gamma distribution.
+ ///
+ public double Minimum
+ {
+ get { return 0.0; }
+ }
+
+ ///
+ /// Gets the maximum of the Gamma distribution.
+ ///
+ public double Maximum
+ {
+ get { return Double.PositiveInfinity; }
+ }
+
+ ///
+ /// Computes the density of the Gamma distribution.
+ ///
+ /// The location at which to compute the density.
+ /// the density at .
+ public double Density(double x)
+ {
+ if (Double.IsPositiveInfinity(_invScale))
+ {
+ if (x == _shape)
+ {
+ return Double.PositiveInfinity;
+ }
+ else
+ {
+ return 0.0;
+ }
+ }
+ else
+ {
+ return Math.Pow(_invScale, _shape) * Math.Pow(x, _shape - 1.0) * Math.Exp(-_invScale * x) / SpecialFunctions.Gamma(_shape);
+ }
+ }
+
+ ///
+ /// Computes the log density of the Gamma distribution.
+ ///
+ /// The location at which to compute the log density.
+ /// the log density at .
+ public double DensityLn(double x)
+ {
+ if (Double.IsPositiveInfinity(_invScale))
+ {
+ if (x == _shape)
+ {
+ return Double.PositiveInfinity;
+ }
+ else
+ {
+ return Double.NegativeInfinity;
+ }
+ }
+ else
+ {
+ return _shape * Math.Log(_invScale) + (_shape - 1.0) * Math.Log(x) - _invScale * x - SpecialFunctions.GammaLn(_shape);
+ }
+ }
+
+ ///
+ /// Computes the cumulative distribution function of the Gamma distribution.
+ ///
+ /// The location at which to compute the cumulative density.
+ /// the cumulative density at .
+ public double CumulativeDistribution(double x)
+ {
+ if (Double.IsPositiveInfinity(_invScale))
+ {
+ if (x >= _shape)
+ {
+ return 1.0;
+ }
+ else
+ {
+ return 0.0;
+ }
+ }
+ else
+ {
+ return SpecialFunctions.IncompleteGamma(_shape, x * _invScale, true);
+ }
+ }
+
+ ///
+ /// Generates a sample from the Gamma distribution.
+ ///
+ /// a sample from the distribution.
+ public double Sample()
+ {
+ return SampleGamma(RandomSource, _shape, _invScale);
+ }
+
+ ///
+ /// Generates a sequence of samples from the Gamma distribution.
+ ///
+ /// a sequence of samples from the distribution.
+ public IEnumerable Samples()
+ {
+ while (true)
+ {
+ yield return SampleGamma(RandomSource, _shape, _invScale);
+ }
+ }
+ #endregion
+
+ ///
+ /// Generates a sample from the Gamma distribution.
+ ///
+ /// The random number generator to use.
+ /// The shape of the Gamma distribution from which to generate samples.
+ /// The inverse scale of the Gamma distribution from which to generate samples.
+ /// a sample from the distribution.
+ public static double Sample(Random rng, double shape, double invScale)
+ {
+ if (Control.CheckDistributionParameters && !IsValidParameterSet(shape, invScale))
+ {
+ throw new ArgumentOutOfRangeException(Resources.InvalidDistributionParameters);
+ }
+
+ return SampleGamma(rng, shape, invScale);
+ }
+
+ ///
+ /// Generates a sequence of samples from the Gamma distribution.
+ ///
+ /// The random number generator to use.
+ /// The shape of the Gamma distribution from which to generate samples.
+ /// The inverse scale of the Gamma distribution from which to generate samples.
+ /// a sequence of samples from the distribution.
+ public static IEnumerable Samples(Random rng, double shape, double invScale)
+ {
+ if (Control.CheckDistributionParameters && !IsValidParameterSet(shape, invScale))
+ {
+ throw new ArgumentOutOfRangeException(Resources.InvalidDistributionParameters);
+ }
+
+ while (true)
+ {
+ yield return SampleGamma(rng, shape, invScale);
+ }
+ }
+
+ ///
+ /// Sampling implementation based on:
+ /// "A Simple Method for Generating Gamma Variables" - Marsaglia & Tsang
+ /// ACM Transactions on Mathematical Software, Vol. 26, No. 3, September 2000, Pages 363–372.
+ ///
+ /// The random number generator to use.
+ /// The shape of the Gamma distribution.
+ /// The inverse scale of the Gamma distribution.
+ /// A sample from a Gamma distributed random variable.
+ internal static double SampleGamma(System.Random rnd, double shape, double invScale)
+ {
+ if (Double.IsPositiveInfinity(invScale))
+ {
+ return shape;
+ }
+ else
+ {
+ double a = shape;
+ double alphafix = 1.0;
+
+ // Fix when alpha is less than one.
+ if (shape < 1.0)
+ {
+ a = shape + 1.0;
+ alphafix = System.Math.Pow(rnd.NextDouble(), 1.0 / shape);
+ }
+
+ double d = a - 1.0 / 3.0;
+ double c = 1.0 / System.Math.Sqrt(9.0 * d);
+ while (true)
+ {
+ double x = Normal.Sample(rnd, 0.0, 1.0);
+ double v = 1.0 + c * x;
+ while (v <= 0.0)
+ {
+ x = Normal.Sample(rnd, 0.0, 1.0);
+ v = 1.0 + c * x;
+ }
+ v = v * v * v;
+ double u = rnd.NextDouble();
+ x = x * x;
+ if (u < 1.0 - 0.0331 * x * x)
+ {
+ return alphafix * d * v / invScale;
+ }
+ if (System.Math.Log(u) < 0.5 * x + d * (1.0 - v + System.Math.Log(v)))
+ {
+ return alphafix * d * v / invScale;
+ }
+ }
+ }
+ }
+ }
+}
diff --git a/src/Managed/Managed.csproj b/src/Managed/Managed.csproj
index e7f69772..069bd8f8 100644
--- a/src/Managed/Managed.csproj
+++ b/src/Managed/Managed.csproj
@@ -48,7 +48,9 @@
+
+
diff --git a/src/Managed/SpecialFunctions.cs b/src/Managed/SpecialFunctions.cs
index d8bcc487..76e1e74e 100644
--- a/src/Managed/SpecialFunctions.cs
+++ b/src/Managed/SpecialFunctions.cs
@@ -58,5 +58,37 @@ namespace MathNet.Numerics
return 0d;
}
+
+
+ public static double BetaLn(double a, double b)
+ {
+ return Double.NaN;
+ }
+
+
+ public static double BetaRegularized(double a, double b, double x)
+ {
+ return Double.NaN;
+ }
+
+ public static double DiGamma(double x)
+ {
+ return Double.NaN;
+ }
+
+ public static double Gamma(double x)
+ {
+ return Double.NaN;
+ }
+
+ public static double GammaLn(double x)
+ {
+ return Double.NaN;
+ }
+
+ public static double IncompleteGamma(double x, double z, bool reg)
+ {
+ return Double.NaN;
+ }
}
}
diff --git a/src/Native.UnitTests/Native.UnitTests.csproj b/src/Native.UnitTests/Native.UnitTests.csproj
index ef565cd1..214689f2 100644
--- a/src/Native.UnitTests/Native.UnitTests.csproj
+++ b/src/Native.UnitTests/Native.UnitTests.csproj
@@ -68,9 +68,15 @@
ComplexTests\ComplexTest.cs
+
+ DistributionTests\Continuous\BetaTests.cs
+
DistributionTests\Continuous\ContinuousUniformTests.cs
+
+ DistributionTests\Continuous\GammaTests.cs
+
DistributionTests\Continuous\NormalTests.cs
diff --git a/src/Native/Native.csproj b/src/Native/Native.csproj
index 941b2ce6..d8d5ab04 100644
--- a/src/Native/Native.csproj
+++ b/src/Native/Native.csproj
@@ -53,9 +53,15 @@
Control.cs
+
+ Distributions\Continuous\Beta.cs
+
Distributions\Continuous\ContinuousUniform.cs
+
+ Distributions\Continuous\Gamma.cs
+
Distributions\Continuous\Normal.cs