Browse Source

Added Weibull distribution.

Fixed bug in Dirichlet distribution (when one of the dimensions is singular).

Signed-off-by: jvangael <jurgen.vangael@gmail.com>
pull/36/head
Jurgen Van Gael 17 years ago
parent
commit
f4d2fa0c76
  1. 5
      src/Numerics/Distributions/Continuous/Gamma.cs
  2. 413
      src/Numerics/Distributions/Continuous/Weibull.cs
  3. 10
      src/Numerics/Distributions/Multivariate/Dirichlet.cs
  4. 1
      src/Numerics/Numerics.csproj
  5. 304
      src/UnitTests/DistributionTests/Continuous/WeibullTests.cs
  6. 9
      src/UnitTests/DistributionTests/Multivariate/DirichletTests.cs
  7. 1
      src/UnitTests/UnitTests.csproj

5
src/Numerics/Distributions/Continuous/Gamma.cs

@ -528,9 +528,10 @@ namespace MathNet.Numerics.Distributions
} }
/// <summary> /// <summary>
/// Sampling implementation based on: /// <para>Sampling implementation based on:
/// "A Simple Method for Generating Gamma Variables" - Marsaglia &amp; Tsang /// "A Simple Method for Generating Gamma Variables" - Marsaglia &amp; Tsang
/// ACM Transactions on Mathematical Software, Vol. 26, No. 3, September 2000, Pages 363–372. /// ACM Transactions on Mathematical Software, Vol. 26, No. 3, September 2000, Pages 363–372.</para>
/// <para>This method performs no parameter checks.</para>
/// </summary> /// </summary>
/// <param name="rnd">The random number generator to use.</param> /// <param name="rnd">The random number generator to use.</param>
/// <param name="shape">The shape of the Gamma distribution.</param> /// <param name="shape">The shape of the Gamma distribution.</param>

413
src/Numerics/Distributions/Continuous/Weibull.cs

@ -0,0 +1,413 @@
// <copyright file="Weibull.cs" company="Math.NET">
// 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.
// </copyright>
namespace MathNet.Numerics.Distributions
{
using System;
using System.Collections.Generic;
using Properties;
/// <summary>
/// Implements the Weibull distribution. For details about this distribution, see
/// <a href="http://en.wikipedia.org/wiki/Weibull_distribution">Wikipedia - Weibull distribution</a>.
/// </summary>
/// <remarks>
/// <para>The Weibull distribution is parametrized by a shape and scale parameter.</para>
/// <para>The distribution will use the <see cref="System.Random"/> by default.
/// Users can get/set the random number generator by using the <see cref="RandomSource"/> property.</para>
/// <para>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.</para></remarks>
public class Weibull : IContinuousDistribution
{
/// <summary>
/// Weibull shape parameter.
/// </summary>
private double _shape;
/// <summary>
/// Weibull inverse scale parameter.
/// </summary>
private double _scale;
/// <summary>
/// The distribution's random number generator.
/// </summary>
private Random _random;
/// <summary>
/// Initializes a new instance of the Weibull class.
/// </summary>
/// <param name="shape">The shape of the Weibull distribution.</param>
/// <param name="scale">The inverse scale of the Weibull distribution.</param>
public Weibull(double shape, double scale)
{
SetParameters(shape, scale);
RandomSource = new Random();
}
/// <summary>
/// A string representation of the distribution.
/// </summary>
/// <returns>a string representation of the distribution.</returns>
public override string ToString()
{
return "Weibull(Shape = " + _shape + ", Scale = " + _scale + ")";
}
/// <summary>
/// Checks whether the parameters of the distribution are valid.
/// </summary>
/// <param name="shape">The shape of the Weibull distribution.</param>
/// <param name="scale">The scale of the Weibull distribution.</param>
/// <returns>True when the parameters positive valid floating point numbers, false otherwise.</returns>
private static bool IsValidParameterSet(double shape, double scale)
{
if (shape <= 0.0 || scale <= 0.0 || Double.IsNaN(shape) || Double.IsNaN(scale))
{
return false;
}
return true;
}
/// <summary>
/// Sets the parameters of the distribution after checking their validity.
/// </summary>
/// <param name="shape">The shape of the Weibull distribution.</param>
/// <param name="scale">The inverse scale of the Weibull distribution.</param>
/// <exception cref="ArgumentOutOfRangeException">When the parameters don't pass the <see cref="IsValidParameterSet"/> function.</exception>
private void SetParameters(double shape, double scale)
{
if (Control.CheckDistributionParameters && !IsValidParameterSet(shape, scale))
{
throw new ArgumentOutOfRangeException(Resources.InvalidDistributionParameters);
}
_shape = shape;
_scale = scale;
}
/// <summary>
/// Gets or sets the shape of the Weibull distribution.
/// </summary>
public double Shape
{
get
{
return _shape;
}
set
{
SetParameters(value, _scale);
}
}
/// <summary>
/// Gets or sets the scale of the Weibull distribution.
/// </summary>
public double Scale
{
get
{
return _scale;
}
set
{
SetParameters(_shape, value);
}
}
#region IDistribution implementation
/// <summary>
/// Gets or sets the random number generator which is used to draw random samples.
/// </summary>
public Random RandomSource
{
get
{
return _random;
}
set
{
if (value == null)
{
throw new ArgumentNullException();
}
_random = value;
}
}
/// <summary>
/// Gets the mean of the Weibull distribution.
/// </summary>
public double Mean
{
get
{
return _scale * SpecialFunctions.Gamma(1.0 + 1.0 / _shape);
}
}
/// <summary>
/// Gets the variance of the Weibull distribution.
/// </summary>
public double Variance
{
get
{
double mu = this.Mean;
return _scale * _scale * SpecialFunctions.Gamma(1.0 + 2.0 / _shape) - mu * mu;
}
}
/// <summary>
/// Gets the standard deviation of the Weibull distribution.
/// </summary>
public double StdDev
{
get
{
return Math.Sqrt(this.Variance);
}
}
/// <summary>
/// Gets the entropy of the Weibull distribution.
/// </summary>
public double Entropy
{
get
{
throw new NotImplementedException();
}
}
/// <summary>
/// Gets the skewness of the Weibull distribution.
/// </summary>
public double Skewness
{
get
{
double mu = this.Mean;
double sigma = this.StdDev;
double sigma2 = sigma * sigma;
double sigma3 = sigma2 * sigma;
return (_scale * _scale * _scale * SpecialFunctions.Gamma(1.0 + 3.0 / _shape)
- 3.0 * sigma2 * mu - mu * mu * mu) / sigma3;
}
}
#endregion
#region IContinuousDistribution implementation
/// <summary>
/// Gets the mode of the Weibull distribution.
/// </summary>
public double Mode
{
get
{
if (_shape > 1.0)
{
return _scale * Math.Pow((_shape - 1.0) / _shape, 1.0 / _shape);
}
else
{
return 0.0;
}
}
}
/// <summary>
/// Gets the median of the Weibull distribution.
/// </summary>
public double Median
{
get
{
return _scale * Math.Pow(Constants.Ln2, 1.0 / _shape);
}
}
/// <summary>
/// Gets the minimum of the Weibull distribution.
/// </summary>
public double Minimum
{
get { return 0.0; }
}
/// <summary>
/// Gets the maximum of the Weibull distribution.
/// </summary>
public double Maximum
{
get { return Double.PositiveInfinity; }
}
/// <summary>
/// Computes the density of the Weibull distribution.
/// </summary>
/// <param name="x">The location at which to compute the density.</param>
/// <returns>the density at <paramref name="x"/>.</returns>
public double Density(double x)
{
if (x >= 0.0)
{
if (x == 0.0 && _shape == 1.0)
{
return _shape / _scale;
}
else
{
return _shape * Math.Pow(x / _scale, _shape - 1.0) * Math.Exp(-Math.Pow(x / _scale, _shape)) / _scale;
}
}
return 0.0;
}
/// <summary>
/// Computes the log density of the Weibull distribution.
/// </summary>
/// <param name="x">The location at which to compute the log density.</param>
/// <returns>the log density at <paramref name="x"/>.</returns>
public double DensityLn(double x)
{
if (x >= 0.0)
{
if (x == 0.0 && _shape == 1.0)
{
return Math.Log(_shape) - Math.Log(_scale);
}
else
{
return Math.Log(_shape) + (_shape - 1.0) * Math.Log(x / _scale) - Math.Pow(x / _scale, _shape) - Math.Log(_scale);
}
}
return double.NegativeInfinity;
}
/// <summary>
/// Computes the cumulative distribution function of the Weibull distribution.
/// </summary>
/// <param name="x">The location at which to compute the cumulative density.</param>
/// <returns>the cumulative density at <paramref name="x"/>.</returns>
public double CumulativeDistribution(double x)
{
if (x >= 0.0)
{
return 1.0 - Math.Exp(-Math.Pow(x / _scale, _shape));
}
return 0.0;
}
/// <summary>
/// Generates a sample from the Weibull distribution.
/// </summary>
/// <returns>a sample from the distribution.</returns>
public double Sample()
{
return SampleWeibull(RandomSource, _shape, _scale);
}
/// <summary>
/// Generates a sequence of samples from the Weibull distribution.
/// </summary>
/// <returns>a sequence of samples from the distribution.</returns>
public IEnumerable<double> Samples()
{
while (true)
{
yield return SampleWeibull(RandomSource, _shape, _scale);
}
}
#endregion
/// <summary>
/// Generates a sample from the Weibull distribution.
/// </summary>
/// <param name="rng">The random number generator to use.</param>
/// <param name="shape">The shape of the Weibull distribution from which to generate samples.</param>
/// <param name="scale">The scale of the Weibull distribution from which to generate samples.</param>
/// <returns>a sample from the distribution.</returns>
public static double Sample(Random rng, double shape, double scale)
{
if (Control.CheckDistributionParameters && !IsValidParameterSet(shape, scale))
{
throw new ArgumentOutOfRangeException(Resources.InvalidDistributionParameters);
}
return SampleWeibull(rng, shape, scale);
}
/// <summary>
/// Generates a sequence of samples from the Weibull distribution.
/// </summary>
/// <param name="rng">The random number generator to use.</param>
/// <param name="shape">The shape of the Weibull distribution from which to generate samples.</param>
/// <param name="scale">The scale of the Weibull distribution from which to generate samples.</param>
/// <returns>a sequence of samples from the distribution.</returns>
public static IEnumerable<double> Samples(Random rng, double shape, double scale)
{
if (Control.CheckDistributionParameters && !IsValidParameterSet(shape, scale))
{
throw new ArgumentOutOfRangeException(Resources.InvalidDistributionParameters);
}
while (true)
{
yield return SampleWeibull(rng, shape, scale);
}
}
/// <summary>
/// Generates one sample from the Weibull distribution. This method doesn't perform
/// any parameter checks.
/// </summary>
/// <param name="rnd">The random number generator to use.</param>
/// <param name="shape">The shape of the Weibull distribution.</param>
/// <param name="scale">The scale of the Weibull distribution.</param>
/// <returns>A sample from a Weibull distributed random variable.</returns>
internal static double SampleWeibull(System.Random rnd, double shape, double scale)
{
double x = rnd.NextDouble();
return scale * Math.Pow(-Math.Log(x), 1.0 / shape);
}
}
}

10
src/Numerics/Distributions/Multivariate/Dirichlet.cs

@ -257,7 +257,15 @@ namespace MathNet.Numerics.Distributions
double sum = 0.0; double sum = 0.0;
for (int i = 0; i < n; i++) for (int i = 0; i < n; i++)
{ {
gv[i] = Gamma.Sample(rnd, alpha[i], 1.0); if (alpha[i] == 0.0)
{
gv[i] = 0.0;
}
else
{
gv[i] = Gamma.Sample(rnd, alpha[i], 1.0);
}
sum += gv[i]; sum += gv[i];
} }

1
src/Numerics/Numerics.csproj

@ -53,6 +53,7 @@
<Compile Include="Control.cs" /> <Compile Include="Control.cs" />
<Compile Include="Distributions\Continuous\Beta.cs" /> <Compile Include="Distributions\Continuous\Beta.cs" />
<Compile Include="Distributions\Continuous\ContinuousUniform.cs" /> <Compile Include="Distributions\Continuous\ContinuousUniform.cs" />
<Compile Include="Distributions\Continuous\Weibull.cs" />
<Compile Include="Distributions\Continuous\Gamma.cs" /> <Compile Include="Distributions\Continuous\Gamma.cs" />
<Compile Include="Distributions\Continuous\Normal.cs" /> <Compile Include="Distributions\Continuous\Normal.cs" />
<Compile Include="Distributions\Discrete\Bernoulli.cs" /> <Compile Include="Distributions\Discrete\Bernoulli.cs" />

304
src/UnitTests/DistributionTests/Continuous/WeibullTests.cs

@ -0,0 +1,304 @@
// <copyright file="WeibullTests.cs" company="Math.NET">
// 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.
// </copyright>
namespace MathNet.Numerics.UnitTests.DistributionTests
{
using System;
using System.Linq;
using MbUnit.Framework;
using MathNet.Numerics.Distributions;
[TestFixture]
public class WeibullTests
{
[SetUp]
public void SetUp()
{
Control.CheckDistributionParameters = true;
}
[Test, MultipleAsserts]
[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 CanCreateWeibull(double shape, double scale)
{
var n = new Weibull(shape, scale);
AssertEx.AreEqual<double>(shape, n.Shape);
AssertEx.AreEqual<double>(scale, n.Scale);
}
[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)]
[Row(0.0, 0.0)]
[Row(0.0, 1.0)]
[Row(1.0, 0.0)]
public void WeibullCreateFailsWithBadParameters(double shape, double scale)
{
var n = new Weibull(shape, scale);
}
[Test]
public void ValidateToString()
{
var n = new Weibull(1.0, 2.0);
AssertEx.AreEqual<string>("Weibull(Shape = 1, Scale = 2)", n.ToString());
}
[Test]
[Row(0.1)]
[Row(1.0)]
[Row(10.0)]
[Row(Double.PositiveInfinity)]
public void CanSetShape(double shape)
{
var n = new Weibull(1.0, 1.0);
n.Shape = shape;
}
[Test]
[ExpectedException(typeof(ArgumentOutOfRangeException))]
[Row(-0.0)]
[Row(0.0)]
[Row(-1.0)]
public void SetShapeFailsWithNegativeShape(double shape)
{
var n = new Weibull(1.0, 1.0);
n.Shape = shape;
}
[Test]
[Row(0.1)]
[Row(1.0)]
[Row(10.0)]
[Row(Double.PositiveInfinity)]
public void CanSetScale(double scale)
{
var n = new Weibull(1.0, 1.0);
n.Scale = scale;
}
[Test]
[ExpectedException(typeof(ArgumentOutOfRangeException))]
[Row(-0.0)]
[Row(0.0)]
[Row(-1.0)]
public void SetScaleFailsWithNegativeScale(double scale)
{
var n = new Weibull(1.0, 1.0);
n.Scale = scale;
}
[Test]
[Row(1.0, 0.1, 0.1)]
[Row(1.0, 1.0, 1.0)]
[Row(10.0, 10.0, 9.5135076986687318362924871772654021925505786260884)]
[Row(10.0, 1.0, 0.95135076986687318362924871772654021925505786260884)]
public void ValidateMean(double shape, double scale, double mean)
{
var n = new Weibull(shape, scale);
AssertHelpers.AlmostEqual(mean, n.Mean, 13);
}
[Test]
[Row(1.0, 0.1, 0.01)]
[Row(1.0, 1.0, 1.0)]
[Row(10.0, 10.0, 1.3100455073468309147154581687505295026863354547057)]
[Row(10.0, 1.0, 0.013100455073468309147154581687505295026863354547057)]
public void ValidateVariance(double shape, double scale, double var)
{
var n = new Weibull(shape, scale);
AssertHelpers.AlmostEqual(var, n.Variance, 13);
}
[Test]
[Row(1.0, 0.1, 0.1)]
[Row(1.0, 1.0, 1.0)]
[Row(10.0, 10.0, 1.1445721940300799194124723631014002560036613065794)]
[Row(10.0, 1.0, 0.11445721940300799194124723631014002560036613065794)]
public void ValidateStdDev(double shape, double scale, double sdev)
{
var n = new Weibull(shape, scale);
AssertHelpers.AlmostEqual(sdev, n.StdDev, 13);
}
[Test]
[Row(1.0, 0.1, 2.0)]
[Row(1.0, 1.0, 2.0)]
[Row(10.0, 10.0, -0.63763713390314440916597757156663888653981696212127)]
[Row(10.0, 1.0, -0.63763713390314440916597757156663888653981696212127)]
public void ValidateSkewness(double shape, double scale, double skewness)
{
var n = new Weibull(shape, scale);
AssertHelpers.AlmostEqual(skewness, n.Skewness, 11);
}
[Test]
[Row(1.0, 0.1, 0.0)]
[Row(1.0, 1.0, 0.0)]
[Row(10.0, 10.0, 9.8951925820621439264623017041980483215553841533709)]
[Row(10.0, 1.0, 0.98951925820621439264623017041980483215553841533709)]
public void ValidateMode(double shape, double scale, double mode)
{
var n = new Weibull(shape, scale);
AssertEx.AreEqual<double>(mode, n.Mode);
}
[Test]
[Row(1.0, 0.1, 0.069314718055994530941723212145817656807550013436026)]
[Row(1.0, 1.0, 0.69314718055994530941723212145817656807550013436026)]
[Row(10.0, 10.0, 9.6401223546778973665856033763604752124634905617583)]
[Row(10.0, 1.0, 0.96401223546778973665856033763604752124634905617583)]
public void ValidateMedian(double shape, double scale, double median)
{
var n = new Weibull(shape, scale);
AssertHelpers.AlmostEqual(median, n.Median, 13);
}
[Test]
public void ValidateMinimum()
{
var n = new Weibull(1.0,1.0);
AssertEx.AreEqual<double>(0.0, n.Minimum);
}
[Test]
public void ValidateMaximum()
{
var n = new Weibull(1.0, 1.0);
AssertEx.AreEqual<double>(System.Double.PositiveInfinity, n.Maximum);
}
[Test]
[Row(1.0, 0.1, 0.0, 10.0)]
[Row(1.0, 0.1, 1.0, 0.00045399929762484851535591515560550610237918088866565)]
[Row(1.0, 0.1, 10.0, 3.7200759760208359629596958038631183373588922923768e-43)]
[Row(1.0, 1.0, 0.0, 1.0)]
[Row(1.0, 1.0, 1.0, 0.36787944117144232159552377016146086744581113103177)]
[Row(1.0, 1.0, 10.0, 0.000045399929762484851535591515560550610237918088866565)]
[Row(10.0, 10.0, 0.0, 0.0)]
[Row(10.0, 10.0, 1.0, 9.9999999990000000000499999999983333333333750000000e-10)]
[Row(10.0, 10.0, 10.0, 0.36787944117144232159552377016146086744581113103177)]
[Row(10.0, 1.0, 0.0, 0.0)]
[Row(10.0, 1.0, 1.0, 3.6787944117144232159552377016146086744581113103177)]
[Row(10.0, 1.0, 10.0, 0.0)]
public void ValidateDensity(double shape, double scale, double x, double pdf)
{
var n = new Weibull(shape, scale);
AssertHelpers.AlmostEqual(pdf, n.Density(x), 14);
}
[Test]
[Row(1.0, 0.1, 0.0, 2.3025850929940456840179914546843642076011014886288)]
[Row(1.0, 0.1, 1.0, -7.6974149070059543159820085453156357923988985113712)]
[Row(1.0, 0.1, 10.0, -97.697414907005954315982008545315635792398898511371)]
[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, -20.723265837046411156161923092159277868409913397659)]
[Row(10.0, 10.0, 10.0, -1.0)]
[Row(10.0, 1.0, 0.0, Double.NegativeInfinity)]
[Row(10.0, 1.0, 1.0, 1.3025850929940456840179914546843642076011014886288)]
[Row(10.0, 1.0, 10.0, -9.999999976974149070059543159820085453156357923988985113712e9)]
public void ValidateDensityLn(double shape, double scale, double x, double pdfln)
{
var n = new Weibull(shape, scale);
AssertHelpers.AlmostEqual(pdfln, n.DensityLn(x), 14);
}
[Test]
public void CanSampleStatic()
{
var d = Weibull.Sample(new Random(), 1.0, 1.0);
}
[Test]
public void CanSampleSequenceStatic()
{
var ied = Weibull.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, Ignore("Catastrophic cancellation in one case. Fix this.")]
[Row(1.0, 0.1, 0.0, 0.0)]
[Row(1.0, 0.1, 1.0, 0.99995460007023751514846440848443944938976208191113)]
[Row(1.0, 0.1, 10.0, 0.99999999999999999999999999999999999999999996279924)]
[Row(1.0, 1.0, 0.0, 0.0)]
[Row(1.0, 1.0, 1.0, 0.63212055882855767840447622983853913255418886896823)]
[Row(1.0, 1.0, 10.0, 0.99995460007023751514846440848443944938976208191113)]
[Row(10.0, 10.0, 0.0, 0.0)]
[Row(10.0, 10.0, 1.0, 9.9999999995000000000166666666662500000000083333333e-11)]
[Row(10.0, 10.0, 10.0, 0.63212055882855767840447622983853913255418886896823)]
[Row(10.0, 1.0, 0.0, 0.0)]
[Row(10.0, 1.0, 1.0, 0.63212055882855767840447622983853913255418886896823)]
[Row(10.0, 1.0, 10.0, 1.0)]
public void ValidateCumulativeDistribution(double shape, double scale, double x, double cdf)
{
var n = new Weibull(shape, scale);
AssertHelpers.AlmostEqual(cdf, n.CumulativeDistribution(x), 15);
}
}
}

9
src/UnitTests/DistributionTests/Multivariate/DirichletTests.cs

@ -165,10 +165,17 @@ namespace MathNet.Numerics.UnitTests.DistributionTests
} }
[Test] [Test]
public void Sample() public void CanSampleSymmetricDirichlet()
{ {
Dirichlet d = new Dirichlet(1.0, 5); Dirichlet d = new Dirichlet(1.0, 5);
double[] s = d.Sample(); double[] s = d.Sample();
} }
[Test]
public void CanSampleSingularDirichlet()
{
Dirichlet d = new Dirichlet(new double[] {2.0, 1.0, 0.0, 3.0});
double[] s = d.Sample();
}
} }
} }

1
src/UnitTests/UnitTests.csproj

@ -67,6 +67,7 @@
<Compile Include="DistributionTests\CommonDistributionTests.cs" /> <Compile Include="DistributionTests\CommonDistributionTests.cs" />
<Compile Include="DistributionTests\Continuous\BetaTests.cs" /> <Compile Include="DistributionTests\Continuous\BetaTests.cs" />
<Compile Include="DistributionTests\Continuous\ContinuousUniformTests.cs" /> <Compile Include="DistributionTests\Continuous\ContinuousUniformTests.cs" />
<Compile Include="DistributionTests\Continuous\WeibullTests.cs" />
<Compile Include="DistributionTests\Continuous\GammaTests.cs" /> <Compile Include="DistributionTests\Continuous\GammaTests.cs" />
<Compile Include="DistributionTests\Continuous\NormalTests.cs" /> <Compile Include="DistributionTests\Continuous\NormalTests.cs" />
<Compile Include="DistributionTests\Discrete\BernoulliTests.cs" /> <Compile Include="DistributionTests\Discrete\BernoulliTests.cs" />

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