Distributions: merge work on Triangular distribution

src/Numerics/Distributions/Triangular.cs

@@ -96,7 +96,9 @@ namespace MathNet.Numerics.Distributions
         /// <exception cref="ArgumentOutOfRangeException">When the parameters are out of range.</exception>
         void SetParameters(double lower, double upper, double mode)
         {
-            if (upper < mode || mode < lower || Double.IsNaN(upper) || Double.IsNaN(lower) || Double.IsNaN(mode))
+            if (upper < mode || mode < lower || Double.IsNaN(upper) || Double.IsNaN(lower) || Double.IsNaN(mode)
+                || Double.IsInfinity(upper) || Double.IsInfinity(lower) || Double.IsInfinity(mode)
+                )
             {
                 throw new ArgumentException(Resources.InvalidDistributionParameters);
             }
@@ -388,7 +390,7 @@ namespace MathNet.Numerics.Distributions
         /// <param name="upper">Upper bound. Range: lower ≤ mode ≤ upper</param>
         /// <param name="mode">Mode (most frequent value).  Range: lower ≤ mode ≤ upper</param>
         /// <returns>a sample from the distribution.</returns>
-        public double Sample(System.Random rnd, double lower, double upper, double mode)
+        public static double Sample(System.Random rnd, double lower, double upper, double mode)
         {
             var a = lower;
             var b = upper;
@@ -408,7 +410,7 @@ namespace MathNet.Numerics.Distributions
         /// <param name="upper">Upper bound. Range: lower ≤ mode ≤ upper</param>
         /// <param name="mode">Mode (most frequent value).  Range: lower ≤ mode ≤ upper</param>
         /// <returns>a sequence of samples from the distribution.</returns>
-        public IEnumerable<double> Samples(System.Random rnd, double lower, double upper, double mode)
+        public static IEnumerable<double> Samples(System.Random rnd, double lower, double upper, double mode)
         {
             while (true)
             {
@@ -423,7 +425,7 @@ namespace MathNet.Numerics.Distributions
         /// <param name="upper">Upper bound. Range: lower ≤ mode ≤ upper</param>
         /// <param name="mode">Mode (most frequent value).  Range: lower ≤ mode ≤ upper</param>
         /// <returns>a sample from the distribution.</returns>
-        public double Sample(double lower, double upper, double mode)
+        public static double Sample(double lower, double upper, double mode)
         {
             return Sample(SystemRandomSource.Default, lower, upper, mode);
         }
@@ -435,7 +437,7 @@ namespace MathNet.Numerics.Distributions
         /// <param name="upper">Upper bound. Range: lower ≤ mode ≤ upper</param>
         /// <param name="mode">Mode (most frequent value).  Range: lower ≤ mode ≤ upper</param>
         /// <returns>a sequence of samples from the distribution.</returns>
-        public IEnumerable<double> Samples(double lower, double upper, double mode)
+        public static IEnumerable<double> Samples(double lower, double upper, double mode)
         {
             return Samples(SystemRandomSource.Default, lower, upper, mode);
         }

src/UnitTests/DistributionTests/Continuous/TriangularTests.cs

@@ -0,0 +1,202 @@
+// <copyright file="TriangularTests.cs" company="Math.NET">
+// Math.NET Numerics, part of the Math.NET Project
+// http://numerics.mathdotnet.com
+// http://github.com/mathnet/mathnet-numerics
+// http://mathnetnumerics.codeplex.com
+//
+// Copyright (c) 2009-2014 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>
+
+using System;
+using System.Linq;
+using MathNet.Numerics.Distributions;
+using NUnit.Framework;
+
+namespace MathNet.Numerics.UnitTests.DistributionTests.Continuous
+{
+    using Random = System.Random;
+
+    /// <summary>
+    /// Triangular distribution tests.
+    /// </summary>
+    [TestFixture, Category("Distributions")]
+    public class TriangularTests
+    {
+        /// <summary>
+        /// Can create Triangular distribution.
+        /// </summary>
+        /// <param name="lower">Lower Bound.</param>
+        /// <param name="upper">Upper Bound.</param>
+        /// <param name="mode">Mode.</param>
+        [TestCase(0.0, 0.0, 0.0)]
+        [TestCase(-1.0, 1.0, 0.0)]
+        [TestCase(1.0, 2.0, 1.0)]
+        [TestCase(5.0, 25.0, 25.0)]
+        [TestCase(1.0e-5, 1.0e5, 1.0e-3)]
+        [TestCase(0.0, 1.0, 0.9)]
+        [TestCase(-4.0, -0.5, -2.0)]
+        [TestCase(-13.039, 8.42, 1.17)]
+        public void CanCreateTriangular(double lower, double upper, double mode)
+        {
+            var n = new Triangular(lower, upper, mode);
+            Assert.AreEqual(lower, n.LowerBound);
+            Assert.AreEqual(upper, n.UpperBound);
+            Assert.AreEqual(mode, n.Mode);
+        }
+
+        /// <summary>
+        /// Triangular create fails with bad parameters.
+        /// </summary>
+        [TestCase(0.0, 1.0, -0.1)]
+        [TestCase(0.0, 1.0, 1.1)]
+        [TestCase(0.0, -1.0, 0.5)]
+        [TestCase(2.0, 1.0, 1.5)]
+        [TestCase(Double.NaN, 1.0, 0.5)]
+        [TestCase(0.2, Double.NaN, 0.5)]
+        [TestCase(0.5, 1.0, Double.NaN)]
+        [TestCase(Double.NaN, Double.NaN, Double.NaN)]
+        [TestCase(Double.NegativeInfinity, 1.0, 0.5)]
+        [TestCase(0.0, Double.PositiveInfinity, 0.5)]
+        public void TriangularCreateFailsWithBadParameters(double lower, double upper, double mode)
+        {
+            Assert.That(() => new Triangular(lower, upper, mode), Throws.ArgumentException);
+        }
+
+        /// <summary>
+        /// Validate to string.
+        /// </summary>
+        [Test]
+        public void ValidateToString()
+        {
+            var n = new Triangular(0d, 2d, 1d);
+            Assert.AreEqual("Triangular(Lower = 0, Upper = 2, Mode = 1)", n.ToString());
+        }
+
+        /// <summary>
+        /// Can Set Lower Bound
+        /// </summary>
+        /// <param name="lower">New Lower Bound.</param>
+        [TestCase(-0.0)]
+        [TestCase(0.0)]
+        [TestCase(0.1)]
+        [TestCase(1.0)]
+        [TestCase(10.0)]
+        public void CanSetLowerBound(double lower)
+        {
+            new Triangular(0.0, 20.0, 10.0)
+            {
+                LowerBound = lower
+            };
+        }
+
+        /// <summary>
+        /// Set LowerBound fails if greater than Mode.
+        /// </summary>
+        [TestCase(1.0, 0.5)]
+        [TestCase(Double.PositiveInfinity, 0.5)]
+        public void SetLowerBoundFailsIfGreaterThanMode(double lower, double mode)
+        {
+            var n = new Triangular(0.0, 100.0, mode);
+            Assert.That(() => n.LowerBound = lower, Throws.ArgumentException);
+        }
+
+        // Todo: Add tests for setting upper bound and mode values.
+        
+        // Todo: Add tests for:
+        // - Mean, 
+        // - Entropy, 
+        // - Skewness, 
+        // - Mode (note: Mode is an input parameter for this distribution),
+        // - Median
+        // - Minimum (should be the same as LowerBound)
+        // - Maximum (should be the same as UpperBound)
+
+        /// <summary>
+        /// Can sample static.
+        /// </summary>
+        [Test]
+        public void CanSampleStatic()
+        {
+            Triangular.Sample(new Random(0), 2.0, 3.0, 2.5);
+            Triangular.Sample(10.0, 100.0, 30.0);
+        }
+
+        /// <summary>
+        /// Can sample sequence static.
+        /// </summary>
+        [Test]
+        public void CanSampleSequenceStatic()
+        {
+            var ied = Triangular.Samples(new Random(0), 2.0, 3.0, 2.5);
+            ied.Take(5).ToArray();
+            ied = Triangular.Samples(10.0, 100.0, 30.0);
+            ied.Take(5).ToArray();
+        }
+
+        /// <summary>
+        /// Fail sample static with wrong parameters.
+        /// </summary>
+        [Test]
+        public void FailSampleStatic()
+        {
+            Assert.That(() => Triangular.Sample(new Random(0), 1.0, -1.0, 0.1), Throws.ArgumentException);
+        }
+
+        /// <summary>
+        /// Fail sample sequence static with wrong parameters.
+        /// </summary>
+        [Test]
+        public void FailSampleSequenceStatic()
+        {
+            Assert.That(() => Triangular.Samples(new Random(0), 1.0, -1.0, 0.1).First(), Throws.ArgumentException);
+        }
+
+        /// <summary>
+        /// Can sample.
+        /// </summary>
+        [Test]
+        public void CanSample()
+        {
+            var n = new Triangular(0.1, 0.3, 0.2);
+            n.Sample();
+        }
+
+        /// <summary>
+        /// Can sample sequence.
+        /// </summary>
+        [Test]
+        public void CanSampleSequence()
+        {
+            var n = new Triangular(0.1, 0.3, 0.2);
+            var ied = n.Samples();
+            ied.Take(5).ToArray();
+        }
+
+        // Todo: Add tests for:
+        // - Density
+        // - DensityLn
+        // - Cumulative Dist.
+        // - Inverse Cumulative Dist.
+    }
+}

src/UnitTests/UnitTests.csproj

@@ -110,6 +110,7 @@
     <Compile Include="DistributionTests\Continuous\RayleighTests.cs" />
     <Compile Include="DistributionTests\Continuous\StableTests.cs" />
     <Compile Include="DistributionTests\Continuous\StudentTTests.cs" />
+    <Compile Include="DistributionTests\Continuous\TriangularTests.cs" />
     <Compile Include="DistributionTests\Continuous\WeibullTests.cs" />
     <Compile Include="DistributionTests\Discrete\BernoulliTests.cs" />
     <Compile Include="DistributionTests\Discrete\BinomialTests.cs" />