Added extension methods for System.Random that sample additional value types.

Signed-off-by: jvangael <jurgen.vangael@gmail.com>

src/Numerics/Numerics.csproj

@@ -100,6 +100,7 @@
       <DesignTime>True</DesignTime>
       <DependentUpon>Resources.resx</DependentUpon>
     </Compile>
+    <Compile Include="Random\SystemRandomExtensions.cs" />
     <Compile Include="Sampling\Sample.Random.cs" />
     <Compile Include="Sampling\Sample.Chebyshev.cs" />
     <Compile Include="Sampling\Sample.Equidistant.cs" />

src/Numerics/Random/SystemRandomExtensions.cs

@@ -0,0 +1,117 @@
+// <copyright file="SystemRandomExtensions.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.Random
+{
+    using System;
+    using System.Collections.Generic;
+    using Properties;
+
+    public static class SystemRandomExtensions
+    {
+        /// <summary>
+        /// Returns a nonnegative random number less than <see cref="Int64.MaxValue"/>.
+        /// </summary>
+        /// <returns>
+        /// A 64-bit signed integer greater than or equal to 0, and less than <see cref="Int64.MaxValue"/>; that is, 
+        /// the range of return values includes 0 but not <paramref name="Int64.MaxValue"/>.
+        /// </returns>
+        /// <seealso cref="NextFullRangeInt64()"/>
+        public static long NextInt64(this System.Random rnd)
+        {
+            byte[] buffer = new byte[sizeof(Int64)];
+            rnd.NextBytes(buffer);
+            long candidate = BitConverter.ToInt64(buffer, 0);
+
+            // wrap negative numbers around, mapping every negative number to a distinct nonnegative number
+            // MinValue -> 0, -1 -> MaxValue
+            candidate &= Int64.MaxValue;
+
+            // skip candidate if it is MaxValue. Recursive since rare.
+            return (candidate == Int64.MaxValue) ? rnd.NextInt64() : candidate;
+        }
+
+        /// <summary>
+        /// Returns a random number of the full Int32 range.
+        /// </summary>
+        /// <returns>
+        /// A 32-bit signed integer of the full range, including 0, negative numbers,
+        /// <see cref="Int32.MaxValue"/> and <see cref="Int32.MinValue"/>.
+        /// </returns>
+        /// <seealso cref="Next()"/>
+        public static int NextFullRangeInt32(this System.Random rnd)
+        {
+            byte[] buffer = new byte[sizeof(Int32)];
+            rnd.NextBytes(buffer);
+            return BitConverter.ToInt32(buffer, 0);
+        }
+
+        /// <summary>
+        /// Returns a random number of the full Int64 range.
+        /// </summary>
+        /// <returns>
+        /// A 64-bit signed integer of the full range, including 0, negative numbers,
+        /// <see cref="Int64.MaxValue"/> and <see cref="Int64.MinValue"/>.
+        /// </returns>
+        /// <seealso cref="NextInt64()"/>
+        public static long NextFullRangeInt64(this System.Random rnd)
+        {
+            byte[] buffer = new byte[sizeof(Int64)];
+            rnd.NextBytes(buffer);
+            return BitConverter.ToInt64(buffer, 0);
+        }
+
+        /// <summary>
+        /// Returns a nonnegative decimal floating point random number less than 1.0.
+        /// </summary>
+        /// <returns>
+        /// A decimal floating point number greater than or equal to 0.0, and less than 1.0; that is, 
+        /// the range of return values includes 0.0 but not 1.0.
+        /// </returns>
+        public static decimal NextDecimal(this System.Random rnd)
+        {
+            decimal candidate;
+
+            // 50.049 % chance that the number is below 1.0. Try until we have one.
+            // Guarantees that any decimal in the interval can
+            // indeed be reached, with uniform probability.
+            do
+            {
+                candidate = new Decimal(
+                    rnd.NextFullRangeInt32(),
+                    rnd.NextFullRangeInt32(),
+                    rnd.NextFullRangeInt32(),
+                    false,
+                    28);
+            }
+            while (candidate >= 1.0m);
+
+            return candidate;
+        }
+    }
+}

src/UnitTests/Random/SystemRandomExtensionTests.cs

@@ -0,0 +1,65 @@
+// <copyright file="SystemRandomExtensionTests.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 MbUnit.Framework;
+    using MathNet.Numerics.Random;
+
+    [TestFixture]
+    public class SystemRandomExtensionTests
+    {
+        [Test]
+        public void CanSampleInt64()
+        {
+            var rnd = new System.Random();
+            long l = rnd.NextInt64();
+        }
+
+        [Test]
+        public void CanSampleFullRangeInt32()
+        {
+            var rnd = new System.Random();
+            int l = rnd.NextFullRangeInt32();
+        }
+
+        [Test]
+        public void CanSampleFullRangeInt64()
+        {
+            var rnd = new System.Random();
+            long l = rnd.NextFullRangeInt64();
+        }
+
+        [Test]
+        public void CanSampleDecimal()
+        {
+            var rnd = new System.Random();
+            decimal l = rnd.NextDecimal();
+        }
+    }
+}

src/UnitTests/UnitTests.csproj

@@ -92,6 +92,7 @@
     <Compile Include="NumberTheoryTests\IntegerTheoryTest.cs" />
     <Compile Include="PrecisionTest.cs" />
     <Compile Include="Properties\AssemblyInfo.cs" />
+    <Compile Include="Random\SystemRandomExtensionTests.cs" />
     <Compile Include="SortingTests.cs" />
     <Compile Include="SpecialFunctionsTests\ErfTests.cs" />
     <Compile Include="SpecialFunctionsTests\FactorialTest.cs" />