Inspection fixes and optimizations.

Author: Oren (electricessence)

DynamicArithmetic.cs

@@ -50,9 +50,10 @@ public static T PowerOf<T>(this T a, uint power)
 			var result = a;
 
 			for (uint i = 1; i < power; i++)
+				// ReSharper disable once RedundantCast
 				result *= (dynamic)a;
 
-			return a;
+			return result;
 		}
 
 

MathExtensions.cs

@@ -5,6 +5,7 @@
 
 using System;
 using System.Collections.Generic;
+using System.Diagnostics.Contracts;
 
 namespace Open.Arithmetic
 {
@@ -14,51 +15,72 @@ public static class MathExtensions
 		static void ValidateIntPower(int power)
 		{
 			if (power < 0)
-				throw new ArgumentOutOfRangeException(nameof(power), power, "In order to maintain the interger math, power cannot be negative.");
+				throw new ArgumentOutOfRangeException(nameof(power), power,
+					"In order to maintain the interger math, power cannot be negative.");
 		}
 
 		/// <summary>
 		/// Raise a number to the power of another.  Uses integer math only.
 		/// </summary>
-		/// <param name="value"></param>
-		/// <param name="power"></param>
+		/// <param name="base">The value to multiply.</param>
+		/// <param name="power">The number of times to multiply by.</param>
 		/// <returns>The value to the power.</returns>
-		public static int PowerOf(this int value, int power)
+		public static int PowerOf(this int @base, int power)
 		{
 			ValidateIntPower(power);
 
-			if (value == 0 || value == 1)
-				return value;
+			var result = 1;
+			while (power != 0)
+			{
+				if ((power & 1) == 1)
+					result *= @base;
+				power >>= 1;
+				@base *= @base;
+			}
 
-			if (value == -1)
-				return power % 2 == 0 ? 1 : -1;
+			return result;
+		}
 
-			var v = 1;
-			for (var i = 1; i < power; i++)
-				v *= value;
-			return v;
+		/// <summary>
+		/// Raise a number to the power of another.  Uses integer math only.
+		/// </summary>
+		/// <param name="base">The value to multiply.</param>
+		/// <param name="power">The number of times to multiply by.</param>
+		/// <returns>The value to the power.</returns>
+		public static ulong PowerOf(this ulong @base, int power)
+		{
+			ulong result = 1;
+			while (power != 0)
+			{
+				if ((power & 1) == 1)
+					result *= @base;
+				power >>= 1;
+				@base *= @base;
+			}
+
+			return result;
 		}
 
 		/// <summary>
 		/// Raise a number to the power of another.  Uses integer math only.
 		/// </summary>
-		/// <param name="value"></param>
-		/// <param name="power"></param>
+		/// <param name="base">The value to multiply.</param>
+		/// <param name="power">The number of times to multiply by.</param>
 		/// <returns>The value to the power.</returns>
-		public static long PowerOf(this long value, int power)
+		public static long PowerOf(this long @base, int power)
 		{
 			ValidateIntPower(power);
 
-			if (value == 0L || value == 1L)
-				return value;
-
-			if (value == -1L)
-				return power % 2 == 0 ? 1L : -1L;
+			long result = 1;
+			while (power != 0)
+			{
+				if ((power & 1) == 1)
+					result *= @base;
+				power >>= 1;
+				@base *= @base;
+			}
 
-			var v = 1L;
-			for (var i = 1; i < power; i++)
-				v *= value;
-			return v;
+			return result;
 		}
 
 		/// <summary>
@@ -69,7 +91,8 @@ public static long PowerOf(this long value, int power)
 		public static int AsInteger(this bool[] source)
 		{
 			if (source == null) throw new NullReferenceException();
-			if (source.Length > 32) throw new ArgumentOutOfRangeException("Array cannot be greater than 32 bits.");
+			if (source.Length > 32) throw new ArgumentOutOfRangeException(nameof(source), source, "Array cannot be greater than 32 bits.");
+			Contract.EndContractBlock();
 
 			var result = 0;
 
@@ -81,14 +104,15 @@ public static int AsInteger(this bool[] source)
 		}
 
 		/// <summary>
-		/// Converts a set of booleans (0|1) to a 32 bit integer.
+		/// Converts a set of booleans (0|1) to a 64 bit integer.
 		/// </summary>
-		/// <param name="source">A array of 32 booleans or less.</param>
-		/// <returns>32 bit integer</returns>
+		/// <param name="source">A array of 64 booleans or less.</param>
+		/// <returns>64 bit integer</returns>
 		public static long AsLong(this bool[] source)
 		{
 			if (source == null) throw new NullReferenceException();
-			if (source.Length > 64) throw new ArgumentOutOfRangeException("Array cannot be greater than 32 bits.");
+			if (source.Length > 64) throw new ArgumentOutOfRangeException(nameof(source), source, "Array cannot be greater than 64 bits.");
+			Contract.EndContractBlock();
 
 			long result = 0;
 
@@ -99,10 +123,18 @@ public static long AsLong(this bool[] source)
 			return result;
 		}
 
-		public static double Product(this IEnumerable<double> source)
+		/// <summary>
+		/// Multiplies a set of numbers together.
+		/// </summary>
+		/// <param name="source">The source enumerable.</param>
+		/// <param name="defaultValueIfNoElements">The value to return if the sequence contains no elements.</param>
+		/// <returns>The resultant product.</returns>
+		public static double Product(this IEnumerable<double> source,
+			double defaultValueIfNoElements = double.NaN)
 		{
-
-			if (source == null) throw new NullReferenceException();
+			if (source == null)
+				throw new NullReferenceException();
+			Contract.EndContractBlock();
 
 			var any = false;
 			var result = 1d;
@@ -113,13 +145,24 @@ public static double Product(this IEnumerable<double> source)
 				result *= s;
 			}
 
-			return any ? result : double.NaN;
+			return any ? result : defaultValueIfNoElements;
 		}
 
-		public static double AverageDouble(this IEnumerable<double> source)
+		/// <summary>
+		/// Sums all the values of the sequence and divides by the count of the elements. (The average of the sequence.)
+		/// </summary>
+		/// <param name="source">The source enumerable.</param>
+		/// <param name="defaultValueIfNoElements">The value to return if the sequence contains no elements.</param>
+		/// <returns>The resultant average of the sequence.</returns>
+		public static double AverageDouble(this IEnumerable<double> source,
+			double defaultValueIfNoElements = double.NaN)
 		{
+			if (source == null)
+				throw new NullReferenceException();
+			Contract.EndContractBlock();
+
 			double sum = 0;
-			double count = 0;
+			var count = 0;
 			foreach (var s in source)
 			{
 				if (double.IsNaN(s))
@@ -129,28 +172,40 @@ public static double AverageDouble(this IEnumerable<double> source)
 			}
 
 			if (count == 0)
-				return double.NaN;
+				return defaultValueIfNoElements;
 
 			return sum / count;
 		}
 
+		/// <summary>
+		/// Takes the first element in the sequence and divides it by the following elements.
+		/// </summary>
+		/// <param name="source">The source enumerable.</param>
+		/// <returns>The resultant quotiient.</returns>
 		public static double Quotient(this IEnumerable<double> source)
 		{
-			if (source == null) throw new NullReferenceException();
+			if (source == null)
+				throw new NullReferenceException();
+			Contract.EndContractBlock();
 
 			var index = 0;
 			var result = double.NaN;
 			foreach (var s in source)
 			{
 				if (double.IsNaN(s)) return double.NaN;
-				if (index == 0)
-				{
-					if (s == 0) return 0;
-					result = s;
-				}
-				else
+				switch (index)
 				{
-					result /= s;
+					// ReSharper disable once CompareOfFloatsByEqualityOperator
+					case 0 when s == 0:
+						return 0;
+					case 0:
+						result = s;
+						break;
+					default:
+						// ReSharper disable once CompareOfFloatsByEqualityOperator
+						if (s == 0) return double.NaN;
+						result /= s;
+						break;
 				}
 
 				index++;
@@ -159,12 +214,27 @@ public static double Quotient(this IEnumerable<double> source)
 			return result;
 		}
 
+		/// <summary>
+		/// Takes the numerator and divides it by the divisors.
+		/// </summary>
+		/// <param name="divisors">The source enumerable.</param>
+		/// <param name="numerator">The value to divide.</param>
+		/// <returns>The resultant quotient.</returns>
 		public static double QuotientOf(this IEnumerable<double> divisors, double numerator)
 		{
+			if (divisors == null)
+				throw new NullReferenceException();
+			Contract.EndContractBlock();
+
+			// ReSharper disable once CompareOfFloatsByEqualityOperator
+			if (double.IsNaN(numerator) || double.IsInfinity(numerator) || numerator == 0)
+				return numerator;
+
 			var any = false;
 			var result = numerator;
 			foreach (var s in divisors)
 			{
+				// ReSharper disable once CompareOfFloatsByEqualityOperator
 				if (s == 0 || double.IsNaN(s)) return double.NaN;
 				result /= s;
 				any = true;
@@ -173,27 +243,6 @@ public static double QuotientOf(this IEnumerable<double> divisors, double numera
 			return any ? result : double.NaN;
 		}
 
-		public static double Difference(this IEnumerable<double> source)
-		{
-			if (source == null) throw new NullReferenceException();
-
-			var any = false;
-			var result = 0d;
-			foreach (var s in source)
-			{
-				if (double.IsNaN(s)) return double.NaN;
-				if (!any)
-					result = s;
-				else
-					result -= s;
-
-				any = true;
-
-			}
-
-			return any ? result : double.NaN;
-		}
-
 
 	}
 }

Open.Arithmetic.csproj

@@ -15,10 +15,10 @@ Part of the "Open" set of libraries.</Description>
     <RepositoryUrl>https://github.com/electricessence/Open.Arithmetic/</RepositoryUrl>
     <RepositoryType>git</RepositoryType>
     <PackageTags>dotnet, dotnet-core, dotnetcore, cs, math, dynamic, arithmetic, triangular, statistical, variance, covariance, correlation</PackageTags>
-    <Version>1.1.1</Version>
-    <PackageReleaseNotes>Extends Triangular methods and added TriangularIndexer.</PackageReleaseNotes>
-    <AssemblyVersion>1.1.1.0</AssemblyVersion>
-    <FileVersion>1.1.1.0</FileVersion>
+    <Version>1.2.0</Version>
+    <PackageReleaseNotes>Inspection fixes and optimizations.</PackageReleaseNotes>
+    <AssemblyVersion>1.2.0.0</AssemblyVersion>
+    <FileVersion>1.2.0.0</FileVersion>
   </PropertyGroup>
 
   <PropertyGroup Condition="'$(Configuration)|$(Platform)'=='Release|AnyCPU'">
@@ -37,7 +37,8 @@ Part of the "Open" set of libraries.</Description>
   </ItemGroup>
 
   <ItemGroup>
-    <PackageReference Include="Open.Collections" Version="2.3.0" />
+    <PackageReference Include="Microsoft.CSharp" Version="4.5.0" />
+    <PackageReference Include="Open.Collections" Version="2.4.4" />
   </ItemGroup>
 
 </Project>