- Fixes Bug #45 - Restore the ability to raise a value to a decimal p…

…ower. - Minor Version Bump
AdamWhiteHat · May 8, 2024 · 8d3de28 · 8d3de28
1 parent 37c6d6e
commit 8d3de28
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Showing 3 changed files with 70 additions and 1 deletion.
diff --git a/BigDecimal/BigDecimal.cs b/BigDecimal/BigDecimal.cs
@@ -852,6 +852,21 @@ private static BigDecimal Pow_Precision(BigDecimal baseValue, BigInteger exponen
 			return result;
 		}
 
+		/// <summary>Returns a specified number raised to the specified power.</summary>
+		public static BigDecimal Pow(Double basis, Double exponent)
+		{
+			var tmp = One;
+			while (Math.Abs(exponent) > ExpChunk)
+			{
+				var diff = exponent > 0 ? ExpChunk : -ExpChunk;
+				tmp *= Math.Pow(basis, diff);
+				exponent -= diff;
+			}
+
+			return tmp * Math.Pow(basis, exponent);
+		}
+		private static double ExpChunk = 2.0d;
+
 		public static BigDecimal SquareRoot(BigDecimal input, Int32 decimalPlaces)
 		{
 			return NthRoot(input, 2, decimalPlaces);

diff --git a/BigDecimal/BigDecimal.csproj b/BigDecimal/BigDecimal.csproj
@@ -32,7 +32,7 @@
 
 	<PropertyGroup>
 		<MajorVersion Condition=" '$(MajorVersion)' == '' ">2025</MajorVersion>
-		<MinorVersion Condition=" '$(MinorVersion)' == '' ">1000</MinorVersion>
+		<MinorVersion Condition=" '$(MinorVersion)' == '' ">1001</MinorVersion>
 		<PatchVersion Condition=" '$(PatchVersion)' == '' ">2</PatchVersion>
 
 		<BuildTimestamp>$([System.DateTime]::Now.DayOfYear.ToString().PadLeft(3,'0'))</BuildTimestamp>

diff --git a/TestBigDecimal/TestBigDecimalOperations.cs b/TestBigDecimal/TestBigDecimalOperations.cs
@@ -409,6 +409,60 @@ public void TestMultiply2()
 			Assert.AreEqual(expected, actual.ToString());
 		}
 
+
+		[Test]
+		public void TestExponentiation1()
+		{
+			double exp = 0.052631578947368421d;
+			double phi = (1.0d + Math.Sqrt(5)) / 2.0d;
+
+			BigDecimal result1 = BigDecimal.Pow(9.0d, 0.5d);
+			BigDecimal result2 = BigDecimal.Pow(16.0d, 0.25d);
+			string expected1 = "3";
+			string expected2 = "2";
+
+			BigDecimal result3 = BigDecimal.Pow(phi, 13);
+			string expected3 = "521.001919378725";
+
+			BigDecimal result4 = BigDecimal.Pow(1162261467, exp);
+			BigDecimal result5 = BigDecimal.Pow(9349, exp);
+			string expected4 = "3";
+			string expected5 = "1.61803398777557";
+
+			BigDecimal result6 = BigDecimal.Pow(1.618034d, 16.000000256d);
+			BigDecimal result7 = BigDecimal.Pow(phi, 20.0000000128d);
+			string expected6 = "2207.00006429941";
+			string expected7 = "15127.0000270679";
+
+			BigDecimal result8 = BigDecimal.Pow(29192926025390625d, 0.07142857142857142d);
+			string expected8 = "14.999999999999998";
+
+			Assert.AreEqual(expected1, result1.ToString());
+			Assert.AreEqual(expected2, result2.ToString());
+			Assert.AreEqual(expected3, result3.ToString().Substring(0, 16));
+			Assert.AreEqual(expected4, result4.ToString());
+			Assert.AreEqual(expected5, result5.ToString().Substring(0, 16));
+			Assert.AreEqual(expected6, result6.ToString().Substring(0, 16));
+			Assert.AreEqual(expected7, result7.ToString().Substring(0, 16));
+			Assert.AreEqual(expected8, result8.ToString());
+		}
+
+		[Test]
+		public void TestExponentiation2()
+		{
+			BigDecimal result1 = BigDecimal.Pow(new BigDecimal(16), new BigInteger(16));
+			BigDecimal result2 = BigDecimal.Pow(new BigDecimal(101), new BigInteger(13));
+			string expected1 = "18446744073709551616";
+			string expected2 = "113809328043328941786781301";
+
+			BigDecimal result3 = BigDecimal.Pow(new BigDecimal(0.25), 2);
+			string expected3 = "0.0625";
+
+			Assert.AreEqual(expected1, result1.ToString());
+			Assert.AreEqual(expected2, result2.ToString());
+			Assert.AreEqual(expected3, result3.ToString());
+		}
+
 		[Test]
 		public void TestNegate()
 		{