Update tests projects so they can be run.

Decimal2D.Tests/Decimal2D.Tests.csproj

@@ -1,7 +1,7 @@
 <Project Sdk="Microsoft.NET.Sdk">
 
   <PropertyGroup>
-    <TargetFramework>netcoreapp2.2</TargetFramework>
+    <TargetFramework>netcoreapp3.1</TargetFramework>
   </PropertyGroup>
 
   <ItemGroup>

Decimal2D/Circle2D.cs

@@ -592,8 +592,8 @@ public LineSeg2D TangentAt(decimal degrees, decimal length, bool clockwise)
             decimal rad = DecimalEx.ToRad(degrees + r.AngleA);
             LineSeg2D ret = default(LineSeg2D);
 
-            Debug.Assert(r.AngleA == RightTriangle.GetAngleFromSides(length, _radius));
-            Debug.Assert(r.Hypotenuse == RightTriangle.GetHypFromSides(length, _radius));
+            //Debug.Assert(r.AngleA == RightTriangle.GetAngleFromSides(length, _radius));
+            //Debug.Assert(r.Hypotenuse == RightTriangle.GetHypFromSides(length, _radius));
 
             ret.Pt1 = PointAt(degrees);
             if (!clockwise)

DecimalEx.Tests/DecimalEx.Tests.csproj

@@ -1,7 +1,7 @@
 <Project Sdk="Microsoft.NET.Sdk">
 
   <PropertyGroup>
-    <TargetFramework>netcoreapp2.2</TargetFramework>
+    <TargetFramework>netcoreapp3.1</TargetFramework>
   </PropertyGroup>
 
   <ItemGroup>

DecimalEx.Tests/DecimalExTests/PowTests.cs

@@ -12,19 +12,26 @@ public class PowTests
 
         public static decimal[][] TestCases =
         {
-                new[] {1m, 0m, 1m, 0m},
-                new[] {2m, 8m, 256m, 0m},
-                new[] {3m, 5m, 243m, 0m},
-                new[] {5m, 40m, 9094947017729282379150390625m, 0m},
-                new[] {99m, 1m, 99m, 0m},
+            new[] {1m, 0m, 1m, 0m},
+            new[] {2m, 8m, 256m, 0m},
+            new[] {3m, 5m, 243m, 0m},
+            new[] {5m, 40m, 9094947017729282379150390625m, 0m},
+            new[] {99m, 1m, 99m, 0m},
 
-                // Fractional powers are going to be off a bit
-                new[] {5m, .5m, 2.2360679774997896964091736687m, FractionalTolerance},
-                new[] {5m, 2.5m, 55.901699437494742410229341718m, FractionalTolerance},
-                new[] {5m, 10.5m, 21836601.342771383753995836609m, FractionalTolerance},
-                new[] {5m, 15.5m, 68239379196.160574231236989402m, FractionalTolerance},
-                new[] {5m, 20.5m, 213248059988001.79447261559188m, FractionalTolerance},
-                new[] {5m, 40.5m, 20336919783401660392056998432m, FractionalTolerance},
+            // Fractional powers are going to be off a bit
+            new[] {5m, .5m, 2.2360679774997896964091736687m, FractionalTolerance},
+            new[] {5m, 2.5m, 55.901699437494742410229341718m, FractionalTolerance},
+            new[] {5m, 10.5m, 21836601.342771383753995836609m, FractionalTolerance},
+            new[] {5m, 15.5m, 68239379196.160574231236989402m, FractionalTolerance},
+            new[] {5m, 20.5m, 213248059988001.79447261559188m, FractionalTolerance},
+            new[] {5m, 40.5m, 20336919783401660392056998432m, FractionalTolerance},
+        };
+
+        public static decimal[][] SqrTestCases =
+        {
+            new[] {1m, 1m},
+            new[] {8m, 64m},
+            new[] {3m, 9m},
         };
 
         [TestCaseSource("TestCases")]
@@ -40,6 +47,12 @@ public void NegativeExponentOfZero()
         {
             Assert.Throws<OverflowException>(() => DecimalEx.Pow(0, -1));
         }
-    }
 
+        [TestCaseSource("SqrTestCases")]
+        public void SqrSameAsPower2(decimal x, decimal expected)
+        {
+            Assert.That(DecimalEx.Pow(x, 2), Is.EqualTo(DecimalEx.Sqr(x)));
+            Assert.That(DecimalEx.Pow(x, 2), Is.EqualTo(expected));
+        }
+    }
 }

DecimalEx/DecimalEx.cs

@@ -1,5 +1,4 @@
 using System;
-using System.Diagnostics;
 using System.Linq;
 
 namespace DecimalMath
@@ -51,6 +50,15 @@ public static decimal Sqrt(decimal s)
             return nextX;
         }
 
+        /// <summary>
+        /// Returns a specified number raised to the power of 2 - squared.
+        /// </summary>
+        /// <param name="x">A number to be squared.</param>
+        public static decimal Sqr(decimal x)
+        {
+            return Pow(x, 2m);
+        }
+
         /// <summary>
         /// Returns a specified number raised to the specified power.
         /// </summary>
@@ -111,7 +119,7 @@ public static decimal Pow(decimal x, decimal y)
         /// </remarks>
         private static decimal ExpBySquaring(decimal x, decimal y)
         {
-            Debug.Assert(y >= 0 && decimal.Truncate(y) == y, "Only non-negative, integer powers supported.");
+            //Debug.Assert(y >= 0 && decimal.Truncate(y) == y, "Only non-negative, integer powers supported.");
             if (y < 0) throw new ArgumentOutOfRangeException("y", "Negative exponents not supported!");
             if (decimal.Truncate(y) != y) throw new ArgumentException("Exponent must be an integer!", "y");
 

DecimalEx/DecimalExTrig.cs

@@ -1,5 +1,4 @@
 using System;
-using System.Diagnostics;
 
 namespace DecimalMath
 {
@@ -118,8 +117,8 @@ public static decimal Sin(decimal x)
                     nextAdd *= -1 * xSquared / (doubleIteration * doubleIteration + doubleIteration);
                 }
 
-                Debug.WriteLine("{0:000}:{1,33:+0.0000000000000000000000000000;-0.0000000000000000000000000000} ->{2,33:+0.0000000000000000000000000000;-0.0000000000000000000000000000}",
-                    doubleIteration / 2, nextAdd, result + nextAdd);
+                //Debug.WriteLine("{0:000}:{1,33:+0.0000000000000000000000000000;-0.0000000000000000000000000000} ->{2,33:+0.0000000000000000000000000000;-0.0000000000000000000000000000}",
+                //    doubleIteration / 2, nextAdd, result + nextAdd);
                 if (nextAdd == 0) break;
 
                 result += nextAdd;