Improve WithinTolerance method (transferred from Unit Tests)

University Physics Tests/Helpers.cs

@@ -1,41 +1,15 @@
-using System;
-using UniversityPhysics.Maths;
+using UniversityPhysics.Maths;
 
 namespace UniversityPhysics_Tests
 {
     public static class Helpers
     {
-        #region Public Fields
-
-        /// <summary>
-        /// Percentage of allowed difference when accounting for floating point errors
-        /// </summary>
-        public const double tolerance = 0.5;
-
-        #endregion Public Fields
-
-        // percent
 
         #region Public Methods
 
-        public static bool WithinTolerance(double result, double expected)
+        public static bool WithinTolerance(double a, double b)
         {
-            //basic check. Necessary for case where result == expected == 0
-            if (result == expected)
-                return true;
-
-            //force both into positive values, so 'highest' (below) is not 0;
-            //necessary to prevent DivideByZero issue when dividing be 'highest'
-            result = Math.Abs(result);
-            expected = Math.Abs(expected);
-
-            double highest = Math.Max(result, expected);
-
-            double diff = Math.Abs(result - expected);
-
-            double percentOff = ((diff / highest) * 100);
-
-            return percentOff < tolerance;
+            return MathsHelpers.WithinTolerance(a, b);
         }
 
         public static bool WithinTolerance(Vector result, Vector expected)

University Physics/Maths/MathsHelpers.cs

@@ -9,9 +9,9 @@ public static class MathsHelpers
         #region Private Fields
 
         /// <summary>
-        /// For value comparison. Necessary for avoiding floating point accurary errors
+        /// Percentage of allowed difference when accounting for floating point errors
         /// </summary>
-        private const double tolerance = 0.0000001;
+        public const double Tolerance = 0.5;
 
         #endregion Private Fields
 
@@ -80,7 +80,24 @@ public static double DistanceTo(this Vector v1, Vector v2)
 
         public static bool WithinTolerance(double a, double b)
         {
-            return Math.Abs(a - b) <= tolerance;
+            //basic check. 
+            if (a == b)
+                return true;
+
+            // Convert both into positive values.
+            // This ensures the higher of the two values is always the denominator
+            // in division below, to prevents a DivideByZero exception.
+
+            a = Math.Abs(a);
+            b = Math.Abs(b);
+
+            double highest = Math.Max(a, b);
+
+            double diff = Math.Abs(a - b);
+
+            double percentOff = (diff / highest) * 100;
+
+            return percentOff < Tolerance;
         }
 
         public static double ToDegrees(double radians)