CMath::epsilonEqual fuzzy comparison function for doubles

refs #81

src/blackmisc/mathematics.cpp

@@ -62,6 +62,15 @@ namespace BlackMisc
             return rv;
         }
 
+        /*
+         * Equal, considering equal
+         */
+        bool CMath::epsilonEqual(double v1, double v2, double epsilon)
+        {
+            if (v1 == v2) return true;
+            return qAbs(v1-v2) <= epsilon;
+        }
+
         /*
          * To radians
          */

src/blackmisc/mathematics.h

@@ -71,6 +71,15 @@ namespace BlackMisc
              */
             static double roundEpsilon(double value, double epsilon);
 
+            /*!
+             * \brief Epsilon safe equal
+             * \param v1
+             * \param v2
+             * \param epsilon
+             * \return
+             */
+            static bool epsilonEqual(double v1, double v2, double epsilon = 1E-06);
+
             /*!
              * \brief Nearest integer not greater in magnitude than value, correcting for epsilon
              * \param value