statistic helper classes

test-cases
modified grid importance for better trap-detection

math/stats/Average.h

@@ -0,0 +1,43 @@
+#ifndef AVERAGE_H
+#define AVERAGE_H
+
+#include "../../Assertions.h"
+
+namespace Stats {
+
+	template <typename Scalar> class Average {
+
+	private:
+
+		int cnt;
+		Scalar sum;
+
+	public:
+
+		/** ctor */
+		Average() : cnt(0), sum(0) {
+			;
+		}
+
+		/** contains a valid average? */
+		bool isValid() const {
+			return cnt > 0;
+		}
+
+		/** add a new value */
+		void add(const Scalar val) {
+			sum += val;
+			++cnt;
+		}
+
+		/** get the current value */
+		Scalar get() const {
+			Assert::isNot0(cnt, "add() values first!");
+			return sum / (Scalar)cnt;
+		}
+
+	};
+
+}
+
+#endif // AVERAGE_H