dsp: started working on a moving average window

common/include/villas/dsp/moving_average.hpp

@@ -0,0 +1,63 @@
+/** A moving average filter.
+ *
+ * @file
+ * @author Steffen Vogel <stvogel@eonerc.rwth-aachen.de>
+ * @copyright 2014-2019, Institute for Automation of Complex Power Systems, EONERC
+ * @license GNU General Public License (version 3)
+ *
+ * VILLAScommon
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ *********************************************************************************/
+
+#pragma once
+
+#include <villas/window.hpp>
+
+namespace villas {
+namespace dsp {
+
+template<typename T>
+class MovingAverage {
+
+public:
+	typedef typename Window<T>::size_type size_type;
+
+protected:
+	Window<T> window;
+
+	size_type length;
+
+	T state;
+
+public:
+	MovingAverage(size_type len, T i) :
+		window(len, i),
+		length(len),
+		state(i)
+	{ }
+
+	T update(T in)
+	{
+		T out = window.update(in);
+
+		state += in;
+		state -= out;
+
+		return state / len;
+	}
+};
+
+} // namespace dsp
+} // namespace villas