/* Moving average filter. * * Author: Steffen Vogel * SPDX-FileCopyrightText: 2014-2023 Institute for Automation of Complex Power Systems, RWTH Aachen University * SPDX-License-Identifier: Apache-2.0 */ #include #include namespace villas { namespace node { class MovingAverageHook : public MultiSignalHook { protected: std::vector> smpMemory; double accumulator; unsigned windowSize; uint64_t smpMemoryPosition; public: MovingAverageHook(Path *p, Node *n, int fl, int prio, bool en = true) : MultiSignalHook(p, n, fl, prio, en), smpMemory(), accumulator(0.0), windowSize(10), smpMemoryPosition(0) {} virtual void prepare() { MultiSignalHook::prepare(); // Add signals for (auto index : signalIndices) { auto origSig = signals->getByIndex(index); // Check that signal has float type if (origSig->type != SignalType::FLOAT) throw RuntimeError( "The ma hook can only operate on signals of type float!"); } // Initialize sample memory smpMemory.clear(); for (unsigned i = 0; i < signalIndices.size(); i++) smpMemory.emplace_back(windowSize, 0.0); state = State::PREPARED; } virtual void parse(json_t *json) { int ret; json_error_t err; assert(state != State::STARTED); MultiSignalHook::parse(json); ret = json_unpack_ex(json, &err, 0, "{ s?: i }", "window_size", &windowSize); if (ret) throw ConfigError(json, err, "node-config-hook-rms"); state = State::PARSED; } virtual Hook::Reason process(struct Sample *smp) { assert(state == State::STARTED); unsigned i = 0; for (auto index : signalIndices) { // The new value double newValue = smp->data[index].f; // Append the new value to the history memory smpMemory[i][smpMemoryPosition % windowSize] = newValue; // Get the old value from the history double oldValue = smpMemory[i][(smpMemoryPosition + 1) % windowSize]; // Update the accumulator accumulator += newValue; accumulator -= oldValue; smp->data[index].f = accumulator / windowSize; i++; } smpMemoryPosition++; return Reason::OK; } }; // Register hook static char n[] = "ma"; static char d[] = "A simple moving average filter over a fixed number of past samples"; static HookPlugin p; } // namespace node } // namespace villas