/* RMS hook. * * Author: Manuel Pitz * 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 RMSHook : public MultiSignalHook { protected: std::vector> smpMemory; std::vector accumulator; unsigned windowSize; uint64_t smpMemoryPosition; public: RMSHook(Path *p, Node *n, int fl, int prio, bool en = true) : MultiSignalHook(p, n, fl, prio, en), smpMemory(), windowSize(0), 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 rms hook can only operate on signals of type float!"); } /* Initialize memory for each channel*/ smpMemory.clear(); for (unsigned i = 0; i < signalIndices.size(); i++) { accumulator.push_back(0.0); smpMemory.emplace_back(windowSize, 0.0); } state = State::PREPARED; } virtual void parse(json_t *json) { int ret; int windowSizeIn; json_error_t err; assert(state != State::STARTED); MultiSignalHook::parse(json); ret = json_unpack_ex(json, &err, 0, "{ s: i }", "window_size", &windowSizeIn); if (ret) throw ConfigError(json, err, "node-config-hook-rms"); if (windowSizeIn < 1) throw ConfigError(json, "node-config-hook-rms", "Window size must be greater 0 but is set to {}", windowSizeIn); windowSize = (unsigned)windowSizeIn; state = State::PARSED; } virtual Hook::Reason process(struct Sample *smp) { assert(state == State::STARTED); unsigned i = 0; for (auto index : signalIndices) { // Square the new value double newValue = pow(smp->data[index].f, 2); // Get the old value from the history double oldValue = smpMemory[i][smpMemoryPosition % windowSize]; // Append the new value to the history memory smpMemory[i][smpMemoryPosition % windowSize] = newValue; // Update the accumulator accumulator[index] += newValue; accumulator[index] -= oldValue; auto rms = pow(accumulator[index] / windowSize, 0.5); smp->data[index].f = rms; i++; } smpMemoryPosition++; return Reason::OK; } }; // Register hook static char n[] = "rms"; static char d[] = "This hook calculates the root-mean-square (RMS) on a window"; static HookPlugin p; } // namespace node } // namespace villas