huge commit

- worked on about everything
- grid walker using plugable modules
- wifi models
- new distributions
- worked on geometric data-structures
- added typesafe timestamps
- worked on grid-building
- added sensor-classes
- added sensor analysis (step-detection, turn-detection)
- offline data reader
- many test-cases

sensors/radio/WiFiProbabilityGrid.h

@@ -0,0 +1,92 @@
+#ifndef WIFIPROBABILITYGRID_H
+#define WIFIPROBABILITYGRID_H
+
+#include <fstream>
+
+#include "../../math/Distributions.h"
+#include "../../data/Timestamp.h"
+
+#include "WiFiProbability.h"
+
+
+/**
+ * probability is calculated by comparing pre-calculated wifi-signal-strengths
+ * attached to each grid-node with a given WiFiMeasurements data structure
+ */
+class WiFiObserverGrid : public WiFiProbability {
+
+private:
+
+	/** base-sigma to use for comparison */
+	float sigma = 8.0f;
+
+	/** additional sigma-per-second (measurement age) to*/
+	float sigmaPerSecond = 1.5;
+
+
+public:
+
+	/** ctor with uncertainty */
+	WiFiObserverGrid(const float sigma) : sigma(sigma) {
+		;
+	}
+
+	/**
+	 * get the given GridNode's probability.
+	 * compares the predicted signal-strengths stored on the given node
+	 * with the provided WiFi measurements
+	 */
+	template <typename Node> double getProbability(const Node& n, const Timestamp curTime, const WiFiMeasurements& obs) const {
+
+		double prob = 0;
+
+		// process each observed measurement
+		for (const WiFiMeasurement& measurement : obs.entries) {
+
+			// determine the age for this measurement
+			const Timestamp age = curTime - measurement.getTimestamp();
+
+			// sigma grows with measurement age
+			const float sigma = this->sigma + this->sigmaPerSecond * age.sec();
+
+			// the RSSI from the scan
+			const float measuredRSSI = measurement.getRSSI();
+
+			// the RSSI from the model (if available!)
+			const float modelRSSI = n.getRSSI(measurement.getAP().getMAC());
+
+			// no model RSSI available?
+			if (modelRSSI == 0) {continue;}
+
+			// compare both
+			const double p = Distribution::Normal<double>::getProbability(measuredRSSI, sigma, modelRSSI);
+
+			// adjust using log
+			prob += std::log(p);
+
+		}
+
+		//return std::pow(std::exp(prob), 0.1);
+		return std::exp(prob);
+
+	}
+
+	/** gnuplot debug dump */
+	template <typename Node> void dump(Grid<Node>& grid, const Timestamp curTime, const WiFiMeasurements& obs, const std::string& fileName) {
+
+		std::ofstream out(fileName);
+		out << "splot '-' with points palette\n";
+
+		for (const Node& n : grid) {
+			const float p = getProbability(n, curTime, obs);
+			out << n.x_cm << " " << n.y_cm << " " << n.z_cm << " " << p << "\n";
+		}
+		out << "e\n";
+
+		out.close();
+
+	}
+
+};
+
+#endif // WIFIPROBABILITYGRID_H