worked on signal-strength-estimation

add this information to grid nodes
evaluate this information
new test-cases

sensors/radio/WiFiGridEstimator.h

@@ -0,0 +1,84 @@
+#ifndef WIFIGRIDESTIMATOR_H
+#define WIFIGRIDESTIMATOR_H
+
+#include "../../grid/Grid.h"
+#include "model/WiFiModel.h"
+#include "WiFiGridNode.h"
+#include "../../Assertions.h"
+
+#include <fstream>
+
+/**
+ * estimates the signal-strength for all APs at a given GridNode
+ * and stores this precalculated value onto the node
+ */
+class WiFiGridEstimator {
+
+public:
+
+	/**
+	 * perform a signal-strength estimation for all of the given access points
+	 * using the provided signal-strength prediction model.
+	 * store the estimated strength onto each node.
+	 * as nodes only provide a limited number of rssi-entries,
+	 * store only the strongest ones.
+	 */
+	template <typename Node> static void estimate(Grid<Node>& grid, WiFiModel& mdl, const std::vector<LocatedAccessPoint> aps) {
+
+		// sanity checks
+		Assert::isTrue(Node::getMapAPs().empty(), "there are already some processed APs available!");
+
+		// attach the access-points to the shared node-vector
+		for (const LocatedAccessPoint& ap : aps) {
+			Node::getMapAPs().push_back(ap);
+		}
+
+		// process each node
+		for (Node& n : grid) {
+
+			// keep the strongest APs to attach to this node
+			std::vector<WiFiGridNodeAP> nodeAPs;
+
+			// process each AP
+			for (int apIdx = 0; apIdx < (int) aps.size(); ++apIdx) {
+
+				// estimate the signal-strength
+				const float rssi = mdl.getRSSI(aps[apIdx], n.inMeter());
+
+				// keep it
+				nodeAPs.push_back(WiFiGridNodeAP(apIdx, rssi));
+
+			}
+
+			// sort all APs by signal strength
+			auto comp = [] (const WiFiGridNodeAP& ap1, const WiFiGridNodeAP& ap2) {return ap1.getRSSI() > ap2.getRSSI();};
+			std::sort(nodeAPs.begin(), nodeAPs.end(), comp);
+
+			// attach the strongest X to the node
+			const int cnt = std::min( n.getMaxAPs(), (int) nodeAPs.size() );
+			for (int i = 0; i < cnt; ++i) {
+				n.strongestAPs[i] = nodeAPs[i];
+			}
+
+		}
+
+	}
+
+
+	/** gnuplot visualization dump for the given AP */
+	template <typename Node> static void dump(Grid<Node>& grid, const std::string& mac, const std::string& filename) {
+
+		std::ofstream out(filename);
+		out << "splot '-' with points palette \n";
+
+		for (Node& n : grid) {
+			out << n.x_cm << " " << n.y_cm << " " << n.z_cm << " " << n.getRSSI(mac) << "\n";
+		}
+		out << "e\n";
+		out.close();
+
+	}
+
+};
+
+#endif // WIFIGRIDESTIMATOR_H