ADD: new track message, Entity class and Position class

libs/geographiclib/examples/example-AuxLatitude.cpp

@@ -0,0 +1,37 @@
+// Example of using the GeographicLib::AuxLatitude class.  See the paper
+//
+// - C. F. F. Karney,
+//   On auxiliary latitudes,
+//   Technical Report, SRI International, December 2022.
+//   https://arxiv.org/abs/2212.05818
+
+#include <iostream>
+#include <iomanip>
+#include <exception>
+#include "AuxLatitude.hpp"
+
+using namespace std;
+
+int main() {
+  try {
+    typedef GeographicLib::AuxLatitude<double> latitude;
+    typedef latitude::angle angle;
+    double a = 2, b = 1;        // Equatorial radius and polar semi-axis
+    latitude aux(a, b);
+    bool series = false;        // Don't use series method
+    int auxin = latitude::GEOGRAPHIC;
+    cout << setprecision(9) << fixed;
+    for (int l = 0; l <= 90; ++l) {
+      angle phi(angle::degrees(l));
+      for (int auxout = 0; auxout < latitude::AUXNUMBER; ++auxout) {
+        angle eta = aux.Convert(auxin, auxout, phi, series);
+        cout << (auxout ? " " : "") << eta.degrees();
+      }
+      cout << "\n";
+    }
+  }
+  catch (const exception& e) {
+    cerr << "Caught exception: " << e.what() << "\n";
+    return 1;
+  }
+}