.. _program_listing_file_conversions_anomaly_conversions.cc:

Program Listing for File anomaly_conversions.cc
===============================================

|exhale_lsh| :ref:`Return to documentation for file <file_conversions_anomaly_conversions.cc>` (``conversions/anomaly_conversions.cc``)

.. |exhale_lsh| unicode:: U+021B0 .. UPWARDS ARROW WITH TIP LEFTWARDS

.. code-block:: cpp

   #include "lupnt/conversions/anomaly_conversions.h"
   
   #include "lupnt/numerics/math_utils.h"
   
   namespace lupnt {
     Real GetOrbitalPeriod(Real a, Real GM) { return 2 * PI * sqrt(pow(a, 3) / GM); }
     VEC_IMP_REAL_REAL(GetOrbitalPeriod);
   
     Real EccToTrueAnomaly(Real E, Real e) { return atan2(sqrt(1 - pow(e, 2)) * sin(E), cos(E) - e); }
   
     Real EccToMeanAnomaly(Real E, Real e) { return WrapToPi(E - e * sin(E)); }
   
     Real MeanToEccAnomaly(Real M, Real e) {
       Real MM = WrapToPi(M);
   
       // Initial estimate of E
       Real E = MM;
       Real Eest = E - (E - e * sin(E) - MM) / (1.0 - e * cos(E));
   
       int max_itr = 100;
       int itr = 0;
       while ((abs(Eest - E) >= EPS) && (itr <= max_itr)) {
         E = Eest;
         Eest = E - (E - e * sin(E) - M) / (1.0 - e * cos(E));
         itr++;
       }
       E = Eest;
   
       return WrapToPi(E);
     }
   
     Real MeanToTrueAnomaly(Real M, Real e) {
       Real E = MeanToEccAnomaly(M, e);
       Real nu = EccToTrueAnomaly(E, e);
       return WrapToPi(nu);
     }
   
     Real TrueToEccAnomaly(Real nu, Real e) {
       Real E = 2 * atan(sqrt((1 - e) / (1 + e)) * tan(nu / 2));
       return E;
     }
   
     Real TrueToMeanAnomaly(Real nu, Real e) {
       Real E = TrueToEccAnomaly(nu, e);
       Real M = EccToMeanAnomaly(E, e);
       return M;
     }
   
     VEC_IMP_REAL_REAL(EccToTrueAnomaly);
     VEC_IMP_REAL_REAL(EccToMeanAnomaly);
     VEC_IMP_REAL_REAL(MeanToEccAnomaly);
     VEC_IMP_REAL_REAL(TrueToEccAnomaly);
     VEC_IMP_REAL_REAL(MeanToTrueAnomaly);
     VEC_IMP_REAL_REAL(TrueToMeanAnomaly);
   }  // namespace lupnt