[Exogam] Added sanity check for failed NR convergence and fixed returned var in this case

NPLib/Detectors/Exogam/TExogamGeo.cxx

@@ -186,6 +186,7 @@ Vector3D TExogamGeo::newton_raphson(double initial_guess,
     Vector3D& TargetPos, double tolerance = 1e-6, int max_iterations = 100) {
     double alpha = initial_guess;
     Vector3D unit(0.,1.,0.);
+    Vector3D fail ;
     setclover(&unit);
     // std::cout << "new NewtonRaphson" << std::endl;
     for (int i = 0; i < max_iterations; ++i) {
@@ -204,15 +205,19 @@ Vector3D TExogamGeo::newton_raphson(double initial_guess,
 
         // Si la différence est inférieure à la tolérance, on considère la solution trouvée
         if (std::fabs(alpha_new - alpha) < tolerance) {
-
             return SegmentPos - TargetPos;
         }
         // std::cout << alpha << " " << alpha_new << std::endl;
         alpha = alpha_new;
+        fail = SegmentPos-TargetPos ;
     }
 
-    std::cerr << "Newton-Raphson n'a pas convergé après " << max_iterations << " itérations.\n";
-    Vector3D fail;
+    // If failed convergence is wrong by more than 100% of initial guess just return initial guess
+    if ((std::fabs(alpha - initial_guess) > (initial_guess *2)) ){
+      Vector3D outerpos = getouterpos(initial_guess,InteractionDepth);
+      Vector3D SegmentPos(outerpos.X(), getdistance() + std::cos(initial_guess) * InteractionDepth, outerpos.Z());
+      fail = SegmentPos - TargetPos;
+    }
     return fail;  // Retourne la dernière valeur trouvée si la convergence n'est pas atteinte
 }
 

NPLib/Detectors/Exogam/TExogamGeo.h

@@ -212,4 +212,4 @@ class TExogamCartesian: public TExogamGeo{
         double getdistance() override; 
         double tolerance = 1; // tolerance is in mm
 };
-#endif 
\ No newline at end of file
+#endif