code: def _determine_nTrackIterations(self,nTrackIterations):
          
          if not nTrackIterations is None:
              self.nTrackIterations= nTrackIterations
              return None
          if numpy.fabs(self.misalignment(quantity=False)) < 1./180.*numpy.pi:
              self.nTrackIterations= 0
          elif numpy.fabs(self.misalignment(quantity=False)) >= 1./180.*numpy.pi \
                  and numpy.fabs(self.misalignment(quantity=False)) < 3./180.*numpy.pi:
              self.nTrackIterations= 1
          elif numpy.fabs(self.misalignment(quantity=False)) >= 3./180.*numpy.pi:
              self.nTrackIterations= 2
          return None
docs: Determine a good value for nTrackIterations based on the misalignment between stream and orbit; just based on some rough experience for now