TrajectoryParametrization/src/CurvilinearTrajectoryParameters.cc

0001 #include "TrackingTools/TrajectoryParametrization/interface/CurvilinearTrajectoryParameters.h"
0002 #include <cmath>
0003
0004 CurvilinearTrajectoryParameters::CurvilinearTrajectoryParameters(const GlobalPoint& aX,
0005                                                                  const GlobalVector& aP,
0006                                                                  TrackCharge aCharge) {
0007   theQbp = aCharge / aP.mag();
0008
0009   double pT2 = aP.x() * aP.x() + aP.y() * aP.y();
0010   double pT = sqrt(pT2);
0011   thelambda = atan(aP.z() / pT);
0012   thephi = atan2(aP.y(), aP.x());
0013   thexT = (-aP.y() * aX.x() + aP.x() * aX.y()) / pT;
0014   theyT = (-aX.x() * aP.x() * aP.z() - aX.y() * aP.z() * aP.y() + aX.z() * (pT2)) / (aP.mag() * pT);
0015 }
0016
0017 bool CurvilinearTrajectoryParameters::updateP(double dP) {
0018   //FIXME. something is very likely to be missing here
0019   double p = 1. / std::abs(Qbp());
0020   if ((p += dP) <= 0.)
0021     return false;
0022   double newQbp = Qbp() > 0 ? 1. / p : -1. / p;
0023   theQbp = newQbp;
0024   return true;
0025 }