/data/refman/pasoursint/CMSSW_4_4_5_patch3/src/TrackingTools/AnalyticalJacobians/src/JacobianCurvilinearToLocal.cc

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#include "TrackingTools/AnalyticalJacobians/interface/JacobianCurvilinearToLocal.h"
#include "DataFormats/GeometrySurface/interface/Surface.h"
#include "TrackingTools/TrajectoryParametrization/interface/LocalTrajectoryParameters.h"
#include "MagneticField/Engine/interface/MagneticField.h"

JacobianCurvilinearToLocal::
JacobianCurvilinearToLocal(const Surface& surface, 
                           const LocalTrajectoryParameters& localParameters,
                           const MagneticField& magField) : theJacobian() {
 
  // Origin: TRSCSD
  GlobalPoint  x = surface.toGlobal(localParameters.position());
  GlobalVector h  = magField.inInverseGeV(x);
  GlobalVector  hdir =  h.unit();

  LocalVector tnl = localParameters.momentum().unit();
  GlobalVector tn = surface.toGlobal(tnl);

  // GlobalVector dj = surface.toGlobal(LocalVector(1., 0., 0.));
  // GlobalVector dk = surface.toGlobal(LocalVector(0., 1., 0.));
  //  GlobalVector di = surface.toGlobal(LocalVector(0., 0., 1.));
  Surface::RotationType const & rot = surface.rotation();
  GlobalVector dj(rot.x());
  GlobalVector dk(rot.y());
  GlobalVector di(rot.z());

  // rotate coordinates because of wrong coordinate system in orca
  // LocalVector tvw(tnl.z(), tnl.x(), tnl.y());
  double cosl = tn.perp(); if (cosl < 1.e-30) cosl = 1.e-30;
  double cosl1 = 1./cosl;
  GlobalVector un(-tn.y()*cosl1, tn.x()*cosl1, 0.);
  GlobalVector vn(-tn.z()*un.y(), tn.z()*un.x(), cosl);

  double uj = un.dot(dj);
  double uk = un.dot(dk);
  double vj = vn.dot(dj);
  double vk = vn.dot(dk);

  //  double t1r = 1./tvw.x();
  double t1r = 1./tnl.z();
  double t2r = t1r*t1r;
  double t3r = t1r*t2r;

  theJacobian(0,0) = 1.;
  theJacobian(1,1) = -uk*t2r;
  theJacobian(1,2) = vk*(cosl*t2r);
  theJacobian(2,1) = uj*t2r;
  theJacobian(2,2) = -vj*(cosl*t2r);
  theJacobian(3,3) = vk*t1r;
  theJacobian(3,4) = -uk*t1r;
  theJacobian(4,3) = -vj*t1r;
  theJacobian(4,4) = uj*t1r;

  double q = -h.mag() * localParameters.signedInverseMomentum();

  double sinz =-un.dot(hdir);
  double cosz = vn.dot(hdir);
  double ui = un.dot(di)*(q*t3r);
  double vi = vn.dot(di)*(q*t3r);
  theJacobian(1,3) =-ui*(vk*cosz-uk*sinz);
  theJacobian(1,4) =-vi*(vk*cosz-uk*sinz);
  theJacobian(2,3) = ui*(vj*cosz-uj*sinz);
  theJacobian(2,4) = vi*(vj*cosz-uj*sinz);
  // end of TRSCSD
  //dbg::dbg_trace(1,"Cu2L", localParameters.vector(),di,dj,dk,theJacobian);
}