#include <JacobianCurvilinearToCartesian.h>

Public Member Functions
const AlgebraicMatrix65 &	jacobian () const

	JacobianCurvilinearToCartesian (const GlobalTrajectoryParameters &globalParameters)

Private Attributes
AlgebraicMatrix65	theJacobian

Detailed Description

Class which calculates the Jacobian matrix of the transformation from the curvilinear to the Cartesian frame. The Jacobian is calculated during construction and thereafter cached, enabling reuse of the same Jacobian without calculating it again.

Definition at line 14 of file JacobianCurvilinearToCartesian.h.

Constructor & Destructor Documentation

JacobianCurvilinearToCartesian::JacobianCurvilinearToCartesian ( const GlobalTrajectoryParameters & globalParameters )

Constructor from global trajectory parameters. NB!! No default constructor exists!

Definition at line 5 of file JacobianCurvilinearToCartesian.cc.

References GlobalTrajectoryParameters::charge(), funct::cos(), Vector3DBase< T, FrameTag >::cross(), M_PI, PV3DBase< T, PVType, FrameType >::mag(), GlobalTrajectoryParameters::momentum(), AlCaHLTBitMon_ParallelJobs::p, p2, PV3DBase< T, PVType, FrameType >::perp(), phi, PV3DBase< T, PVType, FrameType >::phi(), lumiQueryAPI::q, dttmaxenums::R, funct::sin(), theJacobian, PV3DBase< T, PVType, FrameType >::theta(), Vector3DBase< T, FrameTag >::unit(), PV3DBase< T, PVType, FrameType >::x(), PV3DBase< T, PVType, FrameType >::y(), and PV3DBase< T, PVType, FrameType >::z().

                                                                                    : theJacobian() {
   GlobalVector xt = globalParameters.momentum();
   //GlobalVector yt(xt.y(), -xt.x(), 0.); \\wrong direction of the axis
   //GlobalVector zt(xt.x()*xt.z(), xt.y()*xt.z(), -xt.perp2()); \\and then also on this one
   GlobalVector yt(-xt.y(), xt.x(), 0.); 
   GlobalVector zt = xt.cross(yt);
 
   GlobalVector pvec = globalParameters.momentum();
   double pt = pvec.perp();
   TrackCharge q = globalParameters.charge();
   // for neutrals: qbp is 1/p instead of q/p - 
   //   equivalent to charge 1
   if ( q==0 )  q = 1;
 
   xt = xt.unit(); 
   if(fabs(pt) > 0){
     yt = yt.unit(); 
     zt = zt.unit();
   }
   
   AlgebraicMatrix66 R;
   R(0,0) = xt.x(); R(0,1) = yt.x(); R(0,2) = zt.x();
   R(1,0) = xt.y(); R(1,1) = yt.y(); R(1,2) = zt.y();
   R(2,0) = xt.z(); R(2,1) = yt.z(); R(2,2) = zt.z();
   R(3,3) = 1.;
   R(4,4) = 1.;
   R(5,5) = 1.;
 
   double p = pvec.mag(), p2 = p*p;
   double lambda = 0.5 * M_PI - pvec.theta();
   double phi = pvec.phi();
   double sinlambda = sin(lambda), coslambda = cos(lambda);
   double sinphi = sin(phi), cosphi = cos(phi);
 
   theJacobian(1,3) = 1.;
   theJacobian(2,4) = 1.;
   theJacobian(3,0) = -q * p2 * coslambda * cosphi;
   theJacobian(3,1) = -p * sinlambda * cosphi;
   theJacobian(3,2) = -p * coslambda * sinphi;
   theJacobian(4,0) = -q * p2 * coslambda * sinphi;
   theJacobian(4,1) = -p * sinlambda * sinphi;
   theJacobian(4,2) = p * coslambda * cosphi;
   theJacobian(5,0) = -q * p2 * sinlambda;
   theJacobian(5,1) = p * coslambda;
   theJacobian(5,2) = 0.;
 
   //ErrorPropagation: 
   //    C(Cart) = R(6*6) * J(6*5) * C(Curvi) * J(5*6)_T * R(6*6)_T
   theJacobian = R*theJacobian;
   //dbg::dbg_trace(1,"Cu2Ca", globalParameters.vector(),theJacobian);
 }