PathToPlane2Order Class Reference

#include <PathToPlane2Order.h>

Public Types
typedef GloballyPositioned< Scalar >	Frame
typedef Plane::Scalar	Scalar
typedef Basic3DVector< Scalar >	Vector3D

Public Member Functions
std::pair< bool, double >	operator() (const Plane &plane, const Vector3D &position, const Vector3D &momentum, double charge, const PropagationDirection propDir=alongMomentum)
std::pair< bool, double >	operator() (const Plane &plane, const GlobalPoint &position, const GlobalVector &momentum, double charge, const PropagationDirection propDir=alongMomentum)
	PathToPlane2Order (const RKLocalFieldProvider &fld, const Frame *fieldFrame)

Private Attributes
const RKLocalFieldProvider &	theField
const Frame *	theFieldFrame

Detailed Description

Definition at line 21 of file PathToPlane2Order.h.

Member Typedef Documentation

Frame

typedef GloballyPositioned<Scalar> PathToPlane2Order::Frame

Definition at line 25 of file PathToPlane2Order.h.

Scalar

typedef Plane::Scalar PathToPlane2Order::Scalar

Definition at line 23 of file PathToPlane2Order.h.

Vector3D

typedef Basic3DVector<Scalar> PathToPlane2Order::Vector3D

Definition at line 24 of file PathToPlane2Order.h.

Constructor & Destructor Documentation

PathToPlane2Order()

PathToPlane2Order::PathToPlane2Order ( const RKLocalFieldProvider &  fld, const Frame *  fieldFrame  )

inline

Definition at line 27 of file PathToPlane2Order.h.

      : theField(fld), theFieldFrame(fieldFrame) {}

Member Function Documentation

operator()() [1/2]

std::pair< bool, double > PathToPlane2Order::operator()	(	const Plane &	plane,
		const Vector3D &	position,
		const Vector3D &	momentum,
		double	charge,
		const PropagationDirection	propDir = alongMomentum
	)

the position and momentum are local in the FieldFrame; the plane is in the global frame

Definition at line 8 of file PathToPlane2Order.cc.

References B, PV3DBase< T, PVType, FrameType >::basicVector(), ALCARECOTkAlJpsiMuMu_cff::charge, Vector3DBase< T, FrameTag >::cross(), PixelRecoUtilities::curvature(), amptDefault_cfi::frame, RKLocalFieldProvider::inTesla(), dqmdumpme::k, PV3DBase< T, PVType, FrameType >::mag(), PV3DBase< T, PVType, FrameType >::perp(), theField, theFieldFrame, GloballyPositioned< T >::toGlobal(), FrameChanger::transformPlane(), and Vector3DBase< T, FrameTag >::unit().

                                                                                          {
  // access to the field in field frame local coordinates
  RKLocalFieldProvider::Vector B = theField.inTesla(pos.x(), pos.y(), pos.z());

  // Frame::GlobalVector localZ = Frame::GlobalVector( B.unit()); // local Z along field
  // transform field axis to global frame
  Frame::GlobalVector localZ = theFieldFrame->toGlobal(Frame::LocalVector(B.unit()));  // local Z along field

  Frame::GlobalVector localY = localZ.cross(Frame::GlobalVector(1, 0, 0));
  if (localY.mag() < 0.1) {
    localY = localZ.cross(Frame::GlobalVector(0, 1, 0)).unit();
  } else {
    localY = localY.unit();
  }
  Frame::GlobalVector localX = localY.cross(localZ);

  Frame::PositionType fpos(theFieldFrame->toGlobal(Frame::LocalPoint(pos)));
  Frame::RotationType frot(localX, localY, localZ);
  // frame in which the field is along Z
  Frame frame(fpos, frot);

  //    cout << "PathToPlane2Order frame " << frame.position() << endl << frame.rotation() << endl;

  // transform the position and direction to that frame
  Frame::LocalPoint localPos = frame.toLocal(fpos);  // same as LocalPoint(0,0,0)

  //transform momentum from field frame to new frame via global frame
  Frame::GlobalVector gmom(theFieldFrame->toGlobal(Frame::LocalVector(momentum)));
  Frame::LocalVector localMom = frame.toLocal(gmom);

  // transform the plane to the same frame
  Plane localPlane = FrameChanger::transformPlane(plane, frame);
  /*
     cout << "PathToPlane2Order input plane       " << plane.position() << endl 
     << plane.rotation() << endl;
     cout << "PathToPlane2Order transformed plane " << localPlane->position() << endl 
     << localPlane->rotation() << endl;
*/
  double k = 2.99792458e-3;
  double transverseMomentum = localMom.perp();  // transverse to the field
  if (!(transverseMomentum != 0)) {             // if (!(x!=0)) will trap both 0 and NaN
    //LogDebug("PathToPlane2Order_ZeroMomentum") << "Momentum transverse to the field is zero or Nan (" << transverseMomentum << ")\n";
    return std::pair<bool, double>(false, 0);
  }
  double curvature = -k * charge * B.mag() / transverseMomentum;
  /*
     cout << "PathToPlane2Order curvature " << curvature << endl;
     cout << "transverseMomentum " << transverseMomentum << endl;
     cout << "B.mag() " << B.mag() << endl;
     cout << "localZ " << localZ << endl;
     cout << "pos      " << pos << endl;
     cout << "momentum " << momentum << endl;
     cout << "localPos " << localPos << endl;
     cout << "localMom " << localMom << endl;
*/
  /*
    cout << "PathToPlane2Order: local pos " << localPos << " mom " << localMom 
     << " curvature " << curvature << endl;
    cout << "PathToPlane2Order: local plane pos " << localPlane->position() 
     << " normal " << localPlane->normalVector() << endl;
*/
  HelixArbitraryPlaneCrossing crossing(localPos.basicVector(), localMom.basicVector(), curvature, propDir);
  std::pair<bool, double> res = crossing.pathLength(localPlane);

  return res;
}

operator()() [2/2]

std::pair<bool, double> PathToPlane2Order::operator() ( const Plane &  plane, const GlobalPoint &  position, const GlobalVector &  momentum, double  charge, const PropagationDirection  propDir = alongMomentum  )

inline

Definition at line 38 of file PathToPlane2Order.h.

References PV3DBase< T, PVType, FrameType >::basicVector(), ALCARECOTkAlJpsiMuMu_cff::charge, position, and GloballyPositioned< T >::toLocal().

                                                                                         {
    return operator()(plane,
                      theFieldFrame->toLocal(position).basicVector(),
                      theFieldFrame->toLocal(momentum).basicVector(),
                      charge,
                      propDir);
  }

Member Data Documentation

theField

const RKLocalFieldProvider& PathToPlane2Order::theField

private

Definition at line 51 of file PathToPlane2Order.h.

Referenced by operator()().

theFieldFrame

const Frame* PathToPlane2Order::theFieldFrame

private

Definition at line 52 of file PathToPlane2Order.h.

Referenced by operator()().