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//--------------------------------------------------------------------------------------------------
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// $Id: TrackParameters.h,v 1.3 2008/09/10 03:28:38 loizides Exp $
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//
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// Description: class TrackParameters
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//
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// Class to manage track parameters of different conventions and convert one into the other. This is
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// not really done very well and could be done more efficient but this is what it is for the moment.
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//
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// Original Author: Christoph Paus
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// Created: Thu Aug 21 02:29:00 CEST 2008
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//
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// -------------------------------------------------------------------------------------------------
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// CMS parameter ordering for the vector/matrix, which is assumed here:
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//
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// qoverp, lambda, phi0, dxy, dsz; (lambda = pi/2 - theta)
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// mapping to CDF is therefore { 1*, 0*, 4, 3, 2* }, where * indicates that a transformation is
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// needed
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//
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// Note that the radius of curvature (in cm) is then:
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//
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// Rc = cos(theta) / [ 0.0029979.... * (q/p) * B ],
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//
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// where B is the magnetic field in Tesla and tht is the angle between the field and the
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// direction. With p * cos(theta) = pT it follows:
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//
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// Rc = pT / [ 0.0029979.... * q * B ],
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// fullCurvature = 1 / Rc = 0.0029979 * q * B / pT = - 0.0029979 * B / pT.
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//
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// see the conventions for the MultiVertexFitter in its own header file.
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//
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// Author: C.Paus
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//--------------------------------------------------------------------------------------------------
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#ifndef MITEDM_VERTEXFITINTERFACE_TRACKPARAMETERS_H
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#define MITEDM_VERTEXFITINTERFACE_TRACKPARAMETERS_H
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#include <TMatrixDSym.h>
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#include <TVectorD.h>
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#include "DataFormats/TrackReco/interface/Track.h"
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namespace mitedm
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{
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enum TrackConvention { // Define existing track parameter conventions
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iCms,
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iMvf
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};
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// Declare the track parameter class
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class TrackParameters
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{
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public:
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TrackParameters() {}
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TrackParameters(const reco::Track *trk, TrackConvention tcv = iCms, double bField = 3.8);
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TrackParameters(const TrackParameters &trk);
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~TrackParameters() {};
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// Access the specific contents
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const TVectorD *pars() const { return &pars_; };
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double pars(int i) const { return pars_[i]; };
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const TMatrixDSym *cMat() const { return &cMat_; };
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double cMat(int i, int j) const { return cMat_(i,j); };
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// Access the different parametrizations independently of the local storage
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TrackParameters cmsTrack() const;
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TrackParameters mvfTrack() const;
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void setPars(int i, double v) { pars_(i) = v; }
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void setCMat(int i, int j, double v) { cMat_(i,j) = v; }
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void addCMat(int i, int j, double v) { cMat_(i,j) += v; }
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// Utilities
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void print() const;
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private:
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TrackConvention iConvention_; //track parameter convention (def. CMS)
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double bField_; //magnetic field in Tesla
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double fCurv_; //combined curvature constant
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TVectorD pars_; //track paramters (helix)
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TMatrixDSym cMat_; //corresponding covariance matrix (sig_i * sig_j)
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};
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}
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#endif
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