source: git/external/TrackCovariance/TrkUtil.h@ 4e8e72b

//
#ifndef G__TRKUTIL_H
#define G__TRKUTIL_H
//
#include <TVector3.h>
#include <TVectorD.h>
#include <TMatrixDSym.h>
#include <TRandom.h>
#include <TMath.h>
//
//
// Class test

class TrkUtil {
        //
        //
protected:
        Double_t fBz;                                                   // Solenoid magnetic field
        //
        Int_t fGasSel;                                                  // Gas selection: 0: He-Iso, 1: He, 2:Ar-Eth, 3: Ar
        Double_t fRmin;                                                 // Lower                DCH radius
        Double_t fRmax;                                                 // Higher       DCH radius
        Double_t fZmin;                                                 // Lower                DCH z
        Double_t fZmax;                                                 // Higher       DCH z
        //
        // Service routines
        //
        void SetB(Double_t Bz) { fBz = Bz; }
        TVectorD XPtoPar(TVector3 x, TVector3 p, Double_t Q);
        TVector3 ParToP(TVectorD Par);
        TMatrixDSym RegInv(TMatrixDSym& Min);
        //
        // Track trajectory derivatives
        TMatrixD derXdPar(TVectorD par, Double_t s);    // derivatives of position wrt parameters
        TVectorD derXds(TVectorD par, Double_t s);              // derivatives of position wrt phase
        TVectorD dsdPar_R(TVectorD par, Double_t R);    // derivatives of phase at constant R
        TVectorD dsdPar_z(TVectorD par, Double_t z);    // derivatives of phase at constant z
        //
        // Conversion to ACTS parametrization
        //
        TVectorD ParToACTS(TVectorD Par);               // Parameter conversion
        TMatrixDSym CovToACTS(TVectorD Par, TMatrixDSym Cov);   // Covariance conversion
        //
        // Conversion to ILC parametrization
        //
        TVectorD ParToILC(TVectorD Par);                // Parameter conversion
        TMatrixDSym CovToILC(TMatrixDSym Cov);  // Covariance conversion
        //

public:
        //
        // Constructors
        TrkUtil();
        TrkUtil(Double_t Bz);
        // Destructor
        ~TrkUtil();
        //
        // Overload methods to allow call without instantiating class
        //
        static Double_t cSpeed()
        {
                Double_t c = 2.99792458e8;      // speed of light m/sec
                //return TMath::C()*1.0e-9;     // Incompatible with root5
                return c*1.0e-9;                        // Reduced speed of light       
        }
        //
        // Service routines
        //
        static TVectorD XPtoPar(TVector3 x, TVector3 p, Double_t Q, Double_t Bz);
        static TVector3 ParToX(TVectorD Par);                   // position of minimum distance from z axis
        static TVector3 ParToP(TVectorD Par, Double_t Bz);      // Get Momentum from track parameters
        static Double_t ParToQ(TVectorD Par);                   // Get track charge
        static void LineDistance(TVector3 x0, TVector3 y0, TVector3 dirx, TVector3 diry, Double_t &sx, Double_t &sy, Double_t &distance);
        //
        // Track trajectory
        //
        static TVector3 Xtrack(TVectorD par, Double_t s);       // Parametric track trajectory
        TVectorD derRphi_R(TVectorD par, Double_t R);           // Derivatives of R-phi at constant R
        TVectorD derZ_R(TVectorD par, Double_t R);              // Derivatives of z at constant R
        TVectorD derRphi_Z(TVectorD par, Double_t z);           // Derivatives of R-phi at constant z
        TVectorD derR_Z(TVectorD par, Double_t z);              // Derivatives of R at constant z
        //
        // Smear with given covariance matrix
        //
        static TVectorD CovSmear(TVectorD x, TMatrixDSym C);
        //
        // Conversion from meters to mm
        //
        static TVectorD ParToMm(TVectorD Par);                  // Parameter conversion
        static TMatrixDSym CovToMm(TMatrixDSym Cov);            // Covariance conversion
        //
        // Inside cylindrical volume
        //
        static Bool_t IsInside(TVector3 x, Double_t Rout, Double_t Zmin, Double_t Zmax)
        {
                Bool_t Is = kFALSE;
                if (x.Pt() <= Rout && x.z() >= Zmin && x.z() <= Zmax)Is = kTRUE;
                return Is;
        }
        //
        // Cluster counting in gas
        //
        void SetBfield(Double_t Bz) { fBz = Bz; }
        // Define gas volume (units = meters) 
        void SetDchBoundaries(Double_t Rmin, Double_t Rmax, Double_t Zmin, Double_t Zmax);
        // Gas mixture selection
        void SetGasMix(Int_t Opt);
        // Get number of ionization clusters
        Bool_t IonClusters(Double_t &Ncl, Double_t mass, TVectorD Par);
        Double_t Nclusters(Double_t bgam);      // mean clusters/meter vs beta*gamma
        static Double_t Nclusters(Double_t bgam, Int_t Opt);    // mean clusters/meter vs beta*gamma
        Double_t funcNcl(Double_t *xp, Double_t *par);
        Double_t TrkLen(TVectorD Par);                                  // Track length inside chamber
};

#endif