MuonCalib::MuCCaFitter Class Reference

Interface to the straight line fitter for drift circles used by Calib. More...

#include <MuCCaFitter.h>

Inheritance diagram for MuonCalib::MuCCaFitter:

Collaboration diagram for MuonCalib::MuCCaFitter:

Public Types
typedef std::vector< unsigned int >	HitSelection

Public Member Functions
bool	fit (MuonCalibSegment &seg) const
	fit using all hits
bool	fit (MuonCalibSegment &seg, HitSelection selection) const
	fit subset of the hits.
void	printLevel (int level)
	set print level

Private Member Functions
double	getY (const Amg::Vector3D &p) const
	these methods are needed to change the reference frame between the local one of the hit and one used by the fitter: apparently the 2 frames are the same ... TO BE CHECKED!
double	getX (const Amg::Vector3D &p) const
double	getZ (const Amg::Vector3D &p) const
Amg::Vector3D	getVec (double x, double y, double z) const

Private Attributes
bool	m_debug

Detailed Description

Interface to the straight line fitter for drift circles used by Calib.

Author

Fabri.nosp@m.zio..nosp@m.Petru.nosp@m.cci@.nosp@m.cern..nosp@m.ch

Definition at line 29 of file MuCCaFitter.h.

Member Typedef Documentation

HitSelection

typedef std::vector<unsigned int> MuonCalib::IMdtSegmentFitter::HitSelection

inherited

Definition at line 32 of file IMdtSegmentFitter.h.

Member Function Documentation

fit() [1/2]

bool MuonCalib::MuCCaFitter::fit ( MuonCalibSegment & seg ) const

virtual

fit using all hits

Implements MuonCalib::IMdtSegmentFitter.

Definition at line 19 of file MuCCaFitter.cxx.

                                                     {
        // select all hits
        HitSelection selection(seg.mdtHitsOnTrack(), 0);
        // call fit function
        return fit(seg, std::move(selection));
    }

fit() [2/2]

bool MuonCalib::MuCCaFitter::fit ( MuonCalibSegment & seg, HitSelection selection ) const

virtual

fit subset of the hits.

If the HitSelection vector contains a 0 for a given hit the hit is used else the hit is not included in the fit. The size of the HitSelection vector should be equal to the number of hits on track else no fit is performed.

Implements MuonCalib::IMdtSegmentFitter.

Definition at line 26 of file MuCCaFitter.cxx.

                                                                             {
        MsgStream log(Athena::getMessageSvc(), "MuCCaFitter");
        if (log.level() <= MSG::DEBUG) log << MSG::DEBUG << "fit() New seg:" << endmsg;
 
        int N = seg.mdtHitsOnTrack();
 
        if (N < 2) { return false; }
 
        if ((int)selection.size() != N) {
            selection.clear();
            selection.assign(N, 0);
        } else {
            int used(0);
            for (int i = 0; i < N; ++i) {
                if (selection[i] == 0) ++used;
            }
            if (used < 2) {
                log << MSG::WARNING << "fit() TO FEW HITS SELECTED" << endmsg;
                return false;
            }
        }
 
        const Amg::Vector3D& pos = seg.position();
 
        double S(0), Sy(0), Sz(0), Zc{0}, Yc{0};
        std::vector<double> y(N), x(N), z(N);
        std::vector<double> r(N), sr(N), w(N), rw(N);
        int ii{0}, jj{0};
        {
            for (const MuonCalibSegment::MdtHitPtr& hit : seg.mdtHOT()) {
                const MdtCalibHitBase& h = *hit;
                y[ii] = getY(h.localPosition());
                z[ii] = getZ(h.localPosition());
                r[ii] = std::abs(h.driftRadius());
 
                if (h.sigma2DriftRadius() > 0) {
                    w[ii] = 1. / (h.sigma2DriftRadius());
                    sr[ii] = std::sqrt(h.sigma2DriftRadius());
                } else {
                    w[ii] = 0.;
                    sr[ii] = 0.;
                }
                if (log.level() <= MSG::DEBUG)
                    log << MSG::DEBUG << "fit() MuCCaFitter: (" << x[ii] << "," << y[ii] << ")  R = " << r[ii] << " W " << w[ii] << endmsg;
                rw[ii] = r[ii] * w[ii];
                if (selection[jj]) {
                    ++jj;
                    continue;
                }
                S += w[ii];
                Sz += w[ii] * z[ii];
                Sy += w[ii] * y[ii];
                ++ii;
                ++jj;
            }
        }
        if (S == 0)[[unlikely]]{
          log << MSG::ERROR <<"Divisor S is zero."<<endmsg;
          return false;
        }
        Zc = Sz / S;
        Yc = Sy / S;
 
        std::unique_ptr<MuCCaFitterImplementation> Fitter = std::make_unique<MuCCaFitterImplementation>();
        if (log.level() <= MSG::DEBUG) {
            for (int i = 0; i != ii; i++) {
                log << MSG::DEBUG << "fit() MuCCaFitter hits passed to computepam Z=" << x[i] << " phi=" << y[i] << " zzz=" << z[i]
                    << " drift=" << r[i] << " error=" << w[i] << endmsg;
            }
        }
        Fitter->Computeparam3(ii, z, y, r, sr);
        if (log.level() <= MSG::DEBUG) {
            log << MSG::DEBUG << "fit() MuCCaFitter computed track a=" << Fitter->get_a() << " da= " << Fitter->get_da()
                << " b= " << Fitter->get_b() << " db= " << Fitter->get_db() << " corrab= " << Fitter->get_corrab()
                << " chi2f= " << Fitter->get_chi2f() << endmsg;
        }
 
        double afit = Fitter->get_a();
        double chi2f = Fitter->get_chi2f();
 
        std::vector<double> dist(N), ddist(N);
        double R, dis;
        double theta = std::atan(afit);
        if (theta < 0.) theta = M_PI + theta;
        double sinus = std::sin(theta);
        double cosin = std::cos(theta);
        double d = -(getZ(pos) - Zc) * sinus + (getY(pos) - Yc) * cosin;
        if (log.level() <= MSG::DEBUG) {
            log << MSG::DEBUG << "fit() MuCCaFitter>>> theta= " << theta << " sinus= " << sinus << " cosin= " << cosin << endmsg;
            log << MSG::DEBUG << "fit() MuCCaFitter>>> getZ( pos )= " << getZ(pos) << " getY( pos )= " << getY(pos) << " Zc= " << Zc
                << " Yc= " << Yc << endmsg;
        }
        double Syy(0), Szy(0), Syyzz(0), Att(0);
        R = 0;
        for (int i = 0; i < N; ++i) {
            if (selection[i]) continue;
            Syy += (y[i] - Yc) * (y[i] - Yc) * w[i];
            Szy += (y[i] - Yc) * (z[i] - Zc) * w[i];
            Syyzz += ((y[i] - Yc) - (z[i] - Zc)) * ((y[i] - Yc) + (z[i] - Zc)) * w[i];
            dis = (y[i] - Yc) * cosin - (z[i] - Zc) * sinus;
            if (dis > d) {
                R -= rw[i];
            } else {
                R += rw[i];
            }
        }
        Att = Syy + cosin * (2 * sinus * Szy - cosin * Syyzz);
        d = R / S;
        if (log.level() <= MSG::DEBUG){
            log << MSG::DEBUG << "fit() MuCCaFitter>>> d= " << d << " R= " << R << " S= " << S << " Att= " << Att << endmsg;
        }
        if (Att == 0.)[[unlikely]]{
            log << MSG::ERROR << "Divisor Att is zero."<< endmsg;
            return false;
        }
        for (int i = 0; i < N; ++i) {
            if (selection[i]) continue;
            dist[i] = cosin * (y[i] - Yc) - sinus * (z[i] - Zc) - d;
            double dth = -(sinus * (y[i] - Yc) + cosin * (z[i] - Zc)) * (std::sqrt(1. / Att));
            ddist[i] = std::sqrt(dth * dth + (1. / S));
        }
        if (log.level() <= MSG::DEBUG) log << MSG::DEBUG << "fit() Transforming back to real world" << endmsg;
        Amg::Vector3D ndir = getVec(0., sinus, cosin);
        Amg::Vector3D npos = getVec(0., Yc + cosin * d, Zc - sinus * d);
 
        if (log.level() <= MSG::DEBUG)
            log << MSG::DEBUG << "fit() New line: position " << npos << " direction " << ndir << " chi2f " << chi2f << endmsg;
 
        seg.set(chi2f / (N - 2), npos, ndir);
 
        int i{0};
        for (const MuonCalibSegment::MdtHitPtr& hit_ptr : seg.mdtHOT()) {
            hit_ptr->setDistanceToTrack(dist[i], ddist[i]);
            ++i;
        }
 
        if (log.level() <= MSG::DEBUG) log << MSG::DEBUG << "fit() fit done" << endmsg;
        return true;
    }

getVec()

Amg::Vector3D MuonCalib::MuCCaFitter::getVec ( double x, double y, double z ) const

inlineprivate

Definition at line 59 of file MuCCaFitter.h.

{ return Amg::Vector3D(x, z, y); }

getX()

double MuonCalib::MuCCaFitter::getX ( const Amg::Vector3D & p ) const

inlineprivate

Definition at line 57 of file MuCCaFitter.h.

{ return p.x(); }

getY()

double MuonCalib::MuCCaFitter::getY ( const Amg::Vector3D & p ) const

inlineprivate

these methods are needed to change the reference frame between the local one of the hit and one used by the fitter: apparently the 2 frames are the same ... TO BE CHECKED!

!!

Definition at line 56 of file MuCCaFitter.h.

{ return p.z(); }

getZ()

double MuonCalib::MuCCaFitter::getZ ( const Amg::Vector3D & p ) const

inlineprivate

Definition at line 58 of file MuCCaFitter.h.

{ return p.y(); }

printLevel()

void MuonCalib::MuCCaFitter::printLevel ( int level )

virtual

set print level

Implements MuonCalib::IMdtSegmentFitter.

Definition at line 15 of file MuCCaFitter.cxx.

                                          {
        if (level > 0) m_debug = true;
    }

Member Data Documentation

m_debug

bool MuonCalib::MuCCaFitter::m_debug

private

Definition at line 46 of file MuCCaFitter.h.

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The documentation for this class was generated from the following files:

• MuCCaFitter.h
• MuCCaFitter.cxx