RecoComposite.cc

/**************************************************************************
 * BASF2 (Belle Analysis Framework 2)                                     *
 * Copyright(C) 2018 - Belle II Collaboration                             *
 *                                                                        *
 * Author: The Belle II Collaboration                                     *
 * Contributor: Wouter Hulsbergen, Francesco Tenchini, Jo-Frederik Krohn  *
 *                                                                        *
 * This software is provided "as is" without any warranty.                *
 **************************************************************************/
 
 
#include <analysis/VertexFitting/TreeFitter/RecoComposite.h>
#include <analysis/VertexFitting/TreeFitter/FitParams.h>
 
#include <TMatrixFSym.h>
 
namespace TreeFitter {
 
  RecoComposite::RecoComposite(Belle2::Particle* particle, const ParticleBase* mother)
    : ParticleBase(particle, mother), m_params(), m_hasEnergy(true)
  {
    updateParams();
  }
 
  ErrCode RecoComposite::initParticleWithMother(FitParams& fitparams)
  {
    return initTau(fitparams);
  }
 
  ErrCode RecoComposite::initMotherlessParticle(FitParams& fitparams)
  {
    const int posindex = posIndex();
    const int momindex = momIndex();
 
    fitparams.getStateVector().segment(posindex, 3) = m_params.segment(0, 3);
 
    fitparams.getStateVector().segment(momindex, 4) = m_params.segment(3, 4);
 
    return ErrCode(ErrCode::Status::success) ;
  }
 
  void RecoComposite::updateParams()
  {
    const TVector3 pos = particle()->getVertex();
    const TVector3 mom = particle()->getMomentum();
    const double energy = particle()->getEnergy();
 
    m_params = Eigen::Matrix<double, 7, 1>::Zero(7, 1);
    m_params(0) = pos.X();
    m_params(1) = pos.Y();
    m_params(2) = pos.Z();
    m_params(3) = mom.X();
    m_params(4) = mom.Y();
    m_params(5) = mom.Z();
 
    m_params(6) = energy;
 
    m_covariance = Eigen::Matrix < double, -1, -1, 0, 7, 7 >::Zero(7, 7);
    const TMatrixFSym cov7in = particle()->getMomentumVertexErrorMatrix(); //this is (p,E,x)
 
    for (int row = 0; row < 4; ++row) { //first the p,E block
      for (int col = 0; col <= row; ++col) {
        m_covariance(3 + row, 3 + col) = cov7in[row][col];
      }
    }
 
    for (int row = 0; row < 3; ++row) { //then the x block
      for (int col = 0; col <= row; ++col) {
        m_covariance(row, col) = cov7in[3 + row][3 + col];
      }
    }
  }
 
  ErrCode RecoComposite::projectRecoComposite(const FitParams& fitparams, Projection& p) const
  {
    const int posindex = posIndex() ;
    const int momindex = momIndex() ;
 
    p.getResiduals().segment(0, 3) = m_params.segment(0, 3) - fitparams.getStateVector().segment(posindex, 3);
 
    p.getResiduals().segment(3, 4) = m_params.segment(3, 4) - fitparams.getStateVector().segment(momindex, 4);
 
    for (int row = 0; row < 3; ++row) {
      p.getH()(row,  posindex + row) = -1;
    }
 
    for (int row = 0; row < 4; ++row) {
      p.getH()(3 + row,  momindex + row) = -1;
    }
 
    p.getV().triangularView<Eigen::Lower>() = m_covariance.triangularView<Eigen::Lower>();
 
    return ErrCode(ErrCode::Status::success) ;
  }
 
  ErrCode RecoComposite::projectConstraint(Constraint::Type type, const FitParams& fitparams, Projection& p) const
  {
    ErrCode status;
    switch (type) {
      case Constraint::composite:
        status |= projectRecoComposite(fitparams, p);
        break ;
      case Constraint::geometric:
        status |= projectGeoConstraint(fitparams, p);
        break ;
      default:
        status |= ParticleBase::projectConstraint(type, fitparams, p);
    }
    return status ;
  }
 
}