SimpleSegmentTripleFilter.cc

/**************************************************************************
 * basf2 (Belle II Analysis Software Framework)                           *
 * Author: The Belle II Collaboration                                     *
 *                                                                        *
 * See git log for contributors and copyright holders.                    *
 * This file is licensed under LGPL-3.0, see LICENSE.md.                  *
 **************************************************************************/
#include <tracking/trackFindingCDC/filters/segmentTriple/SimpleSegmentTripleFilter.h>
 
#include <tracking/trackingUtilities/eventdata/tracks/CDCSegmentTriple.h>
#include <tracking/trackingUtilities/eventdata/segments/CDCSegment3D.h>
#include <tracking/trackingUtilities/eventdata/segments/CDCSegment2D.h>
 
#include <tracking/trackingUtilities/eventdata/trajectories/CDCTrajectorySZ.h>
 
#include <cdc/topology/CDCWire.h>
 
#include <framework/logging/Logger.h>
 
#include <Math/Vector3D.h>
 
using namespace Belle2;
using namespace CDC;
using namespace TrackFindingCDC;
using namespace TrackingUtilities;
 
Weight SimpleSegmentTripleFilter::operator()(const CDCSegmentTriple& segmentTriple)
{
  const CDCAxialSegment2D* ptrStartSegment = segmentTriple.getStartSegment();
  const CDCStereoSegment2D* ptrMiddleSegment = segmentTriple.getMiddleSegment();
  const CDCAxialSegment2D* ptrEndSegment = segmentTriple.getEndSegment();
 
  assert(ptrStartSegment);
  assert(ptrMiddleSegment);
  assert(ptrEndSegment);
 
  const CDCAxialSegment2D& startSegment = *ptrStartSegment;
  const CDCStereoSegment2D& middleSegment = *ptrMiddleSegment;
  const CDCAxialSegment2D& endSegment = *ptrEndSegment;
 
  const double toleranceFraction = 0.0;
 
  // Check if the middle segment lies within the acceptable bounds in angular deviation
  {
    //get the remembered fits
    const CDCTrajectory2D& startFit = startSegment.getTrajectory2D();
    const CDCTrajectory2D& endFit = endSegment.getTrajectory2D();
 
    //use only the first and last hit for this check
    const CDCRecoHit2D& firstHit = middleSegment.front();
    const CDCRecoHit2D& lastHit = middleSegment.back();
 
    ROOT::Math::XYZVector firstRecoPos = firstHit.reconstruct3D(startFit);
    ROOT::Math::XYZVector lastRecoPos = lastHit.reconstruct3D(endFit);
 
    const CDCWire& firstWire = firstHit.getWire();
    const CDCWire& lastWire = lastHit.getWire();
 
    const bool agrees =
      firstWire.isInCellZBounds(firstRecoPos, toleranceFraction) and
      lastWire.isInCellZBounds(lastRecoPos, toleranceFraction);
 
    if (not agrees) return NAN;
  }
 
  // make more complex judgement on fitness
 
  // Get the combined fit of start and end axial segment
  CDCTrajectory2D trajectory2D =  getFitter2D().fit(*(segmentTriple.getStartSegment()),
                                                    *(segmentTriple.getEndSegment()));
 
  // Check if the middle segment is actually coaligned with the trajectory
  EForwardBackward fbInfo = trajectory2D.isForwardOrBackwardTo(middleSegment);
  if (fbInfo != EForwardBackward::c_Forward) return NAN;
 
  // Reconstruct the middle stereo segment
  CDCSegment3D reconstructedMiddle;
  for (const CDCRecoHit2D& recoHit2D : middleSegment) {
    reconstructedMiddle.push_back(CDCRecoHit3D::reconstruct(recoHit2D, trajectory2D));
    if (not reconstructedMiddle.back().isInCellZBounds(toleranceFraction)) {
      B2DEBUG(25, "  RecoHit out of CDC");
      return NAN;
    }
  }
 
  // Fit the sz slope and intercept
  CDCTrajectorySZ trajectorySZ;
  getSZFitter().update(trajectorySZ, middleSegment, trajectory2D);
  segmentTriple.setTrajectory3D(CDCTrajectory3D(trajectory2D, trajectorySZ));
 
  Weight result = startSegment.size() + middleSegment.size() + endSegment.size();
 
  return result;
}