SimpleRelationFilter.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/vxdHoughTracking/filters/relations/SimpleRelationFilter.h>
#include <tracking/vxdHoughTracking/entities/VXDHoughState.h>
#include <tracking/trackFindingCDC/utilities/StringManipulation.h>
#include <framework/core/ModuleParamList.templateDetails.h>
 
#include <cmath>
 
using namespace Belle2;
using namespace TrackFindingCDC;
using namespace vxdHoughTracking;
 
void SimpleRelationFilter::exposeParameters(ModuleParamList* moduleParamList, const std::string& prefix)
{
  moduleParamList->addParameter(TrackFindingCDC::prefixed(prefix, "simpleThetaCutDeltaL0"), m_SimpleThetaCutDeltaL0,
                                "Simple cut in theta for the overlay region of different ladders in the same layer.",
                                m_SimpleThetaCutDeltaL0);
  moduleParamList->addParameter(TrackFindingCDC::prefixed(prefix, "simpleThetaCutDeltaL1"), m_SimpleThetaCutDeltaL1,
                                "Simple cut in theta for relations between hits with Delta_Layer = +-1.", m_SimpleThetaCutDeltaL1);
  moduleParamList->addParameter(TrackFindingCDC::prefixed(prefix, "simpleThetaCutDeltaL2"), m_SimpleThetaCutDeltaL2,
                                "Simple cut in theta for relations between hits with Delta_Layer = +-2.", m_SimpleThetaCutDeltaL2);
}
 
TrackFindingCDC::Weight
SimpleRelationFilter::operator()(const std::pair<const VXDHoughState*, const VXDHoughState*>& relation)
{
  const VXDHoughState::DataCache& currentVXDHoughState = relation.first->getDataCache();
  const VXDHoughState::DataCache& nextVXDHoughState = relation.second->getDataCache();
 
  const double absThetaDiff = std::abs(currentVXDHoughState.theta - nextVXDHoughState.theta);
 
  // if the connection is possible in u, it should also be possible in v, but as there could in principle be a chance that the hits
  // are on different sensors (X.X.1 -> X.(X+-1).2 or X.X.2 -> X.(X+-1).1) check for a similar theta value instead of v
  if (currentVXDHoughState.layer == nextVXDHoughState.layer) {
    if (absThetaDiff > m_SimpleThetaCutDeltaL0) {
      return NAN;
    }
    // The hits are on the same layer but neighbouring ladders and in the overlap region they are in close proximity in phi.
    // And since they passed the condition above, they are also in close proximity in theta.
    // Thus they are close in phi and should be accepted.
    return 1.0;
  }
 
  const ushort absLayerDiff = std::abs(currentVXDHoughState.layer - nextVXDHoughState.layer);
  if ((absLayerDiff == 1 and absThetaDiff < m_SimpleThetaCutDeltaL1) or
      (absLayerDiff == 2 and absThetaDiff < m_SimpleThetaCutDeltaL2)) {
    return 1.0;
  }
 
  return NAN;
 
}