AFPFastReco.cxx

Go to the documentation of this file.

/*
 *   Copyright (C) 2002-2025 CERN for the benefit of the ATLAS collaboration
 *   *
 *   *
 *   *       AFPFastReco.cxx
 *   *
 *   *
 *   */
 
#include <Run3AFPMonitoring/AFPFastReco.h>
 
#include <cmath>
 
namespace AFPMon {
 
void AFPFastReco::reco() 
{
    recoClusters();
    recoTracks();
}
 
void AFPFastReco::recoClusters() 
{
    constexpr float dx   = 0.25;  // [mm]
    constexpr float dy   = 0.05;  // [mm]
    constexpr float dz   = 9.00;  // [mm]
    constexpr float tilt = 14. / 180. * M_PI;
 
    std::list toCluster(m_hitContainer->begin(), m_hitContainer->end());
 
    while (!toCluster.empty()) 
    {
        const auto *init = *(toCluster.begin());
        toCluster.pop_front();
        auto clusteredHits = findAround(init, toCluster);
 
        float sumX        = 0;
        float sumY        = 0;
        float sumCharge   = 0;
        int   sumToT_temp = 0;
        for (const xAOD::AFPSiHit* h : clusteredHits) 
        {
            const float charge = h->depositedCharge();
            const float pixX   = dx * h->pixelColIDChip();
            const float pixY   = dy * h->pixelRowIDChip();
            sumX += charge * pixX;
            sumY += charge * pixY;
            sumCharge += charge;
            sumToT_temp += h->timeOverThreshold();
        }
    if (sumCharge == 0.f){
      continue;
    }
        const float xPlane = sumX / sumCharge;
        const float yPlane = sumY / sumCharge;
 
        const int stationID = init->stationID();
        const int layerID   = init->pixelLayerID();
 
        const float x = xPlane;
        const float y = yPlane * std::cos(tilt);
        const float z = yPlane * std::sin(tilt) + dz * layerID;
 
        m_clusters.emplace_back(x, y, z, stationID, layerID, sumToT_temp);
    }
}
 
void AFPFastReco::recoTracks() 
{
    std::list toTrack(m_clusters.begin(), m_clusters.end());
 
    while (!toTrack.empty()) 
    {
        auto init = *(toTrack.begin());
        toTrack.pop_front();
        auto trackCandidate = findAround(init, toTrack);
 
        if (trackCandidate.size() < s_trackSize) continue;
 
        std::array<int, 4> clusters {};
 
        std::vector<std::pair<double, double>> XZ;
        std::vector<std::pair<double, double>> YZ;
 
        for (const auto& cluster : trackCandidate) 
        {
            clusters[cluster.layer]++;
 
            XZ.emplace_back(cluster.x, cluster.z);
            YZ.emplace_back(cluster.y, cluster.z);
        }
 
        const auto [x, xSlope] = linReg(XZ);
        const auto [y, ySlope] = linReg(YZ);
        const int station      = trackCandidate[0].station;
 
        m_tracks.emplace_back(x, y, station, clusters);
    }
}
 
std::pair<double, double> AFPFastReco::linReg(const std::vector<std::pair<double, double>>& YX) const 
{
    double meanx = 0;
    double meany = 0;
    for (const auto& yx : YX) 
    {
        meany += yx.first;
        meanx += yx.second;
    }
 
    meanx /= YX.size();
    meany /= YX.size();
 
    double numerator   = 0;
    double denumerator = 0;
    for (const auto& yx : YX) 
    {
        const double dy = yx.first - meany;
        const double dx = yx.second - meanx;
        numerator += dx * dy;
        denumerator += dx * dx;
    }
 
    if(denumerator==0.0) denumerator=1e-6;
    const double slope    = numerator / denumerator;
    const double position = meany - slope * meanx;
 
    return {position, slope};
}
 
bool AFPFastReco::areNeighbours(const xAOD::AFPSiHit* lhs, const xAOD::AFPSiHit* rhs) const 
{
    if (lhs->stationID() != rhs->stationID()) return false;
    if (lhs->pixelLayerID() != rhs->pixelLayerID()) return false;
    if (lhs->pixelColIDChip() != rhs->pixelColIDChip()) return false;
    if (abs(lhs->pixelRowIDChip() - rhs->pixelRowIDChip()) != 1) return false;
 
    return true;
}
 
bool AFPFastReco::areNeighbours(const AFPCluster& lhs, const AFPCluster& rhs) const 
{
    if (lhs.station != rhs.station) return false;
 
    const float dx = lhs.x - rhs.x;
    const float dy = lhs.y - rhs.y;
    return dx * dx + dy * dy <= s_clusterDistance;
}
 
}  // namespace AFPMon