CAHitTripletGenerator.cc

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#include <unordered_map>

#include "CommonTools/Utils/interface/DynArray.h"
#include "DataFormats/Common/interface/Handle.h"
#include "FWCore/Framework/interface/ConsumesCollector.h"
#include "FWCore/Framework/interface/Event.h"
#include "FWCore/ParameterSet/interface/ParameterSetDescription.h"
#include "FWCore/Utilities/interface/isFinite.h"
#include "RecoPixelVertexing/PixelTriplets/interface/CAHitTripletGenerator.h"
#include "RecoPixelVertexing/PixelTriplets/interface/HitTripletGenerator.h"
#include "RecoPixelVertexing/PixelTriplets/interface/ThirdHitPredictionFromCircle.h"
#include "TrackingTools/DetLayers/interface/BarrelDetLayer.h"

#include "CAGraph.h"
#include "CellularAutomaton.h"

namespace
{
  template <typename T>
  T sqr(T x)
  {
    return x * x;
  }
}

using namespace std;

constexpr unsigned int CAHitTripletGenerator::minLayers;

CAHitTripletGenerator::CAHitTripletGenerator(const edm::ParameterSet& cfg,
                                             edm::ConsumesCollector& iC) :
        extraHitRPhitolerance(cfg.getParameter<double>("extraHitRPhitolerance")), //extra window in ThirdHitPredictionFromCircle range (divide by R to get phi)
        maxChi2(cfg.getParameter < edm::ParameterSet > ("maxChi2")),
        useBendingCorrection(cfg.getParameter<bool>("useBendingCorrection")),
        caThetaCut( cfg.getParameter<double>("CAThetaCut")),
        caPhiCut(cfg.getParameter<double>("CAPhiCut")),
        caHardPtCut(cfg.getParameter<double>("CAHardPtCut"))
{
    edm::ParameterSet comparitorPSet = cfg.getParameter < edm::ParameterSet > ("SeedComparitorPSet");
    std::string comparitorName = comparitorPSet.getParameter < std::string > ("ComponentName");
    if (comparitorName != "none")
    {
        theComparitor.reset(
                SeedComparitorFactory::get()->create(comparitorName,
                        comparitorPSet, iC));
    }
}

void CAHitTripletGenerator::fillDescriptions(edm::ParameterSetDescription& desc) {
  desc.add<double>("extraHitRPhitolerance", 0.06);
  desc.add<bool>("useBendingCorrection", false);
  desc.add<double>("CAThetaCut", 0.00125);
  desc.add<double>("CAPhiCut", 0.1);
  desc.add<double>("CAHardPtCut", 0);

  edm::ParameterSetDescription descMaxChi2;
  descMaxChi2.add<double>("pt1", 0.8);
  descMaxChi2.add<double>("pt2", 2);
  descMaxChi2.add<double>("value1", 50);
  descMaxChi2.add<double>("value2", 8);
  descMaxChi2.add<bool>("enabled", true);
  desc.add<edm::ParameterSetDescription>("maxChi2", descMaxChi2);

  edm::ParameterSetDescription descComparitor;
  descComparitor.add<std::string>("ComponentName", "none");
  descComparitor.setAllowAnything(); // until we have moved SeedComparitor too to EDProducers
  desc.add<edm::ParameterSetDescription>("SeedComparitorPSet", descComparitor);
}

void CAHitTripletGenerator::initEvent(const edm::Event& ev, const edm::EventSetup& es) {
  if (theComparitor) theComparitor->init(ev, es);
}

namespace {
  void createGraphStructure(const SeedingLayerSetsHits& layers, CAGraph& g) {
    for (unsigned int i = 0; i < layers.size(); i++)
    {
        for (unsigned int j = 0; j < 3; ++j)
        {
            auto vertexIndex = 0;
            auto foundVertex = std::find(g.theLayers.begin(), g.theLayers.end(),
                    layers[i][j].name());
            if (foundVertex == g.theLayers.end())
            {
                g.theLayers.emplace_back(layers[i][j].name(),
                            layers[i][j].hits().size());
                vertexIndex = g.theLayers.size() - 1;
            }
            else
            {
                vertexIndex = foundVertex - g.theLayers.begin();
            }
            if (j == 0)
            {

                if (std::find(g.theRootLayers.begin(), g.theRootLayers.end(),
                        vertexIndex) == g.theRootLayers.end())
                {
                    g.theRootLayers.emplace_back(vertexIndex);

                }

            }
        }
    }
  }

  void clearGraphStructure(const SeedingLayerSetsHits& layers, CAGraph& g) {
    g.theLayerPairs.clear();
    for (unsigned int i = 0; i < g.theLayers.size(); i++ ){
        g.theLayers[i].theInnerLayers.clear();
        g.theLayers[i].theInnerLayerPairs.clear();
        g.theLayers[i].theOuterLayers.clear();
        g.theLayers[i].theOuterLayerPairs.clear();
        for (auto & v : g.theLayers[i].isOuterHitOfCell) v.clear();
    }

  }
  
  void fillGraph(const SeedingLayerSetsHits& layers, const IntermediateHitDoublets::RegionLayerSets& regionLayerPairs,
                 CAGraph& g, std::vector<const HitDoublets *>& hitDoublets) {
    for (unsigned int i = 0; i < layers.size(); i++)
    {
        for (unsigned int j = 0; j < 3; ++j)
        {
            auto vertexIndex = 0;
            auto foundVertex = std::find(g.theLayers.begin(), g.theLayers.end(),
                    layers[i][j].name());

            if (foundVertex == g.theLayers.end())
            {
                vertexIndex = g.theLayers.size() - 1;
            }
            else
            {
                vertexIndex = foundVertex - g.theLayers.begin();
            }
        
            
            if (j > 0)
            {

                auto innerVertex = std::find(g.theLayers.begin(),
                        g.theLayers.end(), layers[i][j - 1].name());

                CALayerPair tmpInnerLayerPair(innerVertex - g.theLayers.begin(),
                        vertexIndex);

                if (std::find(g.theLayerPairs.begin(), g.theLayerPairs.end(),
                        tmpInnerLayerPair) == g.theLayerPairs.end())
                {
                    auto found = std::find_if(regionLayerPairs.begin(), regionLayerPairs.end(), [&](const IntermediateHitDoublets::LayerPairHitDoublets& pair) {
                      return pair.innerLayerIndex() == layers[i][j - 1].index() && pair.outerLayerIndex() == layers[i][j].index();
                    });
                                        if(found != regionLayerPairs.end()) {
                                          hitDoublets.emplace_back(&(found->doublets()));
                                          g.theLayerPairs.push_back(tmpInnerLayerPair);
                                          g.theLayers[vertexIndex].theInnerLayers.push_back(
                            innerVertex - g.theLayers.begin());
                                          innerVertex->theOuterLayers.push_back(vertexIndex);
                                          g.theLayers[vertexIndex].theInnerLayerPairs.push_back(
                            g.theLayerPairs.size() - 1);
                                          innerVertex->theOuterLayerPairs.push_back(
                            g.theLayerPairs.size() - 1);
                                        }
                }

            }

        }
    }
  }
}

void CAHitTripletGenerator::hitNtuplets(const IntermediateHitDoublets& regionDoublets,
                                        std::vector<OrderedHitSeeds>& result,
                                        const edm::EventSetup& es,
                                        const SeedingLayerSetsHits& layers) {
  CAGraph g;

  std::vector<const HitDoublets *> hitDoublets;

  std::vector<CACell::CAntuplet> foundTriplets;

  int index =0;
  for(const auto& regionLayerPairs: regionDoublets) {

    const TrackingRegion& region = regionLayerPairs.region();
    hitDoublets.clear(); 
    foundTriplets.clear();
 
    if (index == 0){   
        createGraphStructure(layers, g);
    }
    else{  
        clearGraphStructure(layers, g);
    }
    fillGraph(layers, regionLayerPairs, g, hitDoublets);
    CellularAutomaton ca(g);
    ca.findTriplets(hitDoublets, foundTriplets, region, caThetaCut, caPhiCut,
                        caHardPtCut);

    auto & allCells = ca.getAllCells();

    const QuantityDependsPtEval maxChi2Eval = maxChi2.evaluator(es);

    // re-used thoughout, need to be vectors because of RZLine interface
    std::array<float, 3> bc_r;
    std::array<float, 3> bc_z;
    std::array<float, 3> bc_errZ2;
    std::array<GlobalPoint, 3> gps;
    std::array<GlobalError, 3> ges;
    std::array<bool, 3> barrels;
    
    unsigned int numberOfFoundTriplets = foundTriplets.size();
    for (unsigned int tripletId = 0; tripletId < numberOfFoundTriplets;
            ++tripletId)
    {

        OrderedHitTriplet tmpTriplet(allCells[foundTriplets[tripletId][0]].getInnerHit(),
                allCells[foundTriplets[tripletId][0]].getOuterHit(),
                allCells[foundTriplets[tripletId][1]].getOuterHit());

        auto isBarrel = [](const unsigned id) -> bool
        {
            return id == PixelSubdetector::PixelBarrel;
        };
        for (unsigned int i = 0; i < 2; ++i)
        {
            auto const& ahit = allCells[foundTriplets[tripletId][i]].getInnerHit();
            gps[i] = ahit->globalPosition();
            ges[i] = ahit->globalPositionError();
            barrels[i] = isBarrel(ahit->geographicalId().subdetId());
        }

        auto const& ahit = allCells[foundTriplets[tripletId][1]].getOuterHit();
        gps[2] = ahit->globalPosition();
        ges[2] = ahit->globalPositionError();
        barrels[2] = isBarrel(ahit->geographicalId().subdetId());

        PixelRecoLineRZ line(gps[0], gps[2]);
        ThirdHitPredictionFromCircle predictionRPhi(gps[0], gps[2],
                extraHitRPhitolerance);
        const float curvature = predictionRPhi.curvature(
                ThirdHitPredictionFromCircle::Vector2D(gps[1].x(), gps[1].y()));
        const float abscurv = std::abs(curvature);
        const float thisMaxChi2 = maxChi2Eval.value(abscurv);
        float chi2 = std::numeric_limits<float>::quiet_NaN();
        // TODO: Do we have any use case to not use bending correction?

        if (useBendingCorrection)
        {
            // Following PixelFitterByConformalMappingAndLine
            const float simpleCot = (gps.back().z() - gps.front().z())
                    / (gps.back().perp() - gps.front().perp());
            const float pt = 1.f / PixelRecoUtilities::inversePt(abscurv, es);
            for (int i = 0; i < 3; ++i)
            {
                const GlobalPoint & point = gps[i];
                const GlobalError & error = ges[i];
                bc_r[i] = sqrt(
                        sqr(point.x() - region.origin().x())
                                + sqr(point.y() - region.origin().y()));
                bc_r[i] += pixelrecoutilities::LongitudinalBendingCorrection(pt,
                        es)(bc_r[i]);
                bc_z[i] = point.z() - region.origin().z();
                bc_errZ2[i] =
                        (barrels[i]) ?
                                error.czz() :
                                error.rerr(point) * sqr(simpleCot);
            }
            RZLine rzLine(bc_r, bc_z, bc_errZ2, RZLine::ErrZ2_tag());
            chi2 = rzLine.chi2();
        }
        else
        {
            RZLine rzLine(gps, ges, barrels);
            chi2 = rzLine.chi2();
        }

        if (edm::isNotFinite(chi2) || chi2 > thisMaxChi2)
        {
            continue;

        }

        if (theComparitor)
        {
            if (!theComparitor->compatible(tmpTriplet))
            {

                continue;
            }
        }
        result[index].emplace_back(tmpTriplet);

    }
    index++;
    }
}