PixelTripletNoTipGenerator.cc

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#include "PixelTripletNoTipGenerator.h"
#include "FWCore/Framework/interface/EventSetup.h"
#include "FWCore/ParameterSet/interface/ParameterSet.h"

#include "RecoTracker/TkHitPairs/interface/RecHitsSortedInPhi.h"
#include "FWCore/Framework/interface/Event.h"
#include "RecoTracker/TkMSParametrization/interface/PixelRecoUtilities.h"
#include "ThirdHitPredictionFromInvLine.h"
#include "ThirdHitZPrediction.h"

#include "RecoTracker/TkMSParametrization/interface/MultipleScatteringParametrisation.h"
#include "RecoTracker/TkHitPairs/interface/HitPairGeneratorFromLayerPair.h"

#include "TrackingTools/DetLayers/interface/BarrelDetLayer.h"
#include "TrackingTools/DetLayers/interface/ForwardDetLayer.h"
#include "TrackingTools/DetLayers/interface/DetLayer.h"
#include "DataFormats/GeometrySurface/interface/SimpleDiskBounds.h"

typedef PixelRecoRange<float> Range;
template <class T>
T sqr(T t) {
  return t * t;
}

using namespace std;

PixelTripletNoTipGenerator::PixelTripletNoTipGenerator(const edm::ParameterSet& cfg, edm::ConsumesCollector& iC)
    : HitTripletGeneratorFromPairAndLayers(cfg),
      extraHitRZtolerance(cfg.getParameter<double>("extraHitRZtolerance")),
      extraHitRPhitolerance(cfg.getParameter<double>("extraHitRPhitolerance")),
      extraHitPhiToleranceForPreFiltering(cfg.getParameter<double>("extraHitPhiToleranceForPreFiltering")),
      theNSigma(cfg.getParameter<double>("nSigma")),
      theChi2Cut(cfg.getParameter<double>("chi2Cut")) {}

PixelTripletNoTipGenerator::~PixelTripletNoTipGenerator() {}

void PixelTripletNoTipGenerator::hitTriplets(const TrackingRegion& region,
                                             OrderedHitTriplets& result,
                                             const edm::Event& ev,
                                             const edm::EventSetup& es,
                                             const SeedingLayerSetsHits::SeedingLayerSet& pairLayers,
                                             const std::vector<SeedingLayerSetsHits::SeedingLayer>& thirdLayers) {
  //
  //edm::Handle<reco::BeamSpot> bsHandle;
  //ev.getByLabel( theBeamSpotTag, bsHandle);
  //if(!bsHandle.isValid()) return;
  //const reco::BeamSpot & bs = *bsHandle;
  //double errorXY = sqrt( sqr(bs.BeamWidthX()) + sqr(bs.BeamWidthY()) );
  //

  const GlobalPoint& bsPoint = region.origin();
  double errorXY = region.originRBound();
  GlobalVector shift = bsPoint - GlobalPoint(0., 0., 0.);

  OrderedHitPairs pairs;
  pairs.reserve(30000);
  OrderedHitPairs::const_iterator ip;
  thePairGenerator->hitPairs(region, pairs, ev, es, pairLayers);

  if (pairs.empty())
    return;

  const DetLayer* firstLayer = thePairGenerator->innerLayer(pairLayers).detLayer();
  const DetLayer* secondLayer = thePairGenerator->outerLayer(pairLayers).detLayer();
  if (!firstLayer || !secondLayer)
    return;

  int size = thirdLayers.size();

  const RecHitsSortedInPhi** thirdHitMap = new const RecHitsSortedInPhi*[size];
  for (int il = 0; il <= size - 1; il++) {
    thirdHitMap[il] = &(*theLayerCache)(thirdLayers[il], region, es);
  }

  MultipleScatteringParametrisation sigma1RPhi(firstLayer, es);
  MultipleScatteringParametrisation sigma2RPhi(secondLayer, es);

  typedef RecHitsSortedInPhi::Hit Hit;
  for (ip = pairs.begin(); ip != pairs.end(); ip++) {
    GlobalPoint p1((*ip).inner()->globalPosition() - shift);
    GlobalPoint p2((*ip).outer()->globalPosition() - shift);

    ThirdHitPredictionFromInvLine predictionRPhiTMP(p1, p2);
    double pt_p1p2 = 1. / PixelRecoUtilities::inversePt(predictionRPhiTMP.curvature(), es);

    PixelRecoPointRZ point1(p1.perp(), p1.z());
    PixelRecoPointRZ point2(p2.perp(), p2.z());

    PixelRecoLineRZ line(point1, point2);
    double msRPhi1 = sigma1RPhi(pt_p1p2, line.cotLine(), 0.f);
    double msRPhi2 = sigma2RPhi(pt_p1p2, line.cotLine(), point1);
    double sinTheta = 1 / sqrt(1 + sqr(line.cotLine()));
    double cosTheta = fabs(line.cotLine()) / sqrt(1 + sqr(line.cotLine()));

    double p1_errorRPhi = sqrt(sqr((*ip).inner()->errorGlobalRPhi()) + sqr(msRPhi1) + sqr(errorXY));
    double p2_errorRPhi = sqrt(sqr((*ip).outer()->errorGlobalRPhi()) + sqr(msRPhi2) + sqr(errorXY));

    ThirdHitPredictionFromInvLine predictionRPhi(p1, p2, p1_errorRPhi, p2_errorRPhi);

    for (int il = 0; il <= size - 1; il++) {
      const DetLayer* layer = thirdLayers[il].detLayer();
      bool barrelLayer = (layer->location() == GeomDetEnumerators::barrel);
      MultipleScatteringParametrisation sigma3RPhi(layer, es);
      double msRPhi3 = sigma3RPhi(pt_p1p2, line.cotLine(), point2);

      Range rRange;
      if (barrelLayer) {
        const BarrelDetLayer& bl = dynamic_cast<const BarrelDetLayer&>(*layer);
        float halfThickness = bl.surface().bounds().thickness() / 2;
        float radius = bl.specificSurface().radius();
        rRange = Range(radius - halfThickness, radius + halfThickness);
      } else {
        const ForwardDetLayer& fl = dynamic_cast<const ForwardDetLayer&>(*layer);
        float halfThickness = fl.surface().bounds().thickness() / 2;
        float zLayer = fl.position().z();
        float zMin = zLayer - halfThickness;
        float zMax = zLayer + halfThickness;
        GlobalVector dr = p2 - p1;
        GlobalPoint p3_a = p2 + dr * (zMin - p2.z()) / dr.z();
        GlobalPoint p3_b = p2 + dr * (zMax - p2.z()) / dr.z();
        if (zLayer * p3_a.z() < 0)
          continue;
        rRange = Range(p3_a.perp(), p3_b.perp());
        rRange.sort();
      }
      double displacment = shift.perp();
      GlobalPoint crossing1 = predictionRPhi.crossing(rRange.min() - displacment) + shift;
      GlobalPoint crossing2 = predictionRPhi.crossing(rRange.max() + displacment) + shift;
      float c1_phi = crossing1.phi();
      float c2_phi = crossing2.phi();
      if (c2_phi < c1_phi)
        swap(c1_phi, c2_phi);
      if (c2_phi - c1_phi > M_PI) {
        c2_phi -= 2 * M_PI;
        swap(c1_phi, c2_phi);
      }
      double extraAngle = (displacment + theNSigma * msRPhi3) / rRange.min() + extraHitPhiToleranceForPreFiltering;
      c1_phi -= extraAngle;
      c2_phi += extraAngle;
      vector<Hit> thirdHits = thirdHitMap[il]->hits(c1_phi, c2_phi);

      typedef vector<Hit>::const_iterator IH;
      for (IH th = thirdHits.begin(), eh = thirdHits.end(); th < eh; ++th) {
        GlobalPoint p3((*th)->globalPosition() - shift);
        double p3_errorRPhi = sqrt(sqr((*th)->errorGlobalRPhi()) + sqr(msRPhi3) + sqr(errorXY));

        predictionRPhi.add(p3, p3_errorRPhi);

        double curvature = predictionRPhi.curvature();

        ThirdHitZPrediction zPrediction((*ip).inner()->globalPosition(),
                                        sqrt(sqr((*ip).inner()->errorGlobalR()) + sqr(msRPhi1 / cosTheta)),
                                        sqrt(sqr((*ip).inner()->errorGlobalZ()) + sqr(msRPhi1 / sinTheta)),
                                        (*ip).outer()->globalPosition(),
                                        sqrt(sqr((*ip).outer()->errorGlobalR()) + sqr(msRPhi2 / cosTheta)),
                                        sqrt(sqr((*ip).outer()->errorGlobalZ()) + sqr(msRPhi2 / sinTheta)),
                                        curvature,
                                        theNSigma);
        ThirdHitZPrediction::Range zRange =
            zPrediction((*th)->globalPosition(), sqrt(sqr((*th)->errorGlobalR())) + sqr(msRPhi3 / cosTheta));

        double z3Hit = (*th)->globalPosition().z();
        double z3HitError =
            theNSigma * (sqrt(sqr((*th)->errorGlobalZ()) + sqr(msRPhi3 / sinTheta))) + extraHitRZtolerance;
        Range hitZRange(z3Hit - z3HitError, z3Hit + z3HitError);
        bool inside = hitZRange.hasIntersection(zRange);

        double curvatureMS = PixelRecoUtilities::curvature(1. / region.ptMin(), es);
        bool ptCut = (predictionRPhi.curvature() - theNSigma * predictionRPhi.errorCurvature() < curvatureMS);
        bool chi2Cut = (predictionRPhi.chi2() < theChi2Cut);
        if (inside && ptCut && chi2Cut) {
          if (theMaxElement != 0 && result.size() >= theMaxElement) {
            result.clear();
            edm::LogError("TooManyTriplets") << " number of triples exceed maximum. no triplets produced.";
            delete[] thirdHitMap;
            return;
          }
          result.push_back(OrderedHitTriplet((*ip).inner(), (*ip).outer(), *th));
        }
        predictionRPhi.remove(p3, p3_errorRPhi);
      }
    }
  }
  delete[] thirdHitMap;
}
void PixelTripletNoTipGenerator::hitTriplets(const TrackingRegion& region,
                                             OrderedHitTriplets& result,
                                             const edm::EventSetup& es,
                                             const HitDoublets& doublets,
                                             const RecHitsSortedInPhi** thirdHitMap,
                                             const std::vector<const DetLayer*>& thirdLayerDetLayer,
                                             const int nThirdLayers) {
  throw cms::Exception("Error") << "PixelTripletNoTipGenerator::hitTriplets is not implemented \n";
}