PixelTriplets/plugins/PixelTripletLargeTipGenerator.cc

0001 #include "RecoPixelVertexing/PixelTriplets/plugins/PixelTripletLargeTipGenerator.h"
0002 #include "RecoTracker/TkHitPairs/interface/HitPairGeneratorFromLayerPair.h"
0003 #include "FWCore/Framework/interface/ConsumesCollector.h"
0004
0005 #include "RecoPixelVertexing/PixelTriplets/interface/ThirdHitPredictionFromCircle.h"
0006 #include "RecoPixelVertexing/PixelTriplets/interface/ThirdHitRZPrediction.h"
0007 #include "RecoTracker/TkMSParametrization/interface/PixelRecoUtilities.h"
0008 #include "FWCore/Framework/interface/ConsumesCollector.h"
0009 #include "FWCore/Framework/interface/EventSetup.h"
0010 #include "FWCore/ParameterSet/interface/ParameterSet.h"
0011 #include "FWCore/ParameterSet/interface/ParameterSetDescription.h"
0012
0013 #include "RecoPixelVertexing/PixelTriplets/plugins/ThirdHitCorrection.h"
0014 #include "RecoTracker/TkHitPairs/interface/RecHitsSortedInPhi.h"
0015
0016 #include "MatchedHitRZCorrectionFromBending.h"
0017 #include "CommonTools/RecoAlgos/interface/KDTreeLinkerAlgo.h"
0018
0019 #include <algorithm>
0020 #include <iostream>
0021 #include <vector>
0022 #include <cmath>
0023 #include <map>
0024
0025 #include "DataFormats/Math/interface/normalizedPhi.h"
0026
0027 #include "CommonTools/Utils/interface/DynArray.h"
0028
0029 using namespace std;
0030
0031 using Range = PixelRecoRange<float>;
0032 using HelixRZ = ThirdHitPredictionFromCircle::HelixRZ;
0033
0034 namespace {
0035   struct LayerRZPredictions {
0036     ThirdHitRZPrediction<PixelRecoLineRZ> line;
0037     ThirdHitRZPrediction<HelixRZ> helix1, helix2;
0038     MatchedHitRZCorrectionFromBending rzPositionFixup;
0039     ThirdHitCorrection correction;
0040   };
0041 }  // namespace
0042
0043 constexpr double nSigmaRZ = 3.4641016151377544;  // sqrt(12.)
0044 constexpr float nSigmaPhi = 3.;
0045 constexpr float fnSigmaRZ = nSigmaRZ;
0046
0047 PixelTripletLargeTipGenerator::PixelTripletLargeTipGenerator(const edm::ParameterSet& cfg, edm::ConsumesCollector& iC)
0048     : HitTripletGeneratorFromPairAndLayers(cfg),
0049       useFixedPreFiltering(cfg.getParameter<bool>("useFixedPreFiltering")),
0050       extraHitRZtolerance(cfg.getParameter<double>("extraHitRZtolerance")),
0051       extraHitRPhitolerance(cfg.getParameter<double>("extraHitRPhitolerance")),
0052       useMScat(cfg.getParameter<bool>("useMultScattering")),
0053       useBend(cfg.getParameter<bool>("useBending")),
0054       dphi(useFixedPreFiltering ? cfg.getParameter<double>("phiPreFiltering") : 0),
0055       trackerTopologyESToken_(iC.esConsumes()),
0056       fieldESToken_(iC.esConsumes()) {
0057   if (useMScat) {
0058     msmakerESToken_ = iC.esConsumes();
0059   }
0060 }
0061
0062 PixelTripletLargeTipGenerator::~PixelTripletLargeTipGenerator() {}
0063
0064 void PixelTripletLargeTipGenerator::fillDescriptions(edm::ParameterSetDescription& desc) {
0065   HitTripletGeneratorFromPairAndLayers::fillDescriptions(desc);
0066   // Defaults for the extraHit*tolerance are set to 0 here since that
0067   // was already the case in practice in all offline occurrances.
0068   desc.add<double>("extraHitRPhitolerance", 0);  // default in old python was 0.032
0069   desc.add<double>("extraHitRZtolerance", 0);    // default in old python was 0.037
0070   desc.add<bool>("useMultScattering", true);
0071   desc.add<bool>("useBending", true);
0072   desc.add<bool>("useFixedPreFiltering", false);
0073   desc.add<double>("phiPreFiltering", 0.3);
0074 }
0075
0076 namespace {
0077   inline bool intersect(Range& range, const Range& second) {
0078     if ((range.min() > second.max()) | (range.max() < second.min()))
0079       return false;
0080     if (range.first < second.min())
0081       range.first = second.min();
0082     if (range.second > second.max())
0083       range.second = second.max();
0084     return range.first < range.second;
0085   }
0086 }  // namespace
0087
0088 void PixelTripletLargeTipGenerator::hitTriplets(const TrackingRegion& region,
0089                                                 OrderedHitTriplets& result,
0090                                                 const edm::Event& ev,
0091                                                 const edm::EventSetup& es,
0092                                                 const SeedingLayerSetsHits::SeedingLayerSet& pairLayers,
0093                                                 const std::vector<SeedingLayerSetsHits::SeedingLayer>& thirdLayers) {
0094   auto const& doublets = thePairGenerator->doublets(region, ev, es, pairLayers);
0095
0096   if (doublets.empty())
0097     return;
0098
0099   assert(theLayerCache);
0100   hitTriplets(region, result, ev, es, doublets, thirdLayers, nullptr, *theLayerCache);
0101 }
0102
0103 void PixelTripletLargeTipGenerator::hitTriplets(const TrackingRegion& region,
0104                                                 OrderedHitTriplets& result,
0105                                                 const edm::Event& ev,
0106                                                 const edm::EventSetup& es,
0107                                                 const HitDoublets& doublets,
0108                                                 const std::vector<SeedingLayerSetsHits::SeedingLayer>& thirdLayers,
0109                                                 std::vector<int>* tripletLastLayerIndex,
0110                                                 LayerCacheType& layerCache) {
0111   int size = thirdLayers.size();
0112   const RecHitsSortedInPhi* thirdHitMap[size];
0113   vector<const DetLayer*> thirdLayerDetLayer(size, nullptr);
0114   for (int il = 0; il < size; ++il) {
0115     thirdHitMap[il] = &layerCache(thirdLayers[il], region);
0116     thirdLayerDetLayer[il] = thirdLayers[il].detLayer();
0117   }
0118   hitTriplets(region, result, es, doublets, thirdHitMap, thirdLayerDetLayer, size, tripletLastLayerIndex);
0119 }
0120
0121 void PixelTripletLargeTipGenerator::hitTriplets(const TrackingRegion& region,
0122                                                 OrderedHitTriplets& result,
0123                                                 const edm::EventSetup& es,
0124                                                 const HitDoublets& doublets,
0125                                                 const RecHitsSortedInPhi** thirdHitMap,
0126                                                 const std::vector<const DetLayer*>& thirdLayerDetLayer,
0127                                                 const int nThirdLayers) {
0128   hitTriplets(region, result, es, doublets, thirdHitMap, thirdLayerDetLayer, nThirdLayers, nullptr);
0129 }
0130
0131 void PixelTripletLargeTipGenerator::hitTriplets(const TrackingRegion& region,
0132                                                 OrderedHitTriplets& result,
0133                                                 const edm::EventSetup& es,
0134                                                 const HitDoublets& doublets,
0135                                                 const RecHitsSortedInPhi** thirdHitMap,
0136                                                 const std::vector<const DetLayer*>& thirdLayerDetLayer,
0137                                                 const int nThirdLayers,
0138                                                 std::vector<int>* tripletLastLayerIndex) {
0139   const TrackerTopology* tTopo = &es.getData(trackerTopologyESToken_);
0140   const auto& field = es.getData(fieldESToken_);
0141   const MultipleScatteringParametrisationMaker* msmaker = nullptr;
0142   if (useMScat) {
0143     msmaker = &es.getData(msmakerESToken_);
0144   }
0145
0146   auto outSeq = doublets.detLayer(HitDoublets::outer)->seqNum();
0147
0148   using NodeInfo = KDTreeNodeInfo<unsigned int, 2>;
0149   std::vector<NodeInfo> layerTree;       // re-used throughout
0150   std::vector<unsigned int> foundNodes;  // re-used throughout
0151   foundNodes.reserve(100);
0152
0153   declareDynArray(KDTreeLinkerAlgo<unsigned int>, nThirdLayers, hitTree);
0154   declareDynArray(LayerRZPredictions, nThirdLayers, mapPred);
0155
0156   float rzError[nThirdLayers];  //save maximum errors
0157
0158   const float maxDelphi = region.ptMin() < 0.3f ? float(M_PI) / 4.f : float(M_PI) / 8.f;  // FIXME move to config??
0159   const float maxphi = M_PI + maxDelphi, minphi = -maxphi;  // increase to cater for any range
0160   const float safePhi = M_PI - maxDelphi;                   // sideband
0161
0162   for (int il = 0; il < nThirdLayers; il++) {
0163     auto const& hits = *thirdHitMap[il];
0164
0165     const DetLayer* layer = thirdLayerDetLayer[il];
0166     LayerRZPredictions& predRZ = mapPred[il];
0167     predRZ.line.initLayer(layer);
0168     predRZ.helix1.initLayer(layer);
0169     predRZ.helix2.initLayer(layer);
0170     predRZ.line.initTolerance(extraHitRZtolerance);
0171     predRZ.helix1.initTolerance(extraHitRZtolerance);
0172     predRZ.helix2.initTolerance(extraHitRZtolerance);
0173     predRZ.rzPositionFixup = MatchedHitRZCorrectionFromBending(layer, tTopo);
0174     predRZ.correction.init(region.ptMin(),
0175                            *doublets.detLayer(HitDoublets::inner),
0176                            *doublets.detLayer(HitDoublets::outer),
0177                            *thirdLayerDetLayer[il],
0178                            useMScat,
0179                            msmaker,
0180                            false,
0181                            nullptr);
0182
0183     layerTree.clear();
0184     float minv = 999999.0;
0185     float maxv = -999999.0;  // Initialise to extreme values in case no hits
0186     float maxErr = 0.0f;
0187     for (unsigned int i = 0; i != hits.size(); ++i) {
0188       auto angle = hits.phi(i);
0189       auto v = hits.gv(i);
0190       //use (phi,r) for endcaps rather than (phi,z)
0191       minv = std::min(minv, v);
0192       maxv = std::max(maxv, v);
0193       float myerr = hits.dv[i];
0194       maxErr = std::max(maxErr, myerr);
0195       layerTree.emplace_back(i, angle, v);  // save it
0196       // populate side-bands
0197       if (angle > safePhi)
0198         layerTree.emplace_back(i, angle - Geom::ftwoPi(), v);
0199       else if (angle < -safePhi)
0200         layerTree.emplace_back(i, angle + Geom::ftwoPi(), v);
0201     }
0202     KDTreeBox phiZ(minphi, maxphi, minv - 0.01f, maxv + 0.01f);  // declare our bounds
0203     //add fudge factors in case only one hit and also for floating-point inaccuracy
0204     hitTree[il].build(layerTree, phiZ);  // make KDtree
0205     rzError[il] = maxErr;                //save error
0206   }
0207
0208   double curv = PixelRecoUtilities::curvature(1. / region.ptMin(), field);
0209
0210   for (std::size_t ip = 0; ip != doublets.size(); ip++) {
0211     auto xi = doublets.x(ip, HitDoublets::inner);
0212     auto yi = doublets.y(ip, HitDoublets::inner);
0213     auto zi = doublets.z(ip, HitDoublets::inner);
0214     // auto rvi = doublets.rv(ip,HitDoublets::inner);
0215     auto xo = doublets.x(ip, HitDoublets::outer);
0216     auto yo = doublets.y(ip, HitDoublets::outer);
0217     auto zo = doublets.z(ip, HitDoublets::outer);
0218     // auto rvo = doublets.rv(ip,HitDoublets::outer);
0219     GlobalPoint gp1(xi, yi, zi);
0220     GlobalPoint gp2(xo, yo, zo);
0221
0222     auto toPos = std::signbit(zo - zi);
0223
0224     PixelRecoLineRZ line(gp1, gp2);
0225     PixelRecoPointRZ point2(gp2.perp(), zo);
0226     ThirdHitPredictionFromCircle predictionRPhi(gp1, gp2, extraHitRPhitolerance);
0227
0228     Range generalCurvature = predictionRPhi.curvature(region.originRBound());
0229     if (!intersect(generalCurvature, Range(-curv, curv)))
0230       continue;
0231
0232     for (int il = 0; il < nThirdLayers; il++) {
0233       if (hitTree[il].empty())
0234         continue;  // Don't bother if no hits
0235       const DetLayer* layer = thirdLayerDetLayer[il];
0236       bool barrelLayer = layer->isBarrel();
0237
0238       if ((!barrelLayer) & (toPos != std::signbit(layer->position().z())))
0239         continue;
0240
0241       Range curvature = generalCurvature;
0242
0243       LayerRZPredictions& predRZ = mapPred[il];
0244       predRZ.line.initPropagator(&line);
0245
0246       auto& correction = predRZ.correction;
0247       correction.init(line, point2, outSeq);
0248
0249       Range rzRange;
0250       if (useBend) {
0251         // For the barrel region:
0252         // swiping the helix passing through the two points across from
0253         // negative to positive bending, can give us a sort of U-shaped
0254         // projection onto the phi-z (barrel) or r-z plane (forward)
0255         // so we checking minimum/maximum of all three possible extrema
0256         //
0257         // For the endcap region:
0258         // Checking minimum/maximum radius of the helix projection
0259         // onto an endcap plane, here we have to guard against
0260         // looping tracks, when phi(delta z) gets out of control.
0261         // HelixRZ::rAtZ should not follow looping tracks, but clamp
0262         // to the minimum reachable r with the next-best lower |curvature|.
0263         // So same procedure as for the barrel region can be applied.
0264         //
0265         // In order to avoid looking for potential looping tracks at all
0266         // we also clamp the allowed curvature range for this layer,
0267         // and potentially fail the layer entirely
0268
0269         if (!barrelLayer) {
0270           Range z3s = predRZ.line.detRange();
0271           double z3 = z3s.first < 0 ? std::max(z3s.first, z3s.second) : std::min(z3s.first, z3s.second);
0272           double maxCurvature = HelixRZ::maxCurvature(&predictionRPhi, gp1.z(), gp2.z(), z3);
0273           if (!intersect(curvature, Range(-maxCurvature, maxCurvature)))
0274             continue;
0275         }
0276
0277         HelixRZ helix1(&predictionRPhi, gp1.z(), gp2.z(), curvature.first);
0278         HelixRZ helix2(&predictionRPhi, gp1.z(), gp2.z(), curvature.second);
0279
0280         predRZ.helix1.initPropagator(&helix1);
0281         predRZ.helix2.initPropagator(&helix2);
0282
0283         Range rzRanges[2] = {predRZ.helix1(), predRZ.helix2()};
0284         predRZ.helix1.initPropagator(nullptr);
0285         predRZ.helix2.initPropagator(nullptr);
0286
0287         rzRange.first = std::min(rzRanges[0].first, rzRanges[1].first);
0288         rzRange.second = std::max(rzRanges[0].second, rzRanges[1].second);
0289
0290         // if the allowed curvatures include a straight line,
0291         // this can give us another extremum for allowed r/z
0292         if (curvature.first * curvature.second < 0.0) {
0293           Range rzLineRange = predRZ.line();
0294           rzRange.first = std::min(rzRange.first, rzLineRange.first);
0295           rzRange.second = std::max(rzRange.second, rzLineRange.second);
0296         }
0297       } else {
0298         rzRange = predRZ.line();
0299       }
0300
0301       if (rzRange.first >= rzRange.second)
0302         continue;
0303
0304       correction.correctRZRange(rzRange);
0305
0306       Range phiRange;
0307       if (useFixedPreFiltering) {
0308         float phi0 = doublets.phi(ip, HitDoublets::outer);
0309         phiRange = Range(phi0 - dphi, phi0 + dphi);
0310       } else {
0311         Range radius;
0312
0313         if (barrelLayer) {
0314           radius = predRZ.line.detRange();
0315           if (!intersect(rzRange, predRZ.line.detSize()))
0316             continue;
0317         } else {
0318           radius = rzRange;
0319           if (!intersect(radius, predRZ.line.detSize()))
0320             continue;
0321         }
0322
0323         //gc: predictionRPhi uses the cosine rule to find the phi of the 3rd point at radius, assuming the pairCurvature range [-c,+c]
0324         if ((curvature.first < 0.0f) & (curvature.second < 0.0f)) {
0325           radius.swap();
0326         } else if ((curvature.first >= 0.0f) & (curvature.second >= 0.0f)) {
0327           ;
0328         } else {
0329           radius.first = radius.second;
0330         }
0331         auto phi12 = predictionRPhi.phi(curvature.first, radius.first);
0332         auto phi22 = predictionRPhi.phi(curvature.second, radius.second);
0333         phi12 = normalizedPhi(phi12);
0334         phi22 = proxim(phi22, phi12);
0335         phiRange = Range(phi12, phi22);
0336         phiRange.sort();
0337         auto rmean = radius.mean();
0338         phiRange.first *= rmean;
0339         phiRange.second *= rmean;
0340         correction.correctRPhiRange(phiRange);
0341         phiRange.first /= rmean;
0342         phiRange.second /= rmean;
0343       }
0344
0345       foundNodes.clear();                                    // Now recover hits in bounding box...
0346       float prmin = phiRange.min(), prmax = phiRange.max();  //get contiguous range
0347
0348       if (prmax - prmin > maxDelphi) {
0349         auto prm = phiRange.mean();
0350         prmin = prm - 0.5f * maxDelphi;
0351         prmax = prm + 0.5f * maxDelphi;
0352       }
0353
0354       if (barrelLayer) {
0355         Range regMax = predRZ.line.detRange();
0356         Range regMin = predRZ.line(regMax.min());
0357         regMax = predRZ.line(regMax.max());
0358         correction.correctRZRange(regMin);
0359         correction.correctRZRange(regMax);
0360         if (regMax.min() < regMin.min()) {
0361           std::swap(regMax, regMin);
0362         }
0363         KDTreeBox phiZ(prmin, prmax, regMin.min() - fnSigmaRZ * rzError[il], regMax.max() + fnSigmaRZ * rzError[il]);
0364         hitTree[il].search(phiZ, foundNodes);
0365       } else {
0366         KDTreeBox phiZ(prmin, prmax, rzRange.min() - fnSigmaRZ * rzError[il], rzRange.max() + fnSigmaRZ * rzError[il]);
0367         hitTree[il].search(phiZ, foundNodes);
0368       }
0369
0370       MatchedHitRZCorrectionFromBending l2rzFixup(doublets.hit(ip, HitDoublets::outer)->det()->geographicalId(), tTopo);
0371       MatchedHitRZCorrectionFromBending l3rzFixup = predRZ.rzPositionFixup;
0372
0373       auto const& hits = *thirdHitMap[il];
0374       for (auto KDdata : foundNodes) {
0375         GlobalPoint p3 = hits.gp(KDdata);
0376         double p3_r = p3.perp();
0377         double p3_z = p3.z();
0378         float p3_phi = hits.phi(KDdata);
0379
0380         Range rangeRPhi = predictionRPhi(curvature, p3_r);
0381         correction.correctRPhiRange(rangeRPhi);
0382
0383         float ir = 1.f / p3_r;
0384         // limit error to 90 degree
0385         constexpr float maxPhiErr = 0.5 * M_PI;
0386         float phiErr = nSigmaPhi * hits.drphi[KDdata] * ir;
0387         phiErr = std::min(maxPhiErr, phiErr);
0388         if (!checkPhiInRange(p3_phi, rangeRPhi.first * ir - phiErr, rangeRPhi.second * ir + phiErr, maxPhiErr))
0389           continue;
0390
0391         Basic2DVector<double> thc(p3.x(), p3.y());
0392
0393         auto curv_ = predictionRPhi.curvature(thc);
0394         double p2_r = point2.r();
0395         double p2_z = point2.z();  // they will be modified!
0396
0397         l2rzFixup(predictionRPhi, curv_, *doublets.hit(ip, HitDoublets::outer), p2_r, p2_z, tTopo);
0398         l3rzFixup(predictionRPhi, curv_, *hits.theHits[KDdata].hit(), p3_r, p3_z, tTopo);
0399
0400         Range rangeRZ;
0401         if (useBend) {
0402           HelixRZ updatedHelix(&predictionRPhi, gp1.z(), p2_z, curv_);
0403           rangeRZ = predRZ.helix1(barrelLayer ? p3_r : p3_z, updatedHelix);
0404         } else {
0405           float tIP = predictionRPhi.transverseIP(thc);
0406           PixelRecoPointRZ updatedPoint2(p2_r, p2_z);
0407           PixelRecoLineRZ updatedLine(line.origin(), point2, tIP);
0408           rangeRZ = predRZ.line(barrelLayer ? p3_r : p3_z, line);
0409         }
0410         correction.correctRZRange(rangeRZ);
0411
0412         double err = nSigmaRZ * hits.dv[KDdata];
0413
0414         rangeRZ.first -= err, rangeRZ.second += err;
0415
0416         if (!rangeRZ.inside(barrelLayer ? p3_z : p3_r))
0417           continue;
0418
0419         if (theMaxElement != 0 && result.size() >= theMaxElement) {
0420           result.clear();
0421           if (tripletLastLayerIndex)
0422             tripletLastLayerIndex->clear();
0423           edm::LogError("TooManyTriplets") << " number of triples exceed maximum. no triplets produced.";
0424           return;
0425         }
0426         result.emplace_back(
0427             doublets.hit(ip, HitDoublets::inner), doublets.hit(ip, HitDoublets::outer), hits.theHits[KDdata].hit());
0428         // to bookkeep the triplets and 3rd layers in triplet EDProducer
0429         if (tripletLastLayerIndex)
0430           tripletLastLayerIndex->push_back(il);
0431       }
0432     }
0433   }
0434   // std::cout << "found triplets " << result.size() << std::endl;
0435 }