RPCSimParam.cc

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#include "Geometry/RPCGeometry/interface/RPCRoll.h"
#include "Geometry/RPCGeometry/interface/RPCRollSpecs.h"
#include "SimMuon/RPCDigitizer/src/RPCSimParam.h"
#include "Geometry/CommonTopologies/interface/RectangularStripTopology.h"
#include "Geometry/CommonTopologies/interface/TrapezoidalStripTopology.h"

#include <cmath>

#include "CLHEP/Random/RandFlat.h"
#include "CLHEP/Random/RandPoissonQ.h"

RPCSimParam::RPCSimParam(const edm::ParameterSet& config) : RPCSim(config) {
  aveEff = config.getParameter<double>("averageEfficiency");
  aveCls = config.getParameter<double>("averageClusterSize");
  resRPC = config.getParameter<double>("timeResolution");
  timOff = config.getParameter<double>("timingRPCOffset");
  dtimCs = config.getParameter<double>("deltatimeAdjacentStrip");
  resEle = config.getParameter<double>("timeJitter");
  sspeed = config.getParameter<double>("signalPropagationSpeed");
  lbGate = config.getParameter<double>("linkGateWidth");
  rpcdigiprint = config.getParameter<bool>("printOutDigitizer");

  rate = config.getParameter<double>("Rate");
  nbxing = config.getParameter<int>("Nbxing");
  gate = config.getParameter<double>("Gate");

  if (rpcdigiprint) {
    std::cout << "Average Efficiency        = " << aveEff << std::endl;
    std::cout << "Average Cluster Size      = " << aveCls << " strips" << std::endl;
    std::cout << "RPC Time Resolution       = " << resRPC << " ns" << std::endl;
    std::cout << "RPC Signal formation time = " << timOff << " ns" << std::endl;
    std::cout << "RPC adjacent strip delay  = " << dtimCs << " ns" << std::endl;
    std::cout << "Electronic Jitter         = " << resEle << " ns" << std::endl;
    std::cout << "Signal propagation time   = " << sspeed << " x c" << std::endl;
    std::cout << "Link Board Gate Width     = " << lbGate << " ns" << std::endl;
  }

  _rpcSync = new RPCSynchronizer(config);
}

RPCSimParam::~RPCSimParam() { delete _rpcSync; }

void RPCSimParam::simulate(const RPCRoll* roll, const edm::PSimHitContainer& rpcHits, CLHEP::HepRandomEngine* engine) {
  _rpcSync->setRPCSimSetUp(getRPCSimSetUp());
  theRpcDigiSimLinks.clear();
  theDetectorHitMap.clear();
  theRpcDigiSimLinks = RPCDigiSimLinks(roll->id().rawId());

  const Topology& topology = roll->specs()->topology();

  for (edm::PSimHitContainer::const_iterator _hit = rpcHits.begin(); _hit != rpcHits.end(); ++_hit) {
    // Here I hould check if the RPC are up side down;
    const LocalPoint& entr = _hit->entryPoint();
    int time_hit = _rpcSync->getSimHitBx(&(*_hit), engine);

    // Effinciecy
    float eff = CLHEP::RandFlat::shoot(engine);
    if (eff < aveEff) {
      int centralStrip = topology.channel(entr) + 1;
      int fstrip = centralStrip;
      int lstrip = centralStrip;
      // Compute the cluster size
      double w = CLHEP::RandFlat::shoot(engine);
      if (w < 1.e-10)
        w = 1.e-10;
      int clsize = static_cast<int>(-1. * aveCls * log(w) + 1.);
      std::vector<int> cls;
      cls.push_back(centralStrip);
      if (clsize > 1) {
        for (int cl = 0; cl < (clsize - 1) / 2; cl++)
          if (centralStrip - cl - 1 >= 1) {
            fstrip = centralStrip - cl - 1;
            cls.push_back(fstrip);
          }
        for (int cl = 0; cl < (clsize - 1) / 2; cl++)
          if (centralStrip + cl + 1 <= roll->nstrips()) {
            lstrip = centralStrip + cl + 1;
            cls.push_back(lstrip);
          }
        if (clsize % 2 == 0) {
          // insert the last strip according to the
          // simhit position in the central strip
          double deltaw = roll->centreOfStrip(centralStrip).x() - entr.x();
          if (deltaw < 0.) {
            if (lstrip < roll->nstrips()) {
              lstrip++;
              cls.push_back(lstrip);
            }
          } else {
            if (fstrip > 1) {
              fstrip--;
              cls.push_back(fstrip);
            }
          }
        }
      }

      for (std::vector<int>::iterator i = cls.begin(); i != cls.end(); i++) {
        // Check the timing of the adjacent strip
        std::pair<unsigned int, int> digi(*i, time_hit);

        theDetectorHitMap.insert(DetectorHitMap::value_type(digi, &(*_hit)));
        strips.insert(digi);
      }
    }
  }
}

void RPCSimParam::simulateNoise(const RPCRoll* roll, CLHEP::HepRandomEngine* engine) {
  RPCDetId rpcId = roll->id();
  int nstrips = roll->nstrips();
  double area = 0.0;

  if (rpcId.region() == 0) {
    const RectangularStripTopology* top_ = dynamic_cast<const RectangularStripTopology*>(&(roll->topology()));
    float xmin = (top_->localPosition(0.)).x();
    float xmax = (top_->localPosition((float)roll->nstrips())).x();
    float striplength = (top_->stripLength());
    area = striplength * (xmax - xmin);
  } else {
    const TrapezoidalStripTopology* top_ = dynamic_cast<const TrapezoidalStripTopology*>(&(roll->topology()));
    float xmin = (top_->localPosition(0.)).x();
    float xmax = (top_->localPosition((float)roll->nstrips())).x();
    float striplength = (top_->stripLength());
    area = striplength * (xmax - xmin);
  }

  double ave = rate * nbxing * gate * area * 1.0e-9;

  CLHEP::RandPoissonQ randPoissonQ(*engine, ave);
  N_hits = randPoissonQ.fire();

  for (int i = 0; i < N_hits; i++) {
    int strip = static_cast<int>(CLHEP::RandFlat::shoot(engine, 1, nstrips));
    int time_hit;
    time_hit = (static_cast<int>(CLHEP::RandFlat::shoot(engine, (nbxing * gate) / gate))) - nbxing / 2;
    std::pair<int, int> digi(strip, time_hit);
    strips.insert(digi);
  }
}