RPCSimSimple.cc

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#include "Geometry/RPCGeometry/interface/RPCRoll.h"
#include "Geometry/RPCGeometry/interface/RPCRollSpecs.h"
#include "SimMuon/RPCDigitizer/src/RPCSimSimple.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"

#include <cstring>
#include <iostream>
#include <string>
#include <vector>
#include <cstdlib>
#include <utility>
#include <map>

RPCSimSimple::RPCSimSimple(const edm::ParameterSet& config) : RPCSim(config) {
  rate = config.getParameter<double>("Rate");
  nbxing = config.getParameter<int>("Nbxing");
  gate = config.getParameter<double>("Gate");

  _rpcSync = new RPCSynchronizer(config);
}

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

void RPCSimSimple::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);
    //    const LocalPoint& exit=_hit->exitPoint();

    std::pair<int, int> digi(topology.channel(entr) + 1, time_hit);

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

void RPCSimSimple::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);
  }
}