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);
  }

}