PreMixingSiStripWorker.cc

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#include "FWCore/Framework/interface/Event.h"
#include "FWCore/Framework/interface/ConsumesCollector.h"
#include "FWCore/Framework/interface/ProducerBase.h"
#include "FWCore/ParameterSet/interface/ParameterSet.h"
#include "FWCore/MessageLogger/interface/MessageLogger.h"
#include "FWCore/ServiceRegistry/interface/Service.h"
#include "DataFormats/Common/interface/Handle.h"
#include "SimGeneral/MixingModule/interface/PileUpEventPrincipal.h"
#include "CondFormats/SiStripObjects/interface/SiStripBadStrip.h"
#include "CalibTracker/Records/interface/SiStripDependentRecords.h"

#include "DataFormats/Common/interface/Handle.h"
#include "FWCore/Utilities/interface/RandomNumberGenerator.h"

//Data Formats
#include "DataFormats/Common/interface/DetSetVector.h"
#include "DataFormats/Common/interface/DetSet.h"
#include "DataFormats/SiStripDigi/interface/SiStripDigi.h"

#include "CondFormats/SiStripObjects/interface/SiStripNoises.h"
#include "CondFormats/SiStripObjects/interface/SiStripPedestals.h"
#include "CondFormats/SiStripObjects/interface/SiStripThreshold.h"
#include "CalibFormats/SiStripObjects/interface/SiStripGain.h"
#include "SimTracker/SiStripDigitizer/interface/SiTrivialDigitalConverter.h"
#include "SimTracker/SiStripDigitizer/interface/SiGaussianTailNoiseAdder.h"
#include "RecoLocalTracker/SiStripZeroSuppression/interface/SiStripFedZeroSuppression.h"

#include "Geometry/TrackerGeometryBuilder/interface/TrackerGeometry.h"
#include "Geometry/CommonDetUnit/interface/GeomDet.h"
#include "Geometry/TrackerGeometryBuilder/interface/StripGeomDetUnit.h"
#include "Geometry/CommonTopologies/interface/StripTopology.h"
#include "Geometry/CommonDetUnit/interface/GeomDetType.h"

#include "CLHEP/Random/RandFlat.h"

#include "SimGeneral/PreMixingModule/interface/PreMixingWorker.h"
#include "SimGeneral/PreMixingModule/interface/PreMixingWorkerFactory.h"

#include <map>
#include <memory>

class PreMixingSiStripWorker: public PreMixingWorker {
public:
  PreMixingSiStripWorker(const edm::ParameterSet& ps, edm::ProducerBase& producer, edm::ConsumesCollector && iC);
  ~PreMixingSiStripWorker() override = default;

  void initializeEvent(edm::Event const& e, edm::EventSetup const& c) override;
  void addSignals(edm::Event const& e, edm::EventSetup const& es) override;
  void addPileups(PileUpEventPrincipal const& pep, edm::EventSetup const& es) override;
  void put(edm::Event &e, edm::EventSetup const& iSetup, std::vector<PileupSummaryInfo> const& ps, int bs) override;

private:
  void DMinitializeDetUnit(StripGeomDetUnit const * det, const edm::EventSetup& iSetup );

  // data specifiers

  edm::InputTag SistripLabelSig_ ;        // name given to collection of SiStrip digis
  edm::InputTag SiStripPileInputTag_ ;    // InputTag for pileup strips
  std::string SiStripDigiCollectionDM_  ; // secondary name to be given to new SiStrip digis

  edm::InputTag SistripAPVLabelSig_;      // where to find vector of dead APVs
  edm::InputTag SiStripAPVPileInputTag_;
  std::string SistripAPVListDM_;          // output tag


  // 

  typedef float Amplitude;
  typedef std::pair<uint16_t, Amplitude> RawDigi;  // Replacement for SiStripDigi with pulse height instead of integer ADC
  typedef std::vector<SiStripDigi> OneDetectorMap;   // maps by strip ID for later combination - can have duplicate strips
  typedef std::vector<RawDigi> OneDetectorRawMap;   // maps by strip ID for later combination - can have duplicate strips
  typedef std::map<uint32_t, OneDetectorMap> SiGlobalIndex; // map to all data for each detector ID
  typedef std::map<uint32_t, OneDetectorRawMap> SiGlobalRawIndex; // map to all data for each detector ID

  typedef SiDigitalConverter::DigitalVecType DigitalVecType;

  SiGlobalIndex SiHitStorage_;
  SiGlobalRawIndex SiRawDigis_;

  // variables for temporary storage of mixed hits:
  typedef std::map<int, Amplitude>  SignalMapType;
  typedef std::map<uint32_t, SignalMapType>  signalMaps;

  const SignalMapType* getSignal(uint32_t detID) const {
    auto where = signals_.find(detID);
    if(where == signals_.end()) {
      return nullptr;
    }
    return &where->second;
  }

  signalMaps signals_;

  // to keep track of dead APVs from HIP interactions
  typedef std::multimap< uint32_t, std::bitset<6> > APVMap;

  APVMap theAffectedAPVmap_;

  // for noise adding:

  std::string gainLabel;
  bool SingleStripNoise;
  bool peakMode;
  double theThreshold;
  double theElectronPerADC;
  bool APVSaturationFromHIP_;
  int theFedAlgo;
  std::string geometryType;

  std::unique_ptr<SiGaussianTailNoiseAdder> theSiNoiseAdder;
  std::unique_ptr<SiStripFedZeroSuppression> theSiZeroSuppress;
  std::unique_ptr<SiTrivialDigitalConverter> theSiDigitalConverter;

  edm::ESHandle<TrackerGeometry> pDD;

  // bad channels for each detector ID
  std::map<unsigned int, std::vector<bool> > allBadChannels;
  // channels killed by HIP interactions for each detector ID
  std::map<unsigned int, std::vector<bool> > allHIPChannels;
  // first and last channel wit signal for each detector ID
  std::map<unsigned int, size_t> firstChannelsWithSignal;
  std::map<unsigned int, size_t> lastChannelsWithSignal;

  //----------------------------

  class StrictWeakOrdering{
  public:
    bool operator() (SiStripDigi i,SiStripDigi j) const {return i.strip() < j.strip();}
  };

  class StrictWeakRawOrdering{
  public:
    bool operator() (RawDigi i,RawDigi j) const {return i.first < j.first;}
  };

};

PreMixingSiStripWorker::PreMixingSiStripWorker(const edm::ParameterSet& ps, edm::ProducerBase& producer, edm::ConsumesCollector && iC): 
  gainLabel(ps.getParameter<std::string>("Gain")),
  SingleStripNoise(ps.getParameter<bool>("SingleStripNoise")),
  peakMode(ps.getParameter<bool>("APVpeakmode")),
  theThreshold(ps.getParameter<double>("NoiseSigmaThreshold")),
  theElectronPerADC(ps.getParameter<double>( peakMode ? "electronPerAdcPeak" : "electronPerAdcDec" )),
  APVSaturationFromHIP_(ps.getParameter<bool>("APVSaturationFromHIP")),
  theFedAlgo(ps.getParameter<int>("FedAlgorithm_PM")),
  geometryType(ps.getParameter<std::string>("GeometryType")),
  theSiZeroSuppress(new SiStripFedZeroSuppression(theFedAlgo)),
  theSiDigitalConverter(new SiTrivialDigitalConverter(theElectronPerADC, false)) // no premixing

{                                                         
  // declare the products to produce

  SistripLabelSig_   = ps.getParameter<edm::InputTag>("SistripLabelSig");
  SiStripPileInputTag_ = ps.getParameter<edm::InputTag>("SiStripPileInputTag");

  SiStripDigiCollectionDM_  = ps.getParameter<std::string>("SiStripDigiCollectionDM");
  SistripAPVListDM_= ps.getParameter<std::string>("SiStripAPVListDM");

  producer.produces< edm::DetSetVector<SiStripDigi> > (SiStripDigiCollectionDM_);

  if(APVSaturationFromHIP_) { 
    SistripAPVLabelSig_ = ps.getParameter<edm::InputTag>("SistripAPVLabelSig");
    SiStripAPVPileInputTag_ = ps.getParameter<edm::InputTag>("SistripAPVPileInputTag");
    iC.consumes< std::vector<std::pair<int,std::bitset<6>> > >(SistripAPVLabelSig_);
  }
  iC.consumes<edm::DetSetVector<SiStripDigi>>(SistripLabelSig_);
  // clear local storage for this event                                                                     
  SiHitStorage_.clear();

  edm::Service<edm::RandomNumberGenerator> rng;
  if ( ! rng.isAvailable()) {
    throw cms::Exception("Psiguration")
      << "SiStripDigitizer requires the RandomNumberGeneratorService\n"
      "which is not present in the psiguration file.  You must add the service\n"
      "in the configuration file or remove the modules that require it.";
  }
  
  theSiNoiseAdder.reset(new SiGaussianTailNoiseAdder(theThreshold));
}
           
void PreMixingSiStripWorker::initializeEvent(const edm::Event &e, edm::EventSetup const& iSetup) {
  // initialize individual detectors so we can copy real digitization code:

  iSetup.get<TrackerDigiGeometryRecord>().get(geometryType,pDD);

  for(auto iu = pDD->detUnits().begin(); iu != pDD->detUnits().end(); ++iu) {
    unsigned int detId = (*iu)->geographicalId().rawId();
    DetId idet=DetId(detId);
    unsigned int isub=idet.subdetId();
    if((isub == StripSubdetector::TIB) ||
       (isub == StripSubdetector::TID) ||
       (isub == StripSubdetector::TOB) ||
       (isub == StripSubdetector::TEC)) {

      auto stripdet = dynamic_cast<StripGeomDetUnit const*>((*iu));
      assert(stripdet != nullptr);
      DMinitializeDetUnit(stripdet, iSetup);
    }
  }
}


void PreMixingSiStripWorker::DMinitializeDetUnit(StripGeomDetUnit const * det, const edm::EventSetup& iSetup ) { 

  edm::ESHandle<SiStripBadStrip> deadChannelHandle;
  iSetup.get<SiStripBadChannelRcd>().get(deadChannelHandle);

  unsigned int detId = det->geographicalId().rawId();
  int numStrips = (det->specificTopology()).nstrips();  

  SiStripBadStrip::Range detBadStripRange = deadChannelHandle->getRange(detId);
  //storing the bad strip of the the module. the module is not removed but just signal put to 0
  std::vector<bool>& badChannels = allBadChannels[detId];
  std::vector<bool>& hipChannels = allHIPChannels[detId];
  badChannels.clear();
  badChannels.insert(badChannels.begin(), numStrips, false);
  hipChannels.clear();
  hipChannels.insert(hipChannels.begin(), numStrips, false);

  for(SiStripBadStrip::ContainerIterator it = detBadStripRange.first; it != detBadStripRange.second; ++it) {
    SiStripBadStrip::data fs = deadChannelHandle->decode(*it);
    for(int strip = fs.firstStrip; strip < fs.firstStrip + fs.range; ++strip) badChannels[strip] = true;
  }
  firstChannelsWithSignal[detId] = numStrips;
  lastChannelsWithSignal[detId]= 0;
}


void PreMixingSiStripWorker::addSignals(const edm::Event &e, edm::EventSetup const& es) { 
  // fill in maps of hits

  edm::Handle< edm::DetSetVector<SiStripDigi> >  input;

  if( e.getByLabel(SistripLabelSig_,input) ) {
    OneDetectorMap LocalMap;

    //loop on all detsets (detectorIDs) inside the input collection
    edm::DetSetVector<SiStripDigi>::const_iterator DSViter=input->begin();
    for (; DSViter!=input->end();DSViter++){

#ifdef DEBUG
      LogDebug("PreMixingSiStripWorker")  << "Processing DetID " << DSViter->id;
#endif

      LocalMap.clear();
      LocalMap.reserve((DSViter->data).size());
      LocalMap.insert(LocalMap.end(),(DSViter->data).begin(),(DSViter->data).end());    
    
      SiHitStorage_.insert( SiGlobalIndex::value_type( DSViter->id, LocalMap ) );
    }
 
  }

  // keep here for future reference.  In current implementation, HIP killing is done once in PU file
  /*  if(APVSaturationFromHIP_) {
      edm::Handle<std::vector<std::pair<int,std::bitset<6>> > >  APVinput;

      if( e.getByLabel(SistripAPVLabelSig_,APVinput) ) {

      std::vector<std::pair<int,std::bitset<6>> >::const_iterator entry = APVinput->begin();
      for( ; entry != APVinput->end(); entry++) {
      theAffectedAPVmap_.insert(APVMap::value_type(entry->first, entry->second));
      }
      }
      } */

} // end of addSiStripSignals



void PreMixingSiStripWorker::addPileups(PileUpEventPrincipal const& pep, edm::EventSetup const& es) {
  LogDebug("PreMixingSiStripWorker") <<"\n===============> adding pileups from event  "<<pep.principal().id()<<" for bunchcrossing "<<pep.bunchCrossing();

  // fill in maps of hits; same code as addSignals, except now applied to the pileup events

  edm::Handle<edm::DetSetVector<SiStripDigi>> inputHandle;
  pep.getByLabel(SiStripPileInputTag_, inputHandle);

  if(inputHandle.isValid()) {
    const auto& input = *inputHandle;

    OneDetectorMap LocalMap;

    //loop on all detsets (detectorIDs) inside the input collection
    edm::DetSetVector<SiStripDigi>::const_iterator DSViter=input.begin();
    for (; DSViter!=input.end();DSViter++){

#ifdef DEBUG
      LogDebug("PreMixingSiStripWorker")  << "Pileups: Processing DetID " << DSViter->id;
#endif

      // find correct local map (or new one) for this detector ID

      SiGlobalIndex::const_iterator itest;

      itest = SiHitStorage_.find(DSViter->id);

      if(itest!=SiHitStorage_.end()) {  // this detID already has hits, add to existing map

        LocalMap = itest->second;

        // fill in local map with extra channels
        LocalMap.insert(LocalMap.end(),(DSViter->data).begin(),(DSViter->data).end());
        std::stable_sort(LocalMap.begin(),LocalMap.end(),PreMixingSiStripWorker::StrictWeakOrdering());
        SiHitStorage_[DSViter->id]=LocalMap;
      
      }
      else{ // fill local storage with this information, put in global collection

        LocalMap.clear();
        LocalMap.reserve((DSViter->data).size());
        LocalMap.insert(LocalMap.end(),(DSViter->data).begin(),(DSViter->data).end());

        SiHitStorage_.insert( SiGlobalIndex::value_type( DSViter->id, LocalMap ) );
      }
    }

    if(APVSaturationFromHIP_) {
      edm::Handle<std::vector<std::pair<int,std::bitset<6>>>> inputAPVHandle;
      pep.getByLabel(SiStripAPVPileInputTag_, inputAPVHandle);

      if(inputAPVHandle.isValid()) {

        const auto &APVinput = inputAPVHandle;

        std::vector<std::pair<int,std::bitset<6>> >::const_iterator entry = APVinput->begin();
        for( ; entry != APVinput->end(); entry++) {
          theAffectedAPVmap_.insert( APVMap::value_type(entry->first, entry->second ));
        }
      }
    }
  }
}


 
void PreMixingSiStripWorker::put(edm::Event &e, edm::EventSetup const& iSetup, std::vector<PileupSummaryInfo> const& ps, int bs) {

  // set up machinery to do proper noise adding:
  edm::ESHandle<SiStripGain> gainHandle;
  edm::ESHandle<SiStripNoises> noiseHandle;
  edm::ESHandle<SiStripThreshold> thresholdHandle;
  edm::ESHandle<SiStripPedestals> pedestalHandle;
  edm::ESHandle<SiStripBadStrip> deadChannelHandle;
  iSetup.get<SiStripGainSimRcd>().get(gainLabel,gainHandle);
  iSetup.get<SiStripNoisesRcd>().get(noiseHandle);
  iSetup.get<SiStripThresholdRcd>().get(thresholdHandle);
  iSetup.get<SiStripPedestalsRcd>().get(pedestalHandle);

  edm::Service<edm::RandomNumberGenerator> rng;
  CLHEP::HepRandomEngine* engine = &rng->getEngine(e.streamID());

  std::map< int,std::bitset<6>>  DeadAPVList;
  DeadAPVList.clear();


  // First, have to convert all ADC counts to raw pulse heights so that values can be added properly
  // In PreMixing, pulse heights are saved with ADC = sqrt(9.0*PulseHeight) - have to undo. 

  // This is done here because it's the only place we have access to EventSetup 
  // Simultaneously, merge lists of hit channels in each DetId.                
  // Signal Digis are in the list first, have to merge lists of hit strips on the fly,
  // add signals on duplicates later                                                       

  OneDetectorRawMap LocalRawMap;

  // Now, loop over hits and add them to the map in the proper sorted order        
  // Note: We are assuming that the hits from the Signal events have been created in
  // "PreMix" mode, rather than in the standard ADC conversion routines.  If not, this
  // doesn't work at all.

  // At the moment, both Signal and Reconstituted PU hits have the same compression algorithm.
  // If this were different, and one needed gains, the conversion back to pulse height can only
  // be done in this routine.  So, yes, there is an extra loop over hits here in the current code,
  // because, in principle, one could convert to pulse height during the read/store phase.    

  for(SiGlobalIndex::const_iterator IDet = SiHitStorage_.begin();
      IDet != SiHitStorage_.end(); IDet++) {

    uint32_t detID = IDet->first;

    OneDetectorMap LocalMap = IDet->second;

    //loop over hit strips for this DetId, do conversion to pulse height, store.

    LocalRawMap.clear();

    OneDetectorMap::const_iterator iLocal  = LocalMap.begin();
    for(;iLocal != LocalMap.end(); ++iLocal) {

      uint16_t currentStrip = iLocal->strip();
      float signal = float(iLocal->adc());
      if(iLocal->adc() == 1022) signal = 1500.;  // average values for overflows
      if(iLocal->adc() == 1023) signal = 3000.;

      //convert signals back to raw counts 

      float ReSignal = signal*signal/9.0;  // The PreMixing conversion is adc = sqrt(9.0*pulseHeight)

      RawDigi NewRawDigi = std::make_pair(currentStrip,ReSignal);

      LocalRawMap.push_back(NewRawDigi);

    }

    // save information for this detiD into global map
    SiRawDigis_.insert( SiGlobalRawIndex::value_type( detID, LocalRawMap ) );
  }

  // If we are killing APVs, merge list of dead ones before we digitize

  int NumberOfBxBetweenHIPandEvent=1e3;

  if(APVSaturationFromHIP_) { 

    // calculate affected BX parameter

    bool HasAtleastOneAffectedAPV=false;
    while(!HasAtleastOneAffectedAPV){
      for(int bx=floor(300.0/25.0);bx>0;bx--){ //Reminder: make these numbers not hard coded!!
        float temp=CLHEP::RandFlat::shoot(engine)<0.5?1:0;
        if(temp==1 && bx<NumberOfBxBetweenHIPandEvent){
          NumberOfBxBetweenHIPandEvent=bx;
          HasAtleastOneAffectedAPV=true;
        }
      }
    }

    APVMap::const_iterator iAPVchk;
    uint32_t formerID = 0;
    uint32_t currentID;
    std::bitset<6> NewAPVBits;

    for(APVMap::const_iterator iAPV  = theAffectedAPVmap_.begin();
        iAPV != theAffectedAPVmap_.end(); ++iAPV) {

      currentID = iAPV->first;

      if (currentID == formerID) { // we have to OR these
        for( int ibit=0; ibit<6; ++ibit){
          NewAPVBits[ibit] = NewAPVBits[ibit]||(iAPV->second)[ibit];
        }
      }
      else {
        DeadAPVList[currentID]=NewAPVBits;          
        //save pointers for next iteration                                 
        formerID = currentID;
        NewAPVBits = iAPV->second;
      }

      iAPVchk = iAPV;
      if((++iAPVchk) == theAffectedAPVmap_.end()) {  //make sure not to lose the last one 
        DeadAPVList[currentID]=NewAPVBits;          
      }
    }

  }
  // 

  //  Ok, done with merging raw signals and APVs - now add signals on duplicate strips 

  // collection of Digis to put in the event
  std::vector< edm::DetSet<SiStripDigi> > vSiStripDigi;

  // loop through our collection of detectors, merging hits and making a new list of "signal" digis

  // clear some temporary storage for later digitization:

  signals_.clear();

  // big loop over Detector IDs:
  for(SiGlobalRawIndex::const_iterator IDet = SiRawDigis_.begin();
      IDet != SiRawDigis_.end(); IDet++) {

    uint32_t detID = IDet->first;

    SignalMapType Signals;
    Signals.clear();

    OneDetectorRawMap LocalMap = IDet->second;

    //counter variables
    int formerStrip = -1;
    int currentStrip;
    float ADCSum = 0;

    //loop over hit strips for this DetId, add duplicates 

    OneDetectorRawMap::const_iterator iLocalchk;
    OneDetectorRawMap::const_iterator iLocal  = LocalMap.begin();
    for(;iLocal != LocalMap.end(); ++iLocal) {

      currentStrip = iLocal->first;  // strip is first element 

      if (currentStrip == formerStrip) { // we have to add these digis together 

        ADCSum+=iLocal->second ;          // raw pulse height is second element. 
      }
      else{
        if(formerStrip!=-1){
          Signals.insert( std::make_pair(formerStrip, ADCSum));
        }
        // save pointers for next iteration 
        formerStrip = currentStrip;
        ADCSum = iLocal->second; // lone ADC  
      }

      iLocalchk = iLocal;
      if((++iLocalchk) == LocalMap.end()) {  //make sure not to lose the last one  
        Signals.insert( std::make_pair(formerStrip, ADCSum));
      }
    }
    // save merged map: 
    signals_.insert( std::make_pair( detID, Signals));
  }

  //Now, do noise, zero suppression, take into account bad channels, etc.
  // This section stolen from SiStripDigitizerAlgorithm
  // must loop over all detIds in the tracker to get all of the noise added properly.
  for( const auto& iu : pDD->detUnits()) {

    const StripGeomDetUnit* sgd = dynamic_cast<const StripGeomDetUnit*>(iu);
    if (sgd != nullptr){

      uint32_t detID = sgd->geographicalId().rawId();

      edm::DetSet<SiStripDigi> SSD(detID); // Make empty collection with this detector ID

      int numStrips = (sgd->specificTopology()).nstrips();

      // see if there is some signal on this detector

      const SignalMapType* theSignal(getSignal(detID));

      std::vector<float> detAmpl(numStrips, 0.);
      if(theSignal) {
        for(const auto& amp : *theSignal) {
          detAmpl[amp.first] = amp.second;
        }
      }

      //removing signal from the dead (and HIP effected) strips
      std::vector<bool>& badChannels = allBadChannels[detID];

      for(int strip =0; strip < numStrips; ++strip) {
        if(badChannels[strip]) detAmpl[strip] = 0.;
      }
         
      if(APVSaturationFromHIP_) {
        std::bitset<6> & bs=DeadAPVList[detID];

        if(bs.any()){
          // Here below is the scaling function which describes the evolution of the baseline (i.e. how the charge is suppressed).
          // This must be replaced as soon as we have a proper modeling of the baseline evolution from VR runs
          float Shift=1-NumberOfBxBetweenHIPandEvent/floor(300.0/25.0); //Reminder: make these numbers not hardcoded!! 
          float randomX=CLHEP::RandFlat::shoot(engine);
          float scalingValue=(randomX-Shift)*10.0/7.0-3.0/7.0;

          for(int strip =0; strip < numStrips; ++strip) {
            if(!badChannels[strip] &&  bs[strip/128]==1){
              detAmpl[strip] *=scalingValue>0?scalingValue:0.0;
            }
          }
        }
      }

      SiStripNoises::Range detNoiseRange = noiseHandle->getRange(detID);
      SiStripApvGain::Range detGainRange = gainHandle->getRange(detID);

      // Gain conversion is already done during signal adding
      //convert our signals back to raw counts so that we can add noise properly:

      /*
        if(theSignal) {
        for(unsigned int iv = 0; iv!=detAmpl.size(); iv++) {
        float signal = detAmpl[iv];
        if(signal > 0) {
        float gainValue = gainHandle->getStripGain(iv, detGainRange);
        signal *= theElectronPerADC/gainValue;
        detAmpl[iv] = signal;
        }
        }
        }
      */
    
      //SiStripPedestals::Range detPedestalRange = pedestalHandle->getRange(detID);

      // -----------------------------------------------------------

      size_t firstChannelWithSignal = 0;
      size_t lastChannelWithSignal = numStrips;

      if(SingleStripNoise){
        std::vector<float> noiseRMSv;
        noiseRMSv.clear();
        noiseRMSv.insert(noiseRMSv.begin(),numStrips,0.);
        for(int strip=0; strip< numStrips; ++strip){
          if(!badChannels[strip]){
            float gainValue = gainHandle->getStripGain(strip, detGainRange);
            noiseRMSv[strip] = (noiseHandle->getNoise(strip,detNoiseRange))* theElectronPerADC/gainValue;
          }
        }
        theSiNoiseAdder->addNoiseVR(detAmpl, noiseRMSv, engine);
      } else {
        int RefStrip = int(numStrips/2.);
        while(RefStrip<numStrips&&badChannels[RefStrip]){ //if the refstrip is bad, I move up to when I don't find it                                            
          RefStrip++;
        }
        if(RefStrip<numStrips){
          float RefgainValue = gainHandle->getStripGain(RefStrip, detGainRange);
          float RefnoiseRMS = noiseHandle->getNoise(RefStrip,detNoiseRange) *theElectronPerADC/RefgainValue;

          theSiNoiseAdder->addNoise(detAmpl,firstChannelWithSignal,lastChannelWithSignal,numStrips,RefnoiseRMS, engine);
        }
      }
    
      DigitalVecType digis;
      theSiZeroSuppress->suppress(theSiDigitalConverter->convert(detAmpl, gainHandle, detID), digis, detID,noiseHandle,thresholdHandle);


      SSD.data = digis;

      // stick this into the global vector of detector info
      vSiStripDigi.push_back(SSD);
    
    } // end of loop over one detector

  } // end of big loop over all detector IDs

    // put the collection of digis in the event   
  edm::LogInfo("PreMixingSiStripWorker") << "total # Merged strips: " << vSiStripDigi.size() ;

  // make new digi collection
    
  std::unique_ptr< edm::DetSetVector<SiStripDigi> > MySiStripDigis(new edm::DetSetVector<SiStripDigi>(vSiStripDigi) );

  // put collection

  e.put(std::move(MySiStripDigis), SiStripDigiCollectionDM_ );

  // clear local storage for this event
  SiHitStorage_.clear();
  SiRawDigis_.clear();
  signals_.clear();
}

DEFINE_PREMIXING_WORKER(PreMixingSiStripWorker);