CORSIKAGen_module.cc

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#ifndef EVGEN_CORSIKAGen_H
#define EVGEN_CORSIKAGen_H

// ROOT includes
#include "TRandom3.h"
#include "TDatabasePDG.h"
#include "TString.h"
#include "TSystem.h" //need BaseName and DirName

// Framework includes
#include "art/Framework/Core/EDProducer.h"
#include "art/Framework/Core/ModuleMacros.h"
#include "art/Framework/Principal/Event.h"
#include "fhiclcpp/ParameterSet.h"
#include "art/Framework/Principal/Handle.h"
#include "art/Framework/Core/ModuleMacros.h"
#include "art/Framework/Services/Registry/ServiceHandle.h"
#include "art/Framework/Services/Optional/TFileService.h"
#include "art/Framework/Services/Optional/TFileDirectory.h"
#include "messagefacility/MessageLogger/MessageLogger.h"
#include "art/Framework/Services/Optional/RandomNumberGenerator.h"

// art extensions
#include "nutools/RandomUtils/NuRandomService.h"

// larsoft includes
#include "nusimdata/SimulationBase/MCTruth.h"
#include "nusimdata/SimulationBase/MCParticle.h"
#include "nutools/EventGeneratorBase/evgenbase.h"
#include "larcorealg/Geometry/geo.h"
#include "larcore/Geometry/Geometry.h"
#include "larcorealg/Geometry/CryostatGeo.h"
#include "larcoreobj/SummaryData/RunData.h"

#include <sqlite3.h> 
#include "CLHEP/Random/RandFlat.h"
#include "CLHEP/Random/RandPoissonQ.h"
#include "ifdh.h"  //to handle flux files

namespace evgen {

  class CORSIKAGen : public art::EDProducer {
  public:
    explicit CORSIKAGen(fhicl::ParameterSet const& pset);
    virtual ~CORSIKAGen();                       
    
    void produce(art::Event& evt);  
    void beginJob();
    void beginRun(art::Run& run);
    void reconfigure(fhicl::ParameterSet const& p);

   
  private:
    void openDBs();
    void populateNShowers();
    void populateTOffset();
    void GetSample(simb::MCTruth&);
    double wrapvar( const double var, const double low, const double high);
    double wrapvarBoxNo( const double var, const double low, const double high, int& boxno);
    void ProjectToBoxEdge(const double  xyz[],
                                        const double    dxyz[],
                                        const double xlo,
                                        const double xhi,
                                        const double ylo,
                                        const double yhi,
                                        const double zlo,
                                        const double zhi,
                                        double xyzout[]);
    
    int fShowerInputs=0; 
    std::vector<double> fNShowersPerEvent; 
    std::vector<int> fMaxShowers; //< Max number of showers to query, one per showerinput
    double fShowerBounds[6]={0.,0.,0.,0.,0.,0.}; 
    double fToffset_corsika=0.; 
    ifdh_ns::ifdh* fIFDH=0; 
    
    //fcl parameters
    double fProjectToHeight=0.; 
    std::vector< std::string > fShowerInputFiles; 
    std::vector< double > fShowerFluxConstants; 
    double fSampleTime=0.; 
    double fToffset=0.; 
    std::vector<double> fBuffBox; 
    double fShowerAreaExtension=0.; 
    sqlite3* fdb[5]; 
    double fRandomXZShift=0.; 
  };
}

namespace evgen{

  CORSIKAGen::CORSIKAGen(fhicl::ParameterSet const& p)
    : fProjectToHeight(p.get< double >("ProjectToHeight",0.)),
      fShowerInputFiles(p.get< std::vector< std::string > >("ShowerInputFiles")),
      fShowerFluxConstants(p.get< std::vector< double > >("ShowerFluxConstants")),
      fSampleTime(p.get< double >("SampleTime",0.)),
      fToffset(p.get< double >("TimeOffset",0.)),
      fBuffBox(p.get< std::vector< double > >("BufferBox",{0.0, 0.0, 0.0, 0.0, 0.0, 0.0})),
      fShowerAreaExtension(p.get< double >("ShowerAreaExtension",0.)),
      fRandomXZShift(p.get< double >("RandomXZShift",0.))
  {
    
    if(fShowerInputFiles.size() != fShowerFluxConstants.size() || fShowerInputFiles.size()==0 || fShowerFluxConstants.size()==0)
      throw cet::exception("CORSIKAGen") << "ShowerInputFiles and ShowerFluxConstants have different or invalid sizes!"<<"\n";
    fShowerInputs=fShowerInputFiles.size();
    
    if(fSampleTime==0.) throw cet::exception("CORSIKAGen") << "SampleTime not set!";
    
    if(fProjectToHeight==0.) mf::LogInfo("CORSIKAGen")<<"Using 0. for fProjectToHeight!"
    ;
    // create a default random engine; obtain the random seed from NuRandomService,
    // unless overridden in configuration with key "Seed"
    art::ServiceHandle<rndm::NuRandomService>()->createEngine(*this, "HepJamesRandom", "gen", p, { "Seed", "SeedGenerator" });
    art::ServiceHandle<rndm::NuRandomService>()->createEngine(*this, "HepJamesRandom", "pois", p, "SeedPoisson");

    this->reconfigure(p);
    
    this->openDBs();
    this->populateNShowers();
    this->populateTOffset();
    
    produces< std::vector<simb::MCTruth> >();
    produces< sumdata::RunData, art::InRun >();
    
  }
  
  CORSIKAGen::~CORSIKAGen(){
    for(int i=0; i<fShowerInputs; i++){
      sqlite3_close(fdb[i]);
    }
    //cleanup temp files
    fIFDH->cleanup();
  }
  
  void CORSIKAGen::ProjectToBoxEdge(    const double    xyz[],
                                        const double    indxyz[],
                                        const double    xlo,
                                        const double    xhi,
                                        const double    ylo,
                                        const double    yhi,
                                        const double    zlo,
                                        const double    zhi,
                                        double xyzout[]  ){
                                        
    
    //we want to project backwards, so take mirror of momentum
    const double dxyz[3]={-indxyz[0],-indxyz[1],-indxyz[2]};
      
    // Compute the distances to the x/y/z walls
    double dx = 99.E99;
    double dy = 99.E99;
    double dz = 99.E99;
    if      (dxyz[0] > 0.0) { dx = (xhi-xyz[0])/dxyz[0]; }
    else if (dxyz[0] < 0.0) { dx = (xlo-xyz[0])/dxyz[0]; }
    if      (dxyz[1] > 0.0) { dy = (yhi-xyz[1])/dxyz[1]; }
    else if (dxyz[1] < 0.0) { dy = (ylo-xyz[1])/dxyz[1]; }
    if      (dxyz[2] > 0.0) { dz = (zhi-xyz[2])/dxyz[2]; }
    else if (dxyz[2] < 0.0) { dz = (zlo-xyz[2])/dxyz[2]; }
    
    
    // Choose the shortest distance
    double d = 0.0;
    if      (dx < dy && dx < dz) d = dx;
    else if (dy < dz && dy < dx) d = dy;
    else if (dz < dx && dz < dy) d = dz;
    
    // Make the step
    for (int i = 0; i < 3; ++i) {
      xyzout[i] = xyz[i] + dxyz[i]*d;
    }
    
  }
  
  void CORSIKAGen::openDBs(){
    //choose files based on fShowerInputFiles, copy them with ifdh, open them
    // for c2: statement is unused
    //sqlite3_stmt *statement;
    //get rng engine
    art::ServiceHandle<art::RandomNumberGenerator> rng;
    CLHEP::HepRandomEngine &engine = rng->getEngine("gen");
    CLHEP::RandFlat flat(engine);
    
    //setup ifdh object
    if ( ! fIFDH ) fIFDH = new ifdh_ns::ifdh;
    const char* ifdh_debug_env = std::getenv("IFDH_DEBUG_LEVEL");
    if ( ifdh_debug_env ) {
      mf::LogInfo("CORSIKAGen") << "IFDH_DEBUG_LEVEL: " << ifdh_debug_env<<"\n";
      fIFDH->set_debug(ifdh_debug_env);
    }
    
    //get ifdh path for each file in fShowerInputFiles, put into selectedflist
    //if 1 file returned, use that file
    //if >1 file returned, randomly select one file
    //if 0 returned, make exeption for missing files
    std::vector<std::pair<std::string,long>> selectedflist;
    for(int i=0; i<fShowerInputs; i++){
      if(fShowerInputFiles[i].find("*")==std::string::npos){ 
        //if there are no wildcards, don't call findMatchingFiles
        selectedflist.push_back(std::make_pair(fShowerInputFiles[i],0));
        mf::LogInfo("CorsikaGen") << "Selected"<<selectedflist.back().first<<"\n";
          }else{
        //use findMatchingFiles
        std::vector<std::pair<std::string,long>> flist;
                std::string path(gSystem->DirName(fShowerInputFiles[i].c_str()));
                std::string pattern(gSystem->BaseName(fShowerInputFiles[i].c_str()));
                flist = fIFDH->findMatchingFiles(path,pattern);
                unsigned int selIndex=-1;
                if(flist.size()==1){ //0th element is the search path:pattern
                        selIndex=0;
                }else if(flist.size()>1){
                        selIndex= (unsigned int) (flat()*(flist.size()-1)+0.5); //rnd with rounding, dont allow picking the 0th element
                }else{
                        throw cet::exception("CORSIKAGen") << "No files returned for path:pattern: "<<path<<":"<<pattern<<std::endl;
                }
                selectedflist.push_back(flist[selIndex]);
                mf::LogInfo("CorsikaGen") << "For "<<fShowerInputFiles[i]<<":"<<pattern
        <<"\nFound "<< flist.size() << " candidate files"
        <<"\nChoosing file number "<< selIndex << "\n"
        <<"\nSelected "<<selectedflist.back().first<<"\n";
     }

    }
    
    //do the fetching, store local filepaths in locallist
    std::vector<std::string> locallist;
    for(unsigned int i=0; i<selectedflist.size(); i++){
      mf::LogInfo("CorsikaGen")
        << "Fetching: "<<selectedflist[i].first<<" "<<selectedflist[i].second<<"\n";
      std::string fetchedfile(fIFDH->fetchInput(selectedflist[i].first));
      LOG_DEBUG("CorsikaGen") << "Fetched; local path: "<<fetchedfile;
      locallist.push_back(fetchedfile);
    }
    
    //open the files in fShowerInputFilesLocalPaths with sqlite3
    for(unsigned int i=0; i<locallist.size(); i++){
      //prepare and execute statement to attach db file
      int res=sqlite3_open(locallist[i].c_str(),&fdb[i]);
      if (res!= SQLITE_OK)
        throw cet::exception("CORSIKAGen") << "Error opening db: (" <<locallist[i].c_str()<<") ("<<res<<"): " << sqlite3_errmsg(fdb[i]) << "; memory used:<<"<<sqlite3_memory_used()<<"/"<<sqlite3_memory_highwater(0)<<"\n";
      else
        mf::LogInfo("CORSIKAGen")<<"Attached db "<< locallist[i]<<"\n";
    }
  }

  double CORSIKAGen::wrapvar( const double var, const double low, const double high){
    //wrap variable so that it's always between low and high
    return (var - (high - low) * floor(var/(high-low))) + low;
  }

  double CORSIKAGen::wrapvarBoxNo( const double var, const double low, const double high, int& boxno){
    //wrap variable so that it's always between low and high
    boxno=int(floor(var/(high-low)));
    return (var - (high - low) * floor(var/(high-low))) + low;
  }
  
  void CORSIKAGen::populateTOffset(){
    //populate TOffset_corsika by finding minimum ParticleTime from db file
    
    sqlite3_stmt *statement;
    const std::string kStatement("select min(t) from particles");
    double t=0.;
    
    for(int i=0; i<fShowerInputs; i++){
        //build and do query to get run min(t) from each db
        if ( sqlite3_prepare(fdb[i], kStatement.c_str(), -1, &statement, 0 ) == SQLITE_OK ){
          int res=0;
          res = sqlite3_step(statement);
          if ( res == SQLITE_ROW ){
            t=sqlite3_column_double(statement,0);
            mf::LogInfo("CORSIKAGen")<<"For showers input "<< i<<" found particles.min(t)="<<t<<"\n";
            if (i==0 || t<fToffset_corsika) fToffset_corsika=t;
          }else{
            throw cet::exception("CORSIKAGen") << "Unexpected sqlite3_step return value: (" <<res<<"); "<<"ERROR:"<<sqlite3_errmsg(fdb[i])<<"\n";
          }         
        }else{
          throw cet::exception("CORSIKAGen") << "Error preparing statement: (" <<kStatement<<"); "<<"ERROR:"<<sqlite3_errmsg(fdb[i])<<"\n";
        }
    }
    
    mf::LogInfo("CORSIKAGen")<<"Found corsika timeoffset [ns]: "<< fToffset_corsika<<"\n";
  }
  
  void CORSIKAGen::populateNShowers(){
    //populate vector of the number of showers per event based on:
      //AREA the showers are being distributed over
      //TIME of the event (fSampleTime)
      //flux constants that determine the overall normalizations (fShowerFluxConstants)
      //Energy range over which the sample was generated (ERANGE_*)
      //power spectrum over which the sample was generated (ESLOPE)
  
    
    //compute shower area based on the maximal x,z dimensions of cryostat boundaries + fShowerAreaExtension
    art::ServiceHandle<geo::Geometry> geom;
    for(unsigned int c = 0; c < geom->Ncryostats(); ++c){
      double bounds[6] = {0.};
      geom->CryostatBoundaries(bounds, c); 
      for (unsigned int bnd = 0; bnd<6; bnd++){
        mf::LogVerbatim("CORSIKAGen")<<"Cryo Boundary: "<<bnd<<"="<<bounds[bnd]<<" ( + Buffer="<<fBuffBox[bnd]<<")\n";
        if(fabs(bounds[bnd])>fabs(fShowerBounds[bnd])){
          fShowerBounds[bnd]=bounds[bnd];
        }
      } 
    }
    //add on fShowerAreaExtension without being clever
    fShowerBounds[0] = fShowerBounds[0] - fShowerAreaExtension;
    fShowerBounds[1] = fShowerBounds[1] + fShowerAreaExtension;
    fShowerBounds[4] = fShowerBounds[4] - fShowerAreaExtension;
    fShowerBounds[5] = fShowerBounds[5] + fShowerAreaExtension;
    
    double showersArea=(fShowerBounds[1]/100-fShowerBounds[0]/100)*(fShowerBounds[5]/100-fShowerBounds[4]/100);
    
    mf::LogInfo("CORSIKAGen")
      <<  "Area extended by : "<<fShowerAreaExtension
      <<"\nShowers to be distributed betweeen: x="<<fShowerBounds[0]<<","<<fShowerBounds[1]
                             <<" & z="<<fShowerBounds[4]<<","<<fShowerBounds[5]
      <<"\nShowers to be distributed with random XZ shift: "<<fRandomXZShift<<" cm"
      <<"\nShowers to be distributed over area: "<<showersArea<<" m^2"
      <<"\nShowers to be distributed over time: "<<fSampleTime<<" s"
      <<"\nShowers to be distributed with time offset: "<<fToffset<<" s"
      <<"\nShowers to be distributed at y: "<<fShowerBounds[3]<<" cm"
      ;
    
    //db variables
    sqlite3_stmt *statement;
    const std::string kStatement("select erange_high,erange_low,eslope,nshow from input");
    double upperLimitOfEnergyRange=0.,lowerLimitOfEnergyRange=0.,energySlope=0.,oneMinusGamma=0.,EiToOneMinusGamma=0.,EfToOneMinusGamma=0.;
    
    /*
    // get random number generator engine... currently unused here
    art::ServiceHandle<art::RandomNumberGenerator> rng;
    CLHEP::HepRandomEngine &engine = rng->getEngine("gen");
    CLHEP::RandFlat flat(engine);
    */
    
    for(int i=0; i<fShowerInputs; i++){
        //build and do query to get run info from databases
      //  double thisrnd=flat();//need a new random number for each query
        if ( sqlite3_prepare(fdb[i], kStatement.c_str(), -1, &statement, 0 ) == SQLITE_OK ){
          int res=0;
          res = sqlite3_step(statement);
          if ( res == SQLITE_ROW ){
            upperLimitOfEnergyRange=sqlite3_column_double(statement,0);
            lowerLimitOfEnergyRange=sqlite3_column_double(statement,1);
            energySlope = sqlite3_column_double(statement,2);
            fMaxShowers.push_back(sqlite3_column_int(statement,3));
            oneMinusGamma = 1 + energySlope;
            EiToOneMinusGamma = pow(lowerLimitOfEnergyRange, oneMinusGamma);
            EfToOneMinusGamma = pow(upperLimitOfEnergyRange, oneMinusGamma);
            mf::LogVerbatim("CORSIKAGen")<<"For showers input "<< i<<" found e_hi="<<upperLimitOfEnergyRange<<", e_lo="<<lowerLimitOfEnergyRange<<", slope="<<energySlope<<", k="<<fShowerFluxConstants[i]<<"\n";
          }else{
            throw cet::exception("CORSIKAGen") << "Unexpected sqlite3_step return value: (" <<res<<"); "<<"ERROR:"<<sqlite3_errmsg(fdb[i])<<"\n";
          }         
        }else{
          throw cet::exception("CORSIKAGen") << "Error preparing statement: (" <<kStatement<<"); "<<"ERROR:"<<sqlite3_errmsg(fdb[i])<<"\n";
        }
      
      //this is computed, how?
      double NShowers=( M_PI * showersArea * fShowerFluxConstants[i] * (EfToOneMinusGamma - EiToOneMinusGamma) / oneMinusGamma )*fSampleTime; 
      fNShowersPerEvent.push_back(NShowers);
      mf::LogVerbatim("CORSIKAGen")<<"For showers input "<< i
                               <<" the number of showers per event is "<<(int)NShowers<<"\n";
    }
  }
  
  void CORSIKAGen::GetSample(simb::MCTruth& mctruth){
    //for each input, randomly pull fNShowersPerEvent[i] showers from the Particles table
    //and randomly place them in time (between -fSampleTime/2 and fSampleTime/2)
    //wrap their positions based on the size of the area under consideration
    //based on http://nusoft.fnal.gov/larsoft/doxsvn/html/CRYHelper_8cxx_source.html (Sample)
    
    //query from sqlite db with select * from particles where shower in (select id from showers ORDER BY substr(id*0.51123124141,length(id)+2) limit 100000) ORDER BY substr(shower*0.51123124141,length(shower)+2);
    //where 0.51123124141 is a random seed to allow randomly selecting rows and should be randomly generated for each query
    //the inner order by is to select randomly from the possible shower id's
    //the outer order by is to make sure the shower numbers are ordered randomly (without this, the showers always come out ordered by shower number
    //and 100000 is the number of showers to be selected at random and needs to be less than the number of showers in the showers table 
    
    //TDatabasePDG is for looking up particle masses
    static TDatabasePDG* pdgt = TDatabasePDG::Instance();
    
    //db variables
    sqlite3_stmt *statement;
    const TString kStatement("select shower,pdg,px,py,pz,x,z,t,e from particles where shower in (select id from showers ORDER BY substr(id*%f,length(id)+2) limit %d) ORDER BY substr(shower*%f,length(shower)+2)");

    //get rng engine
    art::ServiceHandle<art::RandomNumberGenerator> rng;
    CLHEP::HepRandomEngine &engine = rng->getEngine("gen");
    CLHEP::RandFlat flat(engine);

    CLHEP::HepRandomEngine &engine_pois = rng->getEngine("pois");
    CLHEP::RandPoissonQ randpois(engine_pois);

    // get geometry and figure where to project particles to, based on CRYHelper
    art::ServiceHandle<geo::Geometry> geom;
    double x1, x2;
    double y1, y2;
    double z1, z2;
    geom->WorldBox(&x1, &x2, &y1, &y2, &z1, &z2);  

    // make the world box slightly smaller so that the projection to 
    // the edge avoids possible rounding errors later on with Geant4
    double fBoxDelta=1.e-5;
    x1 += fBoxDelta;
    x2 -= fBoxDelta;
    y1 += fBoxDelta;
    y2 = fProjectToHeight;
    z1 += fBoxDelta;
    z2 -= fBoxDelta;
               
    //populate mctruth
    int ntotalCtr=0; //count number of particles added to mctruth
    int lastShower=0; //keep track of last shower id so that t can be randomized on every new shower
    int nShowerCntr=0; //keep track of how many showers are left to be added to mctruth
    int nShowerQry=0; //number of showers to query from db
    int shower,pdg;
    double px,py,pz,x,z,tParticleTime,etot,showerTime=0.,showerTimex=0.,showerTimez=0.,showerXOffset=0.,showerZOffset=0.,t;
    for(int i=0; i<fShowerInputs; i++){
      nShowerCntr=randpois.fire(fNShowersPerEvent[i]);
      mf::LogInfo("CORSIKAGEN") << " Shower input " << i << " with mean " << fNShowersPerEvent[i] << " generating " << nShowerCntr;

      while(nShowerCntr>0){
        //how many showers should we query?
        if(nShowerCntr>fMaxShowers[i]){
          nShowerQry=fMaxShowers[i]; //take the group size
        }else{
          nShowerQry=nShowerCntr; //take the rest that are needed
        }
        //build and do query to get nshowers
        double thisrnd=flat(); //need a new random number for each query
        TString kthisStatement=TString::Format(kStatement.Data(),thisrnd,nShowerQry,thisrnd);
        LOG_DEBUG("CORSIKAGen")<<"Executing: "<<kthisStatement;
        if ( sqlite3_prepare(fdb[i], kthisStatement.Data(), -1, &statement, 0 ) == SQLITE_OK ){
          int res=0;
          //loop over database rows, pushing particles into mctruth object
          while(1){
            res = sqlite3_step(statement);
            if ( res == SQLITE_ROW ){
              shower=sqlite3_column_int(statement,0);
              if(shower!=lastShower){
                //each new shower gets its own random time and position offsets
                showerTime=1e9*(flat()*fSampleTime); //converting from s to ns
                showerTimex=1e9*(flat()*fSampleTime); //converting from s to ns
                showerTimez=1e9*(flat()*fSampleTime); //converting from s to ns
                //and a random offset in both z and x controlled by the fRandomXZShift parameter
                showerXOffset=flat()*fRandomXZShift - (fRandomXZShift/2);
                showerZOffset=flat()*fRandomXZShift - (fRandomXZShift/2);
              } 
              pdg=sqlite3_column_int(statement,1);
              //get mass for this particle
              double m = 0.; // in GeV
              TParticlePDG* pdgp = pdgt->GetParticle(pdg);
              if (pdgp) m = pdgp->Mass();
              
              //Note: position/momentum in db have north=-x and west=+z, rotate so that +z is north and +x is west
              //get momentum components
              px=sqlite3_column_double(statement,4);//uboone x=Particlez
              py=sqlite3_column_double(statement,3);
              pz=-sqlite3_column_double(statement,2);//uboone z=-Particlex
              etot=sqlite3_column_double(statement,8);
              
              //get/calculate position components
              int boxnoX=0,boxnoZ=0;
              x=wrapvarBoxNo(sqlite3_column_double(statement,6)+showerXOffset,fShowerBounds[0],fShowerBounds[1],boxnoX);
              z=wrapvarBoxNo(-sqlite3_column_double(statement,5)+showerZOffset,fShowerBounds[4],fShowerBounds[5],boxnoZ);
              tParticleTime=sqlite3_column_double(statement,7); //time offset, includes propagation time from top of atmosphere
              //actual particle time is particle surface arrival time
              //+ shower start time
              //+ global offset (fcl parameter, in s)
              //- propagation time through atmosphere
              //+ boxNo{X,Z} time offset to make grid boxes have different shower times
              t=tParticleTime+showerTime+(1e9*fToffset)-fToffset_corsika + showerTimex*boxnoX + showerTimez*boxnoZ;
              //wrap surface arrival so that it's in the desired time window
              t=wrapvar(t,(1e9*fToffset),1e9*(fToffset+fSampleTime));
              
              simb::MCParticle p(ntotalCtr,pdg,"primary",-200,m,1);
              
              //project back to wordvol/fProjectToHeight
              double xyzo[3];
              double x0[3]={x,fShowerBounds[3],z};
              double dx[3]={px,py,pz};
              this->ProjectToBoxEdge(x0, dx, x1, x2, y1, y2, z1, z2, xyzo);
                            
              TLorentzVector pos(xyzo[0],xyzo[1],xyzo[2],t);// time needs to be in ns to match GENIE, etc
              TLorentzVector mom(px,py,pz,etot);
              p.AddTrajectoryPoint(pos,mom);
              mctruth.Add(p);
              ntotalCtr++;
              lastShower=shower;
            }else if ( res == SQLITE_DONE ){
              break;
            }else{
              throw cet::exception("CORSIKAGen") << "Unexpected sqlite3_step return value: (" <<res<<"); "<<"ERROR:"<<sqlite3_errmsg(fdb[i])<<"\n";
            }
          }
        }else{
          throw cet::exception("CORSIKAGen") << "Error preparing statement: (" <<kthisStatement<<"); "<<"ERROR:"<<sqlite3_errmsg(fdb[i])<<"\n";
        }
        nShowerCntr=nShowerCntr-nShowerQry;
      }
    }
  }

  void CORSIKAGen::reconfigure(fhicl::ParameterSet const& p){
  
    return;
  }

  void CORSIKAGen::beginJob(){
    art::ServiceHandle<art::TFileService> tfs;


  }

  void CORSIKAGen::beginRun(art::Run& run){

    // grab the geometry object to see what geometry we are using
    art::ServiceHandle<geo::Geometry> geo;

    std::unique_ptr<sumdata::RunData> runcol(new sumdata::RunData(geo->DetectorName()));

    run.put(std::move(runcol));

    return;
  }

  void CORSIKAGen::produce(art::Event& evt){
    std::unique_ptr< std::vector<simb::MCTruth> > truthcol(new std::vector<simb::MCTruth>);

    art::ServiceHandle<geo::Geometry> geom;
    
    simb::MCTruth truth;
    truth.SetOrigin(simb::kCosmicRay);
    
    simb::MCTruth pretruth;
    GetSample(pretruth);
    mf::LogInfo("CORSIKAGen")<<"GetSample number of particles returned: "<<pretruth.NParticles()<<"\n";
    // loop over particles in the truth object
    for(int i = 0; i < pretruth.NParticles(); ++i){
      simb::MCParticle particle = pretruth.GetParticle(i);
      const TLorentzVector& v4 = particle.Position();
      const TLorentzVector& p4 = particle.Momentum();
      double x0[3] = {v4.X(),  v4.Y(),  v4.Z() };
      double dx[3] = {p4.Px(), p4.Py(), p4.Pz()};

      // now check if the particle goes through any cryostat in the detector
      // if so, add it to the truth object.
      for(unsigned int c = 0; c < geom->Ncryostats(); ++c){
        double bounds[6] = {0.};
        geom->CryostatBoundaries(bounds, c);
    
        //add a buffer box around the cryostat bounds to increase the acceptance and account for scattering
        //By default, the buffer box has zero size
        for (unsigned int cb=0; cb<6; cb++)
           bounds[cb] = bounds[cb]+fBuffBox[cb];
        
        //calculate the intersection point with each cryostat surface
        bool intersects_cryo = false;
        for (int bnd=0; bnd!=6; ++bnd) {
          if (bnd<2) {
            double p2[3] = {bounds[bnd],  x0[1] + (dx[1]/dx[0])*(bounds[bnd] - x0[0]), x0[2] + (dx[2]/dx[0])*(bounds[bnd] - x0[0])};
            if ( p2[1] >= bounds[2] && p2[1] <= bounds[3] && 
                 p2[2] >= bounds[4] && p2[2] <= bounds[5] ) {
              intersects_cryo = true;
              break;
            }
          }
          else if (bnd>=2 && bnd<4) {
            double p2[3] = {x0[0] + (dx[0]/dx[1])*(bounds[bnd] - x0[1]), bounds[bnd], x0[2] + (dx[2]/dx[1])*(bounds[bnd] - x0[1])};
            if ( p2[0] >= bounds[0] && p2[0] <= bounds[1] && 
                 p2[2] >= bounds[4] && p2[2] <= bounds[5] ) {
              intersects_cryo = true;
        break;
            }
          }
          else if (bnd>=4) {
            double p2[3] = {x0[0] + (dx[0]/dx[2])*(bounds[bnd] - x0[2]), x0[1] + (dx[1]/dx[2])*(bounds[bnd] - x0[2]), bounds[bnd]};
            if ( p2[0] >= bounds[0] && p2[0] <= bounds[1] && 
                 p2[1] >= bounds[2] && p2[1] <= bounds[3] ) {
              intersects_cryo = true;
        break;
            }
          }
        }

        if (intersects_cryo){
          truth.Add(particle);
          break; //leave loop over cryostats to avoid adding particle multiple times  
        }// end if particle goes into a cryostat
      }// end loop over cryostats in the detector

    }// loop on particles
    
    mf::LogInfo("CORSIKAGen")<<"Number of particles from getsample crossing cryostat + bounding box: "<<truth.NParticles()<<"\n";

    truthcol->push_back(truth);
    evt.put(std::move(truthcol));
  
    return;
  }// end produce

}// end namespace


namespace evgen{

  DEFINE_ART_MODULE(CORSIKAGen)

}

#endif // EVGEN_CORSIKAGen_H