/data/refman/pasoursint/CMSSW_6_1_2_SLHC2/src/PhysicsTools/Utilities/src/Lumi3DReWeighting.cc

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#ifndef PhysicsTools_Utilities_interface_Lumi3DReWeighting_cc
#define PhysicsTools_Utilities_interface_Lumi3DReWeighting_cc


#include "TRandom1.h"
#include "TRandom2.h"
#include "TRandom3.h"
#include "TStopwatch.h"
#include "TH1.h"
#include "TH3.h"
#include "TFile.h"
#include <string>
#include <algorithm>
#include <boost/shared_ptr.hpp>
#include "SimDataFormats/PileupSummaryInfo/interface/PileupSummaryInfo.h" 
#include "PhysicsTools/Utilities/interface/Lumi3DReWeighting.h"
#include "DataFormats/Common/interface/Handle.h"
#include "DataFormats/Provenance/interface/ProcessHistory.h"
#include "DataFormats/Provenance/interface/Provenance.h"
#include "FWCore/Common/interface/EventBase.h"

using namespace edm;

Lumi3DReWeighting::Lumi3DReWeighting( std::string generatedFile,
                                      std::string dataFile,
                                      std::string GenHistName = "pileup",
                                      std::string DataHistName = "pileup", 
                                      std::string WeightOutputFile ="") :
      generatedFileName_( generatedFile), 
      dataFileName_     ( dataFile ), 
      GenHistName_      ( GenHistName ), 
      DataHistName_     ( DataHistName ),
      weightFileName_   (WeightOutputFile)
      {
        generatedFile_ = boost::shared_ptr<TFile>( new TFile(generatedFileName_.c_str()) ); //MC distribution
        dataFile_      = boost::shared_ptr<TFile>( new TFile(dataFileName_.c_str()) );      //Data distribution

        boost::shared_ptr<TH1> Data_temp = boost::shared_ptr<TH1>(  (static_cast<TH1*>(dataFile_->Get( DataHistName_.c_str() )->Clone() )) );

        boost::shared_ptr<TH1> MC_temp = boost::shared_ptr<TH1>(  (static_cast<TH1*>(generatedFile_->Get( GenHistName_.c_str() )->Clone() )) );


        MC_distr_ = boost::shared_ptr<TH1>(  (static_cast<TH1*>(generatedFile_->Get( GenHistName_.c_str() )->Clone() )) );
        Data_distr_ = boost::shared_ptr<TH1>(  (static_cast<TH1*>(dataFile_->Get( DataHistName_.c_str() )->Clone() )) );

        // MC * data/MC = data, so the weights are data/MC:

        // normalize both histograms first

        Data_distr_->Scale( 1.0/ Data_distr_->Integral() );
        MC_distr_->Scale( 1.0/ MC_distr_->Integral() );

}

Lumi3DReWeighting::Lumi3DReWeighting( std::vector< float > MC_distr, std::vector< float > Lumi_distr,
                                      std::string WeightOutputFile ="") {

  weightFileName_ = WeightOutputFile;

  // no histograms for input: use vectors
  
  // now, make histograms out of them:

  Int_t NMCBins = MC_distr.size();

  MC_distr_ = boost::shared_ptr<TH1> ( new TH1F("MC_distr","MC dist",NMCBins,0., float(NMCBins)) );

  Int_t NDBins = Lumi_distr.size();

  Data_distr_ = boost::shared_ptr<TH1> ( new TH1F("Data_distr","Data dist",NDBins,0., float(NDBins)) );

  for(int ibin = 1; ibin<NMCBins+1; ++ibin ) {
    MC_distr_->SetBinContent(ibin,MC_distr[ibin-1]);
  }

  for(int ibin = 1; ibin<NDBins+1; ++ibin ) {
    Data_distr_->SetBinContent(ibin, Lumi_distr[ibin-1]);
  }

  // check integrals, make sure things are normalized

  float deltaH = Data_distr_->Integral();
  if(fabs(1.0 - deltaH) > 0.001 ) { //*OOPS*...
    Data_distr_->Scale( 1.0/ Data_distr_->Integral() );
  }
  float deltaMC = MC_distr_->Integral();
  if(fabs(1.0 - deltaMC) > 0.001 ) {
    MC_distr_->Scale(1.0/ MC_distr_->Integral());
  }

}


double Lumi3DReWeighting::weight3D( int pv1, int pv2, int pv3 ) {

  using std::min;

  int npm1 = min(pv1,49);
  int np0 = min(pv2,49);
  int npp1 = min(pv3,49);

  return Weight3D_[npm1][np0][npp1];

}

// This version does all of the work for you, just taking an event pointer as input

double Lumi3DReWeighting::weight3D( const edm::EventBase &e ) {

  using std::min;

  // get pileup summary information

  Handle<std::vector< PileupSummaryInfo > >  PupInfo;
  e.getByLabel(edm::InputTag("addPileupInfo"), PupInfo);

  std::vector<PileupSummaryInfo>::const_iterator PVI;

  int npm1=-1;
  int np0=-1;
  int npp1=-1;
 
  for(PVI = PupInfo->begin(); PVI != PupInfo->end(); ++PVI) {

    int BX = PVI->getBunchCrossing();

    if(BX == -1) { 
      npm1 = PVI->getPU_NumInteractions();
    }
    if(BX == 0) { 
      np0 = PVI->getPU_NumInteractions();
    }
    if(BX == 1) { 
      npp1 = PVI->getPU_NumInteractions();
    }

  }

  npm1 = min(npm1,49);
  np0 = min(np0,49);
  npp1 = min(npp1,49);

  //  std::cout << " vertices " << npm1 << " " << np0 << " " << npp1 << std::endl; 

  return Weight3D_[npm1][np0][npp1];
 
}

void Lumi3DReWeighting::weight3D_set( std::string generatedFile, std::string dataFile, std::string GenHistName, std::string DataHistName, std::string WeightOutputFile )
{
 
  generatedFileName_ = generatedFile;
  dataFileName_ = dataFile ; 
  GenHistName_ = GenHistName ; 
  DataHistName_= DataHistName ;
  weightFileName_  = WeightOutputFile;  
    
  std::cout<< " seting values: " << generatedFileName_ << " " << dataFileName_ << " " << GenHistName_ << " " << DataHistName_ << std::endl;

  generatedFile_ = boost::shared_ptr<TFile>( new TFile(generatedFileName_.c_str()) ); //MC distribution
  dataFile_      = boost::shared_ptr<TFile>( new TFile(dataFileName_.c_str()) );      //Data distribution
  
  boost::shared_ptr<TH1> Data_temp = boost::shared_ptr<TH1>(  (static_cast<TH1*>(dataFile_->Get( DataHistName_.c_str() )->Clone() )) );
  
  boost::shared_ptr<TH1> MC_temp = boost::shared_ptr<TH1>(  (static_cast<TH1*>(generatedFile_->Get( GenHistName_.c_str() )->Clone() )) );
  
  
  MC_distr_ = boost::shared_ptr<TH1>(  (static_cast<TH1*>(generatedFile_->Get( GenHistName_.c_str() )->Clone() )) );
  Data_distr_ = boost::shared_ptr<TH1>(  (static_cast<TH1*>(dataFile_->Get( DataHistName_.c_str() )->Clone() )) );
  
  // MC * data/MC = data, so the weights are data/MC:
  
  // normalize both histograms first
  
  Data_distr_->Scale( 1.0/ Data_distr_->Integral() );
  MC_distr_->Scale( 1.0/ MC_distr_->Integral() );
}

void Lumi3DReWeighting::weight3D_init( float ScaleFactor ) { 

  // Scale factor is used to shift target distribution (i.e. luminosity scale)  1. = no shift

  //create histogram to write output weights, save pain of generating them again...

  TH3D* WHist = new TH3D("WHist","3D weights",50,0.,50.,50,0.,50.,50,0.,50. );
  TH3D* DHist = new TH3D("DHist","3D weights",50,0.,50.,50,0.,50.,50,0.,50. );
  TH3D* MHist = new TH3D("MHist","3D weights",50,0.,50.,50,0.,50.,50,0.,50. );

  using std::min;

  if( MC_distr_->GetEntries() == 0 ) {
    std::cout << " MC and Data distributions are not initialized! You must call the Lumi3DReWeighting constructor. " << std::endl;
  }


  // arrays for storing number of interactions

  double MC_ints[50][50][50];
  double Data_ints[50][50][50];

  for (int i=0; i<50; i++) {
    for(int j=0; j<50; j++) {
      for(int k=0; k<50; k++) {
        MC_ints[i][j][k] = 0.;
        Data_ints[i][j][k] = 0.;
      }
    }
  }

  double factorial[50];
  double PowerSer[50];
  double base = 1.;

  factorial[0] = 1.;
  PowerSer[0]=1.;

  for (int i = 1; i<50; ++i) {
    base = base*float(i);
    factorial[i] = base;
  }


  double x;
  double xweight;
  double probi, probj, probk;
  double Expval, mean;
  int xi;

  // Get entries for Data, MC, fill arrays:

  int NMCbin = MC_distr_->GetNbinsX();

  for (int jbin=1;jbin<NMCbin+1;jbin++) {       
    x =  MC_distr_->GetBinCenter(jbin);
    xweight = MC_distr_->GetBinContent(jbin); //use as weight for matrix

    //for Summer 11, we have this int feature:
    xi = int(x);

    // Generate Poisson distribution for each value of the mean

    mean = double(xi);

    if(mean<0.) {
      throw cms::Exception("BadInputValue") << " Your histogram generates MC luminosity values less than zero!"
                                                << " Please Check.  Terminating." << std::endl;
    }


    if(mean==0.){
      Expval = 1.;
    }
    else {
      Expval = exp(-1.*mean);
    }

    base = 1.;

    for (int i = 1; i<50; ++i) {
      base = base*mean;
      PowerSer[i] = base; // PowerSer is mean^i
    }

    // compute poisson probability for each Nvtx in weight matrix

    for (int i=0; i<50; i++) {
      probi = PowerSer[i]/factorial[i]*Expval;
      for(int j=0; j<50; j++) {
        probj = PowerSer[j]/factorial[j]*Expval;
        for(int k=0; k<50; k++) {
          probk = PowerSer[k]/factorial[k]*Expval;
          // joint probability is product of event weights multiplied by weight of input distribution bin
          MC_ints[i][j][k] = MC_ints[i][j][k]+probi*probj*probk*xweight;
        }
      }
    }

  }
  
  int NDatabin = Data_distr_->GetNbinsX();

  for (int jbin=1;jbin<NDatabin+1;jbin++) {       
    mean =  (Data_distr_->GetBinCenter(jbin))*ScaleFactor;
    xweight = Data_distr_->GetBinContent(jbin);

    // Generate poisson distribution for each value of the mean

    if(mean<0.) {
      throw cms::Exception("BadInputValue") << " Your histogram generates Data luminosity values less than zero!"
                                                << " Please Check.  Terminating." << std::endl;
    }

    if(mean==0.){
      Expval = 1.;
    }
    else {
      Expval = exp(-1.*mean);
    }

    base = 1.;

    for (int i = 1; i<50; ++i) {
      base = base*mean;
      PowerSer[i] = base;
    }

    // compute poisson probability for each Nvtx in weight matrix                                                                  

    for (int i=0; i<50; i++) {
      probi = PowerSer[i]/factorial[i]*Expval;
      for(int j=0; j<50; j++) {
        probj = PowerSer[j]/factorial[j]*Expval;
        for(int k=0; k<50; k++) {
          probk = PowerSer[k]/factorial[k]*Expval;
          // joint probability is product of event weights multiplied by weight of input distribution bin
          Data_ints[i][j][k] = Data_ints[i][j][k]+probi*probj*probk*xweight;
        }
      }
    }

  }
 

  for (int i=0; i<50; i++) {  
    //if(i<5) std::cout << "i = " << i << std::endl;
    for(int j=0; j<50; j++) {
      for(int k=0; k<50; k++) {
        if( (MC_ints[i][j][k])>0.) {
          Weight3D_[i][j][k]  =  Data_ints[i][j][k]/MC_ints[i][j][k];
        }
        else {
          Weight3D_[i][j][k]  = 0.;
        }
        WHist->SetBinContent( i+1,j+1,k+1,Weight3D_[i][j][k] );
        DHist->SetBinContent( i+1,j+1,k+1,Data_ints[i][j][k] );
        MHist->SetBinContent( i+1,j+1,k+1,MC_ints[i][j][k] );
        //      if(i<5 && j<5 && k<5) std::cout << Weight3D_[i][j][k] << " " ;
      }
      //      if(i<5 && j<5) std::cout << std::endl;
    }
  }

  if(! weightFileName_.empty() ) { 
    std::cout << " 3D Weight Matrix initialized! " << std::endl;
    std::cout << " Writing weights to file " << weightFileName_ << " for re-use...  " << std::endl;


    TFile * outfile = new TFile(weightFileName_.c_str(),"RECREATE");
    WHist->Write();
    MHist->Write();
    DHist->Write();
    outfile->Write();
    outfile->Close();
    outfile->Delete();              
  }

  return;


}


void Lumi3DReWeighting::weight3D_init( std::string WeightFileName ) { 

  TFile *infile = new TFile(WeightFileName.c_str());
  TH1F *WHist = (TH1F*)infile->Get("WHist");

  // Check if the histogram exists           
  if (!WHist) {
    throw cms::Exception("HistogramNotFound") << " Could not find the histogram WHist in the file "
                                              << "in the file " << WeightFileName << "." << std::endl;
  }

  for (int i=0; i<50; i++) {  
    //    if(i<5) std::cout << "i = " << i << std::endl;
    for(int j=0; j<50; j++) {
      for(int k=0; k<50; k++) {
        Weight3D_[i][j][k] = WHist->GetBinContent(i+1,j+1,k+1);
        //      if(i<5 && j<5 && k<5) std::cout << Weight3D_[i][j][k] << " ";
      }
      //      if(i<5 && j<5) std::cout << std::endl;

    }
  }

  std::cout << " 3D Weight Matrix initialized! " << std::endl;

  return;


}

void Lumi3DReWeighting::weight3D_init( std::string MCWeightFileName, std::string DataWeightFileName ) { 

  TFile *infileMC = new TFile(MCWeightFileName.c_str());
  TH3D *MHist = (TH3D*)infileMC->Get("MHist");

  // Check if the histogram exists           
  if (!MHist) {
    throw cms::Exception("HistogramNotFound") << " Could not find the histogram MHist in the file "
                                              << "in the file " << MCWeightFileName << "." << std::endl;
  }

  TFile *infileD = new TFile(DataWeightFileName.c_str());
  TH3D *DHist = (TH3D*)infileD->Get("DHist");

  // Check if the histogram exists           
  if (!DHist) {
    throw cms::Exception("HistogramNotFound") << " Could not find the histogram DHist in the file "
                                              << "in the file " << DataWeightFileName << "." << std::endl;
  }

  for (int i=0; i<50; i++) {  
    for(int j=0; j<50; j++) {
      for(int k=0; k<50; k++) {
        Weight3D_[i][j][k] = DHist->GetBinContent(i+1,j+1,k+1)/MHist->GetBinContent(i+1,j+1,k+1);
      }
    }
  }

  std::cout << " 3D Weight Matrix initialized! " << std::endl;

  return;


}


#endif