BCRooInterface.cxx

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#include <RooGlobalFunc.h>
#include <RooMsgService.h>
#include <RooProdPdf.h>
#include <RooRealVar.h>
#include <RooWorkspace.h>
#include <TFile.h>

#include <BAT/BCMath.h>
#include <iostream>

#include "BCRooInterface.h"

// ---------------------------------------------------------
void BCRooInterface::Initialize( RooAbsData& data,
             RooAbsPdf& model,
             RooAbsPdf& prior_trans,
             const RooArgSet* params,
             const RooArgSet& listPOI )
{

  fData = &data;
  fModel = &model;

  // make the product of both priors to get the full prior probability function
  RooAbsPdf* prior_total = &prior_trans;
  if (prior_total!=0 ) {
    fPrior = prior_total;
  }
  else {
      std::cout << "No prior PDF: the program will crash\n";
  }

  std::cout << "Imported parameters:\n";
  fParams  = new RooArgList(listPOI);
  const RooArgSet* paramsTmp = params;
  if (paramsTmp!=0)
    fParams->add(*paramsTmp);
  fParams->Print("v");

  // create the log-likelihood function
//   fNll = new RooNLLVar("fNll","",*fModel,*fData,true/*extended*/);

  RooArgSet* constrainedParams = fModel->getParameters(*fData);
  fNll = fModel->createNLL(*fData, RooFit::Constrain(*constrainedParams) );

  DefineParameters();
}

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

void BCRooInterface::Initialize( const char* rootFile,
             const char* wsName,
             const char* dataName,
             const char* modelName,
             const char* priorName,
             const char* priorNuisanceName,
             const char* paramsName,
             const char* listPOIName )
{
  // retrieve the RooFit inputs from the ROOT file

  /*
  // hard coded names in the workspace
  char* rootFile = "bat_workspace.root";
  char* wsName= "batWS";
  char* dataName= "data";
  char* modelName= "model";
  char* priorName= "priorPOI";
  char* priorNuisanceName= "priorNuisance";
  char* paramsName= "parameters";
  char* listPOIName= "POI";
  */

   std::cout << "Opening " << rootFile << std::endl;
   TFile* file = new TFile(rootFile);
   std::cout << "content :\n";
   file->ls();

   RooWorkspace* bat_ws = (RooWorkspace*) file->Get(wsName);
   bat_ws->Print("v");

   fData = (RooAbsData*) bat_ws->data(dataName);
   fModel = (RooAbsPdf*) bat_ws->function(modelName);

   // make the product of both priors to get the full prior probability function
   RooAbsPdf* priorPOI = (RooAbsPdf*) bat_ws->function(priorName);
   RooAbsPdf* priorNuisance = (RooAbsPdf*) bat_ws->pdf(priorNuisanceName);
   if (priorNuisance!=0 && priorPOI!=0) {
      fPrior = new RooProdPdf("fPrior","complete prior",*priorPOI,*priorNuisance);
   }
   else {
      if ( priorNuisance!=0 )
         fPrior=priorNuisance;
      else if ( priorPOI!=0 )
         fPrior = priorPOI;
      else
         std::cout << "No prior PDF: the program will crash\n";
   }

   std::cout << "Imported parameters:\n";
   fParams  = new RooArgList(*(bat_ws->set(listPOIName)));
   RooArgSet* paramsTmp = (RooArgSet*) bat_ws->set(paramsName);
   if (paramsTmp!=0) fParams->add(*paramsTmp);
   fParams->Print("v");

   // create the log-likelihood function
   //fNll = new RooNLLVar("fNll","",*fModel,*fData,true/*extended*/);
   RooArgSet* constrainedParams = fModel->getParameters(*fData);
   fNll = fModel->createNLL(*fData, RooFit::Constrain(*constrainedParams) );

   file->Close();

   DefineParameters();
}


// ---------------------------------------------------------
BCRooInterface::BCRooInterface() : BCModel()
{  // default constructor

}

// ---------------------------------------------------------
BCRooInterface::BCRooInterface(const char* name) : BCModel(name)
{  // another constructor

}

// ---------------------------------------------------------
BCRooInterface::~BCRooInterface()
{  // default destructor

}

// ---------------------------------------------------------
void BCRooInterface::DefineParameters()
{  // define for BAT the list of parameters, range and plot binning

  int default_nbins = 500;

  int nParams = fParams->getSize();
  for (int iParam=0; iParam<nParams; iParam++) {
    RooRealVar* ipar = (RooRealVar*) fParams->at(iParam);
    this->AddParameter(ipar->GetName(),ipar->getMin(),ipar->getMax());
    this->SetNbins(ipar->GetName(),default_nbins);
    std::cout << "added parameter: " << ipar->GetName() << " defined in range [ " << ipar->getMin() << " - " << ipar->getMax() << " ]\n";
  }
}

// ---------------------------------------------------------
double BCRooInterface::LogLikelihood(std::vector <double> parameters)
{  // this methods returns the logarithm of the conditional probability: p(data|parameters)

   // retrieve the values of the parameters to be tested
  int nParams = fParams->getSize();
  for (int iParam=0; iParam<nParams; iParam++) {
    RooRealVar* ipar = (RooRealVar*) fParams->at(iParam);
    ipar->setVal(parameters.at(iParam));
  }

  // compute the log of the likelihood function
  double logprob = -fNll->getVal();
  return logprob;
}

// ---------------------------------------------------------
double BCRooInterface::LogAPrioriProbability(std::vector <double> parameters)
{  // this method returs the logarithm of the prior probability for the parameters: p(parameters).

   // retrieve the values of the parameters to be tested
  int nParams = fParams->getSize();
  for (int iParam=0; iParam<nParams; iParam++) {
    RooRealVar* ipar = (RooRealVar*) fParams->at(iParam);
    ipar->setVal(parameters.at(iParam));
  }

  // compute the log of the prior function
  RooArgSet* tmpArgSet = new RooArgSet(*fParams);
  double prob = fPrior->getVal(tmpArgSet);
  delete tmpArgSet;
  if (prob<1e-300)
    prob = 1e-300;
  return log(prob);
}