RooHistConstraint.cxx

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/*****************************************************************************
 * Project: RooFit                                                           *
 *                                                                           *
 * This code was autogenerated by RooClassFactory                            *
 *****************************************************************************/

/** \class RooHistConstraint
 \ingroup Roofit

**/

#include "Riostream.h"

#include "RooHistConstraint.h"
#include "RooAbsReal.h"
#include "RooAbsCategory.h"
#include "RooParamHistFunc.h"
#include "RooRealVar.h"
#include <math.h>
#include "TMath.h"

using namespace std;

ClassImp(RooHistConstraint)

////////////////////////////////////////////////////////////////////////////////

RooHistConstraint::RooHistConstraint(const char *name, const char *title, const RooArgSet& phfSet, Int_t threshold) :
  RooAbsPdf(name,title),
  _gamma("gamma","gamma",this),
  _nominal("nominal","nominal",this),
  _nominalErr("nominalErr","nominalErr",this),
  _relParam(kTRUE)
{
  // Implementing constraint on sum of RooParamHists
  //
  // Step 1 - Create new gamma parameters for sum
  // Step 2 - Replace entries in gamma listproxy of components with new sum components
  // Step 3 - Implement constraints in terms of gamma sum parameters


  if (phfSet.getSize()==1) {

    RooParamHistFunc* phf = dynamic_cast<RooParamHistFunc*>(phfSet.first()) ;

    if (!phf) {
      coutE(InputArguments) << "RooHistConstraint::ctor(" << GetName()
             << ") ERROR: input object must be a RooParamHistFunc" << endl ;
      throw std::string("RoohistConstraint::ctor ERROR incongruent input arguments") ;
    }

    // Now populate nominal with parameters
    RooArgSet allVars ;
    for (Int_t i=0 ; i<phf->_dh.numEntries() ; i++) {
      phf->_dh.get(i) ;
      if (phf->_dh.weight()<threshold) {
   const char* vname = Form("%s_nominal_bin_%i",GetName(),i) ;
   RooRealVar* var = new RooRealVar(vname,vname,0,1000) ;
   var->setVal(phf->_dh.weight()) ;
   var->setConstant(kTRUE) ;
   allVars.add(*var) ;
   _nominal.add(*var) ;
   RooRealVar* gam = (RooRealVar*) phf->_p.at(i) ;
   if (var->getVal()>0) {
     gam->setConstant(kFALSE) ;
   }
   _gamma.add(*gam) ;
      }
    }
    addOwnedComponents(allVars) ;

    return ;
  }



  RooFIter phiter = phfSet.fwdIterator() ;
  RooAbsArg* arg ;
  Int_t nbins(-1) ;
  vector<RooParamHistFunc*> phvec ;
  RooArgSet gammaSet ;
  string bin0_name ;
  while((arg=phiter.next())) {

    RooParamHistFunc* phfComp = dynamic_cast<RooParamHistFunc*>(arg) ;
    if (phfComp) {
      phvec.push_back(phfComp) ;
      if (nbins==-1) {
   nbins = phfComp->_p.getSize() ;
   bin0_name = phfComp->_p.at(0)->GetName() ;
   gammaSet.add(phfComp->_p) ;
      } else {
   if (phfComp->_p.getSize()!=nbins) {
     coutE(InputArguments) << "RooHistConstraint::ctor(" << GetName()
            << ") ERROR: incongruent input arguments: all input RooParamHistFuncs should have same #bins" << endl ;
     throw std::string("RoohistConstraint::ctor ERROR incongruent input arguments") ;
   }
   if (bin0_name != phfComp->_p.at(0)->GetName()) {
     coutE(InputArguments) << "RooHistConstraint::ctor(" << GetName()
            << ") ERROR: incongruent input arguments: all input RooParamHistFuncs should have the same bin parameters" << endl ;
     throw std::string("RoohistConstraint::ctor ERROR incongruent input arguments") ;
   }

      }
    } else {
      coutW(InputArguments) << "RooHistConstraint::ctor(" << GetName()
             << ") WARNING: ignoring input argument " << arg->GetName() << " which is not of type RooParamHistFunc" << endl;
    }
  }

  _gamma.add(gammaSet) ;

  // Now populate nominal and nominalErr with parameters
  RooArgSet allVars ;
  for (Int_t i=0 ; i<nbins ; i++) {

    Double_t sumVal(0) ;
    for (vector<RooParamHistFunc*>::iterator iter = phvec.begin() ; iter != phvec.end() ; ++iter) {
      sumVal += (*iter)->getNominal(i) ;
    }

    if (sumVal<threshold) {

      const char* vname = Form("%s_nominal_bin_%i",GetName(),i) ;
      RooRealVar* var = new RooRealVar(vname,vname,0,1000) ;

      Double_t sumVal2(0) ;
      for (vector<RooParamHistFunc*>::iterator iter = phvec.begin() ; iter != phvec.end() ; ++iter) {
   sumVal2 += (*iter)->getNominal(i) ;
      }
      var->setVal(sumVal2) ;
      var->setConstant(kTRUE) ;

      vname = Form("%s_nominal_error_bin_%i",GetName(),i) ;
      RooRealVar* vare = new RooRealVar(vname,vname,0,1000) ;

      Double_t sumErr2(0) ;
      for (vector<RooParamHistFunc*>::iterator iter = phvec.begin() ; iter != phvec.end() ; ++iter) {
   sumErr2 += pow((*iter)->getNominalError(i),2) ;
      }
      vare->setVal(sqrt(sumErr2)) ;
      vare->setConstant(kTRUE) ;

      allVars.add(RooArgSet(*var,*vare)) ;
      _nominal.add(*var) ;
      _nominalErr.add(*vare) ;

      ((RooRealVar*)_gamma.at(i))->setConstant(kFALSE) ;

    }
  }
  addOwnedComponents(allVars) ;
}

////////////////////////////////////////////////////////////////////////////////

 RooHistConstraint::RooHistConstraint(const RooHistConstraint& other, const char* name) :
   RooAbsPdf(other,name),
   _gamma("gamma",this,other._gamma),
   _nominal("nominal",this,other._nominal),
   _nominalErr("nominalErr",this,other._nominalErr),
   _relParam(other._relParam)
 {
 }

////////////////////////////////////////////////////////////////////////////////

 Double_t RooHistConstraint::evaluate() const
 {
   Double_t prod(1) ;
   RooFIter niter = _nominal.fwdIterator() ;
   RooFIter giter = _gamma.fwdIterator() ;
   RooAbsReal *gam, *nom ;
   while ((gam = (RooAbsReal*) giter.next())) {
     nom = (RooAbsReal*) niter.next() ;
     Double_t gamVal = gam->getVal() ;
     if (_relParam) gamVal *= nom->getVal() ;
     Double_t pois = TMath::Poisson(nom->getVal(),gamVal) ;
     prod *= pois ;
   }
   return prod ;
 }

////////////////////////////////////////////////////////////////////////////////

Double_t RooHistConstraint::getLogVal(const RooArgSet* /*set*/) const
{
   Double_t sum(0) ;
   RooFIter niter = _nominal.fwdIterator() ;
   RooFIter giter = _gamma.fwdIterator() ;
   RooAbsReal *gamv, *nomv ;
   while ((gamv = (RooAbsReal*) giter.next())) {
     nomv = (RooAbsReal*) niter.next() ;
     Double_t gam = gamv->getVal() ;
     Int_t    nom = (Int_t) nomv->getVal() ;
     if (_relParam) gam *= nom ;
     if (gam>0) {
       Double_t logPoisson = nom*log(gam) - gam - logSum(nom) ;
       sum += logPoisson ;
     } else if (nom>0) {
       cout << "ERROR gam=0 and nom>0" << endl ;
     }
   }
   return sum ;
}

////////////////////////////////////////////////////////////////////////////////

Double_t RooHistConstraint::logSum(Int_t i) const
{
  static Double_t* _lut = 0 ;
  if (!_lut) {
    _lut = new Double_t[5000] ;
    for (Int_t ii=0 ; ii<5000 ; ii++) _lut[ii] = 0 ;

    for (Int_t j=1 ; j<=5000 ; j++) {
      Double_t logj = log((Double_t)j) ;
      for (Int_t ii=j ; ii<=5000 ; ii++) {
   _lut[ii-1] += logj ;
      }
    }
  }

  if (i<5000) {
    return _lut[i-1] ;
  } else {
    Double_t ret = _lut[4999] ;
    cout << "logSum i=" << i << endl ;
    for (Int_t j=5000 ; j<=i ; j++) {
      ret += log((Double_t)j) ;
    }
    return ret ;
  }

}