RooProdPdf.cxx

Go to the documentation of this file.

/*****************************************************************************
 * Project: RooFit                                                           *
 * Package: RooFitCore                                                       *
 * @(#)root/roofitcore:$Id$
 * Authors:                                                                  *
 *   WV, Wouter Verkerke, UC Santa Barbara, verkerke@slac.stanford.edu       *
 *   DK, David Kirkby,    UC Irvine,         dkirkby@uci.edu                 *
 *                                                                           *
 * Copyright (c) 2000-2005, Regents of the University of California          *
 *                          and Stanford University. All rights reserved.    *
 *                                                                           *
 * Redistribution and use in source and binary forms,                        *
 * with or without modification, are permitted according to the terms        *
 * listed in LICENSE (http://roofit.sourceforge.net/license.txt)             *
 *****************************************************************************/
 
/**
\file RooProdPdf.cxx
\class RooProdPdf
\ingroup Roofitcore
 
RooProdPdf is an efficient implementation of a product of PDFs of the form
\f[ \prod_{i=1}^{N} \mathrm{PDF}_i (x, \ldots) \f]
 
PDFs may share observables. If that is the case any irreducible subset
of PDFs that share observables will be normalised with explicit numeric
integration as any built-in normalisation will no longer be valid.
 
Alternatively, products using conditional PDFs can be defined, *e.g.*
 
\f[ F(x|y) \cdot G(y), \f]
 
meaning a PDF \f$ F(x) \f$ **given** \f$ y \f$ and a PDF \f$ G(y) \f$.
In this construction, \f$ F \f$ is only
normalised w.r.t \f$ x\f$, and \f$ G \f$ is normalised w.r.t \f$ y \f$. The product in this construction
is properly normalised.
 
If exactly one of the component PDFs supports extended likelihood fits, the
product will also be usable in extended mode, returning the number of expected
events from the extendable component PDF. The extendable component does not
have to appear in any specific place in the list.
**/
 
#include "RooProdPdf.h"
#include "RooRealProxy.h"
#include "RooProdGenContext.h"
#include "RooGenProdProj.h"
#include "RooProduct.h"
#include "RooNameReg.h"
#include "RooMsgService.h"
#include "RooFormulaVar.h"
#include "RooRealVar.h"
#include "RooAddition.h"
#include "RooGlobalFunc.h"
#include "RooConstVar.h"
#include "RooWorkspace.h"
#include "RooRangeBoolean.h"
#include "RooCustomizer.h"
#include "RooRealIntegral.h"
#include "RooTrace.h"
 
#include <cstring>
#include <sstream>
#include <algorithm>
 
#ifndef _WIN32
#include <strings.h>
#endif
 
 
#include "TSystem.h"
 
using namespace std;
 
ClassImp(RooProdPdf);
;
 
 
 
////////////////////////////////////////////////////////////////////////////////
/// Default constructor
 
RooProdPdf::RooProdPdf() :
  _curNormSet(0),
  _cutOff(0),
  _extendedIndex(-1),
  _useDefaultGen(kFALSE),
  _refRangeName(0),
  _selfNorm(kTRUE)
{
  // Default constructor
  TRACE_CREATE
}
 
 
 
////////////////////////////////////////////////////////////////////////////////
/// Dummy constructor
 
RooProdPdf::RooProdPdf(const char *name, const char *title, Double_t cutOff) :
  RooAbsPdf(name,title),
  _cacheMgr(this,10),
  _genCode(10),
  _cutOff(cutOff),
  _pdfList("!pdfs","List of PDFs",this),
  _extendedIndex(-1),
  _useDefaultGen(kFALSE),
  _refRangeName(0),
  _selfNorm(kTRUE)
{
  TRACE_CREATE
}
 
 
 
////////////////////////////////////////////////////////////////////////////////
/// Constructor with 2 PDFs (most frequent use case).
///
/// The optional cutOff parameter can be used as a speed optimization if
/// one or more of the PDF have sizable regions with very small values,
/// which would pull the entire product of PDFs to zero in those regions.
///
/// After each PDF multiplication, the running product is compared with
/// the cutOff parameter. If the running product is smaller than the
/// cutOff value, the product series is terminated and remaining PDFs
/// are not evaluated.
///
/// There is no magic value of the cutOff, the user should experiment
/// to find the appropriate balance between speed and precision.
/// If a cutoff is specified, the PDFs most likely to be small should
/// be put first in the product. The default cutOff value is zero.
///
 
RooProdPdf::RooProdPdf(const char *name, const char *title,
             RooAbsPdf& pdf1, RooAbsPdf& pdf2, Double_t cutOff) :
  RooAbsPdf(name,title),
  _cacheMgr(this,10),
  _genCode(10),
  _cutOff(cutOff),
  _pdfList("!pdfs","List of PDFs",this),
  _extendedIndex(-1),
  _useDefaultGen(kFALSE),
  _refRangeName(0),
  _selfNorm(kTRUE)
{
  _pdfList.add(pdf1) ;
  RooArgSet* nset1 = new RooArgSet("nset") ;
  _pdfNSetList.Add(nset1) ;
  if (pdf1.canBeExtended()) {
    _extendedIndex = _pdfList.index(&pdf1) ;
  }
 
  _pdfList.add(pdf2) ;
  RooArgSet* nset2 = new RooArgSet("nset") ;
  _pdfNSetList.Add(nset2) ;
 
  if (pdf2.canBeExtended()) {
    if (_extendedIndex>=0) {
      // Protect against multiple extended terms
      coutW(InputArguments) << "RooProdPdf::RooProdPdf(" << GetName()
             << ") multiple components with extended terms detected,"
             << " product will not be extendible." << endl ;
      _extendedIndex=-1 ;
    } else {
      _extendedIndex=_pdfList.index(&pdf2) ;
    }
  }
  TRACE_CREATE
}
 
 
 
////////////////////////////////////////////////////////////////////////////////
/// Constructor from a list of PDFs.
///
/// The optional cutOff parameter can be used as a speed optimization if
/// one or more of the PDF have sizable regions with very small values,
/// which would pull the entire product of PDFs to zero in those regions.
///
/// After each PDF multiplication, the running product is compared with
/// the cutOff parameter. If the running product is smaller than the
/// cutOff value, the product series is terminated and remaining PDFs
/// are not evaluated.
///
/// There is no magic value of the cutOff, the user should experiment
/// to find the appropriate balance between speed and precision.
/// If a cutoff is specified, the PDFs most likely to be small should
/// be put first in the product. The default cutOff value is zero.
 
RooProdPdf::RooProdPdf(const char* name, const char* title, const RooArgList& inPdfList, Double_t cutOff) :
  RooAbsPdf(name,title),
  _cacheMgr(this,10),
  _genCode(10),
  _cutOff(cutOff),
  _pdfList("!pdfs","List of PDFs",this),
  _extendedIndex(-1),
  _useDefaultGen(kFALSE),
  _refRangeName(0),
  _selfNorm(kTRUE)
{
  RooFIter iter = inPdfList.fwdIterator();
  RooAbsArg* arg ;
  Int_t numExtended(0) ;
  while((arg=(RooAbsArg*)iter.next())) {
    RooAbsPdf* pdf = dynamic_cast<RooAbsPdf*>(arg) ;
    if (!pdf) {
      coutW(InputArguments) << "RooProdPdf::RooProdPdf(" << GetName() << ") list arg "
             << arg->GetName() << " is not a PDF, ignored" << endl ;
      continue ;
    }
    _pdfList.add(*pdf) ;
 
    RooArgSet* nset = new RooArgSet("nset") ;
    _pdfNSetList.Add(nset) ;
 
    if (pdf->canBeExtended()) {
      _extendedIndex = _pdfList.index(pdf) ;
      numExtended++ ;
    }
  }
 
  // Protect against multiple extended terms
  if (numExtended>1) {
    coutW(InputArguments) << "RooProdPdf::RooProdPdf(" << GetName()
           << ") WARNING: multiple components with extended terms detected,"
           << " product will not be extendible." << endl ;
    _extendedIndex = -1 ;
  }
 
  TRACE_CREATE
}
 
 
 
////////////////////////////////////////////////////////////////////////////////
/// Constructor from named argument list
///
/// fullPdf -- Set of 'regular' PDFS that are normalized over all their observables
/// Argument                   | Description
/// ---------------------------|------------
/// Conditional(pdfSet,depSet) | Add PDF to product with condition that it<br>only be normalized over specified observables<br>any remaining observables will be conditional<br>observables
///
///
/// For example, given a PDF F(x,y) and G(y)
///
/// RooProdPdf("P","P",G,Conditional(F,x)) will construct a 2-dimensional PDF as follows:
///
/// \f[P(x,y) = \frac{G(y)}{\int_y G(y)} * \frac{F(x,y)}{\int_x G(x,y)} \f]
///
/// which is a well normalized and properly defined PDF, but different from the
///
/// \f[P'(x,y) = \frac{F(x,y)}{\int_y G(y)} / \int_x\int_y F(x,y)*G(y) \f]
///
/// In the former case the y distribution of P is identical to that of G, while
/// F only is used to determine the correlation between X and Y. In the latter
/// case the Y distribution is defined by the product of F and G.
///
/// This P(x,y) construction is analoguous to generating events from F(x,y) with
/// a prototype dataset sampled from G(y)
 
RooProdPdf::RooProdPdf(const char* name, const char* title, const RooArgSet& fullPdfSet,
             const RooCmdArg& arg1, const RooCmdArg& arg2,
             const RooCmdArg& arg3, const RooCmdArg& arg4,
             const RooCmdArg& arg5, const RooCmdArg& arg6,
             const RooCmdArg& arg7, const RooCmdArg& arg8) :
  RooAbsPdf(name,title),
  _cacheMgr(this,10),
  _genCode(10),
  _cutOff(0),
  _pdfList("!pdfs","List of PDFs",this),
  _extendedIndex(-1),
  _useDefaultGen(kFALSE),
  _refRangeName(0),
  _selfNorm(kTRUE)
{
  RooLinkedList l ;
  l.Add((TObject*)&arg1) ;  l.Add((TObject*)&arg2) ;
  l.Add((TObject*)&arg3) ;  l.Add((TObject*)&arg4) ;
  l.Add((TObject*)&arg5) ;  l.Add((TObject*)&arg6) ;
  l.Add((TObject*)&arg7) ;  l.Add((TObject*)&arg8) ;
 
  initializeFromCmdArgList(fullPdfSet,l) ;
  TRACE_CREATE
}
 
 
 
////////////////////////////////////////////////////////////////////////////////
/// Constructor from named argument list
 
RooProdPdf::RooProdPdf(const char* name, const char* title,
             const RooCmdArg& arg1, const RooCmdArg& arg2,
             const RooCmdArg& arg3, const RooCmdArg& arg4,
             const RooCmdArg& arg5, const RooCmdArg& arg6,
             const RooCmdArg& arg7, const RooCmdArg& arg8) :
  RooAbsPdf(name,title),
  _cacheMgr(this,10),
  _genCode(10),
  _cutOff(0),
  _pdfList("!pdfList","List of PDFs",this),
  _extendedIndex(-1),
  _useDefaultGen(kFALSE),
  _refRangeName(0),
  _selfNorm(kTRUE)
{
  RooLinkedList l ;
  l.Add((TObject*)&arg1) ;  l.Add((TObject*)&arg2) ;
  l.Add((TObject*)&arg3) ;  l.Add((TObject*)&arg4) ;
  l.Add((TObject*)&arg5) ;  l.Add((TObject*)&arg6) ;
  l.Add((TObject*)&arg7) ;  l.Add((TObject*)&arg8) ;
 
  initializeFromCmdArgList(RooArgSet(),l) ;
  TRACE_CREATE
}
 
 
 
////////////////////////////////////////////////////////////////////////////////
/// Internal constructor from list of named arguments
 
RooProdPdf::RooProdPdf(const char* name, const char* title, const RooArgSet& fullPdfSet, const RooLinkedList& cmdArgList) :
  RooAbsPdf(name,title),
  _cacheMgr(this,10),
  _genCode(10),
  _cutOff(0),
  _pdfList("!pdfs","List of PDFs",this),
  _extendedIndex(-1),
  _useDefaultGen(kFALSE),
  _refRangeName(0),
  _selfNorm(kTRUE)
{
  initializeFromCmdArgList(fullPdfSet, cmdArgList) ;
  TRACE_CREATE
}
 
 
 
////////////////////////////////////////////////////////////////////////////////
/// Copy constructor
 
RooProdPdf::RooProdPdf(const RooProdPdf& other, const char* name) :
  RooAbsPdf(other,name),
  _cacheMgr(other._cacheMgr,this),
  _genCode(other._genCode),
  _cutOff(other._cutOff),
  _pdfList("!pdfs",this,other._pdfList),
  _extendedIndex(other._extendedIndex),
  _useDefaultGen(other._useDefaultGen),
  _refRangeName(other._refRangeName),
  _selfNorm(other._selfNorm),
  _defNormSet(other._defNormSet)
{
  // Clone contents of normalizarion set list
  RooFIter iter = other._pdfNSetList.fwdIterator();
  RooArgSet* nset ;
  while((nset=(RooArgSet*)iter.next())) {
    RooArgSet* tmp = (RooArgSet*) nset->snapshot() ;
    tmp->setName(nset->GetName()) ;
    _pdfNSetList.Add(tmp) ;
  }
  TRACE_CREATE
}
 
 
 
////////////////////////////////////////////////////////////////////////////////
/// Initialize RooProdPdf configuration from given list of RooCmdArg configuration arguments
/// and set of 'regular' p.d.f.s in product
 
void RooProdPdf::initializeFromCmdArgList(const RooArgSet& fullPdfSet, const RooLinkedList& l)
{
  Int_t numExtended(0) ;
 
  // Process set of full PDFS
  RooFIter siter = fullPdfSet.fwdIterator() ;
  RooAbsPdf* pdf ;
  while((pdf=(RooAbsPdf*)siter.next())) {
    _pdfList.add(*pdf) ;
    RooArgSet* nset1 = new RooArgSet("nset") ;
    _pdfNSetList.Add(nset1) ;
 
    if (pdf->canBeExtended()) {
      _extendedIndex = _pdfList.index(pdf) ;
      numExtended++ ;
    }
 
  }
 
  // Process list of conditional PDFs
  RooFIter iter = l.fwdIterator();
  RooCmdArg* carg ;
  while((carg=(RooCmdArg*)iter.next())) {
 
    if (0 == strcmp(carg->GetName(), "Conditional")) {
 
      Int_t argType = carg->getInt(0) ;
      RooArgSet* pdfSet = (RooArgSet*) carg->getSet(0) ;
      RooArgSet* normSet = (RooArgSet*) carg->getSet(1) ;
 
      RooFIter siter2 = pdfSet->fwdIterator() ;
      RooAbsPdf* thePdf ;
      while ((thePdf=(RooAbsPdf*)siter2.next())) {
   _pdfList.add(*thePdf) ;
 
   RooArgSet* tmp = (RooArgSet*) normSet->snapshot() ;
   tmp->setName(0 == argType ? "nset" : "cset") ;
   _pdfNSetList.Add(tmp) ;
 
   if (thePdf->canBeExtended()) {
     _extendedIndex = _pdfList.index(thePdf) ;
     numExtended++ ;
   }
 
      }
 
    } else if (0 != strlen(carg->GetName())) {
      coutW(InputArguments) << "Unknown arg: " << carg->GetName() << endl ;
    }
  }
 
  // Protect against multiple extended terms
  if (numExtended>1) {
    coutW(InputArguments) << "RooProdPdf::RooProdPdf(" << GetName()
           << ") WARNING: multiple components with extended terms detected,"
           << " product will not be extendible." << endl ;
    _extendedIndex = -1 ;
  }
 
 
}
 
 
 
////////////////////////////////////////////////////////////////////////////////
/// Destructor
 
RooProdPdf::~RooProdPdf()
{
  _pdfNSetList.Delete() ;
  TRACE_DESTROY
}
 
 
 
////////////////////////////////////////////////////////////////////////////////
/// Overload getVal() to intercept normalization set for use in evaluate()
 
Double_t RooProdPdf::getValV(const RooArgSet* set) const
{
  _curNormSet = (RooArgSet*)set ;
  return RooAbsPdf::getValV(set) ;
}
 
 
 
////////////////////////////////////////////////////////////////////////////////
/// Calculate current value of object
 
Double_t RooProdPdf::evaluate() const
{
  Int_t code ;
  CacheElem* cache = (CacheElem*) _cacheMgr.getObj(_curNormSet,0,&code) ;
 
  // If cache doesn't have our configuration, recalculate here
  if (!cache) {
    code = getPartIntList(_curNormSet, nullptr) ;
    cache = (CacheElem*) _cacheMgr.getObj(_curNormSet,0,&code) ;
  }
 
 
  return calculate(*cache) ;
}
 
 
 
////////////////////////////////////////////////////////////////////////////////
/// Calculate running product of pdfs terms, using the supplied
/// normalization set in 'normSetList' for each component
 
Double_t RooProdPdf::calculate(const RooArgList* partIntList, const RooLinkedList* normSetList) const
{
  RooAbsReal* partInt;
  RooArgSet* normSet;
  Double_t value = 1.0;
  RooFIter plIter = partIntList->fwdIterator(), nlIter = normSetList->fwdIterator();
 
    for (partInt = (RooAbsReal*) plIter.next(),
   normSet = (RooArgSet*) nlIter.next(); partInt && normSet;
      partInt = (RooAbsReal*) plIter.next(),
      normSet = (RooArgSet*) nlIter.next()) {
    const Double_t piVal = partInt->getVal(normSet->getSize() > 0 ? normSet : 0);
//  cout << "RooProdPdf::calculate(" << GetName() << ") partInt(" << partInt->GetName() << ") = " << piVal << " normSet = " << normSet << " " << (normSet->getSize()>0 ? *normSet : RooArgSet()) << endl ;
    value *= piVal;
    if (value <= _cutOff) { break; }
  }
 
  return value ;
}
 
 
 
////////////////////////////////////////////////////////////////////////////////
/// Calculate running product of pdfs terms, using the supplied
/// normalization set in 'normSetList' for each component
 
Double_t RooProdPdf::calculate(const RooProdPdf::CacheElem& cache, Bool_t /*verbose*/) const
{
  //cout << "RooProdPdf::calculate from cache" << endl ;
 
  if (cache._isRearranged) {
    if (dologD(Eval)) {
      cxcoutD(Eval) << "RooProdPdf::calculate(" << GetName() << ") rearranged product calculation"
                    << " calculate: num = " << cache._rearrangedNum->GetName() << " = " << cache._rearrangedNum->getVal() << endl ;
//       cache._rearrangedNum->printComponentTree("",0,5) ;
      cxcoutD(Eval) << "calculate: den = " << cache._rearrangedDen->GetName() << " = " << cache._rearrangedDen->getVal() << endl ;
//       cache._rearrangedDen->printComponentTree("",0,5) ;
    }
 
    return cache._rearrangedNum->getVal() / cache._rearrangedDen->getVal();
  } else {
 
    Double_t value = 1.0;
    assert(cache._normList.size() == cache._partList.size());
    for (std::size_t i = 0; i < cache._partList.size(); ++i) {
      const auto& partInt = static_cast<const RooAbsReal&>(cache._partList[i]);
      const auto normSet = cache._normList[i].get();
 
      const Double_t piVal = partInt.getVal(normSet->getSize() > 0 ? normSet : nullptr);
      value *= piVal ;
      if (value <= _cutOff) break;
    }
//   cout << "return value = " << value << endl ;
    return value ;
  }
}
 
 
 
////////////////////////////////////////////////////////////////////////////////
/// Factorize product in irreducible terms for given choice of integration/normalization
 
void RooProdPdf::factorizeProduct(const RooArgSet& normSet, const RooArgSet& intSet,
              RooLinkedList& termList, RooLinkedList& normList,
              RooLinkedList& impDepList, RooLinkedList& crossDepList,
              RooLinkedList& intList) const
{
  // List of all term dependents: normalization and imported
  RooLinkedList depAllList;
  RooLinkedList depIntNoNormList;
 
  // Setup lists for factorization terms and their dependents
  RooArgSet* term(0);
  RooArgSet* termNormDeps(0);
  RooArgSet* termAllDeps(0);
  RooArgSet* termIntDeps(0);
  RooArgSet* termIntNoNormDeps(0);
 
  // Loop over the PDFs
  RooAbsPdf* pdf;
  RooArgSet* pdfNSetOrig;
  for (RooFIter pdfIter = _pdfList.fwdIterator(),
      nIter = _pdfNSetList.fwdIterator();
      (pdfNSetOrig = (RooArgSet*) nIter.next(),
       pdf = (RooAbsPdf*) pdfIter.next()); ) {
    RooArgSet* pdfNSet, *pdfCSet;
 
    // Reduce pdfNSet to actual dependents
    if (0 == strcmp("nset", pdfNSetOrig->GetName())) {
      pdfNSet = pdf->getObservables(*pdfNSetOrig);
      pdfCSet = new RooArgSet;
    } else if (0 == strcmp("cset", pdfNSetOrig->GetName())) {
      RooArgSet* tmp = pdf->getObservables(normSet);
      tmp->remove(*pdfNSetOrig, kTRUE, kTRUE);
      pdfCSet = pdfNSetOrig;
      pdfNSet = tmp;
    } else {
      // Legacy mode. Interpret at NSet for backward compatibility
      pdfNSet = pdf->getObservables(*pdfNSetOrig);
      pdfCSet = new RooArgSet;
    }
 
 
    RooArgSet pdfNormDeps; // Dependents to be normalized for the PDF
    RooArgSet pdfAllDeps; // All dependents of this PDF
 
    // Make list of all dependents of this PDF
    RooArgSet* tmp = pdf->getObservables(normSet);
    pdfAllDeps.add(*tmp);
    delete tmp;
 
 
//     cout << GetName() << ": pdf = " << pdf->GetName() << " pdfAllDeps = " << pdfAllDeps << " pdfNSet = " << *pdfNSet << " pdfCSet = " << *pdfCSet << endl;
 
    // Make list of normalization dependents for this PDF;
    if (pdfNSet->getSize() > 0) {
      // PDF is conditional
      RooArgSet* tmp2 = (RooArgSet*) pdfAllDeps.selectCommon(*pdfNSet);
      pdfNormDeps.add(*tmp2);
      delete tmp2;
    } else {
      // PDF is regular
      pdfNormDeps.add(pdfAllDeps);
    }
 
//     cout << GetName() << ": pdfNormDeps for " << pdf->GetName() << " = " << pdfNormDeps << endl;
 
    RooArgSet* pdfIntSet = pdf->getObservables(intSet) ;
 
    // WVE if we have no norm deps, conditional observables should be taken out of pdfIntSet
    if (0 == pdfNormDeps.getSize() && pdfCSet->getSize() > 0) {
      pdfIntSet->remove(*pdfCSet, kTRUE, kTRUE);
//       cout << GetName() << ": have no norm deps, removing conditional observables from intset" << endl;
    }
 
    RooArgSet pdfIntNoNormDeps(*pdfIntSet);
    pdfIntNoNormDeps.remove(pdfNormDeps, kTRUE, kTRUE);
 
//     cout << GetName() << ": pdf = " << pdf->GetName() << " intset = " << *pdfIntSet << " pdfIntNoNormDeps = " << pdfIntNoNormDeps << endl;
 
    // Check if this PDF has dependents overlapping with one of the existing terms
    Bool_t done(kFALSE);
    for (RooFIter lIter = termList.fwdIterator(),
   ldIter = normList.fwdIterator(),
   laIter = depAllList.fwdIterator();
      (termNormDeps = (RooArgSet*) ldIter.next(),
       termAllDeps = (RooArgSet*) laIter.next(),
       term = (RooArgSet*) lIter.next()); ) {
      // PDF should be added to existing term if
      // 1) It has overlapping normalization dependents with any other PDF in existing term
      // 2) It has overlapping dependents of any class for which integration is requested
      // 3) If normalization happens over multiple ranges, and those ranges are both defined
      //    in either observable
 
      Bool_t normOverlap = pdfNormDeps.overlaps(*termNormDeps);
      //Bool_t intOverlap =  pdfIntSet->overlaps(*termAllDeps);
 
      if (normOverlap) {
//    cout << GetName() << ": this term overlaps with term " << (*term) << " in normalization observables" << endl;
 
   term->add(*pdf);
   termNormDeps->add(pdfNormDeps, kFALSE);
   termAllDeps->add(pdfAllDeps, kFALSE);
   if (!termIntDeps) {
     termIntDeps = new RooArgSet("termIntDeps");
   }
   termIntDeps->add(*pdfIntSet, kFALSE);
   if (!termIntNoNormDeps) {
     termIntNoNormDeps = new RooArgSet("termIntNoNormDeps");
   }
   termIntNoNormDeps->add(pdfIntNoNormDeps, kFALSE);
   done = kTRUE;
      }
    }
 
    // If not, create a new term
    if (!done) {
      if (!(0 == pdfNormDeps.getSize() && 0 == pdfAllDeps.getSize() &&
       0 == pdfIntSet->getSize()) || 0 == normSet.getSize()) {
//    cout << GetName() << ": creating new term" << endl;
   term = new RooArgSet("term");
   termNormDeps = new RooArgSet("termNormDeps");
   termAllDeps = new RooArgSet("termAllDeps");
   termIntDeps = new RooArgSet("termIntDeps");
   termIntNoNormDeps = new RooArgSet("termIntNoNormDeps");
 
   term->add(*pdf);
   termNormDeps->add(pdfNormDeps, kFALSE);
   termAllDeps->add(pdfAllDeps, kFALSE);
   termIntDeps->add(*pdfIntSet, kFALSE);
   termIntNoNormDeps->add(pdfIntNoNormDeps, kFALSE);
 
   termList.Add(term);
   normList.Add(termNormDeps);
   depAllList.Add(termAllDeps);
   intList.Add(termIntDeps);
   depIntNoNormList.Add(termIntNoNormDeps);
      }
    }
 
    // We own the reduced version of pdfNSet
    delete pdfNSet;
    delete pdfIntSet;
    if (pdfCSet != pdfNSetOrig) {
      delete pdfCSet;
    }
  }
 
  // Loop over list of terms again to determine 'imported' observables
  RooArgSet *normDeps, *allDeps, *intNoNormDeps;
  for (RooFIter lIter = termList.fwdIterator(),
      ldIter = normList.fwdIterator(),
      laIter = depAllList.fwdIterator(),
      innIter = depIntNoNormList.fwdIterator();
      (normDeps = (RooArgSet*) ldIter.next(),
       allDeps = (RooArgSet*) laIter.next(),
       intNoNormDeps = (RooArgSet*) innIter.next(),
       term=(RooArgSet*)lIter.next()); ) {
    // Make list of wholly imported dependents
    RooArgSet impDeps(*allDeps);
    impDeps.remove(*normDeps, kTRUE, kTRUE);
    impDepList.Add(impDeps.snapshot());
//     cout << GetName() << ": list of imported dependents for term " << (*term) << " set to " << impDeps << endl ;
 
    // Make list of cross dependents (term is self contained for these dependents,
    // but components import dependents from other components)
    RooArgSet* crossDeps = (RooArgSet*) intNoNormDeps->selectCommon(*normDeps);
    crossDepList.Add(crossDeps->snapshot());
//     cout << GetName() << ": list of cross dependents for term " << (*term) << " set to " << *crossDeps << endl ;
    delete crossDeps;
  }
 
  depAllList.Delete();
  depIntNoNormList.Delete();
 
  return;
}
 
 
 
 
////////////////////////////////////////////////////////////////////////////////
/// Return list of (partial) integrals of product terms for integration
/// of p.d.f over observables iset while normalization over observables nset.
/// Also return list of normalization sets to be used to evaluate
/// each component in the list correctly.
 
Int_t RooProdPdf::getPartIntList(const RooArgSet* nset, const RooArgSet* iset, const char* isetRangeName) const
{
//    cout << "   FOLKERT::RooProdPdf::getPartIntList(" << GetName() <<")  nset = " << (nset?*nset:RooArgSet()) << endl
//         << "   _normRange = " << _normRange << endl
//         << "   iset = " << (iset?*iset:RooArgSet()) << endl
//         << "   isetRangeName = " << (isetRangeName?isetRangeName:"<null>") << endl ;
 
  // Check if this configuration was created before
  Int_t sterileIdx(-1);
 
  CacheElem* cache = (CacheElem*) _cacheMgr.getObj(nset,iset,&sterileIdx,isetRangeName);
  if (cache) {
    return _cacheMgr.lastIndex();
  }
 
  // Create containers for partial integral components to be generated
  cache = new CacheElem;
 
  // Factorize the product in irreducible terms for this nset
  RooLinkedList terms, norms, imp, ints, cross;
//   cout << "RooProdPdf::getPIL -- now calling factorizeProduct()" << endl ;
 
 
  // Normalization set used for factorization
  RooArgSet factNset(nset ? (*nset) : _defNormSet);
//   cout << GetName() << "factNset = " << factNset << endl ;
 
  factorizeProduct(factNset, iset ? (*iset) : RooArgSet(), terms, norms, imp, cross, ints);
 
  RooArgSet *norm, *integ, *xdeps, *imps;
 
  // Group irriducible terms that need to be (partially) integrated together
  RooLinkedList groupedList;
  RooArgSet outerIntDeps;
//   cout << "RooProdPdf::getPIL -- now calling groupProductTerms()" << endl;
  groupProductTerms(groupedList, outerIntDeps, terms, norms, imp, ints, cross);
  RooFIter gIter = groupedList.fwdIterator();
  RooLinkedList* group;
 
  // Loop over groups
//   cout<<"FK: pdf("<<GetName()<<") Starting selecting F(x|y)!"<<endl;
  // Find groups of type F(x|y), i.e. termImpSet!=0, construct ratio object
  map<string, RooArgSet> ratioTerms;
  while ((group = (RooLinkedList*) gIter.next())) {
    if (1 == group->GetSize()) {
//       cout<<"FK: Starting Single Term"<<endl;
 
      RooArgSet* term = (RooArgSet*) group->At(0);
 
      Int_t termIdx = terms.IndexOf(term);
      norm=(RooArgSet*) norms.At(termIdx);
      imps=(RooArgSet*)imp.At(termIdx);
      RooArgSet termNSet(*norm), termImpSet(*imps);
 
//       cout<<"FK: termImpSet.getSize()  = "<<termImpSet.getSize()<< " " << termImpSet << endl;
//       cout<<"FK: _refRangeName = "<<_refRangeName<<endl;
 
      if (termImpSet.getSize() > 0 && 0 != _refRangeName) {
 
//    cout << "WVE now here" << endl;
 
   // WVE we can skip this if the ref range is equal to the normalization range
   Bool_t rangeIdentical(kTRUE);
   RooFIter niter = termNSet.fwdIterator();
   RooRealVar* normObs;
//    cout << "_normRange = " << _normRange << " _refRangeName = " << RooNameReg::str(_refRangeName) << endl ;
   while ((normObs = (RooRealVar*) niter.next())) {
     //FK: Here the refRange should be compared to _normRange, if it's set, and to the normObs range if it's not set
     if (_normRange.Length() > 0) {
       if (normObs->getMin(_normRange.Data()) != normObs->getMin(RooNameReg::str(_refRangeName))) rangeIdentical = kFALSE;
       if (normObs->getMax(_normRange.Data()) != normObs->getMax(RooNameReg::str(_refRangeName))) rangeIdentical = kFALSE;
     }
     else{
       if (normObs->getMin() != normObs->getMin(RooNameReg::str(_refRangeName))) rangeIdentical = kFALSE;
       if (normObs->getMax() != normObs->getMax(RooNameReg::str(_refRangeName))) rangeIdentical = kFALSE;
     }
   }
//    cout<<"FK: rangeIdentical Single = "<<(rangeIdentical ? 'T':'F')<<endl;
   // coverity[CONSTANT_EXPRESSION_RESULT]
   if (!rangeIdentical || 1) {
//      cout << "PREPARING RATIO HERE (SINGLE TERM)" << endl ;
     RooAbsReal* ratio = makeCondPdfRatioCorr(*(RooAbsReal*)term->first(), termNSet, termImpSet, normRange(), RooNameReg::str(_refRangeName));
     ostringstream str; termImpSet.printValue(str);
//      cout << GetName() << "inserting ratio term" << endl;
     ratioTerms[str.str()].add(*ratio);
   }
      }
 
    } else {
//       cout<<"FK: Starting Composite Term"<<endl;
 
      RooArgSet compTermSet, compTermNorm;
      RooFIter tIter = group->fwdIterator();
      RooArgSet* term;
      while ((term = (RooArgSet*) tIter.next())) {
 
   Int_t termIdx = terms.IndexOf(term);
   norm=(RooArgSet*) norms.At(termIdx);
   imps=(RooArgSet*)imp.At(termIdx);
   RooArgSet termNSet(*norm), termImpSet(*imps);
 
   if (termImpSet.getSize() > 0 && 0 != _refRangeName) {
 
     // WVE we can skip this if the ref range is equal to the normalization range
     Bool_t rangeIdentical(kTRUE);
     RooFIter niter = termNSet.fwdIterator();
     RooRealVar* normObs;
     //FK: Here the refRange should be compared to _normRange, if it's set, and to the normObs range if it's not set
     if(_normRange.Length() > 0) {
       while ((normObs = (RooRealVar*) niter.next())) {
         if (normObs->getMin(_normRange.Data()) != normObs->getMin(RooNameReg::str(_refRangeName))) rangeIdentical = kFALSE;
         if (normObs->getMax(_normRange.Data()) != normObs->getMax(RooNameReg::str(_refRangeName))) rangeIdentical = kFALSE;
       }
     } else {
       while ((normObs = (RooRealVar*) niter.next())) {
         if (normObs->getMin() != normObs->getMin(RooNameReg::str(_refRangeName))) rangeIdentical = kFALSE;
         if (normObs->getMax() != normObs->getMax(RooNameReg::str(_refRangeName))) rangeIdentical = kFALSE;
       }
     }
//      cout<<"FK: rangeIdentical Composite = "<<(rangeIdentical ? 'T':'F') <<endl;
     if (!rangeIdentical || 1) {
//        cout << "PREPARING RATIO HERE (COMPOSITE TERM)" << endl ;
       RooAbsReal* ratio = makeCondPdfRatioCorr(*(RooAbsReal*)term->first(), termNSet, termImpSet, normRange(), RooNameReg::str(_refRangeName));
       ostringstream str; termImpSet.printValue(str);
       ratioTerms[str.str()].add(*ratio);
     }
   }
      }
    }
 
  }
 
  // Find groups with y as termNSet
  // Replace G(y) with (G(y),ratio)
  gIter = groupedList.fwdIterator();
  while ((group = (RooLinkedList*) gIter.next())) {
    if (1 == group->GetSize()) {
      RooArgSet* term = (RooArgSet*) group->At(0);
 
      Int_t termIdx = terms.IndexOf(term);
      norm = (RooArgSet*) norms.At(termIdx);
      imps = (RooArgSet*) imp.At(termIdx);
      RooArgSet termNSet(*norm), termImpSet(*imps);
 
      // If termNset matches index of ratioTerms, insert ratio here
      ostringstream str; termNSet.printValue(str);
      if (ratioTerms[str.str()].getSize() > 0) {
//    cout << "MUST INSERT RATIO OBJECT IN TERM (SINGLE) " << *term << endl;
   term->add(ratioTerms[str.str()]);
      }
    } else {
      RooArgSet compTermSet, compTermNorm;
      RooFIter tIter = group->fwdIterator();
      RooArgSet* term;
      while ((term = (RooArgSet*) tIter.next())) {
   Int_t termIdx = terms.IndexOf(term);
   norm = (RooArgSet*) norms.At(termIdx);
   imps = (RooArgSet*) imp.At(termIdx);
   RooArgSet termNSet(*norm), termImpSet(*imps);
 
   // If termNset matches index of ratioTerms, insert ratio here
   ostringstream str; termNSet.printValue(str);
   if (ratioTerms[str.str()].getSize() > 0) {
//      cout << "MUST INSERT RATIO OBJECT IN TERM (COMPOSITE)" << *term << endl;
     term->add(ratioTerms[str.str()]);
   }
      }
    }
  }
 
  gIter = groupedList.fwdIterator();
  while ((group = (RooLinkedList*) gIter.next())) {
//     cout << GetName() << ":now processing group" << endl;
//      group->Print("1");
 
    if (1 == group->GetSize()) {
//       cout << "processing atomic item" << endl;
      RooArgSet* term = (RooArgSet*) group->At(0);
 
      Int_t termIdx = terms.IndexOf(term);
      norm = (RooArgSet*) norms.At(termIdx);
      integ = (RooArgSet*) ints.At(termIdx);
      xdeps = (RooArgSet*) cross.At(termIdx);
      imps = (RooArgSet*) imp.At(termIdx);
 
      RooArgSet termNSet, termISet, termXSet, termImpSet;
 
      // Take list of normalization, integrated dependents from factorization algorithm
      termISet.add(*integ);
      termNSet.add(*norm);
 
      // Cross-imported integrated dependents
      termXSet.add(*xdeps);
      termImpSet.add(*imps);
 
//       cout << GetName() << ": termISet = " << termISet << endl;
//       cout << GetName() << ": termNSet = " << termNSet << endl;
//       cout << GetName() << ": termXSet = " << termXSet << endl;
//       cout << GetName() << ": termImpSet = " << termImpSet << endl;
 
      // Add prefab term to partIntList.
      Bool_t isOwned(kFALSE);
      vector<RooAbsReal*> func = processProductTerm(nset, iset, isetRangeName, term, termNSet, termISet, isOwned);
      if (func[0]) {
   cache->_partList.add(*func[0]);
   if (isOwned) cache->_ownedList.addOwned(*func[0]);
 
   cache->_normList.emplace_back(norm->snapshot(kFALSE));
 
   cache->_numList.addOwned(*func[1]);
   cache->_denList.addOwned(*func[2]);
//    cout << "func[0]=" << func[0]->IsA()->GetName() << "::" << func[0]->GetName() << endl;
//    cout << "func[1]=" << func[1]->IsA()->GetName() << "::" << func[1]->GetName() << endl;
//    cout << "func[2]=" << func[2]->IsA()->GetName() << "::" << func[2]->GetName() << endl;
      }
    } else {
//        cout << "processing composite item" << endl;
      RooArgSet compTermSet, compTermNorm, compTermNum, compTermDen;
      RooFIter tIter = group->fwdIterator();
      RooArgSet* term;
      while ((term = (RooArgSet*) tIter.next())) {
//    cout << GetName() << ": processing term " << (*term) << " of composite item" << endl ;
   Int_t termIdx = terms.IndexOf(term);
   norm = (RooArgSet*) norms.At(termIdx);
   integ = (RooArgSet*) ints.At(termIdx);
   xdeps = (RooArgSet*) cross.At(termIdx);
   imps = (RooArgSet*) imp.At(termIdx);
 
   RooArgSet termNSet, termISet, termXSet, termImpSet;
   termISet.add(*integ);
   termNSet.add(*norm);
   termXSet.add(*xdeps);
   termImpSet.add(*imps);
 
   // Remove outer integration dependents from termISet
   termISet.remove(outerIntDeps, kTRUE, kTRUE);
//       cout << "termISet = "; termISet.Print("1");
 
//    cout << GetName() << ": termISet = " << termISet << endl;
//    cout << GetName() << ": termNSet = " << termNSet << endl;
//    cout << GetName() << ": termXSet = " << termXSet << endl;
//    cout << GetName() << ": termImpSet = " << termImpSet << endl;
 
   Bool_t isOwned = false;
   vector<RooAbsReal*> func = processProductTerm(nset, iset, isetRangeName, term, termNSet, termISet, isOwned, kTRUE);
//       cout << GetName() << ": created composite term component " << func[0]->GetName() << endl;
   if (func[0]) {
     compTermSet.add(*func[0]);
     if (isOwned) cache->_ownedList.addOwned(*func[0]);
     compTermNorm.add(*norm, kFALSE);
 
     compTermNum.add(*func[1]);
     compTermDen.add(*func[2]);
     //cache->_numList.add(*func[1]);
     //cache->_denList.add(*func[2]);
 
//      cout << "func[0]=" << func[0]->IsA()->GetName() << "::" << func[0]->GetName() << endl;
//      cout << "func[1]=" << func[1]->IsA()->GetName() << "::" << func[1]->GetName() << endl;
//      cout << "func[2]=" << func[2]->IsA()->GetName() << "::" << func[2]->GetName() << endl;
   }
      }
 
//       cout << GetName() << ": constructing special composite product" << endl;
//       cout << GetName() << ": compTermSet = " ; compTermSet.Print("1");
 
      // WVE THIS NEEDS TO BE REARRANGED
 
      // compTermset is set van partial integrals to be multiplied
      // prodtmp = product (compTermSet)
      // inttmp = int ( prodtmp ) d (outerIntDeps) _range_isetRangeName
 
      const std::string prodname = makeRGPPName("SPECPROD", compTermSet, outerIntDeps, RooArgSet(), isetRangeName);
      RooProduct* prodtmp = new RooProduct(prodname.c_str(), prodname.c_str(), compTermSet);
      cache->_ownedList.addOwned(*prodtmp);
 
      const std::string intname = makeRGPPName("SPECINT", compTermSet, outerIntDeps, RooArgSet(), isetRangeName);
      RooRealIntegral* inttmp = new RooRealIntegral(intname.c_str(), intname.c_str(), *prodtmp, outerIntDeps, 0, 0, isetRangeName);
      inttmp->setStringAttribute("PROD_TERM_TYPE", "SPECINT");
 
      cache->_ownedList.addOwned(*inttmp);
      cache->_partList.add(*inttmp);
 
      // Product of numerator terms
      const string prodname_num = makeRGPPName("SPECPROD_NUM", compTermNum, RooArgSet(), RooArgSet(), 0);
      RooProduct* prodtmp_num = new RooProduct(prodname_num.c_str(), prodname_num.c_str(), compTermNum);
      prodtmp_num->addOwnedComponents(compTermNum);
      cache->_ownedList.addOwned(*prodtmp_num);
 
      // Product of denominator terms
      const string prodname_den = makeRGPPName("SPECPROD_DEN", compTermDen, RooArgSet(), RooArgSet(), 0);
      RooProduct* prodtmp_den = new RooProduct(prodname_den.c_str(), prodname_den.c_str(), compTermDen);
      prodtmp_den->addOwnedComponents(compTermDen);
      cache->_ownedList.addOwned(*prodtmp_den);
 
      // Ratio
      string name = Form("SPEC_RATIO(%s,%s)", prodname_num.c_str(), prodname_den.c_str());
      RooFormulaVar* ndr = new RooFormulaVar(name.c_str(), "@0/@1", RooArgList(*prodtmp_num, *prodtmp_den));
 
      // Integral of ratio
      RooAbsReal* numtmp = ndr->createIntegral(outerIntDeps,isetRangeName);
      numtmp->addOwnedComponents(*ndr);
 
      cache->_numList.addOwned(*numtmp);
      cache->_denList.addOwned(*(RooAbsArg*)RooFit::RooConst(1).clone("1"));
      cache->_normList.emplace_back(compTermNorm.snapshot(kFALSE));
    }
  }
 
  // Store the partial integral list and return the assigned code
  Int_t returnCode = _cacheMgr.setObj(nset, iset, (RooAbsCacheElement*)cache, RooNameReg::ptr(isetRangeName));
 
  // WVE DEBUG PRINTING
//   cout << "RooProdPdf::getPartIntList(" << GetName() << ") made cache " << cache << " with the following nset pointers ";
//   TIterator* nliter = nsetList->MakeIterator();
//   RooArgSet* ns;
//   while((ns=(RooArgSet*)nliter->Next())) {
//     cout << ns << " ";
//   }
//   cout << endl;
//   delete nliter;
 
//   cout << "   FOLKERT::RooProdPdf::getPartIntList END(" << GetName() <<")  nset = " << (nset?*nset:RooArgSet()) << endl
//        << "   _normRange = " << _normRange << endl
//        << "   iset = " << (iset?*iset:RooArgSet()) << endl
//        << "   partList = ";
//   if(partListPointer) partListPointer->Print();
//   cout << "   nsetList = ";
//   if(nsetListPointer) nsetListPointer->Print("");
//   cout << "   code = " << returnCode << endl
//        << "   isetRangeName = " << (isetRangeName?isetRangeName:"<null>") << endl;
 
 
  // Need to rearrange product in case of multiple ranges
  if (_normRange.Contains(",")) {
    rearrangeProduct(*cache);
  }
 
  // We own contents of all lists filled by factorizeProduct()
  groupedList.Delete();
  terms.Delete();
  ints.Delete();
  imp.Delete();
  norms.Delete();
  cross.Delete();
 
  return returnCode;
}
 
 
 
 
////////////////////////////////////////////////////////////////////////////////
/// For single normalization ranges
 
RooAbsReal* RooProdPdf::makeCondPdfRatioCorr(RooAbsReal& pdf, const RooArgSet& termNset, const RooArgSet& /*termImpSet*/, const char* normRangeTmp, const char* refRange) const
{
  RooAbsReal* ratio_num = pdf.createIntegral(termNset,normRangeTmp) ;
  RooAbsReal* ratio_den = pdf.createIntegral(termNset,refRange) ;
  RooFormulaVar* ratio = new RooFormulaVar(Form("ratio(%s,%s)",ratio_num->GetName(),ratio_den->GetName()),"@0/@1",
                  RooArgList(*ratio_num,*ratio_den)) ;
 
  ratio->addOwnedComponents(RooArgSet(*ratio_num,*ratio_den)) ;
  ratio->setAttribute("RATIO_TERM") ;
  return ratio ;
}
 
 
 
 
////////////////////////////////////////////////////////////////////////////////
 
void RooProdPdf::rearrangeProduct(RooProdPdf::CacheElem& cache) const
{
  RooAbsReal* part, *num, *den ;
  RooArgSet nomList ;
 
  list<string> rangeComps ;
  {
    char* buf = new char[strlen(_normRange.Data()) + 1] ;
    strcpy(buf,_normRange.Data()) ;
    char* save(0) ;
    char* token = R__STRTOK_R(buf,",",&save) ;
    while(token) {
      rangeComps.push_back(token) ;
      token = R__STRTOK_R(0,",",&save) ;
    }
    delete[] buf;
  }
 
 
  map<string,RooArgSet> denListList ;
  RooArgSet specIntDeps ;
  string specIntRange ;
 
//   cout << "THIS IS REARRANGEPRODUCT" << endl ;
 
  RooFIter iterp = cache._partList.fwdIterator() ;
  RooFIter iter1 = cache._numList.fwdIterator() ;
  RooFIter iter2 = cache._denList.fwdIterator() ;
  while((part=(RooAbsReal*)iterp.next())) {
 
    num = (RooAbsReal*) iter1.next() ;
    den = (RooAbsReal*) iter2.next() ;
 
//     cout << "now processing part " << part->GetName() << " of type " << part->getStringAttribute("PROD_TERM_TYPE") << endl ;
//     cout << "corresponding numerator = " << num->GetName() << endl ;
//     cout << "corresponding denominator = " << den->GetName() << endl ;
 
 
    RooFormulaVar* ratio(0) ;
    RooArgSet origNumTerm ;
 
    if (string("SPECINT")==part->getStringAttribute("PROD_TERM_TYPE")) {
 
   RooRealIntegral* orig = (RooRealIntegral*) num;
   RooFormulaVar* specratio = (RooFormulaVar*) &orig->integrand() ;
   RooProduct* func = (RooProduct*) specratio->getParameter(0) ;
 
   RooArgSet* comps = orig->getComponents() ;
   RooFIter iter = comps->fwdIterator() ;
   RooAbsArg* carg ;
   while((carg=(RooAbsArg*)iter.next())) {
     if (carg->getAttribute("RATIO_TERM")) {
       ratio = (RooFormulaVar*)carg ;
       break ;
     }
   }
   delete comps ;
 
   if (ratio) {
     RooCustomizer cust(*func,"blah") ;
     cust.replaceArg(*ratio,RooFit::RooConst(1)) ;
     RooAbsArg* funcCust = cust.build() ;
//      cout << "customized function = " << endl ;
//      funcCust->printComponentTree() ;
     nomList.add(*funcCust) ;
   } else {
     nomList.add(*func) ;
   }
 
 
    } else {
 
      // Find the ratio term
      RooAbsReal* func = num;
      // If top level object is integral, navigate to integrand
      if (func->InheritsFrom(RooRealIntegral::Class())) {
   func = (RooAbsReal*) &((RooRealIntegral*)(func))->integrand();
      }
      if (func->InheritsFrom(RooProduct::Class())) {
//    cout << "product term found: " ; func->Print() ;
   RooArgSet comps(((RooProduct*)(func))->components()) ;
   RooFIter iter = comps.fwdIterator() ;
   RooAbsArg* arg ;
   while((arg=(RooAbsArg*)iter.next())) {
     if (arg->getAttribute("RATIO_TERM")) {
       ratio = (RooFormulaVar*)(arg) ;
     } else {
       origNumTerm.add(*arg) ;
     }
   }
      }
 
      if (ratio) {
//    cout << "Found ratio term in numerator: " << ratio->GetName() << endl ;
//    cout << "Adding only original term to numerator: " << origNumTerm << endl ;
   nomList.add(origNumTerm) ;
      } else {
   nomList.add(*num) ;
      }
 
    }
 
    for (list<string>::iterator iter = rangeComps.begin() ; iter != rangeComps.end() ; ++iter) {
      // If denominator is an integral, make a clone with the integration range adjusted to
      // the selected component of the normalization integral
//       cout << "NOW PROCESSING DENOMINATOR " << den->IsA()->GetName() << "::" << den->GetName() << endl ;
 
      if (string("SPECINT")==part->getStringAttribute("PROD_TERM_TYPE")) {
 
//    cout << "create integral: SPECINT case" << endl ;
   RooRealIntegral* orig = (RooRealIntegral*) num;
   RooFormulaVar* specRatio = (RooFormulaVar*) &orig->integrand() ;
   specIntDeps.add(orig->intVars()) ;
   if (orig->intRange()) {
     specIntRange = orig->intRange() ;
   }
   //RooProduct* numtmp = (RooProduct*) specRatio->getParameter(0) ;
   RooProduct* dentmp = (RooProduct*) specRatio->getParameter(1) ;
 
//    cout << "numtmp = " << numtmp->IsA()->GetName() << "::" << numtmp->GetName() << endl ;
//    cout << "dentmp = " << dentmp->IsA()->GetName() << "::" << dentmp->GetName() << endl ;
 
//    cout << "denominator components are " << dentmp->components() << endl ;
   RooArgSet comps(dentmp->components()) ;
   RooFIter piter = comps.fwdIterator() ;
   RooAbsReal* parg ;
   while((parg=(RooAbsReal*)piter.next())) {
//      cout << "now processing denominator component " << parg->IsA()->GetName() << "::" << parg->GetName() << endl ;
 
     if (ratio && parg->dependsOn(*ratio)) {
//        cout << "depends in value of ratio" << endl ;
 
       // Make specialize ratio instance
       RooAbsReal* specializedRatio = specializeRatio(*(RooFormulaVar*)ratio,iter->c_str()) ;
 
//        cout << "specRatio = " << endl ;
//        specializedRatio->printComponentTree() ;
 
       // Replace generic ratio with specialized ratio
       RooAbsArg *partCust(0) ;
       if (parg->InheritsFrom(RooAddition::Class())) {
 
 
 
         RooAddition* tmpadd = (RooAddition*)(parg) ;
 
         RooCustomizer cust(*tmpadd->list1().first(),Form("blah_%s",iter->c_str())) ;
         cust.replaceArg(*ratio,*specializedRatio) ;
         partCust = cust.build() ;
 
       } else {
         RooCustomizer cust(*parg,Form("blah_%s",iter->c_str())) ;
         cust.replaceArg(*ratio,*specializedRatio) ;
         partCust = cust.build() ;
       }
 
       // Print customized denominator
//        cout << "customized function = " << endl ;
//        partCust->printComponentTree() ;
 
       RooAbsReal* specializedPartCust = specializeIntegral(*(RooAbsReal*)partCust,iter->c_str()) ;
 
       // Finally divide again by ratio
       string name = Form("%s_divided_by_ratio",specializedPartCust->GetName()) ;
       RooFormulaVar* specIntFinal = new RooFormulaVar(name.c_str(),"@0/@1",RooArgList(*specializedPartCust,*specializedRatio)) ;
 
       denListList[*iter].add(*specIntFinal) ;
     } else {
 
//        cout << "does NOT depend on value of ratio" << endl ;
//        parg->Print("t") ;
 
       denListList[*iter].add(*specializeIntegral(*parg,iter->c_str())) ;
 
     }
   }
//    cout << "end iteration over denominator components" << endl ;
      } else {
 
   if (ratio) {
 
     RooAbsReal* specRatio = specializeRatio(*(RooFormulaVar*)ratio,iter->c_str()) ;
 
     // If integral is 'Int r(y)*g(y) dy ' then divide a posteriori by r(y)
//      cout << "have ratio, orig den = " << den->GetName() << endl ;
 
     RooArgSet tmp(origNumTerm) ;
     tmp.add(*specRatio) ;
     const string pname = makeRGPPName("PROD",tmp,RooArgSet(),RooArgSet(),0) ;
     RooProduct* specDenProd = new RooProduct(pname.c_str(),pname.c_str(),tmp) ;
     RooAbsReal* specInt(0) ;
 
     if (den->InheritsFrom(RooRealIntegral::Class())) {
       specInt = specDenProd->createIntegral(((RooRealIntegral*)den)->intVars(),iter->c_str()) ;
     } else if (den->InheritsFrom(RooAddition::Class())) {
       RooAddition* orig = (RooAddition*)den ;
       RooRealIntegral* origInt = (RooRealIntegral*) orig->list1().first() ;
       specInt = specDenProd->createIntegral(origInt->intVars(),iter->c_str()) ;
     } else {
       throw string("this should not happen") ;
     }
 
     //RooAbsReal* specInt = specializeIntegral(*den,iter->c_str()) ;
     string name = Form("%s_divided_by_ratio",specInt->GetName()) ;
     RooFormulaVar* specIntFinal = new RooFormulaVar(name.c_str(),"@0/@1",RooArgList(*specInt,*specRatio)) ;
     denListList[*iter].add(*specIntFinal) ;
   } else {
     denListList[*iter].add(*specializeIntegral(*den,iter->c_str())) ;
   }
 
      }
    }
 
  }
 
  // Do not rearrage terms if numerator and denominator are effectively empty
  if (nomList.getSize()==0) {
    return ;
  }
 
  string name = Form("%s_numerator",GetName()) ;
  // WVE FIX THIS (2)
 
  RooAbsReal* numerator = new RooProduct(name.c_str(),name.c_str(),nomList) ;
 
  RooArgSet products ;
//   cout << "nomList = " << nomList << endl ;
  for (map<string,RooArgSet>::iterator iter = denListList.begin() ; iter != denListList.end() ; ++iter) {
//     cout << "denList[" << iter->first << "] = " << iter->second << endl ;
    name = Form("%s_denominator_comp_%s",GetName(),iter->first.c_str()) ;
    // WVE FIX THIS (2)
    RooProduct* prod_comp = new RooProduct(name.c_str(),name.c_str(),iter->second) ;
    products.add(*prod_comp) ;
  }
  name = Form("%s_denominator_sum",GetName()) ;
  RooAbsReal* norm = new RooAddition(name.c_str(),name.c_str(),products) ;
  norm->addOwnedComponents(products) ;
 
  if (specIntDeps.getSize()>0) {
    // Apply posterior integration required for SPECINT case
 
    string namesr = Form("SPEC_RATIO(%s,%s)",numerator->GetName(),norm->GetName()) ;
    RooFormulaVar* ndr = new RooFormulaVar(namesr.c_str(),"@0/@1",RooArgList(*numerator,*norm)) ;
 
    // Integral of ratio
    RooAbsReal* numtmp = ndr->createIntegral(specIntDeps,specIntRange.c_str()) ;
 
    numerator = numtmp ;
    norm = (RooAbsReal*) RooFit::RooConst(1).Clone() ;
  }
 
 
//   cout << "numerator" << endl ;
//   numerator->printComponentTree("",0,5) ;
//   cout << "denominator" << endl ;
//   norm->printComponentTree("",0,5) ;
 
 
  // WVE DEBUG
  //RooMsgService::instance().debugWorkspace()->import(RooArgSet(*numerator,*norm)) ;
 
  cache._rearrangedNum.reset(numerator);
  cache._rearrangedDen.reset(norm);
  cache._isRearranged = kTRUE ;
 
}
 
 
////////////////////////////////////////////////////////////////////////////////
 
RooAbsReal* RooProdPdf::specializeRatio(RooFormulaVar& input, const char* targetRangeName) const
{
  RooRealIntegral* numint = (RooRealIntegral*) input.getParameter(0) ;
  RooRealIntegral* denint = (RooRealIntegral*) input.getParameter(1) ;
 
  RooAbsReal* numint_spec = specializeIntegral(*numint,targetRangeName) ;
 
  RooAbsReal* ret =  new RooFormulaVar(Form("ratio(%s,%s)",numint_spec->GetName(),denint->GetName()),"@0/@1",RooArgList(*numint_spec,*denint)) ;
  ret->addOwnedComponents(*numint_spec) ;
 
  return ret ;
}
 
 
 
////////////////////////////////////////////////////////////////////////////////
 
RooAbsReal* RooProdPdf::specializeIntegral(RooAbsReal& input, const char* targetRangeName) const
{
  if (input.InheritsFrom(RooRealIntegral::Class())) {
 
    // If input is integral, recreate integral but override integration range to be targetRangeName
    RooRealIntegral* orig = (RooRealIntegral*)&input ;
//     cout << "creating integral: integrand =  " << orig->integrand().GetName() << " vars = " << orig->intVars() << " range = " << targetRangeName << endl ;
    return orig->integrand().createIntegral(orig->intVars(),targetRangeName) ;
 
  } else if (input.InheritsFrom(RooAddition::Class())) {
 
    // If input is sum of integrals, recreate integral from first component of set, but override integration range to be targetRangeName
    RooAddition* orig = (RooAddition*)&input ;
    RooRealIntegral* origInt = (RooRealIntegral*) orig->list1().first() ;
//     cout << "creating integral from addition: integrand =  " << origInt->integrand().GetName() << " vars = " << origInt->intVars() << " range = " << targetRangeName << endl ;
    return origInt->integrand().createIntegral(origInt->intVars(),targetRangeName) ;
 
  } else {
 
//     cout << "specializeIntegral: unknown input type " << input.IsA()->GetName() << "::" << input.GetName() << endl ;
  }
 
  return &input ;
}
 
 
////////////////////////////////////////////////////////////////////////////////
/// Group product into terms that can be calculated independently
 
void RooProdPdf::groupProductTerms(RooLinkedList& groupedTerms, RooArgSet& outerIntDeps,
               const RooLinkedList& terms, const RooLinkedList& norms,
               const RooLinkedList& imps, const RooLinkedList& ints, const RooLinkedList& /*cross*/) const
{
  // Start out with each term in its own group
  RooFIter tIter = terms.fwdIterator() ;
  RooArgSet* term ;
  while((term=(RooArgSet*)tIter.next())) {
    RooLinkedList* group = new RooLinkedList ;
    group->Add(term) ;
    groupedTerms.Add(group) ;
  }
 
  // Make list of imported dependents that occur in any term
  RooArgSet allImpDeps ;
  RooFIter iIter = imps.fwdIterator() ;
  RooArgSet *impDeps ;
  while((impDeps=(RooArgSet*)iIter.next())) {
    allImpDeps.add(*impDeps,kFALSE) ;
  }
 
  // Make list of integrated dependents that occur in any term
  RooArgSet allIntDeps ;
  iIter = ints.fwdIterator() ;
  RooArgSet *intDeps ;
  while((intDeps=(RooArgSet*)iIter.next())) {
    allIntDeps.add(*intDeps,kFALSE) ;
  }
 
  RooArgSet* tmp = (RooArgSet*) allIntDeps.selectCommon(allImpDeps) ;
  outerIntDeps.removeAll() ;
  outerIntDeps.add(*tmp) ;
  delete tmp ;
 
  // Now iteratively merge groups that should be (partially) integrated together
  RooFIter oidIter = outerIntDeps.fwdIterator() ;
  RooAbsArg* outerIntDep ;
  while ((outerIntDep =(RooAbsArg*)oidIter.next())) {
 
    // Collect groups that feature this dependent
    RooLinkedList* newGroup = 0 ;
 
    // Loop over groups
    RooLinkedList* group ;
    RooFIter glIter = groupedTerms.fwdIterator() ;
    Bool_t needMerge = kFALSE ;
    while((group=(RooLinkedList*)glIter.next())) {
 
      // See if any term in this group depends in any ay on outerDepInt
      RooArgSet* term2 ;
      RooFIter tIter2 = group->fwdIterator() ;
      while((term2=(RooArgSet*)tIter2.next())) {
 
   Int_t termIdx = terms.IndexOf(term2) ;
   RooArgSet* termNormDeps = (RooArgSet*) norms.At(termIdx) ;
   RooArgSet* termIntDeps = (RooArgSet*) ints.At(termIdx) ;
   RooArgSet* termImpDeps = (RooArgSet*) imps.At(termIdx) ;
 
   if (termNormDeps->contains(*outerIntDep) ||
       termIntDeps->contains(*outerIntDep) ||
       termImpDeps->contains(*outerIntDep)) {
     needMerge = kTRUE ;
   }
 
      }
 
      if (needMerge) {
   // Create composite group if not yet existing
   if (newGroup==0) {
     newGroup = new RooLinkedList ;
   }
 
   // Add terms of this group to new term
   tIter2 = group->fwdIterator() ;
   while((term2=(RooArgSet*)tIter2.next())) {
     newGroup->Add(term2) ;
   }
 
   // Remove this group from list and delete it (but not its contents)
   groupedTerms.Remove(group) ;
   delete group ;
      }
    }
    // If a new group has been created to merge terms dependent on current outerIntDep, add it to group list
    if (newGroup) {
      groupedTerms.Add(newGroup) ;
    }
 
  }
}
 
 
 
////////////////////////////////////////////////////////////////////////////////
/// Calculate integrals of factorized product terms over observables iset while normalized
/// to observables in nset.
 
std::vector<RooAbsReal*> RooProdPdf::processProductTerm(const RooArgSet* nset, const RooArgSet* iset, const char* isetRangeName,
                     const RooArgSet* term,const RooArgSet& termNSet, const RooArgSet& termISet,
                     Bool_t& isOwned, Bool_t forceWrap) const
{
//    cout << "   FOLKERT::RooProdPdf(" << GetName() <<") processProductTerm nset = " << (nset?*nset:RooArgSet()) << endl
//          << "   _normRange = " << _normRange << endl
//          << "   iset = " << (iset?*iset:RooArgSet()) << endl
//          << "   isetRangeName = " << (isetRangeName?isetRangeName:"<null>") << endl
//          << "   term = " << (term?*term:RooArgSet()) << endl
//          << "   termNSet = " << termNSet << endl
//          << "   termISet = " << termISet << endl
//          << "   isOwned = " << isOwned << endl
//          << "   forceWrap = " << forceWrap << endl ;
 
  vector<RooAbsReal*> ret(3) ; ret[0] = 0 ; ret[1] = 0 ; ret[2] = 0 ;
 
  // CASE I: factorizing term: term is integrated over all normalizing observables
  // -----------------------------------------------------------------------------
  // Check if all observbales of this term are integrated. If so the term cancels
  if (termNSet.getSize()>0 && termNSet.getSize()==termISet.getSize() && isetRangeName==0) {
 
 
    //cout << "processProductTerm(" << GetName() << ") case I " << endl ;
 
    // Term factorizes
    return ret ;
  }
 
  // CASE II: Dropped terms: if term is entirely unnormalized, it should be dropped
  // ------------------------------------------------------------------------------
  if (nset && termNSet.getSize()==0) {
 
    //cout << "processProductTerm(" << GetName() << ") case II " << endl ;
 
    // Drop terms that are not asked to be normalized
    return ret ;
  }
 
  if (iset && termISet.getSize()>0) {
    if (term->getSize()==1) {
 
      // CASE IIIa: Normalized and partially integrated single PDF term
      //---------------------------------------------------------------
 
      RooAbsPdf* pdf = (RooAbsPdf*) term->first() ;
 
      RooAbsReal* partInt = pdf->createIntegral(termISet,termNSet,isetRangeName) ;
      //partInt->setOperMode(operMode()) ;
      partInt->setStringAttribute("PROD_TERM_TYPE","IIIa") ;
 
      isOwned=kTRUE ;
 
      //cout << "processProductTerm(" << GetName() << ") case IIIa func = " << partInt->GetName() << endl ;
 
      ret[0] = partInt ;
 
      // Split mode results
      ret[1] = pdf->createIntegral(termISet,isetRangeName) ;
      ret[2] = pdf->createIntegral(termNSet,normRange()) ;
 
      return ret ;
 
 
    } else {
 
      // CASE IIIb: Normalized and partially integrated composite PDF term
      //---------------------------------------------------------------
 
      // Use auxiliary class RooGenProdProj to calculate this term
      const std::string name = makeRGPPName("GENPROJ_",*term,termISet,termNSet,isetRangeName) ;
      RooAbsReal* partInt = new RooGenProdProj(name.c_str(),name.c_str(),*term,termISet,termNSet,isetRangeName) ;
      partInt->setStringAttribute("PROD_TERM_TYPE","IIIb") ;
      //partInt->setOperMode(operMode()) ;
 
      //cout << "processProductTerm(" << GetName() << ") case IIIb func = " << partInt->GetName() << endl ;
 
      isOwned=kTRUE ;
      ret[0] = partInt ;
 
      const std::string name1 = makeRGPPName("PROD",*term,RooArgSet(),RooArgSet(),0) ;
 
      // WVE FIX THIS
      RooProduct* tmp_prod = new RooProduct(name1.c_str(),name1.c_str(),*term) ;
 
      ret[1] = tmp_prod->createIntegral(termISet,isetRangeName) ;
      ret[2] = tmp_prod->createIntegral(termNSet,normRange()) ;
 
      return ret ;
    }
  }
 
  // CASE IVa: Normalized non-integrated composite PDF term
  // -------------------------------------------------------
  if (nset && nset->getSize()>0 && term->getSize()>1) {
    // Composite term needs normalized integration
 
    const std::string name = makeRGPPName("GENPROJ_",*term,termISet,termNSet,isetRangeName) ;
    RooAbsReal* partInt = new RooGenProdProj(name.c_str(),name.c_str(),*term,termISet,termNSet,isetRangeName,normRange()) ;
    partInt->setExpensiveObjectCache(expensiveObjectCache()) ;
 
    partInt->setStringAttribute("PROD_TERM_TYPE","IVa") ;
    //partInt->setOperMode(operMode()) ;
 
    //cout << "processProductTerm(" << GetName() << ") case IVa func = " << partInt->GetName() << endl ;
 
    isOwned=kTRUE ;
    ret[0] = partInt ;
 
    const std::string name1 = makeRGPPName("PROD",*term,RooArgSet(),RooArgSet(),0) ;
 
    // WVE FIX THIS
    RooProduct* tmp_prod = new RooProduct(name1.c_str(),name1.c_str(),*term) ;
 
    ret[1] = tmp_prod->createIntegral(termISet,isetRangeName) ;
    ret[2] = tmp_prod->createIntegral(termNSet,normRange()) ;
 
    return ret ;
  }
 
  // CASE IVb: Normalized, non-integrated single PDF term
  // -----------------------------------------------------
  RooFIter pIter = term->fwdIterator() ;
  RooAbsPdf* pdf ;
  while((pdf=(RooAbsPdf*)pIter.next())) {
 
    if (forceWrap) {
 
      // Construct representative name of normalization wrapper
      TString name(pdf->GetName()) ;
      name.Append("_NORM[") ;
      RooFIter nIter = termNSet.fwdIterator() ;
      RooAbsArg* arg ;
      Bool_t first(kTRUE) ;
      while((arg=(RooAbsArg*)nIter.next())) {
   if (!first) {
     name.Append(",") ;
   } else {
     first=kFALSE ;
   }
   name.Append(arg->GetName()) ;
      }
      if (normRange()) {
   name.Append("|") ;
   name.Append(normRange()) ;
      }
      name.Append("]") ;
 
      RooAbsReal* partInt = new RooRealIntegral(name.Data(),name.Data(),*pdf,RooArgSet(),&termNSet) ;
      partInt->setStringAttribute("PROD_TERM_TYPE","IVb") ;
      isOwned=kTRUE ;
 
      //cout << "processProductTerm(" << GetName() << ") case IVb func = " << partInt->GetName() << endl ;
 
      ret[0] = partInt ;
 
      ret[1] = pdf->createIntegral(RooArgSet()) ;
      ret[2] = pdf->createIntegral(termNSet,normRange()) ;
 
      return ret ;
 
 
    } else {
      isOwned=kFALSE ;
 
      //cout << "processProductTerm(" << GetName() << ") case IVb func = " << pdf->GetName() << endl ;
 
 
      pdf->setStringAttribute("PROD_TERM_TYPE","IVb") ;
      ret[0] = pdf ;
 
      ret[1] = pdf->createIntegral(RooArgSet()) ;
      ret[2] = termNSet.getSize()>0 ? pdf->createIntegral(termNSet,normRange()) : ((RooAbsReal*)RooFit::RooConst(1).clone("1")) ;
      return ret  ;
    }
  }
 
  coutE(Eval) << "RooProdPdf::processProductTerm(" << GetName() << ") unidentified term!!!" << endl ;
  return ret ;
}
 
 
 
 
////////////////////////////////////////////////////////////////////////////////
/// Make an appropriate automatic name for a RooGenProdProj object in getPartIntList()
 
std::string RooProdPdf::makeRGPPName(const char* pfx, const RooArgSet& term, const RooArgSet& iset,
                 const RooArgSet& nset, const char* isetRangeName) const
{
  // Make an appropriate automatic name for a RooGenProdProj object in getPartIntList()
 
  std::ostringstream os(pfx);
  os << "[";
 
  RooFIter pIter = term.fwdIterator() ;
  // Encode component names
  Bool_t first(kTRUE) ;
  RooAbsPdf* pdf ;
  while ((pdf=(RooAbsPdf*)pIter.next())) {
    if (!first) os << "_X_";
    first = kFALSE;
    os << pdf->GetName();
  }
  os << "]" << integralNameSuffix(iset,&nset,isetRangeName,kTRUE);
 
  return os.str();
}
 
 
 
////////////////////////////////////////////////////////////////////////////////
/// Force RooRealIntegral to offer all observables for internal integration
 
Bool_t RooProdPdf::forceAnalyticalInt(const RooAbsArg& /*dep*/) const
{
  return kTRUE ;
}
 
 
 
////////////////////////////////////////////////////////////////////////////////
/// Determine which part (if any) of given integral can be performed analytically.
/// If any analytical integration is possible, return integration scenario code.
///
/// RooProdPdf implements two strategies in implementing analytical integrals
///
/// First, PDF components whose entire set of dependents are requested to be integrated
/// can be dropped from the product, as they will integrate out to 1 by construction
///
/// Second, RooProdPdf queries each remaining component PDF for its analytical integration
/// capability of the requested set ('allVars'). It finds the largest common set of variables
/// that can be integrated by all remaining components. If such a set exists, it reconfirms that
/// each component is capable of analytically integrating the common set, and combines the components
/// individual integration codes into a single integration code valid for RooProdPdf.
 
Int_t RooProdPdf::getAnalyticalIntegralWN(RooArgSet& allVars, RooArgSet& analVars,
                 const RooArgSet* normSet, const char* rangeName) const
{
  if (_forceNumInt) return 0 ;
 
  // Declare that we can analytically integrate all requested observables
  analVars.add(allVars) ;
 
  // Retrieve (or create) the required partial integral list
  Int_t code = getPartIntList(normSet,&allVars,rangeName);
 
  return code+1 ;
}
 
 
 
 
////////////////////////////////////////////////////////////////////////////////
/// Return analytical integral defined by given scenario code
 
Double_t RooProdPdf::analyticalIntegralWN(Int_t code, const RooArgSet* normSet, const char* rangeName) const
{
  // No integration scenario
  if (code==0) {
    return getVal(normSet) ;
  }
 
 
  // WVE needs adaptation for rangename feature
 
  // Partial integration scenarios
  CacheElem* cache = (CacheElem*) _cacheMgr.getObjByIndex(code-1) ;
 
  // If cache has been sterilized, revive this slot
  if (cache==0) {
    RooArgSet* vars = getParameters(RooArgSet()) ;
    RooArgSet* nset = _cacheMgr.nameSet1ByIndex(code-1)->select(*vars) ;
    RooArgSet* iset = _cacheMgr.nameSet2ByIndex(code-1)->select(*vars) ;
 
    Int_t code2 = getPartIntList(nset, iset, rangeName) ;
 
    delete vars ;
 
    // preceding call to getPartIntList guarantees non-null return
    // coverity[NULL_RETURNS]
    cache = (CacheElem*) _cacheMgr.getObj(nset,iset,&code2,rangeName) ;
 
    delete nset ;
    delete iset ;
 
  }
 
  Double_t val = calculate(*cache,kTRUE) ;
//   cout << "RPP::aIWN(" << GetName() << ") ,code = " << code << ", value = " << val << endl ;
 
  return val ;
}
 
 
 
////////////////////////////////////////////////////////////////////////////////
/// Obsolete
 
Bool_t RooProdPdf::checkObservables(const RooArgSet* /*nset*/) const
{ return kFALSE ; }
 
 
 
 
////////////////////////////////////////////////////////////////////////////////
/// If this product contains exactly one extendable p.d.f return the extension abilities of
/// that p.d.f, otherwise return CanNotBeExtended
 
RooAbsPdf::ExtendMode RooProdPdf::extendMode() const
{
  return (_extendedIndex>=0) ? ((RooAbsPdf*)_pdfList.at(_extendedIndex))->extendMode() : CanNotBeExtended ;
}
 
 
 
////////////////////////////////////////////////////////////////////////////////
/// Return the expected number of events associated with the extentable input p.d.f
/// in the product. If there is no extendable term, return zero and issue and error
 
Double_t RooProdPdf::expectedEvents(const RooArgSet* nset) const
{
  if (_extendedIndex<0) {
    coutE(Generation) << "ERROR: Requesting expected number of events from a RooProdPdf that does not contain an extended p.d.f" << endl ;
  }
  assert(_extendedIndex>=0) ;
  return ((RooAbsPdf*)_pdfList.at(_extendedIndex))->expectedEvents(nset) ;
}
 
 
 
////////////////////////////////////////////////////////////////////////////////
/// Return generator context optimized for generating events from product p.d.f.s
 
RooAbsGenContext* RooProdPdf::genContext(const RooArgSet &vars, const RooDataSet *prototype,
                const RooArgSet* auxProto, Bool_t verbose) const
{
  if (_useDefaultGen) return RooAbsPdf::genContext(vars,prototype,auxProto,verbose) ;
  return new RooProdGenContext(*this,vars,prototype,auxProto,verbose) ;
}
 
 
 
////////////////////////////////////////////////////////////////////////////////
/// Query internal generation capabilities of component p.d.f.s and aggregate capabilities
/// into master configuration passed to the generator context
 
Int_t RooProdPdf::getGenerator(const RooArgSet& directVars, RooArgSet &generateVars, Bool_t staticInitOK) const
{
  if (!_useDefaultGen) return 0 ;
 
  // Find the subset directVars that only depend on a single PDF in the product
  RooArgSet directSafe ;
  RooFIter dIter = directVars.fwdIterator() ;
  RooAbsArg* arg ;
  while((arg=(RooAbsArg*)dIter.next())) {
    if (isDirectGenSafe(*arg)) directSafe.add(*arg) ;
  }
 
 
  // Now find direct integrator for relevant components ;
  RooAbsPdf* pdf ;
  std::vector<Int_t> code;
  code.reserve(64);
  RooFIter pdfIter = _pdfList.fwdIterator();
  while((pdf=(RooAbsPdf*)pdfIter.next())) {
    RooArgSet pdfDirect ;
    Int_t pdfCode = pdf->getGenerator(directSafe,pdfDirect,staticInitOK);
    code.push_back(pdfCode);
    if (pdfCode != 0) {
      generateVars.add(pdfDirect) ;
    }
  }
 
 
  if (generateVars.getSize()>0) {
    Int_t masterCode = _genCode.store(code) ;
    return masterCode+1 ;
  } else {
    return 0 ;
  }
}
 
 
 
////////////////////////////////////////////////////////////////////////////////
/// Forward one-time initialization call to component generation initialization
/// methods.
 
void RooProdPdf::initGenerator(Int_t code)
{
  if (!_useDefaultGen) return ;
 
  const std::vector<Int_t>& codeList = _genCode.retrieve(code-1) ;
  RooAbsPdf* pdf ;
  Int_t i(0) ;
  RooFIter pdfIter = _pdfList.fwdIterator();
  while((pdf=(RooAbsPdf*)pdfIter.next())) {
    if (codeList[i]!=0) {
      pdf->initGenerator(codeList[i]) ;
    }
    i++ ;
  }
}
 
 
 
////////////////////////////////////////////////////////////////////////////////
/// Generate a single event with configuration specified by 'code'
/// Defer internal generation to components as encoded in the _genCode
/// registry for given generator code.
 
void RooProdPdf::generateEvent(Int_t code)
{
  if (!_useDefaultGen) return ;
 
  const std::vector<Int_t>& codeList = _genCode.retrieve(code-1) ;
  RooAbsPdf* pdf ;
  Int_t i(0) ;
  RooFIter pdfIter = _pdfList.fwdIterator();
  while((pdf=(RooAbsPdf*)pdfIter.next())) {
    if (codeList[i]!=0) {
      pdf->generateEvent(codeList[i]) ;
    }
    i++ ;
  }
}
 
 
 
////////////////////////////////////////////////////////////////////////////////
/// Return RooAbsArg components contained in the cache
 
RooArgList RooProdPdf::CacheElem::containedArgs(Action)
{
  RooArgList ret ;
  ret.add(_partList) ;
  ret.add(_numList) ;
  ret.add(_denList) ;
  if (_rearrangedNum) ret.add(*_rearrangedNum) ;
  if (_rearrangedDen) ret.add(*_rearrangedDen) ;
  return ret ;
 
}
 
 
 
////////////////////////////////////////////////////////////////////////////////
/// Hook function to print cache contents in tree printing of RooProdPdf
 
void RooProdPdf::CacheElem::printCompactTreeHook(ostream& os, const char* indent, Int_t curElem, Int_t maxElem)
{
   if (curElem==0) {
     os << indent << "RooProdPdf begin partial integral cache" << endl ;
   }
 
   RooFIter iter = _partList.fwdIterator() ;
   RooAbsArg* arg ;
   TString indent2(indent) ;
   indent2 += Form("[%d] ",curElem) ;
   while((arg=(RooAbsArg*)iter.next())) {
     arg->printCompactTree(os,indent2) ;
   }
 
   if (curElem==maxElem) {
     os << indent << "RooProdPdf end partial integral cache" << endl ;
   }
}
 
 
 
////////////////////////////////////////////////////////////////////////////////
/// Forward determination of safety of internal generator code to
/// component p.d.f that would generate the given observable
 
Bool_t RooProdPdf::isDirectGenSafe(const RooAbsArg& arg) const
{
  // Only override base class behaviour if default generator method is enabled
  if (!_useDefaultGen) return RooAbsPdf::isDirectGenSafe(arg) ;
 
  // Argument may appear in only one PDF component
  RooAbsPdf* pdf, *thePdf(0) ;
  RooFIter pdfIter = _pdfList.fwdIterator();
  while((pdf=(RooAbsPdf*)pdfIter.next())) {
 
    if (pdf->dependsOn(arg)) {
      // Found PDF depending on arg
 
      // If multiple PDFs depend on arg directGen is not safe
      if (thePdf) return kFALSE ;
 
      thePdf = pdf ;
    }
  }
  // Forward call to relevant component PDF
  return thePdf?(thePdf->isDirectGenSafe(arg)):kFALSE ;
}
 
 
 
////////////////////////////////////////////////////////////////////////////////
/// Look up user specified normalization set for given input PDF component
 
RooArgSet* RooProdPdf::findPdfNSet(RooAbsPdf& pdf) const
{
  Int_t idx = _pdfList.index(&pdf) ;
  if (idx<0) return 0 ;
  return (RooArgSet*) _pdfNSetList.At(idx) ;
}
 
 
 
////////////////////////////////////////////////////////////////////////////////
/// Return all parameter constraint p.d.f.s on parameters listed in constrainedParams.
/// The observables set is required to distinguish unambiguously p.d.f in terms
/// of observables and parameters, which are not constraints, and p.d.fs in terms
/// of parameters only, which can serve as constraints p.d.f.s
 
RooArgSet* RooProdPdf::getConstraints(const RooArgSet& observables, RooArgSet& constrainedParams, Bool_t stripDisconnected) const
{
  RooArgSet constraints ;
  RooArgSet pdfParams, conParams ;
 
  // Loop over p.d.f. components
  RooFIter piter = _pdfList.fwdIterator() ;
  RooAbsPdf* pdf ;
  while((pdf=(RooAbsPdf*)piter.next())) {
    // A constraint term is a p.d.f that does not depend on any of the listed observables
    // but does depends on any of the parameters that should be constrained
    if (!pdf->dependsOnValue(observables) && pdf->dependsOnValue(constrainedParams)) {
      constraints.add(*pdf) ;
      RooArgSet* tmp = pdf->getParameters(observables) ;
      conParams.add(*tmp,kTRUE) ;
      delete tmp ;
    } else {
      RooArgSet* tmp = pdf->getParameters(observables) ;
      pdfParams.add(*tmp,kTRUE) ;
      delete tmp ;
    }
  }
 
  // Strip any constraints that are completely decoupled from the other product terms
  RooArgSet* finalConstraints = new RooArgSet("constraints") ;
  RooFIter citer = constraints.fwdIterator() ;
  while((pdf=(RooAbsPdf*)citer.next())) {
    if (pdf->dependsOnValue(pdfParams) || !stripDisconnected) {
      finalConstraints->add(*pdf) ;
    } else {
      coutI(Minimization) << "RooProdPdf::getConstraints(" << GetName() << ") omitting term " << pdf->GetName()
           << " as constraint term as it does not share any parameters with the other pdfs in product. "
           << "To force inclusion in likelihood, add an explicit Constrain() argument for the target parameter" << endl ;
    }
  }
 
  // Now remove from constrainedParams all parameters that occur exclusively in constraint term and not in regular pdf term
 
  RooArgSet* cexl = (RooArgSet*) conParams.selectCommon(constrainedParams) ;
  cexl->remove(pdfParams,kTRUE,kTRUE) ;
  constrainedParams.remove(*cexl,kTRUE,kTRUE) ;
  delete cexl ;
 
  return finalConstraints ;
}
 
 
 
 
////////////////////////////////////////////////////////////////////////////////
/// Return all parameter constraint p.d.f.s on parameters listed in constrainedParams
/// The observables set is required to distinguish unambiguously p.d.f in terms
/// of observables and parameters, which are not constraints, and p.d.fs in terms
/// of parameters only, which can serve as constraints p.d.f.s
 
RooArgSet* RooProdPdf::getConnectedParameters(const RooArgSet& observables) const
{
  RooFIter iter = _pdfList.fwdIterator() ;
  RooAbsArg* arg ;
  RooArgSet* connectedPars  = new RooArgSet("connectedPars") ;
  while((arg=iter.next())) {
    // Check if term is relevant
    if (arg->dependsOn(observables)) {
      RooArgSet* tmp = arg->getParameters(observables) ;
      connectedPars->add(*tmp) ;
      delete tmp ;
    } else {
    }
  }
  return connectedPars ;
}
 
 
 
 
////////////////////////////////////////////////////////////////////////////////
 
void RooProdPdf::getParametersHook(const RooArgSet* nset, RooArgSet* params, Bool_t stripDisconnected) const
{
  if (!stripDisconnected) return ;
  if (!nset || nset->getSize()==0) return ;
 
  // Get/create appropriate term list for this normalization set
  Int_t code = getPartIntList(nset, nullptr);
  RooArgList & plist = static_cast<CacheElem*>(_cacheMgr.getObj(nset, &code))->_partList;
 
  // Strip any terms from params that do not depend on any term
  RooArgSet tostrip ;
  for (auto param : *params) {
    Bool_t anyDep(kFALSE) ;
    for (auto term : plist) {
      if (term->dependsOnValue(*param)) {
        anyDep=kTRUE ;
      }
    }
    if (!anyDep) {
      tostrip.add(*param) ;
    }
  }
 
  if (tostrip.getSize()>0) {
    params->remove(tostrip,kTRUE,kTRUE);
  }
 
}
 
 
 
////////////////////////////////////////////////////////////////////////////////
/// Interface function used by test statistics to freeze choice of range
/// for interpretation of conditional product terms
 
void RooProdPdf::selectNormalizationRange(const char* rangeName, Bool_t force)
{
  if (!force && _refRangeName) {
    return ;
  }
 
  fixRefRange(rangeName) ;
}
 
 
 
 
////////////////////////////////////////////////////////////////////////////////
 
void RooProdPdf::fixRefRange(const char* rangeName)
{
  _refRangeName = (TNamed*)RooNameReg::ptr(rangeName) ;
}
 
 
 
////////////////////////////////////////////////////////////////////////////////
/// Forward the plot sampling hint from the p.d.f. that defines the observable obs
 
std::list<Double_t>* RooProdPdf::plotSamplingHint(RooAbsRealLValue& obs, Double_t xlo, Double_t xhi) const
{
  RooAbsPdf* pdf ;
  RooFIter pdfIter = _pdfList.fwdIterator();
  while((pdf=(RooAbsPdf*)pdfIter.next())) {
    list<Double_t>* hint = pdf->plotSamplingHint(obs,xlo,xhi) ;
    if (hint) {
      return hint ;
    }
  }
 
  return 0 ;
}
 
 
 
////////////////////////////////////////////////////////////////////////////////
/// If all components that depend on obs are binned that so is the product
 
Bool_t RooProdPdf::isBinnedDistribution(const RooArgSet& obs) const
{
  RooAbsPdf* pdf ;
  RooFIter pdfIter = _pdfList.fwdIterator();
  while((pdf=(RooAbsPdf*)pdfIter.next())) {
    if (pdf->dependsOn(obs) && !pdf->isBinnedDistribution(obs)) {
      return kFALSE ;
    }
  }
 
  return kTRUE  ;
}
 
 
 
 
 
 
////////////////////////////////////////////////////////////////////////////////
/// Forward the plot sampling hint from the p.d.f. that defines the observable obs
 
std::list<Double_t>* RooProdPdf::binBoundaries(RooAbsRealLValue& obs, Double_t xlo, Double_t xhi) const
{
  RooAbsPdf* pdf ;
  RooFIter pdfIter = _pdfList.fwdIterator();
  while((pdf=(RooAbsPdf*)pdfIter.next())) {
    list<Double_t>* hint = pdf->binBoundaries(obs,xlo,xhi) ;
    if (hint) {
      return hint ;
    }
  }
 
  return 0 ;
}
 
 
////////////////////////////////////////////////////////////////////////////////
/// Label OK'ed components of a RooProdPdf with cache-and-track, _and_ label all RooProdPdf
/// descendants with extra informationa about (conditional) normalization, needed to be able
/// to Cache-And-Track them outside the RooprodPdf context
 
void RooProdPdf::setCacheAndTrackHints(RooArgSet& trackNodes)
{
  RooFIter piter = pdfList().fwdIterator() ;
  RooAbsArg* parg ;
  while ((parg=piter.next())) {
 
    if (parg->canNodeBeCached()==Always) {
      trackNodes.add(*parg) ;
      //cout << "tracking node RooProdPdf component " << parg->IsA()->GetName() << "::" << parg->GetName() << endl ;
 
      // Additional processing to fix normalization sets in case product defines conditional observables
      RooArgSet* pdf_nset = findPdfNSet((RooAbsPdf&)(*parg)) ;
      if (pdf_nset) {
   // Check if conditional normalization is specified
   if (string("nset")==pdf_nset->GetName() && pdf_nset->getSize()>0) {
     RooNameSet n(*pdf_nset) ;
     parg->setStringAttribute("CATNormSet",n.content()) ;
   }
   if (string("cset")==pdf_nset->GetName()) {
     RooNameSet c(*pdf_nset) ;
     parg->setStringAttribute("CATCondSet",c.content()) ;
   }
      } else {
   coutW(Optimization) << "RooProdPdf::setCacheAndTrackHints(" << GetName() << ") WARNING product pdf does not specify a normalization set for component " << parg->GetName() << endl ;
      }
    }
  }
}
 
 
 
////////////////////////////////////////////////////////////////////////////////
/// Customized printing of arguments of a RooProdPdf to more intuitively reflect the contents of the
/// product operator construction
 
void RooProdPdf::printMetaArgs(ostream& os) const
{
  RooFIter niter = _pdfNSetList.fwdIterator() ;
  for (int i=0 ; i<_pdfList.getSize() ; i++) {
    if (i>0) os << " * " ;
    RooArgSet* ncset = (RooArgSet*) niter.next() ;
    os << _pdfList.at(i)->GetName() ;
    if (ncset->getSize()>0) {
      if (string("nset")==ncset->GetName()) {
   os << *ncset  ;
      } else {
   os << "|" ;
   RooFIter nciter = ncset->fwdIterator() ;
   RooAbsArg* arg ;
   Bool_t first(kTRUE) ;
   while((arg=(RooAbsArg*)nciter.next())) {
     if (!first) {
       os << "," ;
     } else {
       first = kFALSE ;
     }
     os << arg->GetName() ;
   }
      }
    }
  }
  os << " " ;
}
 
 
 
////////////////////////////////////////////////////////////////////////////////
/// Implement support for node removal
 
Bool_t RooProdPdf::redirectServersHook(const RooAbsCollection& /*newServerList*/, Bool_t /*mustReplaceAll*/, Bool_t nameChange, Bool_t /*isRecursive*/)
{
  if (nameChange && _pdfList.find("REMOVAL_DUMMY")) {
 
    cxcoutD(LinkStateMgmt) << "RooProdPdf::redirectServersHook(" << GetName() << "): removing REMOVAL_DUMMY" << endl ;
 
    // Remove node from _pdfList proxy and remove corresponding entry from normset list
    RooAbsArg* pdfDel = _pdfList.find("REMOVAL_DUMMY") ;
 
    TObject* setDel = _pdfNSetList.At(_pdfList.index("REMOVAL_DUMMY")) ;
    _pdfList.remove(*pdfDel) ;
    _pdfNSetList.Remove(setDel) ;
 
    // Clear caches
    _cacheMgr.reset() ;
  }
  return kFALSE ;
}