RooPlot.cxx

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/*****************************************************************************
 * 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 RooPlot.cxx
\class RooPlot
\ingroup Roofitcore
 
A RooPlot is a plot frame and a container for graphics objects
within that frame. As a frame, it provides the TH1-style public interface
for settting plot ranges, configuring axes, etc. As a container, it
holds an arbitrary set of objects that might be histograms of data,
curves representing a fit model, or text labels. Use the Draw()
method to draw a frame and the objects it contains. Use the various
add...() methods to add objects to be drawn.  In general, the
add...() methods create a private copy of the object you pass them
and return a pointer to this copy. The caller owns the input object
and this class owns the returned object.
All RooAbsReal and RooAbsData derived classes implement plotOn()
functions that facilitate to plot themselves on a given RooPlot, e.g.
~~~ {.cpp}
RooPlot *frame = x.frame() ;
data.plotOn(frame) ;
pdf.plotOn(frame) ;
~~~
These high level functions also take care of any projections
or other mappings that need to be made to plot a multi-dimensional
object onto a one-dimensional plot.
**/
 
#include "RooPlot.h"
 
#include "RooAbsReal.h"
#include "RooAbsRealLValue.h"
#include "RooPlotable.h"
#include "RooArgSet.h"
#include "RooCurve.h"
#include "RooHist.h"
#include "RooMsgService.h"
 
#include "TClass.h"
#include "TH1D.h"
#include "TBrowser.h"
#include "TPad.h"
 
#include "TAttLine.h"
#include "TAttFill.h"
#include "TAttMarker.h"
#include "TAttText.h"
#include "TDirectory.h"
#include "TDirectoryFile.h"
#include "TLegend.h"
 
#include "Riostream.h"
#include <string.h>
 
using namespace std;
 
ClassImp(RooPlot);
;
 
Bool_t RooPlot::_addDirStatus = kTRUE ;
 
Bool_t RooPlot::addDirectoryStatus() { return _addDirStatus ; }
Bool_t RooPlot::setAddDirectoryStatus(Bool_t flag) { Bool_t ret = flag ; _addDirStatus = flag ; return ret ; }
 
 
////////////////////////////////////////////////////////////////////////////////
/// Default constructor
/// coverity[UNINIT_CTOR]
 
RooPlot::RooPlot() : _hist(0), _plotVarClone(0), _plotVarSet(0), _normVars(0), _normObj(0), _dir(0)
{
  _iterator= _items.MakeIterator() ;
 
  if (gDirectory && addDirectoryStatus()) {
    _dir = gDirectory ;
    gDirectory->Append(this) ;
  }
}
 
 
////////////////////////////////////////////////////////////////////////////////
/// Constructor of RooPlot with range [xmin,xmax]
 
RooPlot::RooPlot(Double_t xmin, Double_t xmax) :
  _hist(0), _items(), _plotVarClone(0), _plotVarSet(0), _normObj(0),
  _defYmin(1e-5), _defYmax(1), _dir(0)
{
  Bool_t histAddDirStatus = TH1::AddDirectoryStatus();
  TH1::AddDirectory(kFALSE) ;
 
  _hist = new TH1D(histName(),"A RooPlot",100,xmin,xmax) ;
  _hist->Sumw2(kFALSE) ;
  _hist->GetSumw2()->Set(0) ;
 
 
  TH1::AddDirectory(histAddDirStatus) ;
 
 
  // Create an empty frame with the specified x-axis limits.
  initialize();
 
}
 
 
 
////////////////////////////////////////////////////////////////////////////////
/// Construct of a two-dimensioanl RooPlot with ranges [xmin,xmax] x [ymin,ymax]
 
RooPlot::RooPlot(Double_t xmin, Double_t xmax, Double_t ymin, Double_t ymax) :
  _hist(0), _items(), _plotVarClone(0),
  _plotVarSet(0), _normObj(0), _defYmin(1e-5), _defYmax(0), _dir(0)
{
  Bool_t histAddDirStatus = TH1::AddDirectoryStatus();
  TH1::AddDirectory(kFALSE) ;
 
  _hist = new TH1D(histName(),"A RooPlot",100,xmin,xmax) ;
  _hist->Sumw2(kFALSE) ;
  _hist->GetSumw2()->Set(0) ;
 
  TH1::AddDirectory(histAddDirStatus) ;
 
  SetMinimum(ymin);
  SetMaximum(ymax);
  initialize();
}
 
 
////////////////////////////////////////////////////////////////////////////////
/// Construct a two-dimensional RooPlot with ranges and properties taken
/// from variables var1 and var2
 
RooPlot::RooPlot(const RooAbsRealLValue &var1, const RooAbsRealLValue &var2) :
  _hist(0), _items(),
  _plotVarClone(0), _plotVarSet(0), _normObj(0), _defYmin(1e-5), _defYmax(0), _dir(0)
{
  Bool_t histAddDirStatus = TH1::AddDirectoryStatus();
  TH1::AddDirectory(kFALSE) ;
 
  _hist = new TH1D(histName(),"A RooPlot",100,var1.getMin(),var1.getMax()) ;
  _hist->Sumw2(kFALSE) ;
  _hist->GetSumw2()->Set(0) ;
 
  TH1::AddDirectory(histAddDirStatus) ;
 
  if(!var1.hasMin() || !var1.hasMax()) {
    coutE(InputArguments) << "RooPlot::RooPlot: cannot create plot for variable without finite limits: "
    << var1.GetName() << endl;
    return;
  }
  if(!var2.hasMin() || !var2.hasMax()) {
    coutE(InputArguments) << "RooPlot::RooPlot: cannot create plot for variable without finite limits: "
    << var1.GetName() << endl;
    return;
  }
  SetMinimum(var2.getMin());
  SetMaximum(var2.getMax());
  SetXTitle(var1.getTitle(kTRUE));
  SetYTitle(var2.getTitle(kTRUE));
  initialize();
}
 
 
////////////////////////////////////////////////////////////////////////////////
/// Construct a two-dimensional RooPlot with ranges and properties taken
/// from variables var1 and var2 but with an overriding range definition
/// of [xmin,xmax] x [ymin,ymax]
 
RooPlot::RooPlot(const RooAbsRealLValue &var1, const RooAbsRealLValue &var2,
       Double_t xmin, Double_t xmax, Double_t ymin, Double_t ymax) :
  _hist(0), _items(), _plotVarClone(0),
  _plotVarSet(0), _normObj(0), _defYmin(1e-5), _defYmax(0), _dir(0)
{
  Bool_t histAddDirStatus = TH1::AddDirectoryStatus();
  TH1::AddDirectory(kFALSE) ;
 
  _hist = new TH1D(histName(),"A RooPlot",100,xmin,xmax) ;
  _hist->Sumw2(kFALSE) ;
  _hist->GetSumw2()->Set(0) ;
 
  TH1::AddDirectory(histAddDirStatus) ;
 
  SetMinimum(ymin);
  SetMaximum(ymax);
  SetXTitle(var1.getTitle(kTRUE));
  SetYTitle(var2.getTitle(kTRUE));
  initialize();
}
 
 
////////////////////////////////////////////////////////////////////////////////
/// Create an 1-dimensional with all properties taken from 'var', but
/// with an explicit range [xmin,xmax] and a default binning of 'nbins'
 
RooPlot::RooPlot(const char* name, const char* title, const RooAbsRealLValue &var, Double_t xmin, Double_t xmax, Int_t nbins) :
  _hist(0), _items(),
  _plotVarClone(0), _plotVarSet(0), _normObj(0), _defYmin(1e-5), _defYmax(1), _dir(0)
{
  Bool_t histAddDirStatus = TH1::AddDirectoryStatus();
  TH1::AddDirectory(kFALSE) ;
 
  _hist = new TH1D(name,title,nbins,xmin,xmax) ;
  _hist->Sumw2(kFALSE) ;
  _hist->GetSumw2()->Set(0) ;
 
  TH1::AddDirectory(histAddDirStatus) ;
 
  // plotVar can be a composite in case of a RooDataSet::plot, need deepClone
  _plotVarSet = (RooArgSet*) RooArgSet(var).snapshot() ;
  _plotVarClone= (RooAbsRealLValue*)_plotVarSet->find(var.GetName()) ;
 
  TString xtitle= var.getTitle(kTRUE);
  SetXTitle(xtitle.Data());
 
  initialize();
 
  _normBinWidth = (xmax-xmin)/nbins ;
}
 
 
////////////////////////////////////////////////////////////////////////////////
/// Create an 1-dimensional with all properties taken from 'var', but
/// with an explicit range [xmin,xmax] and a default binning of 'nbins'
 
RooPlot::RooPlot(const RooAbsRealLValue &var, Double_t xmin, Double_t xmax, Int_t nbins) :
  _hist(0), _items(),
  _plotVarClone(0), _plotVarSet(0), _normObj(0), _defYmin(1e-5), _defYmax(1), _dir(0)
{
  Bool_t histAddDirStatus = TH1::AddDirectoryStatus();
  TH1::AddDirectory(kFALSE) ;
 
  _hist = new TH1D(histName(),"RooPlot",nbins,xmin,xmax) ;
  _hist->Sumw2(kFALSE) ;
  _hist->GetSumw2()->Set(0) ;
 
  TH1::AddDirectory(histAddDirStatus) ;
 
  // plotVar can be a composite in case of a RooDataSet::plot, need deepClone
  _plotVarSet = (RooArgSet*) RooArgSet(var).snapshot() ;
  _plotVarClone= (RooAbsRealLValue*)_plotVarSet->find(var.GetName()) ;
 
  TString xtitle= var.getTitle(kTRUE);
  SetXTitle(xtitle.Data());
 
  TString title("A RooPlot of \"");
  title.Append(var.getTitle());
  title.Append("\"");
  SetTitle(title.Data());
  initialize();
 
  _normBinWidth = (xmax-xmin)/nbins ;
}
 
////////////////////////////////////////////////////////////////////////////////
/// Create a new frame for a given variable in x. This is just a
/// wrapper for the RooPlot constructor with the same interface.
/// 
/// More details.
/// \param[in] var The variable on the x-axis
/// \param[in] xmin Left edge of the x-axis
/// \param[in] xmax Right edge of the x-axis
/// \param[in] nBins number of bins on the x-axis
RooPlot* RooPlot::frame(const RooAbsRealLValue &var, Double_t xmin, Double_t xmax, Int_t nBins){
  return new RooPlot(var,xmin,xmax,nBins);
}
 
////////////////////////////////////////////////////////////////////////////////
/// Create a new frame for a given variable in x, adding bin labels.
/// The binning will be extracted from the variable given. The bin
/// labels will be set as "%g-%g" for the left and right edges of each
/// bin of the given variable.
///
/// More details.
/// \param[in] var The variable on the x-axis
RooPlot* RooPlot::frameWithLabels(const RooAbsRealLValue &var){
  RooPlot* pl = new RooPlot();
  int nbins = var.getBinning().numBins();
 
  Bool_t histAddDirStatus = TH1::AddDirectoryStatus();
  TH1::AddDirectory(kFALSE) ;
  pl->_hist = new TH1D(pl->histName(),"RooPlot",nbins,var.getMin(),var.getMax()) ;
  pl->_hist->Sumw2(kFALSE) ;
  pl->_hist->GetSumw2()->Set(0) ;
  TH1::AddDirectory(histAddDirStatus) ;
 
  pl->_hist->SetNdivisions(-nbins);
  for(int i=0; i<nbins; ++i){
    TString s = TString::Format("%g-%g",var.getBinning().binLow(i),var.getBinning().binHigh(i));
    pl->_hist->GetXaxis()->SetBinLabel(i+1,s);
  }
 
  // plotVar can be a composite in case of a RooDataSet::plot, need deepClone
  pl->_plotVarSet = (RooArgSet*) RooArgSet(var).snapshot() ;
  pl->_plotVarClone= (RooAbsRealLValue*)pl->_plotVarSet->find(var.GetName()) ;
 
  TString xtitle= var.getTitle(kTRUE);
  pl->SetXTitle(xtitle.Data());
 
  TString title("A RooPlot of \"");
  title.Append(var.getTitle());
  title.Append("\"");
  pl->SetTitle(title.Data());
  pl->initialize();
 
  pl->_normBinWidth = 1.;
  return pl;
}
 
////////////////////////////////////////////////////////////////////////////////
/// Return empty clone of current RooPlot
 
RooPlot* RooPlot::emptyClone(const char* name)
{
  RooPlot* clone = new RooPlot(*_plotVarClone,_hist->GetXaxis()->GetXmin(),_hist->GetXaxis()->GetXmax(),_hist->GetNbinsX()) ;
  clone->SetName(name) ;
  return clone ;
}
 
 
////////////////////////////////////////////////////////////////////////////////
/// Perform initialization that is common to all constructors.
 
void RooPlot::initialize()
{
  SetName(histName()) ;
 
  if (gDirectory && addDirectoryStatus()) {
    _dir = gDirectory ;
    gDirectory->Append(this) ;
  }
 
  // We do not have useful stats of our own
  _hist->SetStats(kFALSE);
  // Default vertical padding of our enclosed objects
  setPadFactor(0.05);
  // We don't know our normalization yet
  _normNumEvts= 0;
  _normBinWidth = 0;
  _normVars= 0;
  // Create an iterator over our enclosed objects
  _iterator= _items.MakeIterator();
  assert(0 != _iterator);
}
 
 
////////////////////////////////////////////////////////////////////////////////
/// Construct automatic name of internal TH1
 
TString RooPlot::histName() const
{
  if (_plotVarClone) {
    return TString(Form("frame_%s_%lx",_plotVarClone->GetName(),(ULong_t)this)) ;
  } else {
    return TString(Form("frame_%lx",(ULong_t)this)) ;
  }
}
 
 
////////////////////////////////////////////////////////////////////////////////
/// Destructor
 
RooPlot::~RooPlot()
{
  // Delete the items in our container and our iterator.
  if (_dir) {
    if (!_dir->TestBit(TDirectoryFile::kCloseDirectory)) {
      _dir->GetList()->RecursiveRemove(this) ;
    }
  }
 
  _items.Delete();
  delete _iterator;
  if(_plotVarSet) delete _plotVarSet;
  if(_normVars) delete _normVars;
  delete _hist ;
 
}
 
 
////////////////////////////////////////////////////////////////////////////////
/// Install the given set of observables are reference normalization
/// variables for this frame. These observables are e.g. later used
/// to automatically project out observables when plotting functions
/// on this frame. This function is only effective when called the
/// first time on a frame
 
void RooPlot::updateNormVars(const RooArgSet &vars)
{
  if(0 == _normVars) _normVars= (RooArgSet*) vars.snapshot(kTRUE);
}
 
 
////////////////////////////////////////////////////////////////////////////////
/// A plot object is a frame without any bin contents of its own so this
/// method always returns zero.
 
Stat_t RooPlot::GetBinContent(Int_t /*i*/) const {
  return 0;
}
 
 
////////////////////////////////////////////////////////////////////////////////
/// A plot object is a frame without any bin contents of its own so this
/// method always returns zero.
 
Stat_t RooPlot::GetBinContent(Int_t, Int_t) const
{
  return 0;
}
 
 
////////////////////////////////////////////////////////////////////////////////
/// A plot object is a frame without any bin contents of its own so this
/// method always returns zero.
 
Stat_t RooPlot::GetBinContent(Int_t, Int_t, Int_t) const
{
  return 0;
}
 
 
 
////////////////////////////////////////////////////////////////////////////////
/// Add a generic object to this plot. The specified options will be
/// used to Draw() this object later. The caller transfers ownership
/// of the object with this call, and the object will be deleted
/// when its containing plot object is destroyed.
 
void RooPlot::addObject(TObject *obj, Option_t *drawOptions, Bool_t invisible)
{
  if(0 == obj) {
    coutE(InputArguments) << fName << "::addObject: called with a null pointer" << endl;
    return;
  }
  DrawOpt opt(drawOptions) ;
  opt.invisible = invisible ;
  _items.Add(obj,opt.rawOpt());
}
 
 
////////////////////////////////////////////////////////////////////////////////
/// Add a TH1 histogram object to this plot. The specified options
/// will be used to Draw() this object later. "SAME" will be added to
/// the options if they are not already present. The caller transfers
/// ownership of the object with this call, and the object will be
/// deleted when its containing plot object is destroyed.
 
void RooPlot::addTH1(TH1 *hist, Option_t *drawOptions, Bool_t invisible)
{
  if(0 == hist) {
    coutE(InputArguments) << fName << "::addTH1: called with a null pointer" << endl;
    return;
  }
  // check that this histogram is really 1D
  if(1 != hist->GetDimension()) {
    coutE(InputArguments) << fName << "::addTH1: cannot plot histogram with "
    << hist->GetDimension() << " dimensions" << endl;
    return;
  }
 
  // add option "SAME" if necessary
  TString options(drawOptions);
  options.ToUpper();
  if(!options.Contains("SAME")) options.Append("SAME");
 
  // update our y-axis label and limits
  updateYAxis(hist->GetMinimum(),hist->GetMaximum(),hist->GetYaxis()->GetTitle());
 
  // use this histogram's normalization if necessary
  updateFitRangeNorm(hist);
 
  // add the histogram to our list
  addObject(hist,options.Data(),invisible);
}
 
 
namespace {
  // this helper function is intended to translate a graph from a regular axis to a labelled axis
  // this version uses TGraph, which is a parent of RooCurve
  void translateGraph(TH1* hist, RooAbsRealLValue* xvar, TGraph* graph){
    // if the graph already has a labelled axis, don't do anything
    if(graph->GetXaxis()->IsAlphanumeric()) return;
    double xmin = hist->GetXaxis()->GetXmin();
    double xmax = hist->GetXaxis()->GetXmax();
    if(graph->TestBit(TGraph::kIsSortedX)){
      // sorted graphs are "line graphs"
      // evaluate the graph at the lower and upper edge as well as the center of each bin
      std::vector<double> x;
      std::vector<double> y;
      x.push_back(xmin);
      y.push_back(graph->Eval(xvar->getBinning().binLow(0)));
      for(int i=0; i<hist->GetNbinsX(); ++i){
        x.push_back(hist->GetXaxis()->GetBinUpEdge(i+1));
        y.push_back(graph->Eval(xvar->getBinning().binHigh(i)));
        x.push_back(hist->GetXaxis()->GetBinCenter(i+1));
        y.push_back(graph->Eval(xvar->getBinning().binCenter(i)));                
      }
      int n = x.size();
      graph->Set(n);
      for(int i=0; i<n; ++i){
        graph->SetPoint(i,x[i],y[i]);
      }
      graph->Sort();
    } else {
      // unsorted graphs are "area graphs"
      std::map<int,double> minValues;
      std::map<int,double> maxValues;
      int n = graph->GetN();
      double x, y;
      // for each bin, find the min and max points to form an envelope
      for(int i=0; i<n; ++i){
        graph->GetPoint(i,x,y);
        int bin = xvar->getBinning().binNumber(x)+1;
        if(maxValues.find(bin)!=maxValues.end()){
          maxValues[bin] = std::max(maxValues[bin],y);
        } else {
          maxValues[bin] = y;
        }
        if(minValues.find(bin)!=minValues.end()){
          minValues[bin] = std::min(minValues[bin],y);
        } else {
          minValues[bin] = y;
        }
      }
      double xminY = graph->Eval(xmin);
      double xmaxY = graph->Eval(xmax);
      graph->Set(hist->GetNbinsX()+2);
      int np=0;
      graph->SetPoint(np,xmin,xminY);
      // assign the calculated envelope boundaries to the bin centers of the bins
      for(auto it = maxValues.begin(); it != maxValues.end(); ++it){
        graph->SetPoint(++np,hist->GetXaxis()->GetBinCenter(it->first),it->second);
      }
      graph->SetPoint(++np,xmax,xmaxY);
      for(auto it = minValues.rbegin(); it != minValues.rend(); ++it){
        graph->SetPoint(++np,hist->GetXaxis()->GetBinCenter(it->first),it->second);
      }
      graph->SetPoint(++np,xmin,xminY);
    }
    // make sure that the graph also has the labels set, such that subsequent calls to translate this graph will not do anything
    graph->GetXaxis()->Set(hist->GetNbinsX(),xmin,xmax);
    for(int i=0; i<hist->GetNbinsX(); ++i){
      graph->GetXaxis()->SetBinLabel(i+1,hist->GetXaxis()->GetBinLabel(i+1));
    }
  }
  // this version uses TGraphErrors, which is a parent of RooHist
  void translateGraph(TH1* hist, RooAbsRealLValue* xvar, TGraphAsymmErrors* graph){
    // if the graph already has a labelled axis, don't do anything
    if(graph->GetXaxis()->IsAlphanumeric()) return; 
    int n = graph->GetN();
    double xmin = hist->GetXaxis()->GetXmin();
    double xmax = hist->GetXaxis()->GetXmax();
    double x, y;
    // as this graph is histogram-like, we expect there to be one point per bin
    // we just move these points to the respective bin centers
    for(int i=0; i<n; ++i){
      if(graph->GetPoint(i,x,y)!=i) break;
      int bin = xvar->getBinning().binNumber(x);
      graph->SetPoint(i,hist->GetXaxis()->GetBinCenter(bin+1),y);
      graph->SetPointEXhigh(i,0.5*hist->GetXaxis()->GetBinWidth(bin+1));
      graph->SetPointEXlow(i,0.5*hist->GetXaxis()->GetBinWidth(bin+1));
    }
    graph->GetXaxis()->Set(hist->GetNbinsX(),xmin,xmax);
    // make sure that the graph also has the labels set, such that subsequent calls to translate this graph will not do anything    
    for(int i=0; i<hist->GetNbinsX(); ++i){
      graph->GetXaxis()->SetBinLabel(i+1,hist->GetXaxis()->GetBinLabel(i+1));
    }
  }
}
 
////////////////////////////////////////////////////////////////////////////////
/// Add the specified plotable object to our plot. Increase our y-axis
/// limits to fit this object if necessary. The default lower-limit
/// is zero unless we are plotting an object that takes on negative values.
/// This call transfers ownership of the plotable object to this class.
/// The plotable object will be deleted when this plot object is deleted.
void RooPlot::addPlotable(RooPlotable *plotable, Option_t *drawOptions, Bool_t invisible, Bool_t refreshNorm)
{
  // update our y-axis label and limits
  updateYAxis(plotable->getYAxisMin(),plotable->getYAxisMax(),plotable->getYAxisLabel());
 
  // use this object's normalization if necessary
  updateFitRangeNorm(plotable,refreshNorm) ;
 
  // add this element to our list and remember its drawing option
  TObject *obj= plotable->crossCast();
  if(0 == obj) {
    coutE(InputArguments) << fName << "::add: cross-cast to TObject failed (nothing added)" << endl;
  }
  else {
    // if the frame axis is alphanumeric, the coordinates of the graph need to be translated to this binning
    if(this->_hist->GetXaxis()->IsAlphanumeric()){
      if(obj->InheritsFrom(RooCurve::Class())){
        ::translateGraph(this->_hist,_plotVarClone,static_cast<RooCurve*>(obj));
      } else if(obj->InheritsFrom(RooHist::Class())){
        ::translateGraph(this->_hist,_plotVarClone,static_cast<RooHist*>(obj));
      }
    }
    
    DrawOpt opt(drawOptions) ;
    opt.invisible = invisible ;
    _items.Add(obj,opt.rawOpt());
  }
}
 
 
////////////////////////////////////////////////////////////////////////////////
/// Update our plot normalization over our plot variable's fit range,
/// which will be determined by the first suitable object added to our plot.
 
void RooPlot::updateFitRangeNorm(const TH1* hist)
{
  const TAxis* xa = ((TH1*)hist)->GetXaxis() ;
  _normBinWidth = (xa->GetXmax()-xa->GetXmin())/hist->GetNbinsX() ;
  _normNumEvts = hist->GetEntries()/_normBinWidth ;
}
 
 
////////////////////////////////////////////////////////////////////////////////
/// Update our plot normalization over our plot variable's fit range,
/// which will be determined by the first suitable object added to our plot.
 
void RooPlot::updateFitRangeNorm(const RooPlotable* rp, Bool_t refreshNorm)
{
  if (_normNumEvts != 0) {
 
    // If refresh feature is disabled stop here
    if (!refreshNorm) return ;
 
    Double_t corFac(1.0) ;
    if (dynamic_cast<const RooHist*>(rp)) corFac = _normBinWidth/rp->getFitRangeBinW() ;
 
 
    if (fabs(rp->getFitRangeNEvt()/corFac-_normNumEvts)>1e-6) {
      coutI(Plotting) << "RooPlot::updateFitRangeNorm: New event count of " << rp->getFitRangeNEvt()/corFac
            << " will supercede previous event count of " << _normNumEvts << " for normalization of PDF projections" << endl ;
    }
 
    // Nominal bin width (i.e event density) is already locked in by previously drawn histogram
    // scale this histogram to match that density
    _normNumEvts = rp->getFitRangeNEvt()/corFac ;
    _normObj = rp ;
    // cout << "correction factor = " << _normBinWidth << "/" << rp->getFitRangeBinW() << endl ;
    // cout << "updating numevts to " << _normNumEvts << endl ;
 
  } else {
 
    _normObj = rp ;
    _normNumEvts = rp->getFitRangeNEvt() ;
    if (rp->getFitRangeBinW()) {
      _normBinWidth = rp->getFitRangeBinW() ;
    }
 
    // cout << "updating numevts to " << _normNumEvts << endl ;
  }
 
}
 
 
 
////////////////////////////////////////////////////////////////////////////////
/// Update our y-axis limits to accomodate an object whose spread
/// in y is (ymin,ymax). Use the specified y-axis label if we don't
/// have one assigned already.
 
void RooPlot::updateYAxis(Double_t ymin, Double_t ymax, const char *label)
{
  // force an implicit lower limit of zero if appropriate
  if(GetMinimum() == 0 && ymin > 0) ymin= 0;
 
  // calculate padded values
  Double_t ypad= getPadFactor()*(ymax-ymin);
  ymax+= ypad;
  if(ymin < 0) ymin-= ypad;
 
  // update our limits if necessary
  if(GetMaximum() < ymax) {
    _defYmax = ymax ;
    SetMaximum(ymax);
    // if we don't do this - Unzoom on y-axis will reset upper bound to 1
    _hist->SetBinContent(1,ymax) ;
  }
  if(GetMinimum() > ymin) {
    _defYmin = ymin ;
    SetMinimum(ymin);
  }
 
  // use the specified y-axis label if we don't have one already
  if(0 == strlen(_hist->GetYaxis()->GetTitle())) _hist->SetYTitle(label);
}
 
 
////////////////////////////////////////////////////////////////////////////////
/// Draw this plot and all of the elements it contains. The specified options
/// only apply to the drawing of our frame. The options specified in our add...()
/// methods will be used to draw each object we contain.
 
void RooPlot::Draw(Option_t *option)
{
  TString optArg = option ;
  optArg.ToLower() ;
 
  // This draw options prevents the histogram with one dummy entry
  // to be drawn
  if (optArg.Contains("same")) {
    _hist->Draw("FUNCSAME");
  } else {
    _hist->Draw("FUNC");
  }
 
  _iterator->Reset();
  TObject *obj = 0;
  while((obj= _iterator->Next())) {
    DrawOpt opt(_iterator->GetOption()) ;
    if (!opt.invisible) {
       //LM:  in case of a TGraph derived object, do not use default "" option
       // which is "ALP" from 5.34.10 (and will then redrawn the axis) but  use "LP"
       if (!strlen(opt.drawOptions) && obj->IsA()->InheritsFrom(TGraph::Class()) ) strlcpy(opt.drawOptions,"LP",3);
       obj->Draw(opt.drawOptions);
    }
  }
 
  _hist->Draw("AXISSAME");
}
 
 
 
////////////////////////////////////////////////////////////////////////////////
/// Print frame name
 
void RooPlot::printName(ostream& os) const
{
  os << GetName() ;
}
 
 
////////////////////////////////////////////////////////////////////////////////
/// Print frame title
 
void RooPlot::printTitle(ostream& os) const
{
  os << GetTitle() ;
}
 
 
////////////////////////////////////////////////////////////////////////////////
/// Print frame class name
 
void RooPlot::printClassName(ostream& os) const
{
  os << IsA()->GetName() ;
}
 
 
 
////////////////////////////////////////////////////////////////////////////////
 
void RooPlot::printArgs(ostream& os) const
{
  if (_plotVarClone) {
    os << "[" ;
    _plotVarClone->printStream(os,kName,kInline) ;
    os << "]" ;
  }
}
 
 
 
////////////////////////////////////////////////////////////////////////////////
/// Print frame arguments
 
void RooPlot::printValue(ostream& os) const
{
  os << "(" ;
  _iterator->Reset();
  TObject *obj = 0;
  Bool_t first(kTRUE) ;
  while((obj= _iterator->Next())) {
    if (first) {
      first=kFALSE ;
    } else {
      os << "," ;
    }
    if(obj->IsA()->InheritsFrom(RooPrintable::Class())) {
      RooPrintable* po = dynamic_cast<RooPrintable*>(obj) ;
      // coverity[FORWARD_NULL]
      po->printStream(os,kClassName|kName,kInline) ;
    }
    // is it a TNamed subclass?
    else {
      os << obj->ClassName() << "::" << obj->GetName() ;
    }
  }
  os << ")" ;
}
 
 
////////////////////////////////////////////////////////////////////////////////
/// Frame detailed printing
 
void RooPlot::printMultiline(ostream& os, Int_t /*content*/, Bool_t verbose, TString indent) const
{
  TString deeper(indent);
  deeper.Append("    ");
  if(0 != _plotVarClone) {
    os << indent << "RooPlot " << GetName() << " (" << GetTitle() << ") plots variable ";
    _plotVarClone->printStream(os,kName|kTitle,kSingleLine,"");
  }
  else {
    os << indent << "RooPlot " << GetName() << " (" << GetTitle() << ") has no associated plot variable" << endl ;
  }
  os << indent << "  Plot frame contains " << _items.GetSize() << " object(s):" << endl;
 
  if(verbose) {
    _iterator->Reset();
    TObject *obj = 0;
    Int_t i=0 ;
    while((obj= _iterator->Next())) {
      os << deeper << "[" << i++ << "] (Options=\"" << _iterator->GetOption() << "\") ";
      // Is this a printable object?
      if(obj->IsA()->InheritsFrom(RooPrintable::Class())) {
   RooPrintable* po = dynamic_cast<RooPrintable*>(obj) ;
   if (po) {
     po->printStream(os,kName|kClassName|kArgs|kExtras,kSingleLine) ;
   }
      }
      // is it a TNamed subclass?
      else {
   os << obj->ClassName() << "::" << obj->GetName() << endl;
      }
    }
  }
}
 
 
 
////////////////////////////////////////////////////////////////////////////////
/// Return the name of the object at slot 'idx' in this RooPlot.
/// If the given index is out of range, return a null pointer
 
const char* RooPlot::nameOf(Int_t idx) const
{
  TObject* obj = _items.At(idx) ;
  if (!obj) {
    coutE(InputArguments) << "RooPlot::nameOf(" << GetName() << ") index " << idx << " out of range" << endl ;
    return 0 ;
  }
  return obj->GetName() ;
}
 
 
 
////////////////////////////////////////////////////////////////////////////////
/// Return the name of the object at slot 'idx' in this RooPlot.
/// If the given index is out of range, return a null pointer
 
TObject* RooPlot::getObject(Int_t idx) const
{
  TObject* obj = _items.At(idx) ;
  if (!obj) {
    coutE(InputArguments) << "RooPlot::getObject(" << GetName() << ") index " << idx << " out of range" << endl ;
    return 0 ;
  }
  return obj ;
}
 
 
 
////////////////////////////////////////////////////////////////////////////////
/// Return a pointer to the line attributes of the named object in this plot,
/// or zero if the named object does not exist or does not have line attributes.
 
TAttLine *RooPlot::getAttLine(const char *name) const
{
  return dynamic_cast<TAttLine*>(findObject(name));
}
 
 
////////////////////////////////////////////////////////////////////////////////
/// Return a pointer to the fill attributes of the named object in this plot,
/// or zero if the named object does not exist or does not have fill attributes.
 
TAttFill *RooPlot::getAttFill(const char *name) const
{
  return dynamic_cast<TAttFill*>(findObject(name));
}
 
 
////////////////////////////////////////////////////////////////////////////////
/// Return a pointer to the marker attributes of the named object in this plot,
/// or zero if the named object does not exist or does not have marker attributes.
 
TAttMarker *RooPlot::getAttMarker(const char *name) const
{
  return dynamic_cast<TAttMarker*>(findObject(name));
}
 
 
////////////////////////////////////////////////////////////////////////////////
/// Return a pointer to the text attributes of the named object in this plot,
/// or zero if the named object does not exist or does not have text attributes.
 
TAttText *RooPlot::getAttText(const char *name) const
{
  return dynamic_cast<TAttText*>(findObject(name));
}
 
 
 
////////////////////////////////////////////////////////////////////////////////
/// Return a RooCurve pointer of the named object in this plot,
/// or zero if the named object does not exist or is not a RooCurve
 
RooCurve* RooPlot::getCurve(const char* name) const
{
  return dynamic_cast<RooCurve*>(findObject(name)) ;
}
 
 
////////////////////////////////////////////////////////////////////////////////
/// Return a RooCurve pointer of the named object in this plot,
/// or zero if the named object does not exist or is not a RooCurve
 
RooHist* RooPlot::getHist(const char* name) const
{
  return dynamic_cast<RooHist*>(findObject(name)) ;
}
 
 
 
////////////////////////////////////////////////////////////////////////////////
/// Remove object with given name, or last object added if no name is given.
/// If deleteToo is true (default), the object removed from the RooPlot is
/// also deleted.
 
void RooPlot::remove(const char* name, Bool_t deleteToo)
{
  TObject* obj = findObject(name) ;
  if (!obj) {
    if (name) {
      coutE(InputArguments) << "RooPlot::remove(" << GetName() << ") ERROR: no object found with name " << name << endl ;
    } else {
      coutE(InputArguments) << "RooPlot::remove(" << GetName() << ") ERROR: plot frame is empty, cannot remove last object" << endl ;
    }
    return ;
  }
 
  _items.Remove(obj) ;
 
  if (deleteToo) {
    delete obj ;
  }
}
 
 
////////////////////////////////////////////////////////////////////////////////
/// Change the order in which our contained objects are drawn so that
/// the target object is drawn just before the specified object.
/// Returns kFALSE if either object does not exist.
 
Bool_t RooPlot::drawBefore(const char *before, const char *target)
{
  return _items.moveBefore(before, target, caller("drawBefore"));
}
 
 
////////////////////////////////////////////////////////////////////////////////
/// Change the order in which our contained objects are drawn so that
/// the target object is drawn just after the specified object.
/// Returns kFALSE if either object does not exist.
 
Bool_t RooPlot::drawAfter(const char *after, const char *target)
{
  return _items.moveAfter(after, target, caller("drawAfter"));
}
 
 
////////////////////////////////////////////////////////////////////////////////
/// Find the named object in our list of items and return a pointer
/// to it. Return zero and print a warning message if the named
/// object cannot be found. If no name is supplied the last object
/// added is returned.
///
/// Note that the returned pointer is to a
/// TObject and so will generally need casting. Use the getAtt...()
/// methods to change the drawing style attributes of a contained
/// object directly.
 
TObject *RooPlot::findObject(const char *name, const TClass* clas) const
{
  TObject *obj = 0;
  TObject *ret = 0;
 
  TIterator* iter = _items.MakeIterator() ;
  while((obj=iter->Next())) {
    if ((!name || !TString(name).CompareTo(obj->GetName())) &&
   (!clas || (obj->IsA()==clas))) {
      ret = obj ;
    }
  }
  delete iter ;
 
  if (ret==0) {
    coutE(InputArguments) << "RooPlot::findObject(" << GetName() << ") cannot find object " << (name?name:"<last>") << endl ;
  }
  return ret ;
}
 
 
////////////////////////////////////////////////////////////////////////////////
/// Return the Draw() options registered for the named object. Return
/// an empty string if the named object cannot be found.
 
TString RooPlot::getDrawOptions(const char *name) const
{
  TObjOptLink *link= _items.findLink(name,caller("getDrawOptions"));
  DrawOpt opt(0 == link ? "" : link->GetOption()) ;
  return TString(opt.drawOptions) ;
}
 
 
////////////////////////////////////////////////////////////////////////////////
/// Register the specified drawing options for the named object.
/// Return kFALSE if the named object cannot be found.
 
Bool_t RooPlot::setDrawOptions(const char *name, TString options)
{
  TObjOptLink *link= _items.findLink(name,caller("setDrawOptions"));
  if(0 == link) return kFALSE;
 
  DrawOpt opt(link->GetOption()) ;
  strlcpy(opt.drawOptions,options,128) ;
  link->SetOption(opt.rawOpt());
  return kTRUE;
}
 
 
////////////////////////////////////////////////////////////////////////////////
/// Returns true of object with given name is set to be invisible
 
Bool_t RooPlot::getInvisible(const char* name) const
{
  TObjOptLink *link= _items.findLink(name,caller("getInvisible"));
  if(0 == link) return kFALSE;
 
  return DrawOpt(link->GetOption()).invisible ;
}
 
 
////////////////////////////////////////////////////////////////////////////////
/// If flag is true object with 'name' is set to be invisible
/// i.e. it is not drawn when Draw() is called
 
void RooPlot::setInvisible(const char* name, Bool_t flag)
{
  TObjOptLink *link= _items.findLink(name,caller("getInvisible"));
 
  DrawOpt opt ;
 
  if(link) {
    opt.initialize(link->GetOption()) ;
    opt.invisible = flag ;
    link->SetOption(opt.rawOpt()) ;
  }
 
}
 
 
 
////////////////////////////////////////////////////////////////////////////////
/// Utility function
 
TString RooPlot::caller(const char *method) const
{
  TString name(fName);
  if(strlen(method)) {
    name.Append("::");
    name.Append(method);
  }
  return name;
}
 
 
 
////////////////////////////////////////////////////////////////////////////////
/// Set maximum value of Y axis
 
void RooPlot::SetMaximum(Double_t maximum)
{
  _hist->SetMaximum(maximum==-1111?_defYmax:maximum) ;
}
 
 
 
////////////////////////////////////////////////////////////////////////////////
/// Set minimum value of Y axis
 
void RooPlot::SetMinimum(Double_t minimum)
{
  _hist->SetMinimum(minimum==-1111?_defYmin:minimum) ;
}
 
 
 
////////////////////////////////////////////////////////////////////////////////
/// Calculate and return reduced chi-squared of curve with given name with respect
/// to histogram with given name.
///
/// \param[in] curvename  Name of the curve or nullptr for last curve
/// \param[in] histname   Name of the histogram to compare to or nullptr for last added histogram
/// \param[in] nFitParam  If non-zero, reduce the number of degrees of freedom by this
/// number. This means that the curve was fitted to the data with nFitParam floating
/// parameters, which needs to be reflected in the calculation of \f$\chi^2 / \mathrm{ndf}\f$.
/// 
/// \return \f$ \chi^2 / \mathrm{ndf} \f$
 
Double_t RooPlot::chiSquare(const char* curvename, const char* histname, int nFitParam) const
{
 
  // Find curve object
  RooCurve* curve = (RooCurve*) findObject(curvename,RooCurve::Class()) ;
  if (!curve) {
    coutE(InputArguments) << "RooPlot::chiSquare(" << GetName() << ") cannot find curve" << endl ;
    return -1. ;
  }
 
  // Find histogram object
  RooHist* hist = (RooHist*) findObject(histname,RooHist::Class()) ;
  if (!hist) {
    coutE(InputArguments) << "RooPlot::chiSquare(" << GetName() << ") cannot find histogram" << endl ;
    return -1. ;
  }
 
  return curve->chiSquare(*hist,nFitParam) ;
}
 
 
////////////////////////////////////////////////////////////////////////////////
/// Return a RooHist containing the residuals of histogram 'histname' with respect
/// to curve 'curvename'. If normalize is true the residuals are divided by the error
/// on the histogram, effectively returning a pull histogram
 
RooHist* RooPlot::residHist(const char* histname, const char* curvename, bool normalize, bool useAverage) const
{
  // Find curve object
  RooCurve* curve = (RooCurve*) findObject(curvename,RooCurve::Class()) ;
  if (!curve) {
    coutE(InputArguments) << "RooPlot::residHist(" << GetName() << ") cannot find curve" << endl ;
    return 0 ;
  }
 
  // Find histogram object
  RooHist* hist = (RooHist*) findObject(histname,RooHist::Class()) ;
  if (!hist) {
    coutE(InputArguments) << "RooPlot::residHist(" << GetName() << ") cannot find histogram" << endl ;
    return 0 ;
  }
 
  return hist->makeResidHist(*curve,normalize,useAverage) ;
}
 
 
 
////////////////////////////////////////////////////////////////////////////////
/// Initialize the DrawOpt helper class
 
void RooPlot::DrawOpt::initialize(const char* inRawOpt)
{
  if (!inRawOpt) {
    drawOptions[0] = 0 ;
    invisible=kFALSE ;
    return ;
  }
  strlcpy(drawOptions,inRawOpt,128) ;
  strtok(drawOptions,":") ;
  const char* extraOpt = strtok(0,":") ;
  if (extraOpt) {
    invisible =  (extraOpt[0]=='I') ;
  }
}
 
 
////////////////////////////////////////////////////////////////////////////////
/// Return the raw draw options
 
const char* RooPlot::DrawOpt::rawOpt() const
{
  static char buf[128] ;
  strlcpy(buf,drawOptions,128) ;
  if (invisible) {
    strlcat(buf,":I",128) ;
  }
  return buf ;
}
 
 
 
////////////////////////////////////////////////////////////////////////////////
/// Return the number of events that is associated with the range [xlo,xhi]
/// This method is only fully functional for ranges not equal to the full
/// range if the object that inserted the normalization data provided
/// a link to an external object that can calculate the event count in
/// in sub ranges. An error will be printed if this function is used
/// on sub-ranges while that information is not available
 
Double_t RooPlot::getFitRangeNEvt(Double_t xlo, Double_t xhi) const
{
  Double_t scaleFactor = 1.0 ;
  if (_normObj) {
    scaleFactor = _normObj->getFitRangeNEvt(xlo,xhi)/_normObj->getFitRangeNEvt() ;
  } else {
    coutW(Plotting) << "RooPlot::getFitRangeNEvt(" << GetName() << ") WARNING: Unable to obtain event count in range "
          << xlo << " to " << xhi << ", substituting full event count" << endl ;
  }
  return getFitRangeNEvt()*scaleFactor ;
}
 
 
////////////////////////////////////////////////////////////////////////////////
/// Set the name of the RooPlot to 'name'
 
void RooPlot::SetName(const char *name)
{
  if (_dir) _dir->GetList()->Remove(this);
  TNamed::SetName(name) ;
  if (_dir) _dir->GetList()->Add(this);
}
 
 
////////////////////////////////////////////////////////////////////////////////
/// Set the name and title of the RooPlot to 'name' and 'title'
 
void RooPlot::SetNameTitle(const char *name, const char* title)
{
  if (_dir) _dir->GetList()->Remove(this);
  TNamed::SetNameTitle(name,title) ;
  if (_dir) _dir->GetList()->Add(this);
}
 
 
////////////////////////////////////////////////////////////////////////////////
/// Set the title of the RooPlot to 'title'
 
void RooPlot::SetTitle(const char* title)
{
  TNamed::SetTitle(title) ;
  _hist->SetTitle(title) ;
}
 
 
 
////////////////////////////////////////////////////////////////////////////////
/// Define default print options, for a given print style
 
Int_t RooPlot::defaultPrintContents(Option_t* /*opt*/) const
{
  return kName|kArgs|kValue ;
}
 
 
 
TAxis* RooPlot::GetXaxis() const { return _hist->GetXaxis() ; }
TAxis* RooPlot::GetYaxis() const { return _hist->GetYaxis() ; }
Int_t  RooPlot::GetNbinsX() const { return _hist->GetNbinsX() ; }
Int_t  RooPlot::GetNdivisions(Option_t* axis) const { return _hist->GetNdivisions(axis) ; }
Double_t  RooPlot::GetMinimum(Double_t minval) const { return _hist->GetMinimum(minval) ; }
Double_t   RooPlot::GetMaximum(Double_t maxval) const { return _hist->GetMaximum(maxval) ; }
 
 
void RooPlot::SetAxisColor(Color_t color, Option_t* axis) { _hist->SetAxisColor(color,axis) ; }
void RooPlot::SetAxisRange(Double_t xmin, Double_t xmax, Option_t* axis) { _hist->SetAxisRange(xmin,xmax,axis) ; }
void RooPlot::SetBarOffset(Float_t offset) { _hist->SetBarOffset(offset) ; }
void RooPlot::SetBarWidth(Float_t width) { _hist->SetBarWidth(width) ; }
void RooPlot::SetContour(Int_t nlevels, const Double_t* levels) { _hist->SetContour(nlevels,levels) ; }
void RooPlot::SetContourLevel(Int_t level, Double_t value) { _hist->SetContourLevel(level,value) ; }
void RooPlot::SetDrawOption(Option_t* option) { _hist->SetDrawOption(option) ; }
void RooPlot::SetFillAttributes() { _hist->SetFillAttributes() ; }
void RooPlot::SetFillColor(Color_t fcolor) { _hist->SetFillColor(fcolor) ; }
void RooPlot::SetFillStyle(Style_t fstyle) { _hist->SetFillStyle(fstyle) ; }
void RooPlot::SetLabelColor(Color_t color, Option_t* axis) { _hist->SetLabelColor(color,axis) ; }
void RooPlot::SetLabelFont(Style_t font, Option_t* axis) { _hist->SetLabelFont(font,axis) ; }
void RooPlot::SetLabelOffset(Float_t offset, Option_t* axis) { _hist->SetLabelOffset(offset,axis) ; }
void RooPlot::SetLabelSize(Float_t size, Option_t* axis) { _hist->SetLabelSize(size,axis) ; }
void RooPlot::SetLineAttributes() { _hist->SetLineAttributes() ; }
void RooPlot::SetLineColor(Color_t lcolor) { _hist->SetLineColor(lcolor) ; }
void RooPlot::SetLineStyle(Style_t lstyle) { _hist->SetLineStyle(lstyle) ; }
void RooPlot::SetLineWidth(Width_t lwidth) { _hist->SetLineWidth(lwidth) ; }
void RooPlot::SetMarkerAttributes() { _hist->SetMarkerAttributes() ; }
void RooPlot::SetMarkerColor(Color_t tcolor) { _hist->SetMarkerColor(tcolor) ; }
void RooPlot::SetMarkerSize(Size_t msize) { _hist->SetMarkerSize(msize) ; }
void RooPlot::SetMarkerStyle(Style_t mstyle) { _hist->SetMarkerStyle(mstyle) ; }
void RooPlot::SetNdivisions(Int_t n, Option_t* axis) { _hist->SetNdivisions(n,axis) ; }
void RooPlot::SetOption(Option_t* option) { _hist->SetOption(option) ; }
void RooPlot::SetStats(Bool_t stats) { _hist->SetStats(stats) ; }
void RooPlot::SetTickLength(Float_t length, Option_t* axis) { _hist->SetTickLength(length,axis) ; }
void RooPlot::SetTitleFont(Style_t font, Option_t* axis) { _hist->SetTitleFont(font,axis) ; }
void RooPlot::SetTitleOffset(Float_t offset, Option_t* axis) { _hist->SetTitleOffset(offset,axis) ; }
void RooPlot::SetTitleSize(Float_t size, Option_t* axis) { _hist->SetTitleSize(size,axis) ; }
void RooPlot::SetXTitle(const char *title) { _hist->SetXTitle(title) ; }
void RooPlot::SetYTitle(const char *title) { _hist->SetYTitle(title) ; }
void RooPlot::SetZTitle(const char *title) { _hist->SetZTitle(title) ; }
 
 
 
 
////////////////////////////////////////////////////////////////////////////////
/// Plot RooPlot when double-clicked in browser
 
void RooPlot::Browse(TBrowser * /*b*/)
{
  Draw();
  gPad->Update();
}
 
 
 
 
////////////////////////////////////////////////////////////////////////////////
 
void RooPlot::Streamer(TBuffer &R__b)
{
  // Custom streamer, needed for backward compatibility
 
  if (R__b.IsReading()) {
 
    TH1::AddDirectory(kFALSE) ;
 
    // The default c'tor might have registered this with a TDirectory.
    // Streaming the TNamed will make this not retrievable anymore, so
    // unregister first.
    if (_dir)
      _dir->Remove(this);
 
    UInt_t R__s, R__c;
    Version_t R__v = R__b.ReadVersion(&R__s, &R__c);
    if (R__v > 1) {
      R__b.ReadClassBuffer(RooPlot::Class(),this,R__v,R__s,R__c);
    } else {
      // backward compatible streamer code here
      // Version 1 of RooPlot was deriving from TH1 and RooPrintable
      // Version 2 derives instead from TNamed and RooPrintable
      _hist = new TH1F();
      _hist->TH1::Streamer(R__b);
      SetName(_hist->GetName());
      SetTitle(_hist->GetTitle());
      RooPrintable::Streamer(R__b);
      _items.Streamer(R__b);
      R__b >> _padFactor;
      R__b >> _plotVarClone;
      R__b >> _plotVarSet;
      R__b >> _normVars;
      R__b >> _normNumEvts;
      R__b >> _normBinWidth;
      R__b >> _defYmin;
      R__b >> _defYmax;
      R__b.CheckByteCount(R__s, R__c, RooPlot::IsA());
    }
 
    TH1::AddDirectory(kTRUE) ;
    if (_dir)
      _dir->Append(this);
 
  } else {
    R__b.WriteClassBuffer(RooPlot::Class(),this);
  }
}
 
////////////////////////////////////////////////////////////////////////////////
/// Build a legend that contains all objects that have been drawn on the plot.
std::unique_ptr<TLegend> RooPlot::BuildLegend() const {
  std::unique_ptr<TLegend> leg(new TLegend(0.5, 0.7, 0.9, 0.9));
  leg->SetBorderSize(0);
  leg->SetFillStyle(0);
  for (int i=0; i < _items.GetSize(); ++i) {
    leg->AddEntry(getObject(i));
  }
 
  return leg;
}