HistFactoryNavigation.cxx

Go to the documentation of this file.

 
/** \class RooStats::HistFactory::HistFactoryNavigation
 *  \ingroup HistFactory 
 */
 
#include <iomanip>
#include <sstream>
 
#include "TFile.h"
#include "TRegexp.h"
#include "TCanvas.h"
#include "TLegend.h"
#include "TMath.h"
 
#include "RooRealSumPdf.h"
#include "RooProduct.h"
#include "RooMsgService.h"
#include "RooCategory.h"
#include "RooSimultaneous.h"
#include "RooWorkspace.h"
 
#include "RooStats/ModelConfig.h"
#include "RooStats/HistFactory/HistFactoryNavigation.h"
#include "RooStats/HistFactory/HistFactoryException.h"
 
 
ClassImp(RooStats::HistFactory::HistFactoryNavigation);
 
 
namespace RooStats {
  namespace HistFactory {
 
 
    // CONSTRUCTOR
    HistFactoryNavigation::HistFactoryNavigation(ModelConfig* mc) 
      : _minBinToPrint(-1), _maxBinToPrint(-1), 
   _label_print_width(20), _bin_print_width(12) {
 
      if( !mc ) {
   std::cout << "Error: The supplied ModelConfig is NULL " << std::endl;
   throw hf_exc();
      }
 
      // Save the model pointer
      RooAbsPdf* pdf_in_mc = mc->GetPdf();
      if( !pdf_in_mc ) {
   std::cout << "Error: The pdf found in the ModelConfig: " << mc->GetName()
        << " is NULL" << std::endl;
   throw hf_exc();
      }
 
      // Set the PDF member
      fModel = mc->GetPdf();
 
      // Get the observables
      RooArgSet* observables_in_mc = const_cast<RooArgSet*>(mc->GetObservables());
      if( !observables_in_mc ) {
   std::cout << "Error: Observable set in the ModelConfig: " << mc->GetName()
        << " is NULL" << std::endl;
   throw hf_exc();
      }
      if( observables_in_mc->getSize() == 0 ) {
   std::cout << "Error: Observable list: " << observables_in_mc->GetName()
        << " found in ModelConfig: " << mc->GetName()
        << " has no entries." << std::endl;
   throw hf_exc();
      }
 
      // Set the observables member
      fObservables = observables_in_mc;
      
      // Initialize the rest of the members
      _GetNodes(fModel, fObservables);
 
    }
 
 
    // CONSTRUCTOR
    HistFactoryNavigation::HistFactoryNavigation(const std::string& FileName,
                   const std::string& WorkspaceName,
                   const std::string& ModelConfigName) :
      _minBinToPrint(-1), _maxBinToPrint(-1), 
      _label_print_width(20), _bin_print_width(12) {
      
      // Open the File
      TFile* file = new TFile(FileName.c_str());
      if( !file ) {
   std::cout << "Error: Failed to open file: " << FileName << std::endl;
   throw hf_exc();
      }
 
      // Get the workspace
      RooWorkspace* wspace = (RooWorkspace*) file->Get(WorkspaceName.c_str());
      if( !wspace ) {
   std::cout << "Error: Failed to get workspace: " << WorkspaceName
        << " from file: " << FileName << std::endl;
   throw hf_exc();
      }
 
      // Get the ModelConfig
      ModelConfig* mc = (ModelConfig*) wspace->obj(ModelConfigName.c_str());
      if( !mc ) {
   std::cout << "Error: Failed to find ModelConfig: " << ModelConfigName
        << " from workspace: " << WorkspaceName
        << " in file: " << FileName << std::endl;
   throw hf_exc();
      }
 
      // Save the model pointer
      RooAbsPdf* pdf_in_mc = mc->GetPdf();
      if( !pdf_in_mc ) {
   std::cout << "Error: The pdf found in the ModelConfig: " << ModelConfigName
        << " is NULL" << std::endl;
   throw hf_exc();
      }
 
      // Set the PDF member
      fModel = pdf_in_mc;
 
      // Get the observables
      RooArgSet* observables_in_mc = const_cast<RooArgSet*>(mc->GetObservables());
      if( !observables_in_mc ) {
   std::cout << "Error: Observable set in the ModelConfig: " << ModelConfigName
        << " is NULL" << std::endl;
   throw hf_exc();
      }
      if( observables_in_mc->getSize() == 0 ) {
   std::cout << "Error: Observable list: " << observables_in_mc->GetName()
        << " found in ModelConfig: " << ModelConfigName
        << " in file: " << FileName
        << " has no entries." << std::endl;
   throw hf_exc();
      }
 
      // Set the observables member
      fObservables = observables_in_mc;
      
      // Initialize the rest of the members
      _GetNodes(fModel, fObservables);
 
    }
 
 
    // CONSTRUCTOR
    HistFactoryNavigation::HistFactoryNavigation(RooAbsPdf* model, RooArgSet* observables) :
      _minBinToPrint(-1), _maxBinToPrint(-1), 
      _label_print_width(20), _bin_print_width(12) {
 
      // Save the model pointer
      if( !model ) {
   std::cout << "Error: The supplied pdf is NULL" << std::endl;
   throw hf_exc();
      }
 
      // Set the PDF member
      fModel = model;
      fObservables = observables; 
 
      // Get the observables
      if( !observables ) {
   std::cout << "Error: Supplied Observable set is NULL" << std::endl;
   throw hf_exc();
      }
      if( observables->getSize() == 0 ) {
   std::cout << "Error: Observable list: " << observables->GetName()
        << " has no entries." << std::endl;
   throw hf_exc();
      }
 
      // Initialize the rest of the members
      _GetNodes(fModel, fObservables);
 
    }
 
 
    void HistFactoryNavigation::PrintMultiDimHist(TH1* hist, int bin_print_width) {
 
      // This is how ROOT makes us loop over histograms :(
      int current_bin = 0;
      int num_bins = hist->GetNbinsX()*hist->GetNbinsY()*hist->GetNbinsZ();
      for(int i = 0; i < num_bins; ++i) {
   // Avoid the overflow/underflow
   current_bin++;
   while( hist->IsBinUnderflow(current_bin) ||
          hist->IsBinOverflow(current_bin) ) {
     current_bin++;
   }
   // Check that we should print this bin
   if( _minBinToPrint != -1 && i < _minBinToPrint) continue;
   if( _maxBinToPrint != -1 && i > _maxBinToPrint) break;
   std::cout << std::setw(bin_print_width) << hist->GetBinContent(current_bin);
      }
      std::cout << std::endl;
 
    }
 
 
 
    RooAbsPdf* HistFactoryNavigation::GetChannelPdf(const std::string& channel) {
 
      std::map< std::string, RooAbsPdf* >::iterator itr;
      itr = fChannelPdfMap.find(channel);
      
      if( itr == fChannelPdfMap.end() ) {
   std::cout << "Warning: Could not find channel: " << channel
        << " in pdf: " << fModel->GetName() << std::endl;
   return NULL;
      }
      
      RooAbsPdf* pdf = itr->second;
      if( pdf == NULL ) {
   std::cout << "Warning: Pdf associated with channel: " << channel
        << " is NULL" << std::endl;
   return NULL;
      }
 
      return pdf;
 
    }
 
    void HistFactoryNavigation::PrintState(const std::string& channel) {
 
      //int label_print_width = 20;
      //int bin_print_width = 12;
      std::cout << std::endl << channel << ":" << std::endl;
 
      // Get the map of Samples for this channel
      std::map< std::string, RooAbsReal*> SampleFunctionMap = GetSampleFunctionMap(channel);      
 
      // Set the size of the print width if necessary
      /*
      for( std::map< std::string, RooAbsReal*>::iterator itr = SampleFunctionMap.begin(); 
      itr != SampleFunctionMap.end(); ++itr) {
   std::string sample_name = itr->first;
   label_print_width = TMath::Max(label_print_width, (int)sample_name.size()+2);
      }
      */
 
      // Loop over the SampleFunctionMap and print the individual histograms
      // to get the total histogram for the channel
      int num_bins = 0;
      std::map< std::string, RooAbsReal*>::iterator itr = SampleFunctionMap.begin();
      for( ; itr != SampleFunctionMap.end(); ++itr) {
 
   std::string sample_name = itr->first;
   std::string tmp_name = sample_name + channel + "_pretty_tmp";
   TH1* sample_hist = GetSampleHist(channel, sample_name, tmp_name);
   num_bins = sample_hist->GetNbinsX()*sample_hist->GetNbinsY()*sample_hist->GetNbinsZ();
   std::cout << std::setw(_label_print_width) << sample_name;
 
   // Print the content of the histogram
   PrintMultiDimHist(sample_hist, _bin_print_width);
   delete sample_hist;
 
      }
 
      // Make the line break as a set of "===============" ...
      std::string line_break;
      int high_bin = _maxBinToPrint==-1 ? num_bins : TMath::Min(_maxBinToPrint, (int)num_bins);
      int low_bin = _minBinToPrint==-1 ? 1 : _minBinToPrint;
      int break_length = (high_bin - low_bin + 1) * _bin_print_width;
      break_length += _label_print_width;
      for(int i = 0; i < break_length; ++i) {
   line_break += "=";
      }
      std::cout << line_break << std::endl;
 
      std::string tmp_name = channel + "_pretty_tmp";
      TH1* channel_hist = GetChannelHist(channel, tmp_name);
      std::cout << std::setw(_label_print_width) << "TOTAL:";
 
      // Print the Histogram
      PrintMultiDimHist(channel_hist, _bin_print_width);
      delete channel_hist;
 
      return;
 
    }
 
 
    void HistFactoryNavigation::PrintState() {
      // Loop over channels and print their states, one after another
      for(unsigned int i = 0; i < fChannelNameVec.size(); ++i) {
   PrintState(fChannelNameVec.at(i));
      }
    }
 
    
    void HistFactoryNavigation::SetPrintWidths(const std::string& channel) {
 
      // Get the map of Samples for this channel
      std::map< std::string, RooAbsReal*> SampleFunctionMap = GetSampleFunctionMap(channel);      
 
      // Get the max of the samples
      for( std::map< std::string, RooAbsReal*>::iterator itr = SampleFunctionMap.begin(); 
      itr != SampleFunctionMap.end(); ++itr) {
   std::string sample_name = itr->first;
   _label_print_width = TMath::Max(_label_print_width, (int)sample_name.size()+2);
      }
 
      _label_print_width = TMath::Max( _label_print_width, (int)channel.size() + 7); 
    }
 
 
    void HistFactoryNavigation::PrintDataSet(RooDataSet* data, 
                    const std::string& channel_to_print) {
      
      // Print the contents of a 'HistFactory' RooDataset
      // These are stored in a somewhat odd way that makes
      // them difficult to inspect for humans.
      // They have the following layout:
      // =====================================================
      // ChannelA      ChannelB     ChannelCat   Weight
      // -----------------------------------------------------
      // bin_1_center   0           ChannelA     bin_1_height
      // bin_2_center   0           ChannelA     bin_2_height
      //      0        bin_1_center ChannelB     bin_1_height
      //      0        bin_2_center ChannelB     bin_2_height
      //                        ...etc...
      // =====================================================
 
      // int label_print_width = 20;
      // int bin_print_width = 12;
 
      // Get the Data Histogram for this channel
      for( unsigned int i_chan=0; i_chan < fChannelNameVec.size(); ++i_chan) {
 
   std::string channel_name = fChannelNameVec.at(i_chan);
 
   // If we pass a channel string, we only print that one channel
   if( channel_to_print != "" && channel_name != channel_to_print) continue;
 
   TH1* data_hist = GetDataHist(data, channel_name, channel_name+"_tmp");
   std::cout << std::setw(_label_print_width) << channel_name + " (data)";
 
   // Print the Histogram
   PrintMultiDimHist(data_hist, _bin_print_width);
   delete data_hist;
      }
    }
 
 
    void HistFactoryNavigation::PrintModelAndData(RooDataSet* data) {
      // Loop over all channels and print model
      // (including all samples) and compare
      // it to the supplied dataset
 
      for( unsigned int i = 0; i < fChannelNameVec.size(); ++i) {
   std::string channel = fChannelNameVec.at(i);
   SetPrintWidths(channel);
   PrintState(channel);
   PrintDataSet(data, channel);
      }
      
      std::cout << std::endl;
 
    }
 
 
    void HistFactoryNavigation::PrintParameters(bool IncludeConstantParams) {
 
      // Get the list of parameters
      RooArgSet* params = fModel->getParameters(*fObservables);
      
      std::cout << std::endl;
 
      // Create the title row
      std::cout << std::setw(30) << "Parameter";
      std::cout << std::setw(15) << "Value"
      << std::setw(15) << "Error Low" 
      << std::setw(15) << "Error High"
      << std::endl;
      
      // Loop over the parameters and print their values, etc
      TIterator* paramItr = params->createIterator();
      RooRealVar* param = NULL;
      while( (param=(RooRealVar*)paramItr->Next()) ) {
 
   if( !IncludeConstantParams && param->isConstant() ) continue;
 
   std::cout << std::setw(30) << param->GetName();
   std::cout << std::setw(15) << param->getVal();
   if( !param->isConstant() ) {
     std::cout << std::setw(15) << param->getErrorLo() << std::setw(15) << param->getErrorHi();
   }
   std::cout<< std::endl;
      }
      
      std::cout << std::endl;
 
      return;
    }
 
    void HistFactoryNavigation::PrintChannelParameters(const std::string& channel,
                         bool IncludeConstantParams) {
 
      // Get the list of parameters
      RooArgSet* params = fModel->getParameters(*fObservables);
 
      // Get the pdf for this channel
      RooAbsPdf* channel_pdf = GetChannelPdf(channel);
 
      std::cout << std::endl;
 
      // Create the title row
      std::cout << std::setw(30) << "Parameter";
      std::cout << std::setw(15) << "Value"
      << std::setw(15) << "Error Low" 
      << std::setw(15) << "Error High"
      << std::endl;
      
      // Loop over the parameters and print their values, etc
      TIterator* paramItr = params->createIterator();
      RooRealVar* param = NULL;
      while( (param=(RooRealVar*)paramItr->Next()) ) {
 
   if( !IncludeConstantParams && param->isConstant() ) continue;
 
   if( findChild(param->GetName(), channel_pdf)==NULL ) continue;
 
   std::cout << std::setw(30) << param->GetName();
   std::cout << std::setw(15) << param->getVal();
   if( !param->isConstant() ) {
     std::cout << std::setw(15) << param->getErrorLo() << std::setw(15) << param->getErrorHi();
   }
   std::cout<< std::endl;
      }
      
      std::cout << std::endl;
 
      return;
    }
 
 
    void HistFactoryNavigation::PrintSampleParameters(const std::string& channel,
                        const std::string& sample,
                        bool IncludeConstantParams) {
 
      // Get the list of parameters
      RooArgSet* params = fModel->getParameters(*fObservables);
 
      // Get the pdf for this channel
      RooAbsReal* sample_func = SampleFunction(channel, sample);
      
      std::cout << std::endl;
 
      // Create the title row
      std::cout << std::setw(30) << "Parameter";
      std::cout << std::setw(15) << "Value"
      << std::setw(15) << "Error Low" 
      << std::setw(15) << "Error High"
      << std::endl;
      
      // Loop over the parameters and print their values, etc
      TIterator* paramItr = params->createIterator();
      RooRealVar* param = NULL;
      while( (param=(RooRealVar*)paramItr->Next()) ) {
 
   if( !IncludeConstantParams && param->isConstant() ) continue;
 
   if( findChild(param->GetName(), sample_func)==NULL ) continue;
 
   std::cout << std::setw(30) << param->GetName();
   std::cout << std::setw(15) << param->getVal();
   if( !param->isConstant() ) {
     std::cout << std::setw(15) << param->getErrorLo() << std::setw(15) << param->getErrorHi();
   }
   std::cout<< std::endl;
      }
      
      std::cout << std::endl;
 
      return;
    }
 
 
 
    double HistFactoryNavigation::GetBinValue(int bin, const std::string& channel) {
      // Get the total bin height for the ith bin (ROOT indexing convention)
      // in channel 'channel'
      // (Could be optimized, it uses an intermediate histogram for now...)
      
      // Get the histogram, fetch the bin content, and return
      TH1* channel_hist_tmp = GetChannelHist(channel, (channel+"_tmp").c_str());
      double val = channel_hist_tmp->GetBinContent(bin);
      delete channel_hist_tmp;
      return val;
    }
 
 
    double HistFactoryNavigation::GetBinValue(int bin, const std::string& channel, const std::string& sample){  
      // Get the total bin height for the ith bin (ROOT indexing convention)
      // in channel 'channel'
      // (This will be slow if you plan on looping over it.
      //  Could be optimized, it uses an intermediate histogram for now...)
 
      // Get the histogram, fetch the bin content, and return
      TH1* sample_hist_tmp = GetSampleHist(channel, sample,  (channel+"_tmp").c_str());
      double val = sample_hist_tmp->GetBinContent(bin);
      delete sample_hist_tmp;
      return val;
    }
 
 
    std::map< std::string, RooAbsReal*> HistFactoryNavigation::GetSampleFunctionMap(const std::string& channel) {
      // Get a map of strings to function pointers, 
      // which each function cooresponds to a sample
 
      std::map< std::string, std::map< std::string, RooAbsReal*> >::iterator channel_itr;
      channel_itr = fChannelSampleFunctionMap.find(channel);
      if( channel_itr==fChannelSampleFunctionMap.end() ){
   std::cout << "Error: Channel: " << channel << " not found in Navigation" << std::endl;
   throw hf_exc();
      }
 
      return channel_itr->second;
    }
 
 
    RooAbsReal* HistFactoryNavigation::SampleFunction(const std::string& channel, const std::string& sample){
      // Return the function object pointer cooresponding
      // to a particular sample in a particular channel
 
      std::map< std::string, std::map< std::string, RooAbsReal*> >::iterator channel_itr;
      channel_itr = fChannelSampleFunctionMap.find(channel);
      if( channel_itr==fChannelSampleFunctionMap.end() ){
   std::cout << "Error: Channel: " << channel << " not found in Navigation" << std::endl;
   throw hf_exc();
      }
 
      std::map< std::string, RooAbsReal*>& SampleMap = channel_itr->second;
      std::map< std::string, RooAbsReal*>::iterator sample_itr;
      sample_itr = SampleMap.find(sample);
      if( sample_itr==SampleMap.end() ){
   std::cout << "Error: Sample: " << sample << " not found in Navigation" << std::endl;
   throw hf_exc();
      }
      
      return sample_itr->second;
 
    }
 
 
    RooArgSet* HistFactoryNavigation::GetObservableSet(const std::string& channel) {
      // Get the observables for a particular channel
 
      std::map< std::string, RooArgSet*>::iterator channel_itr;
      channel_itr = fChannelObservMap.find(channel);
      if( channel_itr==fChannelObservMap.end() ){
   std::cout << "Error: Channel: " << channel << " not found in Navigation" << std::endl;
   throw hf_exc();
      }
      
      return channel_itr->second;
 
    }
 
 
    TH1* HistFactoryNavigation::GetSampleHist(const std::string& channel, const std::string& sample,
                     const std::string& hist_name) {
      // Get a histogram of the expected values for
      // a particular sample in a particular channel
      // Give a name, or a default one will be used
 
      RooArgList observable_list( *GetObservableSet(channel) );
      
      std::string name = hist_name;
      if(hist_name=="") name = channel + "_" + sample + "_hist";
 
      RooAbsReal* sample_function = SampleFunction(channel, sample);
 
      return MakeHistFromRooFunction( sample_function, observable_list, name );
                 
    }
 
 
    TH1* HistFactoryNavigation::GetChannelHist(const std::string& channel, const std::string& hist_name) {
      // Get a histogram of the total expected value
      // per bin for this channel
      // Give a name, or a default one will be used
 
      RooArgList observable_list( *GetObservableSet(channel) );
      
      std::map< std::string, RooAbsReal*> SampleFunctionMap = GetSampleFunctionMap(channel);
 
      // Okay, 'loop' once 
      TH1* total_hist=NULL;
      std::map< std::string, RooAbsReal*>::iterator itr = SampleFunctionMap.begin();
      for( ; itr != SampleFunctionMap.end(); ++itr) {
   std::string sample_name = itr->first;
   std::string tmp_hist_name = sample_name + "_hist_tmp";
   RooAbsReal* sample_function = itr->second;
   TH1* sample_hist = MakeHistFromRooFunction(sample_function, observable_list, 
                     tmp_hist_name);
   total_hist = (TH1*) sample_hist->Clone("TotalHist");
   delete sample_hist;
   break;
      }
      total_hist->Reset();
 
      // Loop over the SampleFunctionMap and add up all the histograms
      // to get the total histogram for the channel
      itr = SampleFunctionMap.begin();
      for( ; itr != SampleFunctionMap.end(); ++itr) {
   std::string sample_name = itr->first;
   std::string tmp_hist_name = sample_name + "_hist_tmp";
   RooAbsReal* sample_function = itr->second;
   TH1* sample_hist = MakeHistFromRooFunction(sample_function, observable_list, 
                     tmp_hist_name);
   total_hist->Add(sample_hist);
   delete sample_hist;
      }
 
      if(hist_name=="") total_hist->SetName(hist_name.c_str());
      else total_hist->SetName( (channel + "_hist").c_str() ); 
 
      return total_hist;
 
    }
 
 
    std::vector< std::string > HistFactoryNavigation::GetChannelSampleList(const std::string& channel) {
      
      std::vector<std::string> sample_list;
 
      std::map< std::string, RooAbsReal*> sample_map = fChannelSampleFunctionMap[channel];
      std::map< std::string, RooAbsReal*>::iterator itr = sample_map.begin();;
      for( ; itr != sample_map.end(); ++itr) {
   sample_list.push_back( itr->first );
      }
 
      return sample_list;
 
    }
 
    
    THStack* HistFactoryNavigation::GetChannelStack(const std::string& channel, 
                      const std::string& name) {
    
      THStack* stack = new THStack(name.c_str(), "");
 
      std::vector< std::string > samples = GetChannelSampleList(channel);
 
      // Add the histograms
      for( unsigned int i=0; i < samples.size(); ++i) {
   std::string sample_name = samples.at(i);
   TH1* hist = GetSampleHist(channel, sample_name, sample_name+"_tmp");
   hist->SetLineColor(2+i);
   hist->SetFillColor(2+i);
   stack->Add(hist);
      }
 
      return stack;
 
    }
 
  
    TH1* HistFactoryNavigation::GetDataHist(RooDataSet* data, const std::string& channel, 
                   const std::string& name) {
                   
      // TO DO:
      // MAINTAIN THE ACTUAL RANGE, USING THE OBSERVABLES
      // MAKE IT WORK FOR MULTI-DIMENSIONAL
      // 
 
      // If the dataset covers multiple categories,
      // Split the dataset based on the categories
      if(strcmp(fModel->ClassName(),"RooSimultaneous")==0){
 
   // If so, get a list of the component pdf's:
   RooSimultaneous* simPdf = (RooSimultaneous*) fModel;
   RooCategory* channelCat = (RooCategory*) (&simPdf->indexCat());
 
   TList* dataset_list = data->split(*channelCat);
 
   data = dynamic_cast<RooDataSet*>( dataset_list->FindObject(channel.c_str()) );
   
      }
 
      RooArgList vars( *GetObservableSet(channel) );
 
      int dim = vars.getSize();
 
      TH1* hist = NULL;
 
      if( dim==1 ) {
   RooRealVar* varX = (RooRealVar*) vars.at(0);
   hist = data->createHistogram( name.c_str(),*varX, RooFit::Binning(varX->getBinning()) );
      }
      else if( dim==2 ) {
   RooRealVar* varX = (RooRealVar*) vars.at(0);
   RooRealVar* varY = (RooRealVar*) vars.at(1);
   hist = data->createHistogram( name.c_str(),*varX, RooFit::Binning(varX->getBinning()),
                  RooFit::YVar(*varY, RooFit::Binning(varY->getBinning())) );
      }
      else if( dim==3 ) {
   RooRealVar* varX = (RooRealVar*) vars.at(0);
   RooRealVar* varY = (RooRealVar*) vars.at(1);
   RooRealVar* varZ = (RooRealVar*) vars.at(2);
   hist = data->createHistogram( name.c_str(),*varX, RooFit::Binning(varX->getBinning()), 
                  RooFit::YVar(*varY, RooFit::Binning(varY->getBinning())),
                  RooFit::YVar(*varZ, RooFit::Binning(varZ->getBinning())) );
      }
      else {
   std::cout << "Error: To Create Histogram from RooDataSet, Dimension must be 1, 2, or 3" << std::endl;
   std::cout << "Observables: " << std::endl;
   vars.Print("V");
   throw hf_exc();
      }
 
      return hist;
 
    }
 
 
    void HistFactoryNavigation::DrawChannel(const std::string& channel, RooDataSet* data) {
    
      // Get the stack
      THStack* stack = GetChannelStack(channel, channel+"_stack_tmp");
 
      stack->Draw();
      
      if( data!=NULL ) {
   TH1* data_hist = GetDataHist(data, channel, channel+"_data_tmp");
   data_hist->Draw("SAME");
      }
 
    }
  
 
 
    RooArgSet HistFactoryNavigation::_GetAllProducts(RooProduct* node) {
 
      // An internal method to recursively get all products,
      // including if a RooProduct is a Product of RooProducts
      // etc
 
      RooArgSet allTerms;
 
      // Get All Subnodes of this product
      RooArgSet productComponents = node->components();
      
      // Loop over the subnodes and add
      TIterator* itr = productComponents.createIterator();
      RooAbsArg* arg = NULL;
      while( (arg=(RooAbsArg*)itr->Next()) ) {
   std::string ClassName = arg->ClassName();
   if( ClassName == "RooProduct" ) {
     RooProduct* prod = dynamic_cast<RooProduct*>(arg);
     allTerms.add( _GetAllProducts(prod) );
   }
   else {
     allTerms.add(*arg);
   }
      }
      delete itr;
 
      return allTerms;
 
    }
 
 
 
 
    void HistFactoryNavigation::_GetNodes(RooAbsPdf* modelPdf, const RooArgSet* observables) {
 
      // Get the pdf from the ModelConfig
      //RooAbsPdf* modelPdf = mc->GetPdf();
      //RooArgSet* observables = mc->GetObservables();
 
      // Create vectors to hold the channel pdf's
      // as well as the set of observables for each channel
      //std::map< std::string, RooAbsPdf* >  channelPdfMap;
      //std::map< std::string, RooArgSet* >  channelObservMap;
      
      // Check if it is a simultaneous pdf or not
      // (if it's an individual channel, it won't be, if it's
      // combined, it's simultaneous)
      // Fill the channel vectors based on the structure
      // (Obviously, if it's not simultaneous, there will be
      // only one entry in the vector for the single channel)
      if(strcmp(modelPdf->ClassName(),"RooSimultaneous")==0){
 
   // If so, get a list of the component pdf's:
   RooSimultaneous* simPdf = (RooSimultaneous*) modelPdf;
   RooCategory* channelCat = (RooCategory*) (&simPdf->indexCat());
 
   // Iterate over the categories and get the
   // pdf and observables for each category
   TIterator* iter = channelCat->typeIterator() ;
   RooCatType* tt = NULL;
        while((tt=(RooCatType*) iter->Next())) {
     std::string ChannelName = tt->GetName();
     fChannelNameVec.push_back( ChannelName );
     RooAbsPdf* pdftmp = simPdf->getPdf(ChannelName.c_str()) ;
     RooArgSet* obstmp = pdftmp->getObservables(*observables) ;
     fChannelPdfMap[ChannelName] = pdftmp;
     fChannelObservMap[ChannelName] =  obstmp;
   }
 
      } else { 
   RooArgSet* obstmp = modelPdf->getObservables(*observables) ;   
   // The channel name is model_CHANNEL
   std::string ChannelName = modelPdf->GetName();
   ChannelName = ChannelName.replace(0, 6, "");
   fChannelNameVec.push_back(ChannelName);
   fChannelPdfMap[ChannelName] = modelPdf;
   fChannelObservMap[ChannelName] = obstmp;
 
      }
 
      // Okay, now we have maps of the pdfs 
      // and the observable list per channel
      // We then loop over the channel pdfs:
      // and find their RooRealSumPdfs
      // std::map< std::string, RooRealSumPdf* > channelSumNodeMap;
 
      for( unsigned int i = 0; i < fChannelNameVec.size(); ++i ) {
 
   std::string ChannelName = fChannelNameVec.at(i);
   RooAbsPdf* pdf = fChannelPdfMap[ChannelName];
   //std::string Name = fChannelNameMap[ChannelName];
 
   // Loop over the pdf's components and find
   // the (one) that is a RooRealSumPdf
   // Based on the mode, we assume that node is 
   // the "unconstrained" pdf node for that channel
   RooArgSet* components = pdf->getComponents();
   TIterator* argItr = components->createIterator();
   RooAbsArg* arg = NULL;
   while( (arg=(RooAbsArg*)argItr->Next()) ) {
     std::string ClassName = arg->ClassName();
     if( ClassName == "RooRealSumPdf" ) {
       fChannelSumNodeMap[ChannelName] = (RooRealSumPdf*) arg;
       break;
     }
   }
      }
      
      // Okay, now we have all necessary
      // nodes filled for each channel.
      for( unsigned int i = 0; i < fChannelNameVec.size(); ++i ) {
 
   std::string ChannelName = fChannelNameVec.at(i);
   RooRealSumPdf* sumPdf = dynamic_cast<RooRealSumPdf*>(fChannelSumNodeMap[ChannelName]);
   
   // We now take the RooRealSumPdf and loop over
   // its component functions.  The RooRealSumPdf turns
   // a list of functions (expected events or bin heights
   // per sample) and turns it into a pdf.
   // Therefore, we loop over it to find the expected
   // height for the various samples
 
   // First, create a map to store the function nodes
   // for each sample in this channel
   std::map< std::string, RooAbsReal*> sampleFunctionMap;
 
   // Loop over the sample nodes in this
   // channel's RooRealSumPdf
   RooArgList nodes = sumPdf->funcList();
   TIterator* sampleItr = nodes.createIterator();
   RooAbsArg* sample;
   while( (sample=(RooAbsArg*)sampleItr->Next()) ) {
 
     // Cast this node as a function
     RooAbsReal* func = (RooAbsReal*) sample;
 
     // Do a bit of work to get the name of each sample
     std::string SampleName = sample->GetName();
     if( SampleName.find("L_x_") != std::string::npos ) {
       size_t index = SampleName.find("L_x_");
       SampleName.replace( index, 4, "" );
     }
     if( SampleName.find(ChannelName.c_str()) != std::string::npos ) {
       size_t index = SampleName.find(ChannelName.c_str());
       SampleName = SampleName.substr(0, index-1);
     }
 
     // And simply save this node into our map
     sampleFunctionMap[SampleName] = func;
 
   }
 
   fChannelSampleFunctionMap[ChannelName] = sampleFunctionMap;
 
   // Okay, now we have a list of histograms
   // representing the samples for this channel.
 
      }
 
    }
 
 
    RooAbsArg* HistFactoryNavigation::findChild(const std::string& name, RooAbsReal* parent) const {
      
      RooAbsArg* term=NULL;
 
      // Check if it is a "component",
      // ie a sub node:
      RooArgSet* components = parent->getComponents();
      TIterator* argItr = components->createIterator();
      RooAbsArg* arg = NULL;
      while( (arg=(RooAbsArg*)argItr->Next()) ) {
   std::string ArgName = arg->GetName();
   if( ArgName == name ) {
     term = arg; //dynamic_cast<RooAbsReal*>(arg);
     break;
   }
      }
      delete components;
      delete argItr;
 
      if( term != NULL ) return term;
 
      // If that failed, 
      // Check if it's a Parameter
      // (ie a RooRealVar)
      RooArgSet* args = new RooArgSet();
      RooArgSet* paramSet = parent->getParameters(args);
      TIterator* paramItr = paramSet->createIterator();
      RooAbsArg* param = NULL;
      while( (param=(RooAbsArg*)paramItr->Next()) ) {
   std::string ParamName = param->GetName();
   if( ParamName == name ) {
     term = param; //dynamic_cast<RooAbsReal*>(arg);
     break;
   }
      }
      delete args;
      delete paramSet;
      delete paramItr;
 
      /* Not sure if we want to be silent
    But since we're returning a pointer which can be NULL,
    I think it's the user's job to do checks on it.
    A dereference will always cause a crash, so it won't
    be silent for long...
    if( term==NULL ) {
    std::cout << "Error: Failed to find node: " << name
    << " as a child of: " << parent->GetName()
    << std::endl;
    }
      */
 
      return term;
 
    }
 
 
    RooAbsReal* HistFactoryNavigation::GetConstraintTerm(const std::string& parameter) {
     
      std::string ConstraintTermName = parameter + "Constraint";
 
      // First, as a sanity check, let's see if the parameter
      // itself actually exists and if the model depends on it:
      RooRealVar* param = dynamic_cast<RooRealVar*>(findChild(parameter, fModel));
      if( param==NULL ) {
   std::cout << "Error: Couldn't Find parameter: " << parameter << " in model."
        << std::endl;
   return NULL;
      }
 
      // The "gamma"'s use a different constraint term name
      if( parameter.find("gamma_stat_") != std::string::npos ) { 
   ConstraintTermName = parameter + "_constraint";
      }
 
      // Now, get the constraint itself
      RooAbsReal* term = dynamic_cast<RooAbsReal*>(findChild(ConstraintTermName, fModel));
 
      if( term==NULL ) {
   std::cout << "Error: Couldn't Find constraint term for parameter: " << parameter
        << " (Looked for '" << ConstraintTermName << "')" << std::endl;
   return NULL;
      }
 
      return term;
 
    }
 
 
    double HistFactoryNavigation::GetConstraintUncertainty(const std::string& parameter) {
      
      RooAbsReal* constraintTerm = GetConstraintTerm(parameter);
      if( constraintTerm==NULL ) {
   std::cout << "Error: Cannot get uncertainty because parameter: " << parameter
        << " has no constraint term" << std::endl;
   throw hf_exc();
      }
 
      // Get the type of constraint
      std::string ConstraintType = constraintTerm->IsA()->GetName();
 
      // Find its value
      double sigma = 0.0;
 
      if( ConstraintType == "" ) {
   std::cout << "Error: Constraint type is an empty string."  
        << " This simply should not be." << std::endl;
   throw hf_exc();
      }
      else if( ConstraintType == "RooGaussian" ){
   
   // Gaussian errors are the 'sigma' in the constraint term
 
   // Get the name of the 'sigma' for the gaussian
   // (I don't know of a way of doing RooGaussian::GetSigma() )
   // For alpha's, the sigma points to a global RooConstVar
   // with the name "1"
   // For gamma_stat_*, the sigma is named *_sigma
   std::string sigmaName = "";
   if( parameter.find("alpha_")!=std::string::npos ) {
     sigmaName = "1";;
   }
   else if( parameter.find("gamma_stat_")!=std::string::npos ) {
     sigmaName = parameter + "_sigma";
   }
 
   // Get the sigma and its value
   RooAbsReal* sigmaVar = dynamic_cast<RooAbsReal*>(constraintTerm->findServer(sigmaName.c_str()));
   if( sigmaVar==NULL ) {
     std::cout << "Error: Failed to find the 'sigma' node: " << sigmaName
          << " in the RooGaussian: " << constraintTerm->GetName() << std::endl;
     throw hf_exc();
   }
   // If we find the uncertainty:
   sigma = sigmaVar->getVal();
      }
      else if( ConstraintType == "RooPoisson" ){
   // Poisson errors are given by inverting: tau = 1 / (sigma*sigma)
   std::string tauName = "nom_" + parameter;
   RooAbsReal* tauVar = dynamic_cast<RooAbsReal*>( constraintTerm->findServer(tauName.c_str()) );
   if( tauVar==NULL ) {
     std::cout << "Error: Failed to find the nominal 'tau' node: " << tauName
          << " for the RooPoisson: " << constraintTerm->GetName() << std::endl;
     throw hf_exc();
   }
   double tau_val = tauVar->getVal();
   sigma = 1.0 / TMath::Sqrt( tau_val );
      } 
      else {
   std::cout << "Error: Encountered unknown constraint type for Stat Uncertainties: " 
        << ConstraintType << std::endl;
   throw hf_exc();
      }
 
      return sigma;
 
    }
 
    void HistFactoryNavigation::ReplaceNode(const std::string& ToReplace, RooAbsArg* ReplaceWith) {
 
      // First, check that the node to replace is actually a node:
      RooAbsArg* nodeToReplace = findChild(ToReplace, fModel);
      if( nodeToReplace==NULL ) {
        std::cout << "Error: Cannot replace node: " << ToReplace
            << " because this node wasn't found in: " << fModel->GetName()
            << std::endl;
        throw hf_exc();
      }
 
      // Now that we have the node we want to replace, we have to 
      // get its parent node
 
      // Do this by looping over the clients and replacing their servers
      // (NOTE: This happens for ALL clients across the pdf)
      for (auto client : nodeToReplace->clients()) {
 
        // Check if this client is a member of our pdf
        // (We probably don't want to mess with clients
        // if they aren't...)
        if( findChild(client->GetName(), fModel) == nullptr) continue;
 
        // Now, do the replacement:
        bool valueProp=false;
        bool shapeProp=false;
        client->replaceServer( *nodeToReplace, *ReplaceWith, valueProp, shapeProp );
        std::cout << "Replaced: " << ToReplace << " with: " << ReplaceWith->GetName()
                << " in node: " << client->GetName() << std::endl;
 
      }
 
      return;
 
    }
 
 
    void HistFactoryNavigation::PrintSampleComponents(const std::string& channel, 
                        const std::string& sample) {
      
      // Get the Sample Node
      RooAbsReal* sampleNode = SampleFunction(channel, sample);
 
      // Get the observables for this channel
      RooArgList observable_list( *GetObservableSet(channel) );
 
      // Make the total histogram for this sample
      std::string total_Name = sampleNode->GetName();
      TH1* total_hist= MakeHistFromRooFunction( sampleNode, observable_list, total_Name + "_tmp");
      unsigned int num_bins = total_hist->GetNbinsX()*total_hist->GetNbinsY()*total_hist->GetNbinsZ();
 
      RooArgSet components;
      
      // Let's see what it is...
      int label_print_width = 30;  
      int bin_print_width = 12;
      if( strcmp(sampleNode->ClassName(),"RooProduct")==0){
   RooProduct* prod = dynamic_cast<RooProduct*>(sampleNode);
   components.add( _GetAllProducts(prod) );
      }
      else {
   components.add(*sampleNode);
      }
      
      /////// NODE SIZE
      {
   TIterator* itr = components.createIterator();
   RooAbsArg* arg = NULL;
   while( (arg=(RooAbsArg*)itr->Next()) ) {
     RooAbsReal* component = dynamic_cast<RooAbsReal*>(arg);
     std::string NodeName = component->GetName();
     label_print_width = TMath::Max(label_print_width, (int)NodeName.size()+2);
   }
      }
 
      // Now, loop over the components and print them out:
      std::cout << std::endl;
      std::cout << "Channel: " << channel << " Sample: " << sample << std::endl;
      std::cout << std::setw(label_print_width) << "Factor";
 
      for(unsigned int i=0; i < num_bins; ++i) {
   if( _minBinToPrint != -1 && (int)i < _minBinToPrint) continue;
   if( _maxBinToPrint != -1 && (int)i > _maxBinToPrint) break;
   std::stringstream sstr;
   sstr << "Bin" << i;
   std::cout << std::setw(bin_print_width) << sstr.str();
      }
      std::cout << std::endl;
 
      TIterator* itr = components.createIterator();
      RooAbsArg* arg = NULL;
      while( (arg=(RooAbsArg*)itr->Next()) ) {
   RooAbsReal* component = dynamic_cast<RooAbsReal*>(arg);
   std::string NodeName = component->GetName();
 
   // Make a histogram for this node   
   // Do some horrible things to prevent some really
   // annoying messages from being printed
   RooFit::MsgLevel levelBefore = RooMsgService::instance().globalKillBelow();
   RooMsgService::instance().setGlobalKillBelow(RooFit::FATAL);
   TH1* hist=NULL;
   try {
     hist = MakeHistFromRooFunction( component, observable_list, NodeName+"_tmp");
   } catch(...) {
     RooMsgService::instance().setGlobalKillBelow(levelBefore);
     throw;
   }
   RooMsgService::instance().setGlobalKillBelow(levelBefore);
 
   // Print the hist
   std::cout << std::setw(label_print_width) << NodeName;
 
   // Print the Histogram
   PrintMultiDimHist(hist, bin_print_width);
   delete hist;
      }
      /////
      std::string line_break;
      int high_bin = _maxBinToPrint==-1 ? num_bins : TMath::Min(_maxBinToPrint, (int)num_bins);
      int low_bin = _minBinToPrint==-1 ? 1 : _minBinToPrint;
      int break_length = (high_bin - low_bin + 1) * bin_print_width;
      break_length += label_print_width;
      for(int i = 0; i < break_length; ++i) {
   line_break += "=";
      }
      std::cout << line_break << std::endl;
 
      std::cout << std::setw(label_print_width) << "TOTAL:";
      PrintMultiDimHist(total_hist, bin_print_width);
      /*
      for(unsigned int i = 0; i < num_bins; ++i) {
   if( _minBinToPrint != -1 && (int)i < _minBinToPrint) continue;
   if( _maxBinToPrint != -1 && (int)i > _maxBinToPrint) break;
   std::cout << std::setw(bin_print_width) << total_hist->GetBinContent(i+1);
      }
      std::cout << std::endl << std::endl;
      */
      delete total_hist;
      
      return;
 
    }
 
 
    TH1* HistFactoryNavigation::MakeHistFromRooFunction( RooAbsReal* func, RooArgList vars, 
                      std::string name ) {
 
      // Turn a RooAbsReal* into a TH1* based 
      // on a template histogram.  
      // The 'vars' arg list defines the x (and y and z variables)
      // Loop over the bins of the Template,
      // find the bin centers, 
      // Scan the input Var over those bin centers,
      // and use the value of the function
      // to make the new histogram
 
      // Make the new histogram
      // Cone and empty the template
      //      TH1* hist = (TH1*) histTemplate.Clone( name.c_str() );
 
      int dim = vars.getSize();
 
      TH1* hist=NULL;
 
      if( dim==1 ) {
   RooRealVar* varX = (RooRealVar*) vars.at(0);
   hist = func->createHistogram( name.c_str(),*varX, RooFit::Binning(varX->getBinning()), RooFit::Scaling(false) );
      }
      else if( dim==2 ) {
   RooRealVar* varX = (RooRealVar*) vars.at(0);
   RooRealVar* varY = (RooRealVar*) vars.at(1);
   hist = func->createHistogram( name.c_str(),*varX, RooFit::Binning(varX->getBinning()), RooFit::Scaling(false),
                  RooFit::YVar(*varY, RooFit::Binning(varY->getBinning())) );
      }
      else if( dim==3 ) {
   RooRealVar* varX = (RooRealVar*) vars.at(0);
   RooRealVar* varY = (RooRealVar*) vars.at(1);
   RooRealVar* varZ = (RooRealVar*) vars.at(2);
   hist = func->createHistogram( name.c_str(),*varX, RooFit::Binning(varX->getBinning()), RooFit::Scaling(false),
                  RooFit::YVar(*varY, RooFit::Binning(varY->getBinning())),
                  RooFit::YVar(*varZ, RooFit::Binning(varZ->getBinning())) );
      }
      else {
   std::cout << "Error: To Create Histogram from RooAbsReal function, Dimension must be 1, 2, or 3" << std::endl;
   throw hf_exc();
      }
 
      return hist;
    }
 
    // A simple wrapper to use a ModelConfig
    void HistFactoryNavigation::_GetNodes(ModelConfig* mc) {
      RooAbsPdf* modelPdf = mc->GetPdf();
      const RooArgSet* observables = mc->GetObservables();
      _GetNodes(modelPdf, observables);
    }
 
 
    void HistFactoryNavigation::SetConstant(const std::string& regExpr, bool constant) {
 
      // Regex FTW
      
      TString RegexTString(regExpr);
      TRegexp theRegExpr(RegexTString);
 
      // Now, loop over all variables and 
      // set the constant as 
 
      // Get the list of parameters
      RooArgSet* params = fModel->getParameters(*fObservables);
      
      std::cout << std::endl;
 
      // Create the title row
      std::cout << std::setw(30) << "Parameter";
      std::cout << std::setw(15) << "Value"
      << std::setw(15) << "Error Low" 
      << std::setw(15) << "Error High"
      << std::endl;
      
      // Loop over the parameters and print their values, etc
      TIterator* paramItr = params->createIterator();
      RooRealVar* param = NULL;
      while( (param=(RooRealVar*)paramItr->Next()) ) {
 
   std::string ParamName = param->GetName();
   TString ParamNameTString(ParamName);
 
   // Use the Regex to skip all parameters that don't match
   //if( theRegExpr.Index(ParamNameTString, ParamName.size()) == -1 ) continue;
   Ssiz_t dummy;
   if( theRegExpr.Index(ParamNameTString, &dummy) == -1 ) continue;
   
   param->setConstant( constant );
   std::cout << "Setting param: " << ParamName << " constant" 
        << " (matches regex: " << regExpr << ")" << std::endl;
      }
    }
 
    RooRealVar* HistFactoryNavigation::var(const std::string& varName) const {
      
      RooAbsArg* arg = findChild(varName, fModel);
      if( !arg ) return NULL;
 
      RooRealVar* var_obj = dynamic_cast<RooRealVar*>(arg);
      return var_obj;
 
    }
 
    /*
      void HistFactoryNavigation::AddChannel(const std::string& channel, RooAbsPdf* pdf, 
      RooDataSet* data=NULL) {
 
      }
    */
 
  } // namespace HistFactory
} // namespace RooStats