HistFactoryNavigation.cxx

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/** \class RooStats::HistFactory::HistFactoryNavigation
 *  \ingroup HistFactory
 */
 
#include <iomanip>
#include <sstream>
 
#include "TFile.h"
#include "TRegexp.h"
#include "TMath.h"
 
#include "RooRealSumPdf.h"
#include "RooProduct.h"
#include "RooMsgService.h"
#include "RooCategory.h"
#include "RooSimultaneous.h"
#include "RooWorkspace.h"
#include "RooFit/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 nullptr " << 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 nullptr" << 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 nullptr" << std::endl;
   throw hf_exc();
      }
      if( observables_in_mc->empty() ) {
   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
      auto file = std::make_unique<TFile>(FileName.c_str());
      if( !file ) {
   std::cout << "Error: Failed to open file: " << FileName << std::endl;
   throw hf_exc();
      }
 
      // Get the workspace
      RooWorkspace* wspace = static_cast<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 = static_cast<ModelConfig*>(wspace->obj(ModelConfigName));
      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 nullptr" << 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 nullptr" << std::endl;
   throw hf_exc();
      }
      if( observables_in_mc->empty() ) {
   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 nullptr" << 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 nullptr" << std::endl;
   throw hf_exc();
      }
      if( observables->empty() ) {
   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 nullptr;
      }
 
      RooAbsPdf* pdf = itr->second;
      if( pdf == nullptr ) {
   std::cout << "Warning: Pdf associated with channel: " << channel
        << " is nullptr" << std::endl;
   return nullptr;
      }
 
      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 = std::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";
   std::unique_ptr<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.get(), _bin_print_width);
 
      }
 
      // Make the line break as a set of "===============" ...
      std::string line_break;
      int high_bin = _maxBinToPrint==-1 ? num_bins : std::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";
      std::unique_ptr<TH1> channel_hist{GetChannelHist(channel, tmp_name)};
      std::cout << std::setw(_label_print_width) << "TOTAL:";
 
      // Print the Histogram
      PrintMultiDimHist(channel_hist.get(), _bin_print_width);
 
      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 = std::max(_label_print_width, (int)sample_name.size()+2);
      }
 
      _label_print_width = std::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.empty() && channel_name != channel_to_print) continue;
 
   std::unique_ptr<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.get(), _bin_print_width);
      }
    }
 
 
    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, params);
 
      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
      for (auto const *param : static_range_cast<RooRealVar *>(params)) {
        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;
    }
 
    void HistFactoryNavigation::PrintChannelParameters(const std::string& channel,
                         bool IncludeConstantParams) {
 
      // Get the list of parameters
      RooArgSet params;
      fModel->getParameters(fObservables, params);
 
      // 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
      for (auto const *param : static_range_cast<RooRealVar *>(params)) {
        if( !IncludeConstantParams && param->isConstant() ) continue;
        if( findChild(param->GetName(), channel_pdf)==nullptr ) 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;
    }
 
 
    void HistFactoryNavigation::PrintSampleParameters(const std::string& channel,
                        const std::string& sample,
                        bool IncludeConstantParams) {
 
      // Get the list of parameters
      RooArgSet params;
      fModel->getParameters(fObservables, params);
 
      // 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
      for (auto const *param : static_range_cast<RooRealVar *>(params)) {
        if( !IncludeConstantParams && param->isConstant() ) continue;
        if( findChild(param->GetName(), sample_func)==nullptr ) 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;
    }
 
 
    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
      std::unique_ptr<TH1> channel_hist_tmp{GetChannelHist(channel, channel+"_tmp")};
      return channel_hist_tmp->GetBinContent(bin);
    }
 
 
    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
      std::unique_ptr<TH1> sample_hist_tmp{GetSampleHist(channel, sample,  channel+"_tmp")};
      return sample_hist_tmp->GetBinContent(bin);
    }
 
 
    std::map< std::string, RooAbsReal*> HistFactoryNavigation::GetSampleFunctionMap(const std::string& channel) {
      // Get a map of strings to function pointers,
      // which each function corresponds 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 corresponding
      // 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.empty()) 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 = nullptr;
      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;
   std::unique_ptr<TH1> sample_hist{MakeHistFromRooFunction(sample_function, observable_list,
                     tmp_hist_name)};
   total_hist = static_cast<TH1*>(sample_hist->Clone("TotalHist"));
   break;
      }
      if (!total_hist)
         return nullptr;
 
      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;
   std::unique_ptr<TH1> sample_hist{MakeHistFromRooFunction(sample_function, observable_list,
                     tmp_hist_name)};
   total_hist->Add(sample_hist.get());
      }
 
      if(hist_name.empty()) 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
      //
 
      std::unique_ptr<TList> dataset_list;
 
      // 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 = static_cast<RooSimultaneous*>(fModel);
   auto channelCat = static_cast<RooCategory const*>(&simPdf->indexCat());
 
   dataset_list = std::unique_ptr<TList>{data->split(*channelCat)};
 
   data = dynamic_cast<RooDataSet*>(dataset_list->FindObject(channel.c_str()) );
 
      }
 
      RooArgList vars( *GetObservableSet(channel) );
 
      int dim = vars.size();
 
      TH1* hist = nullptr;
 
      if (!data) {
   std::cout << "Error: To Create Histogram from RooDataSet" << std::endl;
   if (dataset_list) {
      dataset_list.reset();
   }
        throw hf_exc();
      } else if( dim==1 ) {
   RooRealVar* varX = static_cast<RooRealVar*>(vars.at(0));
   hist = data->createHistogram( name.c_str(),*varX, RooFit::Binning(varX->getBinning()) );
      }
      else if( dim==2 ) {
   RooRealVar* varX = static_cast<RooRealVar*>(vars.at(0));
   RooRealVar* varY = static_cast<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 = static_cast<RooRealVar*>(vars.at(0));
   RooRealVar* varY = static_cast<RooRealVar*>(vars.at(1));
   RooRealVar* varZ = static_cast<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");
   if (dataset_list) {
      dataset_list->Delete();
      dataset_list.reset();
   }
   throw hf_exc();
      }
 
   if (dataset_list) {
      dataset_list->Delete();
      dataset_list.reset();
   }
 
      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!=nullptr ) {
   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
      // Loop over the subnodes and add
      for (auto *arg : node->components()) {
        std::string ClassName = arg->ClassName();
        if( ClassName == "RooProduct" ) {
            RooProduct* prod = static_cast<RooProduct*>(arg);
            allTerms.add( _GetAllProducts(prod) );
        }
        else {
            allTerms.add(*arg);
        }
      }
      return allTerms;
    }
 
 
 
 
    void HistFactoryNavigation::_GetNodes(RooAbsPdf* modelPdf, const RooArgSet* observables) {
 
      // Get the pdf from the ModelConfig
      //RooAbsPdf* modelPdf = mc->GetPdf();
      //RooArgSet* observables = mc->GetObservables();
 
      // 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:
   auto simPdf = static_cast<RooSimultaneous*>(modelPdf);
   auto channelCat = static_cast<RooCategory const*>(&simPdf->indexCat());
 
   // Iterate over the categories and get the
   // pdf and observables for each category
   for (const auto& nameIdx : *channelCat) {
     const std::string& ChannelName = nameIdx.first;
     fChannelNameVec.push_back( ChannelName );
     RooAbsPdf* pdftmp = simPdf->getPdf(ChannelName.c_str()) ;
     RooArgSet* obstmp = std::unique_ptr<RooArgSet>{pdftmp->getObservables(*observables)}.release();
     fChannelPdfMap[ChannelName] = pdftmp;
     fChannelObservMap[ChannelName] =  obstmp;
   }
 
      } else {
   RooArgSet* obstmp = std::unique_ptr<RooArgSet>{modelPdf->getObservables(*observables)}.release();
   // 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];
 
   // 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
   std::unique_ptr<RooArgSet> comps{pdf->getComponents()};
    for (auto *arg : *comps) {
      std::string ClassName = arg->ClassName();
      if( ClassName == "RooRealSumPdf" ) {
         fChannelSumNodeMap[ChannelName] = static_cast <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
  for (auto *func : static_range_cast<RooAbsReal *>(sumPdf->funcList())) {
    // Do a bit of work to get the name of each sample
    std::string SampleName = func->GetName();
    if( SampleName.find("L_x_") != std::string::npos ) {
      size_t index = SampleName.find("L_x_");
      SampleName.replace( index, 4, "" );
    }
    if( SampleName.find(ChannelName) != std::string::npos ) {
      size_t index = SampleName.find(ChannelName);
      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=nullptr;
 
      // Check if it is a "component",
      // ie a sub node:
      std::unique_ptr<RooArgSet> comps{parent->getComponents()};
      for (auto arg : *comps) {
         std::string ArgName = arg->GetName();
         if (ArgName == name) {
            term = arg;
            break;
         }
      }
 
      if( term != nullptr ) return term;
 
      // If that failed,
      // Check if it's a Parameter
      // (ie a RooRealVar)
      RooArgSet args;
      std::unique_ptr<RooArgSet> parameters{parent->getParameters(&args)};
      for (auto *param : *parameters) {
        std::string ParamName = param->GetName();
        if( ParamName == name ) {
            term = param;
            break;
        }
      }
 
      /* Not sure if we want to be silent
    But since we're returning a pointer which can be nullptr,
    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==nullptr ) {
    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==nullptr ) {
   std::cout << "Error: Couldn't Find parameter: " << parameter << " in model."
        << std::endl;
   return nullptr;
      }
 
      // 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==nullptr ) {
   std::cout << "Error: Couldn't Find constraint term for parameter: " << parameter
        << " (Looked for '" << ConstraintTermName << "')" << std::endl;
   return nullptr;
      }
 
      return term;
 
    }
 
 
    double HistFactoryNavigation::GetConstraintUncertainty(const std::string& parameter) {
 
      RooAbsReal* constraintTerm = GetConstraintTerm(parameter);
      if( constraintTerm==nullptr ) {
   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->ClassName();
 
      // Find its value
      double sigma = 0.0;
 
      if( ConstraintType.empty() ) {
   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==nullptr ) {
     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==nullptr ) {
     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 / std::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==nullptr ) {
        std::cout << "Error: Cannot replace node: " << ToReplace
            << " because this node wasn't found in: " << fModel->GetName()
            << std::endl;
        throw hf_exc();
      }
 
 
      const std::string attrib = "ORIGNAME:" + ToReplace;
      const bool oldAttrib = ReplaceWith->getAttribute(attrib.c_str());
      ReplaceWith->setAttribute(attrib.c_str());
      RooArgSet newServerSet{*ReplaceWith};
 
      // 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:
        client->redirectServers(newServerSet);
        std::cout << "Replaced: " << ToReplace << " with: " << ReplaceWith->GetName()
                << " in node: " << client->GetName() << std::endl;
 
      }
 
      // reset temporary attribute for server redirection
      ReplaceWith->setAttribute(attrib.c_str(), oldAttrib);
 
      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();
      std::unique_ptr<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
      {
        for (auto *component : static_range_cast<RooAbsReal*>(components)) {
          std::string NodeName = component->GetName();
          label_print_width = std::max(label_print_width, static_cast<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;
 
 
      for (auto *component : static_range_cast<RooAbsReal*>(components)) {
        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);
        std::unique_ptr<TH1> hist;
        hist.reset(MakeHistFromRooFunction( component, observable_list, NodeName+"_tmp"));
        RooMsgService::instance().setGlobalKillBelow(levelBefore);
 
        // Print the hist
        std::cout << std::setw(label_print_width) << NodeName;
 
        // Print the Histogram
        PrintMultiDimHist(hist.get(), bin_print_width);
      }
      /////
      std::string line_break;
      int high_bin = _maxBinToPrint==-1 ? num_bins : std::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.get(), bin_print_width);
    }
 
 
    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.size();
 
      TH1* hist=nullptr;
 
      if( dim==1 ) {
   RooRealVar* varX = static_cast<RooRealVar*>(vars.at(0));
   hist = func->createHistogram( name.c_str(),*varX, RooFit::Binning(varX->getBinning()), RooFit::Scaling(false) );
      }
      else if( dim==2 ) {
   RooRealVar* varX = static_cast<RooRealVar*>(vars.at(0));
   RooRealVar* varY = static_cast<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 = static_cast<RooRealVar*>(vars.at(0));
   RooRealVar* varY = static_cast<RooRealVar*>(vars.at(1));
   RooRealVar* varZ = static_cast<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, params);
 
      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
      for (auto *param : static_range_cast<RooRealVar *>(params)) {
 
          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 nullptr;
 
      RooRealVar* var_obj = dynamic_cast<RooRealVar*>(arg);
      return var_obj;
 
    }
 
  } // namespace HistFactory
} // namespace RooStats