BCTemplateFitter.cxx

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#include <iostream>

#include <TROOT.h>
#include <TH2D.h>
#include <THStack.h>
#include <TCanvas.h>
#include <TLegend.h>
#include <TMath.h>
#include <TRandom3.h>
#include <TGraphAsymmErrors.h>
#include <TPostScript.h>
#include <TPad.h>
#include <TLine.h>
#include <TDirectory.h>

#include <BAT/BCMath.h>
#include <BAT/BCLog.h>
#include <BAT/BCH1D.h>

#include "BCTemplateFitter.h"

// ---------------------------------------------------------
BCTemplateFitter::BCTemplateFitter()
   : BCModel()
   , fFlagFixNorm(false)
   , fFlagPhysicalLimits(true)
   , fUncertaintyHistogramExp(0)
   , fUncertaintyHistogramObsPosterior(0)
   , fNorm(-1)
   , fNBins(-1)
   , fXmin(1.)
   , fXmax(0.)
   , fPriorNBins(1000)
{
}

// ---------------------------------------------------------
BCTemplateFitter::BCTemplateFitter(const char * name)
   : BCModel(name)
   , fFlagFixNorm(false)
   , fFlagPhysicalLimits(true)
   , fUncertaintyHistogramExp(0)
   , fUncertaintyHistogramObsPosterior(0)
   , fNorm(-1)
   , fNBins(-1)
   , fXmin(1.)
   , fXmax(0.)
   , fPriorNBins(1000)
{
}

// ---------------------------------------------------------
BCTemplateFitter::~BCTemplateFitter()
{
   if (fUncertaintyHistogramExp)
      delete fUncertaintyHistogramExp;

   if (fUncertaintyHistogramObsPosterior)
      delete fUncertaintyHistogramObsPosterior;
}

// ---------------------------------------------------------
double BCTemplateFitter::LogLikelihood(std::vector <double> parameters)
{
   double logprob = 0.;

   // get number pf templates
   int ntemplates = GetNTemplates();

   // get number of sources of systematic uncertainties
   int nsyst = GetNSystErrors();

   // loop over bins
   for (int ibin = 1; ibin <= fNBins; ++ibin) {
      double nexp = 0;
      double ndata = fHistData.GetBinContent(ibin);

      // loop over all templates
      for (int itemp = 0; itemp < ntemplates; ++itemp) {
         int templateindex = fTemplateParIndexContainer.at(itemp);
         int effindex = fEffParIndexContainer.at(itemp);

         // get efficiency for the bin
         double efficiency = fEffHistogramContainer.at(itemp).GetBinContent(ibin);

         // modify efficiency by uncertainty
         double efferr = fEffErrHistogramContainer.at(itemp).GetBinContent(ibin);

         // check efficiency error
         if (efferr > 0)
            efficiency += parameters.at(effindex) * efferr;

         // loop over sources of systematic uncertainties
         for (int isyst = 0; isyst < nsyst; ++isyst) {
            // get parameter index
            int systindex = fSystErrorParIndexContainer.at(isyst);

            // add efficiency
            double deff = fSystErrorHistogramContainer.at(isyst).at(itemp).GetBinContent(ibin);

            if (deff > 0)
               efficiency += deff * parameters.at(systindex);
         }

         // make sure efficiency is between 0 and 1
         if (efficiency < 0.)
            efficiency = 0.;
         if (efficiency > 1.)
            efficiency = 1.;

         // calculate expectation nvalue
         nexp += parameters.at(templateindex)
               * efficiency
               * fTemplateHistogramContainer.at(itemp).GetBinContent(ibin);
      }

      // check that expectation is larger or equal to zero
      if (nexp < 0) {
         BCLog::OutWarning("BCTemplateFitter::LogLikelihood : Expectation value smaller than 0. Force it to be 0.");
         nexp = 0;
      }

      // add Poisson term
      logprob += BCMath::LogPoisson(ndata, nexp);
   }

   // return log likelihood
   return logprob;
}

// ---------------------------------------------------------
double BCTemplateFitter::LogAPrioriProbability(std::vector <double> parameters)
{
   double logprob = 0.;

   // get number of templates
   int ntemplates = GetNTemplates();

   // loop over templates
   for (int i = 0; i < ntemplates; ++i) {

      // prior on process contributions
      double par = parameters.at(fTemplateParIndexContainer.at(i));
      int bin = fPriorContainer.at(i).FindBin(par);
      logprob += log( fPriorContainer.at(i).GetBinContent(bin) );

      // prior on efficiences
      par = parameters.at(fEffParIndexContainer.at(i));
      logprob += BCMath::LogGaus(par, 0.0, 1.0);
   }

   // get number of sources of systematic uncertainties
   int nsyst = GetNSystErrors();

   // loop over sources of systematic uncertainties
   for (int i = 0; i < nsyst; ++i) {
      double par = parameters.at(fSystErrorParIndexContainer.at(i));
      if (fSystErrorTypeContainer.at(i) == "gauss")
         logprob += BCMath::LogGaus(par, 0.0, 1.0);
   }

   // constraints
   int nconstraints = int(fConstraintSumIndices.size());
   if (nconstraints > 0) {

      // loop over constraints
      for (int i = 0; i < nconstraints; ++i) {

         // initialize sum
         double sum = 0;

         // get number of summands
         int nsummands = int( (fConstraintSumIndices.at(i)).size() );

         // loop over summands and add to sum
         for (int j = 0; j < nsummands; ++j) {
            int index = fConstraintSumIndices.at(i).at(j);
            double par = parameters.at(fTemplateParIndexContainer.at(index));
            sum += par;
         }

         // add to prior
         logprob += BCMath::LogGaus(sum, fConstraintSumMean.at(i), fConstraintSumRMS.at(i));
      }
   }

   return logprob;
}

// ---------------------------------------------------------
int BCTemplateFitter::SetData(const TH1D& hist)
{
   // create histogram
   fNBins = hist.GetNbinsX();
   fXmin = (hist.GetXaxis())->GetXmin();
   fXmax = (hist.GetXaxis())->GetXmax();
   fHistData = TH1D("", "", fNBins, fXmin, fXmax);

   // copy histogram content
   for (int i = 1; i <= fNBins; ++i)
      fHistData.SetBinContent(i, hist.GetBinContent(i));

   // set histogram style
   fHistData.SetXTitle((hist.GetXaxis())->GetTitle());
   fHistData.SetYTitle((hist.GetYaxis())->GetTitle());
   fHistData.SetMarkerStyle(20);
   fHistData.SetMarkerSize(1.1);
   fHistData.SetStats(kFALSE);

   // calculate norm
   fNorm = hist.Integral();

   // no errors
   return 1;
}

// ---------------------------------------------------------
int BCTemplateFitter::AddTemplate(TH1D hist, const char * name, double Nmin, double Nmax)
{
   // check if histogram if filled
   if (hist.Integral() <= 0.) {
      BCLog::OutError("BCTemplateFitter::AddTemplate : Normalization is zero or less than that.");
      return 0;
   }

   // compare template properties with data
   if (CompareHistogramProperties(fHistData, hist) != 1) {
      BCLog::OutError("BCTemplateFitter::AddTemplate : Data and template histogram properties are incompatible.");
      return 0;
   }

   // check if prior makes sense
   if (fFlagPhysicalLimits && Nmin < 0)
      Nmin = 0;

   if (Nmin > Nmax) {
      BCLog::OutError("BCTemplateFitter::AddTemplate : Lower limit exceeds upper limit.");
      return 0;
   }

   // get number of templates
   int ntemplates = int(fTemplateHistogramContainer.size());

   // set histogram color and style
   hist.SetFillColor(2 + ntemplates);
   hist.SetFillStyle(1001);
   hist.SetStats(kFALSE);

   // scale histogram
   hist.Scale(1.0 / hist.Integral());

   // check if template is consistent with other templates
   if (ntemplates > 0)
      if (!CompareHistogramProperties(fTemplateHistogramContainer.at(0), hist)) {
         BCLog::OutError("BCTemplateFitter::AddTemplate : Properties of template histogram is not compatible with older template histograms.");
         return 0;
      }

   // histograms
   TH1D histprior = TH1D("", "", fPriorNBins, Nmin, Nmax);
   TH1D histsysterror = TH1D("", "", fNBins, fXmin, fXmax);

   // set style
   histprior.SetXTitle(name);

   // fill histograms
   for (int i = 1; i <= fPriorNBins; ++i)
      histprior.SetBinContent(i, 1.);
   for (int i = 1; i <= fNBins; ++i)
      histsysterror.SetBinContent(i, 0.);

   // get parameter index
   int parindex = GetNParameters();
   int partemplateindex = GetNTemplates();

   // add a parameter for the expectation value
   AddParameter(Form("N_%i", partemplateindex), Nmin, Nmax);

   // get efficiency parameter index
   int effindex = GetNParameters();

   // add a parameter for the efficiency
   AddParameter(Form("eff_%i", partemplateindex), -5.0, 5.0);

   // add histogram, name and index to containers
   fTemplateHistogramContainer.push_back(hist);
   fPriorContainer.push_back(histprior);
   fTemplateNameContainer.push_back(name);
   fTemplateParIndexContainer.push_back(parindex);
   fEffParIndexContainer.push_back(effindex);

   // set efficiency histograms to one without uncertainty
   fEffHistogramContainer.push_back(TH1D());
   fEffErrHistogramContainer.push_back(TH1D());
   SetTemplateEfficiency(name, 1., 0.);

   // add systematic uncertainties
   for (int i = 0; i < GetNSystErrors(); ++i) {
      std::vector <TH1D> histvector = fSystErrorHistogramContainer.at(i);
      histvector.push_back(histsysterror);
   }

   // successfully added histogram to container
   return 1;
}

// ---------------------------------------------------------
int BCTemplateFitter::SetTemplatePrior(const char * name, TH1D prior)
{
   // get index
   int parindex = GetIndexTemplate(name);

   // check parameter index
   if (parindex < 0) {
      BCLog::OutError("BCTemplateFitter::SetTemplatePrior : Did not find parameter.");
      return 0;
   }

   // check prior
   if (prior.Integral() <= 0) {
      BCLog::OutError("BCTemplateFitter::SetTemplatePrior : Integral of prior is equal to zero or less than that.");
      return 0;
   }

   // normalize prior to unity
   prior.Scale(1.0/prior.Integral());

   // replace histogram
   fPriorContainer[parindex] = prior;

   // no error
   return 1;
}

// ---------------------------------------------------------
int BCTemplateFitter::SetTemplatePrior(const char * name, double mean, double sigma)
{
   // get index
   int parindex = GetParIndexTemplate(name);

   // check parameter index
   if (parindex < 0) {
      BCLog::OutError("BCTemplateFitter::SetTemplatePrior : Did not find parameter.");
      return 0;
   }

   // get parameter
   BCParameter * par = this->GetParameter(parindex);

   // create new histogram
   TH1D hist("", "", fPriorNBins, par->GetLowerLimit(), par->GetUpperLimit());

   // loop over bins and fill histogram
   for (int i = 1; i < fPriorNBins; ++i) {
      double x = hist.GetBinCenter(i);
      double fx = TMath::Gaus(x, mean, sigma);
      hist.SetBinContent(i, fx);
   }

   // set template prior
   int err = SetTemplatePrior(name, hist);

   // return error code
   return err;
}

// ---------------------------------------------------------
int BCTemplateFitter::AddSystError(const char * errorname, const char * errtype)
{
   // define parameter range
   double dx = 1.0;

   // check error type
   if (std::string(errtype) == std::string("gauss"))
      dx = 5.0;
   else if (std::string(errtype) == std::string("flat"))
      dx = 1.0;
   else {
      BCLog::OutError("BCTemplateFitter::AddSystError : Unknown error type.");
      return 0;
   }

   // add a parameter for the expectation value
   AddParameter(Form("systerr_%i", GetNSystErrors()), -dx, dx);

   // add name and index to containers
   fSystErrorNameContainer.push_back(errorname);
   fSystErrorParIndexContainer.push_back(GetNParameters()-1);

   // create histogram
   TH1D hist = TH1D("", "", fNBins, fXmin, fXmax);

   // fill histograms
   for (int i = 1; i <= fNBins; ++i)
      hist.SetBinContent(i, 0.);

   // get number of templates
   int n = GetNTemplates();

   // define vector of histograms
   std::vector<TH1D> histvector;

   // add histograms
   for (int i = 0; i < n; ++i)
      histvector.push_back(hist);

   // add histogram vector
   fSystErrorHistogramContainer.push_back(histvector);

   // add error type to container
   fSystErrorTypeContainer.push_back(std::string(errtype));

   // no error
   return 1;
}

// ---------------------------------------------------------
int BCTemplateFitter::SetTemplateSystError(const char * errorname, const char * templatename, TH1D parerror)
{
   // get error index
   int errindex = GetIndexSystError(errorname);

   // check parameter index
   if (errindex < 0) {
      BCLog::OutError("BCTemplateFitter::SetTemplateSystError : Did not find parameter.");
      return 0;
   }

   // get template index
   int tempindex = GetIndexTemplate(templatename);

   // check index
   if (tempindex < 0) {
      BCLog::OutError("BCTemplateFitter::SetTemplateSystError : Could not find template.");
      return 0;
   }

   // set style
   parerror.SetStats(kFALSE);

   // set histogram
   (fSystErrorHistogramContainer.at(errindex))[tempindex] = parerror;

   // no error
   return 1;
}

// ---------------------------------------------------------
int BCTemplateFitter::Initialize()
{
   // check data integral
   if (fHistData.Integral() <= 0) {
      BCLog::OutError("BCTemplateFitter::Initialize : Normalization of data histogram is zero or less than that.");
      return 0;
   }

   // create histograms for uncertainty determination
   double maximum = 1.5 * fHistData.GetMaximum();

   fUncertaintyHistogramExp = new TH2D(
         TString::Format("UncertaintyExp_%i", BCLog::GetHIndex()), "",
         fHistData.GetNbinsX(), fHistData.GetXaxis()->GetXmin(), fHistData.GetXaxis()->GetXmax(),
         100, 0., maximum);

   fUncertaintyHistogramObsPosterior = new TH2D(
         TString::Format("UncertaintyObsPosterior_%i", BCLog::GetHIndex()), "",
         fHistData.GetNbinsX(), fHistData.GetXaxis()->GetXmin(), fHistData.GetXaxis()->GetXmax(),
         int(maximum) + 1, -0.5, double(int(maximum))+0.5);

   // create histogram containing the normalization
   double xmin = 0;
   double xmax = 0;
   int ntemplates = int(fTemplateParIndexContainer.size());

   // calculate the limits on the norm from the sum of all parameter
   // limits
   for (int i = 0; i < ntemplates; ++i) {
      // get parameter index
      int parindex = fTemplateParIndexContainer.at(i);
      int effindex = fEffParIndexContainer.at(i);

      // get parameter
      BCParameter * par = this->GetParameter(parindex);
      BCParameter * eff = this->GetParameter(effindex);

      // increate limits
      xmin += par->GetLowerLimit() * eff->GetLowerLimit();
      xmax += par->GetUpperLimit() * eff->GetUpperLimit();
   }

   // create new histogram for norm
   fHistNorm = TH1D("", ";N_{norm};dN/dN_{norm}", 100, xmin, xmax);

   // no error
   return 1;
}

// ---------------------------------------------------------
int BCTemplateFitter::CalculateRatio(int index, std::vector<int> indices, double rmin, double rmax)
{
   // get number of templates
   int ntemplates = int( fTemplateHistogramContainer.size() );

   // check index
   if (index < 0 || index >= ntemplates) {
      return 0;
   }

   // check indices
   for (int i = 0; i < int(indices.size()); ++i) {
      if (indices.at(i) < 0 || indices.at(i) >= ntemplates) {
         return 0;
      }
   }

   // create temporary vector
   std::vector<int> tempvec;
   tempvec.push_back(index);
   for (int i = 0; i < int(indices.size()); ++i)
      tempvec.push_back(indices.at(i));

   // add ratio
   fIndicesRatios1D.push_back(tempvec);

   // get number of ratios
   int nratios = int(fHistRatios1D.size());

   // create histogram
   double fmin = rmin;
   double fmax = rmax;
   if (fFlagPhysicalLimits) {
      fmin = TMath::Max(rmin, 0.0);
      fmax = TMath::Min(1.0, rmax);
   }

   TH1D hist_ratio1d(TString::Format("ratio %i", nratios), ";r;p(r|data)", 100, fmin, fmax);
   fHistRatios1D.push_back(hist_ratio1d);

   // no error
   return 1;
}

// ---------------------------------------------------------
int BCTemplateFitter::CompareHistogramProperties(TH1D hist1, TH1D hist2)
{
   // compare number of bins
   if (hist1.GetNbinsX() != hist2.GetNbinsX())
      return 0;

   // compare minimum x-values
   if (hist1.GetXaxis()->GetXmin() != hist2.GetXaxis()->GetXmin())
      return 0;

   // compare maximum x-values
   if (hist1.GetXaxis()->GetXmax() != hist2.GetXaxis()->GetXmax())
      return 0;

   // conclusion: they have the same properties
   return 1;
}

// ---------------------------------------------------------
void BCTemplateFitter::PrintStack(const char * filename, const char * options)
{
   int nbins = fHistData.GetNbinsX();
   int ntemplates = int( fTemplateHistogramContainer.size() );

   // check options
   bool flag_legend = false;
   bool flag_error0 = false; // symm. poisson error for data
   bool flag_error1 = false; // symm. poisson error for exp.
   bool flag_error2 = false; // asymm. poisson error of expectation value
   bool flag_error3 = false; // asymm. poisson error of expected no. of events
   bool flag_diff   = false; // plot difference between data and expectation below stack plot

   if (std::string(options).find("L") < std::string(options).size())
      flag_legend = true;

   if (std::string(options).find("E0") < std::string(options).size())
      flag_error0 = true;

   if (std::string(options).find("E1") < std::string(options).size())
      flag_error1 = true;

   if (std::string(options).find("E2") < std::string(options).size())
      flag_error2 = true;

   if (std::string(options).find("E3") < std::string(options).size())
      flag_error3 = true;

   if (std::string(options).find("D") < std::string(options).size())
      flag_diff = true;

   // create canvas
   TCanvas* c1 = new TCanvas("", "", 700, 700);
   c1->cd();
   TPad * pad1;
   TPad * pad2;

   double fraction_pads = 0.3;

   if(!flag_diff)
      fraction_pads=0.0;

   if (flag_diff) {
      pad1 = new TPad("pad1", "", 0.0, fraction_pads, 1.0, 1.0);
      pad1->SetTopMargin   (0.13/(1.0-fraction_pads));
      pad1->SetBottomMargin(0.0);
      pad1->SetLeftMargin  (0.15);
      pad1->SetRightMargin (0.13);
      pad1->SetFillColor(kWhite);
      pad2 = new TPad("pad2", "", 0.0, 0.0, 1.0, fraction_pads);
      pad2->SetTopMargin   (0.0);
      pad2->SetBottomMargin(0.15 / fraction_pads);
      pad2->SetLeftMargin  (0.15);
      pad2->SetRightMargin (0.13);
      pad2->SetFillColor(kWhite);
      pad1->Draw();
      pad2->Draw();
   }
   else {
      pad1 = new TPad("pad1", "",0.0, 0.0, 1.0, 1.0);
      pad1->SetFillColor(kWhite);
      pad2 = new TPad();
      pad1->Draw();
   }

   pad1->cd();

   // set style and draw data
   double ymin = 0.01;
   double ymax = 1.1 * (fHistData.GetMaximum() + sqrt(fHistData.GetMaximum()));
   fHistData.GetYaxis()->SetRangeUser(ymin, ymax);
   fHistData.GetXaxis()->SetNdivisions(505);
   if (flag_diff) {
      fHistData.GetXaxis()->SetLabelSize(fHistData.GetXaxis()->GetLabelSize()/(1.0-fraction_pads));
      fHistData.GetXaxis()->SetLabelOffset(fHistData.GetXaxis()->GetLabelOffset()*(1.0-fraction_pads));
      fHistData.GetXaxis()->SetTitleSize(fHistData.GetXaxis()->GetTitleSize()/(1.0-fraction_pads));
      fHistData.GetXaxis()->SetTitleOffset(fHistData.GetXaxis()->GetTitleOffset()*(1.0-fraction_pads));
      fHistData.GetYaxis()->SetLabelSize(fHistData.GetYaxis()->GetLabelSize()/(1.0-fraction_pads));
      fHistData.GetYaxis()->SetLabelOffset(fHistData.GetYaxis()->GetLabelOffset()/(fraction_pads));
      fHistData.GetYaxis()->SetTitleSize(fHistData.GetYaxis()->GetTitleSize()/(1.0-fraction_pads));
      fHistData.GetYaxis()->SetTitleOffset(fHistData.GetYaxis()->GetTitleOffset()*(1.0-fraction_pads));
   }
   fHistData.Draw("P");

   // create a histogram with the sum of all contributions
   TH1D * histsum = (TH1D*) fHistData.Clone("temp");

   // create stack
   THStack stack("histostack","");

   // create legends
   TLegend* legend1;
   TLegend* legend2;

   if (flag_diff)
      legend1 = new TLegend(0.15, (0.88-fraction_pads)/(1-fraction_pads), 0.50, 0.99);
   else
      legend1 = new TLegend(0.15, 0.88, 0.50, 0.99);
   legend1->SetBorderSize(0);
   legend1->SetFillColor(kWhite);
   legend1->AddEntry(&fHistData, "Data", "LEP");
   legend1->AddEntry(&fHistData, "Total expected uncertainty", "LE");

   double y = 0.99;
   if (ntemplates > 2 && ntemplates <7)
      y -= 0.11 / 4. * double(ntemplates - 2);
   legend2 = new TLegend(0.50,(y-fraction_pads)/(1-fraction_pads) , 0.85, 0.99);
   legend2->SetBorderSize(0);
   legend2->SetFillColor(kWhite);

   // scale histograms and add to stack and legend
   for (int itemp = 0; itemp < ntemplates; ++itemp) {
      int tempindex = fTemplateParIndexContainer.at(itemp);
      int effindex = fEffParIndexContainer.at(itemp);

      // scale histogram
      fTemplateHistogramContainer.at(itemp).Scale(
            GetBestFitParameter(tempindex)/ fTemplateHistogramContainer.at(itemp).Integral());

      // loop over bins and scale these
      for (int ibin = 1; ibin <= fNBins; ++ibin) {
         // get efficiency for the bin
         double efficiency = fEffHistogramContainer.at(itemp).GetBinContent(ibin);

         // modify efficiency by uncertainty
         double efferr = fEffErrHistogramContainer.at(itemp).GetBinContent(ibin);

         // check efficiency error
         if (efferr > 0)
            efficiency = TMath::Max(0., efficiency + GetBestFitParameter(effindex) * efferr);

         fTemplateHistogramContainer.at(itemp).SetBinContent(
               ibin,fTemplateHistogramContainer.at(itemp).GetBinContent(ibin) * efficiency);
      }

      // add histogram to stack
      stack.Add(&(fTemplateHistogramContainer.at(itemp)));
      if (itemp < 2)
         legend1->AddEntry(&(fTemplateHistogramContainer.at(itemp)), fTemplateNameContainer.at(itemp).data(), "F");
      else if (itemp < 6)
         legend2->AddEntry(&(fTemplateHistogramContainer.at(itemp)), fTemplateNameContainer.at(itemp).data(), "F");
   }

   // loop over all bins
   for (int ibin = 1; ibin <= nbins; ++ibin) {
      double bincontent = 0;

      // loop over all templates
      for (int itemp = 0; itemp < ntemplates; ++itemp)
         bincontent +=fTemplateHistogramContainer.at(itemp).GetBinContent(ibin);

      // set bin content
      histsum->SetBinContent(ibin, bincontent);
   }

   // define error graph
   TGraphAsymmErrors * graph_error_exp = new TGraphAsymmErrors(nbins);
   graph_error_exp->SetLineWidth(2);
   graph_error_exp->SetMarkerStyle(0);

   TGraphAsymmErrors * graph_error_obs = new TGraphAsymmErrors(nbins);
   graph_error_obs->SetMarkerStyle(0);

   // calculate uncertainty
   if (flag_error1)
      for (int i = 1; i <= nbins; ++i) {
         double nexp = histsum->GetBinContent(i);
         histsum->SetBinError(i, sqrt(nexp));
         histsum->SetMarkerStyle(0);
      }

   if (flag_error2)
      for (int i = 1; i <= nbins; ++i) {
         TH1D * proj = fUncertaintyHistogramExp->ProjectionY("_py", i, i);
         if (proj->Integral() > 0)
            proj->Scale(1.0 / proj->Integral());
         double quantiles[3];
         double sums[3] = {0.16, 0.5, 0.84};
         proj->GetQuantiles(3, quantiles, sums);
         graph_error_exp->SetPoint(i-1, histsum->GetBinCenter(i), quantiles[1]);
         graph_error_exp->SetPointError(i-1, 0.0, 0.0, quantiles[1] - quantiles[0], quantiles[2]-quantiles[1]);
         delete proj;
      }

   if (flag_error3)
      for (int i = 1; i <= nbins; ++i) {
         TH1D * proj = fUncertaintyHistogramObsPosterior->ProjectionY("_py", i, i);
         if (proj->Integral() > 0)
            proj->Scale(1.0 / proj->Integral());
         double quantiles[3];
         double sums[3] = {0.16, 0.5, 0.84};
         proj->GetQuantiles(3, quantiles, sums);
         graph_error_obs->SetPoint(i-1, histsum->GetBinCenter(i), quantiles[1]);
         graph_error_obs->SetPointError(i-1, 0.0, 0.0, quantiles[1] - TMath::Floor(quantiles[0]), TMath::Ceil(quantiles[2])-quantiles[1]);
         delete proj;
      }

   // create difference histogram
   TH1D * hist_diff = 0;

   TGraphAsymmErrors * graph_diff_exp = 0;

   if (flag_diff) {
      ymin = 0;
      ymax = 0;
      hist_diff = new TH1D("hist_diff", "", nbins, histsum->GetXaxis()->GetXmin(), histsum->GetXaxis()->GetXmax() );
      hist_diff->GetXaxis()->SetTitle(fHistData.GetXaxis()->GetTitle());
      hist_diff->GetYaxis()->SetTitle("#Delta N");
      hist_diff->GetXaxis()->SetNdivisions(505);
      hist_diff->GetXaxis()->SetLabelSize(hist_diff->GetXaxis()->GetLabelSize()/(fraction_pads));
      hist_diff->GetXaxis()->SetLabelOffset(hist_diff->GetXaxis()->GetLabelOffset()/fraction_pads*2.);
      hist_diff->GetXaxis()->SetTitleSize(hist_diff->GetXaxis()->GetTitleSize()/(fraction_pads));
      hist_diff->GetXaxis()->SetTitleOffset((hist_diff->GetXaxis()->GetTitleOffset()-(1.0-fraction_pads))/(fraction_pads));
      hist_diff->GetYaxis()->SetNdivisions(503);
      hist_diff->GetYaxis()->SetLabelSize(hist_diff->GetYaxis()->GetLabelSize()/(fraction_pads));
      hist_diff->GetYaxis()->SetLabelOffset(hist_diff->GetYaxis()->GetLabelOffset()/(fraction_pads));
      hist_diff->GetYaxis()->SetTitleSize(hist_diff->GetYaxis()->GetTitleSize()/(fraction_pads));
      hist_diff->GetYaxis()->SetTitleOffset(hist_diff->GetYaxis()->GetTitleOffset()*(fraction_pads));
      hist_diff->SetStats(kFALSE);

      graph_diff_exp = new TGraphAsymmErrors(nbins);
      graph_diff_exp->SetLineWidth(2);
      graph_diff_exp->SetMarkerStyle(0);
      graph_diff_exp->SetFillColor(kYellow);
      for (int i = 0; i < nbins; ++i) {
         hist_diff->SetBinContent(i+1, fHistData.GetBinContent(i+1)-histsum->GetBinContent(i+1));
         hist_diff->SetBinError(i+1, fHistData.GetBinError(i+1));
         graph_diff_exp->SetPoint(i, (graph_error_exp->GetX())[i], 0.0);
         graph_diff_exp->SetPointEXlow(i, 0.0);
         graph_diff_exp->SetPointEXhigh(i, 0.0);
         graph_diff_exp->SetPointEYlow(i, (graph_error_exp->GetEYlow())[i]);
         graph_diff_exp->SetPointEYhigh(i, (graph_error_exp->GetEYhigh())[i]);

         if (-(graph_error_exp->GetEYlow())[i] < ymin)
            ymin = -(graph_error_exp->GetEYlow())[i];
         if ((graph_error_exp->GetEYhigh())[i] > ymax)
            ymax = (graph_error_exp->GetEYhigh())[i];
      }
      if (ymax < (hist_diff->GetMaximum() + hist_diff->GetBinError(hist_diff->GetMaximumBin())))
         ymax = 1.1 * (hist_diff->GetMaximum() + hist_diff->GetBinError(hist_diff->GetMaximumBin()));
      if (ymin>(hist_diff->GetMinimum() - hist_diff->GetBinError(hist_diff->GetMaximumBin())))
         ymin = 1.1 * (hist_diff->GetMinimum() - hist_diff->GetBinError(hist_diff->GetMaximumBin()));
      (hist_diff->GetYaxis())->SetRangeUser(-1.1*TMath::Max(-ymin, ymax), 1.1*TMath::Max(-ymin, ymax));

   }

   // draw histograms
   stack.Draw("SAMEA");
   stack.GetHistogram() -> SetXTitle("");
   stack.GetHistogram() -> SetYTitle("");
   stack.GetHistogram() -> GetXaxis() -> SetLabelSize(0);
   stack.GetHistogram() -> GetYaxis() -> SetLabelSize(0);
   stack.Draw("SAME");
   fHistData.Draw("SAMEP");

   if (flag_error0)
      fHistData.Draw("SAMEPE");

   if (flag_error1)
      histsum->Draw("SAMEE");

   if (flag_error3)
      graph_error_obs->Draw("SAMEZ");

   if (flag_error2)
      graph_error_exp->Draw("SAME||");

   if (flag_legend) {
      legend1->Draw();
      if (ntemplates>2)
      legend2->Draw();
   }

   TLine * line = 0;
   if (flag_diff) {
      pad2->cd();
      hist_diff->Draw("P");
      graph_diff_exp->Draw("SAME4");
      line = new TLine((hist_diff->GetXaxis())->GetXmin(), 0.0, (hist_diff->GetXaxis())->GetXmax(), 0.0);
      line->SetLineWidth(2);
      line->SetLineColor(kBlack);
      line->Draw("SAME");
      hist_diff->Draw("SAMEP");
   }

   c1->Print(filename);

   // rescale
   for (int i = 0; i < ntemplates; ++i)
      fTemplateHistogramContainer.at(i).Scale(1.0 / fTemplateHistogramContainer.at(i).Integral());

   // delete temporary histograms
   delete pad1;
   delete pad2;
   delete c1;
   delete legend1;
   delete legend2;
   delete graph_error_exp;
   delete graph_error_obs;
   delete histsum;
   if (flag_diff) {
      delete hist_diff;
      delete graph_diff_exp;
      delete line;
   }
}

// ---------------------------------------------------------
double BCTemplateFitter::CalculateChi2()
{
   int nbins = fHistData.GetNbinsX();
   int ntemplates = int(fTemplateHistogramContainer.size());

   std::vector <double> parameters = GetBestFitParameters();

   double chi2 = 0;

   // loop over all bins
   for (int ibin = 1; ibin <= nbins; ++ibin) {
      double nexp = 0;
      double ndata = fHistData.GetBinContent(ibin);

      // loop over all templates
      for (int itemp = 0; itemp < ntemplates; ++itemp) {
         int tempindex = fTemplateParIndexContainer.at(itemp);
         int effindex = fEffParIndexContainer.at(itemp);

         // get efficiency for the bin
         double efficiency = fEffHistogramContainer.at(itemp).GetBinContent(ibin);

         // modify efficiency by uncertainty
         double efferr = fEffErrHistogramContainer.at(itemp).GetBinContent(ibin);

         // check efficiency error
         if (efferr > 0)
            efficiency = TMath::Max(0., efficiency + parameters.at(effindex) * efferr);

         // add expectation from bin
         nexp += parameters.at(tempindex) * efficiency * fTemplateHistogramContainer.at(itemp).GetBinContent(ibin);
      }

      // add to chi2
      chi2 += (nexp - ndata) * (nexp - ndata) / nexp;
   }

   // return chi2
   return chi2;
}

// ---------------------------------------------------------
double BCTemplateFitter::CalculateChi2Prob()
{
   double chi2 = CalculateChi2();
   int ndf = GetNDF();

   // return chi2 probability
   return TMath::Prob(chi2, ndf);
}

// ---------------------------------------------------------
double BCTemplateFitter::CalculateMaxLike()
{
   // return maximum likelihood
   return Eval( GetBestFitParameters() );
}

// ---------------------------------------------------------
double BCTemplateFitter::CalculateKSProb()
{
   // create a histogram with the sum of all contributions
   TH1 * histsum = (TH1D*)(fTemplateHistogramContainer.at(0)).Clone("temp");

   int nbins = fHistData.GetNbinsX();
   int ntemplates = int(fTemplateHistogramContainer.size());

   std::vector <double> parameters = GetBestFitParameters();

   // loop over all bins
   for (int ibin = 1; ibin <= nbins; ++ibin) {
      double bincontent = 0;

      // loop over all templates
      for (int itemp = 0; itemp < ntemplates; ++itemp) {
         int tempindex = fTemplateParIndexContainer.at(itemp);
         int effindex = fEffParIndexContainer.at(itemp);

         // get efficiency for the bin
         double efficiency = fEffHistogramContainer.at(itemp).GetBinContent(ibin);

         // modify efficiency by uncertainty
         double efferr = fEffErrHistogramContainer.at(itemp).GetBinContent(ibin);

         // check efficiency error
         if (efferr > 0)
            efficiency = TMath::Max(0., efficiency + parameters.at(effindex) * efferr);

         // add expectation from bin
         bincontent += parameters.at(tempindex) * efficiency * fTemplateHistogramContainer.at(itemp).GetBinContent(ibin);
      }

      // set bin content
      histsum->SetBinContent(ibin, bincontent);
   }

   // perform KS test
   double ksprob = histsum->KolmogorovTest(&fHistData);

   // delete histogram
   delete histsum;

   return ksprob;
}

// ---------------------------------------------------------
double BCTemplateFitter::CalculatePValue()
{
   // get best fit parameters
   std::vector<double> par = GetBestFitParameters();

   // check size of parameter vector
   if (par.size() != GetNParameters()) {
      BCLog::OutWarning("BCBCTemplateFitter::CalculatePValueFast : Number of parameters is inconsistent.");
      return -1;
   }

   // define temporary variables
   int nbins = fHistData.GetNbinsX();
   int ntemplates = int( fTemplateHistogramContainer.size() );

   std::vector <int> histogram;
   std::vector <double> expectation;
   histogram.assign(nbins, 0);
   expectation.assign(nbins, 0);

   double logp = 0;
   double logp_start = 0;
   int counter_pvalue = 0;

   // define starting distribution
   for (int ibin = 1; ibin <= nbins; ++ibin) {
      double nexp = 0;

      // loop over all templates
      for (int itemp = 0; itemp < ntemplates; ++itemp) {
         int tempindex = fTemplateParIndexContainer.at(itemp);
         int effindex = fEffParIndexContainer.at(itemp);

         // get efficiency for the bin
         double efficiency = fEffHistogramContainer.at(itemp).GetBinContent(ibin);

         // modify efficiency by uncertainty
         double efferr = fEffErrHistogramContainer.at(itemp).GetBinContent(ibin);

         // check efficiency error
         if (efferr > 0)
            efficiency = TMath::Max(0., efficiency + par.at(effindex) * efferr);

         // add expectation from bin
         nexp += par.at(tempindex) * efficiency * fTemplateHistogramContainer.at(itemp).GetBinContent(ibin);
      }

      histogram[ibin-1]   = int(nexp);
      expectation[ibin-1] = nexp;

      // calculate p;
      logp += BCMath::LogPoisson(double(int(nexp)), nexp);
      logp_start += BCMath::LogPoisson(fHistData.GetBinContent(ibin), nexp);
   }

   int niter = 100000;

   // loop over iterations
   for (int iiter = 0; iiter < niter; ++iiter) {
      // loop over bins
      for (int ibin = 0; ibin < nbins; ++ibin) {
         // random step up or down in statistics for this bin
         double ptest = fRandom->Rndm() - 0.5;

         // increase statistics by 1
         if (ptest > 0) {
            // calculate factor of probability
            double r = expectation.at(ibin) / double(histogram.at(ibin) + 1);

            // walk, or don't (this is the Metropolis part)
            if (fRandom->Rndm() < r) {
               histogram[ibin] = histogram.at(ibin) + 1;
               logp += log(r);
            }
         }

         // decrease statistics by 1
         else if (ptest <= 0 && histogram[ibin] > 0) {
            // calculate factor of probability
            double r = double(histogram.at(ibin)) / expectation.at(ibin);

            // walk, or don't (this is the Metropolis part)
            if (fRandom->Rndm() < r) {
               histogram[ibin] = histogram.at(ibin) - 1;
               logp += log(r);
            }
         }
      } // end of looping over bins

      // increase counter
      if (logp < logp_start)
         counter_pvalue++;

   } // end of looping over iterations

   // calculate p-value
   return double(counter_pvalue) / double(niter);
}

// ---------------------------------------------------------
void BCTemplateFitter::MCMCUserIterationInterface()
{
   int nbins      = fHistData.GetNbinsX();
   int ntemplates = int(fTemplateHistogramContainer.size());

   // loop over all bins
   for (int ibin = 1; ibin <= nbins; ++ibin) {
      double bincontent = 0;

      // loop over all templates
      for (int itemp = 0; itemp < ntemplates; ++itemp) {
         int tempindex = fTemplateParIndexContainer.at(itemp);
         int effindex = fEffParIndexContainer.at(itemp);

         // get efficiency for the bin
         double efficiency = fEffHistogramContainer.at(itemp).GetBinContent(ibin);

         // modify efficiency by uncertainty
         double efferr = fEffErrHistogramContainer.at(itemp).GetBinContent(ibin);

         // check efficiency error
         if (efferr > 0)
            efficiency = TMath::Max(0., efficiency + fMCMCx.at(effindex) * efferr);

         bincontent += fMCMCx.at(tempindex) * efficiency * fTemplateHistogramContainer.at(itemp).GetBinContent(ibin);
      }

      // set bin content
      fUncertaintyHistogramExp->Fill(fHistData.GetBinCenter(ibin), bincontent);

      // loop over bins in the other direction
      int nbinsy = fUncertaintyHistogramObsPosterior->GetNbinsY();
      for (int jbin = 1; jbin <= nbinsy; ++jbin) {
         int n = jbin - 1;
         if (fabs(n - bincontent) < 2*sqrt(bincontent))
            fUncertaintyHistogramObsPosterior->Fill(fHistData.GetBinCenter(ibin), n, TMath::Poisson(bincontent, n));
      }
   }

   // fill normalization
   fHistNorm.Fill(fNorm);

   // fill ratios
   int nratios = int( fIndicesRatios1D.size() );

   // loop over fractions to fill
   for (int i = 0; i < nratios; ++i) {
      int nsum = int( (fIndicesRatios1D.at(i)).size() ) - 1;
      double sum = 0;
      for (int j = 1; j <= nsum; ++j) {
         int indexsum = fIndicesRatios1D.at(i).at(j);
         sum += fMCMCx.at(fTemplateParIndexContainer.at(indexsum));
      }

      fHistRatios1D.at(i).Fill(fMCMCx.at(fTemplateParIndexContainer.at(fIndicesRatios1D.at(i).at(0)))/sum);
   }

}

// ---------------------------------------------------------
void BCTemplateFitter::PrintRatios(const char * filename, int options, double ovalue)
{
   int nratios = int(fHistRatios1D.size());

   TCanvas * c1 = new TCanvas("");

   TPostScript * ps = new TPostScript(filename, 112);
   ps->NewPage();

   c1->cd();
   BCH1D * h1temp = new BCH1D(&fHistNorm);
   h1temp->Draw();
   c1->Update();
   ps->NewPage();
   for (int i = 0; i < nratios; ++i) {
      c1->Update();
      ps->NewPage();
      c1->cd();
      BCH1D* h1temp = new BCH1D(&fHistRatios1D.at(i));
      h1temp->Draw(options, ovalue);
   }
   c1->Update();
   ps->Close();

   delete c1;
   delete ps;
}

// ---------------------------------------------------------
int BCTemplateFitter::SetTemplateEfficiency(const char * name, TH1D eff, TH1D efferr)
{
   // get index
   int index = GetIndexTemplate(name);

   // check index
   if (index < 0) {
      BCLog::OutError("BCTemplateFitter::SetTemplateEfficiency : Could not find template.");
      return 0;
   }

   // check efficiency histogram
   if (CompareHistogramProperties(fTemplateHistogramContainer.at(index), eff) != 1) {
      BCLog::OutError("BCTemplateFitter::SetTemplate efficiency : Template and efficiency histogram properties are incompatible.");
      return 0;
   }

   // set histogram style
   eff.SetXTitle((fHistData.GetXaxis())->GetTitle());
   eff.SetYTitle("Efficiency");

   efferr.SetXTitle((fHistData.GetXaxis())->GetTitle());
   efferr.SetYTitle("Efficiency uncertainty");

   // set efficiency histogram
   fEffHistogramContainer[index] = eff;
   fEffErrHistogramContainer[index] = efferr;

   // no error
   return 1;
}

// ---------------------------------------------------------
int BCTemplateFitter::SetTemplateEfficiency(const char * name, double effmean, double effsigma)
{
   // get index
   int index = GetIndexTemplate(name);

   // check index
   if (index < 0) {
      BCLog::OutError("BCTemplateFitter::SetTemplateEfficiency : Could not find template.");
      return 0;
   }

   // create histograms
   TH1D histeff = TH1D("", "", fNBins, fXmin, fXmax);
   TH1D histefferr = TH1D("", "", fNBins, fXmin, fXmax);

   // fill histograms
   for (int i = 1; i <= fNBins; ++i) {
      histeff.SetBinContent(i, effmean);
      histefferr.SetBinContent(i, effsigma);
   }

   // set histograms
   int err = SetTemplateEfficiency(name, histeff, histefferr);

   // return error code
   return err;
}

// ---------------------------------------------------------
int BCTemplateFitter::ConstrainSum(std::vector <int> indices, double mean, double rms)
{
   // add contraint to container(s)
   fConstraintSumIndices.push_back(indices);
   fConstraintSumMean.push_back(mean);
   fConstraintSumRMS.push_back(rms);

   // no error
   return 1;
}

// ---------------------------------------------------------
void BCTemplateFitter::PrintTemp()
{
   TCanvas * c1 = new TCanvas("");

   c1->cd();
   fUncertaintyHistogramExp->Draw("COL");
   c1->Print("uncertainty_exp.eps");

   c1->cd();
   fUncertaintyHistogramObsPosterior->Draw("COL");
   c1->Print("uncertainty_obs.eps");

   delete c1;
}

// ---------------------------------------------------------
int BCTemplateFitter::PrintTemplate(const char * name, const char * filename)
{
   // get number of sources of systematic uncertainty
   int nsyst = GetNSystErrors();

   // get index
   int index = GetIndexTemplate(name);

   // check index
   if (index < 0) {
      BCLog::OutError("BCTemplateFitter::PrintTemplate : Could not find template.");
      return 0;
   }

   // remember old directory
   TDirectory* dir = gDirectory;

   // create postscript
   TPostScript * ps = new TPostScript(filename);

   // create new canvas
   TCanvas * c1 = new TCanvas("", "", 700, 700);

   c1->Update();
   ps->NewPage();
   c1->cd();

   // create legend
   TLegend l1(0.18, 0.75, 0.85, 0.85);
   l1.SetBorderSize(0);
   l1.SetFillColor(kWhite);

   // draw histogram and uncertainties
   TH1D hist_template = fTemplateHistogramContainer.at(index);
   hist_template.SetFillColor(kWhite);
   hist_template.SetFillStyle(0);
   hist_template.SetMarkerSize(0);
   hist_template.SetLineWidth(0);
   l1.AddEntry(&hist_template, name, "L");
   TH1D hist_totalerr = CombineUncertainties(name);
   TH1D hist_template_totalerr = CreateErrorHist(hist_template, hist_totalerr);
   hist_template_totalerr.SetFillColor(kYellow);
   hist_template_totalerr.SetFillStyle(1001);
   hist_template_totalerr.SetMarkerSize(0);
   l1.AddEntry(&hist_template_totalerr, "Systematic uncertainties", "F");
   TH1D hist_efferr = fEffErrHistogramContainer.at(index);
   TH1D hist_template_efferr = CreateErrorHist(hist_template, hist_efferr);
   hist_template_totalerr.SetFillColor(kRed);
   hist_template_totalerr.SetFillStyle(1001);
   hist_template_efferr.SetMarkerSize(0);
   l1.AddEntry(&hist_template_efferr, "Efficiency uncertainties", "F");
   int binmax = hist_template.GetMaximumBin();
   double ymax = hist_template.GetBinContent(binmax) + 2.0 * hist_template_totalerr.GetBinError(binmax);
   hist_template_totalerr.GetYaxis()->SetRangeUser(0.0, 1.25 * ymax);
   hist_template_totalerr.Draw("E2");
   hist_template_efferr.Draw("SAMEE2");
   hist_template.Draw("SAME");

   // draw legend
   l1.Draw();

   // update ps
   c1->Update();
   ps->NewPage();
   c1->cd();

   // create legend
   TLegend l2(0.18, 0.75, 0.85, 0.85);
   l2.SetBorderSize(0);
   l2.SetFillColor(kWhite);

   // print uncertainties
   c1->cd(2);
   hist_efferr = fEffErrHistogramContainer.at(index);
   double ymin = hist_efferr.GetMinimum();
   ymax = hist_efferr.GetMaximum();
   l2.AddEntry(&hist_efferr, "Efficiency", "L");
   hist_efferr.SetStats(kFALSE);
   hist_efferr.Draw();

   // loop over all uncertainties
   for (int i = 0; i < nsyst; ++i) {
      TH1D * hist = new TH1D(fSystErrorHistogramContainer.at(i).at(index));
      hist->SetLineColor(2 + i);
      if (hist->GetMaximum()>ymax)
         ymax = hist->GetMaximum();
      if (hist->GetMinimum()<ymin)
         ymin = hist->GetMinimum();
      l2.AddEntry(hist, fSystErrorNameContainer.at(i).c_str(), "L");
      hist->Draw("SAME");
   }
   if (ymin < 0)
      ymin = 1.25*ymin;
   else
      ymin = 0.8*ymin;

   if (ymax > 0)
      ymax = 1.25*ymax;
   else
      ymax = 0.8*ymax;

   hist_efferr.GetYaxis()->SetRangeUser(ymin, ymax);

   // draw legend
   l2.Draw();

   // close ps
   c1->Update();
   ps->Close();

   // change to old directory
   dir->cd();

   // free memory
   delete c1;
   delete ps;

   // no error
   return 1;
}

// ---------------------------------------------------------
TH1D BCTemplateFitter::CreateErrorHist(TH1D hist, TH1D histerr)
{
   // check histogram properties
   if (CompareHistogramProperties(fHistData, hist) != 1) {
      BCLog::OutError("BCTemplateFitter::CreateErrorHist : Histograms are incompatible.");
      return hist;
   }

   // copy histogram
   TH1D h = hist;

   // set style
   h.SetStats(kFALSE);
   h.SetFillColor(kYellow);
   h.SetFillStyle(1001);

   // get number of bins
   int nbins = hist.GetNbinsX();

   // loop over bins
   for (int i = 1; i <= nbins; ++i)
      h.SetBinError(i, histerr.GetBinContent(i) * hist.GetBinContent(i));

   // return histogram
   return h;
}

// ---------------------------------------------------------
TH1D BCTemplateFitter::CombineUncertainties(const char * name)
{
   // get number of sources of systematic uncertainty
   int nsyst = GetNSystErrors();

   // get template index
   int tempindex = GetIndexTemplate(name);

   // create new histogram
   TH1D hist = TH1D("", "", fNBins, fXmin, fXmax);

   // fill histogram
   for (int ibin = 1; ibin <= fNBins; ++ibin) {

      // define total uncertainty
      double err = 0;

      // add efficiency uncertainty squared
      double erreff = fEffErrHistogramContainer.at(tempindex).GetBinContent(ibin);
      err += erreff * erreff;

      // add systematic uncertainty squared
      for (int isyst = 0; isyst < nsyst; ++isyst) {
         double errsyst = fSystErrorHistogramContainer.at(isyst).at(tempindex).GetBinContent(ibin);
         err += errsyst*errsyst;
      }

      // take square root
      err = sqrt(err);

      // set bin content
      hist.SetBinContent(ibin, err);
   }

   // return histogram
   return hist;
}

// ---------------------------------------------------------
int BCTemplateFitter::GetIndexTemplate(const char * name)
{
   int index = -1;
   int n = GetNTemplates();

   for (int i = 0; i < n; i++)
      if (name == fTemplateNameContainer.at(i))
         index = i;

   if (index < 0) {
      BCLog::OutWarning("BCTemplateFitter::GetIndexTemplate : Template does not exist.");
      return 0;
   }

   // return index
   return index;
}

// ---------------------------------------------------------
int BCTemplateFitter::GetIndexSystError(const char * name)
{
   int index = -1;
   int n = GetNSystErrors();

   for (int i = 0; i < n; i++)
      if (name == fSystErrorNameContainer.at(i))
         index = i;

   if (index < 0) {
      BCLog::OutWarning("BCTemplateFitter::GetIndexSystError : Template does not exist.");
      return 0;
   }

   // return index
   return index;
}

// ---------------------------------------------------------
int BCTemplateFitter::GetParIndexTemplate(const char * name)
{
   int index = -1;
   int n = GetNTemplates();

   for (int i = 0; i < n; i++)
      if (name == fTemplateNameContainer.at(i))
         index = fTemplateParIndexContainer.at(i);

   if (index < 0) {
      BCLog::OutWarning("BCTemplateFitter::GetParIndexTemplate : Template does not exist.");
      return 0;
   }

   // return index
   return index;
}

// ---------------------------------------------------------
int BCTemplateFitter::GetParIndexTemplate(int index)
{
   // get number of templates
   int n = GetNTemplates();

   if (index < 0 || index > n) {
      BCLog::OutError("BCTemplateFitter::GetParIndexTemplate : Index out of range.");
      return -1;
   }

   // return index
   return fTemplateParIndexContainer.at(index);
}

// ---------------------------------------------------------
int BCTemplateFitter::GetParIndexEff(const char * name)
{
   int index = -1;
   int n = GetNTemplates();

   for (int i = 0; i < n; i++)
      if (name == fTemplateNameContainer.at(i))
         index = fTemplateParIndexContainer.at(i);

   if (index < 0) {
      BCLog::OutWarning("BCTemplateFitter::GetParIndexEff : Template does not exist.");
      return 0;
   }

   // return index
   return index;
}

// ---------------------------------------------------------
int BCTemplateFitter::GetParIndexSystError(const char * name)
{
   int index = -1;
   int n = GetNTemplates();

   for (int i = 0; i < n; i++)
      if (name == fSystErrorNameContainer.at(i))
         index = fSystErrorParIndexContainer.at(i);

   if (index < 0) {
      BCLog::OutWarning("BCTemplateFitter::GetParIndexStatError : Systematic error does not exist.");
      return 0;
   }

   // return index
   return index;
}

// ---------------------------------------------------------
int  BCTemplateFitter::PerformFit()
{
   // initialize
   if (!Initialize()) {
      BCLog::OutError("BCTemplateFitter::PerformFit : Could not initialize template fitter.");
      return 0;
   }

   // run Markov Chains
   MarginalizeAll();

   // find global mode
   FindMode();

   // no error
   return 1;
}
// ---------------------------------------------------------