rs601_HLFactoryexample.C

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/// \file
/// \ingroup tutorial_roostats
/// \notebook -js
/// 'High Level Factory Example' RooStats tutorial macro #601
///
/// This tutorial shows an example of creating a simple
/// model using the High Level model Factory.
///
/// \macro_image
/// \macro_output
/// \macro_code
///
/// \author Danilo Piparo

#include <fstream>
#include "TString.h"
#include "TROOT.h"
#include "RooGlobalFunc.h"
#include "RooWorkspace.h"
#include "RooRealVar.h"
#include "RooAbsPdf.h"
#include "RooDataSet.h"
#include "RooPlot.h"
#include "RooStats/HLFactory.h"


// use this order for safety on library loading
using namespace RooFit;
using namespace RooStats;
using namespace std;

void rs601_HLFactoryexample() {

   // --- Build the datacard and dump to file---

   TString card_name("HLFavtoryexample.rs");
   ofstream ofile(card_name);
   ofile << "// The simplest card\n\n"
      << "gauss = Gaussian(mes[5.20,5.30],mean[5.28,5.2,5.3],width[0.0027,0.001,1]);\n"
      << "argus = ArgusBG(mes,5.291,argpar[-20,-100,-1]);\n"
      << "sum = SUM(nsig[200,0,10000]*gauss,nbkg[800,0,10000]*argus);\n\n";

   ofile.close();

   HLFactory hlf("HLFavtoryexample",
                  card_name,
                  false);

   // --- Take elements out of the internal workspace ---

   RooWorkspace* w = hlf.GetWs();

   RooRealVar* mes = dynamic_cast<RooRealVar*>(w->arg("mes"));
   RooAbsPdf* sum = dynamic_cast<RooAbsPdf*>(w->pdf("sum"));
   RooAbsPdf* argus = dynamic_cast<RooAbsPdf*>(w->pdf("argus"));
//   RooRealVar* mean = dynamic_cast<RooRealVar*>(w->arg("mean"));
//   RooRealVar* argpar = dynamic_cast<RooRealVar*>(w->arg("argpar"));

   // --- Generate a toyMC sample from composite PDF ---
   RooDataSet *data = sum->generate(*mes,2000) ;

   // --- Perform extended ML fit of composite PDF to toy data ---
   sum->fitTo(*data) ;

   // --- Plot toy data and composite PDF overlaid ---
   RooPlot* mesframe = mes->frame() ;
   data->plotOn(mesframe) ;
   sum->plotOn(mesframe) ;
   sum->plotOn(mesframe,Components(*argus),LineStyle(kDashed)) ;

   gROOT->SetStyle("Plain");
   mesframe->Draw()  ;
}