rf505_asciicfg.C

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/// \file
/// \ingroup tutorial_roofit
/// \notebook -nodraw
/// Organisation and simultaneous fits: reading and writing ASCII configuration files
///
/// \macro_code
/// \macro_output
///
/// \date July 2008
/// \author Wouter Verkerke
 
#include "RooRealVar.h"
#include "RooDataSet.h"
#include "RooGaussian.h"
#include "RooPolynomial.h"
#include "RooAddPdf.h"
#include "TCanvas.h"
#include "TAxis.h"
#include "RooPlot.h"
using namespace RooFit;
 
void rf505_asciicfg()
{
   // C r e a t e  p d f
   // ------------------
 
   // Construct gauss(x,m,s)
   RooRealVar x("x", "x", -10, 10);
   RooRealVar m("m", "m", 0, -10, 10);
   RooRealVar s("s", "s", 1, -10, 10);
   RooGaussian gauss("g", "g", x, m, s);
 
   // Construct poly(x,p0)
   RooRealVar p0("p0", "p0", 0.01, 0., 1.);
   RooPolynomial poly("p", "p", x, p0);
 
   // Construct model = f*gauss(x) + (1-f)*poly(x)
   RooRealVar f("f", "f", 0.5, 0., 1.);
   RooAddPdf model("model", "model", RooArgSet(gauss, poly), f);
 
   // F i t   m o d e l   t o   t o y   d a t a
   // -----------------------------------------
 
   RooDataSet *d = model.generate(x, 1000);
   model.fitTo(*d, PrintLevel(-1));
 
   // W r i t e   p a r a m e t e r s   t o   a s c i i   f i l e
   // -----------------------------------------------------------
 
   // Obtain set of parameters
   std::unique_ptr<RooArgSet> params{model.getParameters(x)};
 
   // Write parameters to file
   params->writeToFile("rf505_asciicfg_example.txt");
 
   TString dir1 = gROOT->GetTutorialDir() ;
   dir1.Append("/roofit/rf505_asciicfg.txt") ;
   TString dir2 = "rf505_asciicfg_example.txt";
 
   // R e a d    p a r a m e t e r s   f r o m    a s c i i   f i l e
   // ----------------------------------------------------------------
 
   // Read parameters from file
   params->readFromFile(dir2);
   params->Print("v");
 
   // Read parameters from section 'Section2' of file
   params->readFromFile(dir1, 0, "Section2");
   params->Print("v");
 
   // Read parameters from section 'Section3' of file. Mark all
   // variables that were processed with the "READ" attribute
   params->readFromFile(dir1, "READ", "Section3");
 
   // Print the list of parameters that were not read from Section3
   cout << "The following parameters of the were _not_ read from Section3: "
        << (*params->selectByAttrib("READ", false)) << endl;
 
   // Read parameters from section 'Section4' of file, which contains
   // 'include file' statement of rf505_asciicfg_example.txt
   // so that we effective read the same
 
   params->readFromFile(dir1, 0, "Section4");
   params->Print("v");
}