doc/v606/rf105__funcbinding_8C.html

#ifndef __CINT__

#include "RooGlobalFunc.h"

#else

// Refer to a class implemented in libRooFit to force its loading

// via the autoloader.

class Roo2DKeysPdf;

#endif

#include "RooRealVar.h"

#include "RooDataSet.h"

#include "RooGaussian.h"

#include "TCanvas.h"

#include "TAxis.h"

#include "RooPlot.h"

#include "TMath.h"

#include "TF1.h"

#include "Math/DistFunc.h"

#ifndef __CINT__

#include "RooCFunction1Binding.h"

#include "RooCFunction3Binding.h"

#endif

#include "RooTFnBinding.h"


using namespace RooFit;


void rf105_funcbinding()

{


  // B i n d   T M a t h : : E r f   C   f u n c t i o n

  // ---------------------------------------------------


  // Bind one-dimensional TMath::Erf function as RooAbsReal function

  RooRealVar x("x","x",-3,3) ;

  RooAbsReal* erf = bindFunction("erf",TMath::Erf,x) ;


  // Print erf definition

  erf->Print() ;


  // Plot erf on frame

  RooPlot* frame1 = x.frame(Title("TMath::Erf bound as RooFit function")) ;

  erf->plotOn(frame1) ;


  // B i n d   R O O T : : M a t h : : b e t a _ p d f   C   f u n c t i o n

  // -----------------------------------------------------------------------


  // Bind pdf ROOT::Math::Beta with three variables as RooAbsPdf function

  RooRealVar x2("x2","x2",0,0.999) ;

  RooRealVar a("a","a",5,0,10) ;

  RooRealVar b("b","b",2,0,10) ;

  RooAbsPdf* beta = bindPdf("beta",ROOT::Math::beta_pdf,x2,a,b) ;


  // Perf beta definition

  beta->Print() ;


  // Generate some events and fit

  RooDataSet* data = beta->generate(x2,10000) ;

  beta->fitTo(*data) ;


  // Plot data and pdf on frame

  RooPlot* frame2 = x2.frame(Title("ROOT::Math::Beta bound as RooFit pdf")) ;

  data->plotOn(frame2) ;

  beta->plotOn(frame2) ;


  // B i n d   R O O T   T F 1   a s   R o o F i t   f u n c t i o n

  // ---------------------------------------------------------------


  // Create a ROOT TF1 function

  TF1 *fa1 = new TF1("fa1","sin(x)/x",0,10);


  // Create an observable

  RooRealVar x3("x3","x3",0.01,20) ;


  // Create binding of TF1 object to above observable

  RooAbsReal* rfa1 = bindFunction(fa1,x3) ;


  // Print rfa1 definition

  rfa1->Print() ;


  // Make plot frame in observable, plot TF1 binding function

  RooPlot* frame3 = x3.frame(Title("TF1 bound as RooFit function")) ;

  rfa1->plotOn(frame3) ;


  TCanvas* c = new TCanvas("rf105_funcbinding","rf105_funcbinding",1200,400) ;

  c->Divide(3) ;

  c->cd(1) ; gPad->SetLeftMargin(0.15) ; frame1->GetYaxis()->SetTitleOffset(1.6) ; frame1->Draw() ;

  c->cd(2) ; gPad->SetLeftMargin(0.15) ; frame2->GetYaxis()->SetTitleOffset(1.6) ; frame2->Draw() ;

  c->cd(3) ; gPad->SetLeftMargin(0.15) ; frame3->GetYaxis()->SetTitleOffset(1.6) ; frame3->Draw() ;


}