doc/hackathon/rf105__funcbinding_8C.html

#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"

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


   // Print erf definition

   errorFunc->Print();


   // Plot erf on frame

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

   errorFunc->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

   std::unique_ptr<RooDataSet> data{beta->generate(x2, 10000)};

   beta->fitTo(*data, PrintLevel(-1));


   // 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();

}

DistFunc.h

b
#define b(i)
Definition RSha256.hxx:100

c
#define c(i)
Definition RSha256.hxx:101

a
#define a(i)
Definition RSha256.hxx:99

RooDataSet.h

RooGaussian.h

RooPlot.h

RooRealVar.h

RooTFnBinding.h

TAxis.h

TCanvas.h

TF1.h

TMath.h

gPad
#define gPad
Definition TVirtualPad.h:322

RooAbsArg::Print
void Print(Option_t *options=nullptr) const override
Print the object to the defaultPrintStream().
Definition RooAbsArg.h:238

RooAbsPdf
Abstract interface for all probability density functions.
Definition RooAbsPdf.h:32

RooAbsReal
Abstract base class for objects that represent a real value and implements functionality common to al...
Definition RooAbsReal.h:63

RooAbsReal::plotOn
virtual RooPlot * plotOn(RooPlot *frame, const RooCmdArg &arg1={}, const RooCmdArg &arg2={}, const RooCmdArg &arg3={}, const RooCmdArg &arg4={}, const RooCmdArg &arg5={}, const RooCmdArg &arg6={}, const RooCmdArg &arg7={}, const RooCmdArg &arg8={}, const RooCmdArg &arg9={}, const RooCmdArg &arg10={}) const
Plot (project) PDF on specified frame.
Definition RooAbsReal.cxx:1609

RooPlot
Plot frame and a container for graphics objects within that frame.
Definition RooPlot.h:43

RooPlot::frame
static RooPlot * frame(const RooAbsRealLValue &var, double xmin, double xmax, Int_t nBins)
Create a new frame for a given variable in x.
Definition RooPlot.cxx:185

RooPlot::GetYaxis
TAxis * GetYaxis() const
Definition RooPlot.cxx:1230

RooPlot::Draw
void Draw(Option_t *options=nullptr) override
Draw this plot and all of the elements it contains.
Definition RooPlot.cxx:597

RooRealVar
Variable that can be changed from the outside.
Definition RooRealVar.h:37

TAttAxis::SetTitleOffset
virtual void SetTitleOffset(Float_t offset=1)
Set distance between the axis and the axis title.
Definition TAttAxis.cxx:279

TCanvas
The Canvas class.
Definition TCanvas.h:23

TF1
Definition TF1.h:182

RooFit::Title
RooCmdArg Title(const char *name)
Definition RooGlobalFunc.cxx:532

RooFit::PrintLevel
RooCmdArg PrintLevel(Int_t code)
Definition RooGlobalFunc.cxx:659

ROOT::Math::beta_pdf
double beta_pdf(double x, double a, double b)
Probability density function of the beta distribution.
Definition PdfFuncMathCore.h:75

x
Double_t x[n]
Definition legend1.C:17

RooFit
The namespace RooFit contains mostly switches that change the behaviour of functions of PDFs (or othe...
Definition CodegenImpl.h:72

RooFit::bindPdf
RooAbsPdf * bindPdf(const char *name, CFUNCD1D func, RooAbsReal &x)
Definition RooCFunction1Binding.cxx:59

RooFit::bindFunction
RooAbsReal * bindFunction(const char *name, CFUNCD1D func, RooAbsReal &x)
Definition RooCFunction1Binding.cxx:51

TMath::Erf
Double_t Erf(Double_t x)
Computation of the error function erf(x).
Definition TMath.cxx:190

rf105_funcbinding
Definition rf105_funcbinding.py:1