doc/hackathon/rf704__amplitudefit_8C.html

#include "RooRealVar.h"

#include "RooDataSet.h"

#include "RooGaussian.h"

#include "RooFormulaVar.h"

#include "RooRealSumPdf.h"

#include "RooPolyVar.h"

#include "RooProduct.h"

#include "TH1.h"

#include "TCanvas.h"

#include "TAxis.h"

#include "RooPlot.h"

using namespace RooFit;


void rf704_amplitudefit()

{

   // S e t u p   2 D   a m p l i t u d e   f u n c t i o n s

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


   // Observables

   RooRealVar t("t", "time", -1., 15.);

   RooRealVar cosa("cosa", "cos(alpha)", -1., 1.);


   RooRealVar tau("tau", "#tau", 1.5);

   RooRealVar deltaGamma("deltaGamma", "deltaGamma", 0.3);

   RooFormulaVar coshG("coshGBasis", "exp(-@0/ @1)*cosh(@0*@2/2)", {t, tau, deltaGamma});

   RooFormulaVar sinhG("sinhGBasis", "exp(-@0/ @1)*sinh(@0*@2/2)", {t, tau, deltaGamma});


   // Construct polynomial amplitudes in cos(a)

   RooPolyVar poly1("poly1", "poly1", cosa, RooArgList{0.5, 0.2, 0.2}, 0);

   RooPolyVar poly2("poly2", "poly2", cosa, RooArgList{1.0, -0.2, 3.0}, 0);


   // Construct 2D amplitude as uncorrelated product of amp(t)*amp(cosa)

   RooProduct ampl1("ampl1", "amplitude 1", {poly1, coshG});

   RooProduct ampl2("ampl2", "amplitude 2", {poly2, sinhG});


   // C o n s t r u c t   a m p l i t u d e   s u m   p d f

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


   // Amplitude strengths

   RooRealVar f1("f1", "f1", 1, 0, 2);

   RooRealVar f2("f2", "f2", 0.5, 0, 2);


   // Construct pdf

   RooRealSumPdf pdf("pdf", "pdf", RooArgList(ampl1, ampl2), RooArgList(f1, f2));


   // Generate some toy data from pdf

   std::unique_ptr<RooDataSet> data{pdf.generate({t, cosa}, 10000)};


   // Fit pdf to toy data with only amplitude strength floating

   pdf.fitTo(*data, PrintLevel(-1));


   // P l o t   a m p l i t u d e   s u m   p d f

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


   // Make 2D plots of amplitudes

   TH1 *hh_cos = ampl1.createHistogram("hh_cos", t, Binning(50), YVar(cosa, Binning(50)));

   TH1 *hh_sin = ampl2.createHistogram("hh_sin", t, Binning(50), YVar(cosa, Binning(50)));

   hh_cos->SetLineColor(kBlue);

   hh_sin->SetLineColor(kRed);


   // Make projection on t, plot data, pdf and its components

   // Note component projections may be larger than sum because amplitudes can be negative

   RooPlot *frame1 = t.frame();

   data->plotOn(frame1);

   pdf.plotOn(frame1);

   pdf.plotOn(frame1, Components(ampl1), LineStyle(kDashed));

   pdf.plotOn(frame1, Components(ampl2), LineStyle(kDashed), LineColor(kRed));


   // Make projection on cosa, plot data, pdf and its components

   // Note that components projection may be larger than sum because amplitudes can be negative

   RooPlot *frame2 = cosa.frame();

   data->plotOn(frame2);

   pdf.plotOn(frame2);

   pdf.plotOn(frame2, Components(ampl1), LineStyle(kDashed));

   pdf.plotOn(frame2, Components(ampl2), LineStyle(kDashed), LineColor(kRed));


   TCanvas *c = new TCanvas("rf704_amplitudefit", "rf704_amplitudefit", 800, 800);

   c->Divide(2, 2);

   c->cd(1);

   gPad->SetLeftMargin(0.15);

   frame1->GetYaxis()->SetTitleOffset(1.4);

   frame1->Draw();

   c->cd(2);

   gPad->SetLeftMargin(0.15);

   frame2->GetYaxis()->SetTitleOffset(1.4);

   frame2->Draw();

   c->cd(3);

   gPad->SetLeftMargin(0.20);

   hh_cos->GetZaxis()->SetTitleOffset(2.3);

   hh_cos->Draw("surf");

   c->cd(4);

   gPad->SetLeftMargin(0.20);

   hh_sin->GetZaxis()->SetTitleOffset(2.3);

   hh_sin->Draw("surf");

}

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

RooDataSet.h

RooFormulaVar.h

RooGaussian.h

RooPlot.h

RooPolyVar.h

RooProduct.h

RooRealSumPdf.h

RooRealVar.h

kRed
@ kRed
Definition Rtypes.h:67

kBlue
@ kBlue
Definition Rtypes.h:67

kDashed
@ kDashed
Definition TAttLine.h:54

TAxis.h

TCanvas.h

TH1.h

gPad
#define gPad
Definition TVirtualPad.h:322

RooArgList
RooArgList is a container object that can hold multiple RooAbsArg objects.
Definition RooArgList.h:22

RooFormulaVar
A RooFormulaVar is a generic implementation of a real-valued object, which takes a RooArgList of serv...
Definition RooFormulaVar.h:30

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

RooPolyVar
A RooAbsReal implementing a polynomial in terms of a list of RooAbsReal coefficients.
Definition RooPolyVar.h:25

RooProduct
Represents the product of a given set of RooAbsReal objects.
Definition RooProduct.h:29

RooRealSumPdf
Implements a PDF constructed from a sum of functions:
Definition RooRealSumPdf.h:24

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

TAttLine::SetLineColor
virtual void SetLineColor(Color_t lcolor)
Set the line color.
Definition TAttLine.h:44

TCanvas
The Canvas class.
Definition TCanvas.h:23

TH1
TH1 is the base class of all histogram classes in ROOT.
Definition TH1.h:109

TH1::GetZaxis
TAxis * GetZaxis()
Definition TH1.h:573

TH1::Draw
void Draw(Option_t *option="") override
Draw this histogram with options.
Definition TH1.cxx:3097

RooFit::YVar
RooCmdArg YVar(const RooAbsRealLValue &var, const RooCmdArg &arg={})
Definition RooGlobalFunc.cxx:848

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

RooFit::Components
RooCmdArg Components(Args_t &&... argsOrArgSet)
Definition RooGlobalFunc.h:141

RooFit::Binning
RooCmdArg Binning(const RooAbsBinning &binning)
Definition RooGlobalFunc.cxx:317

RooFit::LineColor
RooCmdArg LineColor(TColorNumber color)
Definition RooGlobalFunc.cxx:229

RooFit::LineStyle
RooCmdArg LineStyle(Style_t style)
Definition RooGlobalFunc.cxx:233

f1
TF1 * f1
Definition legend1.C:11

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

rf503_wspaceread.data
data
Definition rf503_wspaceread.py:37

rf704_amplitudefit
Definition rf704_amplitudefit.py:1