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Reference Guide
rf314_paramfitrange.C
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1 /// \file
2 /// \ingroup tutorial_roofit
3 /// \notebook -js
4 /// 'MULTIDIMENSIONAL MODELS' RooFit tutorial macro #314
5 ///
6 /// Working with parametrized ranges in a fit. This an example of a
7 /// fit with an acceptance that changes per-event
8 ///
9 /// pdf = exp(-t/tau) with t[tmin,5]
10 ///
11 /// where t and tmin are both observables in the dataset
12 ///
13 /// \macro_image
14 /// \macro_output
15 /// \macro_code
16 /// \author 07/2008 - Wouter Verkerke
17 
18 
19 #include "RooRealVar.h"
20 #include "RooDataSet.h"
21 #include "RooGaussian.h"
22 #include "RooConstVar.h"
23 #include "RooExponential.h"
24 #include "TCanvas.h"
25 #include "TAxis.h"
26 #include "RooPlot.h"
27 #include "RooFitResult.h"
28 
29 using namespace RooFit ;
30 
31 
32 void rf314_paramfitrange()
33 {
34 
35  // D e f i n e o b s e r v a b l e s a n d d e c a y p d f
36  // ---------------------------------------------------------------
37 
38  // Declare observables
39  RooRealVar t("t","t",0,5) ;
40  RooRealVar tmin("tmin","tmin",0,0,5) ;
41 
42  // Make parametrized range in t : [tmin,5]
43  t.setRange(tmin,RooConst(t.getMax())) ;
44 
45  // Make pdf
46  RooRealVar tau("tau","tau",-1.54,-10,-0.1) ;
47  RooExponential model("model","model",t,tau) ;
48 
49 
50 
51  // C r e a t e i n p u t d a t a
52  // ------------------------------------
53 
54  // Generate complete dataset without acceptance cuts (for reference)
55  RooDataSet* dall = model.generate(t,10000) ;
56 
57  // Generate a (fake) prototype dataset for acceptance limit values
58  RooDataSet* tmp = RooGaussian("gmin","gmin",tmin,RooConst(0),RooConst(0.5)).generate(tmin,5000) ;
59 
60  // Generate dataset with t values that observe (t>tmin)
61  RooDataSet* dacc = model.generate(t,ProtoData(*tmp)) ;
62 
63 
64 
65  // F i t p d f t o d a t a i n a c c e p t a n c e r e g i o n
66  // -----------------------------------------------------------------------
67 
68  RooFitResult* r = model.fitTo(*dacc,Save()) ;
69 
70 
71 
72  // P l o t f i t t e d p d f o n f u l l a n d a c c e p t e d d a t a
73  // ---------------------------------------------------------------------------------
74 
75  // Make plot frame, add datasets and overlay model
76  RooPlot* frame = t.frame(Title("Fit to data with per-event acceptance")) ;
77  dall->plotOn(frame,MarkerColor(kRed),LineColor(kRed)) ;
78  model.plotOn(frame) ;
79  dacc->plotOn(frame) ;
80 
81  // Print fit results to demonstrate absence of bias
82  r->Print("v") ;
83 
84 
85  new TCanvas("rf314_paramranges","rf314_paramranges",600,600) ;
86  gPad->SetLeftMargin(0.15) ; frame->GetYaxis()->SetTitleOffset(1.6) ; frame->Draw() ;
87 
88  return ;
89 }
virtual void SetTitleOffset(Float_t offset=1)
Set distance between the axis and the axis title Offset is a correction factor with respect to the "s...
Definition: TAttAxis.cxx:294
TAxis * GetYaxis() const
Definition: RooPlot.cxx:1117
virtual RooPlot * plotOn(RooPlot *frame, const RooCmdArg &arg1=RooCmdArg::none(), const RooCmdArg &arg2=RooCmdArg::none(), const RooCmdArg &arg3=RooCmdArg::none(), const RooCmdArg &arg4=RooCmdArg::none(), const RooCmdArg &arg5=RooCmdArg::none(), const RooCmdArg &arg6=RooCmdArg::none(), const RooCmdArg &arg7=RooCmdArg::none(), const RooCmdArg &arg8=RooCmdArg::none()) const
Plot dataset on specified frame.
Definition: RooAbsData.cxx:568
RooCmdArg LineColor(Color_t color)
Definition: Rtypes.h:59
virtual void Print(Option_t *options=0) const
Print TNamed name and title.
Definition: RooFitResult.h:66
RooCmdArg Title(const char *name)
you should not use this method at all Int_t Int_t Double_t Double_t Double_t Int_t Double_t Double_t Double_t tau
Definition: TRolke.cxx:630
Plain Gaussian p.d.f.
Definition: RooGaussian.h:25
Exponential p.d.f.
RooRealVar represents a fundamental (non-derived) real valued object.
Definition: RooRealVar.h:36
ROOT::R::TRInterface & r
Definition: Object.C:4
RooDataSet is a container class to hold unbinned data.
Definition: RooDataSet.h:29
A RooPlot is a plot frame and a container for graphics objects within that frame. ...
Definition: RooPlot.h:41
The Canvas class.
Definition: TCanvas.h:31
RooCmdArg ProtoData(const RooDataSet &protoData, Bool_t randomizeOrder=kFALSE, Bool_t resample=kFALSE)
RooCmdArg Save(Bool_t flag=kTRUE)
RooConstVar & RooConst(Double_t val)
RooDataSet * generate(const RooArgSet &whatVars, Int_t nEvents, const RooCmdArg &arg1, const RooCmdArg &arg2=RooCmdArg::none(), const RooCmdArg &arg3=RooCmdArg::none(), const RooCmdArg &arg4=RooCmdArg::none(), const RooCmdArg &arg5=RooCmdArg::none())
Generate a new dataset containing the specified variables with events sampled from our distribution...
Definition: RooAbsPdf.cxx:1725
#define gPad
Definition: TVirtualPad.h:285
RooCmdArg MarkerColor(Color_t color)
virtual void Draw(Option_t *options=0)
Draw this plot and all of the elements it contains.
Definition: RooPlot.cxx:558