Logo ROOT  
Reference Guide
rf314_paramfitrange.C
Go to the documentation of this file.
1 /// \file
2 /// \ingroup tutorial_roofit
3 /// \notebook -js
4 /// Multidimensional models: working with parametrized ranges in a fit.
5 /// This an example of a fit with an acceptance that changes per-event
6 ///
7 /// `pdf = exp(-t/tau)` with `t[tmin,5]`
8 ///
9 /// where `t` and `tmin` are both observables in the dataset
10 ///
11 /// \macro_image
12 /// \macro_output
13 /// \macro_code
14 ///
15 /// \date July 2008
16 /// \author Wouter Verkerke
17 
18 #include "RooRealVar.h"
19 #include "RooDataSet.h"
20 #include "RooGaussian.h"
21 #include "RooConstVar.h"
22 #include "RooExponential.h"
23 #include "TCanvas.h"
24 #include "TAxis.h"
25 #include "RooPlot.h"
26 #include "RooFitResult.h"
27 
28 using namespace RooFit;
29 
31 {
32 
33  // 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
34  // ---------------------------------------------------------------
35 
36  // Declare observables
37  RooRealVar t("t", "t", 0, 5);
38  RooRealVar tmin("tmin", "tmin", 0, 0, 5);
39 
40  // Make parametrized range in t : [tmin,5]
41  t.setRange(tmin, RooConst(t.getMax()));
42 
43  // Make pdf
44  RooRealVar tau("tau", "tau", -1.54, -10, -0.1);
45  RooExponential model("model", "model", t, tau);
46 
47  // C r e a t e i n p u t d a t a
48  // ------------------------------------
49 
50  // Generate complete dataset without acceptance cuts (for reference)
51  RooDataSet *dall = model.generate(t, 10000);
52 
53  // Generate a (fake) prototype dataset for acceptance limit values
54  RooDataSet *tmp = RooGaussian("gmin", "gmin", tmin, RooConst(0), RooConst(0.5)).generate(tmin, 5000);
55 
56  // Generate dataset with t values that observe (t>tmin)
57  RooDataSet *dacc = model.generate(t, ProtoData(*tmp));
58 
59  // 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
60  // -----------------------------------------------------------------------
61 
62  RooFitResult *r = model.fitTo(*dacc, Save());
63 
64  // 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
65  // ---------------------------------------------------------------------------------
66 
67  // Make plot frame, add datasets and overlay model
68  RooPlot *frame = t.frame(Title("Fit to data with per-event acceptance"));
69  dall->plotOn(frame, MarkerColor(kRed), LineColor(kRed));
70  model.plotOn(frame);
71  dacc->plotOn(frame);
72 
73  // Print fit results to demonstrate absence of bias
74  r->Print("v");
75 
76  new TCanvas("rf314_paramranges", "rf314_paramranges", 600, 600);
77  gPad->SetLeftMargin(0.15);
78  frame->GetYaxis()->SetTitleOffset(1.6);
79  frame->Draw();
80 
81  return;
82 }
rf314_paramfitrange
Definition: rf314_paramfitrange.py:1
RooPlot::Draw
virtual void Draw(Option_t *options=0)
Draw this plot and all of the elements it contains.
Definition: RooPlot.cxx:691
TObject::Print
virtual void Print(Option_t *option="") const
This method must be overridden when a class wants to print itself.
Definition: TObject.cxx:552
r
ROOT::R::TRInterface & r
Definition: Object.C:4
RooGaussian.h
RooGaussian
Plain Gaussian p.d.f.
Definition: RooGaussian.h:24
TCanvas.h
RooDataSet.h
RooFitResult
RooFitResult is a container class to hold the input and output of a PDF fit to a dataset.
Definition: RooFitResult.h:40
RooPlot::frame
static RooPlot * frame(const RooAbsRealLValue &var, Double_t xmin, Double_t xmax, Int_t nBins)
Create a new frame for a given variable in x.
Definition: RooPlot.cxx:249
RooFit::ProtoData
RooCmdArg ProtoData(const RooDataSet &protoData, Bool_t randomizeOrder=kFALSE, Bool_t resample=kFALSE)
Definition: RooGlobalFunc.cxx:234
RooFit
The namespace RooFit contains mostly switches that change the behaviour of functions of PDFs (or othe...
Definition: RooCFunction1Binding.h:29
RooAbsData::plotOn
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
Definition: RooAbsData.cxx:547
RooPlot.h
RooPlot::GetYaxis
TAxis * GetYaxis() const
Definition: RooPlot.cxx:1258
RooPlot
A RooPlot is a plot frame and a container for graphics objects within that frame.
Definition: RooPlot.h:44
RooRealVar.h
kRed
@ kRed
Definition: Rtypes.h:66
RooFitResult.h
RooExponential.h
RooConstVar.h
RooFit::LineColor
RooCmdArg LineColor(Color_t color)
Definition: RooGlobalFunc.cxx:57
TCanvas
The Canvas class.
Definition: TCanvas.h:23
RooAbsPdf::generate
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())
See RooAbsPdf::generate(const RooArgSet&,const RooCmdArg&,const RooCmdArg&,const RooCmdArg&,...
Definition: RooAbsPdf.h:58
TAxis.h
gPad
#define gPad
Definition: TVirtualPad.h:287
RooDataSet
RooDataSet is a container class to hold unbinned data.
Definition: RooDataSet.h:33
make_cnn_model.model
model
Definition: make_cnn_model.py:6
RooFit::MarkerColor
RooCmdArg MarkerColor(Color_t color)
Definition: RooGlobalFunc.cxx:88
TAttAxis::SetTitleOffset
virtual void SetTitleOffset(Float_t offset=1)
Set distance between the axis and the axis title.
Definition: TAttAxis.cxx:293
RooRealVar
RooRealVar represents a variable that can be changed from the outside.
Definition: RooRealVar.h:37
RooFit::Save
RooCmdArg Save(Bool_t flag=kTRUE)
Definition: RooGlobalFunc.cxx:190
RooExponential
Exponential PDF.
Definition: RooExponential.h:25
RooFit::Title
RooCmdArg Title(const char *name)
Definition: RooGlobalFunc.cxx:176
RooFit::RooConst
RooConstVar & RooConst(Double_t val)
Definition: RooGlobalFunc.cxx:347