Logo ROOT  
Reference Guide
rf605_profilell.C
Go to the documentation of this file.
1 /// \file
2 /// \ingroup tutorial_roofit
3 /// \notebook -js
4 ///
5 /// Likelihood and minimization: working with the profile likelihood estimator
6 ///
7 /// \macro_image
8 /// \macro_output
9 /// \macro_code
10 ///
11 /// \date 07/2008
12 /// \author Wouter Verkerke
13 
14 #include "RooRealVar.h"
15 #include "RooDataSet.h"
16 #include "RooGaussian.h"
17 #include "RooConstVar.h"
18 #include "RooAddPdf.h"
19 #include "RooMinimizer.h"
20 #include "TCanvas.h"
21 #include "TAxis.h"
22 #include "RooPlot.h"
23 using namespace RooFit;
24 
25 void rf605_profilell()
26 {
27  // C r e a t e m o d e l a n d d a t a s e t
28  // -----------------------------------------------
29 
30  // Observable
31  RooRealVar x("x", "x", -20, 20);
32 
33  // Model (intentional strong correlations)
34  RooRealVar mean("mean", "mean of g1 and g2", 0, -10, 10);
35  RooRealVar sigma_g1("sigma_g1", "width of g1", 3);
36  RooGaussian g1("g1", "g1", x, mean, sigma_g1);
37 
38  RooRealVar sigma_g2("sigma_g2", "width of g2", 4, 3.0, 6.0);
39  RooGaussian g2("g2", "g2", x, mean, sigma_g2);
40 
41  RooRealVar frac("frac", "frac", 0.5, 0.0, 1.0);
42  RooAddPdf model("model", "model", RooArgList(g1, g2), frac);
43 
44  // Generate 1000 events
45  RooDataSet *data = model.generate(x, 1000);
46 
47  // C o n s t r u c t p l a i n l i k e l i h o o d
48  // ---------------------------------------------------
49 
50  // Construct unbinned likelihood
51  RooAbsReal *nll = model.createNLL(*data, NumCPU(2));
52 
53  // Minimize likelihood w.r.t all parameters before making plots
54  RooMinimizer(*nll).migrad();
55 
56  // Plot likelihood scan frac
57  RooPlot *frame1 = frac.frame(Bins(10), Range(0.01, 0.95), Title("LL and profileLL in frac"));
58  nll->plotOn(frame1, ShiftToZero());
59 
60  // Plot likelihood scan in sigma_g2
61  RooPlot *frame2 = sigma_g2.frame(Bins(10), Range(3.3, 5.0), Title("LL and profileLL in sigma_g2"));
62  nll->plotOn(frame2, ShiftToZero());
63 
64  // C o n s t r u c t p r o f i l e l i k e l i h o o d i n f r a c
65  // -----------------------------------------------------------------------
66 
67  // The profile likelihood estimator on nll for frac will minimize nll w.r.t
68  // all floating parameters except frac for each evaluation
69 
70  RooAbsReal *pll_frac = nll->createProfile(frac);
71 
72  // Plot the profile likelihood in frac
73  pll_frac->plotOn(frame1, LineColor(kRed));
74 
75  // Adjust frame maximum for visual clarity
76  frame1->SetMinimum(0);
77  frame1->SetMaximum(3);
78 
79  // C o n s t r u c t p r o f i l e l i k e l i h o o d i n s i g m a _ g 2
80  // -------------------------------------------------------------------------------
81 
82  // The profile likelihood estimator on nll for sigma_g2 will minimize nll
83  // w.r.t all floating parameters except sigma_g2 for each evaluation
84  RooAbsReal *pll_sigmag2 = nll->createProfile(sigma_g2);
85 
86  // Plot the profile likelihood in sigma_g2
87  pll_sigmag2->plotOn(frame2, LineColor(kRed));
88 
89  // Adjust frame maximum for visual clarity
90  frame2->SetMinimum(0);
91  frame2->SetMaximum(3);
92 
93  // Make canvas and draw RooPlots
94  TCanvas *c = new TCanvas("rf605_profilell", "rf605_profilell", 800, 400);
95  c->Divide(2);
96  c->cd(1);
97  gPad->SetLeftMargin(0.15);
98  frame1->GetYaxis()->SetTitleOffset(1.4);
99  frame1->Draw();
100  c->cd(2);
101  gPad->SetLeftMargin(0.15);
102  frame2->GetYaxis()->SetTitleOffset(1.4);
103  frame2->Draw();
104 
105  delete pll_frac;
106  delete pll_sigmag2;
107  delete nll;
108 }
c
#define c(i)
Definition: RSha256.hxx:119
RooPlot::Draw
virtual void Draw(Option_t *options=0)
Draw this plot and all of the elements it contains.
Definition: RooPlot.cxx:691
RooAddPdf
Definition: RooAddPdf.h:32
RooFit::Bins
RooCmdArg Bins(Int_t nbin)
Definition: RooGlobalFunc.cxx:174
RooArgList
Definition: RooArgList.h:21
RooGaussian.h
RooFit::ShiftToZero
RooCmdArg ShiftToZero()
Definition: RooGlobalFunc.cxx:50
RooPlot::SetMaximum
virtual void SetMaximum(Double_t maximum=-1111)
Set maximum value of Y axis.
Definition: RooPlot.cxx:1081
RooMinimizer::migrad
Int_t migrad()
Execute MIGRAD.
Definition: RooMinimizer.cxx:344
x
Double_t x[n]
Definition: legend1.C:17
RooGaussian
Definition: RooGaussian.h:25
RooAddPdf.h
RooAbsReal
Definition: RooAbsReal.h:61
TCanvas.h
RooDataSet.h
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
Definition: RooCFunction1Binding.h:29
RooPlot.h
RooPlot::GetYaxis
TAxis * GetYaxis() const
Definition: RooPlot.cxx:1256
RooPlot
Definition: RooPlot.h:44
RooRealVar.h
kRed
@ kRed
Definition: Rtypes.h:66
RooConstVar.h
RooAbsReal::plotOn
virtual RooPlot * plotOn(RooPlot *frame, const RooCmdArg &arg1=RooCmdArg(), const RooCmdArg &arg2=RooCmdArg(), const RooCmdArg &arg3=RooCmdArg(), const RooCmdArg &arg4=RooCmdArg(), const RooCmdArg &arg5=RooCmdArg(), const RooCmdArg &arg6=RooCmdArg(), const RooCmdArg &arg7=RooCmdArg(), const RooCmdArg &arg8=RooCmdArg(), const RooCmdArg &arg9=RooCmdArg(), const RooCmdArg &arg10=RooCmdArg()) const
Plot (project) PDF on specified frame.
Definition: RooAbsReal.cxx:1714
RooAbsReal::createProfile
virtual RooAbsReal * createProfile(const RooArgSet &paramsOfInterest)
Create a RooProfileLL object that eliminates all nuisance parameters in the present function.
Definition: RooAbsReal.cxx:516
RooFit::NumCPU
RooCmdArg NumCPU(Int_t nCPU, Int_t interleave=0)
Definition: RooGlobalFunc.cxx:157
RooFit::LineColor
RooCmdArg LineColor(Color_t color)
Definition: RooGlobalFunc.cxx:56
TCanvas
Definition: TCanvas.h:23
RooMinimizer.h
TAxis.h
RooFit::Range
RooCmdArg Range(const char *rangeName, Bool_t adjustNorm=kTRUE)
Definition: RooGlobalFunc.cxx:52
RooPlot::SetMinimum
virtual void SetMinimum(Double_t minimum=-1111)
Set minimum value of Y axis.
Definition: RooPlot.cxx:1091
gPad
#define gPad
Definition: TVirtualPad.h:287
RooDataSet
Definition: RooDataSet.h:33
make_cnn_model.model
model
Definition: make_cnn_model.py:6
TAttAxis::SetTitleOffset
virtual void SetTitleOffset(Float_t offset=1)
Set distance between the axis and the axis title.
Definition: TAttAxis.cxx:293
RooRealVar
Definition: RooRealVar.h:35
RooMinimizer
Definition: RooMinimizer.h:40
RooFit::Title
RooCmdArg Title(const char *name)
Definition: RooGlobalFunc.cxx:173