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Reference Guide
rf203_ranges.C
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1/// \file
2/// \ingroup tutorial_roofit
3/// \notebook -js
4/// Fitting and plotting in sub ranges.
5///
6/// \macro_image
7/// \macro_output
8/// \macro_code
9///
10/// \date July 2008
11/// \author Wouter Verkerke
12
13#include "RooRealVar.h"
14#include "RooDataSet.h"
15#include "RooGaussian.h"
16#include "RooConstVar.h"
17#include "RooPolynomial.h"
18#include "RooAddPdf.h"
19#include "RooFitResult.h"
20#include "RooPlot.h"
21#include "TCanvas.h"
22#include "TAxis.h"
23#include "TH1.h"
24using namespace RooFit;
25
26void rf203_ranges()
27{
28 // S e t u p m o d e l
29 // ---------------------
30
31 // Construct observables x
32 RooRealVar x("x", "x", -10, 10);
33
34 // Construct gaussx(x,mx,1)
35 RooRealVar mx("mx", "mx", 0, -10, 10);
36 RooGaussian gx("gx", "gx", x, mx, RooConst(1));
37
38 // Construct px = 1 (flat in x)
39 RooPolynomial px("px", "px", x);
40
41 // Construct model = f*gx + (1-f)px
42 RooRealVar f("f", "f", 0., 1.);
43 RooAddPdf model("model", "model", RooArgList(gx, px), f);
44
45 // Generated 10000 events in (x,y) from pdf model
46 RooDataSet *modelData = model.generate(x, 10000);
47
48 // F i t f u l l r a n g e
49 // ---------------------------
50
51 // Fit pdf to all data
52 RooFitResult *r_full = model.fitTo(*modelData, Save(kTRUE));
53
54 // F i t p a r t i a l r a n g e
55 // ----------------------------------
56
57 // Define "signal" range in x as [-3,3]
58 x.setRange("signal", -3, 3);
59
60 // Fit pdf only to data in "signal" range
61 RooFitResult *r_sig = model.fitTo(*modelData, Save(kTRUE), Range("signal"));
62
63 // P l o t / p r i n t r e s u l t s
64 // ---------------------------------------
65
66 // Make plot frame in x and add data and fitted model
67 RooPlot *frame = x.frame(Title("Fitting a sub range"));
68 modelData->plotOn(frame);
69 model.plotOn(frame, Range("Full"), LineStyle(kDashed), LineColor(kRed)); // Add shape in full ranged dashed
70 model.plotOn(frame); // By default only fitted range is shown
71
72 // Print fit results
73 cout << "result of fit on all data " << endl;
74 r_full->Print();
75 cout << "result of fit in in signal region (note increased error on signal fraction)" << endl;
76 r_sig->Print();
77
78 // Draw frame on canvas
79 new TCanvas("rf203_ranges", "rf203_ranges", 600, 600);
80 gPad->SetLeftMargin(0.15);
81 frame->GetYaxis()->SetTitleOffset(1.4);
82 frame->Draw();
83
84 return;
85}
#define f(i)
Definition: RSha256.hxx:104
const Bool_t kTRUE
Definition: RtypesCore.h:91
@ kRed
Definition: Rtypes.h:66
@ kDashed
Definition: TAttLine.h:48
#define gPad
Definition: TVirtualPad.h:287
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
RooAddPdf is an efficient implementation of a sum of PDFs of the form.
Definition: RooAddPdf.h:32
RooArgList is a container object that can hold multiple RooAbsArg objects.
Definition: RooArgList.h:21
RooDataSet is a container class to hold unbinned data.
Definition: RooDataSet.h:33
RooFitResult is a container class to hold the input and output of a PDF fit to a dataset.
Definition: RooFitResult.h:40
virtual void Print(Option_t *options=0) const
Print TNamed name and title.
Definition: RooFitResult.h:66
Plain Gaussian p.d.f.
Definition: RooGaussian.h:24
A RooPlot is a plot frame and a container for graphics objects within that frame.
Definition: RooPlot.h:44
TAxis * GetYaxis() const
Definition: RooPlot.cxx:1263
virtual void Draw(Option_t *options=0)
Draw this plot and all of the elements it contains.
Definition: RooPlot.cxx:691
RooPolynomial implements a polynomial p.d.f of the form.
Definition: RooPolynomial.h:28
RooRealVar represents a variable that can be changed from the outside.
Definition: RooRealVar.h:39
virtual void SetTitleOffset(Float_t offset=1)
Set distance between the axis and the axis title.
Definition: TAttAxis.cxx:293
The Canvas class.
Definition: TCanvas.h:23
RooConstVar & RooConst(Double_t val)
RooCmdArg Save(Bool_t flag=kTRUE)
RooCmdArg LineColor(Color_t color)
RooCmdArg LineStyle(Style_t style)
Double_t x[n]
Definition: legend1.C:17
The namespace RooFit contains mostly switches that change the behaviour of functions of PDFs (or othe...
const char * Title
Definition: TXMLSetup.cxx:68
Ta Range(0, 0, 1, 1)