ROOT   Reference Guide
rf302_utilfuncs.C
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1/// \file
2/// \ingroup tutorial_roofit
3/// \notebook
4///
5/// Multidimensional models: utility functions classes available for use in tailoring of
6/// composite (multidimensional) pdfs
7///
8/// \macro_image
9/// \macro_output
10/// \macro_code
11///
12/// \date 07/2008
13/// \author Wouter Verkerke
14
15#include "RooRealVar.h"
16#include "RooDataSet.h"
17#include "RooGaussian.h"
18#include "TCanvas.h"
19#include "TAxis.h"
20#include "RooPlot.h"
21#include "RooFormulaVar.h"
23#include "RooProduct.h"
24#include "RooPolyVar.h"
25#include "TCanvas.h"
26#include "TAxis.h"
27#include "TH1.h"
28
29using namespace RooFit;
30
31void rf302_utilfuncs()
32{
33 // C r e a t e o b s e r v a b l e s , p a r a m e t e r s
34 // -----------------------------------------------------------
35
36 // Create observables
37 RooRealVar x("x", "x", -5, 5);
38 RooRealVar y("y", "y", -5, 5);
39
40 // Create parameters
41 RooRealVar a0("a0", "a0", -1.5, -5, 5);
42 RooRealVar a1("a1", "a1", -0.5, -1, 1);
43 RooRealVar sigma("sigma", "width of gaussian", 0.5);
44
45 // U s i n g R o o F o r m u l a V a r t o t a i l o r p d f
46 // -----------------------------------------------------------------------
47
48 // Create interpreted function f(y) = a0 - a1*sqrt(10*abs(y))
49 RooFormulaVar fy_1("fy_1", "a0-a1*sqrt(10*abs(y))", RooArgSet(y, a0, a1));
50
51 // Create gauss(x,f(y),s)
52 RooGaussian model_1("model_1", "Gaussian with shifting mean", x, fy_1, sigma);
53
54 // U s i n g R o o P o l y V a r t o t a i l o r p d f
55 // -----------------------------------------------------------------------
56
57 // Create polynomial function f(y) = a0 + a1*y
58 RooPolyVar fy_2("fy_2", "fy_2", y, RooArgSet(a0, a1));
59
60 // Create gauss(x,f(y),s)
61 RooGaussian model_2("model_2", "Gaussian with shifting mean", x, fy_2, sigma);
62
63 // U s i n g R o o A d d i t i o n t o t a i l o r p d f
64 // -----------------------------------------------------------------------
65
66 // Create sum function f(y) = a0 + y
67 RooAddition fy_3("fy_3", "a0+y", RooArgSet(a0, y));
68
69 // Create gauss(x,f(y),s)
70 RooGaussian model_3("model_3", "Gaussian with shifting mean", x, fy_3, sigma);
71
72 // U s i n g R o o P r o d u c t t o t a i l o r p d f
73 // -----------------------------------------------------------------------
74
75 // Create product function f(y) = a1*y
76 RooProduct fy_4("fy_4", "a1*y", RooArgSet(a1, y));
77
78 // Create gauss(x,f(y),s)
79 RooGaussian model_4("model_4", "Gaussian with shifting mean", x, fy_4, sigma);
80
81 // P l o t a l l p d f s
82 // ----------------------------
83
84 // Make two-dimensional plots in x vs y
85 TH1 *hh_model_1 = model_1.createHistogram("hh_model_1", x, Binning(50), YVar(y, Binning(50)));
86 TH1 *hh_model_2 = model_2.createHistogram("hh_model_2", x, Binning(50), YVar(y, Binning(50)));
87 TH1 *hh_model_3 = model_3.createHistogram("hh_model_3", x, Binning(50), YVar(y, Binning(50)));
88 TH1 *hh_model_4 = model_4.createHistogram("hh_model_4", x, Binning(50), YVar(y, Binning(50)));
89 hh_model_1->SetLineColor(kBlue);
90 hh_model_2->SetLineColor(kBlue);
91 hh_model_3->SetLineColor(kBlue);
92 hh_model_4->SetLineColor(kBlue);
93
94 // Make canvas and draw RooPlots
95 TCanvas *c = new TCanvas("rf302_utilfuncs", "rf302_utilfuncs", 800, 800);
96 c->Divide(2, 2);
97 c->cd(1);
99 hh_model_1->GetZaxis()->SetTitleOffset(2.5);
100 hh_model_1->Draw("surf");
101 c->cd(2);
103 hh_model_2->GetZaxis()->SetTitleOffset(2.5);
104 hh_model_2->Draw("surf");
105 c->cd(3);
107 hh_model_3->GetZaxis()->SetTitleOffset(2.5);
108 hh_model_3->Draw("surf");
109 c->cd(4);
111 hh_model_4->GetZaxis()->SetTitleOffset(2.5);
112 hh_model_4->Draw("surf");
113}
#define c(i)
Definition: RSha256.hxx:101
@ kBlue
Definition: Rtypes.h:64
RooAddition calculates the sum of a set of RooAbsReal terms, or when constructed with two sets,...
RooArgSet is a container object that can hold multiple RooAbsArg objects.
Definition: RooArgSet.h:28
A RooFormulaVar is a generic implementation of a real-valued object, which takes a RooArgList of serv...
Definition: RooFormulaVar.h:29
Plain Gaussian p.d.f.
Definition: RooGaussian.h:25
Class RooPolyVar is a RooAbsReal implementing a polynomial in terms of a list of RooAbsReal coefficie...
Definition: RooPolyVar.h:28
A RooProduct represents the product of a given set of RooAbsReal objects.
Definition: RooProduct.h:30
RooRealVar represents a variable that can be changed from the outside.
Definition: RooRealVar.h:35
virtual void SetTitleOffset(Float_t offset=1)
Set distance between the axis and the axis title.
Definition: TAttAxis.cxx:294
virtual void SetLineColor(Color_t lcolor)
Set the line color.
Definition: TAttLine.h:40
The Canvas class.
Definition: TCanvas.h:27
The TH1 histogram class.
Definition: TH1.h:56
TAxis * GetZaxis()
Definition: TH1.h:318
virtual void Draw(Option_t *option="")
Draw this histogram with options.
Definition: TH1.cxx:2998
RooCmdArg YVar(const RooAbsRealLValue &var, const RooCmdArg &arg=RooCmdArg::none())
RooCmdArg Binning(const RooAbsBinning &binning)
const Double_t sigma
Double_t y[n]
Definition: legend1.C:17
Double_t x[n]
Definition: legend1.C:17
The namespace RooFit contains mostly switches that change the behaviour of functions of PDFs (or othe...