 ROOT   Reference Guide rf302_utilfuncs.C
Go to the documentation of this file.
1/// \file
2/// \ingroup tutorial_roofit
3/// \notebook
4/// Multidimensional models: utility functions classes available for use in tailoring of
5/// composite (multidimensional) pdfs
6///
7/// \macro_image
8/// \macro_output
9/// \macro_code
10///
11/// \date July 2008
12/// \author Wouter Verkerke
13
14#include "RooRealVar.h"
15#include "RooDataSet.h"
16#include "RooGaussian.h"
17#include "TCanvas.h"
18#include "TAxis.h"
19#include "RooPlot.h"
20#include "RooFormulaVar.h"
22#include "RooProduct.h"
23#include "RooPolyVar.h"
24#include "TCanvas.h"
25#include "TAxis.h"
26#include "TH1.h"
27
28using namespace RooFit;
29
30void rf302_utilfuncs()
31{
32 // 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
33 // -----------------------------------------------------------
34
35 // Create observables
36 RooRealVar x("x", "x", -5, 5);
37 RooRealVar y("y", "y", -5, 5);
38
39 // Create parameters
40 RooRealVar a0("a0", "a0", -1.5, -5, 5);
41 RooRealVar a1("a1", "a1", -0.5, -1, 1);
42 RooRealVar sigma("sigma", "width of gaussian", 0.5);
43
44 // 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
45 // -----------------------------------------------------------------------
46
47 // Create interpreted function f(y) = a0 - a1*sqrt(10*abs(y))
48 RooFormulaVar fy_1("fy_1", "a0-a1*sqrt(10*abs(y))", RooArgSet(y, a0, a1));
49
50 // Create gauss(x,f(y),s)
51 RooGaussian model_1("model_1", "Gaussian with shifting mean", x, fy_1, sigma);
52
53 // 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
54 // -----------------------------------------------------------------------
55
56 // Create polynomial function f(y) = a0 + a1*y
57 RooPolyVar fy_2("fy_2", "fy_2", y, RooArgSet(a0, a1));
58
59 // Create gauss(x,f(y),s)
60 RooGaussian model_2("model_2", "Gaussian with shifting mean", x, fy_2, sigma);
61
62 // 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
63 // -----------------------------------------------------------------------
64
65 // Create sum function f(y) = a0 + y
66 RooAddition fy_3("fy_3", "a0+y", RooArgSet(a0, y));
67
68 // Create gauss(x,f(y),s)
69 RooGaussian model_3("model_3", "Gaussian with shifting mean", x, fy_3, sigma);
70
71 // 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
72 // -----------------------------------------------------------------------
73
74 // Create product function f(y) = a1*y
75 RooProduct fy_4("fy_4", "a1*y", RooArgSet(a1, y));
76
77 // Create gauss(x,f(y),s)
78 RooGaussian model_4("model_4", "Gaussian with shifting mean", x, fy_4, sigma);
79
80 // P l o t a l l p d f s
81 // ----------------------------
82
83 // Make two-dimensional plots in x vs y
84 TH1 *hh_model_1 = model_1.createHistogram("hh_model_1", x, Binning(50), YVar(y, Binning(50)));
85 TH1 *hh_model_2 = model_2.createHistogram("hh_model_2", x, Binning(50), YVar(y, Binning(50)));
86 TH1 *hh_model_3 = model_3.createHistogram("hh_model_3", x, Binning(50), YVar(y, Binning(50)));
87 TH1 *hh_model_4 = model_4.createHistogram("hh_model_4", x, Binning(50), YVar(y, Binning(50)));
88 hh_model_1->SetLineColor(kBlue);
89 hh_model_2->SetLineColor(kBlue);
90 hh_model_3->SetLineColor(kBlue);
91 hh_model_4->SetLineColor(kBlue);
92
93 // Make canvas and draw RooPlots
94 TCanvas *c = new TCanvas("rf302_utilfuncs", "rf302_utilfuncs", 800, 800);
95 c->Divide(2, 2);
96 c->cd(1);
98 hh_model_1->GetZaxis()->SetTitleOffset(2.5);
99 hh_model_1->Draw("surf");
100 c->cd(2);
102 hh_model_2->GetZaxis()->SetTitleOffset(2.5);
103 hh_model_2->Draw("surf");
104 c->cd(3);
106 hh_model_3->GetZaxis()->SetTitleOffset(2.5);
107 hh_model_3->Draw("surf");
108 c->cd(4);
110 hh_model_4->GetZaxis()->SetTitleOffset(2.5);
111 hh_model_4->Draw("surf");
112}
#define c(i)
Definition: RSha256.hxx:101
@ kBlue
Definition: Rtypes.h:66
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:35
A RooFormulaVar is a generic implementation of a real-valued object, which takes a RooArgList of serv...
Definition: RooFormulaVar.h:30
Plain Gaussian p.d.f.
Definition: RooGaussian.h:24
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:29
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:302
virtual void SetLineColor(Color_t lcolor)
Set the line color.
Definition: TAttLine.h:40
The Canvas class.
Definition: TCanvas.h:23
TH1 is the base class of all histogram classes in ROOT.
Definition: TH1.h:58
TAxis * GetZaxis()
Definition: TH1.h:322
virtual void Draw(Option_t *option="")
Draw this histogram with options.
Definition: TH1.cxx:3068
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...
Definition: Common.h:18