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rf309_ndimplot.C
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1/// \file
2/// \ingroup tutorial_roofit
3/// \notebook
4/// Multidimensional models: making 2/3 dimensional plots of pdfs and datasets
5///
6/// \macro_image
7/// \macro_code
8/// \macro_output
9///
10/// \date July 2008
11/// \author Wouter Verkerke
12
13#include "RooRealVar.h"
14#include "RooDataSet.h"
15#include "RooGaussian.h"
16#include "RooProdPdf.h"
17#include "TCanvas.h"
18#include "TAxis.h"
19#include "TH1.h"
20#include "RooPlot.h"
21using namespace RooFit;
22
23void rf309_ndimplot()
24{
25
26 // C r e a t e 2 D m o d e l a n d d a t a s e t
27 // -----------------------------------------------------
28
29 // Create observables
30 RooRealVar x("x", "x", -5, 5);
31 RooRealVar y("y", "y", -5, 5);
32
33 // Create parameters
34 RooRealVar a0("a0", "a0", -3.5, -5, 5);
35 RooRealVar a1("a1", "a1", -1.5, -1, 1);
36 RooRealVar sigma("sigma", "width of gaussian", 1.5);
37
38 // Create interpreted function f(y) = a0 - a1*sqrt(10*abs(y))
39 RooFormulaVar fy("fy", "a0-a1*sqrt(10*abs(y))", RooArgSet(y, a0, a1));
40
41 // Create gauss(x,f(y),s)
42 RooGaussian model("model", "Gaussian with shifting mean", x, fy, sigma);
43
44 // Sample dataset from gauss(x,y)
45 std::unique_ptr<RooDataSet> data{model.generate({x, y}, 10000)};
46
47 // M a k e 2 D p l o t s o f d a t a a n d m o d e l
48 // -------------------------------------------------------------
49
50 // Create and fill ROOT 2D histogram (20x20 bins) with contents of dataset
51 TH1 *hh_data = data->createHistogram("x,y", Binning(20), Binning(20));
52
53 // Create and fill ROOT 2D histogram (50x50 bins) with sampling of pdf
54 // TH2D* hh_pdf = model.createHistogram("hh_model",x,Binning(50),YVar(y,Binning(50))) ;
55 TH1 *hh_pdf = model.createHistogram("x,y", 50, 50);
56 hh_pdf->SetLineColor(kBlue);
57
58 // C r e a t e 3 D m o d e l a n d d a t a s e t
59 // -----------------------------------------------------
60
61 // Create observables
62 RooRealVar z("z", "z", -5, 5);
63
64 RooGaussian gz("gz", "gz", z, 0.0, 2.0);
65 RooProdPdf model3("model3", "model3", RooArgSet(model, gz));
66
67 std::unique_ptr<RooDataSet> data3{model3.generate({x, y, z}, 10000)};
68
69 // M a k e 3 D p l o t s o f d a t a a n d m o d e l
70 // -------------------------------------------------------------
71
72 // Create and fill ROOT 2D histogram (8x8x8 bins) with contents of dataset
73 TH1 *hh_data3 = data3->createHistogram("hh_data3", x, Binning(8), YVar(y, Binning(8)), ZVar(z, Binning(8)));
74
75 // Create and fill ROOT 2D histogram (20x20x20 bins) with sampling of pdf
76 TH1 *hh_pdf3 = model3.createHistogram("hh_model3", x, Binning(20), YVar(y, Binning(20)), ZVar(z, Binning(20)));
77 hh_pdf3->SetFillColor(kBlue);
78
79 TCanvas *c1 = new TCanvas("rf309_2dimplot", "rf309_2dimplot", 800, 800);
80 c1->Divide(2, 2);
81 c1->cd(1);
83 hh_data->GetZaxis()->SetTitleOffset(1.4);
84 hh_data->Draw("lego");
85 c1->cd(2);
87 hh_pdf->GetZaxis()->SetTitleOffset(2.5);
88 hh_pdf->Draw("surf");
89 c1->cd(3);
91 hh_data->GetZaxis()->SetTitleOffset(1.4);
92 hh_data->Draw("box");
93 c1->cd(4);
95 hh_pdf->GetZaxis()->SetTitleOffset(2.5);
96 hh_pdf->Draw("cont3");
97
98 TCanvas *c2 = new TCanvas("rf309_3dimplot", "rf309_3dimplot", 800, 400);
99 c2->Divide(2);
100 c2->cd(1);
102 hh_data3->GetZaxis()->SetTitleOffset(1.4);
103 hh_data3->Draw("lego");
104 c2->cd(2);
106 hh_pdf3->GetZaxis()->SetTitleOffset(1.4);
107 hh_pdf3->Draw("iso");
108}
double fy() const
@ kBlue
Definition Rtypes.h:66
Option_t Option_t TPoint TPoint const char GetTextMagnitude GetFillStyle GetLineColor GetLineWidth GetMarkerStyle GetTextAlign GetTextColor GetTextSize void data
RooArgSet is a container object that can hold multiple RooAbsArg objects.
Definition RooArgSet.h:55
A RooFormulaVar is a generic implementation of a real-valued object, which takes a RooArgList of serv...
Plain Gaussian p.d.f.
Definition RooGaussian.h:24
Efficient implementation of a product of PDFs of the form.
Definition RooProdPdf.h:33
Variable that can be changed from the outside.
Definition RooRealVar.h:37
virtual void SetTitleOffset(Float_t offset=1)
Set distance between the axis and the axis title.
Definition TAttAxis.cxx:298
virtual void SetFillColor(Color_t fcolor)
Set the fill area color.
Definition TAttFill.h:37
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:59
TAxis * GetZaxis()
Definition TH1.h:326
void Draw(Option_t *option="") override
Draw this histogram with options.
Definition TH1.cxx:3066
RooCmdArg YVar(const RooAbsRealLValue &var, const RooCmdArg &arg={})
RooCmdArg ZVar(const RooAbsRealLValue &var, const RooCmdArg &arg={})
RooCmdArg Binning(const RooAbsBinning &binning)
const Double_t sigma
Double_t y[n]
Definition legend1.C:17
return c1
Definition legend1.C:41
Double_t x[n]
Definition legend1.C:17
return c2
Definition legend2.C:14
The namespace RooFit contains mostly switches that change the behaviour of functions of PDFs (or othe...
Definition JSONIO.h:26