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rf305_condcorrprod.C
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1/// \file
2/// \ingroup tutorial_roofit
3/// \notebook
4/// Multidimensional models: multi-dimensional pdfs with conditional pdfs in product
5///
6/// pdf = gauss(x,f(y),sx | y ) * gauss(y,ms,sx) with f(y) = a0 + a1*y
7///
8/// \macro_image
9/// \macro_output
10/// \macro_code
11///
12/// \date July 2008
13/// \author Wouter Verkerke
14
15#include "RooRealVar.h"
16#include "RooDataSet.h"
17#include "RooGaussian.h"
18#include "RooConstVar.h"
19#include "RooPolyVar.h"
20#include "RooProdPdf.h"
21#include "RooPlot.h"
22#include "TCanvas.h"
23#include "TAxis.h"
24#include "TH1.h"
25using namespace RooFit;
26
28{
29 // C r e a t e c o n d i t i o n a l p d f g x ( x | y )
30 // -----------------------------------------------------------
31
32 // Create observables
33 RooRealVar x("x", "x", -5, 5);
34 RooRealVar y("y", "y", -5, 5);
35
36 // Create function f(y) = a0 + a1*y
37 RooRealVar a0("a0", "a0", -0.5, -5, 5);
38 RooRealVar a1("a1", "a1", -0.5, -1, 1);
39 RooPolyVar fy("fy", "fy", y, RooArgSet(a0, a1));
40
41 // Create gaussx(x,f(y),sx)
42 RooRealVar sigmax("sigma", "width of gaussian", 0.5);
43 RooGaussian gaussx("gaussx", "Gaussian in x with shifting mean in y", x, fy, sigmax);
44
45 // C r e a t e p d f g y ( y )
46 // -----------------------------------------------------------
47
48 // Create gaussy(y,0,5)
49 RooGaussian gaussy("gaussy", "Gaussian in y", y, RooConst(0), RooConst(3));
50
51 // C r e a t e p r o d u c t g x ( x | y ) * g y ( y )
52 // -------------------------------------------------------
53
54 // Create gaussx(x,sx|y) * gaussy(y)
55 RooProdPdf model("model", "gaussx(x|y)*gaussy(y)", gaussy, Conditional(gaussx, x));
56
57 // S a m p l e , f i t a n d p l o t p r o d u c t p d f
58 // ---------------------------------------------------------------
59
60 // Generate 1000 events in x and y from model
61 RooDataSet *data = model.generate(RooArgSet(x, y), 10000);
62
63 // Plot x distribution of data and projection of model on x = Int(dy) model(x,y)
64 RooPlot *xframe = x.frame();
65 data->plotOn(xframe);
66 model.plotOn(xframe);
67
68 // Plot x distribution of data and projection of model on y = Int(dx) model(x,y)
69 RooPlot *yframe = y.frame();
70 data->plotOn(yframe);
71 model.plotOn(yframe);
72
73 // Make two-dimensional plot in x vs y
74 TH1 *hh_model = model.createHistogram("hh_model", x, Binning(50), YVar(y, Binning(50)));
75 hh_model->SetLineColor(kBlue);
76
77 // Make canvas and draw RooPlots
78 TCanvas *c = new TCanvas("rf305_condcorrprod", "rf05_condcorrprod", 1200, 400);
79 c->Divide(3);
80 c->cd(1);
82 xframe->GetYaxis()->SetTitleOffset(1.6);
83 xframe->Draw();
84 c->cd(2);
86 yframe->GetYaxis()->SetTitleOffset(1.6);
87 yframe->Draw();
88 c->cd(3);
90 hh_model->GetZaxis()->SetTitleOffset(2.5);
91 hh_model->Draw("surf");
92}
#define c(i)
Definition RSha256.hxx:101
@ kBlue
Definition Rtypes.h:66
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
RooArgSet is a container object that can hold multiple RooAbsArg objects.
Definition RooArgSet.h:29
RooDataSet is a container class to hold unbinned data.
Definition RooDataSet.h:33
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
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
virtual void Draw(Option_t *options=0)
Draw this plot and all of the elements it contains.
Definition RooPlot.cxx:691
Class RooPolyVar is a RooAbsReal implementing a polynomial in terms of a list of RooAbsReal coefficie...
Definition RooPolyVar.h:28
RooProdPdf is an efficient implementation of a product of PDFs of the form.
Definition RooProdPdf.h:37
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
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:3073
RooCmdArg YVar(const RooAbsRealLValue &var, const RooCmdArg &arg=RooCmdArg::none())
RooConstVar & RooConst(Double_t val)
RooCmdArg Conditional(const RooArgSet &pdfSet, const RooArgSet &depSet, Bool_t depsAreCond=kFALSE)
RooCmdArg Binning(const RooAbsBinning &binning)
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...