ROOT   Reference Guide
rf205_compplot.C
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1/// \file
2/// \ingroup tutorial_roofit
3/// \notebook -js -nodraw
4///
5/// Addition and convolution: options for plotting components of composite p.d.f.s.
6///
7/// \macro_image
8/// \macro_output
9/// \macro_code
10///
11/// \date 07/2008
12/// \author Wouter Verkerke
13
14#include "RooRealVar.h"
15#include "RooDataSet.h"
16#include "RooGaussian.h"
18#include "RooChebychev.h"
19#include "RooExponential.h"
20#include "TCanvas.h"
21#include "TAxis.h"
22#include "RooPlot.h"
23using namespace RooFit;
24
25void rf205_compplot()
26{
27 // S e t u p c o m p o s i t e p d f
28 // --------------------------------------
29
30 // Declare observable x
31 RooRealVar x("x", "x", 0, 10);
32
33 // Create two Gaussian PDFs g1(x,mean1,sigma) anf g2(x,mean2,sigma) and their parameters
34 RooRealVar mean("mean", "mean of gaussians", 5);
35 RooRealVar sigma1("sigma1", "width of gaussians", 0.5);
36 RooRealVar sigma2("sigma2", "width of gaussians", 1);
37 RooGaussian sig1("sig1", "Signal component 1", x, mean, sigma1);
38 RooGaussian sig2("sig2", "Signal component 2", x, mean, sigma2);
39
40 // Sum the signal components into a composite signal p.d.f.
41 RooRealVar sig1frac("sig1frac", "fraction of component 1 in signal", 0.8, 0., 1.);
42 RooAddPdf sig("sig", "Signal", RooArgList(sig1, sig2), sig1frac);
43
44 // Build Chebychev polynomial p.d.f.
45 RooRealVar a0("a0", "a0", 0.5, 0., 1.);
46 RooRealVar a1("a1", "a1", 0.2, 0., 1.);
47 RooChebychev bkg1("bkg1", "Background 1", x, RooArgSet(a0, a1));
48
49 // Build exponential pdf
50 RooRealVar alpha("alpha", "alpha", -1);
51 RooExponential bkg2("bkg2", "Background 2", x, alpha);
52
53 // Sum the background components into a composite background p.d.f.
54 RooRealVar bkg1frac("sig1frac", "fraction of component 1 in background", 0.2, 0., 1.);
55 RooAddPdf bkg("bkg", "Signal", RooArgList(bkg1, bkg2), sig1frac);
56
57 // Sum the composite signal and background
58 RooRealVar bkgfrac("bkgfrac", "fraction of background", 0.5, 0., 1.);
59 RooAddPdf model("model", "g1+g2+a", RooArgList(bkg, sig), bkgfrac);
60
61 // S e t u p b a s i c p l o t w i t h d a t a a n d f u l l p d f
62 // ------------------------------------------------------------------------------
63
64 // Generate a data sample of 1000 events in x from model
65 RooDataSet *data = model.generate(x, 1000);
66
67 // Plot data and complete PDF overlaid
68 RooPlot *xframe = x.frame(Title("Component plotting of pdf=(sig1+sig2)+(bkg1+bkg2)"));
69 data->plotOn(xframe);
70 model.plotOn(xframe);
71
72 // Clone xframe for use below
73 RooPlot *xframe2 = (RooPlot *)xframe->Clone("xframe2");
74
75 // M a k e c o m p o n e n t b y o b j e c t r e f e r e n c e
76 // --------------------------------------------------------------------
77
78 // Plot single background component specified by object reference
79 model.plotOn(xframe, Components(bkg), LineColor(kRed));
80
81 // Plot single background component specified by object reference
82 model.plotOn(xframe, Components(bkg2), LineStyle(kDashed), LineColor(kRed));
83
84 // Plot multiple background components specified by object reference
85 // Note that specified components may occur at any level in object tree
86 // (e.g bkg is component of 'model' and 'sig2' is component 'sig')
87 model.plotOn(xframe, Components(RooArgSet(bkg, sig2)), LineStyle(kDotted));
88
89 // M a k e c o m p o n e n t b y n a m e / r e g e x p
90 // ------------------------------------------------------------
91
92 // Plot single background component specified by name
93 model.plotOn(xframe2, Components("bkg"), LineColor(kCyan));
94
95 // Plot multiple background components specified by name
96 model.plotOn(xframe2, Components("bkg1,sig2"), LineStyle(kDotted), LineColor(kCyan));
97
98 // Plot multiple background components specified by regular expression on name
99 model.plotOn(xframe2, Components("sig*"), LineStyle(kDashed), LineColor(kCyan));
100
101 // Plot multiple background components specified by multiple regular expressions on name
102 model.plotOn(xframe2, Components("bkg1,sig*"), LineStyle(kDashed), LineColor(kYellow), Invisible());
103
104 // Draw the frame on the canvas
105 TCanvas *c = new TCanvas("rf205_compplot", "rf205_compplot", 800, 400);
106 c->Divide(2);
107 c->cd(1);
109 xframe->GetYaxis()->SetTitleOffset(1.4);
110 xframe->Draw();
111 c->cd(2);
113 xframe2->GetYaxis()->SetTitleOffset(1.4);
114 xframe2->Draw();
115 c->Draw();
116}
#define c(i)
Definition: RSha256.hxx:101
@ kRed
Definition: Rtypes.h:64
@ kCyan
Definition: Rtypes.h:64
@ kYellow
Definition: Rtypes.h:64
@ kDashed
Definition: TAttLine.h:48
@ kDotted
Definition: TAttLine.h:48
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
Calls RooPlot* plotOn(RooPlot* frame, const RooLinkedList& cmdList) const ;.
Definition: RooAbsData.cxx:546
RooAddPdf is an efficient implementation of a sum of PDFs of the form.
RooArgList is a container object that can hold multiple RooAbsArg objects.
Definition: RooArgList.h:21
RooArgSet is a container object that can hold multiple RooAbsArg objects.
Definition: RooArgSet.h:28
Chebychev polynomial p.d.f.
Definition: RooChebychev.h:25
RooDataSet is a container class to hold unbinned data.
Definition: RooDataSet.h:33
Exponential PDF.
Plain Gaussian p.d.f.
Definition: RooGaussian.h:25
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:1277
virtual void Draw(Option_t *options=0)
Draw this plot and all of the elements it contains.
Definition: RooPlot.cxx:712
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
The Canvas class.
Definition: TCanvas.h:27
virtual TObject * Clone(const char *newname="") const
Make a clone of an object using the Streamer facility.
Definition: TNamed.cxx:74
RooCmdArg Invisible(bool inv=true)
RooCmdArg Components(const RooArgSet &compSet)
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:67