ROOT   Reference Guide
rf502_wspacewrite.C
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1/// \file
2/// \ingroup tutorial_roofit
3/// \notebook -nodraw
4///
5/// Organisation and simultaneous fits: creating and writing a workspace
6///
7/// \macro_output
8/// \macro_code
9///
10/// \date 07/2008
11/// \author Wouter Verkerke
12
13#include "RooRealVar.h"
14#include "RooDataSet.h"
15#include "RooGaussian.h"
16#include "RooConstVar.h"
17#include "RooChebychev.h"
19#include "RooWorkspace.h"
20#include "RooPlot.h"
21#include "TCanvas.h"
22#include "TAxis.h"
23#include "TFile.h"
24#include "TH1.h"
25using namespace RooFit;
26
28{
29 // C r e a t e m o d e l a n d d a t a s e t
30 // -----------------------------------------------
31
32 // Declare observable x
33 RooRealVar x("x", "x", 0, 10);
34
35 // Create two Gaussian PDFs g1(x,mean1,sigma) anf g2(x,mean2,sigma) and their parameters
36 RooRealVar mean("mean", "mean of gaussians", 5, 0, 10);
37 RooRealVar sigma1("sigma1", "width of gaussians", 0.5);
38 RooRealVar sigma2("sigma2", "width of gaussians", 1);
39
40 RooGaussian sig1("sig1", "Signal component 1", x, mean, sigma1);
41 RooGaussian sig2("sig2", "Signal component 2", x, mean, sigma2);
42
43 // Build Chebychev polynomial p.d.f.
44 RooRealVar a0("a0", "a0", 0.5, 0., 1.);
45 RooRealVar a1("a1", "a1", 0.2, 0, 1.);
46 RooChebychev bkg("bkg", "Background", x, RooArgSet(a0, a1));
47
48 // Sum the signal components into a composite signal p.d.f.
49 RooRealVar sig1frac("sig1frac", "fraction of component 1 in signal", 0.8, 0., 1.);
50 RooAddPdf sig("sig", "Signal", RooArgList(sig1, sig2), sig1frac);
51
52 // Sum the composite signal and background
53 RooRealVar bkgfrac("bkgfrac", "fraction of background", 0.5, 0., 1.);
54 RooAddPdf model("model", "g1+g2+a", RooArgList(bkg, sig), bkgfrac);
55
56 // Generate a data sample of 1000 events in x from model
57 RooDataSet *data = model.generate(x, 1000);
58
59 // C r e a t e w o r k s p a c e , i m p o r t d a t a a n d m o d e l
60 // -----------------------------------------------------------------------------
61
62 // Create a new empty workspace
63 RooWorkspace *w = new RooWorkspace("w", "workspace");
64
65 // Import model and all its components into the workspace
66 w->import(model);
67
68 // Import data into the workspace
69 w->import(*data);
70
71 // Print workspace contents
72 w->Print();
73
74 // S a v e w o r k s p a c e i n f i l e
75 // -------------------------------------------
76
77 // Save the workspace into a ROOT file
78 w->writeToFile("rf502_workspace.root");
79
80 // Workspace will remain in memory after macro finishes
82}
#define gDirectory
Definition: TDirectory.h:229
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
Plain Gaussian p.d.f.
Definition: RooGaussian.h:25
RooRealVar represents a variable that can be changed from the outside.
Definition: RooRealVar.h:35
The RooWorkspace is a persistable container for RooFit projects.
Definition: RooWorkspace.h:43
void Print(Option_t *opts=0) const
Print contents of the workspace.
Bool_t writeToFile(const char *fileName, Bool_t recreate=kTRUE)
Save this current workspace into given file.
Bool_t import(const RooAbsArg &arg, const RooCmdArg &arg1=RooCmdArg(), const RooCmdArg &arg2=RooCmdArg(), const RooCmdArg &arg3=RooCmdArg(), const RooCmdArg &arg4=RooCmdArg(), const RooCmdArg &arg5=RooCmdArg(), const RooCmdArg &arg6=RooCmdArg(), const RooCmdArg &arg7=RooCmdArg(), const RooCmdArg &arg8=RooCmdArg(), const RooCmdArg &arg9=RooCmdArg())
Import a RooAbsArg object, e.g.
Double_t x[n]
Definition: legend1.C:17
The namespace RooFit contains mostly switches that change the behaviour of functions of PDFs (or othe...