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rf502_wspacewrite.C
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1/// \file
2/// \ingroup tutorial_roofit
3/// \notebook -nodraw
4/// Organisation and simultaneous fits: creating and writing a workspace
5///
6/// \macro_output
7/// \macro_code
8///
9/// \date July 2008
10/// \author Wouter Verkerke
11
12#include "RooRealVar.h"
13#include "RooDataSet.h"
14#include "RooGaussian.h"
15#include "RooConstVar.h"
16#include "RooChebychev.h"
17#include "RooAddPdf.h"
18#include "RooWorkspace.h"
19#include "RooPlot.h"
20#include "TCanvas.h"
21#include "TAxis.h"
22#include "TFile.h"
23#include "TH1.h"
24using namespace RooFit;
25
27{
28 // C r e a t e m o d e l a n d d a t a s e t
29 // -----------------------------------------------
30
31 // Declare observable x
32 RooRealVar x("x", "x", 0, 10);
33
34 // Create two Gaussian PDFs g1(x,mean1,sigma) anf g2(x,mean2,sigma) and their parameters
35 RooRealVar mean("mean", "mean of gaussians", 5, 0, 10);
36 RooRealVar sigma1("sigma1", "width of gaussians", 0.5);
37 RooRealVar sigma2("sigma2", "width of gaussians", 1);
38
39 RooGaussian sig1("sig1", "Signal component 1", x, mean, sigma1);
40 RooGaussian sig2("sig2", "Signal component 2", x, mean, sigma2);
41
42 // Build Chebychev polynomial pdf
43 RooRealVar a0("a0", "a0", 0.5, 0., 1.);
44 RooRealVar a1("a1", "a1", 0.2, 0, 1.);
45 RooChebychev bkg("bkg", "Background", x, RooArgSet(a0, a1));
46
47 // Sum the signal components into a composite signal pdf
48 RooRealVar sig1frac("sig1frac", "fraction of component 1 in signal", 0.8, 0., 1.);
49 RooAddPdf sig("sig", "Signal", RooArgList(sig1, sig2), sig1frac);
50
51 // Sum the composite signal and background
52 RooRealVar bkgfrac("bkgfrac", "fraction of background", 0.5, 0., 1.);
53 RooAddPdf model("model", "g1+g2+a", RooArgList(bkg, sig), bkgfrac);
54
55 // Generate a data sample of 1000 events in x from model
56 RooDataSet *data = model.generate(x, 1000);
57
58 // 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
59 // -----------------------------------------------------------------------------
60
61 // Create a new empty workspace
62 RooWorkspace *w = new RooWorkspace("w", "workspace");
63
64 // Import model and all its components into the workspace
65 w->import(model);
66
67 // Import data into the workspace
68 w->import(*data);
69
70 // Print workspace contents
71 w->Print();
72
73 // S a v e w o r k s p a c e i n f i l e
74 // -------------------------------------------
75
76 // Save the workspace into a ROOT file
77 w->writeToFile("rf502_workspace.root");
78
79 // Workspace will remain in memory after macro finishes
80 gDirectory->Add(w);
81}
#define gDirectory
Definition TDirectory.h:290
RooAddPdf is an efficient implementation of a sum of PDFs of the form.
Definition RooAddPdf.h:32
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:29
Chebychev polynomial p.d.f.
RooDataSet is a container class to hold unbinned data.
Definition RooDataSet.h:33
Plain Gaussian p.d.f.
Definition RooGaussian.h:24
RooRealVar represents a variable that can be changed from the outside.
Definition RooRealVar.h:39
The RooWorkspace is a persistable container for RooFit projects.
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...