GSI Object Oriented Online Offline (Go4)  GO4-6.2.0
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Example3.cxx
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1 // $Id: Example3.cxx 3058 2021-03-12 11:01:32Z linev $
2 //-----------------------------------------------------------------------
3 // The GSI Online Offline Object Oriented (Go4) Project
4 // Experiment Data Processing at EE department, GSI
5 //-----------------------------------------------------------------------
6 // Copyright (C) 2000- GSI Helmholtzzentrum fuer Schwerionenforschung GmbH
7 // Planckstr. 1, 64291 Darmstadt, Germany
8 // Contact: http://go4.gsi.de
9 //-----------------------------------------------------------------------
10 // This software can be used under the license agreements as stated
11 // in Go4License.txt file which is part of the distribution.
12 //-----------------------------------------------------------------------
13 
14 // Go4Fit Examples N3
15 
16 #ifndef __CINT__
17 
18 #include <iostream>
19 
20 #include "TH1.h"
21 #include "TFile.h"
22 #include "TApplication.h"
23 
24 #include "TGo4Fitter.h"
25 #include "TGo4FitModelFunction.h"
26 
27 void Example3();
28 
29 int main(int argc, char **argv)
30 {
31  TApplication theApp("Application", 0, 0);
32 
33  Example3();
34 
35  theApp.Run();
36 
37  return 0;
38 }
39 
40 extern "C" Double_t gaussian_(Double_t *axis, Double_t *pars);
41 
42 // routine to read histogram from examples file
43 TH1D* GetHistogram(const char* HistogramName)
44 {
45  TFile *f1 = TFile::Open("histograms.root");
46  if (f1==0) return 0;
47  TH1D *histo = 0;
48  f1->GetObject(HistogramName, histo);
49  if (histo) histo->SetDirectory(0);
50  return histo;
51 }
52 
53 void Example3()
54 {
55 // create fitter, select fit function and add standard actions list
56  TGo4Fitter fitter("Fitter", TGo4Fitter::ff_ML_Poisson, kTRUE);
57 
58 // add histogram to fitter, which should be fitted
59  fitter.AddH1("data1", GetHistogram("hDeg120_P_c"), kTRUE, 2200., 2900.);
60 
61 // create polynom of first order
62  fitter.AddPolynomX( "data1", "Pol", 1);
63 
64 // create model, which uses user function to calculate gaussian shape
65  fitter.AddModel( "data1", new TGo4FitModelFunction("Gauss1",&gaussian_,2,kTRUE) );
66  fitter.AddModel( "data1", new TGo4FitModelFunction("Gauss2",&gaussian_,2,kTRUE) );
67 
68 // set initial values of user model parameters
69  fitter.SetParValue("Gauss1.Par0",2553.);
70  fitter.SetParValue("Gauss1.Par1",15.);
71  fitter.SetParValue("Gauss2.Par0",2672.);
72  fitter.SetParValue("Gauss2.Par1",15.);
73 
74 // add output actions
75  fitter.AddOutputAction("Draw","#data1,Gauss1,Gauss2");
76  fitter.AddOutputAction("Print","Pars");
77 
78 // perform all actions
79  fitter.DoActions();
80 }
81 
82 #else
83 
84 void Example3()
85 {
86  std::cout << "This example uses linked FORTRAN library," << std::endl;
87  std::cout << "therefore it can not be run in CINT" << std::endl;
88 }
89 
90 #endif
91 
Bool_t SetParValue(const char *ParName, Double_t iValue)
int main(int argc, char **argv)
Definition: Example3.cxx:29
TH1D * GetHistogram(const char *HistogramName)
Definition: Example3.cxx:43
Double_t gaussian_(Double_t *axis, Double_t *pars)
void AddPolynomX(const char *DataName, const char *NamePrefix, Int_t MaxOrder=1, Int_t GroupIndex=0, Double_t lrange=0., Double_t rrange=0.)
Definition: TGo4Fitter.cxx:223
TGo4FitterOutput * AddOutputAction(const char *Action, const char *Option=0)
void Example3()
Definition: Example3.cxx:53
void DoActions(Bool_t AllowFitterChange=kFALSE, TObjArray *Actions=0)
TGo4FitModel * AddModel(TGo4FitModel *m)
Definition: TGo4Fitter.cxx:201
TGo4FitDataHistogram * AddH1(const char *DataName, TH1 *histo, Bool_t Owned=kFALSE, Double_t lrange=0., Double_t rrange=0.)
Definition: TGo4Fitter.cxx:124