JTestChi2_t.hh

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#ifndef __JTESTCHI2_T__
#define __JTESTCHI2_T__

#include <iostream>
#include "JTest_t.hh"

using namespace std;
/*
 * \author rgruiz
 */

/*
 * Implementation of the Chi2 test.
 */
class JTestChi2_t 
{ 
public:  

  /*
   * Default constructor.
   */  
  JTestChi2_t(){}

  /*
   * Tests the statistical compatibility of two ROOT TObjects
   * 
   * \param h1 First object
   * \param h2 Second object
   * \param threshold p-value
   *
   * \return Test result.
   */
  JTestResult JChi2Test(TH1* h1, TH1* h2, double threshold) {    
    
    JTestResult r;
    
    if(h1 -> GetNbinsX() != h2 -> GetNbinsX())
      ERROR("Histograms with different bining. The objects: " << h1 -> GetName() << " can not be compared." << endl);
        
    double chi2   = h1 -> Chi2Test (h2 , "WW");

    double M = h1->Integral();
    double N = h2->Integral();

    TH2D* h3 = (TH2D*)h1->Clone(h1->GetName()==h2->GetName() ?
                                MAKE_CSTRING(to_string(h1->GetName())) :
                                MAKE_CSTRING(to_string(h1->GetName()) + "_VS_" + to_string(h2->GetName())));
    
    h3->Reset();
    
    for (int i=1 ; i < h1->GetNbinsX() ; ++i){
    
      double m = h1->GetBinContent(i);
      double n = h2->GetBinContent(i);
      if(n!=0 && m!=0){

        double c = (M*n - N*m)/sqrt((n+m)*(N*M));       
        h3->SetBinContent(i,c);
      }
    }
      
    (chi2 < threshold ? r.passed = false : r.passed = true);

    r.message = MAKE_STRING(scientific << setprecision(2)<< "Test: " << "Chi2" <<
                            " HA: " << h1->GetUniqueID() << " " << h1->GetName() <<
                            " HB: " << h2->GetUniqueID() << " " << h2->GetName() <<
                            " Threshold: " << threshold << " Result: " << chi2 << " " << (r.passed ? "PASSED" : "FAILED"));


    JResultTitle title("Chi2_2D", "Deviation[#sigma] ", r.passed , chi2);
    
    h3->SetTitle(title.getTitle().c_str());
        
    r.obj = h3;

    return r;
  };

  /*
   * Tests the statistical compatibility of two ROOT TObjects
   * 
   * \param h1 First object
   * \param h2 Second object
   * \param outliersThreshold fraction of bins allowed to fail the test
   * \param chi2Threshold  p-value
   *
   * \return Test result.
   */
  JTestResult JChi2TestBin_2D(TH2* h1, TH2* h2, double outliersThreshold, double chi2Threshold) {    
      
    int nx1 = h1->GetNbinsX();
    int nx2 = h2->GetNbinsX();      
    int ny1 = h1->GetNbinsY();
    int ny2 = h2->GetNbinsY();
      
    double M = h1->Integral();
    double N = h2->Integral();

    if(nx1 != nx2 || ny1 != ny2 || M == 0 || N == 0)
      ERROR("Histograms with different binning. The objects: " << h1->GetName() << " can not be compared." << endl);
    
    TH2D* h3 = (TH2D*)h1->Clone(h1->GetName()==h2->GetName() ?
                                MAKE_CSTRING(to_string(h1->GetName())) :
                                MAKE_CSTRING(to_string(h1->GetName()) + "_VS_" + to_string(h2->GetName())));

    h3->Reset();

    JTestResult r;

    double outliers = 0;
    
    for (int i=1 ; i<nx1 ; ++i){
      for (int j=1 ; j<ny1 ; ++j){

        double m = h1 -> GetBinContent(i,j);
        double n = h2 -> GetBinContent(i,j);
        double chi2 = (n-m*N/M)/sqrt(m*N/M);
        (fabs(chi2) > chi2Threshold ? outliers+=1./(nx1*ny1) : outliers+=0 );
        h3->SetBinContent(i,j,chi2);
      }
    }
      
    (outliers > outliersThreshold ? r.passed = false : r.passed = true);
    
    r.message = MAKE_STRING(scientific << setprecision(2)<< "Test: " << "Chi2_bin" <<
                            " HA: " << h1->GetUniqueID() << " " << h1->GetName() <<
                            " HB: " << h2->GetUniqueID() << " " << h2->GetName() <<
                            " Threshold: " << outliersThreshold << " Result: " << outliers << " " << (r.passed ? "PASSED" : "FAILED"));

    JResultTitle title("Chi2_bin", "Outliers[%] ", r.passed , 100*outliers);
    
    h3->SetTitle(title.getTitle().c_str());
        
    r.obj = h3;

    return r;      
  };
}; 
  
#endif