JCOMPAREHISTOGRAMS::JTestKolmogorov_1D Class Reference

Implementation of the Kolmogorov test for 1D histograms. More...

#include <JTestKolmogorov_1D.hh>

Inheritance diagram for JCOMPAREHISTOGRAMS::JTestKolmogorov_1D:

Public Member Functions
	JTestKolmogorov_1D ()
	Default constructor.
void	test (const TObject *o1, const TObject *o2) override
	Applies Kolmogorov test for two ROOT TH1 histograms.
std::istream &	read (std::istream &in) override
	Read test parameters from input.
virtual std::ostream &	write (std::ostream &out, const char delimiter=' ', const bool onlyFailures=false) const
	Write test result to output.
virtual void	save (TFile *f, const std::string &path, const bool onlyFailures=false) const
	Writes the test result to root file.
const std::string &	getTestName () const
	Get test name.
const std::string &	getResultType () const
	Get result type.

Protected Attributes
const std::string	testName
	test name
const std::string	resultType
	test result type

Private Attributes
double	threshold
	threshold p-value to decide if test is passed.

Detailed Description

Implementation of the Kolmogorov test for 1D histograms.

This class is derived from the abstract class JTest_t(). For a general description of the implementation of this and other tests derived from JTest_t(), see its documentation.
This test uses the input parameter threshold() to evaluate whether the test is passed or failed.
The evaluation is done by comparing the threshold value with the result of the JKolmogorovTest() test. This is a p-value.
The parameter threshold should therefore be a real value between 0 and 1.

Definition at line 32 of file JTestKolmogorov_1D.hh.

Constructor & Destructor Documentation

JTestKolmogorov_1D()

JCOMPAREHISTOGRAMS::JTestKolmogorov_1D::JTestKolmogorov_1D ( )

inline

Default constructor.

Definition at line 40 of file JTestKolmogorov_1D.hh.

                         :
      JTest_t("KS_1D", "p-Value(KS)")
    {}

Member Function Documentation

test()

void JCOMPAREHISTOGRAMS::JTestKolmogorov_1D::test ( const TObject * o1, const TObject * o2 )

inlineoverridevirtual

Applies Kolmogorov test for two ROOT TH1 histograms.

Parameters

o1	First histogram
o2	Second histogram

Implements JCOMPAREHISTOGRAMS::JTest_t.

Definition at line 51 of file JTestKolmogorov_1D.hh.

    {    
      using namespace std;
      using namespace JPP;
 
      const TH1* h1 =  dynamic_cast<const TH1*>(o1);
      const TH1* h2 =  dynamic_cast<const TH1*>(o2);
    
      if (h1->GetDimension() != 1 || h2->GetDimension() != 1) {
        THROW(JValueOutOfRange, "JTestKolmogorov_1D::test(): Given histograms must be 1-D.");
      }
 
      const int n1 = h1 -> GetNbinsX();
      const int n2 = h2 -> GetNbinsX();
 
      if(n1 != n2) {
        THROW(JValueOutOfRange, "JTestKolmogorov_1D::test(): Histograms with different bining. The objects: " <<
              h1->GetName() << " and " << h2->GetName() << " can not be compared." << endl);
      }
 
      TH1* h3 = (TH1*) h1->Clone(h1->GetName() == h2->GetName() ?
                                 MAKE_CSTRING(h1->GetName()                            << "_" << testName) :
                                 MAKE_CSTRING(h1->GetName() << "_VS_" << h2->GetName() << "_" << testName));
      
      const double s1 = 1./h1->Integral();
      const double s2 = 1./h2->Integral();
 
      double ew1, ew2, w1 = 0, w2 = 0;
 
      for (int bin = 1; bin <= n1; ++bin){
        ew1 = h1->GetBinError(bin);
        ew2 = h2->GetBinError(bin);
        w1 += ew1*ew1;
        w2 += ew2*ew2;
      }
 
      bool afunc1 = false;
      bool afunc2 = false;
    
      double esum1 = 0, esum2 = 0;
      
      if (w1 > 0) {
        esum1 = 1./s1/s1/w1;
      } else {
        afunc1 = true;
      }
      
      if (w2 > 0) {
        esum2 = 1./s2/s2/w2;
      } else {
        afunc2 = true;
      }
      
      if (afunc2 && afunc1) {
        THROW(JValueOutOfRange, "JTestKolmogorov_1D::test(): Errors are zero for both histograms.");
      }
 
      double dmax = 0, c1 = 0, c2 = 0;
      
      for (int bin=1 ; bin<=n1 ; ++bin) {
        
        c1 += s1*h1->GetBinContent(bin);
        c2 += s2*h2->GetBinContent(bin);
        
        double d = TMath::Abs(c1-c2)*TMath::Sqrt(esum1*esum2/(esum1+esum2));
        double p = TMath::KolmogorovProb(d);
        
        dmax = TMath::Max(dmax,TMath::Abs(c1-c2));
        
        h3->SetBinContent(bin,p);
      }
 
      double z;
    
      if  (afunc1) {
        z = dmax*TMath::Sqrt(esum2);
      } else if (afunc2) {
        z = dmax*TMath::Sqrt(esum1);
      } else {
        z = dmax*TMath::Sqrt(esum1*esum2/(esum1+esum2));
      }
    
      const double pValue = TMath::KolmogorovProb(z);
 
      const bool passed = (pValue > threshold);
 
      const JResultTitle title(testName, resultType, passed , pValue);
      
      h3->SetTitle(title.getTitle().c_str());
      h3->GetYaxis()->SetTitle(resultType.c_str());      
    
      const JTestResult r (testName,
                           JRootObjectID(MAKE_STRING(h1->GetDirectory()->GetPath() << h1->GetName())),
                           JRootObjectID(MAKE_STRING(h2->GetDirectory()->GetPath() << h1->GetName())),
                           resultType, pValue, threshold, h3, passed);
  
      this->push_back(r);
    }

read()

std::istream & JCOMPAREHISTOGRAMS::JTestKolmogorov_1D::read ( std::istream & in )

inlineoverridevirtual

Read test parameters from input.

Parameters

in	input stream

Returns

input stream

Implements JCOMPAREHISTOGRAMS::JTest_t.

Definition at line 157 of file JTestKolmogorov_1D.hh.

    {
      using namespace JPP;
      
      in >> threshold;
 
      if (threshold < 0.0 || threshold > 1.0) {
        THROW(JValueOutOfRange, "JTestKolmogorov_1D::read(): Invalid threshold value " << threshold);
      }
      
      return in;
    }

write()

virtual std::ostream & JCOMPAREHISTOGRAMS::JTest_t::write ( std::ostream & out, const char delimiter = ' ', const bool onlyFailures = false ) const

inlinevirtualinherited

Write test result to output.

Parameters

out	output stream
delimiter	field delimiter
onlyFailures	if true, write only failures.

Returns

output stream

Definition at line 84 of file JTest_t.hh.

    {
      using namespace std;
      using namespace JPP;
 
      for (vector<JTestResult>::const_iterator r = this->begin() ; r != this->end() ; ++r) {
 
        if (onlyFailures && r->passed) { continue; }
        
        print(out, *r, delimiter, true);
      }
      
      return out;
    }

save()

virtual void JCOMPAREHISTOGRAMS::JTest_t::save ( TFile * f, const std::string & path, const bool onlyFailures = false ) const

inlinevirtualinherited

Writes the test result to root file.

Parameters

f	A ROOT file
path	Path in root file.
onlyFailures	If true, write only failures.

Definition at line 108 of file JTest_t.hh.

    {
      using namespace std;
      using namespace JPP;
 
      if (f->GetDirectory(path.c_str())==0) {
        f->mkdir(path.c_str());
      }
      
      f->cd(path.c_str());
 
      for (vector<JTestResult>::const_iterator r = this->begin() ; r != this->end() ; ++r) {
 
        if (onlyFailures && r->passed) { continue; }
        
        r->obj->Write();
      }
    }

getTestName()

const std::string & JCOMPAREHISTOGRAMS::JTest_t::getTestName ( ) const

inlineinherited

Get test name.

Returns

test name

Definition at line 135 of file JTest_t.hh.

    {
      return testName;
    }

getResultType()

const std::string & JCOMPAREHISTOGRAMS::JTest_t::getResultType ( ) const

inlineinherited

Get result type.

Returns

result type

Definition at line 146 of file JTest_t.hh.

    {
      return resultType;
    }

Member Data Documentation

threshold

double JCOMPAREHISTOGRAMS::JTestKolmogorov_1D::threshold

private

threshold p-value to decide if test is passed.

Definition at line 172 of file JTestKolmogorov_1D.hh.

testName

const std::string JCOMPAREHISTOGRAMS::JTest_t::testName

protectedinherited

test name

Definition at line 180 of file JTest_t.hh.

resultType

const std::string JCOMPAREHISTOGRAMS::JTest_t::resultType

protectedinherited

test result type

Definition at line 181 of file JTest_t.hh.

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The documentation for this class was generated from the following file:

• JTestKolmogorov_1D.hh