JCOMPAREHISTOGRAMS::JTestZero Class Reference

Implementation of a bin-by-bin compatibility test for histograms with low bin contents. More...

#include <JTestZero.hh>

Inheritance diagram for JCOMPAREHISTOGRAMS::JTestZero:

Public Member Functions
	JTestZero ()
	Default constructor. More...
void	test (const TObject *o1, const TObject *o2) override
	Bin-by-bin comparison for ROOT histograms, of compatibility with a Poisson pdf of parameter 1. More...
std::istream &	read (std::istream &in) override
	Read test parameters from input. More...
virtual std::ostream &	write (std::ostream &out, const char delimiter= ' ', const bool onlyFailures=false) const
	Write test result to output. More...
virtual void	save (TFile *f, const std::string &path, const bool onlyFailures=false) const
	Writes the test result to root file. More...
const std::string &	getTestName () const
	Get test name. More...
const std::string &	getResultType () const
	Get result type. More...

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

Private Attributes
double	threshold
	threshold p-value to decide if test is passed. More...
double	outliersThreshold
	Fraction of bins allowed to fail. More...

Detailed Description

Implementation of a bin-by-bin compatibility test for histograms with low bin contents.

The test loops over all the bins of both histograms and performs the following operations.
-Calculates the probability that the observed bin content for histogram A is obtained from a Poisson of parameter 1.
-Compares the previous result with the threshold value given as an input parameter. The result is true if the probability is higher than the threshold.
-Calculates the probability that the observed bin content for histogram B is obtained from a Poisson of parameter 1.
-Compares the previous result with the threshold value given as an input parameter. The result is true if the probability is higher than the threshold.
-Compares the results from both bins: If both are true, or both are false, the test is passed. If one is true and the other is false, the test is failed.
At the end of the loop, a failure fraction is computed and compared to the outliersThreshold parameter. If the failure fraction is above the threshold, the test is failed.
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.

Definition at line 44 of file JTestZero.hh.

Constructor & Destructor Documentation

JCOMPAREHISTOGRAMS::JTestZero::JTestZero ( )

inline

Default constructor.

Definition at line 52 of file JTestZero.hh.

                :
      JTest_t("Zero", "failure_fraction")
    {}

Member Function Documentation

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

inlineoverridevirtual

Bin-by-bin comparison for ROOT histograms, of compatibility with a Poisson pdf of parameter 1.

Parameters

o1	First histogram
o2	Second histogram

Implements JCOMPAREHISTOGRAMS::JTest_t.

Definition at line 63 of file JTestZero.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 == NULL || h2 == NULL) {
        THROW(JValueOutOfRange, "JTestChi2::test(): Could not cast given TObjects to TH2.");
      }
    
      const int nx1 = h1->GetNbinsX();
      const int nx2 = h2->GetNbinsX();      
      const int ny1 = h1->GetNbinsY();
      const int ny2 = h2->GetNbinsY();
      const int nz1 = h1->GetNbinsZ();
      const int nz2 = h2->GetNbinsZ();

      if(nx1 != nx2 || ny1 != ny2 || nz1 != nz2) {
        THROW(JValueOutOfRange, "JTestZero::test(): Histograms with different binning. 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));
      
      h3->Reset();
      
      double failures = 0;
    
      for (int i=1 ; i<nx1+1 ; ++i) {
        for (int j=1 ; j<ny1+1 ; ++j) {
          for (int k=1 ; k<nz1+1 ; ++k) {

            const int Nbin = h3->GetBin(i,j,k);
        
            const double m = h1->GetBinContent(i,j,k);
            const double n = h2->GetBinContent(i,j,k);
        
            const double p1 = 1 - ROOT::Math::poisson_cdf(m,1);
            const double p2 = 1 - ROOT::Math::poisson_cdf(n,1);         

            if ((p1 > threshold && p2 < threshold) || 
                (p1 < threshold && p2 > threshold)) {
              
              failures+=1./(nx1*ny1);
              h3->Fill(Nbin);
            }
          }
        }
      }
      
      const bool passed = (failures < outliersThreshold);

      const JResultTitle title(testName, resultType, passed , failures);
      
      h3->SetTitle(title.getTitle().c_str());

      const int Ndims = h3->GetDimension();

      if        (Ndims == 1) {
        h3->GetYaxis()->SetTitle(resultType.c_str());
      } else if (Ndims == 2) {
        h3->GetZaxis()->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, failures, threshold, h3, passed);
      
      this->push_back(r);
    }

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

inlineoverridevirtual

Read test parameters from input.

Parameters

in	input stream

Returns

input stream

Implements JCOMPAREHISTOGRAMS::JTest_t.

Definition at line 146 of file JTestZero.hh.

    {
      using namespace JPP;

      in >> threshold >> outliersThreshold;

      if (threshold < 0.0 || threshold > 1.0) {
        THROW(JValueOutOfRange, "JTestZero::read(): Invalid threshold value " << threshold);    
      }

      if (outliersThreshold < 0.0 || outliersThreshold > 1.0) {
        THROW(JValueOutOfRange, "JTestZero::read(): Invalid outliersThreshold value " << outliersThreshold);
      }

      return in;
    }

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;
    }

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();
      }
    }

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;
    }

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

double JCOMPAREHISTOGRAMS::JTestZero::threshold

private

threshold p-value to decide if test is passed.

Definition at line 165 of file JTestZero.hh.

double JCOMPAREHISTOGRAMS::JTestZero::outliersThreshold

private

Fraction of bins allowed to fail.

Definition at line 166 of file JTestZero.hh.

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

protectedinherited

test name

Definition at line 180 of file JTest_t.hh.

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:

• JTestZero.hh