JTestZero Class Reference

Implementation of a bin-by-bin compatibility test for 2D histograms with low bin contents. More...

#include <JTestZero.hh>

Inheritance diagram for JTestZero:

Public Member Functions
	JTestZero ()
	Default constructor. More...
std::istream &	read (std::istream &in) override
	Read test parameters from input. More...
std::ostream &	write (std::ostream &out, std::string delimiter=" ", bool onlyFailures=false) const override
	Write test result to output. More...
void	test (TObject *o1, TObject *o2) override
	Bin-by-bin comparison for ROOT TH2 histograms, of compatibility with a Poisson pdf of parameter 1. More...
virtual void	save (TFile *f, std::string path, bool onlyFailures=false) override
	Writes the test result to root file. More...
void	clear () override
	Clear results. More...
std::string	getName () override
	Get test name. More...
std::string	getParameter () override
	Get parameter name. More...
JTestResult	JTestZero_2D (TH2 *h1, TH2 *h2, double outliersThreshold, double threshold, std::string testName, std::string parameterName)
	Bin-by-Bin test for 2D histograms where a very low number of entries is expected. More...

Public Attributes
std::vector< JTestResult >	results

Private Attributes
double	outliersThreshold
	Fraction of bins allowed to fail. More...
double	threshold
	threshold p-value to decide if test is passed. More...
const std::string	name = "Zero"
	test name. More...
const std::string	parameter = "failure_fraction"
	parameter name. More...

Detailed Description

Implementation of a bin-by-bin compatibility test for 2D histograms with low bin contents.

Author

rgruiz
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.
The test is run by the method JTestZero_2D().

Definition at line 27 of file JTestZero.hh.

Constructor & Destructor Documentation

JTestZero::JTestZero ( )

inline

Default constructor.

Definition at line 36 of file JTestZero.hh.

{}

Member Function Documentation

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

inlineoverridevirtual

Read test parameters from input.

Parameters

in	input stream

Returns

input stream

Implements JTest_t.

Definition at line 44 of file JTestZero.hh.

                                           { 
    return in >> outliersThreshold >> threshold;
  };

std::ostream& JTestZero::write ( std::ostream &  out, std::string  delimiter = " ", bool  onlyFailures = false  ) const

inlineoverridevirtual

Write test result to output.

Parameters

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

Returns

output stream

Implements JTest_t.

Definition at line 56 of file JTestZero.hh.

                                                                                                         {
    for (std::vector<JTestResult>::const_iterator r = results.begin() ; r != results.end() ; ++r) {
      if (onlyFailures){
        if (!r->passed)
          out << std::scientific << std::setprecision(2) << (r->passed ? JPP::GREEN : JPP::RED) << r->print(delimiter) << std::endl;
      }else{
        out << std::scientific << std::setprecision(2) << (r->passed ? JPP::GREEN : JPP::RED) << r->print(delimiter) << std::endl;
      }
    }
    return out;
  };

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

inlineoverridevirtual

Bin-by-bin comparison for ROOT TH2 histograms, of compatibility with a Poisson pdf of parameter 1.

Parameters

o1	First histogram
o2	Second histogram

Implements JTest_t.

Definition at line 74 of file JTestZero.hh.

                                              {    

    using namespace std;
    
    if (!(dynamic_cast<TH2*>(o1) == NULL) && !(dynamic_cast<TH2*>(o2) == NULL)) {
                  
      TH2D* h1 = dynamic_cast<TH2D*>(o1);
      TH2D* h2 = dynamic_cast<TH2D*>(o2);
      
      JTestResult r = JTestZero_2D(h1, h2, outliersThreshold, threshold, name, parameter);
      results.push_back(r);
    }
  };

virtual void JTestZero::save ( TFile *  f, std::string  path, bool  onlyFailures = false  )

inlineoverridevirtual

Writes the test result to root file.

Parameters

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

Implements JTest_t.

Definition at line 94 of file JTestZero.hh.

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

void JTestZero::clear ( )

inlineoverridevirtual

Clear results.

Implements JTest_t.

Definition at line 117 of file JTestZero.hh.

                       {
    results.clear();
  }

std::string JTestZero::getName ( )

inlineoverridevirtual

Get test name.

Implements JTest_t.

Definition at line 124 of file JTestZero.hh.

                              {
    return name;
  }

std::string JTestZero::getParameter ( )

inlineoverridevirtual

Get parameter name.

Implements JTest_t.

Definition at line 131 of file JTestZero.hh.

                                   {
    return parameter;
  }

JTestResult JTestZero_t::JTestZero_2D ( TH2 *  h1, TH2 *  h2, double  outliersThreshold, double  threshold, std::string  testName, std::string  parameterName  )

inlineinherited

Bin-by-Bin test for 2D histograms where a very low number of entries is expected.

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.

Parameters

h1	First object
h2	Second object
outliersThreshold	Fraction of incompatible bins allowed.
threshold	Poisson p-value
parameterName	Name of the parameter used to test the histograms
testName	Name of the test used to compare the histograms

Definition at line 46 of file JTestZero_t.hh.

                                                                                                                                      {    

    using namespace std;
    using namespace JPP;
    
    int nx1 = h1->GetNbinsX();
    int nx2 = h2->GetNbinsX();      
    int ny1 = h1->GetNbinsY();
    int ny2 = h2->GetNbinsY();

    if(nx1 != nx2 || ny1 != ny2)
      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();

    double failures = 0;
    
    for (int i=1 ; i<nx1+1 ; ++i){
      for (int j=1 ; j<ny1+1 ; ++j){
        
        double m = h1 -> GetBinContent(i,j);
        double n = h2 -> GetBinContent(i,j);
        
        double p1 = 1 - ROOT::Math::poisson_cdf(m,1);
        double p2 = 1 - ROOT::Math::poisson_cdf(n,1);   

        if ((p1 > threshold && p2 < threshold) || 
            (p1 < threshold && p2 > threshold)){
          h3->Fill(i,j);
          failures+=1./(nx1*ny1);
        }        
      }
    }

    bool passed;
    
    (failures > outliersThreshold ? passed = false : passed = true);
    
    JResultTitle title(testName, parameterName, passed , failures);
    
    h3->SetTitle(title.getTitle().c_str());
    
    JTestResult r (testName,
                   string (h1->GetDirectory()->GetPath()).append(h1->GetName()),
                   string (h2->GetDirectory()->GetPath()).append(h2->GetName()),
                   h1->GetDirectory()->GetFile()->GetName(),
                   h2->GetDirectory()->GetFile()->GetName(),
                   parameterName, failures, threshold, h3, passed);

    return r;      
  };

Member Data Documentation

double JTestZero::outliersThreshold

private

Fraction of bins allowed to fail.

Definition at line 136 of file JTestZero.hh.

double JTestZero::threshold

private

threshold p-value to decide if test is passed.

Definition at line 137 of file JTestZero.hh.

const std::string JTestZero::name = "Zero"

private

test name.

Definition at line 138 of file JTestZero.hh.

const std::string JTestZero::parameter = "failure_fraction"

private

parameter name.

Definition at line 139 of file JTestZero.hh.

std::vector<JTestResult> JTest_t::results

inherited

Buffer to store results of multiple tests.

Definition at line 251 of file JTest_t.hh.

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

• JTestZero.hh