Implementation of the Chi2 test for 2D histograms. More...

#include <JTestChi2_Slice2D.hh>

Inheritance diagram for JCOMPAREHISTOGRAMS::JTestChi2_Slice2D:

Public Member Functions
	JTestChi2_Slice2D ()
	Default constructor. More...

void	test (const TObject o1, const TObject o2) override
	Applies Chi2 test for two ROOT TH2 histograms. 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	failuresThreshold
	threshold p-value to decide if test is passed. More...

char	slice
	axis to slice. More...

std::string	options
	options for the ROOT chi2 test. More...

Detailed Description

Implementation of the Chi2 test for 2D 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.
The parameter slice() can have the values x, X, y or Y. The histograms are sliced along the corresponding axis, and the JChi2Test() test is applied to each slice.
The input parameter threshold, is used to evaluate whether the test is passed or failed for each slice.
The evaluation is done by comparing the threshold value with the result produced by the Chi2 test for each slice. The output of JChi2Test() is a p-value.
The parameter threshold should therefore be a real value between 0 and 1.

Definition at line 32 of file JTestChi2_Slice2D.hh.

Constructor & Destructor Documentation

◆ JTestChi2_Slice2D()

JCOMPAREHISTOGRAMS::JTestChi2_Slice2D::JTestChi2_Slice2D ( )

inline

Default constructor.

Definition at line 40 of file JTestChi2_Slice2D.hh.

                         :
       JTest_t("Chi2_Slice2D", "p-Value(chi2)")
     {}

Member Function Documentation

◆ test()

void JCOMPAREHISTOGRAMS::JTestChi2_Slice2D::test	(	const TObject *	o1,
		const TObject *	o2
	)

inlineoverridevirtual

Applies Chi2 test for two ROOT TH2 histograms.

Parameters

o1	First histogram
o2	Second histogram

Implements JCOMPAREHISTOGRAMS::JTest_t.

Definition at line 51 of file JTestChi2_Slice2D.hh.

     {
       using namespace std;
       using namespace JPP;
  
       const TH2* h1 = dynamic_cast<const TH2*>(o1);
       const TH2* h2 = dynamic_cast<const TH2*>(o2);
     
       if (h1 == NULL || h2 == NULL) {
         THROW(JValueOutOfRange, "JTestChi2_Slice2D::test(): Could not cast given TObjects to TH2");
       }
  
       TH1* h3 = NULL;
  
       const char* const h3name = (h1->GetName() == h2->GetName() ?
                                   MAKE_CSTRING(h1->GetName()                            << "_" << testName << "_" << slice) :
                                   MAKE_CSTRING(h1->GetName() << "_VS_" << h2->GetName() << "_" << testName << "_" << slice));
         
       int  nFailures = 0;
       int  nSlices   = 0;
     
       if (slice == 'x' || slice == 'X') {
     
         const int nSlices1 = h1->GetNbinsX();
         const int nSlices2 = h2->GetNbinsX();
  
         if (nSlices1 != nSlices2) {
           THROW(JValueOutOfRange, "JTestChi2_Slice2D::test(): Histograms with different binning. The objects: " << h1->GetName() << " and " << h2->GetName() << " can not be compared." << endl);
         }
  
         nSlices = nSlices1;
         
         h3 = h1->ProjectionX(h3name);
         
         for (int i=1 ; i<=nSlices1 ; ++i){
  
           const std::string sliceName = MAKE_STRING(h3->GetName() << "_" << to_string(i));
              
           const TH1* s1 = h1->ProjectionY(sliceName.c_str(),i,i);
           const TH1* s2 = h2->ProjectionY(sliceName.c_str(),i,i);
  
           if (!(s1->GetSumOfWeights() > 0 && s2->GetSumOfWeights() > 0)) { continue; }
  
           const double chi2 = s1->Chi2Test(s2 , options.c_str());
  
           const bool failed = (options.find("CHI2") != std::string::npos ?
                                (chi2 > threshold ? true : false) :
                                (chi2 < threshold ? true : false));
  
           if (failed) nFailures++;
         
           h3->SetBinContent(i,chi2); 
         }
             
       } else if (slice == 'y' || slice == 'Y') {
            
         const int nSlices1 = h1->GetNbinsY();
         const int nSlices2 = h2->GetNbinsY();
  
         if (nSlices1 != nSlices2) {
           THROW(JValueOutOfRange, "JTestChi2_Slice2D::test(): Histograms with different binning. The objects: " << h1->GetName() << " and " << h2->GetName() << " can not be compared." << endl);
         }
  
         nSlices = nSlices1;
  
         h3 = h1->ProjectionY(h3name);
  
         for (int i=1 ; i<=nSlices1 ; ++i){
              
           const std::string sliceName = MAKE_STRING(h3->GetName() << "_" << to_string(i));
  
           const TH1* s1 = h1->ProjectionX(sliceName.c_str(),i,i);
           const TH1* s2 = h2->ProjectionX(sliceName.c_str(),i,i);
  
           if (!(s1->GetSumOfWeights() > 0 && s2->GetSumOfWeights() > 0)) { continue; }    
  
           const double chi2 = s1->Chi2Test (s2 , options.c_str());
  
           const bool failed = (options.find("CHI2") != std::string::npos ?
                                (chi2 > threshold ? true : false) :
                                (chi2 < threshold ? true : false));;
  
           if (failed) nFailures++;
         
           h3->SetBinContent(i,chi2);
         }
       }
  
       const bool passed = (nFailures/nSlices < failuresThreshold);
  
       const JResultTitle title(testName, resultType, passed , nFailures);
       
       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, nFailures, failuresThreshold, h3, passed);
       
       this->push_back(r);
     }

◆ read()

std::istream& JCOMPAREHISTOGRAMS::JTestChi2_Slice2D::read ( std::istream & in )

inlineoverridevirtual

Read test parameters from input.

Parameters

in	input stream

Returns: input stream

Implements JCOMPAREHISTOGRAMS::JTest_t.

Definition at line 161 of file JTestChi2_Slice2D.hh.

     {
       using namespace JPP;
       
       in >> threshold >> failuresThreshold >> slice >> options;
  
       if (threshold < 0.0) {
         THROW(JValueOutOfRange, "JTestChi2_Slice2D::read(): Invalid threshold value " << threshold);    
       }
       
       if (failuresThreshold < 0.0 || failuresThreshold > 1.0) {
         THROW(JValueOutOfRange, "JTestChi2_Slice2D::read(): Invalid failuresThreshold value " << failuresThreshold);
       }
       
       if (slice != 'x' && slice != 'X' && slice != 'y' && slice != 'Y') {
         THROW(JValueOutOfRange, "JTestChi2_Slice2D::read(): Invalid slice option " << slice);
       }
  
       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::JTestChi2_Slice2D::threshold

private

threshold p-value to decide if test is passed.

Definition at line 185 of file JTestChi2_Slice2D.hh.

◆ failuresThreshold

double JCOMPAREHISTOGRAMS::JTestChi2_Slice2D::failuresThreshold

private

threshold p-value to decide if test is passed.

Definition at line 186 of file JTestChi2_Slice2D.hh.

◆ slice

char JCOMPAREHISTOGRAMS::JTestChi2_Slice2D::slice

private

axis to slice.

Definition at line 187 of file JTestChi2_Slice2D.hh.

◆ options

std::string JCOMPAREHISTOGRAMS::JTestChi2_Slice2D::options

private

options for the ROOT chi2 test.

Definition at line 188 of file JTestChi2_Slice2D.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.

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

JTestChi2_Slice2D.hh

Public Member Functions

Protected Attributes

Private Attributes

Detailed Description

Constructor & Destructor Documentation

◆ JTestChi2_Slice2D()

Member Function Documentation

◆ test()

◆ read()

◆ write()

◆ save()

◆ getTestName()

◆ getResultType()

Member Data Documentation

◆ threshold

◆ failuresThreshold

◆ slice

◆ options

◆ testName

◆ resultType