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TMVA::GiniIndexWithLaplace Class Reference

Implementation of the GiniIndex With Laplace correction as separation criterion.

Large Gini Indices (maximum 0.5) mean , that the sample is well mixed (same amount of signal and bkg) bkg.

Small Indices mean, well separated.

General definition:

\[ Gini(Sample M) = 1 - (\frac{c(1)}{N})^2 - (\frac{c(2)}{N})^2 .... - (\frac{c(k)}{N})^2 \]


\( M \) is a sample of whatever \( N \) elements (events) that belong to \( K \) different classes.

\( c(k) \) is the number of elements that belong to class \( k \) for just Signal and Background classes this boils down to:

The Laplace's correction to the probability distribution would turn the \( \frac{c(1)}{N} \) into \( \frac{(c(1)+1)}{(N+2)} \) using this the simple Gini Index for two classes

\[ Gini(Sample) = \frac{2sb}{(s+b)^2} \]

turns into

\[ GiniLaplace(Sample) = \frac{2(sb+s+b+1)}{(s+b+2)^2} \]

Definition at line 59 of file GiniIndexWithLaplace.h.

Public Member Functions

 GiniIndexWithLaplace ()
 GiniIndexWithLaplace (const GiniIndexWithLaplace &g)
virtual ~GiniIndexWithLaplace ()
virtual Double_t GetSeparationIndex (const Double_t s, const Double_t b)
virtual TClassIsA () const
virtual void Streamer (TBuffer &)
void StreamerNVirtual (TBuffer &ClassDef_StreamerNVirtual_b)
- Public Member Functions inherited from TMVA::SeparationBase
 SeparationBase ()
 SeparationBase (const SeparationBase &s)
 Copy constructor.
virtual ~SeparationBase ()
const TStringGetName ()
virtual Double_t GetSeparationGain (const Double_t nSelS, const Double_t nSelB, const Double_t nTotS, const Double_t nTotB)
 Separation Gain: the measure of how the quality of separation of the sample increases by splitting the sample e.g.
void StreamerNVirtual (TBuffer &ClassDef_StreamerNVirtual_b)

Static Public Member Functions

static TClassClass ()
static const char * Class_Name ()
static constexpr Version_t Class_Version ()
static const char * DeclFileName ()
- Static Public Member Functions inherited from TMVA::SeparationBase
static TClassClass ()
static const char * Class_Name ()
static constexpr Version_t Class_Version ()
static const char * DeclFileName ()

Additional Inherited Members

- Protected Attributes inherited from TMVA::SeparationBase
TString fName
Double_t fPrecisionCut

#include <TMVA/GiniIndexWithLaplace.h>

Inheritance diagram for TMVA::GiniIndexWithLaplace:

Constructor & Destructor Documentation

◆ GiniIndexWithLaplace() [1/2]

TMVA::GiniIndexWithLaplace::GiniIndexWithLaplace ( )

Definition at line 64 of file GiniIndexWithLaplace.h.

◆ GiniIndexWithLaplace() [2/2]

TMVA::GiniIndexWithLaplace::GiniIndexWithLaplace ( const GiniIndexWithLaplace g)

Definition at line 67 of file GiniIndexWithLaplace.h.

◆ ~GiniIndexWithLaplace()

virtual TMVA::GiniIndexWithLaplace::~GiniIndexWithLaplace ( )

Definition at line 70 of file GiniIndexWithLaplace.h.

Member Function Documentation

◆ Class()

static TClass * TMVA::GiniIndexWithLaplace::Class ( )
TClass describing this class

◆ Class_Name()

static const char * TMVA::GiniIndexWithLaplace::Class_Name ( )
Name of this class

◆ Class_Version()

static constexpr Version_t TMVA::GiniIndexWithLaplace::Class_Version ( )
Version of this class

Definition at line 77 of file GiniIndexWithLaplace.h.

◆ DeclFileName()

static const char * TMVA::GiniIndexWithLaplace::DeclFileName ( )
Name of the file containing the class declaration

Definition at line 77 of file GiniIndexWithLaplace.h.

◆ GetSeparationIndex()

Double_t TMVA::GiniIndexWithLaplace::GetSeparationIndex ( const Double_t  s,
const Double_t  b 

Implements TMVA::SeparationBase.

Definition at line 82 of file GiniIndexWithLaplace.cxx.

◆ IsA()

virtual TClass * TMVA::GiniIndexWithLaplace::IsA ( ) const
TClass describing current object

Reimplemented from TMVA::SeparationBase.

Definition at line 77 of file GiniIndexWithLaplace.h.

◆ Streamer()

virtual void TMVA::GiniIndexWithLaplace::Streamer ( TBuffer )

Reimplemented from TMVA::SeparationBase.

◆ StreamerNVirtual()

void TMVA::GiniIndexWithLaplace::StreamerNVirtual ( TBuffer ClassDef_StreamerNVirtual_b)

Definition at line 77 of file GiniIndexWithLaplace.h.

Libraries for TMVA::GiniIndexWithLaplace:

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