An interface to calculate the "SeparationGain" for different separation criteria used in various training algorithms.

There are two things: the Separation Index, and the Separation Gain Separation Index: Measure of the "purity" of a sample. If all elements (events) in the sample belong to the same class (e.g. signal or background), than the separation index is 0 (meaning 100% purity (or 0% purity as it is symmetric. The index becomes maximal, for perfectly mixed samples eg. purity=50% , N_signal = N_bkg

Separation Gain: the measure of how the quality of separation of the sample increases by splitting the sample e.g. into a "left-node" and a "right-node" (N * Index_parent) - (N_left * Index_left) - (N_right * Index_right) this is then the quality criterion which is optimized for when trying to increase the information in the system (making the best selection

Definition at line 82 of file SeparationBase.h.

Public Member Functions
	SeparationBase ()
	Constructor.

	SeparationBase (const SeparationBase &s)
	Copy constructor.

virtual	~SeparationBase ()

const TString &	GetName ()

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.

virtual Double_t	GetSeparationIndex (const Double_t s, const Double_t b)=0

Protected Attributes
TString	fName

Double_t	fPrecisionCut

#include <TMVA/SeparationBase.h>

Inheritance diagram for TMVA::SeparationBase:

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Constructor & Destructor Documentation

◆ SeparationBase() [1/2]

TMVA::SeparationBase::SeparationBase ( )

Constructor.

Definition at line 76 of file SeparationBase.cxx.

◆ SeparationBase() [2/2]

TMVA::SeparationBase::SeparationBase ( const SeparationBase & s )

Copy constructor.

Definition at line 86 of file SeparationBase.cxx.

◆ ~SeparationBase()

virtual TMVA::SeparationBase::~SeparationBase ( )

inlinevirtual

Definition at line 93 of file SeparationBase.h.

Member Function Documentation

◆ GetName()

const TString & TMVA::SeparationBase::GetName ( )

inline

Definition at line 104 of file SeparationBase.h.

◆ GetSeparationGain()

Double_t TMVA::SeparationBase::GetSeparationGain	(	const Double_t	nSelS,
		const Double_t	nSelB,
		const Double_t	nTotS,
		const Double_t	nTotB
	)

virtual

Separation Gain: the measure of how the quality of separation of the sample increases by splitting the sample e.g.

into a "left-node" and a "right-node" (N * Index_parent) - (N_left * Index_left) - (N_right * Index_right) this is then the quality criterion which is optimized for when trying to increase the information in the system (making the best selection

Reimplemented in TMVA::SdivSqrtSplusB.

Definition at line 101 of file SeparationBase.cxx.

◆ GetSeparationIndex()

virtual Double_t TMVA::SeparationBase::GetSeparationIndex	(	const Double_t	s,
		const Double_t	b
	)

pure virtual

Implemented in TMVA::CrossEntropy, TMVA::GiniIndex, TMVA::GiniIndexWithLaplace, TMVA::MisClassificationError, and TMVA::SdivSqrtSplusB.

Member Data Documentation

◆ fName

TString TMVA::SeparationBase::fName

protected

Definition at line 108 of file SeparationBase.h.

◆ fPrecisionCut

Double_t TMVA::SeparationBase::fPrecisionCut