class TMVA::GiniIndex: public TMVA::SeparationBase
Implementation of the GiniIndex as separation criterion
Function Members (Methods)
public:
| virtual | ~GiniIndex() |
| static TClass* | Class() |
| const TString& | TMVA::SeparationBase::GetName() |
| virtual Double_t | TMVA::SeparationBase::GetSeparationGain(const Double_t& nSelS, const Double_t& nSelB, const Double_t& nTotS, const Double_t& nTotB) |
| virtual Double_t | GetSeparationIndex(const Double_t& s, const Double_t& b) |
| TMVA::GiniIndex | GiniIndex() |
| TMVA::GiniIndex | GiniIndex(const TMVA::GiniIndex& g) |
| virtual TClass* | IsA() const |
| TMVA::GiniIndex& | operator=(const TMVA::GiniIndex&) |
| virtual void | ShowMembers(TMemberInspector&) |
| virtual void | Streamer(TBuffer&) |
| void | StreamerNVirtual(TBuffer& ClassDef_StreamerNVirtual_b) |
Data Members
protected:
| TString | TMVA::SeparationBase::fName | name of the concrete Separation Index impementation |
| Double_t | TMVA::SeparationBase::fPrecisionCut |
Class Charts
Function documentation
Double_t GetSeparationIndex(const Double_t& s, const Double_t& b)
Gini(Sample M) = 1 - (c(1)/N)^2 - (c(2)/N)^2 .... - (c(k)/N)^2
Where: M is a smaple 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:
Gini(Sample) = 2s*b/(s+b)^2 ( = 2 * purity * (1-purity) )
!! what we use here is 2*Gini.. as for the later use the factor
2 is irrelevant and hence I'd like to save this calculation