Implementation of the GiniIndexWithLaplace as separation criterion
TString | TMVA::SeparationBase::fName | name of the concrete Separation Index impementation |
Double_t | TMVA::SeparationBase::fPrecisionCut |
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 Laplace's correction to the prob.density c/N --> (c+1)/(N+2) for just Signal and Background classes this then boils down to: Gini(Sample) = 2(s*b+s+b+1)/(s+b+2)^2