A++ » TMVA » TMVA::RegressionVariance

class TMVA::RegressionVariance


RegressionVariance

Calculate the "SeparationGain" for Regression analysis
separation critiera used in various training algorithms

There are two things: the Separation Index, and the Separation Gain
Separation Index:
Measure of the "Variance" of a sample.

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 crition which is optimized for when trying
to increase the information in the system (making the best selection


Function Members (Methods)

public:
virtual~RegressionVariance()
static TClass*Class()
TStringGetName()
Double_tGetSeparationGain(const Double_t& nLeft, const Double_t& targetLeft, const Double_t& target2Left, const Double_t& nTot, const Double_t& targetTot, const Double_t& target2Tot)
virtual Double_tGetSeparationIndex(const Double_t& n, const Double_t& target, const Double_t& target2)
virtual TClass*IsA() const
TMVA::RegressionVariance&operator=(const TMVA::RegressionVariance&)
TMVA::RegressionVarianceRegressionVariance()
TMVA::RegressionVarianceRegressionVariance(const TMVA::RegressionVariance& s)
virtual voidShowMembers(TMemberInspector& insp) const
virtual voidStreamer(TBuffer&)
voidStreamerNVirtual(TBuffer& ClassDef_StreamerNVirtual_b)

Data Members

protected:
TStringfNamename of the concrete Separation Index impementation

Class Charts

Inheritance Chart:
TMVA::RegressionVariance

Function documentation

RegressionVariance()
default constructor
{fName = "Variance for Regression";}
RegressionVariance(const TMVA::RegressionVariance& s)
copy constructor
{}
virtual ~RegressionVariance()
 destructor
{}
Double_t GetSeparationGain(const Double_t& nLeft, const Double_t& targetLeft, const Double_t& target2Left, const Double_t& nTot, const Double_t& targetTot, const Double_t& target2Tot)
 Return the gain in separation of the original sample is splitted in two sub-samples
 (N * Index_parent) - (N_left * Index_left) - (N_right * Index_right)
TString GetName()
 Return the separation index (a measure for "purity" of the sample")
 Return the name of the concrete Index implementation
{ return fName; }