|   | ROOT   6.16/01 Reference Guide | 
Calculate the "SeparationGain" for Regression analysis separation criteria 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 criteria which is optimized for when trying to increase the information in the system (making the best selection
Definition at line 66 of file RegressionVariance.h.
| Public Member Functions | |
| RegressionVariance () | |
| RegressionVariance (const RegressionVariance &s) | |
| virtual | ~RegressionVariance () | 
| TString | GetName () | 
| 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) | 
| Separation Gain: the measure of how the quality of separation of the sample increases by splitting the sample e.g.  More... | |
| virtual Double_t | GetSeparationIndex (const Double_t n, const Double_t target, const Double_t target2) | 
| Separation Index: a simple Variance.  More... | |
| Protected Attributes | |
| TString | fName | 
#include <TMVA/RegressionVariance.h>
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 | inline | 
Definition at line 71 of file RegressionVariance.h.
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 | inline | 
Definition at line 74 of file RegressionVariance.h.
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 | inlinevirtual | 
Definition at line 77 of file RegressionVariance.h.
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 | inline | 
Definition at line 88 of file RegressionVariance.h.
| Double_t TMVA::RegressionVariance::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 | ||
| ) | 
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 criteria which is optimized for when trying to increase the information in the system for the Regression: as the "Gain is maximised", the RMS (sqrt(variance)) which is used as a "separation" index should be as small as possible. the "figure of merit" here has to be -(rms left+rms-right) or 1/rms...
Definition at line 70 of file RegressionVariance.cxx.
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 | virtual | 
Separation Index: a simple Variance.
Definition at line 89 of file RegressionVariance.cxx.
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 | protected | 
Definition at line 92 of file RegressionVariance.h.