// @(#)root/tmva $Id: TActivationIdentity.h,v 1.6 2006/11/20 15:35:28 brun Exp $ // Author: Matt Jachowski /********************************************************************************** * Project: TMVA - a Root-integrated toolkit for multivariate data analysis * * Package: TMVA * * Class : TMVA::TActivationIdentity * * Web : http://tmva.sourceforge.net * * * * Description: * * Identity activation function for TNeuron * * * * Authors (alphabetical): * * Matt Jachowski <jachowski@stanford.edu> - Stanford University, USA * * * * Copyright (c) 2005: * * CERN, Switzerland * * * * Redistribution and use in source and binary forms, with or without * * modification, are permitted according to the terms listed in LICENSE * * (http://tmva.sourceforge.net/LICENSE) * **********************************************************************************/ #ifndef ROOT_TMVA_TActivationIdentity #define ROOT_TMVA_TActivationIdentity ////////////////////////////////////////////////////////////////////////// // // // TActivationIdentity // // // // Identity activation function for TNeuron // // // ////////////////////////////////////////////////////////////////////////// #include "TFormula.h" #include "TString.h" #ifndef ROOT_TMVA_TActivation #include "TMVA/TActivation.h" #endif namespace TMVA { class TActivationIdentity : public TActivation { public: TActivationIdentity() {} ~TActivationIdentity() {} // evaluate the activation function virtual Double_t Eval(Double_t arg) { return arg; } // f(x) = x // evaluate the derivative of the activation function virtual Double_t EvalDerivative(Double_t arg) { if (arg); return 1; // f'(x) = 1 } // minimum of the range of the activation function virtual Double_t GetMin() { return 0; } // these should never be called // maximum of the range of the activation function virtual Double_t GetMax() { return 1; } // these should never be called // expression for activation function virtual TString GetExpression() { return "x\t1"; } private: ClassDef(TActivationIdentity,0) // Identity activation function for TNeuron ; }; } // namespace TMVA #endif