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Reference Guide
TActivationIdentity.h
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1 // @(#)root/tmva $Id$
2 // Author: Matt Jachowski
3 
4 /**********************************************************************************
5  * Project: TMVA - a Root-integrated toolkit for multivariate data analysis *
6  * Package: TMVA *
7  * Class : TMVA::TActivationIdentity *
8  * Web : http://tmva.sourceforge.net *
9  * *
10  * Description: *
11  * Identity activation function for TNeuron *
12  * *
13  * Authors (alphabetical): *
14  * Matt Jachowski <jachowski@stanford.edu> - Stanford University, USA *
15  * *
16  * Copyright (c) 2005: *
17  * CERN, Switzerland *
18  * *
19  * Redistribution and use in source and binary forms, with or without *
20  * modification, are permitted according to the terms listed in LICENSE *
21  * (http://tmva.sourceforge.net/LICENSE) *
22  **********************************************************************************/
23 
24 #ifndef ROOT_TMVA_TActivationIdentity
25 #define ROOT_TMVA_TActivationIdentity
26 
27 //////////////////////////////////////////////////////////////////////////
28 // //
29 // TActivationIdentity //
30 // //
31 // Identity activation function for TNeuron //
32 // //
33 //////////////////////////////////////////////////////////////////////////
34 
35 #include "TFormula.h"
36 #include "TString.h"
37 
38 #include "TMVA/TActivation.h"
39 
40 namespace TMVA {
41 
43 
44  public:
45 
48 
49  // evaluate the activation function
50  virtual Double_t Eval(Double_t arg) { return arg; } // f(x) = x
51 
52  // evaluate the derivative of the activation function
54  return 1; // f'(x) = 1
55  }
56 
57  // minimum of the range of the activation function
58  virtual Double_t GetMin() { return 0; } // these should never be called
59 
60  // maximum of the range of the activation function
61  virtual Double_t GetMax() { return 1; } // these should never be called
62 
63  // expression for activation function
64  virtual TString GetExpression() { return "x\t1"; }
65 
66  // writer of function code
67  virtual void MakeFunction(std::ostream& fout, const TString& fncName);
68 
69  private:
70 
71  ClassDef(TActivationIdentity,0); // Identity activation function for TNeuron
72  };
73 
74 } // namespace TMVA
75 
76 #endif
Basic string class.
Definition: TString.h:131
#define ClassDef(name, id)
Definition: Rtypes.h:320
virtual Double_t EvalDerivative(Double_t)
Identity activation function for TNeuron.
virtual TString GetExpression()
virtual void MakeFunction(std::ostream &fout, const TString &fncName)
writes the identity function source code
virtual Double_t Eval(Double_t arg)
double Double_t
Definition: RtypesCore.h:55
Abstract ClassifierFactory template that handles arbitrary types.
Interface for TNeuron activation function classes.
Definition: TActivation.h:42