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TNeuron Class Reference

Definition at line 44 of file TNeuron.h.

Public Types

enum  ENeuronType {
  kOff, kLinear, kSigmoid, kTanh,
  kGauss, kSoftmax, kExternal
}
 

Public Member Functions

 TNeuron (ENeuronType type=kSigmoid, const char *name="", const char *title="", const char *extF="", const char *extD="")
 Usual constructor. More...
 
virtual ~TNeuron ()
 
void AddInLayer (TNeuron *)
 Tells a neuron which neurons form its layer (including itself). More...
 
void ForceExternalValue (Double_t value)
 Uses the branch type to force an external value. More...
 
Double_t GetBranch () const
 Returns the formula value. More...
 
Double_t GetDeDw () const
 Computes the derivative of the error wrt the neuron weight. More...
 
Double_t GetDEDw () const
 
Double_t GetDerivative () const
 computes the derivative for the appropriate function at the working point More...
 
Double_t GetError () const
 Computes the error for output neurons. More...
 
TNeuronGetInLayer (Int_t n) const
 
Double_t GetInput () const
 Returns neuron input. More...
 
const Double_t * GetNormalisation () const
 
TSynapseGetPost (Int_t n) const
 
TSynapseGetPre (Int_t n) const
 
Double_t GetTarget () const
 Computes the normalized target pattern for output neurons. More...
 
ENeuronType GetType () const
 Returns the neuron type. More...
 
Double_t GetValue () const
 Computes the output using the appropriate function and all the weighted inputs, or uses the branch as input. More...
 
Double_t GetWeight () const
 
void SetDEDw (Double_t in)
 Sets the derivative of the total error wrt the neuron weight. More...
 
void SetNewEvent () const
 Inform the neuron that inputs of the network have changed, so that the buffered values have to be recomputed. More...
 
void SetNormalisation (Double_t mean, Double_t RMS)
 Sets the normalization variables. More...
 
void SetWeight (Double_t w)
 Sets the neuron weight to w. More...
 
TTreeFormula * UseBranch (TTree *, const char *)
 Sets a formula that can be used to make the neuron an input. More...
 

Protected Member Functions

void AddPost (TSynapse *)
 Adds a synapse to the neuron as an output This method is used by the TSynapse while connecting two neurons. More...
 
void AddPre (TSynapse *)
 Adds a synapse to the neuron as an input This method is used by the TSynapse while connecting two neurons. More...
 
Double_t DSigmoid (Double_t x) const
 The Derivative of the Sigmoid. More...
 
Double_t Sigmoid (Double_t x) const
 The Sigmoid. More...
 

Private Member Functions

 TNeuron (const TNeuron &)
 
TNeuronoperator= (const TNeuron &)
 

Private Attributes

Double_t fDeDw
 do we need to compute fDeDw again ? More...
 
Double_t fDEDw
 buffer containing the last derivative of the error More...
 
Double_t fDerivative
 do we need to compute fDerivative again ? More...
 
TFormula * fExtD
 
TFormula * fExtF
 
TTreeFormula * fFormula
 
Int_t fIndex
 formula to be used for inputs and outputs More...
 
Double_t fInput
 do we need to compute fInput again ? More...
 
TObjArray flayer
 
Bool_t fNewDeDw
 buffer containing the last neuron derivative More...
 
Bool_t fNewDeriv
 buffer containing the last neuron output More...
 
Bool_t fNewInput
 index in the formula More...
 
Bool_t fNewValue
 buffer containing the last neuron input More...
 
Double_t fNorm [2]
 
TObjArray fpost
 
TObjArray fpre
 
ENeuronType fType
 
Double_t fValue
 do we need to compute fValue again ? More...
 
Double_t fWeight
 

Friends

class TSynapse
 

#include <TNeuron.h>

Inheritance diagram for TNeuron:
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Member Enumeration Documentation

◆ ENeuronType

Enumerator
kOff 
kLinear 
kSigmoid 
kTanh 
kGauss 
kSoftmax 
kExternal 

Definition at line 48 of file TNeuron.h.

Constructor & Destructor Documentation

◆ TNeuron() [1/2]

TNeuron::TNeuron ( TNeuron::ENeuronType  type = kSigmoid,
const char *  name = "",
const char *  title = "",
const char *  extF = "",
const char *  extD = "" 
)

Usual constructor.

Definition at line 51 of file TNeuron.cxx.

◆ ~TNeuron()

virtual TNeuron::~TNeuron ( )
inlinevirtual

Definition at line 53 of file TNeuron.h.

◆ TNeuron() [2/2]

TNeuron::TNeuron ( const TNeuron )
private

Member Function Documentation

◆ AddInLayer()

void TNeuron::AddInLayer ( TNeuron nearP)

Tells a neuron which neurons form its layer (including itself).

This is needed for self-normalizing functions, like Softmax.

Definition at line 857 of file TNeuron.cxx.

◆ AddPost()

void TNeuron::AddPost ( TSynapse post)
protected

Adds a synapse to the neuron as an output This method is used by the TSynapse while connecting two neurons.

Definition at line 846 of file TNeuron.cxx.

◆ AddPre()

void TNeuron::AddPre ( TSynapse pre)
protected

Adds a synapse to the neuron as an input This method is used by the TSynapse while connecting two neurons.

Definition at line 834 of file TNeuron.cxx.

◆ DSigmoid()

Double_t TNeuron::DSigmoid ( Double_t  x) const
protected

The Derivative of the Sigmoid.

Definition at line 818 of file TNeuron.cxx.

◆ ForceExternalValue()

void TNeuron::ForceExternalValue ( Double_t  value)

Uses the branch type to force an external value.

Definition at line 1125 of file TNeuron.cxx.

◆ GetBranch()

Double_t TNeuron::GetBranch ( ) const

Returns the formula value.

Definition at line 914 of file TNeuron.cxx.

◆ GetDeDw()

Double_t TNeuron::GetDeDw ( ) const

Computes the derivative of the error wrt the neuron weight.

Definition at line 1084 of file TNeuron.cxx.

◆ GetDEDw()

Double_t TNeuron::GetDEDw ( ) const
inline

Definition at line 72 of file TNeuron.h.

◆ GetDerivative()

Double_t TNeuron::GetDerivative ( ) const

computes the derivative for the appropriate function at the working point

Definition at line 1011 of file TNeuron.cxx.

◆ GetError()

Double_t TNeuron::GetError ( ) const

Computes the error for output neurons.

Returns 0 for other neurons.

Definition at line 1063 of file TNeuron.cxx.

◆ GetInLayer()

TNeuron* TNeuron::GetInLayer ( Int_t  n) const
inline

Definition at line 56 of file TNeuron.h.

◆ GetInput()

Double_t TNeuron::GetInput ( ) const

Returns neuron input.

Definition at line 925 of file TNeuron.cxx.

◆ GetNormalisation()

const Double_t* TNeuron::GetNormalisation ( ) const
inline

Definition at line 69 of file TNeuron.h.

◆ GetPost()

TSynapse* TNeuron::GetPost ( Int_t  n) const
inline

Definition at line 55 of file TNeuron.h.

◆ GetPre()

TSynapse* TNeuron::GetPre ( Int_t  n) const
inline

Definition at line 54 of file TNeuron.h.

◆ GetTarget()

Double_t TNeuron::GetTarget ( ) const

Computes the normalized target pattern for output neurons.

Returns 0 for other neurons.

Definition at line 1074 of file TNeuron.cxx.

◆ GetType()

TNeuron::ENeuronType TNeuron::GetType ( ) const

Returns the neuron type.

Definition at line 867 of file TNeuron.cxx.

◆ GetValue()

Double_t TNeuron::GetValue ( ) const

Computes the output using the appropriate function and all the weighted inputs, or uses the branch as input.

In that case, the branch normalisation is also used.

Definition at line 948 of file TNeuron.cxx.

◆ GetWeight()

Double_t TNeuron::GetWeight ( ) const
inline

Definition at line 67 of file TNeuron.h.

◆ operator=()

TNeuron& TNeuron::operator= ( const TNeuron )
private

◆ SetDEDw()

void TNeuron::SetDEDw ( Double_t  in)

Sets the derivative of the total error wrt the neuron weight.

Definition at line 1168 of file TNeuron.cxx.

◆ SetNewEvent()

void TNeuron::SetNewEvent ( ) const

Inform the neuron that inputs of the network have changed, so that the buffered values have to be recomputed.

Definition at line 1157 of file TNeuron.cxx.

◆ SetNormalisation()

void TNeuron::SetNormalisation ( Double_t  mean,
Double_t  RMS 
)

Sets the normalization variables.

Any input neuron will return (branch-mean)/RMS. When UseBranch is called, mean and RMS are automatically set to the actual branch mean and RMS.

Definition at line 1137 of file TNeuron.cxx.

◆ SetWeight()

void TNeuron::SetWeight ( Double_t  w)

Sets the neuron weight to w.

The neuron weight corresponds to the bias in the linear combination of the inputs.

Definition at line 1148 of file TNeuron.cxx.

◆ Sigmoid()

Double_t TNeuron::Sigmoid ( Double_t  x) const
protected

The Sigmoid.

Fast computation of the values of the sigmoid function. Uses values of the function up to the seventh order tabulated at 700 points. Values were computed in long double precision (16 bytes, precision to about 37 digits) on a hp computer. Some values were checked with Mathematica. Result should be correct to ~ 15 digits (about double precision)

From the mlpfit package (J.Schwindling 20-Jul-1999)

Definition at line 95 of file TNeuron.cxx.

◆ UseBranch()

TTreeFormula * TNeuron::UseBranch ( TTree *  input,
const char *  formula 
)

Sets a formula that can be used to make the neuron an input.

The formula is automatically normalized to mean=0, RMS=1. This normalisation is used by GetValue() (input neurons) and GetError() (output neurons)

Definition at line 878 of file TNeuron.cxx.

Friends And Related Function Documentation

◆ TSynapse

friend class TSynapse
friend

Definition at line 45 of file TNeuron.h.

Member Data Documentation

◆ fDeDw

Double_t TNeuron::fDeDw
private

do we need to compute fDeDw again ?

Definition at line 105 of file TNeuron.h.

◆ fDEDw

Double_t TNeuron::fDEDw
private

buffer containing the last derivative of the error

Definition at line 106 of file TNeuron.h.

◆ fDerivative

Double_t TNeuron::fDerivative
private

do we need to compute fDerivative again ?

Definition at line 103 of file TNeuron.h.

◆ fExtD

TFormula* TNeuron::fExtD
private

Definition at line 93 of file TNeuron.h.

◆ fExtF

TFormula* TNeuron::fExtF
private

Definition at line 92 of file TNeuron.h.

◆ fFormula

TTreeFormula* TNeuron::fFormula
private

Definition at line 96 of file TNeuron.h.

◆ fIndex

Int_t TNeuron::fIndex
private

formula to be used for inputs and outputs

Definition at line 97 of file TNeuron.h.

◆ fInput

Double_t TNeuron::fInput
private

do we need to compute fInput again ?

Definition at line 99 of file TNeuron.h.

◆ flayer

TObjArray TNeuron::flayer
private

Definition at line 88 of file TNeuron.h.

◆ fNewDeDw

Bool_t TNeuron::fNewDeDw
private

buffer containing the last neuron derivative

Definition at line 104 of file TNeuron.h.

◆ fNewDeriv

Bool_t TNeuron::fNewDeriv
private

buffer containing the last neuron output

Definition at line 102 of file TNeuron.h.

◆ fNewInput

Bool_t TNeuron::fNewInput
private

index in the formula

Definition at line 98 of file TNeuron.h.

◆ fNewValue

Bool_t TNeuron::fNewValue
private

buffer containing the last neuron input

Definition at line 100 of file TNeuron.h.

◆ fNorm

Double_t TNeuron::fNorm[2]
private

Definition at line 90 of file TNeuron.h.

◆ fpost

TObjArray TNeuron::fpost
private

Definition at line 87 of file TNeuron.h.

◆ fpre

TObjArray TNeuron::fpre
private

Definition at line 86 of file TNeuron.h.

◆ fType

ENeuronType TNeuron::fType
private

Definition at line 91 of file TNeuron.h.

◆ fValue

Double_t TNeuron::fValue
private

do we need to compute fValue again ?

Definition at line 101 of file TNeuron.h.

◆ fWeight

Double_t TNeuron::fWeight
private

Definition at line 89 of file TNeuron.h.

Libraries for TNeuron:
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The documentation for this class was generated from the following files: