#include <neuron.h>

Public Types
enum	NeuronTypes { Unknown = 0, Input, Hidden, Output }
Public Member Functions
	Neuron ()
	~Neuron ()
void	Clear ()
template<class BuffType >
bool	ReadBinary (BuffType *input_buff)
void	AddFromConnection (Neuron neuron_vec, float wts_offset, int from_cnt)
void	set_node_type (NeuronTypes type)
void	FeedForward ()
float	output () const
void	set_output (float out_val)
int	id () const
int	fan_in_cnt () const
Neuron *	fan_in (int idx) const
float	fan_in_wts (int idx) const
void	set_id (int id)
float	bias () const
Neuron::NeuronTypes	node_type () const
Static Public Member Functions
static float	Sigmoid (float activation)
Protected Member Functions
void	Init ()
Protected Attributes
NeuronTypes	node_type_
int	id_
float	bias_
float	activation_
float	output_
vector< Neuron * >	fan_in_
vector< float * >	fan_in_weights_
bool	frwd_dirty_
Static Protected Attributes
static const float	kSigmoidTable []

Detailed Description

Definition at line 24 of file neuron.h.

Member Enumeration Documentation

enum tesseract::Neuron::NeuronTypes

Enumerator:

Unknown
Input
Hidden
Output

Definition at line 27 of file neuron.h.

                     {
      Unknown = 0,
      Input,
      Hidden,
      Output
    };

Constructor & Destructor Documentation

tesseract::Neuron::Neuron ( )

Definition at line 17 of file neuron.cpp.

               {
  Init();
}

tesseract::Neuron::~Neuron ( )

Definition at line 22 of file neuron.cpp.

{
}

Member Function Documentation

void tesseract::Neuron::AddFromConnection	(	Neuron *	neuron_vec,
		float *	wts_offset,
		int	from_cnt
	)

Definition at line 74 of file neuron.cpp.

                                             {
  for (int in = 0; in < from_cnt; in++) {
    fan_in_.push_back(neurons + in);
    fan_in_weights_.push_back(wts_offset + in);
  }
}

float tesseract::Neuron::bias ( ) const [inline]

Definition at line 114 of file neuron.h.

                       {
      return bias_;
    }

void tesseract::Neuron::Clear ( ) [inline]

Definition at line 37 of file neuron.h.

                 {
      frwd_dirty_  =  true;
    }

Neuron* tesseract::Neuron::fan_in ( int idx ) const [inline]

Definition at line 105 of file neuron.h.

                                   {
      return fan_in_[idx];
    }

int tesseract::Neuron::fan_in_cnt ( ) const [inline]

Definition at line 102 of file neuron.h.

                           {
      return fan_in_.size();
    }

float tesseract::Neuron::fan_in_wts ( int idx ) const [inline]

Definition at line 108 of file neuron.h.

                                    {
      return *(fan_in_weights_[idx]);
    }

void tesseract::Neuron::FeedForward ( )

Definition at line 39 of file neuron.cpp.

                         {
  if (!frwd_dirty_ ) {
    return;
  }
  // nothing to do for input nodes: just pass the input to the o/p
  // otherwise, pull the output of all fan-in neurons
  if (node_type_ != Input) {
    int fan_in_cnt = fan_in_.size();
    // sum out the activation
    activation_ = -bias_;
    for (int in = 0; in < fan_in_cnt; in++) {
      if (fan_in_[in]->frwd_dirty_) {
        fan_in_[in]->FeedForward();
      }
      activation_ += ((*(fan_in_weights_[in])) * fan_in_[in]->output_);
    }
    // sigmoid it
    output_ = Sigmoid(activation_);
  }
  frwd_dirty_ = false;
}

int tesseract::Neuron::id ( ) const [inline]

Definition at line 99 of file neuron.h.

                   {
      return id_;
    }

void tesseract::Neuron::Init ( ) [protected]

Definition at line 26 of file neuron.cpp.

                  {
  id_ = -1;
  frwd_dirty_ = false;
  fan_in_.clear();
  fan_in_weights_.clear();
  activation_ = 0.0f;
  output_ = 0.0f;
  bias_ = 0.0f;
  node_type_ = Unknown;
}

Neuron::NeuronTypes tesseract::Neuron::node_type ( ) const [inline]

Definition at line 117 of file neuron.h.

                                        {
      return node_type_;
    }

float tesseract::Neuron::output ( ) const [inline]

Definition at line 93 of file neuron.h.

                         {
      return output_;
    }

template<class BuffType >

template bool tesseract::Neuron::ReadBinary ( BuffType * input_buff ) [inline]

Definition at line 42 of file neuron.h.

                                                                    {
      float val;
      if (input_buff->Read(&val, sizeof(val)) != sizeof(val)) {
        return false;
      }
      // input nodes should have no biases
      if (node_type_ == Input) {
        bias_ = kInputNodeBias;
      } else {
        bias_ = val;
      }
      // read fanin count
      int fan_in_cnt;
      if (input_buff->Read(&fan_in_cnt, sizeof(fan_in_cnt)) !=
          sizeof(fan_in_cnt)) {
        return false;
      }
      // validate fan-in cnt
      if (fan_in_cnt != fan_in_.size()) {
        return false;
      }
      // read the weights
      for (int in = 0; in < fan_in_cnt; in++) {
        if (input_buff->Read(&val, sizeof(val)) != sizeof(val)) {
          return false;
        }
        *(fan_in_weights_[in]) = val;
      }
      return true;
    }

void tesseract::Neuron::set_id ( int id ) [inline]

Definition at line 111 of file neuron.h.

                        {
      id_ = id;
    }

void tesseract::Neuron::set_node_type ( NeuronTypes type )

Definition at line 62 of file neuron.cpp.

                                           {
  node_type_ = Type;
}

void tesseract::Neuron::set_output ( float out_val ) [inline]

Definition at line 96 of file neuron.h.

                                   {
      output_ = out_val;
    }

float tesseract::Neuron::Sigmoid ( float activation ) [static]

Definition at line 85 of file neuron.cpp.

                                      {
  if (activation <= -10.0f) {
    return 0.0f;
  } else if (activation >= 10.0f) {
    return 1.0f;
  } else {
    return kSigmoidTable[static_cast<int>(100 * (activation + 10.0))];
  }
}