source: cpp/gdk/neuroimpl-simple.cpp @ 70

// This file is a part of the Framsticks GDK library.
// Copyright (C) 2002-2011  Szymon Ulatowski.  See LICENSE.txt for details.
// Refer to http://www.framsticks.com/ for further information.

#include "neuroimpl-simple.h"

#define NEURO_MAX 10.0
#define OVERLOAD 0.1
#define MUSCLESPEED   0.08
#define MUSCLEACC   0.01

int NI_StdNeuron::lateinit()
{
#ifdef MODEL_V1_COMPATIBLE
if (inertia<0) inertia=neuro->inertia;
if (force<0) force=neuro->force;
if (sigmo>1e9) sigmo=neuro->sigmo;
#endif
istate=newstate+neuro->state; // neuro->state -> random initialization
calcOutput();
neuro->state=newstate;
return 1;
}

void NI_StdNeuron::calcInternalState()
{
double sum=getWeightedInputSum();
velocity=force*(sum-istate)+inertia*velocity;
istate+=velocity;
if (istate>NEURO_MAX) istate=NEURO_MAX;
else if (istate<-NEURO_MAX) istate=-NEURO_MAX;
}

void NI_StdNeuron::go()
{
calcInternalState();
calcOutput();
}

void NI_StdNeuron::calcOutput()
{
double s=istate * sigmo;
if (s<-30.0) setState(-1);
else setState(2.0/(1.0+exp(-s))-1.0); // -1...1
}

void NI_StdUNeuron::calcOutput()
{
double s=istate * sigmo;
if (s<-30.0) setState(0);
else setState(1.0/(1.0+exp(-s))); // 0...1
}