#include "brain/neuron.h"
#include <cmath>

double Neuron::sigmoid(double input) const
{
    double slope = 4.924273;
    return (1/(1+(std::exp(-(slope*input)))));
}

void Neuron::calculateActivation()
{
    double newActivation = 0;
    for (auto const& link : _inputLinks)
    {
	newActivation += link->weightedActivation();
    }
    newActivation = sigmoid(newActivation);

    _activationChanged = newActivation != _activation;
    _activation = newActivation;
}

void Neuron::addInput(std::unique_ptr<NeuralLink>&& link)
{
    _inputLinks.push_back(std::move(link));
}