/**
* @param Neuron $neuron
*
* @return float
*/
public function getSigmaForNeuron(Neuron $neuron) : float
{
$sigma = 0.0;
foreach ($this->neuron->getSynapses() as $synapse) {
if ($synapse->getNode() == $neuron) {
$sigma += $synapse->getWeight() * $this->getSigma();
}
}
return $sigma;
}
public function testNeuronRefresh()
{
$neuron = new Neuron();
$neuron->getOutput();
$neuron->addSynapse($this->getSynapseMock());
$this->assertEquals(0.5, $neuron->getOutput(), '', 0.01);
$neuron->refresh();
$this->assertEquals(0.88, $neuron->getOutput(), '', 0.01);
}
/**
* @param Neuron $neuron
* @param array $target
* @param int $key
* @param bool $lastLayer
*
* @return float
*/
private function getSigma(Neuron $neuron, array $target, int $key, bool $lastLayer) : float
{
$neuronOutput = $neuron->getOutput();
$sigma = $neuronOutput * (1 - $neuronOutput);
if ($lastLayer) {
$sigma *= $target[$key] - $neuronOutput;
} else {
$sigma *= $this->getPrevSigma($neuron);
}
$this->sigmas[] = new Sigma($neuron, $sigma);
return $sigma;
}
/**
* @param Layer $currentLayer
* @param Neuron $nextNeuron
*/
private function generateNeuronSynapses(Layer $currentLayer, Neuron $nextNeuron)
{
foreach ($currentLayer->getNodes() as $currentNeuron) {
$nextNeuron->addSynapse(new Synapse($currentNeuron));
}
}
