Phpml\NeuralNetwork\Training\Backpropagation::getPrevSigma PHP 메소드

    private function getPrevSigma(Neuron $neuron) : float
    {
        $sigma = 0.0;
        foreach ($this->sigmas as $neuronSigma) {
            $sigma += $neuronSigma->getSigmaForNeuron($neuron);
        }
        return $sigma;
    }