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See Release Notes

  • Bug fixes for general core bugs in 4.0.x will end 8 May 2023 (12 months).
  • Bug fixes for security issues in 4.0.x will end 13 November 2023 (18 months).
  • PHP version: minimum PHP 7.3.0 Note: the minimum PHP version has increased since Moodle 3.10. PHP 7.4.x is also supported.
<?php

declare(strict_types=1);

namespace Phpml\NeuralNetwork\Node;

use Phpml\NeuralNetwork\ActivationFunction;
use Phpml\NeuralNetwork\ActivationFunction\Sigmoid;
use Phpml\NeuralNetwork\Node;
use Phpml\NeuralNetwork\Node\Neuron\Synapse;

class Neuron implements Node
{
    /**
     * @var Synapse[]
     */
    protected $synapses = [];

    /**
     * @var ActivationFunction
     */
    protected $activationFunction;

    /**
     * @var float
     */
    protected $output = 0.0;

    /**
     * @var float
     */
    protected $z = 0.0;

    public function __construct(?ActivationFunction $activationFunction = null)
    {
< $this->activationFunction = $activationFunction ?: new Sigmoid();
> $this->activationFunction = $activationFunction ?? new Sigmoid();
} public function addSynapse(Synapse $synapse): void { $this->synapses[] = $synapse; } /** * @return Synapse[] */ public function getSynapses(): array { return $this->synapses; } public function getOutput(): float { if ($this->output === 0.0) { $this->z = 0; foreach ($this->synapses as $synapse) { $this->z += $synapse->getOutput(); } $this->output = $this->activationFunction->compute($this->z); } return $this->output; } public function getDerivative(): float { return $this->activationFunction->differentiate($this->z, $this->output); } public function reset(): void { $this->output = 0.0; $this->z = 0.0; } }