PHP code example of a1essandro / neural-network

    
        
<?php
require_once('vendor/autoload.php');

/* Start to develop here. Best regards https://php-download.com/ */

    

a1essandro / neural-network example snippets

use Neural\BackpropagationTeacher;
use Neural\MultilayerPerceptron;

ith 2 neurons and one output neuron:
$p = new MultilayerPerceptron([2, 2, 1]); //You may add more hidden layers or neurons to layers: [2, 3, 2, 1]
$p->generateSynapses(); //automatically add synapses

$t = new BackpropagationTeacher($p); //Teacher with backpropagation algorithm

//Teach until it learns
$learningResult = $t->teachKit(
    [[1, 0], [0, 1], [1, 1], [0, 0]], //kit for learning
    [[1], [1], [0], [0]], //appropriate expectations 
    0.3, //error
    10000 //max iterations
);

if ($learningResult != -1) {
    echo '1,0: ' . round($p->input([1, 0])->output()[0]) . PHP_EOL;
    echo '0,1: ' . round($p->input([0, 1])->output()[0]) . PHP_EOL;
    echo '0,0: ' . round($p->input([0, 0])->output()[0]) . PHP_EOL;
    echo '1,1: ' . round($p->input([1, 1])->output()[0]) . PHP_EOL;
}

/* Result:
1,0: 1
0,1: 1
0,0: 0
1,1: 0
*/

$p = new MultilayerPerceptron([2, 2, 1]);

//Equivalent to:

$p = new MultilayerPerceptron();
$p->addLayer(new Layer())->toLastLayer()
    ->addNode(new Input())
    ->addNode(new Input())
    ->addNode(new Bias());
$p->addLayer(new Layer())->toLastLayer()
    ->addNode(new Neuron())
    ->addNode(new Neuron())
    ->addNode(new Bias());
$p->addLayer(new Layer())->toLastLayer()
    ->addNode(new Neuron());

//Do not forget to add synapses:

$p->generateSynapses();

//Or you may direct the process:

$neuronFilter = function($node) {
    return $node instanceof Neuron;
};

$secondLayerNeuron = iterator_to_array($p->getLayers()[1]->getNodes($neuronFilter))[0];
$input = iterator_to_array($p->getLayers()[0]->getNodes())[0];
$secondLayerNeuron->addSynapse(new Synapse($input));

//and so on...