【ゼロから作るDeep Learning】2.5.2 XORゲートの実装（多層パーセプトロン）

2.5.2.php

<?php

//echo perceptron_xor(1, 1);

/**
 * Created by PhpStorm.
 * User: kure
 * Date: 11/14/17
 * Time: 1:37 PM
 */

/**
 * @param $type and or nand or or
 * @param $x1
 * @param $x2
 * @return int
 */
function perceptron(string $type, int $x1, int $x2){
    switch($type){
        case "and":
            $w1 = 0.5;
            $w2 = 0.5;
            $theta = 0.7;
            break;
        case "or":
            $w1 = 1;
            $w2 = 1;
            $theta = 0.5;
            break;
        case "nand":
            $w1 = -0.5;
            $w2 = -0.5;
            $theta = -0.7;
            break;
        default:
            echo "Error";
    }

    $w = $x1*$w1 + $x2*$w2;
    return($w > $theta) ?  1 : 0;
}

function perceptron_xor($x1, $x2){
    $s1 = perceptron("nand", $x1, $x2);
    $s2 = perceptron("or", $x1, $x2);
    return perceptron("and", $s1, $s2);
}