无意中发现php有个ml的库,不过需要php7以上才支持，看了下文档，简单整理下。

install php 7.1

brew install php-version
brew unlink php56
brew tap homebrew/dupes
brew tap homebrew/homebrew-php
brew install php71
php-version 7

php -v
PHP 7.1.10 (cli) (built: xx) ( NTS )
Copyright (c) 1997-2017 The PHP Group
Zend Engine v3.1.0, Copyright (c) 1998-2017 Zend Technologies

start php ml lib

下载依赖
composer require php-ai/php-ml  

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

use Phpml\Classification\KNearestNeighbors;

$samples = [[1, 3], [1, 4], [2, 4], [3, 1], [4, 1], [4, 2]];
$labels = ['a', 'a', 'a', 'b', 'b', 'b'];

$classifier = new KNearestNeighbors();
$classifier->train($samples, $labels);

echo $classifier->predict([3, 2]);

上面是KNN算法的例子，输出：
b

参考