Code Coverage for /var/www/php-ml/src/Phpml/Preprocessing/Normalizer.php

1	<?php
2
3	declare (strict_types = 1);
4
5	namespace Phpml\Preprocessing;
6
7	use Phpml\Exception\NormalizerException;
8
9	class Normalizer implements Preprocessor
10	{
11	const NORM_L1 = 1;
12	const NORM_L2 = 2;
13
14	/**
15	* @var int
16	*/
17	private $norm;
18
19	/**
20	* @param int $norm
21	*
22	* @throws NormalizerException
23	*/
24	public function __construct(int $norm = self::NORM_L2)
25	{
26	if (!in_array($norm, [self::NORM_L1, self::NORM_L2])) {
27	throw NormalizerException::unknownNorm();
28	}
29
30	$this->norm = $norm;
31	}
32
33	/**
34	* @param array $samples
35	*/
36	public function preprocess(array &$samples)
37	{
38	$method = sprintf('normalizeL%s', $this->norm);
39	foreach ($samples as &$sample) {
40	$this->$method($sample);
41	}
42	}
43
44	/**
45	* @param array $sample
46	*/
47	private function normalizeL1(array &$sample)
48	{
49	$norm1 = 0;
50	foreach ($sample as $feature) {
51	$norm1 += abs($feature);
52	}
53
54	if (0 == $norm1) {
55	$count = count($sample);
56	$sample = array_fill(0, $count, 1.0 / $count);
57	} else {
58	foreach ($sample as &$feature) {
59	$feature = $feature / $norm1;
60	}
61	}
62	}
63
64	/**
65	* @param array $sample
66	*/
67	private function normalizeL2(array &$sample)
68	{
69	$norm2 = 0;
70	foreach ($sample as $feature) {
71	$norm2 += $feature * $feature;
72	}
73	$norm2 = sqrt($norm2);
74
75	if (0 == $norm2) {
76	$sample = array_fill(0, count($sample), 1);
77	} else {
78	foreach ($sample as &$feature) {
79	$feature = $feature / $norm2;
80	}
81	}
82	}
83	}