|
1
|
|
|
<?php |
|
2
|
|
|
|
|
3
|
|
|
declare(strict_types=1); |
|
4
|
|
|
|
|
5
|
|
|
namespace Phpml\FeatureSelection; |
|
6
|
|
|
|
|
7
|
|
|
use Phpml\Exception\InvalidArgumentException; |
|
8
|
|
|
use Phpml\Exception\InvalidOperationException; |
|
9
|
|
|
use Phpml\FeatureSelection\ScoringFunction\ANOVAFValue; |
|
10
|
|
|
use Phpml\Transformer; |
|
11
|
|
|
|
|
12
|
|
|
final class SelectKBest implements Transformer |
|
13
|
|
|
{ |
|
14
|
|
|
/** |
|
15
|
|
|
* @var ScoringFunction |
|
16
|
|
|
*/ |
|
17
|
|
|
private $scoringFunction; |
|
18
|
|
|
|
|
19
|
|
|
/** |
|
20
|
|
|
* @var int |
|
21
|
|
|
*/ |
|
22
|
|
|
private $k; |
|
23
|
|
|
|
|
24
|
|
|
/** |
|
25
|
|
|
* @var array|null |
|
26
|
|
|
*/ |
|
27
|
|
|
private $scores = null; |
|
28
|
|
|
|
|
29
|
|
|
/** |
|
30
|
|
|
* @var array|null |
|
31
|
|
|
*/ |
|
32
|
|
|
private $keepColumns = null; |
|
33
|
|
|
|
|
34
|
|
|
public function __construct(?ScoringFunction $scoringFunction = null, int $k = 10) |
|
35
|
|
|
{ |
|
36
|
|
|
if ($scoringFunction === null) { |
|
37
|
|
|
$scoringFunction = new ANOVAFValue(); |
|
38
|
|
|
} |
|
39
|
|
|
|
|
40
|
|
|
$this->scoringFunction = $scoringFunction; |
|
41
|
|
|
$this->k = $k; |
|
42
|
|
|
} |
|
43
|
|
|
|
|
44
|
|
|
public function fit(array $samples, ?array $targets = null): void |
|
45
|
|
|
{ |
|
46
|
|
|
if ($targets === null || empty($targets)) { |
|
47
|
|
|
throw InvalidArgumentException::arrayCantBeEmpty(); |
|
48
|
|
|
} |
|
49
|
|
|
|
|
50
|
|
|
$this->scores = $sorted = $this->scoringFunction->score($samples, $targets); |
|
51
|
|
|
if ($this->k >= count($sorted)) { |
|
52
|
|
|
return; |
|
53
|
|
|
} |
|
54
|
|
|
|
|
55
|
|
|
arsort($sorted); |
|
56
|
|
|
$this->keepColumns = array_slice($sorted, 0, $this->k, true); |
|
57
|
|
|
} |
|
58
|
|
|
|
|
59
|
|
|
public function transform(array &$samples): void |
|
60
|
|
|
{ |
|
61
|
|
|
if ($this->keepColumns === null) { |
|
62
|
|
|
return; |
|
63
|
|
|
} |
|
64
|
|
|
|
|
65
|
|
|
foreach ($samples as &$sample) { |
|
66
|
|
|
$sample = array_values(array_intersect_key($sample, $this->keepColumns)); |
|
67
|
|
|
} |
|
68
|
|
|
} |
|
69
|
|
|
|
|
70
|
|
|
public function scores(): array |
|
71
|
|
|
{ |
|
72
|
|
|
if ($this->scores === null) { |
|
73
|
|
|
throw new InvalidOperationException('SelectKBest require to fit first to get scores'); |
|
74
|
|
|
} |
|
75
|
|
|
|
|
76
|
|
|
return $this->scores; |
|
77
|
|
|
} |
|
78
|
|
|
} |
|
79
|
|
|
|
php-ai /
php-ml
