48 lines
1.0 KiB
PHP
48 lines
1.0 KiB
PHP
<?php
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declare(strict_types=1);
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namespace Phpml\Preprocessing;
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final class LabelEncoder implements Preprocessor
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{
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/**
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* @var int[]
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*/
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private $classes = [];
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public function fit(array $samples, ?array $targets = null): void
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{
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$this->classes = [];
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foreach ($samples as $sample) {
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if (!isset($this->classes[(string) $sample])) {
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$this->classes[(string) $sample] = count($this->classes);
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}
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}
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}
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public function transform(array &$samples, ?array &$targets = null): void
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{
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foreach ($samples as &$sample) {
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$sample = $this->classes[(string) $sample];
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}
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}
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public function inverseTransform(array &$samples): void
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{
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$classes = array_flip($this->classes);
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foreach ($samples as &$sample) {
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$sample = $classes[$sample];
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}
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}
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/**
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* @return string[]
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*/
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public function classes(): array
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{
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return array_keys($this->classes);
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}
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}
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