60 lines
1.3 KiB
PHP
60 lines
1.3 KiB
PHP
<?php
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declare (strict_types = 1);
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namespace Phpml\SupportVectorMachine;
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class DataTransformer
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{
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/**
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* @param array $samples
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* @param array $labels
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*
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* @return string
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*/
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public static function trainingSet(array $samples, array $labels): string
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{
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$set = '';
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$numericLabels = self::numericLabels($labels);
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foreach ($labels as $index => $label) {
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$set .= sprintf('%s %s %s', $numericLabels[$label], self::sampleRow($samples[$index]), PHP_EOL);
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}
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return $set;
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}
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/**
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* @param array $labels
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*
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* @return array
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*/
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public static function numericLabels(array $labels): array
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{
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$numericLabels = [];
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foreach ($labels as $label) {
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if (isset($numericLabels[$label])) {
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continue;
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}
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$numericLabels[$label] = count($numericLabels);
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}
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return $numericLabels;
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}
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/**
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* @param array $sample
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*
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* @return string
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*/
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private static function sampleRow(array $sample): string
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{
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$row = [];
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foreach ($sample as $index => $feature) {
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$row[] = sprintf('%s:%s', $index, $feature);
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}
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return implode(' ', $row);
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}
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}
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