php-ml/src/Phpml/SupportVectorMachine/DataTransformer.php

102 lines
2.2 KiB
PHP

<?php
declare(strict_types=1);
namespace Phpml\SupportVectorMachine;
class DataTransformer
{
/**
* @param array $samples
* @param array $labels
* @param bool $targets
*
* @return string
*/
public static function trainingSet(array $samples, array $labels, bool $targets = false): string
{
$set = '';
if (!$targets) {
$numericLabels = self::numericLabels($labels);
}
foreach ($labels as $index => $label) {
$set .= sprintf('%s %s %s', ($targets ? $label : $numericLabels[$label]), self::sampleRow($samples[$index]), PHP_EOL);
}
return $set;
}
/**
* @param array $samples
*
* @return string
*/
public static function testSet(array $samples): string
{
if (!is_array($samples[0])) {
$samples = [$samples];
}
$set = '';
foreach ($samples as $sample) {
$set .= sprintf('0 %s %s', self::sampleRow($sample), PHP_EOL);
}
return $set;
}
/**
* @param string $rawPredictions
* @param array $labels
*
* @return array
*/
public static function predictions(string $rawPredictions, array $labels): array
{
$numericLabels = self::numericLabels($labels);
$results = [];
foreach (explode(PHP_EOL, $rawPredictions) as $result) {
if (strlen($result) > 0) {
$results[] = array_search($result, $numericLabels);
}
}
return $results;
}
/**
* @param array $labels
*
* @return array
*/
public static function numericLabels(array $labels): array
{
$numericLabels = [];
foreach ($labels as $label) {
if (isset($numericLabels[$label])) {
continue;
}
$numericLabels[$label] = count($numericLabels);
}
return $numericLabels;
}
/**
* @param array $sample
*
* @return string
*/
private static function sampleRow(array $sample): string
{
$row = [];
foreach ($sample as $index => $feature) {
$row[] = sprintf('%s:%s', $index + 1, $feature);
}
return implode(' ', $row);
}
}