Current Path : C:/xampp/htdocs/moodle/lib/mlbackend/php/phpml/src/Phpml/Dataset/ |
Current File : C:/xampp/htdocs/moodle/lib/mlbackend/php/phpml/src/Phpml/Dataset/SvmDataset.php |
<?php declare(strict_types=1); namespace Phpml\Dataset; use Phpml\Exception\DatasetException; use Phpml\Exception\FileException; class SvmDataset extends ArrayDataset { public function __construct(string $filePath) { [$samples, $targets] = self::readProblem($filePath); parent::__construct($samples, $targets); } private static function readProblem(string $filePath): array { $handle = self::openFile($filePath); $samples = []; $targets = []; $maxIndex = 0; while (false !== $line = fgets($handle)) { [$sample, $target, $maxIndex] = self::processLine((string) $line, $maxIndex); $samples[] = $sample; $targets[] = $target; } fclose($handle); foreach ($samples as &$sample) { $sample = array_pad($sample, $maxIndex + 1, 0); } return [$samples, $targets]; } /** * @return resource */ private static function openFile(string $filePath) { if (!file_exists($filePath)) { throw new FileException(sprintf('File "%s" missing.', basename($filePath))); } $handle = fopen($filePath, 'rb'); if ($handle === false) { throw new FileException(sprintf('File "%s" can\'t be open.', basename($filePath))); } return $handle; } private static function processLine(string $line, int $maxIndex): array { $columns = self::parseLine($line); $target = self::parseTargetColumn($columns[0]); $sample = array_fill(0, $maxIndex + 1, 0); $n = count($columns); for ($i = 1; $i < $n; ++$i) { [$index, $value] = self::parseFeatureColumn($columns[$i]); if ($index > $maxIndex) { $maxIndex = $index; $sample = array_pad($sample, $maxIndex + 1, 0); } $sample[$index] = $value; } return [$sample, $target, $maxIndex]; } private static function parseLine(string $line): array { $line = explode('#', $line, 2)[0]; $line = rtrim($line); $line = str_replace("\t", ' ', $line); return explode(' ', $line); } private static function parseTargetColumn(string $column): float { if (!is_numeric($column)) { throw new DatasetException(sprintf('Invalid target "%s".', $column)); } return (float) $column; } private static function parseFeatureColumn(string $column): array { $feature = explode(':', $column, 2); if (count($feature) !== 2) { throw new DatasetException(sprintf('Invalid value "%s".', $column)); } $index = self::parseFeatureIndex($feature[0]); $value = self::parseFeatureValue($feature[1]); return [$index, $value]; } private static function parseFeatureIndex(string $index): int { if (!is_numeric($index) || !ctype_digit($index)) { throw new DatasetException(sprintf('Invalid index "%s".', $index)); } if ((int) $index < 1) { throw new DatasetException(sprintf('Invalid index "%s".', $index)); } return (int) $index - 1; } private static function parseFeatureValue(string $value): float { if (!is_numeric($value)) { throw new DatasetException(sprintf('Invalid value "%s".', $value)); } return (float) $value; } }