public static function constructFromString($str) {
		$str = strtoupper($str);
		$i = substr($str, -1) == 'I';

		preg_match('/^T[0-9]{1,}/', $str, $matches);
//		print_r($matches);
		$r = $matches[0];

		return new PitchClassSetTransformation($r, $i);
	}