public static function determine($data) : int
    {
        switch (gettype($data)) {
            case 'string':
                return self::CATEGORICAL;

            case 'double':
                return self::CONTINUOUS;

            case 'integer':
                return self::CONTINUOUS;

            case 'resource':
                return self::RESOURCE;

            default:
                return self::OTHER;
        }
    }