public function getBytes($o)
    {
        $bytes = '';
        for ($i = 0; $i < $this->components; $i ++) {
            if ($this->dimension == 1) {
                $bytes .= $this->numberToBytes($this->value[$i], $o);
            } else {
                for ($j = 0; $j < $this->dimension; $j ++) {
                    $bytes .= $this->numberToBytes($this->value[$i][$j], $o);
                }
            }
        }
        return $bytes;
    }