LanguageDetector\Sort\PageRank::mult PHP Method

    protected final function mult($a, $b)
    {
        $val = 0;
        if (count($a) != count($a)) {
            throw new Exception("Array shape  mismatch");
        }
        foreach ($a as $index => $value) {
            if (!isset($b[$index])) {
                throw new Exception("Array shape  mismatch");
            }
            $val += $b[$index] * $value;
        }
        return $val;
    }