GraphAware\Reco4PHP\Algorithms\Similarity\CosineSimilarity::getDotProduct PHP Method

    private function getDotProduct(array $xVector, array $yVector)
    {
        $sum = 0.0;
        foreach ($xVector as $k => $v) {
            $sum += (double) ($xVector[$k] * $yVector[$k]);
        }
        return $sum;
    }