/**
* @param array $sample
*
* @return array
*
* @throws \Phpml\Exception\InvalidArgumentException
*/
private function kNeighborsDistances(array $sample)
{
$distances = [];
foreach ($this->samples as $index => $neighbor) {
$distances[$index] = $this->distanceMetric->distance($sample, $neighbor);
}
asort($distances);
return array_slice($distances, 0, $this->k, true);
}
/**
* @param array $localSample
* @param array $samples
*
* @return array
*/
private function getSamplesInRegion($localSample, $samples)
{
$region = [];
foreach ($samples as $index => $sample) {
if ($this->distanceMetric->distance($localSample, $sample) < $this->epsilon) {
$region[$index] = $sample;
}
}
return $region;
}