38 lines
765 B
PHP
38 lines
765 B
PHP
<?php
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declare(strict_types=1);
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namespace Phpml\Math\Distance;
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use Phpml\Exception\InvalidArgumentException;
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use Phpml\Math\Distance;
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class Euclidean implements Distance
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{
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/**
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* @throws InvalidArgumentException
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*/
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public function distance(array $a, array $b): float
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{
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if (count($a) !== count($b)) {
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throw new InvalidArgumentException('Size of given arrays does not match');
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}
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$distance = 0;
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foreach ($a as $i => $val) {
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$distance += ($val - $b[$i]) ** 2;
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}
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return sqrt((float) $distance);
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}
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/**
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* Square of Euclidean distance
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*/
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public function sqDistance(array $a, array $b): float
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{
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return $this->distance($a, $b) ** 2;
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}
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}
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