41 lines
802 B
PHP
41 lines
802 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 Minkowski implements Distance
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{
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/**
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* @var float
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*/
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private $lambda;
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public function __construct(float $lambda = 3.0)
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{
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$this->lambda = $lambda;
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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($b)) {
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throw InvalidArgumentException::arraySizeNotMatch();
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}
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$distance = 0;
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$count = count($a);
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for ($i = 0; $i < $count; ++$i) {
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$distance += pow(abs($a[$i] - $b[$i]), $this->lambda);
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}
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return (float) pow($distance, 1 / $this->lambda);
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}
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}
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