38 lines
683 B
PHP
38 lines
683 B
PHP
<?php
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declare(strict_types=1);
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namespace Phpml\NeuralNetwork\ActivationFunction;
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use Phpml\NeuralNetwork\ActivationFunction;
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class HyperbolicTangent implements ActivationFunction
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{
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/**
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* @var float
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*/
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private $beta;
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public function __construct(float $beta = 1.0)
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{
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$this->beta = $beta;
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}
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/**
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* @param float|int $value
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*/
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public function compute($value): float
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{
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return tanh($this->beta * $value);
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}
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/**
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* @param float|int $value
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* @param float|int $computedvalue
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*/
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public function differentiate($value, $computedvalue): float
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{
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return 1 - $computedvalue ** 2;
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}
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}
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