33 lines
1.1 KiB
PHP
33 lines
1.1 KiB
PHP
<?php
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/**
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*
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* Function code for the complex log2() function
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*
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* @copyright Copyright (c) 2013-2018 Mark Baker (https://github.com/MarkBaker/PHPComplex)
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* @license https://opensource.org/licenses/MIT MIT
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*/
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namespace Complex;
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/**
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* Returns the base-2 logarithm of a complex number.
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*
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* @param Complex|mixed $complex Complex number or a numeric value.
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* @return Complex The base-2 logarithm of the complex argument.
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* @throws Exception If argument isn't a valid real or complex number.
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* @throws \InvalidArgumentException If the real and the imaginary parts are both zero
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*/
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function log2($complex)
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{
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$complex = Complex::validateComplexArgument($complex);
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if (($complex->getReal() == 0.0) && ($complex->getImaginary() == 0.0)) {
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throw new \InvalidArgumentException();
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} elseif (($complex->getReal() > 0.0) && ($complex->getImaginary() == 0.0)) {
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return new Complex(\log($complex->getReal(), 2), 0.0, $complex->getSuffix());
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}
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return ln($complex)
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->multiply(\log(Complex::EULER, 2));
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}
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