40 lines
1.1 KiB
PHP
40 lines
1.1 KiB
PHP
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<?php
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/**
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*
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* Function code for the complex asin() 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 inverse sine of a complex number.
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*
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* @param Complex|mixed $complex Complex number or a numeric value.
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* @return Complex The inverse sine of the complex argument.
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* @throws Exception If argument isn't a valid real or complex number.
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*/
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if (!function_exists(__NAMESPACE__ . '\\asin')) {
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function asin($complex): Complex
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{
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$complex = Complex::validateComplexArgument($complex);
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$square = multiply($complex, $complex);
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$invsqrt = new Complex(1.0);
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$invsqrt = subtract($invsqrt, $square);
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$invsqrt = sqrt($invsqrt);
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$adjust = new Complex(
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$invsqrt->getReal() - $complex->getImaginary(),
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$invsqrt->getImaginary() + $complex->getReal()
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);
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$log = ln($adjust);
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return new Complex(
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$log->getImaginary(),
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-1 * $log->getReal()
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);
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}
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}
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