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<?php |
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|
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/** |
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* |
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* Function code for the complex acos() 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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/** |
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* Returns the inverse cosine of a complex number. |
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* |
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* @param Complex|mixed $complex Complex number or a numeric value. |
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* @return Complex The inverse cosine of the complex argument. |
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* @throws Exception If argument isn't a valid real or complex number. |
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*/ |
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function acos($complex) |
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{ |
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$complex = Complex::validateComplexArgument($complex); |
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|
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$square = clone $complex; |
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$square = multiply($square, $complex); |
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$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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$complex->getReal() - $invsqrt->getImaginary(), |
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$complex->getImaginary() + $invsqrt->getReal() |
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); |
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$log = ln($adjust); |
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|
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return new Complex( |
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$log->getImaginary(), |
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-1 * $log->getReal() |
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); |
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} |
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|
