[Summary view]

   1  <?php
   2  
   3  /**
   4   *
   5   * Function code for the complex acosh() function
   6   *
   7   * @copyright  Copyright (c) 2013-2018 Mark Baker (https://github.com/MarkBaker/PHPComplex)
   8   * @license    https://opensource.org/licenses/MIT    MIT
   9   */
  10  namespace Complex;
  11  
  12  /**
  13   * Returns the inverse hyperbolic cosine of a complex number.
  14   *
  15   * @param     Complex|mixed    $complex    Complex number or a numeric value.
  16   * @return    Complex          The inverse hyperbolic cosine of the complex argument.
  17   * @throws    Exception        If argument isn't a valid real or complex number.
  18   */
  19  function acosh($complex)
  20  {
  21      $complex = Complex::validateComplexArgument($complex);
  22  
  23      if ($complex->isReal() && ($complex->getReal() > 1)) {
  24          return new Complex(\acosh($complex->getReal()));
  25      }
  26  
  27      $acosh = acos($complex)
  28          ->reverse();
  29      if ($acosh->getReal() < 0.0) {
  30          $acosh = $acosh->invertReal();
  31      }
  32  
  33      return $acosh;
  34  }